PubMed Health⌕ Search

Biomedical subjects

H I Ree

Publications and source records attributed to H I Ree.

36 records · Page 2Linked to original sources
PubMed1997

Development of mass rearing technique of Tyrophagus putrescentiae (Acari: Acaridae) found in house dust.

A storage mite, Tyrophagus putrescentiae, is recently known to be widely distributed in Korea, being commonly found in house dust, and may, therefore, be allergenically important. The purpose of this study was to develop mass rearing techniques for supplying a large quantity of allergens. The laboratory mouse food powder gave the highest yield, showing 1,251.5-fold increase in number after 10 weeks, and the mixed powder of laboratory mouse food and yeast (1:1) also gave same level of the production (1,203.1-fold increase in week 10). Several different combinations of temperature and relative humidity conditions were compared, and the maximum propagation was obtained at 25 degrees C and 64% RH, showing 960-fold increase in number. When the same amount of culture media was used, the size of the culture container did not significantly influence the quantitative yield of T. putrescentiae mites.

Acari↗
PubMed1997

Geographical distribution of vectors and sero-strains of tsutsugamushi disease at mid-south inland of Korea.

Studies of geographical distributions and relative population densities of the vector mites of tsutsugamushi disease were carried out in October 1996 at 12 locations of the mid-south inland of the Korean peninsula, where chigger mites have been never studied. Of 177 field rodents and insectivores collected, 154 (87.0%) were Apodemus agrarius. Total 25,707 chigger mites were collected and 14 species were identified, of which Leptotrombidium pallidum was predominant (79.8%) and L. palpale the next (8.9%). L. pallidum, the vector species, was widely distributed in all study areas, showing the highest density at Cho-o 2-dong, Sangju-si (chigger index 201.8), and the lowest at Tanwol-dong. Chungju-si (chigger index 40.7). The other vector species, L. scutellare was found only at the southern part of the study area such as Yobae and Mipyong, Kumrunggun and Unsu, Kimchon-si. The northernmost areas of the L. scutellare distribution were coincided with the areas where anual mean air temperature is above 10.0 C. Among 157 A. agrarius sera tested, 48.3% was Karp, 1.7% Gilliam and 3.3% Kuroki. The rest of the sera were not able to determine the sero-type because of the cross antigen-antibody reactions among the tested sero-types.

Animals↗
PubMed1996

[Population density of chigger mites, the vector of tsutsugamushi disease in Chollanam-do, Korea].

The geographical distribution and population density of rodents and chigger mites at six localities of Chollanam-do were investigated from October to December in 1993. Among total 142 field rodents collected by the modified Chemla wooden traps, 131 rodents were Apodemus agrarius (92.3%) and 11 were Crocidura lasiura (7.7%). Out of 142 field rodents, 92 were parasitized by chiggers, showing 69.0% of the infestation rate and 74.2 of the chigger index. Infestation rate and chigger index of A. agrarius and C. lasiura were 73.3%, 80.4 and 18.2%, 0.5, respectively. From the trapped field rodents, 10,532 chiggers were collected and identified with 11 species of 4 genera. Leptotrombidium pallidum, the vector species of tsutsugamushi disease, was the dominant species, showing 8,038 chiggers (76.3%). L. scutellare was the second dominant species showing 1,359 chiggers (12.9%). The distribution of chigger mites was clearly localized by the species, showing the different dominant species according to localities. The predominant species was L. scutellare (100%) in Changhung-gun, L. scutellare (41.5%) in Posong-gun, L. pallidum (88.8%) in Hwasun-gun, L. pallidum (59.2%) in Koksong-gun, L. zetum (77.3%) in Hampyong-gun, and L. palpale (63.4%) in Tamyang-gun. Regarding to the geographical distribution of chigger population density, the infestation rate and chigger index was most high in Hwasun-gun as 62.4% and 216.2 respectively, and next high in Koksong-gun as 22.4% and 77.7% respectively.

Animals↗
PubMed1996

[Identification and characterization of allergens of Chironomus flaviplumus adults (Chironomidae, Diptera) in mice].

Non-biting midges (Chironomidae, Diptera) are one of the largest insect families, which are distributed worldwidely and are found in nearly all types of inland waters. They are known to be aggressive inhalant allergens which cause allergenic diseases. In this study, the crude antigens of Chironomus flaviplumus adults which are most widely distributed in Korea were extracted, and their allergens were analyzed with the sera from experimentally sensitized mice. The mice were immunized with 1 microg or 10 microg of the crude antigens, respectively, and the specific serum IgE levels were measured by both ELISA and passive cutaneous anaphylaxis (PCA) techniques. The highest levels of both total IgE and chironomid-specific IgE were found in the mouse sera obtained after 9 weeks of the first injection with 1 mu g crude antigen. The crude antigen was separated into 16-18 protein bands on gel by SDS-PAGE. The crude extract was assessed by SDS-PAGE/immunoblot analysis. One IgE-binding band (65 kDa) was detected by developing with colorimetric substrate, and 4 IgE-binding bands (65, 52, 35 IgE-binding and 25 kDa) by developing with CSPD chemiluminescent substrate. The SDS-PAGE gel of the crude extract of chironomid adults was equally cut into 30 pieces and each of them was eluted to isolate proteins by molecular weight, and the allergenicity of each eluate was assessed by applying P-K test on rats. Proteins of 65, 35 and 15 kDa showed the highest P-K titer (x 512) which was 16 times higher than that of the crude extract (x 32). The P-K titer of 52 kDa protein was also 4 times higher (x 128) than that of the crude extract, whereas the 25 kDa protein poorly responded, which seemed not antigenic. In conclusion, the present result in mice demonstrated that adults of Chironomus flaviplumus, a predominent species in Korea, cause allergenic diseases and the main allergens are 65, 52, 35 and 15 kDa proteins, of which 65 kDa protein seems to be a main allergen.

Allergens↗
PubMed1996

[A human case of internal myiasis in Korea].

A 71-year old male patient was admitted in Inha hospital due to right facial palsy, quadriplegia and aphasia. This patient was operated to replace his heart values 7 years ago and has been treated with Coumarin, an anti-coagulant drug, to prevent the formation of thrombus in the heart. A number of fly maggots continuously crawled out from the nasogastric tube set up for supplying a liquid diet and patient's mouth for 2 days until his death in the intensive care unit of hospital. These maggots were about 11.5 mm long on the average and identified as genus Lucilia belonging to family Calliphoridae. The lesion of this myiasis case might be regarded in the gastro-intestinal system of patient. This is the first report of an internal myiasis case in Korea.

Aged↗
PubMed1995

Comparative epidemiological studies on vector/reservoir animals of tsutsugamushi disease between high and low endemic areas in Korea.

Comparative epidemiological studies on vector reservoir animals of tsutsugamushi disease were carried out in between south coast (the highest endemic) areas and east coast (low endemic) areas in October 1993. Fauna of field rodents and their population densities were not different between two areas. Antibody positive rate of Apodemus agrarius sera was higher in east coast (43.2% in south coast and 63.6% in east coast). High correlation (r = 0.87) was shown between antibody positive rate of A. agrarius sera and population density of the vector mites (Leptotrombidium scutellare and L. pallidum). L. scutellare was predominant in south coast, showing 110.6 chigger index (74.9% of the total chiggers), whereas L. pallidum was predominant in east coast, showing 126.3 chigger index (60.4% of the total). As higher population density of L. scutellare was found in south coast where the prevalence rate of tsutsugamushi disease is the highest, it is believed that L. scutellare is more important vector species than L. pallidum, which may result from more frequent vector-human contact.

Animals↗
PubMed1993

[Seasonal distribution of chigger mites in the Kanghwa Island and Yongjong Island].

Seasonal distribution of chigger mites in the Kangwha Island and Yongjong Island was studied during the period of October 1992-August 1993. From 42 field rodents collected, 1,290 chiggers were obtained and 8 species of 4 genera were identified. In the Kanghwa Island, Leptotrombidium pallidum was the predominant species through all seasons with the percentage of 93.0%. Whereas, in the Yongjong Island, L. palpale was the predominant species with the percentage of 38.4% and L. pallidum was not found.

Animals↗
PubMed1992

Study on vector mites of tsutsugamushi disease in Cheju Island, Korea.

Because no reference on trombiculid mites (Acarina: Trombiculidae) in Cheju Island where tsutsugamushi disease is highly endemic had been available, studies on trombiculid mites in Cheju Island were implemented during the period of August 1991-April 1992, and the results obtained are summarized as follows: (1) The species and numbers of the field rodents collected were 143 Apodemus agrarius chejuensis (92.3%), 11 Crocidura lasiura (7.1%) and 1 Micromys minutus (0.6%). From total 12,075 chiggers harvested, 9 species of 4 genera in Trombiculidae were identified. (2) The predominant species through all seasons was L. zetum (43.3%), followed by L. orientale (27.4%) and L. scutellare (26.6%). However, in autumn when the most cases of tsutsugamushi disease occur, L. scutellare was prominently predominant, having 79.8% of the collected chiggers. (3) Among 1,142 L. scutellare examined for Rickettsia tsutsugamushi by means of IFA test, 6 individuals were found positive showing 0.5% of infection rate. This is the first finding that L. scutellare is the second vector species of tsutsugamushi disease in Korea. (4) Antibody positive rate of A. agrarius chejuensis sera were 31.2% (44/139), and 1 M. minutus serum was also found positive. The seropositive rates by season were not so significantly different.

Animals↗
PubMed1992

Mass treatment of head louse infestation with Sumithrin powder in primary schools in Korea.

A mass treatment of head louse infestation with Sumithrin powder (0.4% phenothrin) in primary school children was implemented during the period of September 1991-May 1992. The infestation rate of total 2,515 children was 38.6% in average (21.2% in boys and 57.2% in girls). The reduction rate of head louse infestation was 93.4% with a single treatment and 94.8% with double consecutive treatments with about 10 days interval, which indicated that a single treatment would be recommended for the mass treatment in the community. Long term follow-up after Sumithrin powder application for head louse control in a primary school showed that the infestation rate dropped from 33.1% before treatment to 5.4% by seven months after treatment, giving a 83.4% reduction rate.

Age Factors↗
PubMed1991

Determination of the vector species of tsutsugamushi disease in Korea.

In order to determine the vector species of tsutsugamushi disease in Korea, chiggers were individually dissected, and internal contents were tested for Rickettsia tsutsugamushi organisms by means of indirect FA test, and each exoskeleton was mounted on slide for identification. Among 4,142 chiggers collected from 48 Apodemus agrarius at nine different localities during the period of July-November, 1989, 990 chiggers of 10 species of Trombiculidae were dissected and tested. Rickettsiae were confirmed in two Leptotrombidium pallidum larvae out of 447 tested, giving 0.4% of the infection rate. The chiggers of the other species tested were found negative.

Animals↗
PubMed1991

Epidemiological studies on host animals of tsutsugamushi disease in Korea.

Epidemiological studies on host rodents of tsutsugamushi disease were carried out during the period of July-September 1990 at nine localities of central Korea. Among total 111 wild rodents trapped by the modified Sherman live traps, 103 were Apodemus agrarius (92.8%), seven were Crocidura lasiura (6.3%) and one was Microtus fortis (0.9%), showing 24.0% of trapping rate in winter, 11.7% in spring, 11.2% in summer and 12.0% in autumn. Out of 103 A. agrarius 84 were parasitized by chiggers, showing 81.6% of the infestation rate and 43.0 of the chigger index. The antibody positive rate of A. agrarius sera to Rickettsia tsutsugamushi was significantly variable by locality, being in the range of 0-78.6%. The seasonal change of the antibody positive rate at Dorai 5-ri, Goyang-gun was 75.8% in average during November-March, decreased to 30.3% in April and further decreased to 13.3% in average during May-August. Among 33 antibody positives, 31 were Karp strain and two were Gilliam. Seven Crocidura lasiura sera showed all negative. R. tsutsugamushi organisms were isolated from three A. agrarius out of 94 mice tested, showing 3.2% of the infection rate.

Animals↗
PubMed1990

A historical review and prospects of medical entomology research in Korea.

Research activities of medical entomology in Korea can briefly be divided into three periods. During the first period (1910-1959), medical entomology research was initiated by Japanese workers, and then by U.S. Army Medical Unit personnels and a few Korean pioneers, who greatly contributed to establishing a foundation for medical entomology in Korea. During the second period (1960-1979), research activities were intensively carried out by the entomology team of the Central Malaria Eradication Service and staffs of the Division of Medical Entomology, National Institute of Health, who collaborated with WHO-Vector Ecology and Control Research Unit. During the third period (1980-present), studies were expanded to different research laboratories, such as Departments of Biology in College of Natural Sciences and Departments of Parasitology or others in Medical Schools, and study topics also became diverse. Out of 313 papers on Korean arthropods of medical importance, the majority were on mosquitoes (142 papers, 45.4%) and, next, on flies (53 papers, 16.9%). It is hard to see the future prospect of medical entomology research in Korea, since it looks pessimistic in some respects but optimistic in others. Korean medical entomologists may be quantitatively lacking, but not qualitatively behind.

Entomology↗
PubMed1989

[Trombiculid mites (Acarina: Trombiculidae) from Apodemus agrarius coreae caught at Pochun-gun, Gyeonggi Province and Chinhae-City, Kyongnam Province].

During October-December 1987, chigger mites infested on the striped field mice (Apodemus agrarius coreae) collected at Pochun-gun, Gyeonggi Province and Chinhae city, Kyongnam Province were identified. 1. Of 171 back-striped mice collected, chigger mites were found from 58 mice, showing 33.9% of infestation rate. 2. Total 865 chigger mites collected were classified into seven species; Leptotrombidium pallidum (4.3%), L. palpale(23.0%), L. orientalis(20.2), L. zetum(19.0%). Neotrombicula tamiyai(32.9), N. japonica(0.2%) and Euschongastia koreaensis(0.3%). Though the most dominant species in number was N. tamiyai(32.9% of the total), this species was collected at very limited locality and for a short period. Therefore, most common species in Korea seems to be L. palpale which was found at all localities throughout the whole survey period. L. pallidum which is known as the vector species of tsutsugamushi disease in Korea was collected in a very low number(4.3% of the total chiggers collected). 3. The number of chigger mites infested on a host animal showed great variations from one chigger up to 207 chiggers. The present study has shown that there may be other Leptotrombidium species mite(s) for the vector and host of tsutsugamushi disease in Korea.

Animals↗
PubMed1989

[The prevalence of head louse infestation among urban and rural children in Korea].

The prevalence of head louse (Pediculus hamanus var. capitis) infestation in preschool and school children in 9 urban and 8 rural areas of Korea, was investigated. Of 11,865 children who were examined for head lice and nits, 2,900(24.4%) were found infested. The over-all infestation rate of rural children, 58.9%, was higher than that of urban children, 14.4%. There also existed significant differences in the infestation rate among various regions of urban as well as rural areas. Females were more infested than males. But there was no differences in infestation rate in either sex of preschool age. The infestation rate increased gradually from the age of 6, reached a plateau between 9-12 years of age and thereafter slowly decreased. The infestation rate of an orphanage children was higher than that of general childhood population. Health education and mass-delousing attempt are urgently required to lower such a high prevalence of head louse infestation in Korea.

Adolescent↗
PubMed1988

Malaria in Korea.

Malaria was steadily decreasing in Korea except in certain counties of the mountainous and hilly areas, in the 1960s. Judging from the present epidemiological, social and economic conditions, it can be said with confidence that malaria with "unstable" characteristic in the Republic of Korea has already been disappeared. No doubt, the causes of the disappearance of malaria are complex. Certainly improved living conditions and life style; better medical and educational facilities in the wake of a rapid economic development could all have some role. On the other hand, the disappearance of malaria without large scale control operations could be ascribed to the two main factors: one is malaria case detection and simultaneous drug therapy available through the nation-wide passive case detection network during the 1960s and the other is rapidly improved farming practices begun in 1970s, which resulted in the use of a huge quantity of pesticides and other chemicals for agriculture, which, in turn, might affect local anopheline vectors which were originally not effective ones any way.

Humans↗
PubMed1973

Aerial applications of ultra-low-volume insecticides to control the vector of Japanese encephalitis in Korea.

As a suitable emergency measure to arrest epidemics of Japanese encephalitis in Korea, the ultra-low-volume method of spraying insecticide to control the mosquito vector Culex tritaeniorhynchus has been tested in 2 successive years over a 16-km (2) area, utilizing a large fixed-wing aircraft. Malathion concentrate applied at 0.36 litres/ha gave insufficient control of the parous (infective) females, and no reduction in total numbers of this species. Fenitrothion concentrate applied at 0.45 litres/ha resulted in a 77-87% reduction in total numbers and an 87-98% reduction in parous females over a 4-day period.

Aircraft↗