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991.
背景:细胞生存的微环境与蛋白的表达密切相关,在不同的环境中癌干细胞标志的表达可能存在差异。
目的:探讨癌干细胞标志CD44、ESA、CXCR4的表达是否会在不同的细胞生存环境中发生改变。
方法:选取舌癌TCA8113细胞系,分别建立干细胞培养基、常规标准培养基以及在标准培养基中添加阿霉素的3种体外培养微环境,采用免疫组化及流式细胞术,检测不同培养环境中3种标志在舌癌细胞中的表达。
结果与结论:免疫组化法检测显示,在所有培养环境中CD44、ESA强阳性表达,CXCR4在干细胞培养基环境中弱阳性表达,其余为阳性表达;流式细胞术检测CD44与ESA在所有培养环境中均高水平表达;与常规标准培养基环境比较,在干细胞培养基的微环境中CXCR4极低水平表达,将舌癌细胞从干细胞培养基转回常规标准培养基后,CXCR4的表达回升;在阿霉素干预的培养环境中,CXCR4表达水平升高。结果表明舌癌干细胞标志在不同体外微环境下的表达存在差异,需结合体内环境与肿瘤组织的表达情况来寻找癌干细胞标志。并且不同微环境模式可能富集不同性质的癌干细胞。 相似文献
992.
背景:以往研究认为,经过成骨诱导后的脂肪基质细胞通过转化为成骨细胞分泌骨基质进而修复骨缺损,然而并没有明确结论证实。
目的:将经过体外成骨诱导的脂肪基质细胞复合支架材料分别植入骨缺损区和非骨区,根据是否成骨,验证经过成骨诱导后的脂肪基质细胞是否转化为成骨细胞。
方法:取12月龄犬背部皮下脂肪,经胶原酶消化法获得单个核细胞,将培养的第3代细胞与双相磷酸钙陶瓷形成复合物。在犬下颌骨两侧制备长20 mm、高10 mm的箱状缺损,拔除术区牙齿,将细胞支架复合物植入一侧术区,空白侧留作对照;另外在犬背部皮下肌肉区植入细胞支架复合物及骨诱导性磷酸钙陶瓷材料,术后6周及12周经组织学检测骨缺损修复情况。
结果与结论:脂肪基质细胞复合双相磷酸钙陶瓷在骨缺损区成骨,在肌肉区未形成新骨;骨诱导性磷酸钙陶瓷在肌肉区形成新骨。提示成骨诱导并不能将脂肪基质细胞转化为成骨细胞,其确切机制有待进一步研究。 相似文献
993.
背景:目前关于镍铬合金烤瓷修复体是否会对人体造成系统性影响的研究尚较少报道。
目的:通过对镍铬合金烤瓷修复体拆除前后患者血清中镍铬元素含量的测定,对其临床应用安全性进行科学评估。
方法:选取因怀疑镍铬烤瓷修复体的镍、铬元素对全身有影响,而要求拆除原修复体的患者69例,在修复体拆除前、拆后1个月,分别运用石墨炉原子吸收光谱法对患者血清中镍、铬含量进行检测,并按年龄、性别、修复体数目、修复体戴入时间以及修复体有无金属暴露等因素进行分组分析。
结果与结论:69例患者在镍铬烤瓷修复体拆除前后所测的血清镍、铬含量结果差异无显著性意义(P > 0.05),而且患者的血清镍、铬含量与年龄、性别、修复体的数量、修复时间以及有无金属暴露等均无明显的相关性(P > 0.05)。提示镍铬合金烤瓷修复体所释放的镍、铬离子量微小,不足以对人体血清中的镍、铬含量造成影响。 相似文献
994.
背景:介孔二氧化硅纳米颗粒具有很多优异的物理性质,在生物医学领域应用广泛,但目前对其生物相容性研究不足。
目的:综述国内外对介孔二氧化硅纳米颗粒生物相容性的研究进展。
方法:检索PubMed、EMBASE、万方、CNKI、维普、中国生物医学数据库有关介孔二氧化硅纳米颗粒细胞毒性和动物毒性的相关文献。
结果与结论:介孔二氧化硅纳米颗粒可通过内吞作用被细胞摄取,其可能通过在细胞内产生活性氧化物导致细胞毒性;介孔二氧化硅纳米颗粒致细胞毒作用与介孔二氧化硅纳米颗粒浓度、颗粒尺寸、表面活性剂去除方式、细胞种类有关。介孔二氧化硅纳米颗粒在动物体内主要富集在肝脏和脾脏,尿液和粪便是其主要排泄途径;介孔二氧化硅纳米颗粒在体内局部生物相容性良好,而大剂量介孔二氧化硅纳米颗粒经腹腔注射或静脉注射可导致严重全身反应。介孔二氧化硅纳米颗粒在体外和体内均显示出较好的生物相容性,但其安全性仍需进一步研究。 相似文献
995.
Complete genome sequence of narcissus late season yellows virus infecting Chinese narcissus in China
The complete genome sequence of a Chinese narcissus isolate of narcissus late season yellows virus from Zhangzhou, China (NLSYV-ZZ), was determined to be 9,651 nucleotides in length, excluding the 3'-terminal poly (A) tail, by amplification and sequencing of virus RNA. The viral genome contains a single long open reading frame of 9,315 nucleotides encoding a polyprotein of 3,105 amino acids. The polyprotein was predicted to be cleaved into ten mature proteins by three viral proteases. Complete genome sequence comparison and phylogenetic analysis indicated that NLSYV-ZZ was most closely related to narcissus yellow stripe virus (NYSV), which was also isolated from narcissus. These viruses shared 69.9 % identity in their complete nucleotide sequences and 77.0 % identity in their polyprotein amino acid sequences. 相似文献
996.
Youyun Zhao Xuan Cao Yi Zheng Jingfeng Tang Wangxi Cai Hanmin Wang Yinglin Gao Yefu Wang 《Journal of medical virology》2012,84(12):1920-1927
Persistent infection with high‐risk HPV, particularly Type HPV 16 and 18, is necessary in the development of cervical cancer, but apart from HPV infection, other causative factors of most cervical cancers remain unknown. The aim of this study was to determine the prevalence of HPV 16 and HPV 18 and HSV 1 and HSV 2 in cervical samples, and to assess the role of HSVs in cervical carcinogenesis. Two hundred thirty‐three healthy controls and 567 cases (333 of cervicitis, 210 of cervical intraepithelial neoplasia, and 24 of squamous cell carcinoma) in cervical exfoliative cells were tested for HPV 16, HPV 18, HSV 1, and HSV 2 DNA using the triplex real‐time polymerase chain reaction method. In contrast to healthy women, positive rate of HPV is related significantly to cervical lesions (odds ratios (ORs) = 4.1, P < 0.01 for cervical intraepithelial neoplasia; ORs = 24.9, P < 0.01 for squamous cell carcinoma), but not cervicitis (ORs = 2.3, P > 0.05). HSV 2 prevalence in cervical intraepithelial neoplasia and squamous cell carcinoma was higher than in healthy women (ORs = 4.9, P < 0.05 for cervical intraepithelial neoplasia; ORs = 4.7, P < 0.05 for squamous cell carcinoma). HSV 2 coinfection with HPV in cervical intraepithelial neoplasia and squamous cell carcinoma was strongly higher than in healthy women (ORs = 34.2, P < 0.01 for cervical intraepithelial neoplasia; ORs = 61.1, P < 0.01 for squamous cell carcinoma). The obtained results indicated that the presence of HPV is associated closely with cervical cancer, and that HSV 2 infection or co‐infection with HPV might be involved in cervical cancer development, while HSV 1 might not be involved. J. Med. Virol. 84:1920–1927, 2012. © 2012 Wiley Periodicals, Inc. 相似文献
997.
背景:细胞在支架上的生长行为受到支架孔径及孔隙率等多种因素影响。
目的:观察在体外中空钛合金假体壁上孔洞直径对骨髓基质干细胞生长及分化的影响。
方法:将中空多孔金属试件按照壁上及底面孔径大小分为:φ1:1 mm;φ2:1.5 mm两组,均置于骨髓基质干细胞悬液中进行成骨诱导培养,以未成骨诱导培养作对照。分别于2,4周倒置相差显微镜观察细胞形态、生长情况,成骨诱导钙结节结果。
结果与结论:4周时φ1实验组孔洞中细胞相向生长并相连,φ2组孔洞中未见相连现象;成骨诱导组在第4周有明显的钙结节形成。表明在体外骨髓基质干细胞在适当的钛合金金属孔径内可直接相向生长并联结,以预防植入物-宿主骨潜在间隙的形成;同时这种空间构型可为再生骨提供足够的生长空间。 相似文献
998.
Li Zhihai Gao Qixue Tao Baohong Lv Jingyao Cai Zhiyi 《Anatomical record (Hoboken, N.J. : 2007)》2008,291(12):1662-1672
Decompression operation of the optic canal via the nasal path under endoscope is widely used, but it is both a challenging and controversial method. Unsatisfactory results were largely associated with otolaryngologists' limited understanding of the real anatomical situations of the optic canal before operation. To provide otolaryngologists with the real situations and data preoperation, multislice helical CT was used to reconstruct the images of the optic canal. Using multislice helical CT‐aided three‐dimensional reconstructive methods in combination with direct anatomic measurement, we dissected and analyzed the shape of the optic canal and its anatomic relationship with the adjoining structures in 40 intact postmortem skull samples. The In‐Space technique clearly showed the structure and the related region of the optic canal. The virtual endoscopy technique showed superbly the spatial appearance and topography of the inner optic canal and also gave the inner structure of the optic canal optically. There was no statistic difference in three‐dimensional reconstructive data with that obtained by anatomical measurements and thus can be used to directly instruct the clinic operation. These results demonstrate that a combined In‐Space technique with virtual endoscopy can accurately define the subtle structure and the related region of the optical canal. In conclusion, multislice helical CT‐based three‐dimensional reconstruction is of important value for clinical operations. Anat Rec, 2008. © 2008 Wiley‐Liss, Inc. 相似文献
999.
V. James Guillory Jinwen Cai Gerald L. Hoff 《Journal of the National Medical Association》2008,100(12):1450-1456
Perinatal periods of risk (PPOR) provide an alternative analytical approach to studying infant mortality. Results can be used to focus community activities to improve infant and maternal health. This article demonstrates the use of PPOR to monitor trends in excess fetal and infant mortality related to disparities associated with race and ethnicity in Kansas City, MO (KC).Based on a comparison of PPOR analyses for 1996-2000 and 2001-2005, there was a 30% reduction in excess fetal and infant mortality in Kansas City and reductions for both non-Hispanic blacks (17%) and non-Hispanic whites (66.7%). However, the disparity ratio for excess mortality rates between non-Hispanic blacks and non-Hispanic whites nearly doubled.Prematurity, the most frequent cause of infant mortality in Kansas City during 2001-2005 accounted for 42.5% of the infant deaths. Being a teenage mother; having less than a high-school education; being unmarried; having an unintended pregnancy; being obese preconceptually; being diabetic; using substances such as tobacco or drugs during pregnancy; receiving late, inadequate or intermediate amounts of prenatal care; having a multifetal pregnancy; having a primary elective cesarean section; delivering a preterm infant or having a male infant; and being enrolled in Medicaid all increased the risk of infant death. 相似文献
1000.
Toll/interleukin-1 receptor (TIR) domain-containing proteins play important roles in defense against pathogens in both animals and plants, connecting the immunity signaling pathways via a chain of specific protein-protein interactions. Among them is SARM, the only TIR domain-containing adaptor that can negatively regulate TLR signaling. By extensive phylogenetic analysis, we show here that SARM is closely related to bacterial proteins with TIR domains, suggesting that this family has a different evolutionary history from other animal TIR-containing adaptors, possibly emerging via a lateral gene transfer from bacteria to animals. We also show evidence of several similar, independent transfer events, none of which, however, survived in vertebrates. An evolutionary relationship between the animal SARM adaptor and bacterial proteins with TIR domains illustrates the possible role that bacterial TIR-containing proteins play in regulating eukaryotic immune responses and how this mechanism was possibly adapted by the eukaryotes themselves. 相似文献