摘要：Background： A major shortcoming in tissue engineered blood vessels （TEBVs） is the lack of healthy and easily attainable smooth muscle cells （SMCs）. Smooth muscle progenitor cells （SPCs）, especially from peripheral blood, may offer an alternative cell source for tissue engineering involving a less invasive harvesting technique. Methods： SPCs were isolated from 5-ml fresh rat peripheral blood by density-gradient centrifugation and cultured for 3 weeks in endothelial growth medium-2-MV （EGM-2-MV） medium containing platelet-derived growth factoroBB （PDGF BB）. Before seeded on the synthesized scaffold, SPC-derived smooth muscle outgrowth cell （SOC） phenotypes were assessed by immuno-fluorescent staining, Western blot analysis, and reverse transcription polymerase chain reaction （RT-PCR）. The cells were seeded onto the silk fibroin-modified poly（3-hydroxybutyrate-co-3-hydroxyhexanoate） （SF-PHBHHx） scaflblds by 6× 10^4 cells/cm^2 and cultured under the static condition for 3 weeks. The growth and proliferation of the seeded cells on the scaffold were analyzed by 3-（4,5-dimethylthiazol-2-yl）-diphenyltetrazolium bromide （MTT） assay, scanning electron microscope （SEM）, and 4,6-diamidino-2-phenylindole （DAPI） staining. Results： SOCs displayed specific ＂hill and valley＂ morphology, expressed the specific markers of the SMC lineage： smooth muscle （SM） a-actin, calponin and smooth muscle myosin heavy chain （SM MHC） at protein and messenger ribonucleic acid （mRNA） levels. RT-PCR results demonstrate that SOCs also expressed smooth muscle protein 22a （SM22a, a contractile protein, and extracellular matrix components elastin and matrix Gla protein （MGP）, as well as vascular endothelial growth factor （VEGF）. After seeded on the SF-PHBHHx scaffold, the cells showed excellent metabolic activity and proliferation. Conclusion： SPCs isolated from peripheral blood can be differentiated the SMCs in vitro and have an impressive growth potential in the biodegradable synthesized scaffold. Thus,

摘要：青藏高原作为印度季风与西风交汇的特殊区域,对全球气候变化响应敏感,成为了古气候研究的热点地区。青藏高原湖泊众多,存在巨厚连续的湖泊沉积物,为古气候重建提供了优良载体。而介形类壳体在湖泊中沉积连续,生长过程记录了气候变化,同时有效屏蔽了湖泊水体中同位素的累积效应,能够反映介壳生长阶段短时间尺度的同位素水平,理论上是高精度气候重建的理想载体。基于此,本研究选取青藏高原中部地区湖泊色林错湖芯(SL16-1-1)顶部0~107cm部分为对象,对其中的介形类壳体进行种属鉴定及碳氧同位素分析,以期建立高分辨率的古环境变化记录,结合沉积物Rb/Sr、Ti/Si环境代用指标,重建色林错湖区近2000年来的气候变化记录,结果揭示了:1)介形类壳体碳氧稳定同位素变化对气候变化(尤其冷气候)尤为敏感,是重建高分辨率环境变化过程的优良载体;2)色林错地区对小冰期冷事件的响应较早于其他地区;3)色林错介形类壳体2000年来的气候重建结果与青藏高原研究成果大体一致,特别是与内地文献记录和物候史料记载高度一致,说明色林错湖泊记录具有广泛代表性,同时证实利用湖泊沉积物介形类壳体进行古气候高分辨率重建具有可靠性。

摘要：背景:内皮细胞和平滑肌细胞的相互调节是稳定血管壁结构的关键因素,两者共同培养能够分别影响各自的形态和功能。目的:利用Ⅰ型胶原浮胶建立人脐静脉内皮细胞与人血管平滑肌细胞共培养体系,分析细胞之间的相互作用。设计、时间及地点:单一样本观察,于2006-10/2008-01在复旦大学上海医学院分子生物学实验室完成。材料:新鲜脐带取自国际第一妇婴保健医院,产妇知情同意。方法:取新鲜脐带,利用胶原酶灌注法分离人脐静脉内皮细胞,组织块培养法分离人血管平滑肌细胞。人血管平滑肌细胞直接种植于培养板表面,人脐静脉内皮细胞种植于鼠尾Ⅰ型胶原表面制成胶原浮胶,并与培养板上的人血管平滑肌细胞共培养。以人脐静脉内皮细胞单独在浮胶底面培养,培养板表面无人血管平滑肌细胞为对照。主要观察指标:①免疫荧光方法鉴定人血管平滑肌细胞和人脐静脉内皮细胞。光镜和电镜观察人脐静脉内皮细胞形态。②反转录-聚合酶链反应进行基因表达分析。结果:原代培养的内皮细胞呈铺路石样形态,CD31染色阳性。原代培养的人血管平滑肌细胞免疫荧光染色α-SMA呈阳性。胶原支架上内皮细胞伸展,胶原纤维重新排列,24h后出现管腔样结构。在共培养体系中,人脐静脉内皮细胞的金属蛋白酶1和金属蛋白酶9基因表达量显著高于单独培养组人脐静脉内皮细胞的表达量(P<0.05)。但层粘蛋白γ2和组织因子途径抑制物2的基因相对表达量在两组间未见明显变化。结论:实验建立的共培养体系,可以观察到与平滑肌细胞共培养的血管内皮细胞形成更加丰富的网络状管腔样结构,更易于血管结构的形成。