Ochratoxin A (OTA) is one of the most important mycotoxins owing to its widespread occurrence and toxicity including nephrotoxicity and potential carcinogenicity to humans. Since OTA is stable under most food processing conditions, OTA has been detected not only in a wide range of agricultural commodities such as cereal grains but also their processed products. Nonetheless, it is known that significant reduction of OTA may be achieved under higher temperature and alkaline conditions. In this study, the effects of retorting cooking process on the stability of OTA in spiked (20 μg/kg of dry weight basis) rice and oat porridge (10% solid content; w/v) in the presence and absence of baking soda was investigated using a laboratory horizontal steam retort system. The samples were heated in a pot at 85°C central temperature until it becomes gelatinized, packed in retort pouched, and heat-processed in pressurized retort machine (at 121°C for 25 min) followed by drying in 50°C oven overnight. Samples were analyzed for OTA by high-performance liquid chromatography with a fluorescence detector (HPLC-FLD). The reduction of OTA in retorted rice and oat porridge were 54% and 17%, respectively, while greater reduction of OTA was observed at increased amount of baking soda. The reduction of OTA in retorted rice porridge with 0.5% and 1% baking soda were 55% and 66%, respectively. In the retorted oat porridge, reduction of OTA was also evident to result in 30% and 48% with 0.5% and 1.0% of added baking soda, respectively. These results suggest that OTA in rice and oat may be reduced significantly by retorting process. In addition, added baking soda may positively impact the reduction of OTA.

Ochratoxin A (OTA) represents one of the most widespread mycotoxins in agricultural commodities in the world and is considered a possible human carcinogen with its potent nephrotoxicity. Since OTA is stable under most food processing conditions, OTA has been detected in a wide range of cereal grains and their processed products as well. Puffed cereals are commonly used as baby snacks or as ingredients in snack formulations. We investigated the explosive puffing process effect on reduction of OTA in rice and oat. The rice and oat grains were adjusted the moisture content at 16% wet weight basis (wb) and spiked OTA (100 μg/kg), and then puffed by the explosive puffing machine at 5, 7, and 9 kgf. The temperature of chamber was 200°C and the duration times for 5, 7, and 9 kgf were 5, 6, and 9 min, respectively. The reduction of OTA in puffed rice and oat snacks were in the range of 15 – 28% and 38 – 52%, respectively, and the reduction of OTA in puffed rice and oat snacks were decreased with increasing explosive puffing pressures. The moisture content of puffed rice and oat snacks were in the range of 5 – 8% wb and 6 – 10% wb, respectively, and the moisture content in puffed rice and oat snacks were decreased with increasing of explosive puffing pressures. A decrease in bulk density of puffed rice and oat snacks was observed with increased explosive puffing pressure. In addition, increased values of degree of redness (a) in puffed rice and oat samples were observed with increasing explosive puffing pressure. These results suggest that OTA in rice and oat may be reduced significantly by explosive puffing process.

혈청을 이용한 분석은 다양한 질병 진단의 지표로 이용 된다. 혈청의 분리 방법, 저장시간 및 온도에서 부적절한 혈액 처리는 사이토카인의 농도와 생화학 검사결과에 영 향을 줄 수 있다. 본 연구에서는 한우를 공시하여 혈청 분 리 시기, 저장 시간과 온도가 사이토카인 및 생화학 검사 결과에 미치는 영향을 조사 하였다. 혈액은 경정맥에서 채 취하여, 26±3℃에서 1~2시간 방치 후 분리조건을 다음과 같이 4개의 그룹 (a-d)으로 나뉘어 진행하였다. a) 혈청 분 리하여 보관(대조구), b) 혈청분리 후 아이스박스 2시간 방 치 후 보관, c) 아이스박스 2시간 방치 후 혈청분리, d) 24 시간 4℃ 방치 후 혈청분리, 이러한 조건으로 분리된 혈청 은 분석 전까지 –70℃ 보관 하였다. 혈청 분리시기, 아이스 박스 또는 4℃ 저장 시간 및 온도에 따라 IFN-γ는 유의적 인 차이를 보이지 않았고, TNF-α의 농도는 그룹 a-c에 비 해 그룹 d에서 유의적(p<0.05)으로 낮아졌다. 또한 albumin, total protein의 농도는 그룹 a보다 d에서 유의적 (p<0.01)으로 높았고, magnesium, calcium에서도 유사한 결과를 보였다(p<0.05). 그러나 G-GTP의 경우 다른 그룹에 비해 그룹 d에서 유의적(p<0.05)으로 가장 낮아졌다. 그러 므로 시료채취 시 농가와 실험실의 거리를 고려하여 온도와 저장시간이 혈청 내 사이토카인 및 생화학 농도에 미치 는 영향을 최소화 하여 연구 수행을 진행해야 될 것으로 사료된다.

Ochratoxin A, which is frequently detected in cereals and infant diets worldwidely, is a mycotoxin to damage mainly the kidney and liver. Because ochratoxin A is highly thermostable compound. it is necessary to study ways of reducing level of ochratoxin A by controling processing steps. However, food processes, including extrusion, expansion, roasting, and steam cooking, which are used in order to mitigate the contents of ochratoxin A, are known to produce polycyclic aromatic hydrocarbons, which are generated from radicals decomposed by pyrolysis. Therefore, this study analyzed the levels of 4 polycyclic aromatic hydrocarbons, benz (a) anthracene, chrysene, benzo (b) fluoranthene and benzo (a) pyrene in rice-based products made in high pressure and heating process. Rice samples were finely ground, and homogenized samples were alkaline treatement with 1 M KOH/EtOH and extracted with liquid-liquid extraction method using n-hexane. The extracted solution was pretreated with a silica cartridge. The purified solution was dried with nitrogen gas and dissolved in 1 mL of dichloromethane and injected into GC/MSD. We had overall recoveries for 4 polycyclic aromatic hydrocarbons spiked into rice samples ranging from 92.8 to 110.2%. The limit of quantitations of benz (a) anthracene, chrysene, benzo (b) fluoranthene and benzo (a) pyrene in rice-based product were 0.19 ng/g, 0.38 ng/g, 0.51 ng/g, and 0.31 ng/g, respectively. However, these 4 polycyclic aromatic hydrocarbons in all processed rice samples were not detected.

Ski protein is a nuclear transcription factor that does not bind DNA directly. Due to its unique binding properties with multiple factors, Ski could perform various roles in the regulation of both cellular proliferation and differentiation. We had previously reported that Ski protein is present in granulosa cells of atretic follicles, but not in preovulatory follicles, suggesting that Ski has a role in apoptosis of granulosa cells. The alternative fate of granulosa cells other than apoptosis is to differentiate to luteal cells; however, it is unknown whether Ski is expressed and has a role in granulosa cells undergoing luteinization. Thus, the aim of the present study was to examine whether the initiation of luteinization with luteinizing hormone (LH) directly regulates expression of Ski in the luteinized granulosa and luteal cells after ovulation by in vitro models. RT-PCR and real time PCR analysis respectively revealed that LH had no effect on c-Ski mRNA expression in the cultured granulosa cells regardless of LH treatment. Though Ski protein isabsent in granulosa cells of preovulatory follicle, its mRNA(c-Ski) was expressed and the level was unchanged even after LH surge. Taken together, these results demonstrated that Ski protein expression is induced in granulosa cells upon luteinization, and suggested that its expression is regulated post-transcriptionally. Moreover, expression of mRNA of Arkadia, an E3 ubiquitin ligases, in luteinizing granulosa cells in vivo was assessed by real time-PCR. The levels of Arkadia mRNA expression were unchanged during follicular growth and post ovulatory luteinization. These findings suggest that Ski protein level may be regulated during luteinization at translational and/or post-translational level but not by Arkadia.

Sloan-Kettering virus gene product of a cellular pro-oncogene c-Ski is an unique nuclear pro-onco protein and belongs to the Ski/Sno proto-oncogene family. Ski plays multiple roles in a variety of cell types, it can induce both oncogenic transformation and terminal muscle differentiation when expressed at high levels. Ski protein is implicated in proliferation/differentiation in a variety of cells. The alternative fate of granulosa cells other than apoptosis is to differentiate to luteal cells, however, it is unknown whether Ski is expressed and has a role in granulosa cells undergoing luteinization. Thus, the aim of this study was, by means of immunohistochemical methods, to locate Ski protein in the rat ovaries during ovulation and corpora lutea(CL) formation to predict the possible involvement of Ski in luteinization. In addition, to examine whether the initiation of luteinization with luteinizing hormone(LH) directly regulates expression of Ski in the luteinized granulosa and luteal cells after ovulation by in vivo models. In order to examine the expression pattern of Ski protein along with the progress of luteinization, follicular growth was induced by administration of equine chorionic gonadtropin to immature female rat, and luteinization was induced by human chorionic gonadtropin treatment to mimic luteinizing hormone(LH) surge. While no Ski-positive granulosa cells were present in preovulatory follicle, Ski protein expression was induced in response to LH surge, and was maintained after the formation of corpus luteum(CL). These results indicate that Ski is profoundly expressed in the luteinized granulosa cells and luteal cells of CL during luteinization, and suggest that Ski may play a role in luteinization of granulosa cells.

For reconstituting genetic resource(Korean Native Chicken: KNC) with grem-line chimeric chicken made with cryopreserved biastdermal cells, the experiments were carried out to optimize cryopreservating conditions. Stage X biastdemal cells were collected from KNC embryos and dissociated. Cells were susupended in medium containing cyopretectant and fetal bovine serum(FBS), and distributed into plastic ampules. Cell susupensions were seeded to induce ice formation at — 7℃ to — 35℃ at in the experiments, the effect of modification of dissociation way, concentration of FBS and cell density on the vaibility of frezen-thawed cells were investigated by trypan blue exclusion. Then change the way of cell dissociation from pipetting to short time vortexing, viability of frozen- thawed cell tended to be increaced from 29 % to 52 %. Increase concentraition of FBS in frozen medium from 20 % to 80 % made viability of thawed cell from 28 % to 35 %. The viability of thawed cells were 33.9% frozen at 2 embryos/ 0.5 ml, and 43.6 % frozen at 20embryos/0.5 ml. Furthermore, combination of three modifications make big improvement. The viability of frozen-thawed cell was 60 % for combinated method, and 41 % for general method. This result means the advance to practical cryoreservation of blastdermal cell of the KNC(Ogolgye breed).

Ski protein is implicated in proliferation/differentiation in a variety of cells. We had previously reported that Ski protein is present in granulosa cells of atretic follicles, but not in preovulatory follicles, suggesting that Ski has a role in apoptosis of granulosa cells. The alternative fate of granulosa cells other than apoptosis is to differentiate to luteal cells; however, it is unknown whether Ski is expressed and has a role in granulosa cells undergoing luteinization. Thus, the aim of the present study was to locate Ski protein in the rat ovary during luteinizationto predict the possible role of Ski. In order to examine the expression pattern of Ski protein along with the progress of luteinization, follicular growth was induced by administration of equine chorionic gonadtropin to immature female rats, and luteinization was induced by human chorionic gonadtropin treatment to mimic luteinizing hormone (LH) surge. While no Ski-positive granulosa cells were present in preovulatory follicle, Ski protein expression was induced in response to LH surge, and was maintained after the formation of the corpus luteum (CL). Though Ski protein is absent in granulosa cells of preovulatory follicle, its mRNA (c-Ski)was expressed and the level was unchanged even after LH surge. Taken together, these results demonstrated that Ski protein expression is induced in granulosa cells upon luteinization, and suggests that its expression is regulated post-transcriptionally.

For reconstituting genetic resource(Korean Native Chicken: KNC) with grem-line chimeric chicken made with cryopreserved biastdermal cells, the experiments were carried out to optimize cryopreservating conditions. Stage X biastdemal cells were collected from KNC embryos and dissociated. Cells were susupended in medium containing cyopretectant and fetal bovine serum(FBS), and distributed into plastic ampules. Cell susupensions were seeded to induce ice formation at —7 ℃ to —35 ℃ at in the experiments, the effect of modification of dissociation way, concentration of FBS and cell density on the vaibility of frezen-thawed cells were investigated by trypan blue exclusion. Then change the way of cell dissociation from pipetting to short time vortexing, viability of frozen-thawed cell tended to be increaced from 29 % to 52 %. Increase concentraition of FBS in frozen medium from 20 % to 80 % made viability of thawed cell from 28 % to 35 %. The viability of thawed cells were 33.9% frozen at 2 embryos/ 0.5ml, and 43.6 % frozen at 20 embryos/0.5 ml. Furthermore, combination of three modifications make big improvement. The viability of frozen-thawed cell was 60 % for combinated method, and 41 % for general method. This result means the advance to practical cryoreservation of blastdermal cell of the KNC(Ogolgye breed).

Soybean is a crop of importance economically and nutritionally in many parts of the world. Thanks to many new genes brought from genomic research, It is possible to introduce various candidate genes through genetic transformation to see the performance of the genes in field. In our lab, soybean transformations have been tried for last 10 years to probe the possibility of traits improvement by transformation of new gene into soybean. For this purpose, three different genes were transformed into Korean soybean variety, Kwangan. First, the gene that controls early flowering of plant was transformed into Kwangan. Second, a candidate gene for soybean mosaic virus (SMV) resistance was transformed to produce transgenic plants. Third, another candidate gene for drought tolerance was transformed. All the transgenic plants from three genes transformation were produced for their gene insertion and their expression using PCR, qRT-PCR. Further analysis including harvesting seeds is currently undertaken.