三七总皂苷对脑缺血再灌注大鼠神经血管单元超微结构的影响

为了观察脑缺血再灌注(cerebral ischemia reperfusion, CIR)大鼠缺血灶周边脑组织不同时间点神经血管单元(neurovascular unit, NVU)超微结构变化,研究三七总皂苷(Panax notoginseng saponins, PNS)对脑缺血再灌注大鼠脑组织NVU超微结构的影响,本研究采用改良Zea Longa法制作局灶性大脑中动脉闭塞(MCAO)模型,缺血2 h后再灌注;采用Longa法评分标准检测各组大鼠术后4 h神经功能评分,随之各组进行干预,分别在缺血再灌注后24 h、72 h、7 d、3周进行神经功能评分和透射电镜下观察各组大鼠缺血灶周边脑组织的NVU超微结构变化。研究结果表明,干预前即术后4 h治疗组和对照组神经功能评分比较无明显差异;PNS干预后治疗组大鼠神经功能评分逐渐改善,缺血再灌注后24 h与对照组比较,差异无统计学意义(p>0.05),再灌注72 h、7 d、3周的大鼠神经缺损评分与同时间点对照组相比差异具有统计学意义(p<0.05)。电镜观察发现再灌注24 h、72 h、7 d、3周治疗组大鼠脑组织NVU超微结构的病理形态损伤均较同时间点对照组明显减轻。本研究结论认为,PNS通过整合促进脑缺血后NVU的神经元、胶质细胞和微血管的修复,改善神经功能缺损症状,对脑缺血具有保护作用。     

三七总皂苷对大鼠脑缺血再灌注损伤后脑组织的凋亡抑制作用

目的:探讨三七总皂苷(PNS)对大鼠脑缺血再灌注损伤后大脑皮层细胞的凋亡抑制作用.方法:采用大脑中动脉栓塞再通法建立脑缺血再灌注模型,将大鼠随机分为假手术组、缺血再灌注组和三七总皂苷治疗组;根据再灌注时间不同分为再灌注10h、12 h、24h组,缺血时间为90 min.大鼠脑缺血再灌注10h、12h和24h不同时间点进行神经功能评分,采用原位末端标记法检测神经细胞凋亡情况,同时用免疫组化法检测抑制凋亡蛋白XIAP和促凋亡蛋白Smac阳性细胞数.结果:缺血再灌注组神经细胞凋亡数明显增加,XIAP蛋白的表达呈先高后低的变化(P＜0.05),Smac蛋白的表达明显上升(P＜0.05);PNS治疗组能明显减少脑皮层组织神经细胞凋亡数(P＜0.05),增加XIAP蛋白表达(P＜0.05),减少Smac蛋白表达(P＜0.05).结论:PNS可能通过促进抑制凋亡蛋白XIAP的表达和抑制促凋亡蛋白Smac的表达,减少脑组织缺血再灌注损伤后的神经细胞凋亡,进而对再灌注后脑组织具有抑制脑细胞凋亡的作用.     

大鼠局灶性脑缺血再灌注损伤中iNOS在大脑皮层和海马的表达

目的研究局灶性脑缺血再灌注损伤中iNOS在不同脑区的表达.方法用改良的血管内栓线技术制造大鼠局灶性脑缺血与再灌注模型,应用免疫组织化学技术检测脑组织中的iNOS的表达.结果 (1)脑缺血再灌注损伤24h后,缺血组缺血侧大脑皮层、海马CA1区、CA3区神经元iNOS的表达显著增强,与正常对照组比较有显著性差异(P<0.05);(2)脑缺血再灌注损伤24h后,缺血组对照侧大脑皮层、海马CA1区、CA3区神经元iNOS的表达也明显增强,与正常对照组比较有显著性差异(P<0.05);(3) 与对照侧比较,脑缺血再灌注大鼠缺血侧皮质的iNOS表达显著增强(P<0.05),而海马CA1区、CA3区缺血侧的iNOS表达与对照侧相比无显著性差异(P>0.05).结论局灶性脑缺血再灌注损伤后,缺血侧皮层和海马iNOS表达显著升高,未缺血脑区(对照侧)iNOS反应性也较对照组者升高.     

三七总皂苷对缺血再灌注损伤后大鼠脑组织的MDA、GSH-PX表达的影响

目的:探讨三七总皂苷(PNS)对缺血再灌注损伤后大鼠大脑皮层组织丙二醛(MDA)的含量、谷胱甘肽过氧化物酶(GSH-PX)的活性的影响.方法:采用线栓法制备大鼠大脑中动脉局灶缺血再灌注模型,选用Wistar雄性大鼠(54只)随机分成3组,即:假手术组(12只)、缺血再灌注组(24只)、三七总皂苷治疗组(18只);再根据灌注时间不同分为再灌注l0h、12h、24h组,每组是8只.缺血时间为90min.各组动物给药方法:三七总皂苷治疗组(PNS组)腹腔注射1％PNS(50mg/kg),每天一次,持续10天;假手术组和缺血再灌注模型组腹腔注射与PNS组等体积的生理盐水10天,各组于术前1h再注射1次.进行HE染色观察脑皮层组织形态病理学变化;硫代巴比妥酸比色法检测MDA的含量;二硫双硝基苯甲酸法检测GSH-PX的活性.结果:缺血再灌注组GSH-PX的活性降低(P＜0.05),MDA的含量升高(P＜ 0.05);PNS治疗组GSH-PX的活性明显增强(P＜0.05),MDA的含量明显下降(P＜0.05).结论:PNS可能通过增加GSH-PX的活性和减少MDA的含量来拮抗缺血再灌注损伤后脑组织的脂质过氧化,发挥脑组织的保护作用.     

三七皂苷Rg1对大鼠脑缺血再灌注损伤海马部位保护作用机制的研究

本文探讨三七皂苷Rg1对局灶性脑缺血再灌注损伤大鼠海马部位的脑源性神经营养因子(brain-derivedneurotrophic factor,BDNF)阳性蛋白的含量和阳性神经元数目是否具有上调作用。实验结果表明三七皂苷Rg1高、中、低剂量组和阳性对照组均能明显改善脑缺血的神经缺失症状,并能上调大鼠脑缺血再灌注损伤海马部位的BDNF阳性蛋白的含量和阳性神经元数量(P<0.05);与阳性对照组(尼莫地平1 mg/kg)相比,用药7 d时,Rg1中剂量组(100 mg/kg)在改善脑缺血的神经缺失症状以及上调大鼠脑缺血再灌注损伤海马部位的BDNF阳性蛋白的含量和阳性神经元数量方面,作用上强于尼莫地平(P<0.05)。三七皂苷Rg1能上调BDNF阳性蛋白的表达,通过BDNF对脑缺血再灌注神经元损伤所起的保护作用,从而发挥其对脑缺血的治疗作用,这可能是三七皂苷Rg1对脑缺血保护作用的机制之一。     

促红细胞生成素对大鼠局灶性脑缺血再灌注神经元的保护作用及P53蛋白的表达

目的:探讨促红细胞生成素(Epo)对大鼠局灶性脑缺血再灌注神经细胞的保护作用.方法:60只SD大鼠随机分为缺血再灌注Epo治疗组(又分为高剂量A组、低剂量B组)、缺血再灌注组(C组)及假手术组(D组),采用大脑中动脉线栓法制备大鼠局灶性脑缺血再灌注模型.参考Longa的5分制法在大鼠麻醉清醒后进行评分,TTC染色法观察线栓侧的梗死体积,并检测脑组织含水量的变化,HE染色法观察脑缺血再灌注后脑组织的病理变化,TUNEL法观察神经细胞凋亡情况,western blot法观察p53蛋白的表达变化.结果:对照组比较,大鼠脑缺血再灌注后出现不同程度的脑梗死,24h后缺血中心区及周围区均可见到p53蛋白表达.缺血再灌注6h内给予Epo可显著改善大鼠神经功能评分,减少梗死体积及脑组织含水量,减轻病理学变化及神经细胞凋亡.结论:Epo通过调控神经细胞凋亡、改善缺血再灌注损伤而发挥脑保护作用,P53蛋白参与缺血再灌注后神经细胞凋亡机制.     

骨髓间充质干细胞治疗脑梗死

目的:研究骨髓间充质干细胞(MSC)对大鼠脑缺血再灌注损伤的治疗机制。方法:20只Wistar大鼠随机分为对照组和MSC治疗组。应用GFP阳性MSC,再灌注1d后经尾静脉注射MSC(1×106),对照组则注射PBS。采用线栓法建立脑缺血再灌注模型。术后每天由双盲于试验组的研究人员应用爬杆计分法评定大鼠神经功能。缺血2h再灌注8d取脑组织,用免疫组织化学方法检测脑组织中bFGF的表达。结果:MSC治疗组大鼠的神经功能缺损评分明显低于手术组和对照组(P<0.05)。MSC治疗组缺血侧缺血周边区脑组织中观察到GFP阳性与bFGF免疫组化染色阳性细胞。结论:经尾静脉给予的MSC可促进脑缺血再灌注大鼠的运动功能恢复;bFGF表达升高,可能是MSC脑保护作用机制之一。     

PEP-1 超氧化物歧化酶对大鼠脑缺血再灌注后Bcl-2 的影响

目的:观察细胞穿透肽-铜,锌超氧化物歧化酶(PEP-1-SOD1)预处理对大鼠局灶性脑缺血再灌注损伤的改善作用及其脑保护机制。方法:线栓法建立大鼠局灶性脑缺血6h后再灌注损伤模型,进行神经行为评分,并通过HE染色在光镜下观察神经细胞损伤变化,免疫组化法检测B细胞淋巴瘤基因-2(B-cell lymphoma-2,Bcl-2)蛋白的阳性表达。结果:盐水对照组(缺血再灌注组或模型组)神经障碍显著高于假手术组(P<0.05),与模型组相比,PEP-1-SOD1预处理组可降低神经障碍评分(P<0.05);光镜下,假手术组神经细胞结构正常,PEP-1-SOD1预处理组和缺血再灌注组均有不同程度的缺血再灌注损伤,PEP-1-SOD1预处理组较缺血再灌注组损伤轻;假手术组Bcl-2蛋白表达极弱,缺血再灌注组和PEP-1-SOD1预处理组在脑缺血再灌注后6h在缺血半暗带周围出现Bcl-2蛋白阳性表达,24h达到高峰,48h表达开始减少。与假手术组相比,PEP-1-SOD1预处理组和缺血再灌注组Bcl-2蛋白阳性细胞数显著增多(P<0.05);与缺血再灌注组相比,PEP-1-SOD1预处理组Bcl-2蛋白阳性细胞数显著增多(P<0.05)。结论:PEP-1-SOD1对大鼠局灶性脑缺血再灌注损伤有保护作用,PEP-1-SOD1可通过上调Bcl-2蛋白的表达发挥脑保护作用。     

缺血预适应对小鼠脑缺血再灌注损伤模型血脑屏障的保护作用及机制

目的:通过研究缺血预适应对小鼠脑缺血再灌注损伤血脑屏障通透性的影响,探讨缺血预适应的脑保护作用及相关分子机制。方法:取清洁健康成年小鼠72只,随机分为脑缺血预适应组(brain ischemic precondition,BIP),脑缺血再灌注组(middle cerebral artery occlusion and reperfusion,MCAO/R)和假手术组(sham group),每组均24只,采用zealonga线栓法栓塞小鼠大脑中动脉建立BIP模型和MCAO/R模型,通过氯化三苯基四氮唑(triphenyl tetrazolium chloride,TTC)染色计算脑梗死面积,改良神经功能缺损评分(modified neurological severity scores,m NSS)对脑缺血再灌注神经损伤程度进行评估,测干-湿重法以及伊文氏蓝(Evans blue,EB)示踪结合脑组织EB定量法评价血脑屏障(blood brain barrier,BBB)的损伤程度,采用免疫组化法检测各组脑组织低氧诱导因子-1α(HIF-1α)和血管内皮生长因子(VEGF)的表达。结果:与MCAO组相比,BIP组显著降低缺血再灌注后m NSS评分,缩小了梗死面积并减轻脑水肿,有效的保护BBB功能,BIP组再灌注24 h时脑梗死灶周围皮质区HIF-1α及VEGF的表达均明显上调,差异有统计学意义(P0.05)。结论:BIP对小鼠脑缺血再灌注损伤模型BBB有一定的保护作用,其机制可能与其诱导HIF-1α及VEGF的表达上调有关。     

UCF-101对大鼠局灶性脑缺血再灌注后JNK和ERK活性的影响

目的:探讨UCF-101对局灶性脑缺血再灌注大鼠脑内c-Jun氨基末端激酶(JNK)和胞外信号调节酶(ERK)活性的影响,进一步探讨UCF-101对局灶性脑缺血再灌注损伤脑保护作用的机制。方法:采用大脑中动脉线栓法(MCAO)建立大鼠局灶性脑缺血再灌注模型,随机分为假手术组,缺血再灌注组,UCF组,应用TTC检测大鼠脑梗死体积,TUNEL法检测神经元凋亡,Western blot检测ERK和JNK的活性。结果:UCF-101可下调脑缺血再灌注大鼠脑组织JNK蛋白的活性,上调ERK蛋白的活性,并降低梗死体积、坏死和凋亡细胞数。结论:UCF-101对大鼠局灶性脑缺血再灌注损伤有保护作用,抑制JNK凋亡通路、促进ERK生存通路,从而减轻细胞凋亡是其脑保护机制之一。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.