• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.775-782
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• 2011

This study was designed to clarify the morphometrical change of lymph node, deep cortex and lymph follicles in draining lymph nodes of young mice in response to local injection of lipopolysaccharide(LPS). 1. In the group stimulated with LPS, aged 0 day and 3 days, the number of lymph follicles were not significantly different from those of control group. 2. In the group two to four weeks after injection with LPS, aged five days and one week, the number of lymph follicles were significantly increased from those of control group. 3. In the group one to four weeks after injection with LPS, aged 0 day, three days, five days and one week, the area of lymph node and deep cortex increased about 1.5-3 times more than that of the control group. 4. In the group two to four weeks after injection with LPS, aged three days, five days and one week, the lymph follicles(the area: larger than 0.1 mm2) were increased from those of control group. 5. In the group two to four weeks after injection with LPS, aged five days and one week, the lymph follicles(the area: smaller than 0.01 mm2) were increased from those of control group. In view of these experimental findings, the formation of lymph follicles were induced by LPS stimulation from 5 days to one week after birth. The newley formed lymph follicles area in response to LPS may be less than $0.01mm^2$.

• The Journal of Korean Philosophical History
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• no.39
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• pp.85-114
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• 2013

Traditional values refer to one's attitudes or perspectives developed by negotiating with oneself, others, society, world, nature and universe, which include thoughts on what is right, desirable, and what is dos and don'ts. The purpose of this study was to investigate values which Korean people traditionally emphasized, and their changes by epochal situation focused on the Choson Era. Also, this study intended to assist in finding values and meaning which should be passed down and manifested in contemporary society based on the study results. In this context, I select some positive values in the background of the Joseon dynasty. As traditional values or ethics in Korea destroyed and distorted going through the period of Japanese colonialism, all the existing social culture and traditional culture were denied, which resulted in vanishing common value which led community for several hundred years. The loss of common value caused community destruction and collapse, and made Korean people seek to survival, success and advancement in life as suffering from severe conflict of values. Experience of hollow state of mind caused by historical and cultural severance left distorted and degenerated values to Korea people, which made them pursue false values without realizing true meaning of traditional values. The true meaning of traditional values should be universal no matter how society changes, and could be milestone to contemporary people wandering aimlessly. Realizing and reconsidering the meaning of traditional values to found comtemporary values of Korean people by reflecting on history can produce significant results beyond age-old debate about East or West, and tradition or modernity.

• Korean Journal of Animal Reproduction
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• v.25 no.4
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• pp.305-315
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• 2001

In this study, the production of transgenic embryo was attempted by microinjection or round spermatid cultured with foreign DNA. At first, the expression of haploid spermatids specific gene, mTP1 in mouse and hPrm2 in hamster spermatids were investigated by RT-PCR method in testes of young mice and hamster testis. The specific gene expression first appeared at 18 days post partum (dpp) in mice spermatid and 20 dpp in hamster spermatid. Therefore, the round spermatids isolated from 17 dpp mice and 19 dpp hamster were used for the introduction of foreign EGFP gene into haploid round spermatids. For the introduction of EGFP gene haploid round spermatids suspended in medium including EGFP gene were treated with a different electric field strength at 0.11, 0.18 and 0.44 ㎸/cm. After electrical stimulation, viability of testicular sperm cells and 67.6%, 66.4% and 49.9%, in mice and 62.6%, 57.9% and 27% in hamster, respectively. These values were significantly lower than those of non-treated control groups 80.5% in mouse and 69.1% in hamster After 72 hrs culture, the highest expression rate of EGFP gene, 28.5% in mice and 32.1% in hamster were obtained from tile spermatogenic cells electroporated by the field strength or 0.18 ㎸/cm. Then, the ability of fertilization and embryonic development of haploid spermatids transfected with foreign EGFP gene were estimated by the microinjection of spermatids into hamster oocytes. The Irate pronuclear formation rate (77.5%) was lower than non-treated control (80%), and the cleavage rate of the treated group (58.8%) was lower than control (65%). To prove the foreign EGFP integration in hamster embryos, 2-cell stage hamster embryos were subjected to the observation under the fluorescence microscope, and the PCR analysis. As a result, about 44% of 2-cell embryos were showed the integration of EFGP gene into their genome. Therefore, These results suggest the possibility to produce transgenic hamsters by microinjection of haploid spermatid transfected with foreign DNA.

• KSBB Journal
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• v.14 no.5
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• pp.593-599
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• 1999

In this study, optimal conditions to infect CD34 positive cells containing hematopoietic stem cells obtained from cord blood and bone marrow were found using two different retroviral vectors expressing human growth hormone (hGH) and $\beta$-galactosidase. CD34 positive cells were successfully infected with recombinant retroviruses only when the CD34 positive cells were co-cultured with packaging cells secreting recombinant retroviruses. To find the highest infection efficiency for the gene transfer, CD34 positive cells from cord blood were co-cultured with packaging cells secreting recombinant retroviruses encoding E. coli lacZ gene. The highest infection efficiency was obtained when CD34 positive cells were cultured for 3 days, and then co-culturing was done for another 2 days. When CD34 positive cells from bone marrow were co-cultured with packaging cells secreting recombinant retroviruses encoding hGH gene, the maximum amount of hGH was also secreted at the same conditions found above, i.e. 3 days of culture and 2 days of co-culture. These results show that there are optimal conditions for the gene transfer into hematopoietic stem cells regardless of sources of target cells or retroviral vectors used to infect.

• Journal of Plant Biotechnology
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• v.34 no.4
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• pp.331-338
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• 2007

One-node stem pieces ca. 1 cm in length containing a axillary bud and a fully expanded leaf were obtained from it in vitro plants of potato (Solanum tuberosum L.). Leaves were removed and the nodes were cultured on the MS medium to investigate the effects of temperature, day length, sucrose, and CCC in microtuber formation and development. The fresh weight of microtubers after 80 days increased significantly at 8% sucrose and $20^{\circ}C$ compared with $28^{\circ}C$. The tuberization and development were reduced at $28^{\circ}C$ except short-day treatment of 8 hours at 8% sucrose. The fresh weight and diameter were increased on the culture medium added CCC 500 mg/L. The potato tuberization was promoted under short daylength, and it showed great effect by treatment with the CCC. Though the tuberization was promoted at low temperature of $20^{\circ}C$ in a histologic change of an axillary bud part cell of a potato, the cells were able to observe the swelling growth. Swelling growth of tissue was stimulated in the darkness and was more remarkable by addition of CCC. In particular, in the visual ratio of cell division for each position in the tissue, the cortex part showed larger ratio of cell expansion than that of the pith part. The effect of CCC was identified at 8% sucrose in the darkness. The effect of CCC was not showed in sucrose 3% under long daylength of 16 hours. As a result, the fact of a substance with AGPase important for starch composition was certified by the result with the inclose of AGPase activity on high concentration of sucrose, CCC, and dark treatment by which tuber formation and development are promoted.

• Applied Microscopy
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• v.40 no.2
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• pp.73-80
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• 2010

Liver regeneration is a result of highly coordinated proliferation of hepatocytes and nonparenchymal liver cells. Partial hepatectomy (PH) is the most often used stimulus to study liver regeneration because, compared with other methods that use hepatic toxins, it is not associated with the tissue injury and inflammation, and the initiation of the regenerative stimulus is precisely defined. Granulocyte macrophage-colony stimulating factor (GM-CSF), which is a cytokine able to regulate the proliferation and differentiation of epithelial cells, was first identified as the most potent mitogen for bone marrow. Particularly, rrhGM-CSF, which is highly glycosylated and sustained longer than any other types of GM-CSF in the blood circulation, was specifically produced from rice cell culture. In this experiment, effects of rrhGM-CSF administration were evaluated in the regenerating liver after 78% PH of rats. Morphological changes induced by PH were characterized by destroyed hepatocyte plate around the central vein and enlarged nuclear cytoplasmic ratio and increased hepatocytes with two nuclei. And then, proliferation of liver cells (parenchymal and nonparenchymal) and rearrangement of plates and lobules seemed to be carried out during liver regeneration. These alterations in the experimental group preceded those of the control. Since proliferating cell nuclear antigen (PCNA) is known to be a nuclear protein maximally elevated in the S phase of proliferating cells, the protein was used as a marker of liver regeneration after PH in rats. PCNA levels by western blot analysis and immunohistology were compared between the two groups. PCNA protein expression of two groups at 12 hr and 24 hr after injury showed similar pattern. The protein expression showed the peak at 3 days in both groups, however, the protein level of the experimental group was higher than that of the control. On immunohistochemical observations, the reaction product of PCNA was localized at the nuclei of proliferating cells and the positive reaction in experimental group at 3 days was clearly stronger than that in control group. The results by Western blotting and immunohistology for PCNA showed similar pattern in terms of the protein levels. In conclusion, rrhGM-CSF administration during liver regeneration after 78% PH accelerated breakdown and restoration of the hepatic plate and expression of PCNA. These results suggest that rrhGM-CSF might play an important role during liver regeneration in rats.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.169-175
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• 2006

The objective of this study was carried out to examine the polar body extrusion of in vitro matured porcine follicular oocytes as a non-invasive marker of oocyte quality to know the developmental competence in advance. The porcine oocytes matured for 48 hours were examined the polar body extrusion and some parts were stained. The examined oocytes were matured for additional $16{\sim}18$ hours and activated with 7% ethanol and cultured in $5{\mu}g/ml$ cytochalasin B for 5 hours for diploid formation. The treated oocytes were washed and cultured for 7 days. The polar body extrusion and degeneration rates were varied with $9.9{\sim}52.4%$ and $21.4{\sim}61.8%$ by repetition. The polar body extruded oocytes were shown the polar body chromosome and metaphase II plate by staining. However the non-extruded oocytes were shown expanded nucleus with 39.1%, premature chromosome condensation with 19.6%, metaphase I plate with 10.9 %, metaphase II with 13%, condensed chromatin with 6.5%, and absent nuclear material with 8.7%. The oocytes that were not examined for the polar body extrusion were cleaved 45.0%, and developed to blastocyst stage with 11.3%. In examined oocytes for polar body extrusion,. the polar body extruded oocytes were cleaved 94.2% and developed with 42.5%. This result suggests that discarding of the degenerating oocytes and oocytes that not extruded polar body will be effective for experiments of culturing effect in porcine embryos and embryo biotechnology.

• Journal of Korean Society of Forest Science
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• v.21 no.1
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• pp.1-34
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• 1974

The author intended to investigate external and internal changes in the cone structure, changes in water content, sugar, fat and protein during the period of seed maturation which bears a proper germinability. The experimental results can be summarized as in the following. 1. Male flowers 1) Pollen-mother cells occur as a mass from late in April to early in May, and form pollen tetrads through meiosis early and middle of May. Pollen with simple nucleus reach maturity late in May. 2) Stamen number of a male flower is almost same as the scale number of cone and is 69-102 stamens. One stamen includes 5800-7300 pollen. 3) The shape is round and elliptical, both of a pollen has air-sac with $80-91{\mu}$ in length, and has cuticlar exine and cellulose intine. 4) Pollen germinate in 68 hours at $25^{\circ}C$ with distilled water of pH 6.0, 2% sugar and 0.8% agar. 2. Female flowers 1) Ovuliferous scales grow rapidly in late April, and differentiation of ovules begins early in May. Embryo-sac-mother cells produce pollen tetrads through meiosis in the middle of May, and flower in late May. 2) The pollinated female flowers show repeated divisions of embryo-sac nucleus, and a great number of free nuclei form a mass for overwintering. Morphogenesis of isolation in the mass structure takes place from the middle of March, and that forms albuminous bodies of aivealus in early May. 3. Formation of pollinators and embryos. 1) Archegonia produce archegonial initial cells in the middle and late April, and pollinators are produced in the late April and late in early May. 2) After pollination, Oespore nuclei are seen to divide in the late May forming a layer of suspensor from the diaphragm in early June and in the middle of June. Thus this happens to show 4 pro-embryos. The organ of embryos begins to differentiate 1 pro-embryo and reachs perfect maturation in late August. 4. The growth of cones 1) In the year of flowering, strobiles grow during the period from the middle of June to the middle of July, and do not grow after the middle of August. Strobiles grow 1.6 times more in length 3.3 times short in diameter and about 22 times more weight than those of female flower in the year of flowering. 2) The cones at the adult stage grow 7 times longer in diameter, 12-15 times shorter diameter than those of strobiles after flowering. 3) Cone has 96-133 scales with the ratio of scale to be 69-80% and the length of cone is 11-13cm. Diameter is 5-8cm with 160-190g weight, and the seed number of it is 90-150 having empty seed ratio of 8-15%. 5. Formation of seed-coats 1) The layers of outer seed-coat become most for the width of $703{\mu}$ in the middle of July. At the adult stage of seed, it becomes $550-580{\mu}$ in size by decreasing moisture content. Then a horny and the cortical tissue of outer coats become differentiated. 2) The outer seed-coat of mature seeds forms epidermal cells of 3-4 layers and the stone cells of 16-21 layers. The interior part of it becomes parenchyma layer of 1 or 2 rows. 3) Inner seed-coat is formed 2 months earlier than the outer seed-coat in the middle of May, having the most width of inner seed-coat $667{\mu}$. At the adult stage it loses to $80-90{\mu}$. 6. Change in moisture content After pollination moisture content becomes gradually increased at the top in the early June and becomes markedly decreased in the middle of August. At the adult stage it shows 43~48% in cone, 23~25% in the outer seed-coat, 32~37% in the inner seed-coat, 23~26% in the inner seed-coat and endosperm and embryo, 21~24% in the embryo and endosperm, 36~40% in the embryos. 7. The content compositions of seed 1) Fat contents become gradually increased after the early May, at the adult stage it occupies 65~85% more fat than walnut and palm. Embryo includes 78.8% fat, and 57.0% fat in endosperm. 2) Sugar content after pollination becomes greatly increased as in the case of reducing sugar, while non-reducing sugar becomes increased in the early June. 3) Crude protein content becomes gradually increased after the early May, and at the adult stage it becomes 48.8%. Endosperm is made up with more protein than embryo. 8. The test of germination The collected optimum period of Pinus koraiensis seeds at an adequate maturity was collected in the early September, and used for the germination test of reduction-method and embryo culture. Seeds were taken at the interval of 7 days from the middle of July to the middle of September for the germination test at germination apparatus.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.11
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• pp.545-561
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• 2007

Location management and message delivery protocol is fundamental to the further development of mobile agent systems in a multi-region mobile agent computing environment in order to control mobile agents and guarantee message delivery between them. However, previous works have some problems when they are applied to a multi-region mobile agent computing environment. First, the cost of location management and message delivery is increased relatively. Second, a tracking problem arises. finally, cloned mobile agents and parent-child mobile agents do not get dealt with respect to location management and message delivery. In this paper, we present a HB (Home-Blackboard) protocol, which is a new location management and message delivery protocol in a multi-region mobile agent computing environment. The HB protocol places a region server in each region and manages the location of mobile agents by using intra-region migration and inter-region migration. It also places a blackboard in each region server and delivers messages to mobile agents when a region server receives location update form them. The HB protocol can decrease the cost of location update and message passing and solve the tracking problem with low communication cost. Also, this protocol deals with the location management and message passing of cloned mobile agents and parent-child mobile agents, so that it can guarantee message delivery of these mobile agents and pass messages without passing duplicate messages.

• Radiation Oncology Journal
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• v.11 no.1
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• pp.35-42
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• 1993

The dose response of the number of micronuclei in cytokinesis-blocked (CB) lymphocytes after in vitro irradiation with $\gamma$-rays and neutrons in the 5 dose ranges was studied for a heterogeneous population of 4 donors. One thousand binucleated cells were systematically scored for micronuclei. Measurements performed after irradiation showed a dose-dependent increase in micronuclei (MN) frequency in each of the donors studied. The dose-response curves were analyzed by a linear-quadratic model, frequencies per 1000 CB cells were ($0.31{\pm}0.049$)D+($0.0022{\pm}0.0002)D^2+(13.19{\pm}1.854) (r^2=1.000,\;X^2=0.7074,\;p=0.95$) following $\gamma$ irradiation, and ($0.99{\pm}0.528$)\;D+(0.0093{\pm}0.0047)\;D^2+(13.31{\pm}7.309)\;(r^2=0.996,\;X^2=7.6834,\;p=0.11) following neutrons irradiation (D is irradiation dose in cGy). The relative biological effectiveness (RBE) of neutrons compared with $\gamma$-rays was estimated by best fitting linear-quadratic model. In the micronuclei frequency between 0.05 and 0.8 per cell, the RBE of neutrons was $2.37{\pm}0.17$. Since the MN assay is simple and rapid, it may be a good tool for evaluating the $\gamma$-ray and neutron response.