嗅球成鞘细胞的分离培养与鉴定

目的:探讨一种获取高纯度嗅球成鞘细胞(olfactory ensheathing cells,OECs)的方法.方法:从新生SD大鼠(3d)嗅球中迅速分离嗅神经层和嗅颗粒层,采用酶消化法分离细胞,差速贴壁法纯化细胞,接种于多聚赖氨酸包被的培养板内培养2d,采用NGFRp75和S100蛋白双标免疫组化、以Hoechst33342复染鉴定OECs的纯度.结果:OECs的纯度为(95.64±2.76)%.结论:本法是一种相对简便易行且经济、稳定、有效的OECs分离方法.     

农田林网条件下大斑啄木鸟夏季和冬季日间行为模式

2005年7月至2008年1月,利用目标动物取样法对内蒙古乌拉特前旗地区农田林网中大斑啄木鸟(Picoides major)夏季和冬季的日间行为模式进行了分析.结果发现,大斑啄木鸟不同行为的活动次数差异极为显著,主要活动是觅食啄食;夏季具午间休息习性,日间行为节律明显,而冬季没有午休习性,日问行为节律不明显;不同性别大斑啄木鸟之间的日间行为差异不显著,但大斑啄木鸟在不同季节的日间行为差异极为显著,夏季活动时间明显长于冬季.     

一例疑似黏膜病死亡麋鹿消化及主要免疫器官病理组织学观察

应用常规石蜡切片,H.E染色,对临床初步诊断为黏膜病的一例死亡麋鹿(Elaphodus davidianus)的消化系统及脾、淋巴结进行病理组织学观察。结果表明,消化道的病变主要在黏膜层,黏膜上皮细胞脱落、坏死,固有层内毛细血管充血,炎性细胞浸润;脾主要表现为急性败血型,红髓充血、出血严重,白髓几乎完全消失;淋巴结坏死严重,组织结构被破坏,界限不明显,仅见淋巴细胞弥漫性分布于整个淋巴结内。病理组织学观察为临床诊断提供了形态学依据。     

粪肠球菌精氨酸脱亚胺酶酶学性质研究

经硫酸铵分级沉淀、Q-Sepharose Fast Flow阴离子交换层析、SephadexG-75凝胶柱层析从NJ402自溶细胞超声破碎液中提纯得到精氨酸脱亚胺酶(ADI),纯化倍数为34.5,活力回收率为31.4%,经SDS-PAGE以及Native-PAGE测定结果表明,ADI亚基分子量约为46 kD,该酶非变性情况下的分子量约为190 kD左右,该酶为同四聚体结构.酶学,胜质研究结果表明:ADI催化最适温度和最适pH分别为50℃和6.5,在45℃以下和pH 5～8之间有很好的稳定性.ADI是L-型脱亚胺酶,具有严格的光学选择性,适当浓度的Mn2 、Mg2 、Co2 对ADI催化活力的促进作用较大,高浓度的Zn2 和Co2 对酶有一定程度的抑制作用,L-瓜氨酸对酶无抑制作用而L-鸟氨酸却表现出较强的抑制作用.ADI在最佳催化条件下作用于L-精氨酸的米氏常数为3.2686 mmol/L,最大反应速度为2.44 μmol/min.     

土壤微生物RAPD分析体系的优化研究

采用正交实验设计,对影响土壤微生物RAPD扩增体系的Mg2+、dNTP浓度及引物浓度进行了研究,同时对退火温度、延伸时间及循环次数进行摸索。结果表明,适宜土壤微生物PCR扩增反应在25μl体积中进行,包括7ng土壤微生物DNA样品、20pm随机引物l、.5uTaq酶、3.0mmol.L-1Mg-CL2和0.2mmol.L-1dNTP。PCR扩增反应进程如下:94℃3min,使土壤DNA变性;然后再进行39个循环,每个循环包括94℃1min,37℃40s,72℃90s,结束后72℃延伸7min。     

Promotive Effect of Low Concentrations of NaHSO3 on Photophosphorylation and Photosynthesis in Phosphoenolpyruvate Carboxylase Transgenic Rice Leaves

Spraying a 1-2 mmol/L solution of NaHSO3 on the leaves of wild-type rice (Oryza sativa L.)Kitaake (WT), phosphoenolpyruvate carboxylase (PEPC) transgenic (PC) rice and PEPC phosphate dikinase(PPDK) transgenic rice (PC PK), in which the germplasm was transformed with wild-type Kitaake as the gene receptor, resulted in an enhancement of the net photosynthetic rate by 23.0%, 28.8%, and 34.4%,respectively, for more than 3 d. It was also observed that NaHSO3 application caused an increase in the ATP content in leaves. Spraying PMS (a cofactor catalysing the photophosphorylation cycle) and NaHSO3 separately or together on leaves resulted in an increase in photosynthesis with all treatments. There was no additional effect on photosynthetic rate when the mixture was applied, suggesting that the mechanism by which NaHSO3 promotes photosynthesis is similar to the mechanism by which PMS acts and that both of compounds enhanced the supply of ATE After spraying a solution of NaHSO3 on leaves, compared with the WT Kitaake rice, a greater enhancement of net photosynthetic rate was observed in PEPC transgenic(PC) and PEPC PPDK transgenic (PC PK) rice, with the greatest increase being observed in the latter group. Therefore ATP supply may become the limiting factor that concentrates CO2 in rice leaves transformed with an exogenous PEPC gene and exogenous PEPC PPDK genes.     

Causes and Consequences of Changes in Nutrient Structure in the Jiaozhou Bay

Concentrations and ratios of nutrients in Jiaozhou Bay, China, have changed much in the past decades, with trends indicating an increase in nitrogen and a decrease in silicate. Statistical analysis has shown that the long-term variations of nutrients are associated with agricultural activities, precipitation, and anthropogenic factors. Stoichiometric calculations indicate that the nutrient structure has become more and more unbalanced. There has been almost no possibility for nitrogen limitation since the 1980s, the probability of P limitation has increased, and the probability of Si limitation has also increased markedly from the 1980s to the 1990s. As a consequence of changes in nutrient structure, a decrease in the abundance of net phytoplankton was evident, whereas total chlorophyll a levels have remained roughly unchanged at around 3.55 μg/L. Thus, it is likely that smaller species have taken the niche vacated by the larger species. Changes in phytoplankton size and species composition may ultimately lead to various functional and structural changes at the system level.     

海洋生物多糖的研究与发展

多糖具有多种生理功能,随着陆地资源的消耗,海洋生物多糖的作用逐渐被发现,它不仅具有明显的生物学活性,而且无毒副作用,该将主要从海洋生物多糖的生物学活性及研究现状进行简述。     

可溶性TRAIL蛋白的高密度培养及补料策略研究

采用分批补料的方法高密度培养重组大肠杆菌C600/PbvTRAIL制备人可溶性TRAIL蛋白,优化发酵工艺,探索简单高效的分离纯化方法并测定蛋白生物活性。通过比较几种不同的补料策略：间歇流加、Dostat、pHstat,摸索了一种流加策略,即DOstatpHstat组合流加,有效的避免了发酵过程中,尤其是诱导表达阶段乙酸积累的增加,使TRAIL蛋白在高密度培养条件下,得到高效表达。菌体密度最终达到300g/L（WCW）以上,可溶性TRAIL蛋白占菌体总蛋白的4.2%,含量为1.1g/L。在整个发酵过程中,乙酸浓度接近于0,且未使用任何特殊手段,如纯氧、加压等,简化了发酵工艺,降低了发酵成本,为TRAIL的工业化生产创造了条件。     

水生细菌生物量的估算方法*

细菌的生物量是海洋微生物研究的关键参数之一。目前,细菌生物量估算方法主要根据其体积的大小进行换算,但换算的方式也不尽一致。对细菌体积和细菌碳含量主要的测定方法、体积与生物量之间换算系数、换算模式进行介绍,评述。认为流式细胞术是测定细菌体积较为合适的方法,X-射线微量分析法是测定单个细菌生物量(碳含量)最合适的方法,异速生长模式是目前生物量换算过程较为常用的模式。