*Anopheles ; *DDT ; *Dieldrin ; *Malaysia

Normal Bangkok strain of X. cheopis which had little resistance to DDT in 1966 became moderately resistant in 1972 without any direct exposure to the insecticide. It was analyzed that the causes of resistance gaining were as follows. First, the possibility of being exposed unconsciously to DDT spray under malaria eradication program could not be ruled out, even in laboratory as far as ventilation windows would be open sometime. Insecticides from air spray through the window influenced the fleas kept in the pools. Second, it may be said that initial resistance to DDT has become greater and greater ecologically without any exposure of insecticides. A highly resistant strain of X. cheopis which survived after contacting 4% DDT for five times during one year period was obtained in the laboratory and it showed 100% survival at the highest concentration (4%) of DDT paper by 24 hour exposure. The hybrid forms between normal Bangkok strain and artificially mutated "Resistant Strain" were obtained by mixing the above two colonies. Regardless to the sexes of both ancestors, the results of resistance tests of hybrids showed that artificially gained resistance of fleas to DDT was inherited possibly by recessive hereditary role by pheonotype.
parasitology-arthropoda-flea-Xenopsylla cheopis ; resistance-DDT ; Bangkok strain ; DDT

The authors carried out two series of field test to determine the basic lines of DDT and Dieldrin susceptibility of Anopheles sinensis at Andong(1961) and Yoju(1962), where malaria endemicity is relatively high in Korea. Tests were performed in accordance with the standard method established by the World Health Oraganization(1960). The results were summarized as follows: The LC-50 of DDT for A. sinensis caught at Andong as 1.5 %, while for the same species in Yoju was 1.3 %. The LC-50 of Dieldrin for A. sinensis caught at Andong was 0.075 %, while the LC-50 for the same species at Yoju was 0.07 %. These results therefore indicate Anopheles sinensis, as the malaria vector species in Korea, is susceptible to DDT and Dieldrin.
parasitology-protozoa-Plasmodium vivax ; chemotherapy-malaria ; Anopheles sinensis ; DDT ; Dieldrin

A survey on rats and rat-fleas was performed in costal area of Korea during 1972 in Inchon, Kunsan, Yosu, Busan and other areas. The number of the caught rats was 1,448. Total number of collected fleas was 2,480. Geographical distribution were described. Flea index was in 1.71 total. Mothly flea indices were 0.35-0.84 in January to March, 2.13-2.59 in April to June, 0.58 in July and 1.82-4.91 in August to November. Mortality rate of X. cheopsis to various concentration of DDT in 1 hour exposure were 43.8 % in 4.0 %, 30.4 % in 1.0 %. In 24 hours exposure, the mortalities were 100 % in 4.0 %, 91.5 % in 2.0 %, 73.5 % in 1.0 % and 37.0 % in 0.5 % DDT.
parasitology-arthropoda-flea ; rat ; Xenopsylla cheopis ; Monopsyllus anisus ; Nosopsyllus fasciatus ; Leptopsylla segnis ; Ctenophthalmus cong. congeneroides ; Ctenocephalides canis ; Nosopsyllus nicanus ; Rhadinopsylla attenuata ; epidemiology ; insecticide ; DDT-chemotherapy ; DDT

The results of the tests carried out in 1971 strongly suggested that a considerable portion of the flea population in MR 2 had developed resistance not only against DDT but also malathion and dieldrin. There is also the possibility of the fleas developing a resistance to diazinon and lindane. Thus careful consideration should be given to the continuous use of diazinon. In areas where fleas had developed a resistance to malathion, further tests should be conducted continuously to confirm the possible development of resistance. Other insecticides which have not been used in Vietnam for any purpose should be ready to be substituted, if the development of resistance is confirmed.
parasitology-arthropoda-flea-Xenopsylla cheopis ; resistance ; Vietnam ; DDT ; dieldrin ; diazinon ; lindane ; malathion

In the summer of 1969 from July through October, authors carried out a study of susceptibility in adult female bed bug(Cimex lectularius) in order to ascertain any development of resistance to insecticides in Korea. The test to DDT and Dieldrin was performed in laboratory by the continuous exposure of residues method, with standard impregnated paper used for adult mosqitoes. Some results so far obtained can be summarised as follows: LC(50) were 2.839% in DDT and 0.167% in Dieldrin. The resistance has been arisen 2.4-2.9 times in DDT and 1.6-2.4 times in Dieldrin as compared with London laboratory strain, but they were susceptible 1.4 times in DDT and 180 times in Dieldrin as compared to Israel resistance strain.
parasitology-arthropodology-bed bug-Cimex lectularius ; prevention ; chemotherapy ; resistance ; DDT ; dieldrin

OBJECTIVES: The study was conducted to estimate the carcinogenic risks from the ingestion of some carcinogenic pesticides (CPs) in vegetables sampled at a local agricultural product market in Seoul. METHODS: After applying a hazard identification step, we selected four pesticides, such as DDT, dieldrin, folpet, and heptachlor epoxide, for this risk assessment. Concentrations of each pesticide were measured from randomly sampled vegetables. In order to estimate the human exposure levels, we combined the concentration of pesticides in the vegetables with consumption rate of those vegetables. Three scenarios were hypothesized for human exposure assessment. Scenario I was the most conservative which supposed the undetected CPs would be the detection limit values. Scenario II was assumed that the undetected CPs would be a half of the detection limit values, and finally scenario III merely considered only values greater than the detection limit values. We finally presented the estimated carcinogenic risks on the basis of the traditional risk assessment procedure suggested by U.S. EPA. RESULTS: Pesticides including DDT, dieldrin, folpet and heptachlor epoxide were detected in 9 samples (6%) in the range of 0.0006~0.09ppm. The daily intake levels of carcinogenic pesticides were estimated in the range of 0.0009~0.0079 microgram/day. As we expected, excess cancer risks based on scenario I was also the highest (1.1x10-8~ 5.5x10-5). CONCLUSIONS: We found that the estimated risks from the pesticides we investigated were not serious. We, however, propose that a continuos monitoring is needed to make sure for the protection of public health.
DDT ; Dieldrin ; Eating ; Heptachlor Epoxide ; Humans ; Korea* ; Limit of Detection ; Pesticides* ; Public Health ; Risk Assessment* ; Seoul ; Vegetables*

PURPOSE: To evaluate the effects of the lateral tarsal strip procedure in the treatment of lacrimal pump dysfunction related to lower lid laxity. METHODS: This study investigated 46 eyes of 35 patients diagnosed with dysfunction of the lacrimal pump on which the lateral tarsal strip procedure was performed between June 2001 and February 2004. We retrospectively reviewed patients' medical records for information including age, gender, history, follow-up period, change of fluorescein dye disappearance test (DDT), tear meniscus height (TMH), symptoms, and complications. RESULTS: Improvement of tearing was noted in 26 patients (78.8%). Thirty-seven eyes (80.5%) were improved by more than 1 grade on DDT. Significant improvement above 2 grades was observed in 16 eyes (34.7%). With respect to age, 62.5% of 3rd-decade patients improved most effectively by more than 2 grades on DDT. Postoperative TMH compared with preoperative TMH measures were significantly lower according to statistics. The most common complication was discomfort or tenderness over the orbital rim (13.0%). CONCLUSIONS: Performance of the lateral tarsal strip procedure for tearing caused by dysfunction of the lacrimal pump and related to lower lid laxity improved patients' tearing, DDT and TMH status. We therefore expect the lateral tarsal strip procedure to be effective in the surgical treatment of lacrimal pump dysfunction secondary to lower eyelid laxity.
DDT ; Eyelids ; Fluorescein ; Follow-Up Studies ; Humans ; Medical Records ; Nasolacrimal Duct* ; Orbit ; Retrospective Studies

During the summer season(July-August) in 1967, the insecticide tests for resistance on adult A. sinensis and C. tritaeniorhynchus were carried out in Gobu-Myun Jeongup-Gun, Chollapuk-Do, where many Japanese encephalitis cases occur every year. The mortality by 4.0% DDT in A. sinensis was 88.9% and by 4.0% dieldrin was 84.4%. Therefore the LC-50 of DDT for A. sinensis was 1.75%, while LC-50 of dieldrin was 1.1%. The mortality by 4.0% DDT in C. tritaeniorhynchus was 36.7%, and by 4.0% dieldrin was 6.0% The result indicates that A. sinensis in Korea is susceptible to DDT and resistant to dieldrin. C. tritaeniorhynchus is highly resistant to both DDT and dieldrin.
parasitology-arthropoda ; vector ; mosquito ; Culex tritaeniorhynchus ; Anopheles sinensis ; chemotherapy ; DDT ; dieldrin

In Tansan and Wondang m 1960, and m Guidandong and Yongju-eup in 1961, routine entomological work was carried out according to the plan of operation for the ma1aria pre-eradication survey. During the present work, six anopheline mosquito species were recorded as follows: 1. Anopheles (Anopheles) sinensis Wiedmann, 1828. 2. Anopheles (Anopheles) sineroides Yamada, 1925. 3. Anopheles (Anopheles) lesteri Baisas and Hu, 1936. 4. Anopheles (Anopheles) koreicus koreicus Yamada and Watanabe, 1918. 5. Anopheles (Anopheles) koreicus edwardsi Yamada, 1925, and, 6. Anopheles (Anopheles) lindesayijaponicus, Yamada, 1918. A. sinensis is the most predominant species, although A. koreicus koreicus was also found to be predominant after A. sinensis in Guidandong (a mountainous area) A. sineroides is the next most predominant species after A. sinensis. Anopheline mosquitos begin to appear from late April or May and disappear in October each year. The resting places for the anopheline mosquitos are mainly cow sheds and outdoors. The population density of A. sinensis in cow sheds shows a peak either in June or in July in most places with a second small peak in late August or in September. Night biting habits appear to be active throughout the whole night but are more active from sunset to midnight. Most of the anophelines caught appeared to be zoophilic; however, the results of precipitin tests for A. sinensis showed a likelihood that these are facul-tative anthropophilic. Dissection of salivary glands in the present study of 2736 female A. sinensis mosquitos failed to show or to prove the presence of sporozoites, although sinensis is suspected as a potential of malaria. The body weight, moisture and fat content in A. sinensis appeared to decrease in July from a high peak in June and then to increase again m September. Insecticide susceptibility tests proved that the species was susceptible to DDT and Dieldrin in Guidandong and Yoju. The bionomics of A. sineroides, A. koreicus koreicus, A. koreicus edwardsi, A. lesteri and A. Iindesayi ja-ponicus was discussed; the latter two species are probably the first to be recorded in Korea. The mosquitos caught in hibernating places were found to be nulliparous and to have sperms in the spermathecae during the winter months. Anopheline hibernated probably in the adult stage.
Adult ; Anopheles* ; Body Weight ; Culicidae* ; DDT ; Dieldrin ; Ecology ; Female ; Humans ; Korea* ; Malaria ; Population Density ; Precipitin Tests ; Salivary Glands ; Spermatozoa ; Sporozoites