곤충병원성세균 Xenorhabdus nematophila (Xn)의 일부 대사물질은 대상 곤충의 phospholipase A2 (PLA2)를 억제하여 아이코사노이드 생합성 활성을 저해시킨다. 그러나 이들 세균 대사물질이 억제하는 곤충의 PLA2에 대해서는 알려져 있지 않다. Xn의 배양액에서 화학구조가 동정된 8 가지 대사물질들은 두 종의 나비목 배추좀나방(Plutella xylostella)과 파밤나방(Spodoptera exigua)의 유충에 대하여 살충 활성을 보유했다.특별히 이들 물질은 모두 Bacillus thuringiensis (비티)의 살충력을 크게 향상시켰다. 파밤나방의 세포성 인지질 분해효소(SecPLA2)를 클로닝하고 대장균에서 과발현시켰다. 분리된 SecPLA2를 지방체에서 얻은 인지질과 반응시켰을 때 여러 다가불포화지방산을 해리시켰다. 이 효소활성이 Xn 유래 대사물질들에 의해 뚜렷이 억제되었다. 또한 SecPLA2에 대한 억제효과와 비티 살충력 상승효과 사이에 정의 상관관계를 보였다. 본 연구는 SecPLA2가 Xn 대사물질의 억제 대상 분자 종말점 가운데 하나라고 제시하고 있다.

Suicide gene transfer has been study extensively for therapies in various human diseases. We can evaluate cellular activity of thymidine kinase and cytotoxic effect in colon cancer cells after suicide gene transfer. We observed cellular expression of green fluorescence protein after transfer with adenovirus into colon adenocarcinoma HCT-15 cells. After transfer HSVtk, we also estimated thymidine kinase activity using [3H]-penciclovir and cellular cytotoxicity by MTT assay. After transfer green fluorescence protein into HCT-15 cells, we could observed fluorescence expression in 10 moi concentration. Expression level of green fluorescence protein markedly increased in 30 moi and most of HCT-15 cells expressed green fluorescence protein in 100 moi. By infection with HSVtk in HCT-15 cells and HT-29 cells, thymidine kinase activity in HCT-15 cells was about two fold higher than that HT-29 cells. Thymidine kinase activity at 1 moi concentration makes no difference with 0 moi in both cells. At 10 moi concentration, thymidine kinase activity increased about three fold compared with 1moi in HCT-15 cells, but not observed high increase in HT-29 cells. Thymidine kinase activity at 100 moi showed about three fold increase in HCT-15 cells and one and a half fold in HT-29 cells compared with 10 moi. By treatment of HSVtk at various mois and ganciclovir to HCT-15 cells, we could find that increased cytotoxic effect according to HSVtk concentration. Cellular cytotoxic effect was slightly appeared at 5 moi concentration and intensively increased at 30 moi concentration, dead colon cancer cells were reached about 30% of total colon cancer cells. Cellular cytotoxic effect was consistently increased until 50 moi, and about 50% of cells at 100 moi and less then 50% of HCT-15 cells at 200 moi were survived. Finally, we can identify that suicide gene transfer into HCT-15 cells is performed according to concentration of suicide gene and thymidine kinase activity also increase with HSVtk concentration in both HCT-15 cells and HT-29 cells. Additionally, we also find that suicide gene therapy by HSVtk with ganciclovir intensively increase cellular cytotoxicity in colon cancer cells. Therefore, our findings suggest that suicide gene therapy by HSVtk can affect cytotoxicy for colon cancer cells and eventually seems to influence therapeutic efficacy.

The aim of this study is to find out histomorphologic change and cellular activity of condyle resulted from unilateral mastication by comparison of cell proliferation and apoptosis activity. 30 adult rats were dived to 15 experimental group and 15 control group randomly. Right upper and l ower molars were gently extracted in experimental group, to make unilateral mastication environment. All subjects were sacrificed at 1 week, 2 weeks and 4 weeks by chloroform, and their tissues were prepare to observation. Streptovidin-biotin system for BrdU stanning, was used to determine cellular proliferative activity. TUNEL method was used to determine apoptotic activity. The result for cellular activity was recorded at both of anterior portion and posterior portion of condyle. Hematoxylin and Eosin stanning was used for histiomorphological change. The results were as follows. There were more change in superficial layer than deep layer of condyle in cellular activity. In anterior portion of condyle cartilage, cellular proliferative activity of experimental group was lower than control group and apoptotic activity of experimental group was higher than control group. And apoptotic activity of extracted side in experimental group is the most. In posterior portion of condyle cartilage, cellular proliferative activity of extracted side in experimental group was higher than non-extracted side and control group, And apoptotic activity of extracted side in experimental group was the low. As a result of histomorphological change, there was hyperplasia in posterior region o f extracted side c ondyle i n experimental g roup, but t here was n o change i n unextracted side i n experimental group. There was histomorphological hyperplasia in posterior condyle of experimental group as results of high cellular proliferative activity. There was mainly apoptotic change of anterior portion condyle in experimental group. But there was no histomorphologic change. In other words, there was hyperplasia by increasing of cellular proliferative activity in posterior portion of nonfunctional side condyle. In functional side condyle, there was no histomorphological change in functional condyle, but there was change in cellular activity.

Brown algae is variety of biological compounds, including xanthophyll, pigments, fucoidans, phycocolloids, and phlorotannins. Several studies concerning these types of compounds have pointed out the variety of biological benefits associated with the algae, including antioxidant, anticoagulant, antihypertension, antibacterial, and antitumor activities. Diphlorethohydroxy- carmalol (DPHC) is a phlorotannin compound isolated from the brown algae Ishige okamurae, with various biological activities in vitro and in vivo. Numerous studies have shown that antioxidant assist inhibition of accumulation of fat. So we studied that effect of DPHC isolated from Ishige okamurae modified the accumulation of fat on preadipocyte, 3T3-L1 cells in vitro. First, the viability of cell was analyzed after 0.4, 2, 10, 50 μg/ml of DPHC treatment using MTT (3-[4,5-dimethylthiazo-2-yl]-2,5-diphenyl tetrazolium bromide) assay. Second, proliferation of cell was analyzed after 0.4, 2, 10, 50 μg/ml of DPHC treatment through measure doubling time. 3T3-L1 cell differentiation into adipocyte was analyzed after induction in the induction medium containing DPHC. The metabolic activity was suppressed by DPHC in concentration dependent manner. Doubling of 3T3-L1 was delayed by the treatment of DPHC in concentration dependent manner. DPHC also inhibit accumulation of triglyceride in the adipocyte. The expression of the marker genes for adipocyte differentiation coincided with cytochemical results. Base on them, it is suggested that DPHC suppress proliferation of adipose precursor cell and differentiation into adipocytes.