Showing papers by "Seoul National University published in 1973"
31 citations
TL;DR: Distribution of Sparganum mansoni in 7 species of terrestrial snakes in Wonju City was surveyed and authors believe that Zamenis spinalis was firstly recorded as intermediate host of this larval worm in Korea.
Abstract: Distribution of Sparganum mansoni in 7 species of terrestrial snakes in Wonju City was surveyed. All kinds of snakes were found to be served as intermediate hosts of this larval worm except Elaphe schrenkii which has already been recorded as important host. Authors believe that Zamenis spinalis was firstly recorded as intermediate host of Sparganum mansoni in Korea. Some aspects of infection status, host-parasite relations and sources of human infection were briefly discussed.
17 citations
TL;DR: Study of filariasis to determine important factors involved in its ecology was carried out on Che Ju Island for three consecutive years from 1968 to 1970 in seven villages, three coastal villages and four islets remote from the main island.
Abstract: Study of filariasis to determine important factors involved in its ecology was carried out on Che Ju Island for three consecutive years from 1968 to 1970 in seven villages, three coastal villages and four islets remote from the main island One village which was located in mountainous area far from the coast was surveyed to serve as control area About 90% of population inhabiting the study area had at least one blood smear during the three-year period; about one third had three blood smears, and a little over one third had two, and the rest only one examination Animal and mosquito surveys were carried out at the same period Followings are the results obtained: 1 All human cases but several had microfilariae identical to the description of B malayi The several cases who had morphologically different microfilariae from that of B malayi need further study for definite conclusion 2 Five persons randomly sampled from Mf positives and bled every two hours demonstrated nocturnal periodicity between 9 pm and 3 am 3 Human is considered to be only reservoir host for human filariasis in the area since animal survey and experimental exposure to the infective larvae of human filaria species showed failure to infect animals 4 Microfilaria rate, microfilaria density, prevalence of elephantiasis varied by area and age with correlation, which indicated cumulative process of the parasite by repeated exposure and development of host immunity to certain extent 5 Clinical manifestation of filariasis (symptom complex and elephantiasis ) taken from history and inspection was low in its prevalence with range of 09% 118% of total population Only 52% of 517 Mf positives had the clinical manifestation 248% of 109 persons with clinical manifestation had microfilaria; 429% with symptom complex only, 231% with both symptoms and elephantiasis, and none with elephantiasis only were microfilaria positive 6 Ae togoi was the only species infected with the filaria Mosquito infection rate by area showed positive correlation to the Mf rate and density of human population; where the Mf rate and density were high, the mosquito infection rate also high
14 citations
TL;DR: In the suboesophageal ganglion of the Bombyx mori, the diapause-regulator producing cells which may give information to the diaperause-factor cells were found by means of electron microscopy as discussed by the authors.
12 citations
TL;DR: It was conclusively indicated that the chemotherapeutic response to low dosage schedule within shorter length of treatment was equal to that of larger doses in long term medication from the point of the reduction in microfilaria, and particularly the resulting side-reactions were also reduced in theLow dosage schedule.
Abstract: A series of 250 patients with filariasis due to periodic type of Brugia malayi was selected for the mass treatment with diethylcarbamazine from two areas in Cheju-Do. Two types of dosage schedules have been employed: the one was the conventional dosage schedule (uninterrupted dose of 6 mg/kg once daily 6 times repeated with an interval of one or two month totaling 72 mg/kg), and the other was the low dosage schedule (uninterrupted dose of 0.5, 1, 2, 4, 6 mg/kg body weight given once a day with an additional 6 mg/kg once daily totaling the maximum 37.5 mg/kg). The relative effectiveness of those two schedules was evaluated under the basis of the effects on microfilaria counts and the results of analysis of side-reactions observed. The results obtained in this experiment are summarized as it follows. In the conventional dosage treatment, 118 out of 141 microfilaria positives treated (83.7%) became negative and microfilaria reduction rate was about 99%. However, in the low dosage treatment, 35 out of 43 positives treated (85.4%) became negative and reduction rate of microfilaria, 99.5% in average. Total dose and duration of treatment were 72 mg/kg and about 60 days in the former schedule but it were maximum 37.5 mg/kg and 10 days in the latter. The recurrence of filariasis after treatment in both conventional and low dosage was negligible. Comparative analyses regarding the resulting side-reactions between the two schedules were made on their frequency, severity, onset and duration and relationship with microfilaria density. The febrile reaction was most frequently observed in 80.5% in the conventional, 43.9% in the low dosage schedule. The main side-reactions usually appeared within 6 to 10 hours and lasted 48 to 72 hours in the former threament, however they occurred in 7 to 8 hours and lasted 24 to 43 hours in the latter dosage schedule. It is assumed that the side-reactions are not directly related with the microfilaria count. However, the febrile reaction seems to be correlated with microfilaria density if it is above a certain limit. The presence of adult worm in a lymphnode involved with local reaction was ascertained from the biopsy specimens performed and local reactions such as lymphangitis and lymphadenitis after drug administrations were assessed from clinical and pathological point of view. It was conclusively indicated that the chemotherapeutic response to low dosage schedule within shorter length of treatment was equal to that of larger doses in long term medication from the point of the reduction in microfilaria, and particularly the resulting side-reactions were also reduced in the low dosage schedule.
6 citations
TL;DR: Mosquito infection rates were also dropped markedly in areas where mf positive were mass treated and DDT spray did not influence human mf rate and mosquito infection rate.
Abstract: This study was carried out for three years from 1968 to 1970. Three coastal villages and four remote islets of Che Ju Island were surveyed and 90% of all inhabitants were blood smeared. These study areas were grouped into five according to its characteristic for evaluation of mass treatment with diethylcarbamazine citrate (Hetrazan U.S.P.) and insecticide spray in control of human filariasis. To set baseline up for control group, placebo was administered. Followings are the results obtained: 1. 81.1% of all mf positives accepted and completed the mass chemotherapy; main reason for refusal was side reactions told by neighboring villagers who experienced them. 2. 6 mg of hetrazan/kg B.W. X12 doses given every day turned mf postives to mf negative in 92.1%. The patients who had high mf density remained mf positive in 16.5% whereas only 2.1% for low mf density. 3. 73.8% of mf positives after the treatment showed marked decrease in mf density. Most of them to less than 15n mg/20 mm(3) of blood that can not infect mosquito effectively. 4. Mosquito infection rates were also dropped markedly in areas where mf positive were mass treated. 5. Side reaction induced by diethylcarbamazine was frequent(64%-90%) and various. The most frequent symptom was headache and fever. 6. DDT spray did not influence human mf rate and mosquito infection rate.
5 citations
TL;DR: There is a close relationship in vegetative structure and in the ontogeny of the reproductive structure toLomentaria, especially toL.
Abstract: Although the species has been known for more than 70 years, no published accounts have been made of the details of development of the reproductive structures ofBinghamia californica J. Ag., a member of the Rhodymeniales of limit d distribution in the eastern and western Pacific. The present studies indicate that there is a close relationship in vegetative structure and in the ontogeny of the reproductive structure toLomentaria, especially toL. hakodatensis Yendo.
4 citations
TL;DR: Polyphase envelope detection makes it possible to detect the envelope of the impressed AM signal to any desired degree of accuracy even when the ratio of the frequency of the carrier to that of the modulating signal approaches unity.
Abstract: When the ratio of the frequency of the carrier to that of the modulating signal becomes less than approximately 10:1, AM detectors become unable to detect the impressed modulation in a satisfactory manner. Distortion due to transient charging and discharging phenomena in the diode circuit during detection of wide-band AM signals has imposed limitations on channel capacity in AM and FM wide-band multiplexing systems. This paper presents and analyzes polyphase envelope detection as a suitable method of solving the problem. This technique makes it possible to detect the envelope of the impressed AM signal to any desired degree of accuracy even when the ratio of the frequency of the carrier to that of the modulating signal approaches unity. The paper shows the results of an experiment that was carried out to verify the theory.
3 citations
3 citations
TL;DR: Moderate amount of blackening showed in the subcuticular muscle fibers, testes, ovary, cirrus sac, oral sucker and pharynx, and slightly labeled particles were in the reticular tissue, ventral sucker, intestinal epithelium, prostate, uterus and ova.
Abstract: Autoradiographic study was performed in order to know the distribution of exogenous radioactive substance, (3)H-6-Thymidine, by liver fluke, Fasciola hepatica. The worms were maintained in vitro for 1 hour, at 37 degrees C, in Tyrode solution containing (3)H-6-Thymidine. After the incubation, the worms were sectioned and autoradiographed by applying the techniques of microautoradiography. The black grains derived from labeled substance were highly accumulated in the vitelline duct and vitelline glands. Moderate amount of blackening showed in the subcuticular muscle fibers, testes, ovary, cirrus sac, oral sucker and pharynx. Slightly labeled particles were in the reticular tissue, ventral sucker, intestinal epithelium, prostate, uterus and ova. There can hardly be found the black grains in the cuticle.
TL;DR: In this paper, the changes of amino acids in the silkworm eggs were investigated in a special relation to the diapsuse of the Silkworm egg and the results showed that the amount of alanine increased in the non-hibernating lethal and HCl-treated eggs, comparing with the diapause eggs.
Abstract: As for the changes of amino acids in the silkworm eggs, YOSHITAKE et al. (1950) reported that phenylalanine, leucine, valine, histidine, serine, glycine, methionine, and taurine increased in amount during embryonic development. SASAKI et al. (1957) also observed the changes in amounts of amino acids components in eggs during embryonic development, and found that only histidine increased after the refrigeration of the eggs, on the contrary TAKAHASHI (1956) found that proline and histidine increased after the refrigeration. On the other hand, TAKES and NAGASHIMA (1970) revealed that small change in the amount of alanine occurred in the non-hibernating lethal and HCl-treated eggs, comparing with the diapause eggs. Moreover they found that phenylalanine, leucine, and iso-leucine were small in quantity in the HCl-treated eggs. As far as the authors are aware, few studies on the changes of amino acids have been done in special relation to diapsuse of the silkworm egg. In the present experiments preliminary results were displayed on the item.