射干幼茎愈伤组织及试管苗培养的研究

为保护野生资源,以射干幼茎为材料,应用植物组织培养技术,进行了愈伤组织培养、愈伤组织分化培养、试管苗培养和试管苗的移栽与定植的研究。结果显示,幼茎段培养愈伤组织的适宜培养基是MS+琼脂5.3 g·L-1+蔗糖38 g·L-1+2,4-D2.2 mg·L-1+6-BA 0.8 mg·L-1;愈伤组织分化无根苗培养的适宜培养基是1/2MS+琼脂5.3 g·L-1+蔗糖42 g·L-1+NAA0.05 mg·L-1+6-BA 1.4 mg·L-1;试管苗培养的适宜培养基是1/4MS+蔗糖10 g·L-1+琼脂5.3 g·L-1+IBA0.05 mg·L-1+IAA0.25 mg·L-1;试管苗移栽成活率为90.3%;定植成活率为96.0%。定植试管苗翌年正常开花结果,野生的射干的植物性状保持不变。     

基于数学形态学的香梨果梗提取方法

果梗是香梨品质分级的重要指标之一。本文在香梨图像经过背景分割和边缘检测获取边缘图像后,提出一种利用数学形态学方法对香梨果梗进行自动提取的新方法。利用MATLAB 7.1软件平台开发了香梨果梗自动提取的计算机视觉检测软件。研究结果表明,该方法对香梨果梗的提取的正确率为90.7%。     

三七总皂苷对新生大鼠海马神经干细胞活性影响及促分化作用

目的研究三七总皂苷对海马神经干细胞活性的影响和分化作用。方法体外培养海马神经干细胞,分别接种于96孔板和12孔板,96孔板细胞按三七总皂苷不同浓度梯度和同一浓度的不同时间点进行干预,应用MTT法检测海马神经干细胞的OD值,观察三七总皂苷对海马神经干细胞活性的影响;12细胞孔板分为对照组和给药组,应用免疫荧光染色方法检测神经元新生特异抗原（Tuj-1）和胶质细胞新生抗原（Vimentin）的表达,以观察三七总皂苷对海马神经干细胞分化的影响。结果（1）一定浓度范围内三七总皂苷能增强海马神经干细胞活性;（2）三七总皂苷能促进海马神经干细胞向神经元和胶质细胞方向分化。结论三七总皂苷能增强海马神经干细胞的活性并能促进海马神经干细胞分化。     

Restoration of rat calvarial defects by poly（lactide-co-glycolide）/ hydroxyapatite scaffolds loaded with bone mesenchymal stem cells and DNA complexes

A composite construct comprising of a bone mesenchymal stem cell (BMSC) sheet, plasmid DNA, encoding human bone morphogenic protein-2 (hBMP-2), and poly(lactide-co-glycolide)/hydroxyapatite (PLGA/HA) sponge was designed and employed in the restoration of rat calvarial defects. To improve gene transfection efficiency, a cationic chitosan derivative, N,N,N,-trimethyl chitosan chloride (TMC), was employed as the vector. The TMC/DNA complexes had a transfection efficiency of 13% in rat BMSCs, resulting in heterogeneous hBMP-2 expression in a 10-d culture period in vitro. In vivo culture of the composite constructs was performed by implantation into rat full-thickness calvarial defects, using constructs lacking pDNA-hBMP-2 or BMSC sheets as controls. Significantly higher heterogeneous expression of hBMP-2 was detected in vivo at 2 weeks for the cell sheet/DNA complex/scaffold constructs, compared with the constructs lacking pDNA-hBMP-2 or BMSC sheets. New bone formation was evident as early as 4 weeks in the experimental constructs. At 8 weeks, partial bridging of calvarial defects was observed in the experimental constructs, which was significantly better than the constructs lacking pDNA-hBMP-2 or BMSC sheets. Therefore, the combination of the PLGA/HA scaffold with BMSC sheets and gene therapy vectors is effective at enhancing bone formation.     

现代生物技术应用于医药及生殖生物学领域的研究

论述了现代生物技术应用于医药及生殖生物学领域研究取得的新成果与新进展,包括基因治疗、基因工程药物开发及干细胞应用于生殖生物学领域,对这些新成果进行了评述,展望了其未来发展。     

干细胞移植引发的伦理思考暨解决之道

干细胞移植对再生医学的发展有重要意义,但围绕胚胎干细胞的研究也产生了许多道德争论。涉及胚胎干细胞来源的伦理争议主要包括胚胎有无生命、道德地位等;干细胞的实际应用中的伦理问题主要包括会不会损害提供者的隐私权等。我国迫切需要建立符合国情的政策法规体系,包括制定更为完善的法律来限制和监管干细胞移植的临床治疗,对医院和医生的手术资格和能力进行审查,成立专门委员会对医疗事故进行责任鉴定等。     

外源性干细胞因子对糖尿病胃轻瘫大鼠胃窦Cajal细胞的影响

目的探讨外源性干细胞因子（SCF）能否改善糖尿病胃轻瘫（DGP）大鼠胃窦Cajal细胞（ICC）的异常病变。方法sD大鼠随机分为实验组和对照组，实验组腹腔注射链脲佐菌素（STZ）50mg／kg并高糖高脂饲料不规律喂养构建DGP模型，对照组腹腔注射等量生理盐水并普通饲料规律喂养。成模后随机分为糖尿病组（DM组）、糖尿病＋外源性干细胞因子治疗组（DM＋SCF组）；DM＋SCF纽腹腔注射SCF0．4ug／（kg·d），共15天，对照组和DM纽每天腹腔注射等量的磷酸盐缓冲液（pH=7．4）。RT-PCR、Wester Dblot检测胃窦组织中SCF及c—kit的mRNA及蛋白表达；免疫组化、透射电镜观察胃窦组织中Cajal细胞的变化。结果DM组大鼠胃窦组织SCF及c—kit的mRNA及蛋白表达下降，Cajal细胞数量减少，细胞内线粒体肿胀、内质网扩张；予外源性SCF干预后，胃窦组织中SCF及C—kjf的mRNA及蛋白表达上调，caial细胞数量增多、超微结构明显改善。结论外源性SCF能在一定程度上改善或逆转糖尿病胃轻瘫大鼠胃窦Cajal细胞的异常病变：     

Induction-dependent neural marker expression and electrophysiological characteristics of bone marrow mesenchymal stem cells that naturally express high levels of nestin

Under certain experimental conditions, bone marrow mesenchymal stem cells (MSCs) express neuronal phenotypes and neuronal markers, which suggests that they could be used to treat various neurological diseases. In the present study, MSCs were isolated from adult rat bone marrow, cultivated, and evaluated for neurotrophin expression profiles, as well as the potential to differentiate into functional neuronal-like cells in vitro. MSCs from passage 5 were pre-induced with DMEM/F12 medium containing 10% fetal bovine serum (FBS) and 10 ng/mL bFGF (fibroblast growth factor-2). Subsequently, a chemical inductor containing Dimethyl Sulphoxide (DMSO), Butylated Hydroxyanisole (BHA) and forskolin were used to induce neural expression of MSCs. Expression patterns of nestin, NF-200, and GFAP at time points before and after induction were detected by immunofluorescence. Nerve Growth Factor (NGF), brain-derived neurotrophic factor (BDNF) expressions in MSCs were evaluated by RT-PCR. The whole-cell patch clamp technique was utilized to elucidate the electrical behavior of MSC before and after 24-h differentiation induction. Immunofluorescence analysis revealed that MSCs expressed nestin (57.1% ± 6.9%), but not NF-200 or GFAP. Following neural induction, the cells exhibited a neuronal-like appearance. Nestin and NF-200 expression was positive in the neuronal-like cells, but GFAP expression was negative. After 6-, 12- and 24-h induction, the ratio of nestin-positive cells was 96.5% ± 1.9%, 88.1% ± 5.4%, and 33.5% ± 5.4%. NF-200 positive cells were 90.1% ± 2.9%, 97.5% ± 1.3%, and 98.1% ± 1.6%, respectively. However, prior to induction, MSCs already expressed NGF and BDNF. With a stimulus impulse of 40 mV, the density of the transient outward K current was (9.95 ± 4.85) pA/pF (n = 9) and (328.50 ± 30.62) pA/pF (n = 9) before and after induction, and the density of transient calcium ion currents was (−0.059 ± 0.027) pA/pF (n = 7) and (−6.66 ± 0.50) pA/pF (n = 7), respectively. Transient outward potassium currents and calcium ions currents gradually increased following induction. In addition, MSCs isolated from bone marrow exhibited characteristics of neuronal progenitor cells and expressed neurotrophins. These cells exhibited the capacity to differentiate into functional neuronal-like cells in vitro. These results suggested that MSCs express high levels of nestin and could be utilized for therapeutic strategies to treat nervous system diseases.     

人干细胞生长因子的克隆与表达

干细胞生长因子能够刺激激造血干细胞生长，并与多种细胞因子有协同作用。研究中，运用ＰＣＲ手段，从中国人胎肝ｍＲＮＡ中扩增得到编码人ＳＣＦ全部胞外部分的ｃＤＮＡ。经测序鉴定后，将其克隆人表达载体ｐＲＳＥＴ－Ｃ，并在大肠杆菌ＤＥ３菌株进行表达。     

柠条锦鸡儿不同部位茎段水力结构特征的比较研究

比较荒漠植物柠条锦鸡儿不同部位茎段的水力结构特征.研究表明：随着茎木质部横截面面积增大,柠条锦鸡儿的胡伯尔值、比导率和叶比导率增加.柠条锦鸡儿存在着水分运输的限速区;限速区胡伯尔值高于非限速区,比导率和叶比导率低于非限速区.柠条锦鸡儿的水分运输主要受到分叉区（限速区）和枝条末端的细枝限制.