化脓链球菌中野生型和突变体FtsB蛋白的铁色素结合特性

目的:进一步比较化脓链球菌中野生型和Y137A、W204A突变型FtsB蛋白的铁色素结合特性,确定铁色素结合位点。方法:制备野生型和Y137A、W204A突变型FtsB蛋白,采用ICP-MS和ITC比较其铁色素结合能力;Na2SO4还原实验比较铁色素的还原速率;CD热变性和盐酸胍化学变性实验比较其铁色素结合稳定性。结果:Y137A、W204A突变型FtsB蛋白的铁色素结合能力和结合稳定性均低于野生型蛋白,铁色素的还原速率均高于野生型蛋白,可见Tyr137和Trp204是FtsB蛋白重要的铁色素结合位点。结论:进一步确定了Tyr137和Trp204氨基酸残基在FtsB与铁色素结合中的重要作用,为深入研究细菌中的铁色素转运机理及开发疫苗候选物奠定了一定的理论基础。     

多靶向RNA干扰技术在基因治疗中的应用与前景

RNA干扰(RNA interference,RNAi)通过转录后基因沉默效应特异性抑制靶基因的表达,其沉默机制的高效性、特异性及稳定性使这项技术成为生物医学领域研究基因治疗的重要工具。阐述RNAi技术的特点和RNAi疗法的现状,特别是多靶小干扰RNA(small interference RNA,siRNA)目前的发展态势及其各种结构性修饰,通过使用这些结构修饰的siRNA提高基因沉默的效率,将有助于提高疗效。但该技术在广泛应用于临床之前,仍存在一些亟待解决的问题与面临的挑战,需进一步研究。     

PK-15细胞微载体悬浮培养生产猪细小病毒的工艺研究

通过对猪细小病毒接毒时间TOI、MOI和收毒时间进行优化,开发了一种基于PK-15细胞静置培养的猪细小病毒生产工艺,最大病毒滴度达到107.5TCID50/ml。通过进一步优化接毒时间,成功建立了基于PK-15细胞反应器微载体悬浮培养的猪细小病毒培养工艺,在5L反应器上最大病毒滴度达到107.2TCID50/ml。首次发现乳酸对葡萄糖得率与病毒滴度的正相关性,当猪细小病毒滴度处于最大值时,乳酸对葡萄糖得率也达到最大值,可作为指针病毒滴度及收毒时间的重要参数。     

小球藻用于生物柴油生产的研究进展

目的:对小球藻(Chlorella)生产生物柴油的研究做一综述。方法:查阅近年来国内外小球藻用于生物柴油生产的相关文献,并进行综合分析。结果:微藻生物柴油是具有广泛发展前景的生物柴油,小球藻是目前研究较深入、非常有吸引力的、用于生产生物柴油的微藻藻种,是优质的生物柴油原料,具有其他生物柴油原料不可比拟的优势。随着工程技术的发展和研究的不断深入,探索适宜的小球藻规模化培养方法以期获得质与量兼得的高品质油脂成为研究目标,相信该目标在不久的将来就会实现。结论:小球藻在生物柴油生产领域具有广阔的发展前景。     

骨髓间充质干细胞在脱细胞真皮基质再生过程中的初步研究

较大的腹壁缺损需要应用补片修复来缓解腹横筋膜的张力,人工合成补片的应用一定程度上实现了无张力修补的目的,但它在腹壁外科应用中有诸多的并发症,诸如复发率高,腹腔黏连,肠穿孔导致腹膜炎,侵袭性肠瘘等影响患者术后的正常生活,而脱细胞真皮基质(Acellular dermal matrix,ADM)作为一种新型的生物材料应用在腹壁外科中能解决上述人工合成补片所带来的并发症发挥强大作用且能与周围组织较好的融合,最后改建成宿主自身组织已并在多学科领域中广泛应用;骨髓间充质干细胞(Bone marrow mesenchymal stem cells,BMSCs)能参与组织自我修复,并能分化成为多种功能细胞,分泌各种生长因子,在ADM内源性转归过程中可发挥作用。本文就对骨髓间充质干细胞在ADM生物补片应用于临床疝修补术中转归机制的研究做一综述。     

Valproate Inhibits Methamphetamine Induced Hyperactivity via Glycogen Synthase Kinase 3β Signaling in the Nucleus Accumbens Core

Valproate (VPA) has recently been shown to influence the behavioral effects of psycho-stimulants. Although glycogen synthase kinase 3β (GSK3β) signaling in the nucleus accumbens (NAc) plays a key role in mediating dopamine (DA)-dependent behaviors, there is less direct evidence that how VPA acts on the GSK3β signaling in the functionally distinct sub-regions of the NAc, the NAc core (NAcC) and the NAc shell (NAcSh), during psycho-stimulant-induced hyperactivity. In the present study, we applied locomotion test after acute methamphetamine (MA) (2 mg/kg) injection to identify the locomotor activity of rats received repeated VPA (300 mg/kg) pretreatment. We next measured phosphor-GSK3β at serine 9 and total GSK3β levels in NAcC and NAcSh respectively to determine the relationship between the effect of VPA on MA-induced hyperlocomotor and changes in GSK3β activity. We further investigated whether microinjection of VPA (300 μg/0.5 μl/side, once daily for 7 consecutive days) into NAcC or NAcSh could affect hyperactivity induced by MA. Our data indicated that repeated VPA treatment attenuated MA-induced hyperlocomotor, and the effect was associated with decreased levels of phosphorylated GSK3β at Ser 9 in the NAcC. Moreover, repeated bilateral intra-NAcC, but not intra-NAcSh VPA treatment, significantly attenuated MA-induced hyperactivity. Our results suggested that GSK3β activity in NAcC contributes to the inhibitory effects of VPA on MA-induced hyperactivity.     

Effects of trace element supplementation on the inflammatory response in a rabbit model of major trauma

Patients with a severe trauma exhibit a strong oxidative stress, an intense inflammatory response, and long-lasting hypermetabolism, all of which are proportional to the severity of injury. In this study, we investigated the impact of trace element (TE) supplementation on the inflammatory response in an animal model of major trauma. New Zealand White rabbits were randomly assigned as a control group (n=5) and an experimental group (n=70) that, after receiving a major trauma, was subdivided into Trauma-Control (n=35) and Trauma-TE (n=35) groups. Systemic inflammatory response syndrome (SIRS) was observed in 40 out of 70 rabbits with a trauma, with a higher incidence in the Trauma-Control group (88.6%; 31/35) than the Trauma-TE group (28.6%; 10/35) (p<0.01). The mortality rate was significantly different between the Trauma-Control and the Trauma-TE groups; (34% vs. 8%; p<0.01).There were significant post-trauma alterations in the levels of (1) serum and spleen zinc (Zn), copper (Cu), selenium (Se), and manganese (Mn), (2) serum AST and ALT, (3) serum interleukin-6/10, and (4) nuclear factor kappa binding (NF-κB) activity and the expression. TE supplementation: (1) improved blood urea nitrogen (BUN), and creatinine (Cr) levels, (2) stabilized IL-6/10 production, (3) decreased NF-κB p⁶⁵ production. Appropriate TE supplementation can improve the TE status, mitigate SIRS, and reduce the mortality due to multiple organ dysfunction syndromes (MODS)/multiple organ failure (MOF) after major trauma.     

太湖粳稻同名地方品种的遗传差异

选用45个SSR标记分析太湖流域荔枝红、老来青、太湖青和老虎稻共4组粳稻同名地方品种的遗传差异。结果表明:同名地方品种平均Nei遗传距离为0.120~0.171,遗传同一性程度较高,其中有8对同名品种难以区别,但多数品种仍然存在一定的遗传变异,且个别品种差异较大;同名品种遗传差异与种质来源、品种名称的近似程度没有关系。     

国外引进亚麻种质资源的聚类分析及评价

通过对国外引进的150份亚麻种质资源的农艺性状鉴定与聚类分析研究,将其分为4个类群。各个类群具有不同的特点,其中类群Ⅰ表现为株高较高、抗倒伏能力差、出麻率高、产量较高;类群Ⅱ株高较矮、较抗倒伏、出麻率较低、产量较低;类群Ⅲ表现为高抗倒伏、抗白粉病、产量较低;类群Ⅳ株高和产量最高。不同类群在育种中有不同的利用价值,尤其类群Ⅲ和Ⅳ中有高抗及高产材料,具有十分重要的利用价值。     

固本颗粒胶囊对大鼠COPD模型血清IL-8及TNF-α影响的实验研究

目的:根据COPD慢性气道炎症学说,探讨固本颗粒胶囊对COPD模型大鼠血清中相关细胞因子的影响,从而阐明其防治COPD的作用机理,为固本颗粒胶囊的临床应用提供实验依据.方法:将50只Wistar大鼠随机分成正常对照组、模型对照组、强的松组、固本颗粒胶囊低剂量组、固本颗粒胶囊高剂量组,每组10只,以烟熏及气管内滴注脂多糖的方式建立大鼠COPD模型,予相应药物干预,观察记录大鼠一般状况,至实验结束,酶联免疫吸附法检测大鼠血清中相关细胞因子(IL-8、TNF-α)的含量.相关实验数据用SPSS10.0统计软件进行统计学处理.结果:大鼠一般状况及组织病理学改变提示COPD模型复制成功,与正常对照组比较,模型对照组大鼠血清中相关细胞因子(IL-8、TNF-α)的含量水平失衡.在改善COPD模型大鼠的一般状况、病理学改变及细胞因子含量比例失衡的作用结果来看,各治疗组与模型对照组均有显著差异(P＜0.05).综合比较,强的松组治疗作用最为显著,固本颗粒高剂量次之,固本颗粒低剂量组作用最弱.结论:①.固本颗粒胶囊能有效缓解COPD模型大鼠临床表现及气道炎症,其作用机制在于:能纠正COPD大鼠体内细胞因子水平失衡;②.上述作用,具有一定的量效关系,即随着给药剂量的增加有加强趋势.