钙调素抑制剂对转板藻细胞骨架的影响

转板藻细胞经钙调素抑制剂处理后,按Pena简易快速考马斯亮蓝法染色,观察到抑制剂不但抑制叶绿体的转动,而且使微丝结构发生明显凝集。其作用与细胞松弛素B(cytochalasinB)类似,高pH液使其消失,秋水仙素无明显作用。而未经抑制剂处理的细胞,其叶绿体端部呈现出刷样丝束结构。     

细胞排核的扫描电镜观察

本文借扫描电镜术比较了秋水仙素、细胞松弛素B(CB),以及这两种化合物并合作用下人肝癌BEL-7402系细胞表面形态学的差异。结果表明,秋水仙素与CB诱发细胞排核的模式迥然各异,证实了我们先前在光镜水平上的观察:前者可使排出的核体具有独自游走的能力,甚至完全脱离胞质体而移向外缘;而后者则无这种效应。若并合这两种因子处理细胞,胞质体裂解成大小不等的球状结构。此外,细胞表面微绒毛的变化与CB有关而与秋水仙素的作用无关。文内对细胞骨架与细胞排核及细胞运动的关系作了简要的讨论。     

细胞分裂阻滞剂对大蒜根尖细胞周期的影响

植物的根尖具有分裂能力强、结构简单、取材方便、便于药剂处理等特点,因此成为研究细胞分裂、分化和离体培养的常用材料。秋水仙素和细胞松弛素B对细胞分裂过程中微管、微丝的作用以及对细胞核DNA复制的影     

一种抗不同类型中等纤维的混合型兔自发抗体

本文报道了存在于未免疫家兔血清中的一种自发抗体(SRI)。使用间接免疫荧光法,这种自发抗体能在鸡肌原纤维上染出-线和Z-盘,在CHO细胞和HeLa细胞中能染出不同排列式样的胞质纤维结构。在秋水仙素处理的CHO细胞中,SRI血清仅能染出具有典型凝聚式样的波形纤维。而在秋水仙素处理的:HeLa细胞中,SRI血清同时能染出对秋水仙素不敏感的前角质蛋白纤维和对该药敏感的波形纤维。细胞松弛素B处理和Trito X-100抽提对:HeLa细胞的纤维染色无影响。根据所染纤维的特征,我们认为SRI自体免疫抗血清是一个至少含有抗前角质蛋白抗体和抗波形纤维蛋白抗体的混合抗体。     

微细胞(microcell)的制备及其生物学特性

本文比较了单纯用秋水酰胺(1μg/ml)和秋水酰胺(1μg/ml)加细胞松弛素B(1μg/ml)复合处理体外培养的细胞株的微细胞生产率,发现后一种方法大大提高了微细胞的获得率。对于微核化细胞的离心脱核方法以及粗制的微细胞纯化方法亦作了改进。同时研究了微细胞的存活时间以及它的大小等生物学特性。并且研究了CHO Wg3-h SL7 HFC四种细胞在秋水仙胺和秋水仙胺加细胞松弛素B复合处理后的微核率,发现后一种方法能促进细胞的微核化,但不同的细胞株对这两种有丝分裂阻断剂敏感性差异很大,体外未经转化的人的正常成纤维细胞对有丝分裂阻断剂的敏感性与细胞年龄有密切关系,越年轻越敏感。     

去核过程中CHO细胞波形纤维的分布

本文用豚鼠抗小牛晶状体波形纤维蛋白的血清抗体,对经细胞松驰素B(CB)和秋水仙素等药物处理后再离心去核的CHO细胞及其核体、胞质体进行了间接免疫荧光染色,并对核体做了电镜观察。CB处理后离心的细胞的免疫荧光染色显示,去核过程中核的后方始终伴有强烈的荧光,核体上也有强荧光斑。在核体的电镜材料中同样观察到了中等纤维。经CB和秋水仙素合并处理后离心的细胞,去核效果比仅用CB处理有明显的增强,免疫荧光染色表明,核后的荧光并不因秋水仙素处理而消失。实验结果表明:1.微丝对维持细胞表面的完整性有重要作用,CB能破坏微丝故有利于离心去核。2.中等纤维与核之间存在密切联系,这种联系在核膜的某些区域比较集中、牢固,不易为离心力所破坏。3.微管对核固着作用有重要意义,细胞核可能通过中等纤维与微管相连而抛锚在胞质中,故秋水仙素可增强去核作用。微管对维持细胞表面强度可能也有一定作用。     

核体及其贴壁过程的超微结构研究

用细胞松弛素与秋水仙素联合处理IBRS-2细胞,并配合以冲刷法可以制备保存不同胞质量的核体。核体因有质膜与薄层胞质包被,其核内结构保存完好、核仁与染色质结构与正常细胞相似,而裸核因无质膜包被,其核内发生明显的退行性变化。核体在静止培养时,仍具有贴壁铺张能力。核体表面能形成特化结构,如丝足、片层足与微绒毛等,说明在核体所保留的胞质内,细胞骨架仍能发挥功能。     

迟缓爱德华氏菌对Hep-2细胞的侵袭特性

用细胞裂解计数法及超薄切片电镜观察法分析了迟缓爱德华氏菌侵袭ＨＥｐ－２细胞的基本特性。在１５株来源各异的迟缓爱德华氏菌中,有６株细菌具有对ＨＥｐ－２细胞的侵袭能力。细菌侵入细胞后,主要位于空泡内。侵入细胞内的迟缓爱德华氏菌不仅可在细胞内增殖,而且可从细胞内释放出来。用细胞松弛素破坏微丝后可抑制其侵袭作用,而且表现出剂量依赖关系,而在秋水仙素破坏微管后不影响其侵袭力。这表明在迟缓爱德华氏菌对ＨＥｐ－     

迟缓爱德华氏菌对Hep-2细胞的侵袭特性

用细胞裂解计数法及超薄切片电镜观察法分析了迟缓爱德华氏菌侵袭Hep—2细胞的基本特性。在15株来源各异的迟缓爱德华氏菌中,有6株细菌具有对Hep—2细胞的侵袭能力。细菌侵入细胞后,主要位于空泡内。侵入细胞内的迟缓爱德华氏菌不仅可在细胞内增殖,而且可从细胞内释放出来。用细胞松弛素破坏微丝后可抑制其侵袭作用,而且表现出剂量依赖关系,而用秋水仙素破坏微管后不影响其侵袭力。这表明在迟缓爱德华氏菌对Hep—2细胞的侵袭过程中,细胞骨架中有微丝的参与,未发现微管的参与。     

蚕豆叶肉原生质体电融合的研究

本文研究了蚕豆叶肉原生质体经透明质酸酶、核糖核酸酶、神经氨酸酶、碱性磷酸酶、胰蛋白酶、脂肪酶六种水解酶和SDS、Triton X-100、CTMAB三种表面活性剂以及秋水仙素、细胞松驰素B处理后的电融合过程。结果表明:胰蛋白酶处理后的原生质体融合率明显下降;碱性磷酸酶、脂肪酶以及核糖核酸酶、透明质酸酶、神经氨酸酶处理的原生质体电融合率均有不同程度的上升。Triton X-100和CTMAB促进原生质体的电融合,但较高浓度(0.01%)的SDS起抑制作用。秋水仙素和细胞松驰素B处理的原生质体其电融合率有较大幅度的增高。     

Cellular Networks in Epidermal Peels of Onion

Cellular networks ill epidermal peels of onion bulb can be distinguished by first removal of superficially attached cytoplasmic constituents with Triton phos- phate buffer and then by staining with Coomassie blue R 250(Fig. 4). Two distinct kinds of networks can be further recognized by treatment with colchicine and cytochalasins: one thinner network underneath the periphery of plasmalemma can be abolished by colchicine (Fig. 7, 8); and the other thicker one which associates tangentially with the nucleus was more distinctive after cytochalasin B treatment (Fig. 5, 6). Discussion is made regarding these two networks in wall-enclosed plant cells as revealed by the present technic.     

The Effect of Colchicine on Regenerating Membranellar Cilia in Stentor coeruleus

SYNOPSIS. Stentors treated with toxic substances can be induced to shed their oral bands (19, Fig. 1), complex structures composed of many cilia organized into membranelles. Regenerating membranellar bands were observed in control stentors removed from toxic (urea-containing) medium at about 3.5 hours. At 8 hours regenerated control organisms were indistinguishable from normal unshed stentors. Experimental animals replaced into colchicine medium were inhibited from regeneration at low, nontoxic concentrations of this mitotic spindle inhibitor. Upon removal of the colchicine and replacement of the shed animals into normal medium or normal medium to which GTP had been added, complete and normal regeneration of the membranellar band ensued. Our observations are consistent with many suggesting that colchicine acts by reversibly binding with a protein during processes involving microtubule formation. Colchicine inhibition of membranellar band formation further indicates that oral membranelles are specialized evolutionary homologs to other centriole (= basal body, = kinetosome) derivatives such as mitotic spindle fibers, cilia and flagella, axopods, etc. (structures containing the ubiquitous microtubules of eukaryotic cells).     

Doubled haploid plants following colchicine treatment of microspore-derived embryos of oilseed rape (<Emphasis Type="Italic">Brassica napus L.</Emphasis>)

An efficient method for producing doubled haploid plants of oilseed rape (Brassica napus L.) was established using in vitro colchicine treatment of haploid embryos. Haploid embryos in the cotyledonary stage were treated with one of four colchicine concentrations (125, 250, 500 and 1,000 mg/L); for one of three treatment durations (12, 24 and 36 h) at one of the two temperatures (8 and 25°C) and were compared to control embryos (without colchicine treatment). The number of chromosomes, seed recovery, size and density of leaf stomata, and pollen grain size from regenerated plants were determined. No doubled haploid plants were regenerated from control embryos; however, the doubled haploid plants were regenerated from colchicine-treated embryos. A high doubling efficiency, 64.29 and 66.66% of regenerated plants, was obtained from 250 mg/L colchicine treatment for 24 h and 500 mg/L colchicine treatment for 36 h, respectively, at 8°C. Following 500 mg/L colchicine treatment for 36 h, a few plants regenerated (9 plants). At the higher colchicine concentration (1,000 mg/L), no plant regenerated. These results indicate that the colchicine treatment of embryos derived from microspores can induce efficient chromosome doubling for the production of doubled haploid lines of oilseed rape.     

接种叶锈菌的小麦叶片胞间洗脱液对叶肉细胞原生质体微丝骨架的影响

用异硫氰酸 鬼笔环肽 (FITC Ph)标记和共聚焦激光扫描显微镜 (CLSM )观察发现 ,以具有激发子活性的接种叶锈菌的小麦叶片的胞间洗脱液 (IWF)处理叶肉细胞原生质体一定时间后 ,抗病小麦品种洛夫林 10的原生质体内微丝骨架保持完整的网络状结构 ,而感病品种 5 389的大部分微丝骨架处于解聚状态。同时 ,抗病品种因IWF处理诱发的防卫反应———H2 O2 突发和HR反应的程度 (用原生质体活力下降的程度表示 )也大大高于感病品种。用细胞松弛素D(CD)预处理抗病品种原生质体可以明显抑制IWF处理诱发的H2 O2突发和HR反应 ,表明微丝骨架的状态可能与抗病性有密切的关系 ,完整的微丝骨架是H2 O2 突发和HR反应的一个重要条件。     

Effect of cell cycle synchronization on the accuracy of murine and bovine embryo sex determination

Different cell cycle synchronization methods were used to increase the mitotic index and accuracy of sex determination in murine and bovine embryos. For sexing purposes, colchicine treatment for 2, 4, 6 and 8 h and the FdU-thymidine-colchicine combination were tested in murine embryos. The best results were obtained with colchicine treatment for 8 h (96.88% accuracy) and with FdU-thymidine-colchicine (97.22% accuracy). Mitotic indexes differed significantly between the 2 treatments (21.71% for colchicine and 32.95% for FdU-thymidine-colchicine). For sex identification of murine and bovine demi-embryos, both treatments were demonstrated to be equally effective (nearly 90%). The mitotic index for the FdU-treated murine demi-embryos (19.04%) was higher than the one obtained for the 8-h colchicine treatment (15.62%).     

24-表油菜素内酯对低氧胁迫下黄瓜根系抗氧化系统及无氧呼吸酶活性的影响

用营养液水培,研究了根际低氧胁迫下24-表油菜素内酯(EBR)对2个抗低氧能力不同的黄瓜品种根系中抗氧化系统及无氧呼吸酶活性的影响。结果表明,在低氧胁迫下,EBR处理显著提高了低氧胁迫下2品种黄瓜幼苗根系SOD、POD及ADH活性,降低了O2-·、H2O2和MDA含量、LDH活性及‘中农八号’根系PDC活性,而对‘绿霸春四号’根系PDC及2个品种CAT活性无明显影响,表明外源EBR处理通过促进低氧胁迫下根系中抗氧化酶和ADH活性的提高,降低LDH活性及ROS含量,增强植株抗低氧胁迫的能力。     

Destruction and reorganization of the receptor membrane in labellar chemosensory cells of the blowfly. Recovery of responses to sugar after destruction

Recovery from destruction by sodium deoxycholate (DOC) was studied with the receptor membrane of the blowfly, Phormia regina. The recovery can be divided into two processes, colchicine dependent and colchicine independent. The colchicine-dependent process was completely depressed by pretreatment with colchicine at 5 mM for 2 min (partially at 0.1 mM for 10 min), but the colchicine-independent one persisted. Vinblastine also caused depression but lumicolchicine did not. Records of responses obtained from the DOC-treated sugar receptor showed long response latencies that gradually became indistinct with recovery. Colchicine also affected this change in response latency after the DOC treatment. These results suggest that the colchicine-dependent recovery process is related to microtubules in the distal process of the receptor cell. The recovery time course and the change in response latency could be quantitatively explained by the simple assumptions that DOC underwent desorption from the receptor membrane (colchicine-independent recovery process) and that regeneration of the disrupted distal process of the receptor cell accompanied recovery in the number of available receptor sites (colchicine-dependent recovery process).     

Immunofluorescence demonstration of tubulin and actin in estrogen-induced rat prolactinoma cells in vitro : Alteration of their distribution after bromocriptine, colchicine and cytochalasin B treatments

Cultured cells in vitro from estrogen-induced rat prolactin-secreting adenomas (prolactinomas) were examined by indirect immunofluorescence microscopy for the distribution of cytoskeletal proteins and alterations of cytoskeleton after treatment with bromocriptine, colchicine and cytochalasin B (CB). After 8 days in culture, prolactinoma cells were well expanded and developed cytoplasmic processes were seen. The cytoplasmic microtubules were observed as fine reticular networks radiating from perinuclear portions toward the cell periphery when decorated with an antibody against tubulin. On the other hand, the actin filaments showed diffuse and spotty distribution when detected with an anti-actin antibody. Contaminated fibroblasts showed a reticular distribution of microtubules and a parallel array of actin cables which corresponds to "stress fibers" throughout the cytoplasm. After treatment with bromocriptine, the reticular distribution of microtubules in prolactinoma cells changed into a coarse and sparse pattern, which was identical with the changes in the distribution of tubulin after treatment with colchicine. On the other hand, distribution of actin was not affected by bromocriptine. Bromocriptine treatment did not alter the distribution of microtubules and actin filaments in fibroblasts, whereas colchicine changed the distribution of microtubules in both prolactinoma cells and fibroblasts. CB treatment changed the localization of actin filaments in both kinds of cells. These in vitro studies indicated bromocriptine would selectively affect the cytoplasmic microtubular system of prolactinoma cells.     

Antioxidant properties of colchicine in acute carbon tetrachloride induced rat liver injury and its role in the resolution of established cirrhosis

Antioxidant and antifibrotic properties of colchicine were investigated in the carbon tetrachloride (CCl(4)) rat model. (1) The protective effect of colchicine pretreatment on CCl(4) induced oxidant stress was examined in rats subsequently receiving a single lethal dose of CCl(4). Urinary 8-isoprostane, kidney and liver malondialdehyde and kidney glutathione levels increased following CCl(4) treatment, but only the rise in kidney malondialdehyde was significantly inhibited by colchicine pretreatment. Serum total antioxidant levels were significantly higher in the colchicine pretreatment group. (2) The long term effects of colchicine treatment on CCl(4) induced liver damage were investigated using liver histology and biochemical markers (hydroxyproline and type III procollagen peptide). Co-administration of colchicine with sub-lethal doses of CCl(4) over 10 weeks did not prevent progression to cirrhosis. However, rats made cirrhotic with repeated CCl(4) challenge and subsequently treated with colchicine for 12 months, all showed histological regression of cirrhosis. (3) The antioxidant effect of colchicine in vitro was evident only at very high concentrations compared to other plasma antioxidants. In summary, colchicine has only weak antioxidant properties, but does afford some protection against oxidative stress; more importantly, long term treatment with this drug may be of value in producing regression of established cirrhosis.     

Electron microscope investigation of the evolutionary stages of the trophozoite of Didymophyes gigantea (Sporozoa, Gregarinida). III. The fine structure of the epicyte with emphasis on the contractile elements (author's transl)

The fine structure of the epicyte of D. gigantea was investigated. The motility of the gregarine and the contractile elements are described. Four essential types of movements can be observed in this gregarine: (1) rolling up and pendular movements, (2) locomotion by gliding forward, (3) cytoplasmic streaming (Fig. 1), (4) peristaltic contractions (Fig. 2) which seem to be accompanied by the contraction of annular myonemes (Fig. 2). The epicyte is formed by the folding of the parasitic cell wall which is made from three membranes (Figs. 3 and 4). At the top of each fold one can see apical struts between the outer and middle membrane and apical filaments under the inner membrane (Fig. 3). In addition, the epicytic folds are covered by a cell coat which is made from tubular structures (Fig. 5). At the base of the epicytic folds can be observed the basal lamina (Fig. 3) composed of very fine fibrillar material with an average thickness of 2.5 nm (Fig. 6). These fibrils are oriented in the longitudinal axis of the gregarine. Beneath the epicytic fold in the ectoplasm are found the annular myonemes with a width of up to 0.5 micrometers (Fig. 7). They are composed of many fine fibrils with an average thickness of 5 nm. In young trophozoites, the myonemes also contain microtubuli (Fig. 8). Between the epicytic folds, the cell wall is interrupted by three different types of vesicles: the vesicles with an electrondense content (Fig. 9), the three-membranous vesicles (Fig. 10), and the hose-shaped vesicles (Fig. 11). Glycerol-extraction of the parasites was performed in order to define the contractile structures. After extraction the annular myonemes are difficult to recognize (Fig. 13). When ATP is added, the gregarine does not contract but the myonemes reappear after 3 to 4 min (Fig. 14). Differences can also be observed in the myoneme structure using electron microscopy: After extraction, the myonemes are composed of a very limp fibrillar network (Fig. 15) which becomes very dense after the action of ATP (Fig. 16). Glycerol extraction does not disturb either the apical struts and apical filaments or the fibrils of the basal lamina (Figs. 15--17). In addition, cytoplasmic fibrillar structures appear after glycerol extraction (Figs. 15 and 16). The experimental and electron microscope results indicate that the motility of the gregarine depends upon four different systems: (1) the ectoplasmic annular myonemes, (2) the apical structures in the undulating epicytic folds, (3) the cytoplasmic fibrils, and (4) the basal lamina.