• Parasites, Hosts and Diseases
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• v.28 no.2
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• pp.101-108
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• 1990

Surgically collected cystic fluid of Taenia solium metacestodes from patients of intracranial cystic lesion were compared in their protein composition with those from naturally infected pigs in Cheju Do, Korea and Ecuador. In non-denaturing discontinuous-polyacryla aide gel electrophoresis (disc-PAGE) , no discernible differences were recognized in banding patterns between the cystic fluids from Cheju Do and Ecuador, and between the cystic quids from pigs and human lesions except wider bands that corresponded to human albumin and T-globulin (in 4 of 9 patients). In reducing SDS-PAGE, bands in the cystic Ruid from Ecuador showed the same banding pattern with that from Cheju Do but two bands of 21 and 17 kDa were stained darker. Cystic quids (rom patients revealed the same protein compositions of the major protein bands of 94, 64, 15, 10 and 7 kDa as in the cystic fluid of pig origin, but human albumin (66 kDa), heavy and light chains of gamma globulin (55 and 22.5 kDa) were contaminated in 4 of 9 cystic fluids. Human CSF proteins seem to have been contaminated during cystic ftuid collection. In any cystic quid from patients, the majcr Protein component was 150 kDa which was subdivided into 15, 10 and 7 kDa in reducing SDS-PAGE.

• Parasites, Hosts and Diseases
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• v.31 no.3
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• pp.207-214
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• 1993

This study was conducted to evaluate the current endemicity and the transition mode of the Clonorchis infection in Sanchong-gun Kyongsangnam-do. The areas of investigation, villages and schools surveyed, method and techniques used in this study were the same as in 1984. The egg positive rate of clonorchiasis in the general population of Sanchong-gun was 37.6% out of 837 exanuned persons. In the schoolchildren. the rate was 9.7% out of 145 persons examined. In the Intensity of the infEction among the cases. the mean EPG (Egg Per gram of feces) in the inhabitants and schoolchildren were 3, 310 (male 4, 221, female 1, 978) and 711 tamale 620. female 8331, respectively. Of the inhabitants with clonorchiasis, the cases of light infection (EPG < 1, 000) and moderate infection (1.000 < EPG < 10, 000) were 93.9%. The proportion with experience of eating raw freshwater-fish was 90.5% among the infecters. Out of 138 Inhabitants examined in both 1984 and 1992, the number of the positives by both examinations was 31 (22.5%), positive to negative conversion was 35 (25.4%), negative to positive conversion was 22(15.9%). The present results reveal that there are no chanties of the e99 Positive rate of clonorchiasis among inhabitants in Sanchong and the eating habit of raw freshwater-fish persists there. In this community, the eating habit Is the most important problem to be solved for control of this endemic diease.

• Parasites, Hosts and Diseases
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• v.28 no.4
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• pp.197-206
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• 1990

Various conditions of cultures were performed to investigate the role of tight junctions formed between adjacent MDCK cells on the entry of Toxoplasma. When MDCK cells were cocultured with excess number of Toxoplasma at the seeding density of 1×105, 3×105, and 5×105 cells/ml for 4 days, the number of intracellular parasites decreased rapidly as the host cells reached saturation density, i.e., the formation of tight junctions. When the concentration of calcium in the media (1.8 mM in general) was shifted to $5{\mu}M$ that resulted in the elimination of tight junction, the penetration of Toxoplasma increased about 2-fold(p<0.05) in the saturated culture, while that of non-saturated culture decreased by half. Trypsin-EDTA which was treated to conquer the tight junctions of saturated culture favored the entry of Toxoplasma about 2.5-fold(P<0.05) compared to the non-treated, while that of non- saturated culture decreased to about one fifth. It was suggested that the tight junctions of epithelial cells play a role as a barrier for the entry of Toxoplasma and Toxoplasma penetrate into hoot cells through membrane structure-specific, i.e., certain kind of receptors present on the basolateral rather than apical surface of MDCK cells.

• Parasites, Hosts and Diseases
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• v.27 no.2
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• pp.119-130
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• 1989

An experimental pathological study was performed to observe the effect of prasiquantel treat- ment on the pulmonary lesions of the rat lung cuke, Paragonimus ilektsuenensis. The metacercariae were obtained from the freshwater crab, Sesarma dehaani, and 40 rats (wistar) were fed each with 10 metacercariae. On 20 rats prasiquantel treatment ($100mg/kg/day{\times}5$ days) was done at 5 weeks after the infection while remaining 20 rats were kept untreated for use as controls. The drug.treated rats and the untreated ones were sacrificed 3, 7, 14, 21 or 28 days later for the observation of lung pathology. The rats infected with P. iloktsuenensis showed remarkable pulmonary changes; gross features of hemorrhagic and nodular worm capsules protruded on to the surface of the lung, and histologically local atelectasis, inflammatory cell infiltration, and egg granuloma around the worm capsules each containing one or two worms. Praziquantel treatment of the rats was shorn to be highly effective in killing the worms and to lead them to degenerate, as early as in 3 days post-treatment. Almost all worms in the lung were dead and absorbed by the host cells in 21 days post-treatment, except a few living ones seen in a rat of 14-day post-treatment group. In most of the rats treated the pulmonary lesions showed the signs of resolution; regression of worm capsules with mummification of worms, decrease of inflammatory cell infiltration, improvement in the degree of atelectasis, and decreases in the frequency and size of the egg granuloma. From the results it is concluded that prasiquantel is highly effective for the treatment of rat P. iloktsuenensis infection in the lung, not only by its direct killing effect of the worms but also due to the excellent resolution capacity of the pulmonary tissues.

• Parasites, Hosts and Diseases
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• v.27 no.2
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• pp.79-86
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• 1989

A pathogenic free-living amoeba, Naegleria fowleri, causes primary amoebic meningoencephalitis to human and experimental animals. This infection is rare, but the mortality is very high. Nowadays, drug treatment or active immunization of human or mice are being tried with partial effectiveness. This study shows passive immunization effect by transfer of immunized spleen cells, serum, or milk from immunized mother in mouse experimental model. Young BALB/c mice were immunized intraperitoneally with $2~3{\times}10^{6}$ trophozoites of N. fowleri, and spleen cells and sera were collected for injection to recipient mice. There were seven transfer groups, i.e., immunized mouse serum, spleen cells, serum and spleen cells, normal mouse serum, spleen cells, serum and spleen cells, and control group. Three days later, BALB/c mice were inoculated with $1{\times}10^{4}$ trophozoites of N. fowleri intranasally. After infection, decreased mortality ana prolonged survival time of mice were noted in immunized Bloops compared with non.immuniBed control group. The groups Injected with immunized spleen cells or normal serum shewed lower moltality than that of controls bult showed no changes of Serum IgG level. The groups injected with immunized serum or normal spleen cells showed increased serum IgG level after immunization but hundred percent mortality was observed. Mother mice were ifnfnunised increperitqneeliy with $2~3{\times}10^{6}$ trephozoites of N. fowleri at the end of pregnancy and weaning Period. Soon after the delivery, Jitters born of non-immunszed mother were matched with immunized mother for feeding immune milk. After three weeks, the litters were infected with $1{\times}10^{4}$ trophozeites of N. fowleri or sacrificed for serum collection to measure the IgG levels. The results show that anti-JV. fowleri IgG from mother was transferred to litter through milk but this IgG did not inauence the mortality or survival time of the infected mice.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.12
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• pp.1105-1112
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• 2009

Antibiotics are biologically active substances and commonly used for therapeutic treatment of infectious disease in humans and for treating and protecting the health of animals. In recent years, antibiotics have attracted worldwide attention because of their side effects on the environment. Consequently, efforts have been made to monitor the residual of antibiotics in the environment. This study tested the mobility of tetracyclines and sulfonamides in soil and leachate through column experiments. The three tetracycline antibiotics showed higher mass recovery rates in all kinds of soils(28.00~44.11%) than in leachate(10.54~27.43%). This seems attributable to the high adsorption coefficient values($K_d$) of tetracyclines representing strong and active adsorbability to organic and mineral phases in soil, ending up relatively small amount being detected in surface water. By contrast, the sulfonamides(sulfamethazine and sulfathiazole) showed higher mass recovery rates in leachate(23.19~26.20%) compared to in soil(10.41~14.21%) due to lower adsorption coefficient values and higher mobility of sulfonamides, enabling easier movement to surface water through the runoff in the environment.

• Parasites, Hosts and Diseases
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• v.26 no.1
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• pp.45-54
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• 1988

To observe the clinical course and intestinal histopathology in heavy infection of Fibricola seoulensis, an experimental study was performed in mice. Clinical, experimental infection with 1, 000 metacercariae. On the 11th day after infection, the mice began to die and all of the infected mice were dead by the 16th day. The infected mice showed gradual weight loss. Occult blood was detected after the 10th day. Diarrhea accurred after the 9th day and was recognized in all of the infected mice on the 12th day. Hemoglobin and mean corpuscular hemoglobin decreased significantily after the 12th day, and mean corpuscular hemoglobin concentration decreased in all infected mice. The histopathological changes were more marked in the duodenum than in the jejunum or ileum. Major changes were villous atrophy and crypt hyperplasia, with decreased villus/crypt ratio, inflammatory cell infiltration and stromal edema. The present results suggest that the cause of death of mice heavily infected with F. seoulensis should be malnutrition and severe fluid loss due to malabsorption, together with intestinal bleeding.

• Parasites, Hosts and Diseases
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• v.34 no.2
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• pp.113-120
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• 1996

An epidemiological survey was performed to know the status of Cwptespori,mum sp. infection among the people in Seoul and Chollanam-do in 1992. One village of Chollanam-do (Hwasun-gun) which showed the highest oocyst positive rate was re-surveyed in 1995 for human infection and for cattle also. The subjected areas consisted of 8 urban villages (: dongs) of Seoul and 4 urban (: dongs) and 7 rural (: myonsl villages of Chollanam-do. A total of 3,146 fecal samples was collected randomly, and smears were made from formalin-ether sediments. They were examined for Cwptosporinium oocysts by modified acid fast staining. The overall oocyst positive rate was 79% (248/3,146), but the rate was remarkably different between Seoul and Chollanam-do, 0.5% (4/853) and 10.6% (244/2,293), respectively The average size of oocysts was 4.8 ± 0.5 by 4.2 ± 0.5 ㎛, compatible with C. pcnlum. In Chollanam-do, rural villages showed significantly higher rate (14.0%) than urban villages (3.7%). Especially the people in Iyang-myon, Hwasun- gun, a typical rural village, revealed a very high rate of 40.0% (74/185). Adults aged 51-70 years revealed the highest positive rate among all age groups. At the re-survey of the same village of Hwasun-fun in 1995, 44 (35.2%) of 125 villagers and 14 (93.3%) of IS cattle examined were positive for C. pnnpum oocysts. The results suggest that C. pnnpum is highly prevalent in rural areas of Chollanam-do, and an important source or mode of infection seems to be contaminated water or contact with the feces of infected cattle.

• Parasites, Hosts and Diseases
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• v.32 no.4
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• pp.215-222
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• 1994

The relationship between the intestinal histopathology and number and position of' intraepithelial Iymphocytes(IEL) was observed chronologically in the small intestine of rats experimentally infected wiH Metagonimw vokogawci. Fifteen Sprague-Dawley rats were orally infected each with 3,000 metacercariae, and 3 were kept uninfected for controls. Three rats each were sacrificed on the day 5, 10, 15, 24 and 70 post-infection (PI) and samples of the small intestine, 5 cm, 10 cm, 20 cia and 70 cm posterior to the pylonls were taken. The samples were processed routinely and stained with Giemsa. The intestinal histopathology was severe during the day 5-15 PI and characterized by villous atrophy, crypt hyperplasia, and decrease of villus/ciypt height ratio. After the day 24 PI, the intestinal lesions showed some tendency of recovery The number of IEL increased at the early stage of infection, but decreased thereafter to a lower level than that of controls, with progression of the pathological changes. Then, the IEL number began to increase again after the day 24 PI. In control rats, the great majority of the IEL were located at the basal region of the epithelium. During the early stage of infection, however, a considerable proportion of IEL was found to have moved to the intermediate or apical region of the epithelium. From the above results, it is suggested that the change of IEL number and position during the course of M. yokogowoi infection should be closely related to the progression and recovery of the intestinal histopathology.

• Journal of Life Science
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• v.27 no.6
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• pp.694-701
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• 2017

Mycoplasma genitalium represents the smallest genome among mono-cultivable prokaryotes. To discover and compare the orthologs (conservative genes) among M. genitalium and 14 prokaryotes that are uncultivable and have less orthologs than M. genitalium, COG (clusters of orthologous groups of protein) analyses were applied. The analyzed prokaryotes were M. genitalium, one hyperthermophilic exosymbiotic archaeon Nanoarchaeum equitans, four intracellular plant pathogenic eubacteria of Candidatus Phytoplasma genus, and nine endosymbiotic eubacteria of phloem- and xylem-feeding insects. Among 367 orthologs of M. genitalium, 284 orthologs were conservative between M. genitalium and at least one other prokaryote. All 15 prokaryotes commonly have 29 orthologs, representing the significance of proteins in life. They belong to 25 translation-related, including 22 ribosomal proteins, 3 subunits of RNA polymerase, and 1 protein-folding-related. Among the 15 prokaryotes, 40 orthologs were only found in all four Candidatus Phytoplasma. The other nine Candidatus, all endosymbionts with insects, showed only a single common COG0539 (ribosomal protein S1), representing the diversity of orthologs among them. These results might provide clues to understand conservative genes in uncultivable prokaryotes, and may be helpful in industrial areas, such as handling prokaryotes producing amino acids and antibiotics, and as precursors of organic synthesis.