원자력 사고 후 대기로 누출된 방사성물질이 지표 토양내 침적된 후 강우에 의하여 주변 환경으로 이동하여 지표수계를 오염시킨다. 지표 토양내 침적된 방사성핵종의 거동 평가를 위하여 수립된 지표 수계 및 토양 유실 모델의 주요 입력자료를 수 집하여 분석하였다. 월성 원전이 위치한 낙동강권역의 하천과 호수에서의 물리적 특성과 주요 생물상의 변화를 파악하기 위해서 원전 주변 수생 환경의 조사 및 분석을 수행하였다. 이를 위해 국내 여러 기관에서 제공하는 수치지도, 수문자료, 수질 및 생태환경자료 등을 수집 분석하여 자료간 상호 연계성을 갖도록 체계적인 DB를 구축하였다. 구축된 수생환경 자료는 지표수계에 흡착된 방사성물질의 중장기 거동 평가를 위하여 수립된 지표수계 유동, 토사유실 및 생태계 모델의 기본 입력자 료로 제공되어 종합적인 방사선영향평가에 활용될 예정이다.

Adult stem cells can make identical copies of themselves for long periods of time. They also give rise to many differentiated mature cell types that have characteristic morphology and specialized function. Human adult stem cells are the attractive raw materials for the cell/tissue therapy, however, it is not easy to get from the adult tissues. In the present study, we tried to isolate a cell population derived from human umbilical cord vein which has been discarded after birth. The cells were isolated after treatment of the umbilical vein with collagenase or trypsin. After 3 days of culture, two kinds of cell populations were found consisting of adherent cells with endothelial cell-like and fibroblast-like morphology, respectively. When these cells were subcultured 12 times over a period of 3 months, almost cells appeared uniformly to exhibit fibroblastoid morphology which was different from that of mesenchymal stem cells obtained from human bone marrow The results of RT-PCR analyses showed distinct expression of BMP-4, oct-4, and SCF genes but not of GATA, PAX-6 and Brachyury genes. On immunohistochemical staining, the cells were negative for the von Willebrand factor(vWF), alpha-smooth muscle actin and placental alkaline phosphatase. From these observations, it is suggested that stem-like cells might be present in human umbilical cord vein.

Coculture of HSC with bone marrow-derived mesenchymal stem cells (BM-MSCs) is one of used methods to increase cell numbers before transplant to the patients. However, because of difficulties to purify HSCs after coculture with BM-MSCs, it needs to develop a method to overcome the problem. In the present study, we have examined whether a culture insert placed over a feeder layer might support the expansion of HSCs within the insert. cells isolated from the umbilical cord blood by using midiMACS were divided into three groups. A group of 1 cells were grown on a culture insert without feeder layer (Direct). The same number of HSCs was directly cocultured with BM-MSCs (Contact). The third group was placed onto an insert below which BM-MSCs were grown (Insert). To distinguish feeder cells from HSCs, BM-MSCs was pre-labeled fluorescently with PKH26 and 1 cells were seeded in the culture dishes. After culture for 13 days, the expansion factor (x) of HSCs that were grown without feeder layer (Direct) was In contrast, the number of HSCs directly cocultured with feeder layer was 59.6 0.5 and that of HSCs cultured onto an insert was The percentage of BM-MSCs cells remained being fluorescent was after culture. Immune-phenotypically large proportion of cultured cells were founded to be differentiated into myeloid/monocyte progenitor cells. The ability of BM-MSCs, fetal lung, cartilage and brain tissue cells to support ex vivo expansion of HSCs was also examined using the insert. After 11 days of coculture with each of these cells, the expansion factor of HSCs was 15.0, 39.0, 32.0 and 24.0, respectively. Based upon these observations, it is concluded that the coculture method using insert is very effective to support ex vivo expansion of HSCs and to eliminate the contamination of other cells used to coculture wth HSCs.