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Anti-inflammatory Activity of Sargassum micracanthum Water Extract (잔가시 물 추출물의 항염증 효과)

  • Jeong, Da Hyun;Kang, Bo Kyeong;Kim, Koth Bong Woo Ri;Kim, Min Ji;Ahn, Dong Hyun
    • Journal of Applied Biological Chemistry
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    • v.57 no.3
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    • pp.227-234
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    • 2014
  • The anti-inflammatory effect of Sargassum micracanthum water extract (SMWE) was investigated using lipopolysaccharide (LPS)-induced inflammatory response in this study. The murine macrophage cell line RAW 264.7 cells were used and MTT assay was performed to measure the cell proliferation ability. The secretion of nitric oxide (NO), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-6 (IL-6), and IL-$1{\beta}$ was measured in LPS-induced RAW 264.7 cells by ELISA. The expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and nuclear transcription factor-kappa B p65 protein was studied by immunoblotting. The Balb/c mice were used for an acute toxicity test, and imprinting control region mice were purchased to evaluate a croton oil-induced ear edema. As a result, there was no cytotoxicity in the macrophage proliferation treated with SMWE compared to the control. NO levels decreased with increasing concentration of SMWE and were inhibited over 50%. Moreover, the secretion of IL-6, TNF-${\alpha}$, and IL-$1{\beta}$ was suppressed in a dose-dependent manner, especially, IL-$1{\beta}$ inhibition activity was over 50% at 50 ${mu}g$/mL. The formation of ear edema of mice was reduced at the highest dose tested compared to that in the control. Moreover, in acute toxicity test, no moralities occurred in mice administered 5,000 mg/kg body weight of SMWE over 2 weeks observation period. These results suggested that SMWE may have significant effects on inflammatory factors and be potential anti-inflammatory therapeutic materials.

Clinical Significance of Immature Reticulocyte Fraction and Reticulocyte Cellular Indices in Pediatric Anemia Patients (망상적혈구 지수 및 미성숙망상적혈구 분획의 소아 빈혈에서의 임상적 의의)

  • Seo, Young;Jung, Hye Lim;Shim, Jae Won;Kim, Deok Su;Shim, Jeong Yeon;Park, Moon Soo
    • Clinical and Experimental Pediatrics
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    • v.48 no.3
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    • pp.284-291
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    • 2005
  • Purpose : Flow cytometric automated reticulocyte analysis is a superior method to manual reticulocyte counting, with respect to precision and sensitivity. Furthermore, flow cytometric analysis is able to measure immature reticulocyte fraction(IRF) and reticulocyte cellular indices(RCI : cell hemoglobin content : CHr, mean cell volume : MCVr, cell hemoglobin concentration mean : CHCMr, distribytion width : RDWr, HDWr, CHDWr). In this study, we investigated the mean values and clinical significances of IRF and RCI in healthy children and pediatric anemia patients. Methods : IRF and RCI were measured with an automated blood cell analyzer, ADVIA 120(Bayer, USA) using oxazine 750 dye, in 57 healthy children and 61 children with anemia. The anemia group consisted of 27 iron deficiency anemia(IDA) patients and 34 patients with anemia associated with acute infection(AAI). We compared the mean values of IRF and RCI in the control group classified according to age, between anemia groups and the control group, and between the IDA group and the AAI group. Results : For the normal control group, the mean values of IRF, CHr, MCVr and HDWr were higher in neonates when compared to older children. The mean values of IRF and RDWr were significantly higher, and the mean values of CHr and CHCMr were significantly lower in the IDA group when compared to the control group. The mean value of IRF was significantly higher, and the mean value of CHDWr was significantly lower in the AAI group when compared to the control group. The mean values of IRF, CHr and CHCMr were significantly lower in the IDA group when compared to the AAI group. Conclusion : We could determine the normal mean values of IRF and RCI in healthy children classified according to age for understanding of hematopoietic response differences according to age. The evaluation of IRF and RCI by automated reticulocyte analyzer seemed to be accurate and clinically useful for the early diagnosis of anemia and the differentiation of IDA from AAI.

Field Survey on Smart Greenhouse (스마트 온실의 현장조사 분석)

  • Lee, Jong Goo;Jeong, Young Kyun;Yun, Sung Wook;Choi, Man Kwon;Kim, Hyeon Tae;Yoon, Yong Cheol
    • Journal of Bio-Environment Control
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    • v.27 no.2
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    • pp.166-172
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    • 2018
  • This study set out to conduct a field survey with smart greenhouse-based farms in seven types to figure out the actual state of smart greenhouses distributed across the nation before selecting a system to implement an optimal greenhouse environment and doing a research on higher productivity based on data related to crop growth, development, and environment. The findings show that the farms were close to an intelligent or advanced smart farm, given the main purposes of leading cases across the smart farm types found in the field. As for the age of farmers, those who were in their forties and sixties accounted for the biggest percentage, but those who were in their fifties or younger ran 21 farms that accounted for approximately 70.0%. The biggest number of farmers had a cultivation career of ten years or less. As for the greenhouse type, the 1-2W type accounted for 50.0%, and the multispan type accounted for 80.0% at 24 farms. As for crops they cultivated, only three farms cultivated flowers with the remaining farms growing only fruit vegetables, of which the tomato and paprika accounted for approximately 63.6%. As for control systems, approximately 77.4% (24 farms) used a domestic control system. As for the control method of a control system, three farms regulated temperature and humidity only with a control panel with the remaining farms adopting a digital control method to combine a panel with a computer. There were total nine environmental factors to measure and control including temperature. While all the surveyed farms measured temperature, the number of farms installing a ventilation or air flow fan or measuring the concentration of carbon dioxide was relatively small. As for a heating system, 46.7% of the farms used an electric boiler. In addition, hot water boilers, heat pumps, and lamp oil boilers were used. As for investment into a control system, there was a difference in the investment scale among the farms from 10 million won to 100 million won. As for difficulties with greenhouse management, the farmers complained about difficulties with using a smart phone and digital control system due to their old age and the utter absence of education and materials about smart greenhouse management. Those difficulties were followed by high fees paid to a consultant and system malfunction in the order.

STRESS DISTRIBUTION IN ESTHETIC ORTHODONTIC BRACKETS : AN ANALYSIS USING THE FINITE ELEMENT METHOD (유한요소 분석을 통한 심미적 교정 브라켓의 응력 및 구조분석에 관한 연구)

  • Lee, Won-You;An, Ju-Sam;Park, Young-Cheol;Park, Myeong-Kyun;Sohn, Hong-Bum;Jeong, Si-Dong
    • The korean journal of orthodontics
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    • v.28 no.1 s.66
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    • pp.43-49
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    • 1998
  • The aim of this study were to measure and compare the stress level on three type brackets and each other material (stainless steel, ceramic) with tipping and torquing forces by using the finite element analysis and to design biomechanically favorable brackets. For this study, three kinds of brackets were selected(A:Transcend-RMO, B:Signature-Unitek, C:PAW: plain archwire appliance-applied for a patent in Yonsei Udiversity). The slot size of bracket was 0.022inch and the size of archwire was 0.0175x0.025inch and taper shaped archwire was used in PAW. Loading force in tipping was 4.27N and torquing force was 32.858N applied by archwire torsion with 19.7degree and 11.3 degree in C type bracket. The conclusions were that (1) The finite element method proved to be a useful tool in the stress analysis of orthodontic bracket subjected to various forces. (2) With tipping, the stresses were concentrated at the gingival wall of the wire slot where it meets the mesial bracket surface and the incisal wall of the wire slot where it meets the distal bracket surface and with torquing, the stresses were concentrated at the junction of the gingival or incisal wall and base of the slot. (3) The maximum stress value was higher in torquing force than tipping force and therefore it is desirable to design on the basis of torquing force. (4) It was considered that the change in material might be affect on the diminish of stress value in the place of stess concentration. (5) The maximum stress value was highest on PAW bracket when the tipping and torquing force was applied and therefore it would be desirable to use mechanically favorable material on PAW bracket.

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The Effects of Sibjeondaebotanggamibang on the Treating of Wound (십전대보탕가미방(十全大補湯加味方)의 창상(創傷) 치유(治癒) 효과(效果))

  • Jung, Hoon;Lee, Hyun-Jae;Kim, Binnara;Lee, Chi-Ho;Lee, Eun-Jung;Heo, Dong-Seok;Oh, Min-Seok
    • Journal of Korean Medicine Rehabilitation
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    • v.24 no.3
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    • pp.51-69
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    • 2014
  • Objectives This study was aimed to investigate the effects of Sibjeondaebotanggamibang (SJT) on the wound-induced rats. Methods It was observed the effects of anti-oxidation and anti-inflammation by using of lipopolysaccharide (LPS)-treated RAW 264.7 cells. For the observing on SJT anti-oxidation, it needed to mesure the total amount of polyphenol, DPPH scavenging ability, ABTS scavenging ability and the value of ROS production. In order to observe on the anti-inflammation of SJT, it was mesured the value of No and Cytokine (TNF-${\alpha}$, IL-$1{\beta}$, IL-6). It needed to make a scar (around $2{\times}2cm^2$) on the top of the fascia in the back of the rats and then the rats were divided into 4 groups (n=6). Control group was not treated at all, whereas SJ group was orally medicated SJT, Terra group was per-cutaneously applied Terramycin, and SJ+Terra group was both orally medicated SJT and percutaneously applied Terramycin per day for three weeks. The size of wound was measured with Digimatic Caliper and the blood samples (WBC, neutrophil, monocyte, lymphocyte) were analyzed using Minos-ST, which were collected by cardiac puncture. The effect on inflammatory cytokine (TNF-${\alpha}$, IL-$1{\beta}$, IL-6), immunological cells in synovial fluid was measured. To measure the wound factor expressed by wounded skin sample, we extracted RNA and to investigate MMP-1,2,9 we used RT-PCR. For performing histopathological examinations, we paralyzed the rats by ether, and extracted wounded skin tissues, which were measured by H & E, and monitored on the optical microscope. Results 1. DPPH and ABTS scavenging activity of SJT was increased concentration-dependantly, and ROS scavenging activity was significantly increased (10, $100{\mu}g/ml$). 2. NO production was significantly reduced in SJT treated cells ($100{\mu}g/ml$), both TNF-${\alpha}$ and IL-6 in SJT treated cells (1, 10, $100{\mu}g/ml$), and IL-$1{\beta}$ in SJT treated cells (1, $100{\mu}g/ml$). 1. The size of wound was significantly decreasing in SJ group, Terra group, SJ+Terra group. 2. WBC was significantly reduced in SJ and SJ+Terra group, monocyte in SJ+Terra group. Neutrophil was also reduced in SJ, SJ+Terra group but meaningless. 3. TNF-${\alpha}$ and IL-6 were significantly reduced in SJ group, Terra group, SJ+Terra group, and IL-$1{\beta}$ in SJ+Terra group. 4. mRNA expression in MMP-1 was significantly reduced in SJ group. 5. Collegan production and chronic inflammation were significantly decreased in SJ group, Terra group, SJ+Terra groups. Re-epithelization on the skin in Terra group, SJ+Terra groups was decreased. Conclusions According to this in vitro experiment, Sibjeondaebotanggamibang (SJT) has the effects of anti-oxidative and anti-inflammatory. By in vivo experiment, SJT has the effects of anti-inflammatory. Moreover, the progress of recovery was found visually, heamatologically, genetically and histopathologically. In conclusion, it could be thought that SJT has effect on the treating of wound.

Comparison between the method of the measurement 25 Vitamin D3 (25 Vitamin D3 측정에 있어서 화학발광미세입자 측정법과 화학발광면역 측정법 간의 비교 및 고찰)

  • Kim, dae-won;Lee, jung-hee;Jung, an-na;Seo, so-yoen
    • The Korean Journal of Nuclear Medicine Technology
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    • v.19 no.2
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    • pp.112-114
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    • 2015
  • Purpose Vitamin D to Anti- Rickets both steroid compounds showing activity, By acting on bone tissue secretary and the key to maintain serum Ca homeostasis. The blood level of vitamin D is the largest in D3 that the concentration of the metabolite is reflected in the holding state of vitamin D in vivo. Sunlight to change the 7-dehydrocholesterol in the skin and through the skin to D3, In the liver in combination with the D2 and D3 D4 changes. The Radioimmunoassay(RIA) method is measuring the D 3, the sensitivity can be measured also difficult trace substance to measure the normal test because it is very sensitive, but recently, a check is possible, for the Total D3 in Chemimicroparticle immunoassay(CMIA) or Chemiluminescent immunoassay(CLIA) measuring using microparticle RIA and CMIA(Architect i2000SR) / use the CLIA(DXI-800) method to compare and evaluate the correlation between the tests in the same test items. Materials and Methods Commissioned from January 2014 to March 2015 patients were enrolled in a total of 273 people. 29 out of 273 people conducted by RIA were compared with CMIA, 244 patients were compared with CLIA. Using reagents and equipment were used RIA(Diasource), CMIA(Architect i2000SR, Abbott Diagnostics) / CLIA( Unicel DXi-800, Beckman coulter). Results Correlation of the RIA and CLIA was a R2 = 0.1844 (y = 0.7303x + 3.9005), and the correlation of RIA CMIA is R2 = 0.2762 (y = 0.8862x + 4.56) respectively. (According to statistics, during the same period RIA is Deficiency 4.31%, Insufficiency 90.53%, Sufficiency 5.16%, was Excess 0%, CLIA / CMIA is Deficiency 17.02%, Insufficiency 75.91%, Sufficiency 7.03%, indicating the distribution of 0.03 % Excess) Conclusion Serum vitamin D and parathyroid hormone that show an inverse relationship, the level above which are not parathyroid hormone and vitamin D reduced the increase. The density is different for each study, at most 20 is reported to be the maximum between 30 ng / ml. In Korea it requires a proposed standard of vitamin D deficiency, reference to the WHO lack the case more than 10ng/ml, 20ng/ml and defined by the lack of, if not more than, the IOM, but looking at 12ng/ml or less to the normal to lack, at least 20ng/ml, the reference do not match the deficit under 20ng/ml, 21-29ng/ml relative lack between, was also defined as a sufficient condition for more than 30ng/ml. Although not statistically is between RIA and CLIA two ways to vitamin D levels change according to season match, when seasonally seen in summer as commonly known (April to September), winter (October to March) relative to the increase measured than it was found. Finally, the study on the correlation between the two methods have been expected to result in a consistent and apply the same view high reference value on the graph is difficult. However, there may be differences between the test equipment and methods, and could be especially the case of RIA method using an organic solvent is difficult to compare different methods and correlated view similar trend in vitamin D deficiency and quarterly aspect ratio.

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Development of an Efficient Screening Method for Resistance of Chili Pepper Plants to Meloidogyne incognita (뿌리혹선충 Meloidogyne incognita에 대한 저항성 고추를 선발하기 위한 효율적인 검정법 확립)

  • Hwang, Sung Min;Jang, Kyoung Soo;Choi, Yong Ho;Choi, Gyung Ja
    • Horticultural Science & Technology
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    • v.34 no.2
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    • pp.282-293
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    • 2016
  • Root-knot nematodes (Meloidogyne spp.) are major plant pathogens that cause reductions in yield and quality of several solanaceous crops, including pepper (Capsicum spp.). These losses can be averted through planting of resistant cultivars. Plants are defined as resistant when they suppress nematode reproduction. In this study, the resistance degrees of 102 commercial cultivars of chili pepper (Capsicum annuum) to a root-knot nematode, Meloidogyne incognita, were evaluated by comparing the number of egg masses on their roots to those of 'PR huimangchan', a highly susceptible cultivar that exhibited the most egg masses of the chili pepper cultivars evaluated. Among these cultivars, forty-four (43.1%) showed resistance to M. incognita and eighteen (17.6%) were moderately resistant. The other cultivars (39.3%) were determined to be susceptible. For further study, six chili pepper cultivars (i.e., Gangryeokjosenggeon, Shinsegae, Muhanjilju, PR Bulrocho, PR Huimangchan, and Jjang) with different levels of resistance to the nematode were selected. Changes in resistance of the six cultivars under several conditions, such as inoculum concentration, plant growth stage, and cultivation period after transplanting were investigated. We found that an efficient screening method for resistance of chili pepper to M. incognita is to transplant the chili pepper seedlings 7 days before inoculation, to inoculate 28-day-old plants with M. incognita by loading 5,000 eggs per plant into the pot of soil, to cultivate the plants in a greenhouse ($25{\pm}5^{\circ}C$) for 45-60 days, to measure the number of egg masses on roots of the seedlings, and then to determine the resistance response of the plants by comparing the number of egg masses on the roots with a reference-susceptible cultivar 'PR huimangchan'.

Relationship between Monounsaturated Fatty Acid Composition and Stearoyl-CoA Desaturase mRNA Level in Hanwoo Liver and Loin Muscle (한우 간 및 등심 조직에서 불포화지방산의 조성비율과 Stearoyl-CoA Desaturase mRNA의 발현 양상)

  • Lee, S.H.;Yoon, D.H.;Hwang, S.H.;Cheong, E.Y.;Kim, O.H.;Lee, C.S.
    • Journal of Animal Science and Technology
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    • v.46 no.1
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    • pp.7-14
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    • 2004
  • The Stearoyl-CoA Desaturase(SCD) is a key enzyme, which converting palmitic acid(16:0) and stearic acid (18:0) to pahnitoleic acid(16:1) and oleic acid(l8:1), respectively. The concentration of oleic acid(18:1) in meat of beef cattle could influence both palatability and perception of meat. This experiment has conducted to determine relationship between the compositions of monounsaturated fatty acids and the SCD mRNA level in bovine liver and loin muscle tissue. The compositions of palmitoleic acid(16:1) and oleic acid(18:1) in loin muscle were 5% and 46% of total lipid and in liver were 2% and 20% of total lipid, respectively. On the other hand, the compositions of palmitic acid(16:0) and stearic acid(18:0) in loin muscle were 25% and 45% of total lipid and in liver were 14% and 43% of total lipid, respectively. The ratio of monounsaturated to saturated fatty acids(the desaturation index) was used as a measure of SCD activity in tissues. The average desaturation index in loin muscle was higher about 3.6-fold than that in liver. The desaturation index of oleate/stearate and palmitoleatelpalmitate in loin muscle were higher 8-fold and 1.8-fold than those in liver, respectively, showing that the substrate specificity of SCD enzyme was very different between liver and muscle tissues. To determine whether the composition of monounsaturated fatty acids in liver and muscle are dependent on SCD expression, SCD mRNA level was examined by RT-PCR analysis. The SCD mRNA level in loin muscle was higher about 3-fold than that in liver. Thus, the quantitative relationship between the desaturation index of fatty acid and SCD mRNA was observed in liver and muscle. The difference in the compositions of monounsaturated fatty acids between bovine liver and muscle tissues may be due to different level of Stearoyl-CoA Desaturase mRNA.

Nitrogen Removal Via Sediment Denitrification and Its Seasonal Variations in Major Estuaries of South Coast of Korean Peninsula (남해안 주요 하구 갯벌 퇴적물의 탈질소화를 통한 질소 영양염 제거)

  • Heo, Nak-Won;Lee, Ji-Young;Choi, Jae-Ung;An, Soon-Mo
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.16 no.2
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    • pp.81-96
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    • 2011
  • Sediment oxygen demand(SOD) and denitrification rates were measured in four major estuaries(Suncheon Bay, Seomjin river estuary, Goseong stream estuary and Masan Bay) in south coast of Korean peninsula from March of 2009 to May 2010 to estimate organic matter cleaning capacity. SOD was estimated from the temporal dissolved oxygen concentration change and isotopic pairing technique was employed to measure denitrification. Sediment oxygen demand(SOD) was ranged from -5.1 to 24.6 mmole $O_2m^{-2}d^{-1}$ and denitrification rate was ranged from 0.0 to 3.9 mmole $N_2m^{-2}d^{-1}$in the study area. SOD was the highest in Masan Bay(-2.2 to 19.2, average = 10.2 mmole $O_2m^{-2}d^{-1}$) and Suncheon, Goseong, Tae-an and Seomjin followed. Denitrification was also the highest in Masn Bay(0.0 to 3.9, average = 1.0 mmole $N_2m^{-2}d^{-1}$) and Goseong, Seomjin, Suncheon and Taean followed. The effect of benthic photosynthesis by microphytobenthos on denitrification was evident in some season of Tae-an, Seomjin, and Masn Bay. The increased oxygen level produced by photosynthesis stimulated nitrification without severe adverse effect on denitrification and, as a result, coupled nitrification and denitrification was enhanced in these areas. A difference of seasonal patterns of denitrification at each site depended on relative importance of denitrification on different nitrate source($D_w$: nitrate from water column and $D_n$: nitrated produced during nitrification). Denitrification was maximum during spring in Goseong, Suncheon and Masan Bay. On the contrary, denitrification was the highest during summer in Tae-an and Seomjin estuary.

Epidemiological Studios on Clonorchis sinensis Infection along the Nam-river in Gyeongnam Province, Korea (남강유역 간흡충감염의 역학적 조사연구)

  • 배경훈;안영겸
    • Parasites, Hosts and Diseases
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    • v.21 no.2
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    • pp.116-186
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    • 1983
  • An epidemiological study on Clonorchis sinensis infection along the Nam-river (total length ; 186km) flowing in Gyeongsang-nam-do, southern part of Korea, was carried out. Formalin-ether concentration technique and Stoll's egg counting method were employed to figure out the prevalence of C. sinensis infection. For the detection of cercariae from Parafossarulus sp., the snail host of C. sinensis, each snail was placed in aerated tap water, and examined for expelled cercariae. For observing the metacercariae the fresh water fish favorably eaten in raw conditions wore prepared by means of pressing the muscles between two slide glasses and/or by digesting them with artificial gastric juice. The fresh water fish were fed to the rabbits to get the worms and to identify the morphology of adult C. sinensis. The results are summarized as follows: 1. Overall Prevalence of C. sinensis infection was 38.75 from 5,291 examinees; 44.15 (1,408 out of 3,196) in male and 30.4% (637 out of 2,095) in female. 2. The prevalence rates were 42.0% at the upper stream, 41.2% around the vicinity of Jinyanglake, 34.2% at Jinju city, 34.2% at middle stream and 40.3% at down stream regions, respectively. 3. By age, the highest positive rate (53.4∼54.3%) was observed in 30 to 59 years of age. In this age group, the rate in males was 59.7∼62.2%, and in females 42.2∼44.4%, In the age group of less than 19 years it was 7.5∼20.9%. 4. By social strata, the positive rate was 16.5% in the primary school children, 22.6% in school students, 46.2% in teachers and local officers and 49.6% in the general inhabitants. 5. The quantitative examinations with the stool collected from clonorchiasis cases revealed that the light infection (less than 4,000/EPG) was 53.6%, moderate infection (4,001∼10,000 /EPG) 30.3% and heavy infection (more than 10,001/EPG) 16.1%, respectively. More than half of total cases examined were light infection, and 73.2% of female examinees were lightly infected with this cuke. 6. The average value of EPG was 4,963 (male, 6,057; female, 2,557 and the highest value was obtained from the age group of 30 to 59 years (5,240∼6,454). 7. The prevalence of Metagonimus yokogawai infection in humans was 5.5%, and 89.8% of metagonimiasis cases wore double-infected arith C. sinensis. The highest prevalence rate was observed in Jinju city (11.2%). 8. Total of 5,005 Parafossarulus sp., the snail intermediate host of C. sinensis, were examined for the detection of cercariae. The cercarial expulsion rate was 0.34%, and the snails collected in Jin-yang-lake side and in the down stream expelled mainly the cercariae of C, sinensis. 9. About 788 cercariaejday (range: 127∼1,503) were expelled daily from a snail naturally infected with C. sinensis. The snails which released more than 1,000 cercariae/day were 30.8% out of total collected. A snail uniquely released 5,840 cercariae/day in this study. 10. The other trematode cercariae besides C. sinensis were also detected, and the rates out of total snails were the cercariae of Losogenes liberum 6.71%, Cyathocotyle orientalis 0.26%, Notocotylus attenuatus 2.52% and Mucobucaris 0.54%, 11. Ten out of 18 species of fresh water fish caught along the river harbored the metacercariae of C, sinensis. The highest rate of metacercarial infection in fish was detected in Pseudorasbora larva (85.9%). The fish mainly eaten by the inhabitants along the Nam-river, and the metacercarial infection rates were: Zacco platypus 8.0%, Hemibarbus sp. 18.2∼26.7%, Gnathepcgcn sp. 37.5%, Ischikauia steenackeri 42.9% and Pseudogobio esocinus 16.7%. 12. Out of 36 P. larva, the number of metacercariae were about 109 (ranEe; 18∼446) per fish and 27 per gram of flesh. The fish caught in spring harbored the highest number of metacercariae. As indicated above, the prevalence of C. sinensis infection in the inhabitants residing around the Nam-river was relatively high. The farther toward the upper stream areas, the higher was the positive rate of C. sinensis infection, and most of clonorchiasis cases were lightly infected. The snail hosts of C. sinensis distributed all around the Nam-river. Several species of freshwater fish were infected with the metacercariae of C. sinensis and the infection rates were relatively high. To prevent C. sinensis infection in the endemic areas, the effective health education system is suggested as a control measure, although mass treatment is also expected to be useful, using chemotherapeutic agents such as "praziquantel", a recently developed anthelminthic for C. sinensis inftraction.

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