• Biomedical Science Letters
• /
• v.4 no.1
• /
• pp.11-25
• /
• 1998

The HLA genes located in the short arm of chromosome 6 specify heterodimeric glycoproteins involved in the regulation of the immune response. Recently, in the elucidation of HLA polymorphism, serological and cellular typing methods have been replaced by DNA typing using polymerase chain reaction (PCR). The purpose of this study was to establish the HLA DNA typing methods and determine gene frequencies of HLA molecules in Koreans. PCR-SSP (sequence specific primers) and PCR-RFLP (restriction fragment length polymorphism) techniques were used for the analysis of HLA-A, -B, -C, DRBl genes and HLA-DQAl, DQBl, DPBl genes, respectively. The results of B-lymphoblastoid cells used for control experiment were consistent with the previous data identified in the 11th International Histocompatibility Workshop. Seventeen, 23, 16, 8, 16, 13 and 37 types of HLA-A, B, C, DQAl, DQBl, DPBl and DRBl alleles were found, respectively, in a total of unrelated 120 Korean individuals. The most frequent HLA alleles were $A^*$02 (27.0%), B$^*$40 (17.6%), Cw$^*$01 (19.2%), DQAl$^*$0301 (32.1%), DQBl$^*$0303 (12.9%), DPBl$^*$0501 (31.3%) and DRBl$^*$1501 (9.2%) among Koreans. This study shows that DNA typing method using PCR technique is a relatively simple, fast and practical tool for the determination of the HLA-class I and II genes. Moreover, the data of HLA gene frequencies could be useful for the Korean database before clinical applications, including organ and unrelated bone marrow transplantation, anthropological study, disease association and individual identification.

• Parasites, Hosts and Diseases
• /
• v.21 no.2
• /
• pp.116-186
• /
• 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.

• Korean journal of applied entomology
• /
• v.49 no.3
• /
• pp.219-226
• /
• 2010

This paper presents the occurrence and damage characteristics of the rice leaf-folder populations in the paddy fields of Dangsu-dong, Suwon from 2004 to 2007, and also reports the insecticide response of rice leaf-folder populations, which were collected from 2005 to 2006 in Korea and Vietnam. Laboratory measurements of the head capsule width and body length data enabled the identification of the rice leaf-folder larva stages collected in the field. The rice leaf-folder population in Suwon from 2004 to 2007 has a clear pattern consisting of two different group: the low and high density years. During the low density years (2004 and 2006), only one adult peak was noted in late August, with the damaged-hill percent less than 10% in late July, and the damaged-leaf percent around 2% in September. In contrast, during the high density years (2005 and 2007), two adult peaks were noted in early August and mid-September, with the damaged-hill percent was around 30% in late July, and the damaged-leaf percent 15 to 30% in September, which was beyond the economic injury level of rice leaf-folder. High correlations existed between the occurrence of rice leaf-folder in late July and early August and damages to rice during September. Based on these results, we suggest that the information on the rice leaf-folder population monitored by the adult density or damaged-hill percent in late July and early August would be very useful for predicting the damages later in the season for aiding in decision-making for timely control. In addition, the regional populations of rice leaf-folder showed the similar responses to the insecticides tested: high susceptibility to IGRs (tebufenozide and methoxyfenozide) and organophosphates (chlorpyrifos-methyl, pyridaphenthion), but relatively low to cartap.

• Journal of Applied Biological Chemistry
• /
• v.53 no.2
• /
• pp.65-70
• /
• 2010

Medium-chain fatty acids (MCFA) are composed of 8-12 carbon atoms, and are found in coconut, cuphea, and palm kernel oil. MCFA were introduced into clinical nutrition in the 1950s for dietary treatment of malabsorption syndromes because of their rapid absorption and solubility. Recently, MCFA have been applied to Gastrointestinal Permeation Enhancement Technology (GIPET), which is one of the most important parts in drug delivery system in therapeutics. Therefore, to accumulate the MCFA in seed oil of rapeseed, much effort has been conducted by classical or molecular breeding. Laurate can be successfully accumulated up to 60 mol% in the seed oil of rapeseed by the expression of bay thioesterase (Uc FatB1) alone or crossed with a line over-expressing the coconut lysophosphatidic acid acyltransferase (LPAAT) under the control of a napin seed-storage protein promoter. Also, caprylate and caprate were obtained 7 mol% and 29 mol%, respectively, from plants over-expressing of the medium-chain specific thioesterase (Ch FatB2) alone or together with the chain-length-specific condensing enzyme (Ch KASIV). Despite the success of some research in utilizing parallel classical and molecular breeding to produce MCFA, commercially available seed oils have for the most part, not been realized. Recent research in the field of developing MCFA-enriched transgenic plants has established that there is no single rate-limiting step in the production of the target fatty acids. The purpose of this article is to review some of the recent progress in understanding the mechanism and regulation of MCFA production in seed oil of rapeseed.

• Korean Journal of Weed Science
• /
• v.11 no.3
• /
• pp.174-177
• /
• 1991

This study was conducted to determine the influence of dithiopyr on growth of transplanted rice with different transplanting depths and the amount of $^{14}C$-dithiopyr adsorpted in the root and shoot of rice plants under paddy soil conditions. The growth rate of transplanted rice was lower in 0 and 0.25cm of transplanting depths with exposed basal stem than in 1 and 2cm of the depths in control plot. In the growth of transplanted rice treated with dithiopyr, plant hight and dry weight were significantly inhibited in 0 and 0.25cm depth plots but not affected.in 0.5, 1, 2 and 4cm depth plots, and roop length were influenced in 0, 0.25 and 4cm depth plots but not in 0.5, 1 and 2cm depth plots. The amount of ratioactivity in shoot and root of rice plants as affected by $^{14}C$-dithiopyr were the highest in 0 and 0.25cm depth plots and decreased in over 0.5cm depth plots. However the extent in amount of distributed radioactivity in the plants among the different transplanting depths was narrow gradually with the growth of plants. Therefore, injury of transplanted rice by dithiopyr is little in over 0.5cm transplanting depth with burried basal stem and the inhibition on rice plants with extreme shallow transplanting such as 0 and 0.25cm depths should be due to more adsorption of dithiopyr.

• Journal of Aquaculture
• /
• v.19 no.4
• /
• pp.275-280
• /
• 2006

Effect of the various sources of dietary additives on growth, body composition and shell color of abalone Haliotis discus hannai was investigated for 16 weeks. Forty juvenile abalone averaging 13.5 g were randomly stocked into 21 of 50 L plastic rectangular containers each. Eight kinds of additives were prepared for this study: four commercially available microalgae [Haeatococcus (Hae), Isochrysis galbana (Iso), Shizochytrium (Sch) and Spirulina (Spi)], three crustacean meals [krill meal (KM), shrimp head meal (Shm) and red crab meal (Rcm)], and green tea by-product (Gre). In addition, dry sea tangle (Dst), Laminaria japonica, as a control, was prepared. Casein, dextrin and a mixture corn oil and fish oil was protein, carbohydrate and lipid sources, respectively, in the experimental diets. The 2% each additive was included into the experimental diets. The experimental diets were fed to abalone once a day at the ratio of $1.5{\sim}2.0%$ total biomass of abalone with a little leftover throughout the 16-week feeding trial. Survival of abalone was not significantly (P>0.05) affected by the experimental diets. However, weight gain of abalone fed the all experimental diets containing the various sources of additives was significantly (P<0.05) higher than that of abalone fed the Dst diet. Weight gain of abalone fed the Spi diet was highest and Shi, KM and Iso diets in order. Shell length and the ratio of soft body weight to body weight of abalone was not significantly (P>0.05) affected by the experimental diets. However, shell width of abalone fed the all experimental diets containing the various sources of additives was significantly (P<0.05) higher than that of abalone fed the Dst diet. The shell color of abalone fed the Spi diet was improved the most distinctively and similar to that of natural abalone. Therefore, it can be concluded that the experimental diets with the various sources of additives (microalgae and crustacean meals) was effective to improve growth of abalone and dietary inclusion of Spirulina was most effective to improve shell color of abalone.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.30 no.6
• /
• pp.465-473
• /
• 2004

Purpose : The essential triad for nerve regeneration is nerve conduit, supporting cell and neurotrophic factor. In order to improve the peripheral nerve regeneration, we used polyglycolic acid(PGA) tube and brain-derived neurotrophic factor(BDNF) gene transfected Schwann cells in sciatic nerve defects of SD rat. Materials and methods : Nerve conduits were made with PGA sheet and outer surface was coated with poly(lactic-co-glycolic acid) for mechanical strength and control the resorption rate. The diameter of conduit was 1.8mm and the length was 17mm Schwann cells were harvested from dorsal root ganglion(DRG) of SD rat aged 1 day. Schwann cells were cultured on the PGA sheet to test the biocompatibility adhesion of Schwann cell. Human BDNF gene was obtained from cDNA library and amplified using PCR. BDNF gene was inserted into E1 deleted region of adenovirus shuttle vector, pAACCMVpARS. BDNF-adenovirus was multiplied in 293 cells and purified. The BDNF-Adenovirus was then infected to the cultured Schwann cells. Left sciatic nerve of SD rat (250g weighing) was exposed and 14mm defects were made. After bridging the defect with PGA conduit, culture medium(MEM), Schwann cells or BDNF-Adenovirus infected Schwann cells were injected into the lumen of conduit, respectively. 12 weeks after operation, gait analysis for sciatic function index, electrophysiology and histomorphometry was performed. Results : Cultured Schwann cells were well adhered to PGA sheet. Sciatic index of BDNF transfected group was $-53.66{\pm}13.43$ which was the best among three groups. The threshold of compound action potential was between 800 to $1000{\mu}A$ in experimental groups which is about 10 times higher than normal sciatic nerve. Conduction velocity and peak voltage of action potential of BDNF group was the highest among experimental groups. The myelin thickness and axonal density of BDNF group was significantly greater than the other groups. Conclusion : BDNF gene transfected Schwann cells could regenerate the sciatic nerve gap(14mm) of rat successfully.

• Korean Journal of Environmental Biology
• /
• v.21 no.3
• /
• pp.234-239
• /
• 2003

3-weeks old Commelina was transferred to and grown in Hoagland solution (($\pm 100 \mu M \;Cd^{2+}, 100 \mu M \;Cd^{2+}+10 \mu M\;IAA,100 \mu M\; Cd^{2+}+100 \mu M \; IAA,100 \mu M \; Cd^{2+} +1 \mu M \; IAA)$) for three weeks and then a number of physiological activities was investigated. In the control the length of stem was increased to 7 cm after 3 weeks, but in the treatment of $Cd^{2+}$, 2.0 cm was grown. In cases of IAA with $Cd^{2+}$, the growth of the plants was increased to 3.7 cm, 5.0 cm and 3.3 cm in 100 $\mu$M, 10 $\mu$M and 1 mM IAA respectively, Cadmium stimulated stomatal opening. The stomata, treated with $Cd^{2+}$ opened to n degree of about 6.1 $\mu\textrm{m}$, but the stomata, treated with no cadmium opened to 4.5 $\mu\textrm{m}$. In the treatment of various concentation of IAA with cadmium the stomata opend to about 1 $\mu\textrm{m}$ more than that of cadmium alone. Cadmium reduced total chlorophyll content up to 13% for 3 weeks. In the treatment of $Cd^{2+}$ ＋ IAA (10 $\mu$M and 100 $\mu$M) the clear change of total chlorophyll content was not observed, but in the addition of 1 mM IAA to $Cd^{2+}$ reduced the total chlorophyll content to about 9%. $Cd^{2+}$ reduced to 9% and 11% of Fv/Fm after two and three weeks respectively. In cases of IAA with $Cd^{2+}$, there were no clear changes of Fv/Fm. Cadmium reduced water potential to 67% after 3 weeks incubation, but in cases of IAA with $Cd^{2+}$, water potential was not clearly changed. Therefore, it could be concluded that the treatment of IAA showed clear alleviation of $Cd^{2+}$-induced several physiological toxicities.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.28 no.2
• /
• pp.194-201
• /
• 1995

In order to make clear the resistance of bag nets, the resistance R of bag nets with wall area S designed in pyramid shape was measured in a circulating water tank with control of flow velocity v and the coefficient k in $R=kSv^2$ was investigated. The coefficient k showed no change In the nets designed in regular pyramid shape when their mouths were attached alternately to the circular and square frames, because their shape in water became a circular cone in the circular frame and equal to the cone with the exception of the vicinity of frame in the square one. On the other hand, a net designed in right pyramid shape and then attached to a rectangular frame showed an elliptic cone with the exception of the vicinity of frame in water, but produced no significant difference in value of k in comparison with that making a circular cone in water. In the nets making a circular cone in water, k was higher in nets with larger d/l, ratio of diameter d to length I of bars, and decreased as the ratio S/S_m$ of S to the area $S_m$ of net mouth was increased or as the attack angle 9 of net to the water flow was decreased. But the value of ks15m was almost constant in the region of S/S_m=1-4$ or $\theta=15-90^{\circ}$ and in creased linearly in S/S_m>4 or in $\theta<15^{\circ}$ However, these variation of k could be summarized by the equation obtained in the previous paper. That is, the coefficient $k(kg\;\cdot\;sec^2/m^4)$ of bag nets was expressed as $$k=160R_e\;^{-01}(\frac{S_n}{S_m})^{1.2}\;(\frac{S_m}{S})^{1.6}$$ for the condition of $R_e<100$ and $$k=100(\frac{S_n}{S_m})^{1.2}\;(\frac{S_m}{S})^{1.6}$$ for $R_e\geq100$, where $S_n$ is their total area projected to the plane perpendicular to the water flow and $R_e$ the Reynolds' number on which the representative size was taken by the value of $\lambda$ defined as $$\lambda={\frac{\pi d^2}{21\;sin\;2\varphi}$$ where If is the angle between two adjacent bars, d the diameter of bars, and 21 the mesh size. Conclusively, it is clarified that the coefficient k obtained in the previous paper agrees with the experimental results for bag nets.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.34 no.2
• /
• pp.103-108
• /
• 2001

Toxic effect of TBTO on larva flounder was studied by the use of a food-chain system in which indirect toxicity from seawater or/and plankton can be measured, Under the treatment of 0.5 ng/L TBTO, the combined effect of diets ( Chlorella and rotifer) and seawater was significant by synergism, although the sole effect from TBTO treated diets or seawater was equally not, The values of $LT_{50}$ from results of acute-toxicity experiments for juvenile flounder were estimated to be 230.0, 48.0, 24.0, 14.6, 9.3 5.5 3.0 and 1.7 hr at 1, 10, 25, 50, 100, 250, 500 and 1000 ng/L of TBTO, respectively, and $96hr-LC_{50}$ was 3.5 ng/L. From the above results, the experiments for chronic toxicity of TBTO was executed at the concentration range of $1\sim10 ng/L$. In long-term experiments for four months, the weight and the total length of the juvenile flounder in all TBTO treated experiments slowly increased when compared to control. No significant differences in the growth and survival of the juvenile flounder were found in the treatment of 1 ng/L TBTO(P>0.05), But, $90\%$ of the juvenile flounder died in 20 days under TBTO treated seawater at both concentrations of 5 and 10 ng/L, The TBTO treated on seawater was more effective and significantly different in the growth and survival of the juvenile flounder when compare with that on artificial diets (P<0.05). From the all results, TBTO should be regulated below 5 ng/L in a coast.