胃肠道间质瘤的现状和未来

 胃肠间质瘤（GIST）已经成为实体瘤中从实验研究迅速过渡到临床应用的光辉典范，文章高度归纳和综述了GIST的诊治现状和未来发展，特别是对有关认识进行了深入的阐述。     

诱导骨髓间充质干细胞向软骨细胞分化的体外研究

目的 探讨转化生长因子β1（transforming growth factor β1，TGF—β1）、胰岛素样生长因子1（insulinlike growth factor1，IGF-1）在诱导骨髓间充质干细胞（marrow mesenchymal stem ceils，MSCs）向软骨细胞分化过程中的相互作用，并研究细胞密度对MSCs向软骨细胞分化的影响。方法 取健康昆明种小白鼠骨髓，用全骨髓贴壁法筛选获得MSCs，体外培养传代。采用特定的诱导培养使MSCs向软骨细胞分化，按培养基内添加生长因子的不同分成3个实验组和对照组。实验组分别为：TGF—β1＋IGF-1联合应用组（TGF—β1 10ng／ml、IGF-1 50ng／m1）；TGF—β1单独应用组（TGF—β1 10ng／m1）；IGF-1单独应用组（IGF-1 50ng／m1）；对照组不添加任何生长因子。TGF—β1＋IGF-1联合应用组于诱导14d和21d，分别进行甲苯胺蓝染色及免疫荧光双染法鉴定；于诱导7、14和21d各组分别提取诱导细胞总RNA，进行RT—PCR扩增，检测TGF—β1、IGF-1对诱导细胞Ⅱ型胶原表达量的影响；比较MSCs在平板培养及细胞团培养时，Ⅱ型胶原表达量的差异。结果TGF—β1＋IGF-1联合应用组诱导培养14d，诱导软骨细胞甲苯胺蓝染色呈阳性，免疫荧光染色可见诱导软骨细胞的细胞外基质含有Ⅱ型胶原。各组基因扩增产物的凝胶电泳可见，TGF—β1＋IGF-1联合应用组和TGF—β1单独应用组Ⅱ型胶原扩增片段呈阳性；IGF-1单独应用组和对照组，未见Ⅱ型胶原扩增条带；凝胶成像系统灰度扫描示Ⅱ型胶原表达量TGF—β1＋IGF-1联合应用组各时间点均比TGF—β1单独应用组明显增加（P〈0．05）。细胞团培养模式下，诱导细胞表达Ⅱ型胶原比平板培养模式更加显著。结论 MSCs向软骨细胞诱导分化时，IGF-1对TGF—β1有明显的促进作用；细胞培养密度提高有利于MSCs成软骨细胞表型。     

恒定磁场对骨组织中细胞影响的研究

目的阐明恒定磁场对成骨细胞和破骨细胞的生长和功能的影响和对骨髓基质细胞向成骨细胞方向分化的作用，从而在细胞水平较全面的解释磁场治疗骨质疏松的机理。方法利用体外原代培养的成骨细胞、破骨细胞和骨髓基质细胞，分别外加0．38T、0．48T恒定磁场处理后，观察恒定磁场对这三种细胞生长、分化和功能的影响。结果恒定磁场处理可促进骨髓基质细胞向成骨细胞方向分化，促进成骨细胞的增殖、分化及功能的表达，并且抑制破骨细胞的生长、分化和功能。结论恒定磁场促进骨组织的成骨作用，抑制骨分解，是其治疗骨质疏松良好效果的部分机制。     

骨髓基质干细胞与珊瑚复合物体内回植时间的研究

目的　探索骨髓基质干细胞和珊瑚复合物的体内回植时间。方法　骨髓基质干细胞经成骨诱导分化后与珊瑚复合 ,体外培养 1、3、5、7d时行相差显镜镜、扫描电镜观察 ,并行裸鼠皮下回植。结果　 3d时 ,骨髓基质干细胞与珊瑚达到较好的复合状态 ,皮下回植有新骨形成。结论骨髓基质干细胞与珊瑚复合后体外培养 3d时就可以体内回植。     

富血小板血浆PRP的体外骨诱导作用研究

目的 :探讨在体外培养中富血小板血浆 (Platelet -RichPlasma ,PRP)对骨髓基质细胞诱导成骨的影响。方法 :从自体静脉血中提取PRP ,配制成条件培养液 ,并作用于培养状态的骨髓基质细胞 ,染色检测细胞碱性磷酸酶表达情况 ,钙化结节形成率 ,放免法测定培养液中骨钙素的含量。结果 :骨髓基质细胞经诱导培养后 ,碱性磷酸酶、骨钙素表达明显增加。结论 :体外培养时 ,PRP可促进骨髓基质细胞的成骨分化。     

牙骨质基质和骨基质对骨髓基质细胞体外钙化的影响

目的：研究骨髓基质细咆任牙骨质和骨片表面生长细胞表型发育的情况。方法：将骨髓基质细胞与牙骨质片和股骨片在体外共同培养，分别在第7d、第28d进行形态学观察，并用放射免疫的方法测定上清液中骨钙素的含量。结果：骨髓基质细胞在牙骨质片和骨片表面生长良好，但细胞形态不同，两组上清液中均有骨钙素的生成，骨片组较牙骨质片组的含量高，第28d骨钙素分泌量高于7d。结论：结果表明生长于牙骨质片和骨片表面的骨髓基质细胞在体外矿化液培养条件下可向成骨样细胞转化，但细胞表现型有所区别。     

碱性成纤维细胞生长因子对骨髓基质细胞增殖与成骨活性的影响

目的：观察碱性成纤维细胞生长因子(bFGF)对骨髓基质细胞的增殖及成骨活性的影响。方法：传代骨髓基质细胞的培养中加入不同浓度的bFGF，行细胞增殖和蛋白含量测定以及碱性磷酸酶的活性检测与钙结节的形成观察。结果：bFGF浓度在0～10ng／ml，蛋白含量及细胞数量随浓度的增高而增多，10ng／ml达到最大，浓度为100ng／ml反有下降。各组ALP活性没有降低，Von Kossa染色均为阳性。结论：bFGF可促进骨髓基质细胞的增殖，并保持骨髓基质细胞成骨的特性。     

16层螺旋CT在胃肠道间质瘤诊断中的价值

目的:探讨胃肠道间质瘤(GIST)16层螺旋CT表现及其诊断价值。方法:回顾性分析手术病理证实的GIST34例。术前行CT平扫2例,平扫加双期动态增强扫描32例。结果:34例中,良性5例,潜在恶性5例,恶性24例。肿瘤位于食道1例,胃22例,十二指肠1例,空、回肠5例,小肠系膜和结肠系膜各1例,复发2例,直肠1例。CT表现:黏膜下富血供肿块,倾向腔外生长,可有囊变、坏死、出血、钙化。增强后良性及潜在恶性GIST均匀强化,边界清楚,恶性GIST强化不均匀,可有邻近脏器侵犯。CT定性准确率29/34(85.29%),定位准确率30/34(85.24%)。结论:多层螺旋CT平扫加增强动态扫描是目前检查胃肠道间质瘤的一种最重要方法之一,能准确显示肿瘤的部位、形态、大小,有利于良恶性的判断,并对临床治疗及预测预后有着重要的指导价值。     

Bone alkaline phosphatase and prostate-specific antigen in the monitoring of prostate cancer

A retrospective study has been made on the interrelationship of serum bone alkaline phosphatase (BAP), measured by the Ostase-RIA, and prostate-specific antigen (PSA) in 156 patients with M0 and M1 prostate cancer. BAP is a more sensitive and more specific method of determining osteoblast activity than total alkaline phosphatase (TAP). The main difference between these two assays is seen when the TAP is in the range of normal to twice-normal. BAP shows a low intraindividual variation in M0 disease, and was within normal limits in 18 patients following radical prostatectomy with a PSA < 0.1 ng/ml. A raised BAP was observed in 86.4% of M1 disease at diagnosis before treatment. The change of BAP was concordant with PSA in 69% of 49 cases of M1 disease, although there are marked differences in the rates of change of the two markers. A nadir of PSA ? 10 ng/ml after androgen blockade in M1 disease was associated with a high probability of a normal BAP. © 1994 Wiley-Liss, Inc.     

Isolation of murine cementoblasts: unique cells or uniquely-positioned osteoblasts?

While cementoblasts express a number of mineral-related proteins, including bone sialoprotein (BSP), osteopontin (OPN) and osteocalcin (OC), these proteins do not appear to be expressed by cells of the intermediate dental follicle/periodontal ligament (PDL). This information was utilized in an experimental strategy to isolate presumptive cementoblasts from the root surface of day 24 murine mandibular first molars. Using microscopic dissection techniques, molars were carefully extracted from their alveolar crypts and subjected to trypsin-collagenase digestion to remove adherent cells. Primary cultures were established and assayed for expression of proteins known to be expressed by cementoblasts at this timepoint in vivo (i.e. BSP, OPN, OC) and also an odontoblast-specific protein (i.e. DSP) to rule out contamination by pulpal cells. A subgroup of cells were found to express Type I collagen (89% of cells), BSP (46%), OPN (23%) and OC (30%); DSP was not detected within these cultures. We propose that cells within this heterogeneous population, which express this profile of osteogenic proteins, represent cementoblasts. The availability of a cementoblast cell line will make possible rigorous and controlled in vitro analysis of these cells and allow for determination of the unique characteristics of these cells not shared with other cells, particularly osteoblasts.