Induction of apoptosis by 1-(2-hydroxy-5-methylphenyl)-3-phenyl-1,3-propanedione through reactive oxygen species production, GADD153 expression, and caspases activation in human epidermoid carcinoma cells

This study examined the growth inhibitory effects of the structurally related beta-diketones compounds in human cancer cells. Here, we report that 1-(2-hydroxy-5-methylphenyl)-3-phenyl-1,3-propanedione (HMDB) induces growth inhibition of human cancer cells and induction of apoptosis in A431 cells through modulation of mitochondrial functions regulated by reactive oxygen species (ROS). ROS generation occurs in the early stages of HMDB-induced apoptosis, preceding cytochrome c release, caspase activation, and DNA fragmentation. The changes occurred after single breaks in DNA were detected, suggesting that HMDB induced irreparable DNA damage, which in turn triggered the process of apoptosis. Up-regulation of Bad and p21; down-regulation of Bcl-2, Bcl-XL, Bid, p53, and fatty acid synthase; and cleavage of Bax were found in HMDB-treated A431 cells. Glutathione and N-acetylcysteine (NAC) suppress HMDB-induced apoptosis. HMDB markedly enhanced growth arrest DNA damage inducible gene 153 (GADD153) mRNA and protein in a time- and concentration-dependent manner. NAC prevented up-regulation of GADD153 mRNA expression caused by HMDB. These findings suggest that HMDB creates an oxidative cellular environment that induces DNA damage and GADD153 gene activation, which in turn helps trigger apoptosis in A431 cells.     

六株黑木耳两种同工酶的研究

本文对黑龙江省常用六株黑木耳菌种的胞内、胞外酯酶 (EST)及过氧化物酶 (POD)同工酶进行研究 ,结果表明 :黑木耳菌株同一培养时期的各菌株间同工酶谱存在明显差异 ,同一菌株的胞内、胞外同工酶在酶含量和酶带数也存在差异。此差异性可以用来进行菌种鉴定。     

Effect of Wip1 gene silencing on chemotherapy sensitivity of human colon cancer cells

AIM: To observe the inhibitory effect of siRNA targeting to Wip1 gene on the Wip1 gene expression in the colon cancer cells and to investigate the influence of Wip1 gene silencing on the chemotherapy sensitivity of colon cancer cells. METHODS: Wip1-811 siRNA targeting to Wip1 gene was transfected into RKO colon cancer cells with high expression of Wip1 gene. The mRNA expression of Wip1 was measured by real-time PCR. The protein level of Wip1 was detected by Western blotting. The viability of RKO colon cancer cells was measured by MTS assay. The cell apoptosis and cell cycle were analyzed by flow cytometry. RESULTS: Wip1-811 siRNA efficiently inhibited the expression of Wip1 at mRNA and protein levels. The enhanced chemotherapy sensitivity of RKO colon cancer cells was observed after inhibition of Wip1 gene expression. The viability of RKO colon cancer cells was decreased from (89.4±6.6)% to (74.7±3.9)% after treated with 5-fluorouracil (P<0.05) and decreased from (77.9±2.4)% to (66.7±2.9)% after treated with oxaliplatin (P<0.05). The cell apoptotic rate was increased from (7.7±0.5)% to (12.3±3.2)% and from (14.7±2.1)% to (34.0±2.1)% when RKO colon cancer cells were treated with 5-fluorouracil and oxaliplatin, respectively (P<0.05). CONCLUSION: Wip1 gene silencing enhances chemotherapy sensitivity of colon cancer cells.     

安徽宣州黄棕色土和第四纪红土的比较研究及其古气候意义

通过地貌和型面的考察和研究,发现安徽宣州地黄棕色土的层序位于第四纪红土层之上。用ＥＳＲ测年法测得黄棕色土年龄约为８０ｋａＢ．Ｐ．,红土年龄 ２４０ｋａＢ．Ｐ．,。对这两种成土母质的各项理化性状和磁化率指标进行比较研究,发现黄棕色土受风化作用的程度不如第四纪红土。     

阴山北麓农牧交错带景观生态设计——以察右后旗为例

从地处农牧交错带的察右后旗景观生态条件及资源状况着手,在基于土壤类型单元的土地农业适宜性综合评价的基础上,以最佳经济效益为目标,设计出一个生态治理与资源开发并举的,林草田复合的生态经济系统。     

浑善达克沙地南缘飞播固沙植物群落特性的研究

从1998~2001年连续4年对浑善达克沙地南缘飞播固沙植物群落特性研究的结果表明,其主要影响因子是土壤含水率。沙蒿(Artemisia arenaria DC.Prodr.)飞播8年后群落基本趋于稳定。其密度为1500株/hm2左右,盖度为10%左右;杨柴(Hedysarum mongolicum Turcz.)和沙打旺(Astragalus ad-surgens Pall CV.'shada wang')群落密度为800~1000株/hm2,盖度为12%左右。     

消费者对俄罗斯豆油的购买意愿及影响因素分析——基于对黑龙江省边境居民的问卷调查

为了解边境居民对俄罗斯豆油的购买意愿及其影响因素,对黑龙江省主要口岸绥芬河、黑河、东宁、抚远4个城市的居民进行随机抽样调查,利用Logit模型对所得数据进行分析。结果表明:目前黑龙江省边境居民对俄罗斯豆油的接受程度较高并且愿意购买俄罗斯豆油;性别、质量安全关注度、营养成分关注度、家庭月收入等因素显著影响消费者对俄罗斯豆油的购买意愿。     

Actin rearrangements accompanying Aeromonas hydrophila entry into cultured fish cells

Aeromonas hydrophila can enter fish cells and exist as intracellular parasites. Phase-contrast and confocal microscopy were used to examine morphological changes and various cytoskeletal components of infected fish cells. Four fish cell lines were included in this study: (1) AS, (2) BF2, (3) CHSE-214, and (4) EPC cells. Virulent but not avirulent strains of A. hydrophila PPD 134/91 invaded fish cells, causing morphological changes, and inducing microfilament (F-actin) rearrangement. Morphological changes were observed in all infected fish cell lines and could be classified into three different stages. In stage I, the cells became detached from each other and pointed ends were observed. In stage II, tubular cytoplasmic extensions formed at contact points connecting neighbouring cells. The monolayers formed a satellite-like organization and became less confluent. Finally (stage III), cells were heavily infected with bacteria, and bacteria containing vacuoles occupied most of the cells. They eventually detached and lysed. Rearrangement of F-actin was observed as local polymerization (actin clouds) in stage I and massive reorganization in stage III of infection. Actin clouds could have been induced by A. hydrophila for ‘assisted' uptake into the cells. The massive reorganization of actin in stage III may be due to products released by the bacteria and the growth of vacuoles. Pretreatment of fish cells with the microfilament inhibitors such as cytochalasins induced a similar effect. There were little if any rearrangements in intermediate and microtubule filaments during bacterial entry (stages I and II). These results suggest that A. hydrophila may bind to the surface and trigger a signal to the microfilament which then generates the force necessary for bacterial uptake.     

不同施氮水平下3种类型粳稻光合特性及干物质积累分析

【目的】阐明吉林省主推粳稻品种在不同氮水平下光合特性及干物质积累的差异,为提高稻田氮肥利用率提供依据。【方法】采用大田试验,在不施氮(CK)、1N(纯氮70kg/hm2)、2N(纯氮140kg/hm2)和3N(纯氮210kg/hm2)4种施氮水平下,研究3个吉林省主推水稻品种(吉农大505,吉农大603,吉农大809)灌浆期农艺性状、光合特性和干物质积累特性及产量的变化。【结果】随施氮水平的增加,灌浆期株高、分蘖数和叶面积指数均显著增大。吉农大505在2N条件下剑叶和倒三叶净光合速率最大,吉农大603在3N条件下倒三叶净光合速率较高,吉农大809功能叶净光合速率受施氮水平影响不明显,3个品种净光合速率的差异可能是由于不同氮水平对不同品种冠层结构的影响导致叶片表观叶肉导度不同而引起的。吉农大603和吉农大809茎鞘、叶和穗部的干物质积累量均呈现随施氮水平的增加而增加的趋势,吉农大505茎鞘的干物质积累量在2N水平达到最高值。吉农大603在3N水平产量最高,其他2个品种在2N水平下产量最高,这与对应氮水平条件下各品种灌浆期功能叶片净光合速率、高效叶面积有关。产量与茎鞘、穗及地上部干物质积累量显著或极显著正相关。【结论】不同类型粳稻品种适宜施氮量存在差异,吉农大505和吉农大809相对耐低氮,而吉农大603适宜在高氮下栽培。