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991.
The labeling of retina ganglion cell and optic tectum phospholipids was determined in chickens given an intraocular injection of 32P and then either exposed to light or maintained in the dark. Significantly higher labeling was found in the optic tectum phospholipids of light-exposed compared with dark-maintained animals after 3-24 h of labeling. In the ganglion cells, the labeling of phospholipids increased in dark with respect to light at 15 and 30 min of labeling; from 60 min to 24 h, the labeling of phospholipids was significantly higher in light with respect to dark, even if the precursor pool showed a higher labeling in dark at all times studied. When labeling was allowed to proceed in the dark for 30 min and then half of the animals were exposed to light for 15 min, the labeling of ganglion cell phospholipids of light-exposed animals was significantly higher than those of animals kept in the dark. No individual phospholipid accounted for the differences observed in the labeling of the total phospholipid pool. These results are interpreted as an increase in the biosynthesis of phospholipids in the ganglion cell somas in light with respect to dark.  相似文献   
992.
城市内部居住环境的客观性评价有助于发现城市发展中暴露出的问题,有针对性地进行调整进而改善城市环境。以福州市中心城区为研究区,居住区为研究单元,利用气象监测数据、遥感影像数据、地图兴趣点数据、国土规划数据等多源数据,从环境健康舒适性、交通便捷性、城市安全性和生活方便性4方面构建城市人居环境监测体系,并使用优劣解距离法进行人居环境质量综合评价。结果表明: 福州市中心城区人居环境水平差异性较大,整体上呈现出中心区域高、边缘地区低的特点。城区中部人居环境指数较高,东部和南部区域较低,西部和北部区域人居环境高值与低值混杂分布。各指标层中,交通便捷性和生活方便性的高-高集聚以及低-低集聚特征与人居环境高低值聚类分布较为一致,便捷的交通以及完备的服务设施对人居环境评价的影响较大;环境健康舒适性呈现城市内部低、边缘高的特点,而城市安全性呈现内部高、边缘低的特点。  相似文献   
993.
目的:利用不同浓度的桦木酸对人胃癌SGC-7901细胞增殖的影响。方法:桦木酸设4个不同浓度(0、10、20、30 μg/ml),并采用常规化疗药物5-Fu处理作为阳性对照,以探究其对细胞增殖的影响。采用台盼蓝拒染法和吉姆萨染色法分别检测桦木酸对人胃癌SGC-7901细胞生长抑制率及克隆形成率;EdU法检测SGC-7901的细胞增殖;利用流式细胞术检测细胞周期, 应用qRT-PCR和Western blot分别检测细胞周期蛋白cyclin D1,cyclin B1的mRNA和蛋白表达水平。结果:不同浓度的桦木酸处理人胃癌SGC-7901细胞48 h后,其细胞生长抑制率显著升高(P<0.05),克隆形成率和细胞增殖率均明显降低(P<0.01),且呈剂量和时间依赖性;人胃癌SGC-7901细胞被阻滞在G1/G0期,细胞周期蛋白cyclin D1和cyclin B1的mRNA和蛋白表达量也随桦木酸浓度升高而显著降低(P<0.01)。且与5-Fu对照组相比,桦木酸浓度为20 μg/ml和30 μg/ml时,细胞增殖能力明显降低,细胞周期被抑制,细胞周期蛋白表达量均明显降低(P <0.05)。结论:桦木酸通过下调cyclin B1和cyclin D1基因表达,将人胃癌SGC-7901细胞阻滞在G1/G0期,从而抑制细胞增殖。  相似文献   
994.
Therapeutic ultrasound was administered to patients suffering from bone fracture with FDA approval. Bone and cartilage are piezoelectric materials. To investigate the effects of piezoelectricity on the cells of chondrogenic lineage, we applied ultrasound stimulation on an AT-cut quartz coverslip to generate electric field fluctuations. The bone-marrow-derived mesenchymal stem cells (BMMSC) and primary chondrocytes were cultured on either glass or quartz coverslips for ultrasound stimulation. The cells were immunofluorescent-labeled for the assessment of cell arrangement and ciliary orientation. Ultrasound and piezoelectricity both stimulate cell migration and disrupt ciliary orientation induced by directional migration. In particular, piezoelectric effects on cell rearrangement can be abolished by the inhibitor specifically targeting atypical Protein kinase C zeta (PKCζ). Our findings shed light on the possibility of cellular modulation by using piezoelectric manipulation.  相似文献   
995.
Summary We have developed an improved serum-free medium to optimize the cell growth of bovine granulosa cells. The cells on collagen-coated culture plates proliferated extensively in a nutrient medium supplemented with insulin, heparin binding growth factor-2 (HBGF-2), lipoprotein, and bovine serum albumin (BSA). The cell doubling time at logarithmic phase and final cell density at confluent cultures were equal to those of cultures grown in the presence of medium supplemented with optimal concentration (10%) of fetal bovine serum (FBS). Whereas HBGF-2 or insulin alone had a small mitogenic effect of granulosa cells, lipoprotein or BSA did not. When lipoprotein, BSA, or insulin was added together with HBGF-2, synergistic cell proliferation was observed in all combinations. Insulin or lipoprotein had an additive mitogenic stimulation of these cells in the presence of BSA. After granulosa cells were subcultivated in a serum-containing medium until three generations [8.5 cumulative population doubling level (CPDL)], subsequent subcultivation of the cells in a complete serum-free medium could be achieved up to six generations (14.4 CPDL). These results demonstrate that this serum-free medium can support the optimal cell growth and long-term subcultivation of bovine granulosa cells.  相似文献   
996.
Summary Sperm cells of pollen tubes grown both in vivo and in vitro form a male germ unit. Extensions from both sperm cells of each pollen tube are closely associated with the tube nucleus. A high yield (2.7 × 104. 20 mg–1 pollen grains germinated) of intact sperm cells was obtained following release by osmotic shock from pollen tubes grown in vitro. Structural integrity of isolated sperm was maintained by isolation at low temperature in an osmotically balanced medium. At 4° C many isolated sperm pairs were still enclosed within the pollentube inner plasma membrane. Sperm cells not enclosed within this membrane no longer remained connected as a pair. During isolation vesicles formed on the sperm cell surface from disruption of the fibrillar components bridging the periplasmic space. Both in the pollen tube and after isolation the sperm nucleus is in close association with at least one region of the sperm plasma membrane. Sperm isolated at room temperature showed the presence of nucleopores, and nuclei were euchromatic, instead of heterochromatic as in intact sperm in the pollen tube.  相似文献   
997.
摘要 目的:旨在探究miR-613在胶质瘤中的表达及对细胞增殖、侵袭和血管生成的影响。方法:根据细胞转染将实验分组为对照miRNA组(Control组)、miR-613模拟物组(mimics组)和miR-613 mimics+VEGFA组(VEGFA组)。采用逆转录定量聚合酶链反应(RT-qPCR)检测胶质瘤细胞和组织中miR-613和VEGFA mRNA的表达水平;采用荧光素酶报告基因分析miR-613与血管内皮生长因子(VEGF)的关系;采用Western blotting检测VEGFA蛋白的表达水平;通过体外实验检测转染细胞的增殖能力、侵袭能力和管状形成能力。结果:与正常组织样本相比,胶质瘤I-II期组样本的肿瘤细胞呈现异形,具有深核染色,并且肿瘤细胞密度适度较低,而胶质瘤III-IV期组样本的肿瘤细胞的核分裂活跃,具有明显的微血管增殖和明显的细胞异型性;miR-613在胶质瘤I-IV期组织样本中显著降低(P<0.05)。在U87和U251细胞系的VEGFA-WT组中,与Control组相比,mimics组的荧光素酶活性显著降低(P<0.05)。与Control组相比,U87和U251细胞系中mimics组VEGFA的mRNA和蛋白表达水平均显著降低(P<0.05)。克隆形成实验、血管生成实验和细胞侵袭实验结果表明,与Control组相比,mimics组的克隆形成数量、细胞侵袭数、内皮细胞HUVEC的管状形成数和Ang-2蛋白表达水平均显著降低(P<0.05);与mimics组相比,VEGFA组克隆形成数量、细胞侵袭数、内皮细胞HUVEC的管状形成数和Ang-2蛋白表达水平均显著升高(P<0.05)。结论:miR-613通过靶向VEGFA抑制了神经胶质瘤细胞的侵袭、增殖和血管生成,提示miR-613可能成为未来治疗胶质瘤的潜在靶点。  相似文献   
998.
《Developmental cell》2021,56(16):2381-2398.e6
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999.
软骨血管生成抑制因子抑制血管生成的研究   总被引:13,自引:1,他引:13  
小牛气管软骨经盐酸胍抽提,丙酮分级沉淀,膜超滤,柱层析等步骤得到软骨血管生成抑制因子(cartilage angiogenesis inhibiting factor,CAIF).SDS-聚丙烯酰胺凝胶电泳显示CAIF由单一组分组成,分子量为27700.通过[ 3H]-TdR掺入,活细胞检测等方法测定CAIF对内皮细胞、Hela细胞、QGY7703细胞与小鼠骨髓细胞、人皮肤成纤维细胞等的DNA合成的影响,以及细胞毒作用.采用鸡胚绒毛尿囊膜实验测定CAIF对血管生成的抑制效应.结果显示:CAIF对内皮细胞产生强的抑制作用,对Hela细胞抑制很弱,对QGY7703细胞、小鼠骨髓细胞、人皮肤成纤维细胞均无抑制作用;对鸡胚绒毛尿囊膜的血管生成产生明显的抑制作用.提示CAIF能较特异地抑制血管生成,CAIF达到电泳纯,是专一性较强的血管生成抑制因子.  相似文献   
1000.
Summary The ovarian mesothelium (OM) represents the tissue of origin of ovarian epithelial cancer. To gain insight into the regulation of this tissue, OM organoids and submesothelial ovarian stromal cells (SC) were isolated from New Zealand White rabbits by a stepwise tissue dispersal technique, while granulosa cells (GC) were aspirated from mature follicles (14±4 groups/animal). OM and SC dispersal were sequentially accomplished by: a) 1-h incubation in collagenase type I (300 U/ml), gentle scraping of the ovarian surface, and 1 g sedimentation of OM organoids (equivalent to 0.93±0.40 × 106 cells/animal) on 5% bovine serum albumin (BSA); b) 2-h incubation in pronase-collagenase (0.5%–300 U/ml) under periodical resuspension and gentle scraping of SC (1.40±0.25 × 106/animal) from OM-denuded ovaries. After a week-long in vitro expansion, OM cells (OMC) were cultured alone and with SC or GC within monocameral vessels or bicameral transfilter vessels in serumless, fibronectinrich (4μg/ml) HL-1 medium. After 7 d of contact cell-cell interaction, cytokeratin-positive OMC became surrounded by fibroblastoid, vimentin-positive SC or by cytokeratin and vimentin-weakly positive GC. Filter-bound OMC humorally interacting with underlying SC or GC displayed a biphasic, epithelioid and spindle, morphology with universal cytokeratin expression. Bromo-2′-deoxyuridine (BrdU) immunoperoxidase revealed mean cell proliferation indices of 14.88% for OMC cultured alone, 11.21% and 19.39% for OMC cultured with GC or SC in monocameral dishes, and 15.25% or 22.47% for OMC cultured in bicameral vessels over GC or SC, respectively. This model provides an experimental tool for investigating the unexplored role of stromal-mesothelial interaction in OM pathobiology.  相似文献   
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