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991.
目的 研究药物1,25-二羟基维生素D3(二羟维D3)在高危角膜移植模型中对免疫排斥反应及新生血管生长情况的影响,揭示1,25-二羟维D3作为免疫抑制剂在角膜移植中的治疗作用及机制。方法 建立大鼠高危角膜移植模型,按不同浓度的1,25-二羟维D3(1×10-5和1×10-7mol/L)及环孢霉素A(CsA)分组,连续用药2周,观察移植物排斥情况并于术后4、7、14d取材行原位杂交等实验,分析各组细胞因子白介素1α(IL-1α)、肿瘤坏死因子-α(TNF-α)、血管内皮生长因子(VEGF)mRNA水平的变化情况。结果 在1,25-二羟维D3作用下,高危角膜移植物的存活时间明显延长;新生血管生长受抑制;合用CsA后效果更明显。原位杂交实验证实1,25-二羟维D3能显著抑制植片IL-1α、TNF-αmRNA表达(P<0.01);对VEGF表达无直接影响。结论 1,25-二羟维D3能有效地抑制新生血管生长及角膜移植急排期的免疫排斥反应,机制可能包括对前炎症因子(IL-1α、TNF-α)生成的抑制作用,而对VEGF无明显直接作用。 相似文献
992.
H. Lang B. A. Schulte R. A. Schmiedt 《Journal of the Association for Research in Otolaryngology》2005,6(1):63-74
Application of ouabain to the intact round-window (RW) membrane of the gerbil cochlea induces apoptosis in most spiral ganglion neurons (SGNs), leaving a few neurons intact (Schmiedt et al. 2002). Here, physiological measures and immunostaining were used to examine the process of SGN degeneration at 3, 6, 12, and 24 h, 4 days, and 1 and 5 months after ouabain treatment. The few remaining neurons surviving up to 5 months after ouabain treatment were immunoreactive for peripherin, a type II neuron marker. Peripherin-positive cell counts indicate that about 7% of the SGNs in the gerbil cochlea are type II neurons, and these neurons survive intact after ouabain treatment. Ouabain exposure had little effect on the outer hair cell and lateral wall systems, even after a 5 month loss of auditory-nerve function. The cellular locations of cytochrome c, poly (ADP-ribose) polymerase (PARP), and activated caspase 3 were examined in control and ouabain-treated cochleas. A redistribution of cytochrome c in peripherin-negative (type I) neurons was observed at 3 h after ouabain exposure. Degraded PARP and activated caspase 3 were also detected in peripherin-negative SGNs at 6 and 24 h after treatment, respectively. These results suggest that the redistribution of cytochrome c is an early event during apoptosis in type I SGNs and that activation of PARP and caspase 3 are associated with apoptosis in these cells. Calcineurin and NF-B are two important signaling pathways that may modulate cell survival in the central nervous system. Here, we found that calcineurin and NF-B selectively labeled type II neurons. It is speculated that the high levels of calcineurin and NF-B in type II SGNs, as compared with type I SGNs, may play protective roles in enhancing the survival of type II neurons exposed to ouabain. 相似文献
993.
农杆菌介导的抗菌肽基因转化阳春砂愈伤组织的研究 总被引:2,自引:0,他引:2
目的确定遗传转化条件,将抗菌肽CN基因转入阳春砂愈伤组织。方法以阳春砂愈伤组织为受体材料,以农杆菌EHA105/pCAMBIA1305.2-CN工程细胞介导抗菌肽CN基因转化阳春砂,设计正交实验,通过分析gus报告基因的瞬时表达比较转化影响因素,并对目的基因CN进行PCR检测。结果农杆菌浓度、侵染时间、共培养温度、共培养时间及乙酰丁香酮浓度对转化率的影响有显著差异性。阳春砂愈伤组织遗传转化的最佳条件组合是:农杆菌浓度为OD600=0.5,侵染时间10 min,共培养温度24℃,共培养时间4 d,共培养培养基添加乙酰丁香酮200μmol.L-1。gus基因瞬时表达呈阳性的愈伤组织DNA经目的基因CN的PCR检测可见清晰的目的条带。结论建立了农杆菌介导的阳春砂愈伤组织的转化条件,目的基因CN已转入阳春砂愈伤组织。 相似文献
994.
Interaction of two members of the heterogeneous nuclear ribonucleoprotein (hnRNP) family with the 3'untranslated region (UTR) of the murine inducible nitric-oxide synthase (iNOS) mRNA is demonstrated in this study. An iNOS RNA-protein complex is formed using protein extracts from untreated and septic shock treated mouse liver. UV cross-linking reveals that the complex consists of at least two proteins, with apparent molecular masses of 60 and 70 kDa, respectively. The 60-kDa protein binding site lies within a 112-nt pyrimidine-rich sequence, approximately 160 nt from the coding sequence, and the RNA-protein complex can be precipitated by a monoclonal antibody directed against hnRNP I [also named polypyrimidine tract binding protein (PTB)]. The 70-kDa protein binds a 43-nt sequence near the 3'end of the 3'UTR and is immunoprecipitated by a monoclonal antibody against hnRNP L. A computer-simulated conformation of the 3'UTR suggests that both binding sites reside in regions easily accessible for a protein. Supershifts of the native RNA-protein complex could only be achieved with anti-hnRNP L, suggesting that within this multiprotein RNA complex, only hnRNP L is exposed to the antibodies, whereas the hnRNP I/PTB is mainly responsible for its interaction with the mRNA. Up-regulation of iNOS by septic shock reduces the RNA-protein complex formation, thus showing that hnRNP I/PTB and hnRNP L binding to the iNOS mRNA is modulated by inflammation. This suggests a novel function for the two previously described proteins as regulators of the iNOS gene. 相似文献
995.
目的探讨去骨瓣减压术引起继发性脑损害的原因和解决方法。方法对本院1998—2006年收治的267例颅内血肿行额颞部去骨瓣减压患者,根据骨窗大小将所有患者分为3组,Ⅰ组5 cm×7 cm~6 cm×11 cm(n=72),Ⅱ组7 cm×12 cm~11 cm×14 cm(n=103),Ⅲ组12 cm×15 cm以上(n=92),记录术前、术后早期血肿对侧上肢运动或语言功能与术后的比较。结果发生继发性脑损害54例。中等大小骨窗的病例继发性损害的发生率为35.9%(37/103),较小或较大的骨窗继发性损害的发生率较低,分别为10.3%(7/72)和10.9%(10/92),修补硬膜者无继发性损害。结论继发于去骨瓣减压的脑损害应引起注意,中等大小骨窗的病例较易发生,保护静脉,保护功能区上方的骨瓣和减张修补硬膜是预防继发性脑损害发生的好方法。 相似文献
996.
OBJECTIVE: Microscopic venous invasion (MVI) is characterized by local destruction of the endothelium by a tumor. The prognostic value of MVI in renal cell carcinoma (RCC) is not well established. MATERIALS AND METHODS: From 1980 until 1990, 255 patients (169 men and 86 women), aged 16-87 (mean 60) years were treated by radical nephrectomy for N0M0 RCC. There were 9 pT1, 163 pT2, 30 pT3a, 34 pT3b, and 19 pT3ab (TNM 1992). The median follow-up time was 74 months. MVI was determined by a double-blind histological study with immunohistochemical staining. RESULTS: MVI was noted in 74 patients (29%). MVI significantly increased metastatic progression (p = 0.003). Only stage and Fuhrman's grade were significant factors for metastatic progression in a multivariate analysis. MVI decreased the actuarial survival rates at 1 year (p = 0.01), but not significantly at 5 and 10 years. MVI and non-MVI survival curves were statistically different with the Peto/Wilcoxon (p = 0.04) and Gehan/Wilcoxon (p = 0.03) tests, but not with the log rank test (p = 0.06). MVI decreased survival in cases with a tumor size of 10 cm or more, capsular invasion, macroscopic venous invasion, stage pT3ab, sarcomatoid cell carcinoma and Fuhrman's grade IV. Only the stage was a significant factor for survival in a multivariate analysis. CONCLUSION: In RCC, MVI is related to cancer progression and survival, but probably not as an independent prognostic factor. 相似文献
997.
目的 考察壳聚糖包衣脂质体对α糜蛋白酶降解醋酸亮丙瑞林的保护作用。方法 首先通过荧光扫描和荧光淬灭实验考察脂质体对色氨酸基团的包封程度,然后将包封醋酸亮丙瑞林的脂质体与α糜蛋白酶共培养,测定醋酸亮丙瑞林的残留量,同时还考察了壳聚糖对α糜蛋白酶的吸附。结果 脂质体中醋酸亮丙瑞林发射峰强度增加,峰位产生2nm蓝移。碘化钠对游离醋酸亮丙瑞林的淬灭是脂质体包封醋酸亮丙瑞林的2.69倍,丙烯酰胺对游离醋酸亮丙瑞林的淬灭是脂质体包封醋酸亮丙瑞林的2.23倍。壳聚糖对α糜蛋白酶有一定吸附,但是吸附后并不改变酶的活性。与α糜蛋白酶共培养1h,游离药物残留量为0,脂质体中仍残留(38.91±2.39)%药物,而脂质体加入壳聚糖后药物残留量为(46.17±6.29)%。结论 醋酸亮丙瑞林分子中易降解基团色氨酸残留部分已插入脂质双分子层,壳聚糖通过聚合物的空间位阻和黏性对脂质体中药物有进一步保护作用。 相似文献
998.
Cancer stem cells have been isolated from various types of cancer including leukemia and solid tumors. However, the methods for isolating gastric cancer stem-like cells (GCSCs) have not been well established. As a consequence, the biological behavior and the significance of these cells to cancer progression remains to be clarified. In this study, we isolated and characterized GCSCs from a gastric cancer cell line SGC7901 and found their enhanced capabilities of invasion in vitro and metastasis in vivo. We further studied the expression of molecules related to epithelial-mesenchymal and invasion in GCSCs and found there were decreased E-cadherin, but increased vimentin and matrix metalloproteinase 2 (MMP-2), in these cells. Our results suggest that decreased E-cadherin and increased MMP-2 may be associated with the capacity of GCSCs to metastasize. 相似文献
999.
Dr. S. Jakob Z. Gatzioufas U. Löw A. Osvald M. Lang K. Brückner B. Seitz 《Der Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft》2010,107(4):366-369
We present the case of a 77-year-old female patient who complained of dizziness. Consequently, a magnetic resonance imaging (MRI) examination was performed to rule out an intracranial tumor. The examination revealed an intraocular structure with signal hyperintensity in the left eye. The patient was referred to our clinic to screen for an intraocular tumor. Ophthalmological findings together with the medical history unmasked the “tumor” as residual perfluorodecaline vesicles. 相似文献
1000.
A. M. Huber I. Gaboury D. A. Cabral B. Lang A. Ni D. Stephure S. Taback P. Dent J. Ellsworth C. LeBlanc C. Saint‐Cyr R. Scuccimarri J. Hay B. Lentle M. Matzinger N. Shenouda D. Moher F. Rauch L. M. Ward Canadian Steroid‐Associated Osteoporosis in the Pediatric Population Consortium 《Arthritis care & research》2010,62(4):516-526