烧伤血清刺激对大鼠肠上皮细胞结构和粘弹性的影响

目的　动态观察烧伤血清对体外肠上皮细胞 (IEC)骨架和细胞生物力学 (粘弹性 )的影响。　方法　培养大鼠肠上皮细胞株IEC 6 ,用烧伤血清刺激后 ,通过细胞骨架免疫组化、细胞ELISA法定量分析以及粘弹性测定技术 ,动态观察IEC致伤前后的变化。　结果　IEC在烧伤血清作用早期 ,骨架蛋白的表达即明显降低 ,微丝、微管蛋白阳性信号减弱 ,细胞粘弹性下降。　结论　细胞骨架的损伤可引起细胞脆性增加、粘弹性下降 ,导致细胞生物力学特性的改变。这种变化 ,可能直接参与烧伤后肠上皮细胞损伤的发生。     

人骨髓间充质干细胞体外分化为雪旺样细胞的方法

目的 :建立人骨髓间充质干细胞体外向雪旺样细胞定向诱导分化的方法。方法 :取健康人骨髓血标本 ,利用percoll(密度为 1.0 73 g·ml-1)分离骨髓单个核细胞 ,在DMEM LG + 10 % (体积分数 )FBS中培养 ,通过流式细胞术对培养细胞进行表型测定 ,对第 2、3、5、8代间充质干细胞进行定向诱导分化 ,用单抗S 10 0、神经胶质纤维酸性蛋白 (glialfibrillargacidicprotein ,GFAP) ,通过免疫组化方法对诱导的细胞进行鉴定。 结果 :经 percoll分离的间充质干细胞可传 16代 ,细胞数增加了大约 6× 10 7倍。流式细胞术结果显示 :percoll分离出来的未经培养的细胞 ,其CD2 9+CD4 4 +CD3 4 -CD4 5 -细胞数为 3 2 .4 7%± 3 .4 9% ,而培养后贴壁细胞中CD2 9+CD4 4 +CD3 4 -CD4 5 -细胞数为 94 .3 8%± 1.5 0 %。诱导后免疫组化染色结果显示 :由 β ME +bFGF预诱导、β ME +bFGF诱导的S 10 0阳性细胞最多 ,可达 90 %± 4 % ,GFAP阳性细胞为 2 1%± 5 %。结论 :人骨髓中间充质干细胞能定向诱导分化成雪旺样细胞。     

实验性急性胰腺炎肺内细胞凋亡状况及其意义的初步探讨

目的：探讨重症急性胰腺炎时肺内细胞凋亡的状况及其在肺损伤发病机制中的意义。方法：以不同浓度牛磺胆酸钠液逆行胰胆管注射造成大急急性水肿性胰腺炎（AEP)与急性坏死性胰腺炎(ANP)两种模型，测定血浆TNF-α与内毒素水平的动态变化，免疫组化检测肺内TNF-α的表达，并以TUNEL法结合激光扫描共聚焦显微镜检测肺组织切片内细胞凋亡的情况。结果：正常时大鼠肺内偶见淋巴细胞及纤维母细胞等发生凋亡，诱导AEP或ANP后凋亡细胞数量无明显变化。随着肺损伤的出现，少许浸润的炎细胞、肺泡上皮细胞及血管内皮细胞等发生了凋亡。凋亡指数(‰)在ANP组呈一过性下降，在ANP组表现为持续下降，在6h后各时点均显著低于AEP组相应值(P＜0．05)。分析表明，ANP组血中TNF-α、内毒素含量的增加与凋亡指数的变化存在负相关(P＜0.05)。结论：ANP时肺内浸润的以中性粒细胞为代表的大量炎细胞出现延迟凋亡，这种现象可能是肺损伤发生的重要前提，同时内毒素血症及TNF-α的过度合成可能是中性粒细胞延迟凋亡的部分原因。     

Development of cranial flexure and Rathke's pouch in the chick embryo

Experiments were done to investigate the cause of the cranial (mesencephalic) flexure of the chick brain during stages 10 to 14. Measurements of the length and thickness of the roof and floor of the mesencephalon gave values similar to the values obtained previously by others. The labeling index was determined in the roof and floor of the prosencephalon, mesencephalon, and rhombencephalon as a preliminary measure of cell division. The labeling index was about the same in all regions, and was high enough to suggest that most of the cells were dividing. The labeling indices did not suggest that differential growth was caused by differential rates of cell division in the roof and floor of the mesencephalon. It was found through time lapse photography that the foregut and heart remained stationary along the rostrocaudal axis, whereas the prosencephalon moved rostrally and the mesencephalon underwent flexure. Measurements suggested that the neural tube cranial to the otic primordium grew in volume exponentially at a rate consistent with the labeling index. The rostral tip of the neural tube was observed to be linked to the rostral tip of the foregut by the ectoderm that formed Rathke's pouch at the neural tube and the pharyngeal membrane (prospective stomodeum) at the foregut. As the neural tube grew in length, the link between the neural tube and the foregut did not. We suggest that because of this link, the growing neural tube had to bend around the foregut, forming the cranial flexure, and the ectoderm folded where it attached to the prosencephalon, forming Rathke's pouch. © 1994 Wiley-Liss, Inc.     

TSG-6基因在3T3-L1脂肪细胞诱导分化中表达水平的变化

[目的] 探讨TSG-6基因在3T3-L1脂肪细胞诱导分化中表达水平的变化。[方法] 采用细胞培养和RT-PCR技术，检测细胞诱导分化不同时段脂肪细胞中TSG-6基因的表达水平。[结果] ①随着脂肪细胞逐渐分化成熟，TSG-6基因mRNA表达水平逐渐升高；②TSG-6基因表达水平除在细胞分化第0-2d、第3-5d和第7-10d各时段内差异无显著性(P＞0.05)外，其余各时段之间表达水平差异均有显著性(P＜0.05)。[结论] TSG-6基因与细胞分化以及脂原形成可能相关。     

舍格伦综合征唇腺组织的细胞凋亡观察

目的　通过观察舍格伦综合征唇腺组织细胞凋亡的变化 ,探讨细胞凋亡在舍格伦综合征中的作用。方法　用原位末端标记法检测 16例舍格伦综合征的唇腺病变组织中的凋亡细胞数 ,并以 4例正常唇腺作为对照。每例随机统计 5个高倍视野的凋亡细胞数 ,并求出平均值。结果　染色结果显示舍格伦综合征患者唇腺腺泡及导管上皮可见散在阳性凋亡细胞 ,平均值为 ( 8 0 2± 2 2 3 )个 /高倍视野 ,正常唇腺组织细胞中阳性凋亡细胞为 ( 1 12± 0 3 4)个 /高倍视野 ,两组间对比差异有显著性。 (P <0 .0 5 )。舍格伦综合征病例的唇腺组织中腺泡及导管上皮可见散在的阳性凋亡细胞 ,其数量显著多于正常对照组。结论　考虑细胞凋亡可能是舍格伦综合征涎腺组织破坏的重要原因。     

急性淋巴细胞白血病细胞分化与花生凝集素受体表达

用系列单抗与标记的花生凝集素（ＰＮＡ）对３８例急性淋巴细胞白血病（ＡＬＬ）细胞行免疫分型与确定分化阶段，检测ＡＬＬ细胞ＰＮＡ受体表达情况，与正常成熟淋巴细胞（ＮＭＬ）对照。发现Ｔ－ＡＬＬ，Ｎｏｎ－Ｔ－ＡＬＬ细胞大多表达ＰＮＡ受体，而ＮＭＬ细胞极少表达ＰＮＡ受体，两者有显著差别（Ｐ＜０．０１）。经神经氨酸酶（ＮＡ）预处理后，Ｎｏｎ－Ｔ－ＡＬＬ与ＮＭＬ细胞ＰＮＡ受体表达明显增加（Ｐ＜０．０５），以ＮＭＬ为甚，而Ｔ－ＡＬＬ细胞ＮＡ处理前后ＰＮＡ受体表达未见明显区别；ＡＬＬ细胞ＰＮＡ受体表达与细胞分化程度存在显著的等级相关（ｒ８＝－０．３５７，Ｐ＜０．０５）。结果表明ＡＬＬ细胞上大多存在Ｄ－半乳糖－β（１－３）－Ｎ－乙酰氨基半乳糖基（Ｄ－Ｇａｌ－β（１－３）－Ｎ－ＧａｌＮＡＣ）；ＡＬＬ细胞分化程度越高。细胞上Ｄ－Ｇａｌ－β（１－３）－Ｎ－ＧａｌＮＡＣ连接唾液酸末端越多。     

Sensitive Detection of p53 Gene Mutations in Esophageal Endoscopic Biopsy Specimens by Cell Sorting Combined with Polymerase Chain Reaction Single-strand Conformation Polymorphism Analysis

For the rapid and sensitive detection of p53 gene mutations in esophageal endoscopic biopsy specimens, we combined cell sorting with the polymerase chain reaction and single-strand conformation polymorphism (PCR-SSCP) analysis. Mutations in exons 5–8 of the p53 gene were investigated by FCR-SSCF analysis using 10³ sorted nuclei obtained from each endoscopic biopsy specimen of 16 patients with esophageal cancer. DNAs extracted from their respective surgical specimens were investigated by a conventional method of PCR-SSCP analysis. Mutations in the biopsy specimens were detected in 6 of the 12 aneuploid tumors but in none of the 4 diploid tumors. After tumor cell enrichment by cell sorting, one mutation in exon 8 became apparent, which could not be detected from the surgical specimen by a conventional method of PCR-SSCP analysis. This method should improve the sensitivity of detecting p53 gene mutations, and provides additional information concerning the DNA ploidy pattern in the tumors.     

硫酸多糖对体外人脐静脉内皮细胞损伤的保护作用

研究表明,硫酸多糖体外对多聚阳离子和氧自由基损伤的人脐静脉内皮细胞有保护作用。肝素、硫酸软骨素A抗多聚阳离子损伤作用比同浓度低分子肝素和甘糖酯强。肝素、硫酸软骨素A、甘糖酯抗氧自由基损伤作用优于同浓度低分子肝素。结果显示硫酸多糖有保护血管内皮的作用,其作用可能与所带阴离子基团有关。     

重组人生长激素在体外对人直肠癌细胞株HR8348增殖的影响

目的　探讨重组人生长激素 (rhGH )在体外对人直肠癌细胞增殖的影响。方法　实验分为对照组、rhGH组、奥沙利铂 (L OHP)组和rhGH +L OHP组 4组 ,利用体外细胞培养、MTT比色技术及流式细胞仪等方法 ,测定不同浓度的rhGH对人直肠癌细胞株HR83 48细胞倍增时间、细胞抑制率、细胞周期、增殖指数 (PI)和DNA抑制率的影响。结果　rhGH在体外不促进HR83 48细胞的分裂增殖 ,rhGH组与对照组比较 ,以及rhGH +L OHP组与L OHP组比较 ,其差异均无统计学意义 (P>0 .0 5 ) ;rhGH +L OHP组与对照组比较及rhGH +L OHP组与对应的rhGH组配对比较 ,细胞倍增时间明显延长 ,细胞抑制率增加 ,阻滞于G0 ～G1期的细胞数增加 ,S期和G2 ～M期细胞明显减少 ,PI明显降低 ,DNA抑制率显著升高 (P<0 .0 1,S期P<0 .0 5 )。结论　rhGH在体外不促进直肠癌细胞的分裂增殖。