检索结果-内蒙古大学图书馆

HUMAN PATHOLOGY 1975年第5期6卷 611-621页

作者： HIRANO, A MATSUI, T ALBERT EINSTEIN COLL MED 1300 MORRIS PK AVEBRONXNY 10461 MONTEFIORE HOSP & MED CTR DEPT PATHOLDIV NEUROPATHOLBRONXNY

The blood vessels within brain tumors show alterations from the normal anatomy. Some of these seem to be related to an increased capacity to transfer materials between the lumen and the parenchyma and are probably intimately connected with the edema associated with the tumor. These alterations include fenestration, widened intercellular junctions, increase in pinocytotic vesicles, and infolding of the luminal surface. Other alterations are observed but their function is not as clear. The latter include an increase in the number of tubular bodies, the appearance of tubular structures within vacuoles, tubular arrays within the nuclear envelope and rough endoplasmic reticulum, and endothelial proliferation, among others.

关键词：基膜/超微结构脑肿瘤/血液供给毛细血管/超微结构颅咽管瘤/血液供给无性细胞瘤/血液供给内皮/超微结构神经胶质瘤/血液供给细胞连接/超微结构髓母细胞瘤/血液供给微体/超微结构微管/超微结构类器官/超微结构胞饮作用空泡/超微结构人类

来源：评论

学校读者我要写书评

暂无评论

Microtubule dysfunction by posttranslational nitrotyrosination of α-tubulin:: A nitric oxide-dependent mechanism of cellular injury

引用

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 1999年第11期96卷 6365-6370页

作者： Eiserich, JP Estévez, AG Bamberg, TV Ye, YZ Chumley, PH Beckman, JS Freeman, BA Univ Alabama Dept Anesthesiol Birmingham AL 35233 USA Univ Alabama Ctr Free Rad Biol Birmingham AL 35233 USA Univ Alabama Dept Biochem & Mol Genet Birmingham AL 35233 USA Univ Republ Fac Ciencias Secc Neurociencias Montevideo 11200 Uruguay

NO(2)Tyr (3-Nitrotyrosine) is a modified amino acid that is formed by nitric oxide-derived species and has been implicated in the pathology of diverse human diseases. Nitration of active-site tyrosine residues is known to compromise protein structure and function, Although free NO(2)Tyr is produced in abundant concentrations under pathological conditions, its capacity to alter protein structure and function at the translational or posttranslational level is unknown. Here, we report that free NO(2)Tyr is transported into mammalian cells and selectively incorporated into the extreme carboxyl terminus of cu-tubulin via a posttranslational mechanism catalyzed by the enzyme tubulin-tyrosine ligase, In contrast to the enzymatically regulated carboxyl-terminal tyrosination/detyrosination cycle of alpha-tubulin, incorporation of NO(2)Tyr shows apparent irreversibility, Nitro-tyrosination of alpha-tubulin induces alterations in cell morphology, changes in microtubule organization, loss of epithelial-barrier function, and intracellular redistribution of the motor protein cytoplasmic dynein, These observations imply that posttranslational nitrotyrosination of Lu-tubulin invokes conformational changes, either directly or via allosteric interactions, in the surface exposed carboxyl terminus of cu-tubulin that compromises the function of this critical domain in regulating microtubule organization and binding of motor-and microtubule-associated proteins. Collectively, these observations illustrate a mechanism whereby free NO(2)Tyr can impact deleteriously on cell function under pathological conditions encompassing reactive nitrogen species production. The data also yield further insight into the role that the alpha-tubulin tyrosination/detyrosination cycle plays in microtubule function.

关键词：氨基酸序列结合部位细胞膜通透性动力蛋白/代谢微管/生理学微管/超微结构一氧化氮/代谢肽合酶类/代谢蛋白质加工转译后微管蛋白/化学微管蛋白/代谢肿瘤细胞培养的酪氨酸/类似物和衍生物酪氨酸/代谢人类

来源：评论

学校读者我要写书评

暂无评论

FINE-STRUCTURE OF SPERMATOZOON OF AN ONYCHOPHORAN, PERIPATOPSIS

引用

TISSUE & CELL 1976年第4期8卷 659-672页

作者： BACCETTI, B DALLAI, R BURRINI, AG SELMI, G IST ZOOL I-53100 SIENA ITALY

The spermatozoon of the onychophoran P. moseleyi is described. This cell is characterized by the general filiform shape, the absence of an acrosome, the presence of mitochondrial derivatives, of an annulus, and 9 accessory tubules and a manchette of microtubules around the axoneme. All these characters are typical of highly evolved sperm models, like those of insects and mammals, and suggest a long evolutionary history. Only the position of the mitochondria, inserted between nucleus and axoneme, is reminiscent of annelid features.

关键词：节肢动物/超微结构细胞核/超微结构微管/超微结构线粒体/超微结构精子头/超微结构精子能动性精子尾/超微结构精子/超微结构动物男(雄)性

来源：评论

学校读者我要写书评

暂无评论

Drug-induced changes of cytoskeletal structure and mechanics in fibroblasts: An atomic force microscopy study

引用

BIOPHYSICAL JOURNAL 2000年第1期78卷 520-535页

作者： Rotsch, C Radmacher, M Univ Munich Lehrstuhl Angew Phys D-80799 Munich Germany

The effect of various drugs affecting the integrity of different components of the cytoskeleton on the elasticity of two fibroblast cell lines was investigated by elasticity measurements with an atomic force microscope (AFM). Disaggregation of actin filaments always resulted in a distinct decrease in the cell's average elastic modulus indicating the crucial importance of the actin network for the mechanical stability of living cells. Disruption or chemical stabilization of microtubules did not affect cell elasticity. For the f-actin-disrupting drugs different mechanisms of drug action were observed. Cytochalasins B and D and Latrunculin A disassembled stress fibers. For Cytochalasin D this was accompanied by an aggregation of actin within the cytosol. Jasplakinolide disaggregated actin filaments but did not disassemble stress fibers. Fibrous structures found in AFM images and elasticity maps of fibroblasts could be identified as stress fibers by correlation of AFM data and fluorescence images.

关键词： 3T3细胞肌动蛋白类/代谢抗肿瘤药/药理学二环化合物杂环/药理学细胞系秋水仙碱/药理学细胞松弛素B/药理学细胞松弛素D/药理学细胞骨架/药物作用细胞骨架/超微结构秋水仙胺/药理学缩肽类弹性成纤维细胞/细胞学成纤维细胞/药物作用成纤维细胞/超微结构动力学海生毒素类/药理学显微镜检查原子力/方法显微镜检查荧光/方法微管/药物作用微管/超微结构紫杉酚/药理学肽类环/药理学应力物理噻唑类/药理学噻唑烷类动物小鼠大鼠

来源：评论

学校读者我要写书评

暂无评论

ROLE OF INTERMEDIATES IN MICROTUBULE ASSEMBLY INVIVO AND INVITRO

引用

ANNALS OF THE NEW YORK ACADEMY OF SCIENCES 1975年第JUN30期253卷 78-89页

作者： WEISENBERG, R ROSENFELD, A TEMPLE UNIV DEPT BIOL PHILADELPHIA PA 19122 USA MARINE BIOL LAB WOODS HOLE MA 02543 USA

来源：评论

学校读者我要写书评

暂无评论

UNUSUAL ARRANGEMENT OF AGRANULAR ENDOPLASMIC-RETICULUM IN INTERSTITIAL-CELLS OF CAT OVARY

引用

FERTILITY AND STERILITY 1975年第4期26卷 346-352页

作者： MOTTA, P COLUMBIS, P DIDIO, LJA UNIV ROME DEPT NORMAL HUMAN ANAT ROME ITALY MED COLL OHIO DEPT ANAT TOLEDO OH USA

An unusual arrangement of agranular endoplasmic reticulum in the interstitial cells of the cat ovary is described. The structural unit of this arrangement in cross section consists of five membranous sacs (800 to 900 A long and 250 to 350 A wide) radially coverging toward a microtubule. The sacs are separated from each other by three angles of 60 degrees and two of 90 degrees. In longitudinal section, the sacs appear to be long parallel cisternae. The geometric, radial arrangement seems to arise from a gradual incurvation and convergence of parallel units in these membranes. The microtubules may act as guides for the polarization and resulting unusual arrangement of the membranes. The purpose of such polarization may be related to a change from protein to steriod synthesis in these cells.

关键词：生物统计学细胞学技术内质网/代谢内质网/超微结构显微镜检查电子显微切片术微管/代谢微管/生理学微管/超微结构卵巢/细胞学蛋白质生物合成甾类/生物合成动物猫女(雌)性

来源：评论

学校读者我要写书评

暂无评论

Contribution of active zone subpopulation of vesicles to evoked and spontaneous release

引用

JOURNAL OF NEUROPHYSIOLOGY 1999年第4期81卷 1495-1505页

作者： Koenig, JH Ikeda, K City Hope Natl Med Ctr Beckman Res Inst Div Neurosci Duarte CA 91010 USA

Our previous work on Drosophila synapses has suggested that two vesicle populations possessing different recycling pathways, a fast pathway emanating from the active zone and a slower pathway emanating from sites away from the active zone, exist in the terminal. The difference in recycling time between these two pathways has allowed us to create a synapse that possesses the small, active zone subpopulation without the larger, nonactive zone population. Synapses were depleted using the temperature-sensitive endocytosis mutant, shibire, which reversibly blocks vesicle recycling at the restrictive temperature. In the depleted state, both the excitatory junction potential (EJP) and spontaneous release are abolished. After shibire-induced depletion. the active zone population begins to reform within 30 s at the permissive temperature. whereas the nonactive zone population does not begin to reform until similar to 10-15 min later. Evoked release recovered at approximately the same time as the active zone population. During the time when the active zone population existed in the terminal without the nonactive zone population, enough transmitter release was available to sustain a normal evoked response for many minutes at frequencies above those produced during normal activity (flight) by this motor neuron. When only the active zone population existed in the terminal, the frequency of spontaneous release was greatly attenuated and possessed abnormal release characteristics. Spontaneous release recovered its predepletion frequency and release characteristics only after the nonactive zone population was reformed.

关键词：果蝇蛋白质类黑腹果蝇/遗传学动力蛋白质类 GTP磷酸水解酶类/遗传学显微镜检查电子微管/生理学微管/超微结构突变/生理学神经肌肉接头/生理学神经肌肉接头/超微结构突触传递/遗传学突触小泡/生理学突触小泡/超微结构温度动物女(雌)性

来源：评论

学校读者我要写书评

暂无评论

Microtubule alterations in cultured taiep rat oligodendrocytes lead to deficits in myelin membrane formation

引用

JOURNAL OF NEUROCYTOLOGY 1999年第8期28卷 671-683页

作者： Song, J O'connor, LT Yu, W Baas, PW Duncan, ID Univ Wisconsin Sch Vet Med Dept Med Sci Madison WI 53706 USA Univ Wisconsin Sch Med Dept Anat Madison WI 53706 USA

The taiep rat is a myelin mutant in which hypomyelination and progressive demyelination of the CNS are accompanied by an accumulation of microtubules within oligodendrocytes. To investigate whether and how the myelin defects were caused by microtubule abnormalities, we have established a taiep oligodendrocyte culture system in which mutant cells produce abnormally high levels of tubulin and microtubule-associated proteins and exhibit myelin defects. The studies show that abnormal microtubule accumulation and tight microtubule bundles developed in the taiep oligodendrocytes, with a higher ratio of minus-end-distal to plus-end-distal microtubules in their processes. Initially, in culture, immature taiep oligodendrocytes which have higher levels of tubulin than controls extend roughly twice as much membrane sheet as controls. The membrane sheets of the mature taiep oligodendrocytes which display the microtubule accumulation, however, grew much less rapidly compared to controls. By the fifth day in culture, a majority of the taiep oligodendrocytes had ceased the expansion of their membrane sheets and in some cases the sheets retracted. The levels of the myelin proteins, proteolipid protein and myelin-associated glycoprotein, were also markedly diminished in the mature taiep oligodendrocytes. Treatment with the microtubule depolymerizing drug nocodazole prevented not only the accumulation of microtubules but also restored the normal distribution of proteolipid proteins within the taiep oligodendrocytes. These data demonstrate that myelin synthesis in the oligodendrocyte cultures relies on the formation of a normal microtubule array, and the microtubule abnormalities are directly responsible for the myelin deficit in the taiep oligodendrocytes.

关键词：细胞培养的脱髓鞘疾病/遗传学脱髓鞘疾病/病理学脱髓鞘疾病/病理生理学荧光抗体技术显微镜检查电子微管相关蛋白质类/分析微管/生理学微管/超微结构髓磷脂蛋白脂质蛋白质/分析髓鞘/化学髓鞘/病理学髓鞘/生理学少突神经胶质/生理学少突神经胶质/超微结构大鼠突变系脊髓/细胞学微管蛋白/分析动物大鼠

来源：评论

学校读者我要写书评

暂无评论

ASSEMBLY OF MICROTUBULES ONTO KINETOCHORES OF ISOLATED MITOTIC CHROMOSOMES OF HELA-CELLS

引用

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 1975年第10期72卷 4023-4027页

作者： TELZER, BR MOSES, MJ ROSENBAUM, JL YALE UNIV DEPT BIOLNEW HAVENCT 06520 DUKE UNIV MED CTRDEPT ANATDURHAMNC 27710

The kinetochores of isolated HeLa cell chromosomes attached to an electron microscope specimen grid, fixed in formaldehyde, and stained with alcoholic phosphotungstic acid are visible as dark, preferentially stained structures distinct from the chromatin with which they are associated. When unfixed chromosomes are immobilized by attachment to grids and incubated with chick brain tubulin, microtubules are observed to assemble onto the kinetochores. This demonstrates the competence of kinetochores in isolated chromosomes to act in vitro as microtubule assembly sites and suggests that they also possess this capacity in vivo. In addition, the results provide a possible means for isolating and characterizing kinetochores.

关键词：染色体/超微结构 HeLa细胞/超微结构显微镜检查电子微管/超微结构有丝分裂人类

来源：评论

学校读者我要写书评

暂无评论

Dynamic imaging of the metaphase II spindle and maternal chromosomes in bovine oocytes: Implications for enucleation efficiency verification, avoidance of parthenogenesis, and successful embryogenesis

引用

BIOLOGY OF REPRODUCTION 2000年第1期62卷 150-154页

作者： Dominko, T Chan, A Simerly, C Luetjens, CM Hewitson, L Martinovich, C Schatten, G Oregon Hlth Sci Univ Oregon Reg Primate Res Ctr Beaverton OR 97006 USA Oregon Hlth Sci Univ Dept Obstet & Gynecol Portland OR 97201 USA Oregon Hlth Sci Univ Dept Dev & Cell Biol Portland OR 97201 USA Oregon Hlth Sci Univ Ctr Womens Hlth Portland OR 97201 USA

Manipulations of DNA and cellular structures are essential for the propagation of genetically identical animals by nuclear transfer. However, none of the steps have been optimized yet. This study reports a protocol that improves live dynamic imaging of the unfertilized bovine oocyte's meiotic spindle microtubules with microinjected polymerization-competent X-rhodamine-tubulin and/or with vital long-wavelength excited DNA fluorochrome Sybr14 so that the maternal chromosomes can be verifiably removed to make enucleated eggs the starting point for cloning. Suitability of the new fluorochromes was compared to the conventional UV excitable Hoechst 33342 fluorochrome. Enucleation removed the smallest amount of cytoplasm (4-7%) and was 100% efficient only when performed under continuous fluorescence, i.e., longer fluorescence exposure. This was in part due to the finding that the second metaphase spindle is frequently displaced (60.7 +/- 10%) from its previously assumed location subjacent to the first polar body. Removal of as much as 24 +/- 3% of the oocyte cytoplasm underneath the polar body, in the absence of fluorochromes, often resulted in enucleation failure (36 +/- 6%). When labeled oocytes were exposed to fluorescence and later activated, development to the blastocyst stage was lowest in the group labeled with Hoechst 33342 (3 %), when compared to Sybr14 (19%), rhodamine-tubulin (23%), or unlabeled oocytes (37%). This suggests that longer wavelength fluorochromes can be employed for live visualization of metaphase spindle components, verification of their complete removal during enucleation, and avoidance of the confusion between artifactual parthenogenesis versus "cloning" success, without compromising the oocyte's developmental potential after activation.

关键词：苯咪唑类染色体/超微结构细胞质/超微结构 DNA/分析荧光染料减数分裂中期微管/超微结构核移植技术卵母细胞/超微结构单性生殖紫外线动物牛女(雌)性

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：