慢性胃炎肠化生CD_(44)、CD_(44V6)及Cyclin D_1、Cyclin E的表达和意义

目的探讨慢性胃炎胃粘膜肠化生CD44、CD44V6及cyclin D1、Cyclin E表达的意义。方法利用免疫细胞化学技术对39例伴有肠化生的慢性胃炎和5例正常人胃窦粘膜的活检组织进行检查。结果正常人胃窦粘膜上皮,腺上皮对CD44、CD44V6、Cyclin D1和Cyclin E均为阴性,但在有神经内分泌样细胞的粘膜,CD44V6和cyclin D1为阳性。慢性胃炎肠化生区和不典型增生区除CD44为阴性外,CD44V6、cyclin D1和cyclin E均呈现不同的阳性反应,但未见有阳性的神经内分泌样细胞。间质细胞大都呈阳性反应。结论CD44V6、cyclin D1和cyclin E可能是胃癌前状态的早期事件,而CD44可能为胃癌晚期的标志物。     

Effects of Different Sources and Levels of Zinc on H2O2-Induced Apoptosis in IEC-6 Cells

Zinc has been shown to be an inhibitor of apoptosis for many years. The present study was designed to investigate effects of three zinc chemical forms on H₂O₂-induced cell apoptosis in IEC-6 cells via analysis of cell vitality, LDH activity, apoptosis percentage, caspase-3 activity, and Bcl-2, Bax, and caspase-3, -8, and -9 gene expression. Cells were divided into H₂O₂ and zinc sources+H₂O₂ groups, and there are three different zinc sources [zinc oxide nanoparticle (nano-ZnO), zinc oxide (ZnO), and zinc sulfate (ZnSO₄)] and three concentrations (normal = 25 μM, medium = 50 μM, and high = 100 μM) used in this article. In the present study, we found the striking cytotoxicity of H₂O₂ higher than 200 μM on cell vitality, LDH activity, and apoptosis percentage in the cells using five different concentrations (50, 100, 200, 400, and 800 μM) of H₂O₂ for 4 h. Moreover, we observed that cell vitality was increased, LDH activity and apoptotic percentage were decreased, and gene expression level of Bax and caspase-3 and -9 was markedly reduced, while gene expression level of Bcl-2 and ratio of Bcl-2/Bax were increased in normal concentration groups of nano-ZnO and ZnSO₄ compared with H₂O₂ group, but no significant difference was observed in caspase-8 gene expression. Furthermore, medium or, more intensely, high concentrations of nano-ZnO and ZnSO₄ enhanced H₂O₂-induced cell apoptosis. Compared with nano-ZnO and ZnSO₄, ZnO showed weakest protective effect on H₂O₂-induced apoptosis at normal concentration and was less toxic to cells at high level. Taken together, we proposed that preventive and protective effects of zinc on H₂O₂-induced cell apoptosis varied in IEC-6 cells with its chemical forms and concentrations, and maybe for the first time, we suggested that nano-ZnO have a protective effect on H₂O₂-induced cell apoptosis in IEC-6 cells.     

长白山北坡土壤动物群落物种共有度的海拔梯度变化

群落间各生活型土壤动物科及所有土壤动物科的共有度,一定程度上反映了群落间的相关性及沿环境梯度的物种替代关系。应用梯度格局法在长白山北坡海拔550～2650m地段,每隔100m海拔高度设置一块样地,共计22块样地,并应用Jaccard指数,对各海拔不同土壤动物群落间物种共有度的海拔梯度变化进行了分析。结果表明,不同海拔土壤动物群落间物种的共有度,无论以哪一生活层的土壤动物科来表达,基本都以与其最相邻的群落间为最高,群落间物种共有度峰值与谷点反映了群落类型随海拔具有间断性变化。线虫、甲螨、弹尾等各生活型土壤动物的共有度以及所有土壤动物科的共有度,均随着海拔差的增加呈下降趋势,但并非与植被情况完全吻合。     

Peptide models of four possible insulin folding intermediates with two disulfides

The single-chain insulin (PIP) can spontaneously fold into native structure through preferred kinetic intermediates. During refolding, pairing of the first disulfide A20-B19 is highly specific, whereas pairing of the second disulfide is likely random because two two-disulfide intermediates have been trapped. To get more details of pairing property of the second disulfide, four model peptides of possible folding intermediates with two disulfides were prepared by protein engineering, and their properties were analyzed. The four model peptides were named [A20-B19, A7-B7]PIP, [A20-B19, A6-B7]PIP, [A20-B19, A6-A11]PIP, and [A20-B19, A7-A11]PIP according to their remaining disulfides. The four model peptides all adopt partially folded structure with moderate conformational differences. In redox buffer, the disulfides of the model peptides are more easily reduced than those of the wild-type PIP. During in vitro refolding, the reduced model peptides share similar relative folding rates but different folding yields: The refolding efficiency of the reduced [A20-B19, A7-A11]PIP is about threefold lower than that of the other three peptides. The present results indicate that the folding intermediates corresponding to the present model peptides all adopt partially folded conformation, and can be formed during PIP refolding, but the chance of forming the intermediate with disulfide [A20-B19, A7-A11] is much lower than that of forming the other three intermediates.     

角蛋白HGTP及其对羊毛发育的影响

羊毛的主要成分是角蛋白,其组分高甘氨酸-酪氨酸蛋白(HGTP)家族成员KAP6、KAP7和KAP8基因表达对羊毛细度和弯曲等特性具有重要影响。本文从羊毛的组成、角蛋白的生物学特征以及HGTP基因定位和表达对细度的影响等方面进行了综述,旨在为羊毛发育调控研究提供理论参考。     

Fast Isolation of Highly Active Photosystem Ⅱ Core Complexes from Spinach

Purification of photosystem Ⅱ (PSII) core complexes is a time-consuming and low-efficiency process. In order to isolate pure and active PSII core complexes in large amounts, we have developed a fast method to isolate highly active monomeric and dimeric PSII core complexes from spinach leaves by using sucrose gradient ultracentrifugation. By using a vertical rotor the process was completed significantly faster compared with a swing-out rotor. In order to keep the core complexes in high activity, the whole isolation procedure was performed in the presence of glycine betain and pH at 6.3. The isolated pigment-protein complexes were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, absorption spectroscopy, 77 K fluorescence spectroscopy and high performance liquid chromatography. Our results show that this method is a better choice for quick and efficient isolation of functionally active PSII core complexes.     

东北山地水生鞘翅目昆虫多样性的比较研究

调查了东北长白山自然保护区及辽宁省医巫闾山两地静水水体中水生甲虫．结果表明,长白山阔叶红松林生态系统水生甲虫比辽宁医巫闾山农林复合生态系统水生甲虫物种丰富的多．长白山水生甲虫共有１７个属２９个种,而辽宁医巫闾山水生甲虫只有１０个属１３个种．两地水生甲虫Ｓｈａｎｎｏｎ多样性指数分别为２．１２４、１．６４３,Ｓｈａｎｎｏｎ均匀度分别为１．２６０、０．６４１,两种不同生态系统中的水生甲虫物种多度分布较好地拟合于对数级数模型,均以少数物种为优势种,其中长白山自然保护区水生甲虫以Ｈｙｄｒｏｇｌｙｐｈｕｓｊａｐｏｎｉｃｕｓ、Ｈａｌｉｐｌｕｓｓｉｍｐｌｅｘ为优势种,辽宁医巫闾山水生甲虫则以Ｈｙｄｒｏｇｌｙｐｈｕｓｐｕｓｉｌｕｓ、Ａｇａｂｕｓｕｓｕｒｉｅｎｓｉｓ、Ａｇａｂｕｓｂｒａｎｄｔｉ占优势．     

蛇毒类凝血酶鼠单克隆抗体的制备

采用杂交瘤技术,获得了４株稳定分泌抗蛇毒类凝血酶的单克隆抗体杂交瘤细胞株,均属ＩｇＧ１ｋ链,４株杂交瘤细胞培养上清液效价为 ４ × １０－１～４ × １０－２,腹水效价为 ４ × １０－１～３．２ ×１０－５。