• The Korean Journal of Pharmacology
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• v.17 no.1 s.28
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• pp.17-25
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• 1981

No evidence has accumulated that lead compound is an essential component for biological function in animals. Lead is absorbed primarily through the epithelial mucosal cells in duodenum and the absorption can be enhanced by the substances which bind lead and increase its solubility. Iron, zinc and calcium ions, however, decrease the absorption of lead without affecting its solubility, probably by competing for shared absorptive receptors in the intestinal mucosa. Therefore, the absorption of lead is increased in iron deficient animals. Lead shows a strong affinity for ligands such as phosphate, cysteinyl and histidyl side chains of proteins, pterins and porphyrins. Hence lead can act on various active sites of enzymes, inhibiting the enzymes which has functional sulfhydryl groups. lead inhibits the activity of ${\delta}$-aminolevulinic acid dehydratase for the biosynthesis of hemoproteins and cytochrome, which catalyzed the synthesis of monopyrrole prophobilinogen from ${\delta}$-aminolevulinic acid. Accordingly lead decrease hepatic cytochrome p-450 content, resulting an inhibition of the activity of demethylase and hydroxylase in liver. Little informations are available on the effect of lead on digestive system although the catastrophic effects of lead intoxication are well documented. The present study was, therefore, attempted to investigate the effect of lead on pancreaticobiliary secretion in rats. Albino rats of both sexes weighing $170{\sim}230g$ were used for this study. The animals were divided into one control and three treated groups, i.e., control (physiologic saline 1.5ml/kg i.p.), lead acetate $(l0{\mu}mole/kg/day\;i.p.)$, $Pb(Ac)_2$ and EDTA$(each\;10{\mu}mole/kg/day\;i.p.)$, $Pb(Ac)_2$ and $FeSO_4(each\;l0{\mu}mole/kg/day\;hp)$. The pancreatico-biliary juice was collected under urethane anesthesia, and activities of amylase and lipase were determined by employing Sumner's and Cherry and Crandall's methods. The summarized results are follows. 1) In the experiment for acute toxicity of lead acetate, 20% of mortality was observed in rat treated with lead acetate as well as inhibition of the activity of amylase in the juice at the 3 rd day of the treatment. 2) No increases in body weight were observed in rats treated with lead acetate, while in control group the significant increases were observed. However, the body weights of animals were increased in the group lead acetate plus EDTA or $FeSO_4$. 3) Lead acetate decreased significantly the volume of pancreatico-biliary juice whereas additional treatment of EDTA and $FeSO_4$ prevented it. 4) Total activity of amylase was markedly reduced due to lead acetate treatment, but no change was showed following additional treatment with EDTA and $FeSO_4$. 5) No changes in the cholate and lipase output were observed in rats treated with lead acetate as compared with that of control rats. 6) Increase in bilirubin output in rats treated with lead acetate was shown on the 2nd and 3rd weeks treatment. 7) In the case of in vitro experiment, lead acetate also markedly inhibited release of amylase from pancreatic fragment. 8) Histologic finding indicated that acini vacuolation was induced in the pancreatic tissue of rat treated with lead acete. From the above results, it might be concluded that lead acetate decreases the volume of pancreatico-biliary secretion and inhibits the amylase activity, by acting directly on pancreatic cells.

• Development and Reproduction
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• v.7 no.1
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• pp.49-56
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• 2003

There have been reports that administrated high-dose gonadotropin-releasing hormone-agonist(GnRH-Ag) suppresses endogenous gonadotropin production and inhibits function of ovary. In human IVF-ET program, however, GnRH-Ag is employed in large amounts during superovulation induction resulting to luteal phase defects which must be supported with progesterone. To elucidate the reason of luteal phase defects by GnRH-Ag, the aim of this study was to investigate the apoptosis changes in the ovary and the hormonal changes in the serum after GnRH-Ag and PMSG administration in adult mice in a method similar to human superovualtion induction. GnRH-Ag(10 ${\mu}$g) or saline was injected every 12h beginning 48h prior to PMSG injection until 48h at)or PMSG injection when blood sampling and ovary collection was performed. In results, the ovary weight in the GnRH-Ag only injection group was significantly lower when compared with the other two groups, PMSG only or PMSC + GnRH-Ag injection. The ratio of preantral follicles in the ovary are increased in the GnRH-Ag only group, while the ratio of antral follicles are decreased and the corpus luteum ratio is increased in the PMSG + GnRH-Ag group. The proportion of all follicles showing apoptosis in the GnRH-Ag only in.iection group was seen to be more than twice the proportion seen in the PMSC only injection group, and such increased apoptosis is decreased after addition of PMSC. The serum levels of both estradiol and progesterone were significantly lower in the CnRH-hg only group compared to those in the other two groups. When the administration of GnRH-Ag were followed by PMSG in;ection, however, estradiol concentration was completely recovered compared to the serum level of PMSG group, but not progesterone level. In conclusion the use of GnRH-Ag in human IVF-ET program may induce the apoptosis and the suppression of hormone production by ovary leading to luteal phase defects, thus adequate progesterone support seems to be necessary against them.

• Korean Journal of Medicinal Crop Science
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• v.4 no.2
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• pp.139-144
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• 1996

This research was carried out to clarify effects of cultural condition on the content of Alisol B-monoacetate, whose function is antihypercolesterol in blood, and yield in Alisma Rhizomes. When the corm part of Alisma Rhizomes was extracted by shaking extraction at $25^{\circ}C$ and reflux extraction at $40^{\circ}C$ to $100^{\circ}C$ four times, the total content of Alisol B-monoacetate was 0. 402%, 0. 425% and 0. 402% at $25^{\circ}C$, $40^{\circ}C$ and $60^{\circ}C$ respectively. The recovery rate was 97% by three times extraction at $25^{\circ}C$, and 96% and 97% by three times extraction at $40^{\circ}C$ and $60^{\circ}C$ respectively. When the corm was harvested on Oct. 30, the content of Alisol B-monoacetate was 0. 46% but it was increased to 0. 71% on Nov. 30. In the case of Oct. 30, the corms of $S(4{\sim}14g\; FW)$ size were determined to contain the highest level of Alisol B-monoacetate (0. 53%), and the content was decreased as the corn size was increased. This tendency was also adopted on Nov. 30. On the other hand, the content of crude protein and starch was changed rarely by the period of harvest. When the planting depth was $0{\sim}1cm$, the yield was the highest as 206kg/10a, and the yield was decreased as the planting depth was deep. The variation of the content of Alisol B-monoacetate was small as 0. 33% to 0. 39% by planting depth. From the above results it could be concluded that the optimum time for harvest of Alisma Rhizomes is Nov. 30 and the optimum planting depth is $0{\sim}1cm$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.4
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• pp.603-607
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• 2003

To investigate the alcohol metabolizing system in liver of rats drunken 10% ethanol with Monascus pigment extract (MPE), Sprague-Dawley male rats weighing about 250 g have been drunken 10% ethanol containing 1, 2.5 and 5% Monascus pigment extract for a month. Three groups of rats drunken 10% ethanol with MPE gained somewhat less body weight than normal group, but the changes of body weight was not significantly different among the former groups. All groups drunken MPE supplemented alcohol had no remarkable changes in liver function on the basis of liver weight/body weight, the serum levels of alanine aminotransferase and xanthine oxidase activity. 10% alcohol drunken animals (control group) showed significantly increased activity of hepatic alcohol dehydrogenase (ADH) by 87% compared with normal group and the animals drunken 1%, 2.5% and 5% MPE showed respectively 34%, 29% and 21% increased activity of hepatic ADH, whileas Km value of ADH in 1, 2.5 and 5% MPE group decreased by 40%, 30% and 19% respectively compared with the control, but Vmax showed no significant changes among MPE groups. In case of aldehyde dehydrogenase (ALDH), 1% MPE group showed significantly increased activity by 32% and 2.5% or 5% MPE group showed increasing tendency compared with control, and Km value in three experimental groups declined by 27% and no particular changes were found among those. Furthermore, Vmax value in 1, 2.5 and 5% MEP group increased by 88,56 and 22% respectively with the control. In the aspect of the area under the curve of a ethanol concentration versus time (AUC) profile obtained after administration of 10% alcohol with 1 or 5% MPE, the decreasing rate of AUC to the control was 18% in 1% MPE treated rats whereas 10% in 5% MPE group.

• Applied Microscopy
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• v.30 no.2
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• pp.173-183
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• 2000

This study was designed to observe the ultrastructural localization of synoviocytes, which are concerned with the function of phagocytic synovial cells (type A synoviocytes, macrophage-like synoviocytes), in the knee joint of the human for CD14 and CD105 by cryo-immune-electron microscopic technique. The synovium were dissected and fixed for two hours (in 4% paraformaldehyde and 0.1% glutaraldehyde mixture), and were immerged in 2.3 M sucrose and 20% PVP solution. Finally, they were cut with the cryoultramicrotome and labelled with primary antibodies (monoclonal mouse anti-human CD14, monoclonal mouse anti-human CD105 (endoglin) and secondary (donkey anti-mouse IgG) tagged with 6 nm colloidal gold particles. The tissues were observed under transmission electron microscope. This study was resulted as follows. 1. In the synovium of the human knee joint, CD14+ cells were identified. These cells showed phagocytic synovial cell's features. In the phagocytic synoviocyte, the distributions of CD14 were marked in the cytoplasm, around vacuoles, and in cytoplasmic process, but not detected inside of vacuoles. 2. In the synovium of the human knee joint, CD105+ cells were identified. These cells were recognized endothelial cells and phagocytic synovial cells. In the phagocytic synovial cells, the distributions of CD105 (endoglin) were marked in cytoplasic process, around vacuoles, and in cell membrane, but not detected inside of vacuoles. On the basis of above findings, it is obvious that phagocytic synovial cells were marked at CD 14 and CD 105, and might be play the role of activated macrophages or phagocytes in the synovial membrane.

• Childhood Kidney Diseases
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• v.3 no.2
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• pp.153-160
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• 1999

Purpose : Present study was undertaken to find out significance of clinical presentation, initial laboratory data and renal biopsy findings on subsequent clinical course of IgA nephropathy in children. Methods : Clinical and laboratory data were analysed retrospectively from 60 children who have been admitted to the Pediatric Department of Kyungpook National University Hospital for the past 11 years and diagnosed as IgA nephropathy. Renal biopsy findings were graded according to the pathologic subclass proposed by Haas. Results : Pathologic grading according to Haas subclassification showed 10 cases in subclass I, 36 in II, 12 in IV and 2 in V and none in subclass II. Sex distribution showed male predominance (male to female ratio = 3 : 1) and mean age at onset of disease was $10.4{\pm}2.8$ years. Episodes of gross hematuria was seen in 71.7% and IgA level increased in 28.3% of children and these were not associated with pathologic grading nor clinical outcomes. With increasing subclass grading, serum protein and albumin decreased and 24 hours urinary protein excretion increased. Normalization of urinalysis (disappearance of hematuria) was seen in 14% at 1-2 years and 37.1% at 3-4 years of follow up period. In 3 cases, renal function deteriorated progressively and they belonged one each to the Haas subclass III, IV and V. Conclusion : In children with IgA nephropathy, progression to chronic renal failure appears to be quite high and pathologic grading according to Haas' subclassification seems to predict patient's outcome faily well. However, firm conclusion cannot be drawn from present study due to the small numbers of patients and short follow-up period. Therefore further multicenter study involving larger numbers of patients and longer periods of follow-up over 10 years was to be undertaken.

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

• Journal of Korea Game Society
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• v.4 no.4
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• pp.11-18
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• 2004

The on-line games in the past were played by only two persons exchanging data based on one-to-one connections, whereas recent ones (e.g. MMORPG: Massively Multi-player Online Role-playings Game) enable tens of thousands of people to be connected simultaneously. Specifically, Korea has established an excellent network infrastructure that can't be found anywhere in the world. Almost every household has a high-speed Internet access. What made this possible was, in part, high density of population that has accelerated the formation of good Internet infrastructure. However, this rapid increase in the use of on-line games may lead to surging traffics exceeding the limited Internet communication capacity so that the connection to the games is unstable or the server fails. expanding the servers though this measure is very costly could solve this problem. To deal with this problem, the present study proposes the load distribution technology that connects in the form of local clustering the game servers divided by their contents used in each on-line game reduces the loads of specific servers using the load balancer, and enhances performance of sewer for their efficient operation. In this paper, a cluster system is proposed where each Game server in the system has different contents service and loads are distributed efficiently using the game server resource information such as CPU utilization. Game sewers having different contents are mutually connected and managed with a network file system to maintain information consistency required to support resource information updates, deletions, and additions. Simulation studies show that our method performs better than other traditional methods. In terms of response time, our method shows shorter latency than RR (Round Robin) and LC (Least Connection) by about 12%, 10% respectively.

• Journal of the Korean Society for Library and Information Science
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• v.4
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• pp.43-71
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• 1975

Operations research has developed rapidly since its origins in World War II. Practitioners of O. R. have contributed to almost every aspect of government and business. More recently, a number of operations researchers have turned their attention to library and information systems, and the author believes that significant research has resulted. It is the purpose of this essay to introduce the library audience to some of these accomplishments, to present some of the author's hypotheses on the subject of library management to which he belives O. R. has great potential, and to suggest some future research directions. Some problem areas in librianship where O. R. may play a part have been discussed and are summarized below. (1) Library location. It is usually necessary to make balance between accessibility and cost In location problems. Many mathematical methods are available for identifying the optimal locations once the balance between these two criteria has been decided. The major difficulties lie in relating cost to size and in taking future change into account when discriminating possible solutions. (2) Planning new facilities. Standard approaches to using mathematical models for simple investment decisions are well established. If the problem is one of choosing the most economical way of achieving a certain objective, one may compare th althenatives by using one of the discounted cash flow techniques. In other situations it may be necessary to use of cost-benefit approach. (3) Allocating library resources. In order to allocate the resources to best advantage the librarian needs to know how the effectiveness of the services he offers depends on the way he puts his resources. The O. R. approach to the problems is to construct a model representing effectiveness as a mathematical function of levels of different inputs(e.g., numbers of people in different jobs, acquisitions of different types, physical resources). (4) Long term planning. Resource allocation problems are generally concerned with up to one and a half years ahead. The longer term certainly offers both greater freedom of action and greater uncertainty. Thus it is difficult to generalize about long term planning problems. In other fields, however, O. R. has made a significant contribution to long range planning and it is likely to have one to make in librarianship as well. (5) Public relations. It is generally accepted that actual and potential users are too ignorant both of the range of library services provided and of how to make use of them. How should services be brought to the attention of potential users? The answer seems to lie in obtaining empirical evidence by controlled experiments in which a group of libraries participated. (6) Acquisition policy. In comparing alternative policies for acquisition of materials one needs to know the implications of each service which depends on the stock. Second is the relative importance to be ascribed to each service for each class of user. By reducing the level of the first, formal models will allow the librarian to concentrate his attention upon the value judgements which will be necessary for the second. (7) Loan policy. The approach to choosing between loan policies is much the same as the previous approach. (8) Manpower planning. For large library systems one should consider constructing models which will permit the skills necessary in the future with predictions of the skills that will be available, so as to allow informed decisions. (9) Management information system for libraries. A great deal of data can be available in libraries as a by-product of all recording activities. It is particularly tempting when procedures are computerized to make summary statistics available as a management information system. The values of information to particular decisions that may have to be taken future is best assessed in terms of a model of the relevant problem. (10) Management gaming. One of the most common uses of a management game is as a means of developing staff's to take decisions. The value of such exercises depends upon the validity of the computerized model. If the model were sufficiently simple to take the form of a mathematical equation, decision-makers would probably able to learn adequately from a graph. More complex situations require simulation models. (11) Diagnostics tools. Libraries are sufficiently complex systems that it would be useful to have available simple means of telling whether performance could be regarded as satisfactory which, if it could not, would also provide pointers to what was wrong. (12) Data banks. It would appear to be worth considering establishing a bank for certain types of data. It certain items on questionnaires were to take a standard form, a greater pool of data would de available for various analysis. (13) Effectiveness measures. The meaning of a library performance measure is not readily interpreted. Each measure must itself be assessed in relation to the corresponding measures for earlier periods of time and a standard measure that may be a corresponding measure in another library, the 'norm', the 'best practice', or user expectations.

• Journal of Nutrition and Health
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• v.36 no.9
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• pp.898-907
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• 2003

Antioxidative function of uncooked powdered food (Sangsik) was evaluated in rats consuming nutritionally unbalanced diet including 1％ cholesterol, high proportion of animal lipids (lard : soybean oil : 8 . 2) , sub-optimal levels of vitamin and mineral mixture along with 0.5% ethanol in drinking water. The uncooked powdered food tested in the present study was a mixture composed of 42 kinds of plant foods (cereals, legumes, seaweeds, vegetables, and fruits) supplemented with vitamins and minerals, and dietary fiber. Control rats were fed the semi-purified diet based on the AIN-93G composition, and nutritionally unbalanced rats were divided into 3 groups, and fed one of the following diets with 0.5% ethanol in drinking water for 5 weeks : unbalanced control diet (UC) ,20% Sangsik powder supplemented diet (S20), and 40% Sangsik powder supplemented diet (S40) . Food efficiency ratio was significantly higher in rats fed S40 compared to the value for rats fed UC (p < 0.05). Hepatic level of thiobarbituric acid reactive substances (TBARS) was significantly lower in rats fed UC compared to that for control rats (p < 0.05) , and was not influenced by dietary supplementation of the Sangsik powder. Hepatic superoxide dismutase (SOD) activity was significantly higher in rats fed UC compared to that for control rats (p < 0.05) , and significantly reduced in rats fed S20 or S40 compared to the value for unbalanced control rats. Feeding unbalanced control diet significantly reduced the ratio of hepatic GSH-Px ＋ catalase/SOD activities compared to the value for control rats, and this decrease in the ratio of antioxidant enzyme activities was reversed by adding the Sangsik powder to the diet at 20% (p <0.05) . Based on the results of antioxidant enzyme activities, feeding uncooked powdered diet appears to provide a favorable environment for body's antioxidative defense mechanism. Serum levels of Fe and Cu were significantly lower in rats fed the Sangsik powder supplemented diets compared to the value for unbalanced control rats (p < 0.05) , and levels of Se, Mn, and Zn were also tended to be decreased by dietary supplementation of the Sangsik powder. These results postulate the possibility that ingredients used in the uncooked powdered food may decrease the bioavailability of trace elements in rats.