诱导转化人关节软骨细胞Ⅱ型胶原表型的有效方式

背量：诱导去分化软骨细胞重新表达Ⅱ型胶原主要基于软琼脂悬浮培养法。目的：用离心管聚集体培养(aggregate culture)诱导去分化转化人关节细胞的Ⅱ型胶原。设计：非随机非对照实验研究。地点和对象：实验在第三军医大学西南医院骨科完成，对象为转化人关节软骨细胞，美国Hyclone公司产品。干预：将体外长期培养韵第30，40，50代去分化转化软骨细胞消化后进行离心管培养，比较细胞在单层培养、离心管聚集体培养，以及在普通培养基，BAI诱导培养基下[2型骨形态发生蛋白(BMP-2) 抗坏血酸盐 胰岛素]，Ⅰ，Ⅱ，Ⅲ型胶原的表达和胞外基质产生情况。主要观察指标：Ⅰ，Ⅱ，Ⅲ型胶原的免疫组化染色，Ⅱ型胶原的mRNA表达。结果：在单层培养条件下，去分化转化软骨细胞只表达Ⅰ型胶原，而在BAI诱导培养基及离心管聚集体培养下该转化软骨细胞表达丰富的Ⅱ型胶原和大量胞外基质。结论：离心管聚集体培养和BAI诱导培养基是诱导去分化转化软骨细胞Ⅱ型胶原的有效方式。     

流体剪切力影响人关节软骨细胞合成Ⅱ型胶原的研究

目的检测体外培养的人关节软骨细胞在不同大小的间断剪切力作用下合成Ⅱ型胶原的能力。 方法选取培养的软骨组织,按摇床作用的转速分为：空白对照组和低、中等、高转速组（转速分别为20、40、60转/min）;通过免疫组化法检测关节软骨细胞Ⅱ型胶原蛋白的表达,RT-PCR法检测Ⅱ型胶原mRNA表达。 结果中等转速组和高转速组Ⅱ型胶原免疫组化平均光密度（OD）值分别为(0.3061±0.0530)和(0.3777±0.0397),均高于低转速组平均OD值(0.2184±0.0135)和空白对照组平均OD值(0.1846±0.0363),差异均有统计学意义（P<0.05）;低、中等、高转速组Ⅱ型胶原mRNA OD比值分别为(0.120±0.003)、(0.150±0.005)、(0.210±0.006),均高于空白对照组OD比值(0.080±0.006),差异均有统计学意义（P<0.05）。 结论一定强度间断剪切力能够影响人软骨细胞的代谢、增殖活动,使其合成Ⅱ型胶原增多。     

TGF-β3诱导骨髓间充质干细胞表达软骨细胞表型的实验研究

目的探讨TGF-β3体外诱导骨髓间充质干细胞分化为软骨细胞的可行性。方法分离培养骨髓间充质干细胞,鉴定其表面抗原,用含10%胎牛血清以及10ng/mL转化生长因子TGF-β3的条件培养基诱导,诱导后细胞通过软骨细胞特征性染色鉴定。结果骨髓间充质干细胞表面抗原CD29、CD44、CD105阳性,CD34、CD45、CD106以及HLA-DR阴性。诱导后细胞形态明显改变,甲苯氨蓝以及Ⅱ型胶原染色结果阳性。结论TGF-β3具有促进骨髓间充质干细胞在体外分化为软骨细胞的能力,可以作为组织工程种子细胞的一种有效来源。     

软骨细胞形态、表型与胞间通讯的研究

背景：在体外培养时软骨细胞会像成纤维细胞样成片生长并失去表型，软骨细胞胞间通讯与细胞表型的关系尚无报告。目的：了解体外培养的不同形态的软骨细胞的增殖、基质合成、荧光染料摄入以及缝隙连接的关系。设计：以诊断为依据的实验研究。地点和对象：实验在解放军总医院骨科研究所和基础研究所完成，实验对象为兔关节软骨细胞，人股骨头软骨。干预：体外培养的兔软骨细胞，分别进行苏木精一伊红(HE)、亮绿一藩红花O染色，显微镜下测量细胞大小、激光共聚焦显微镜下测量细胞内的荧光强度。激光淬灭软骨细胞内的荧光染料。主要观察指标：软骨细胞的外观、细胞大小、细胞内的荧光强度。结果：细胞投影面积测量：软骨细胞变大，失去球形外观后增殖加快，平均面积1755．1μm^2，投影面积差别可达50倍。基质合成消失，缝隙连接消失。显微镜下软骨细胞的荧光强度测量：球形软骨细胞CFDA-AM摄人多，(平均2057／30个细胞)，扁平细胞摄入少(平均83／30个细胞)。体外培养的球形兔软骨细胞间，人关节软骨生发层陷窝内的细胞间有胞间通讯。结论：软骨细胞的密度、形态、表型和缝隙连接之间有一定的关系。而细胞外形可能决定细胞的表型。     

软骨细胞形态、表型与胞间通讯的研究

背景在体外培养时软骨细胞会像成纤维细胞样成片生长并失去表型,软骨细胞胞间通讯与细胞表型的关系尚无报告.目的了解体外培养的不同形态的软骨细胞的增殖、基质合成、荧光染料摄入以及缝隙连接的关系.设计以诊断为依据的实验研究.地点和对象实验在解放军总医院骨科研究所和基础研究所完成,实验对象为兔关节软骨细胞,人股骨头软骨.干预体外培养的兔软骨细胞,分别进行苏木精-伊红(HE)、亮绿-藩红花O染色,显微镜下测量细胞大小、激光共聚焦显微镜下测量细胞内的荧光强度.激光淬灭软骨细胞内的荧光染料.主要观察指标软骨细胞的外观、细胞大小、细胞内的荧光强度.结果细胞投影面积测量软骨细胞变大,失去球形外观后增殖加快,平均面积1755.1 μm2,投影面积差别可达50倍.基质合成消失,缝隙连接消失.显微镜下软骨细胞的荧光强度测量球形软骨细胞CFDA-AM摄入多,(平均2057/30个细胞),扁平细胞摄入少(平均83/30个细胞).体外培养的球形兔软骨细胞间,人关节软骨生发层陷窝内的细胞间有胞间通讯.结论软骨细胞的密度、形态、表型和缝隙连接之间有一定的关系.而细胞外形可能决定细胞的表型.     

转化软骨细胞与正常软骨细胞的生物特性比较

目的比较转化人关节软骨细胞与正常软骨细胞之间的生物特性。方法观察两者的细胞形态、细胞的生长曲线、血清依赖性、染色体检查、软琼脂克隆形成试验、裸鼠致瘤性。结果转化软骨细胞更趋向于长梭形。两者的生长曲线比较相似,但转化软骨细胞的饱和密度要明显高于正常软骨细胞。两者都对血清有依赖性,都为二倍体核型,均不能在软琼脂上形成克隆。经6个月观察两者都不能使裸鼠致瘤。结论转化软骨细胞的生长速度要高于正常软骨细胞。转化软骨细胞为良性转化。     

兔关节软骨细胞在藻酸盐串珠中培养维持其表型稳定的研究

目的：软骨细胞在单层培养时，多次传代后细胞表型发生改变。将兔关节软骨细胞在藻酸盐串珠中作立体培养，以保持其特有表型。方法：用酶消化法获取兔关节软骨细胞，分别在普通培养瓶中作贴壁的单层培养，并传代；或制成细胞/藻酸盐悬液，再进一步制成串珠，使细胞在具有三维立体结构的串珠中生长、繁殖。细胞涂片、石蜡切片，受尔新蓝染色，采用倒置微镜、透射电镜观察；以RT-PCR方法检测软骨细胞中Ⅱ型胶原及凝集聚糖mRNA的表达。结果：单层培养时有较高的细胞增殖率，5代以后渐失去软骨细胞特有的表型。立体培养时细胞分泌的基质大部分位于自身的周围，特有表型可长期保持稳定。3个月后藻酸盐串珠中的软骨细胞仍可测得Ⅱ型胶原和凝集聚糖的表达。结论：软骨细胞在藻酸盐串珠中培养有助于其合成、分泌基质，维持细胞特有表型的稳定。     

转化软骨细胞与正常软骨细胞的生物特性比较

目的 比较转化人关节软骨细胞与正常软骨细胞之间的生物特性。方法 观察两者的细胞形态、细胞的生长曲线、血清依赖性、梁色体检查、软琼脂克隆形成试验、裸鼠致瘤性。结果 转化软骨细胞更趋向于长梭形。两者的生长曲线比较相似，但转化软骨细胞的饱和密度要明显高于正常软骨细胞。两者都对血清有依赖性、都为二倍体核型，均不能在软琼脂上形成克隆。经6个月观察两者都不能使裸鼠致瘤。结论 转化软骨细胞的生长速度要高于正常软骨细胞。转化软骨细胞为良性转化。     

骨髓间充质干细胞和关节软骨细胞共培养与转化生长因子β1诱导的比较

背景:应用生长因子可诱导骨髓间充质干细胞向软骨样细胞分化,但诱导后的细胞在生物体内很难形成成熟的软骨细胞且仍具有分泌软骨基质及抗压,抗摩擦的能力.目的:对比分析骨髓间充质干细胞与关节软骨细胞共培养诱导、转化生长因子β1诱导骨髓间充质干细胞的效果.方法:提取SD大鼠关节软骨细胞与第3代骨髓间充质干细胞,按1:2,1:1,2:1浓度比种植于Transwell共培养系统中.同时设置转化生长因子β1诱导组为对照.相差显微镜下观察细胞的增殖和基质合成情况,并诱导结果行MTT比色法检查、氨基聚糖水平检测及Western Blot检测II型胶原基因的表达情况.结果与结论:关节软骨细胞与骨髓间充质干细胞1:2比例诱导的结果与10 μg/L转化生长因子β1诱导结果相当,但随着关节软骨细胞在诱导中体系中比例的增加,诱导结果明显优于转化生长因子β1诱导,当诱导细胞达到一定比例时,诱导结果不会随之变化.说明软骨细胞与骨髓间充质干细胞共培养可以诱导骨髓间充质干细胞向软骨细胞转化,在开始时,诱导结果与软骨细胞所占的比例成正相关,当软骨细胞达到一定比例时, 骨髓间充质干细胞的诱导结果并未发生明显变化,提示骨髓间充质干细胞对软骨细胞的诱导存在饱和现象.     

胰蛋白酶及Ⅱ型胶原酶消化获取关节软骨细胞

背景:近年来,众多研究欲采用体外分离培养的关节软骨细胞作为修复缺损的关节软骨的种子细胞,然而,获得纯化的具有生物活性的关节软骨细胞较为困难.目的:拟运用胰蛋白酶与Ⅱ型胶原酶联合消化获取关节软骨细胞.方法:从SD大鼠的正常股骨及胫骨关节表面获取关节软骨,先后运用0.25%的胰蛋白酶和0.2%Ⅱ型胶原酶消化,显微镜下见大量细胞游离后,弃去大块的未消化的关节软骨碎片,离心,去上清,PBS洗涤2次后,加入软骨细胞原代培养液进行培养、增殖.应用甲苯胺蓝及苏木精-伊红染色方法检验所得细胞是否为关节软骨细胞.结果与结论:在严格掌握酶的浓度及消化时间的前提下,通过0.25%胰蛋白酶和0.2%Ⅱ型胶原酶联合酶解关节软骨的方法,成功从大鼠股骨及胫骨关节软骨内分离培养出细胞,并经过甲苯胺蓝染色及苏木精-伊红染色证实,所得的细胞为具有生物活性的关节软骨细胞.     

Induction of arthritis in monkeys by immunization with type II collagen

Immunization of two cynomolugus and three rhesus monkeys with purified type II collagen resulted in the development of polyarthritis. Arthritis first became clinically apparent 7 wk after primary immunization and persisted for 16 mo. Radiologic examination of the limbs demonstrated soft tissue swelling with severe joint destruction including loss of cartilage and bone. Involved joints eventually became ankylosed with permanent loss of some motion. All of the monkeys developed a response to the immunizing collagen as determined by ELISA of serum for antibodies. Arthritis was associated with weight loss and constitutional symptoms, including lethargy and refusal to eat. One monkey became so debilitated that it was necessary to euthanize it. Histologic examination of the joints showed synovial hypertrophy with pannus formation. A control monkey immunized with type I collagen suffered no apparent ill effects.     

Induction of cellular immunosuppression by the human papillomavirus type 16 E7 oncogenic protein.

The human papillomavirus type 16 (HPV-16) E7 oncogenic protein is found in the culture supernatant of SiHa cells, a cervical carcinoma cell line. Extracellular E7 protein, acting as a viral toxin in human immune cells, induces the overproduction of the immune suppressive IFN alpha cytokine by APCs, and inhibits the T-cell response to recall and allogenic antigens. These effects should be taken into account for the design of anti-human cervical carcinoma vaccines.     

Induction of dermal-epidermal separation in mice by passive transfer of antibodies specific to type VII collagen

Epidermolysis bullosa acquisita (EBA) is a subepidermal blistering disorder associated with tissue-bound and circulating autoantibodies specific to type VII collagen, a major constituent of the dermal-epidermal junction. Previous attempts to transfer the disease by injection of patient autoantibodies into mice have been unsuccessful. To study the pathogenic relevance of antibodies specific to type VII collagen in vivo, we generated and characterized rabbit antibodies specific to a murine form of this antigen and passively transferred them into adult nude, BALB/c, and C57BL/6 mice. Immune rabbit IgG bound to the lamina densa of murine skin and immunoblotted type VII collagen. Mice injected with purified IgG specific to type VII collagen, in contrast to control mice, developed subepidermal skin blisters, reproducing the human disease at the clinical, histological, electron microscopical, and immunopathological levels. Titers of rabbit IgG in the serum of mice correlated with the extent of the disease. F(ab')(2) fragments of rabbit IgG specific to type VII collagen were not pathogenic. When injected into C5-deficient mice, antibodies specific to type VII collagen failed to induce the disease, whereas C5-sufficient mice were susceptible to blister induction. This animal model for EBA should facilitate further dissection of the pathogenesis of this disease and development of new therapeutic strategies.     

Induction of monocyte procoagulant activity by murine hepatitis virus type 3 parallels disease susceptibility in mice

The in vitro induction of procoagulant activity (PCA) in murine peripheral blood mononuclear cells (PBM) by murine hepatitis virus type 3 (MHV-3) correlates with the disease susceptibility in three strains of mice. PBM from BALB/c mice, a strain in which MHV-3 infection results in fatal acute fulminant hepatitis, responds to the virus with a robust PCA response, whereas PBM from C3H/St mice, a strain which develops mild acute hepatitis followed by chronic hepatitis, only exhibit a modest PCA response. In contrast, PBM from A/J mice, a strain fully resistant to MHV-3, generate no increase in PCA above control levels. The induction phase of MHV-3 PCA is rapid, with an increase within 1-1.5 h, with maximum activity at 18h, and it precedes MHV-3 replication in either 17 CL1 cells, a fully permissive cell line, or in monocytes from these strains of mice. The PCA response of BALB/c PBM exceeds the response to any other known stimulus. No induction occurs upon direct stimulation of monocytes by MHV-3, but in the presence of lymphocyte collaboration, the PCA response is observed first at a lymphocyte:monocyte ratio of 2:1 and reaches a maximum as the lymphocyte:monocyte ratio approaches 4:1. This response appears to provide a functional marker for susceptibility to MHV-3 infection in inbred strains of mice and could be important in the pathogenesis of MHV-3-induced disease.     

Induction of immunity against lethal Haemophilus influenzae type b infection by Escherichia coli core lipopolysaccharide.

Efforts to prevent Haemophilus influenzae type b (HIB) infections in infancy have been hampered by the low immunogenicity of capsular polysaccharide vaccines in children younger than 18 mos. In searching for alternate immunogens, we have studied the protective potential of polysaccharide-poor, lipid-rich endotoxin (LPS) core in experimental HIB infections. Because all gram-negative bacteria have similar LPS core structures, we were able to use as vaccine the J5 mutant of Escherichia coli 0111, the LPS of which consists only of core components, and thus to avoid problems in interpretation arising from vaccine contamination with non-LPS HIB immunogens. Mice were given graded inocula of HIB and developed lethal infection analogous to human HIB disease when virulence was enhanced with mucin and hemoglobin. After active immunization with heat-killed E. coli J5, 40/50 (80%) of infected mice survived, compared with 14/50 (28%) of saline-immunized controls (P less than 0.005). Passive immunization with rabbit antiserum against E. coli J5 prevented lethal HIB infection when administered 24 or 72 h before or 3 h after infection. This protection was abolished by adsorption of antiserum with purified J5 LPS, with survival reduced from 14/24 to 0/24 (P less than 0.005). Furthermore, rabbit antiserum to purified J5 LPS gave just as potent protection against death as antiserum to whole J5 cells. These studies demonstrate that immunity to core LPS confers protection against experimental murine HIB infection and provide the framework for a new approach to prevention of human disease from HIB.     

Induction of Labor

In order that patients with gastrointestinal carcinoma achieve a maximum survival rate, it is necessary to adopt a prudent attitude of optimism, not only toward those with early lesions but also those who appear to have advanced disease. Eight cases are reviewed in which the patients, following radical surgery, are enjoying long periods of survival, even though the initial clinical picture seemed hopeless.