机械拉伸波形及频率对肺腺癌细胞增殖的影响

通过FX-4000柔性基底加载系统研究了不同波形及频率的周期性机械拉伸对人肺腺癌A 549细胞株增殖的影响,应用Im age-P ro图像处理软件对A 549细胞株在心形波、三角波及方波等拉伸应变下的增殖动力学变化进行了分析。实验表明:在co llagenⅠ基底膜上,应变0-25%,频率为20次/m in、40次/m in及60次/m in,加载时间为2 h时,与对照组比较,方波刺激组细胞生长明显受到抑制,三角波刺激组细胞增殖率无明显差异,心形波刺激组细胞增殖加快。研究表明:A 549细胞株对体外的生理应变作出响应时,方波与60次/m in频率的组合刺激抑制作用最佳,且加载时间越长抑制效果越好。可见,波形与频率的合理组合在抑制人肺腺癌细胞增殖的过程中起着重要作用。     

周期性拉伸应力与人永生化角质形成细胞的黏附和铺展

背景：皮肤组织所处的力学环境以及上皮细胞的铺展状态与伤口愈合和瘢痕形成过程关系密切。 目的：分析胞外力学刺激对细胞铺展的作用,并检测细胞的增殖状态进一步分析铺展形态对细胞增殖等生理活动的影响。 方法：通过FX-4000柔性基底加载系统对人永生化角质形成细胞(HaCaT)进行周期性拉伸应力正弦波加载,加载程式0.2 Hz,10%拉伸幅度。在0,24,48 h对细胞的铺展形态进行对比,利用流式细胞仪检测分析细胞的增殖,并利用免疫荧光染色方法对比分析纽蛋白在细胞内的分布。 结果与结论：HaCaT细胞在加载24 h后分裂期细胞较多,铺展形态无明显变化;加载48 h后HaCaT细胞形态发生较为明显的变化,分裂期细胞较静态对照组略有减少;拉伸应力作用下纽蛋白的分布由细胞核周围的膜区域向细胞边缘集中。结果表明：适度的力学加载能够在保持细胞铺展和黏附状态下,促进细胞增殖;周期性持续拉伸应力的作用时间是HaCaT细胞铺展形态和与基底黏附位点的重要影响因素。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

短期机械拉伸加载对人肺腺癌细胞A549细胞的增殖效应

目的测量人肺腺癌细胞株A549对机械拉伸加载的短期响应。方法用加载Flexercell-4000TTM系统在4h内对A549细胞进行正常生理参数范围的应变刺激,并测量细胞的增殖效应。结果细胞的增殖率均有不同程度的提高,增殖响应系数M(%)为:0.5h,M=18%;1h,M=22%;4h,M=5%。结论研究证明细胞对短期加载的增殖响应与人成骨细胞特征相似,在1800循环数左右有一峰值,间歇式加载能保持长期高增长率,而过去的研究表明连续加载相反,只会抑制细胞的增长。     

正弦波刺激对人肺腺癌细胞粘弹性的影响

目的通过FX-4000柔性基底加载系统研究正弦波拉伸培养对体外人肺腺癌A549细胞粘弹性的影响。方法采用微管吸吮技术考察A549细胞的粘弹性特性,将不同拉伸幅度培养下的A549细胞与对照组细胞粘弹性进行对照,选择三参数标准线性固体模型拟合实验结果并用三个粘弹性系数比较各组A549细胞的力学性质。结果在胶原蛋白基底膜上,正弦波、频率0.5Hz、加载4h时,与对照组比较,15%的拉伸应变组A549细胞的粘弹性系数k_1、k_2和μ值均有所降低;与1.5%的拉伸应变组A549细胞的粘弹性系数比较无明显差异。结论15%的拉伸应变刺激培养后A549细胞更容易变形,细胞刚性有所减小。癌细胞粘弹性的改变可能影响到浸润和转移特性以及癌细胞与其微观力学环境的相互作用。     

肺腺癌细胞三维培养对HOXC10基因表达水平的影响

目的 建立肺腺癌A549细胞株三维培养模型，观察和比较二维和三维不同培养条件下肺腺癌细胞的形态、增殖以及HOXC10表达水平的变化。方法 二维和三维培养肺腺癌细胞，采用倒置显微镜观察肺腺癌细胞的生长情况，通过CCK8实验检测细胞增殖情况，Real time-PCR和Western blot方法检测HOXC10 mRNA和蛋白表达水平。结果 二维单层培养的肺腺癌A549细胞贴壁生长，癌细胞呈梭形。三维细胞培养后，肺腺癌细胞聚集成紧密的多肿瘤细胞微球。HOXC10基因mRNA和蛋白质表达水平在A549细胞三维培养显著高于二维培养。结论 HOXC10基因表达在肺腺癌A549细胞三维培养体系显著升高，可能与肿瘤微环境的作用密切相关。     

靶向阻断LRP提高肺腺癌细胞对紫杉醇的敏感性

目的利用小干扰RNA(siRNA)技术沉默肺腺癌细胞肺耐药相关蛋白基因(LRP),探讨其对肺腺癌紫杉醇耐药株(A549/TXL20)紫杉醇(TXL)敏感性的影响。方法逐步增加药物浓度法建立A549紫杉醇耐药细胞株(A549/TXL20),用小干扰RNA技术沉默LRP在A549/TXL20细胞中的表达,以MTT法检测紫杉醇对A549/TXL20细胞的半数抑制浓度(IC50);以q PCR检测细胞中LRP mRNA的表达,Western blot检测细胞中LRP蛋白的水平,裸鼠腋窝皮下注射转染后的A549/TXL20细胞,建立裸鼠移植瘤模型,观察LRP靶向siRNA对人肺腺癌耐药细胞株A549/TXL20移植瘤耐药的影响。结果肺腺癌紫杉醇耐药株(A549/TXL20)对紫杉醇的敏感性明显增强(P0.01),A549/TXL20细胞中LRP mRNA及蛋白表达显著增加(P0.01);siRNA沉默A549/TXL20细胞LRP基因后,与空白组和空质粒组比较,LRP mRNA及蛋白表达均被抑制(P0.01);小干扰RNA可提高荷瘤裸鼠对紫杉醇的敏感性。结论 siRNA可有效沉默A549/TXL20肺腺癌耐药细胞株LRP基因的表达,提高耐药的肺腺癌细胞对紫杉醇的敏感性。     

PLCE1通过调控p53抑制肺腺癌A549细胞凋亡

目的:探讨磷脂酶Cε1(PLCE1)抑制肺腺癌A549细胞凋亡的作用机制。方法:选用人肺腺癌细胞株A549作为研究对象。采用real-time PCR和Western blotting法分别检测PLCE1抑制剂U-73122处理前、后肺腺癌细胞株A549中PLCE1和p53 mRNA和蛋白水平的表达;流式细胞术检测细胞凋亡。结果:肺腺癌细胞株A549高表达PLCE1,低表达p53;抑制PLCE1表达后A549细胞中p53表达上调,细胞凋亡明显增加。结论:PLCE1通过抑制肺腺癌A549细胞株中p53的表达,从而抑制A549细胞凋亡。     

间歇性机械拉伸对体外培养兔关节软骨细胞微管蛋白-β取向的影响

目的探讨间歇性机械拉伸对兔关节软骨细胞生长和细胞形态及骨架的影响,为软骨细胞内力学信号传导研究的提供参考。方法采用FX-4000TM柔性基底拉伸系统对体外单层原代培养的兔软骨细胞实施正弦波、0.5Hz、05%间歇性周期应变加载,每日拉伸3h,共加载3天。对照组静态培养。3天后检测细胞活力、基质合成情况以及微管蛋白-β细胞免疫荧光染色,并对细胞周期进行检测。结果加载组软骨细胞生长良好,氨基多聚糖和蛋白多糖的合成与对照组无明显差异;但细胞增殖指数显著增高(P<0.05);微管蛋白-β沿细胞长轴发生重排,细胞形态和取向趋于一致。结论间歇性机械拉伸对细胞生长起到积极的作用,并且通过微管蛋白-β的重排影响细胞形态和取向。     

大鼠血管平滑肌细胞形态和DNA合成对基底膜周期性应变的响应

目的：探索基底膜伸张应变与血管平滑肌细胞（VSMC）增殖和重排的关系。了解融合和非融合细胞生长状况对应力作用的响应。方法：应用自行研制的基底膜伸张装置，模拟生理状况下血管平滑肌细胞受到的二维拉伸应变，通过基底膜伸张的单向循环加载方式，使膜上生长的细胞变形，结合显微形态观测。计算机图象处理，[甲基^3-氢]胸腺嘧啶核苷（^3H-TdR)掺入实验，综合考查应变对VSMC形态变化和DNA合成的影响，结果：（1）加载30′-6h细胞辅展面积进行性增加，6-24h细胞铺展面积缩小；（2）非融合生长的细胞随细胞增殖和加载时间延长。细胞排布处于调整变化中；（3）融合生长的细胞，加载10h后，细胞排布趋于稳定并呈平行排列，且有舒缩活动，（4）与对照组比较加载24h^3H-TdR掺入明显升高。结论：未融合生长的细胞对应变刺激的响应以细胞增殖为主，融合生长的细胞对应变刺激的响应以细胞重排为主。并表现组织特异功能一收缩活动。     

重组人IL-24联合顺铂体外抗肺癌细胞生长的实验研究

目的探讨重组人白细胞介素-24(rhIL-24)联合顺铂(DDP)对人肺腺癌A549细胞的体外抑制效应及对A549细胞凋亡、细胞周期的影响。方法 rhIL-24、DDP及rhIL-24+DDP干预A549细胞,用CCK-8法检测A549细胞增殖抑制率;用流式细胞仪检测细胞凋亡及细胞周期的变化。结果 rhIL-24联合DDP作用24 h对人肺腺癌A549细胞增殖抑制率为32.8%,与单独DDP组比较有显著性差异(P0.05);流式细胞仪检测rhIL-24联合DDP作用24 h对人肺腺癌A549细胞凋亡率为24.9%;细胞周期检测中rhIL-24作用A549细胞24 h后S期细胞增多。结论 rhIL-24能抑制A549细胞增殖,联合DDP组效果优于单独用药组,具有化疗增敏效应;rhIL-24能诱导A549细胞凋亡并能影响细胞周期。     

Asymmetry of the internal connections of the striate cortex of the cat in the projection zone of the center of the field of vision

Studies were carried out on the organization of the internal connections of the striate cortex in cats in the projection zone of the center (0–5°) of the field of vision by microintophoretic application of horseradish peroxidase to electrophysiologically identified orientational columns. The area containing neurons showing retrograde labeling in most cases extended in the mediolateral direction. Labeled cells were located in the upper (II, III) and lower (V, VI) layers of the cortex, and the shapes and orientations of the areas containing labeled neurons in these layers coincided. Spatial asymmetry was detected in the distribution of labeled neurons relative to the orientational column studied. Labeled cells were located predominantly medial to the columns, regardless of the distance from the projection of the area centralis. Considering the visuotopical map of field 17, the asymmetry detected here provides evidence that neurons in orientational columns have more extensive connections with neurons of the peripheral part of the cortex. An asymmetrical distribution of “silent” zones around the receptive fields of neurons in orientational columns is suggested, and that these appear to receive influences from the periphery of the visual field. Laboratory of Visual Physiology and Laboratory of Central Nervous System Morphology, I. P. Pavlov Institute of Physiology, Russian Academy of Sciences, 6 Makarov Bank, 199034 St. Petersburg, Russia. Translated from Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 82, No. 12, pp. 23–29, December, 1996.     

Effects of the lesion of the postcommissural part of the septum on the behavior of the rat.

The effects of the lesion of the postcommissural part of the septum on behavior of the rat has been studied. Results may be summarized as follows. An increase in the exploratory behavior in the open field which decreases rapidly; a decrease in the number of defecations in this test and a decrease in time leaving a dark environment for exploration. In the shuttle box test, no facilitation of the acquisition, but a permanent and quite significant increase in the intertrial activity has been found. We conclude that the lesions tend to decrease the emotivity of the subjects. An interpretation on the basis of the species -- specific defensive reactions explains the transitory and permanent effects of the lesions on the spontaneous activity.     

Counterpointing the functional role of the forebrain and of the brainstem in the control of the sleep-waking system

This paper reviews the lifetime contributions of the author to the field of sleep-wakefulness (S-W), reinterprets results of the early studies, and suggests new conclusions and perspectives. Long-term cats with mesencephalic transection show behavioral/polygraphic rapid eye movement sleep (REMS), including the typical oculo-pupillary behavior, even when the section is performed in kittens prior to S-W maturation. REMS can be induced as a reflex. Typical non-rapid eye movement S (NREMS) is absent and full W/arousal is present only after a precollicular section. The isolated forebrain (IF) rostral to the transection exhibits all features of W/arousal and NREMS [with electroencephalographic (EEG) spindles and delta waves], arousal to olfactory stimuli, and including the appropriate oculo-pupillary behaviors. These features also mature normally after neonatal transection. REMS is absent from the IF. After deprivation there is NREMS pressure and rebound in the IF, but the decerebrate cat only shows pressure for REMS. Most IF reactions to pharmacologic agents are within expectations, except for the tolerance/withdrawal effects of long-term morphine use which are absent. In contrast, these effects are supported by the brainstem (i.e. seen in the decerebrate cat). In cats with ablation of the telencephalon, or diencephalic cats, delta waves are absent in the thalamus. EEG thalamic spindle waves are seen triggering S for only 4-5 days after ablation. Therefore, true NREMS is absent in chronic diencephalic cats although pre- and postsomniac behaviors persist. These animals are hyperactive and show a pronounced, permanent insomnia; however, a low dose of barbiturate triggers a dramatic REMS/atypical NREMS rebound. Cats without the thalamus (athalamic cats), initially show a dissociation between behavioral hyperactivity/insomnia and the neocortical EEG, which for 15-20 days exhibits only delta and slower oscillations. Fast, low-voltage W rhythms appear later on, first during REMS, but spindle waves and S postures are absent from the start, such that these cats also display only atypical NREMS. Athalamic cats also show barbiturate-sensitive insomnia. Cats with ablation of the frontal cortices or the caudate nuclei remain permanently hyperactive. They also show a mild, but significant hyposomnia, which is permanent in afrontal cats, but lasts for about a month in acaudates. The polygraphic/behavioral features of their S-W states remain normal. We conclude and propose that: (a) the control of the S-W system is highly complex and distributed, but is organized hierarchically in a well-defined rostro-caudal manner; the rostral-most or highest level (telencephalon), is the most functionally complex/adaptative and regulates the lower levels; the diencephalic/basal forebrain, or middle level, has a pivotal role in inducing switching between S and W and in coordinating the lowest (brainstem) and highest levels; (b) W can occur independently in both the forebrain and brainstem, but true NREMS- and REMS-generating mechanisms exist exclusively in the forebrain and brainstem, respectively; (c) forebrain and brainstem S-W processes can operate independently from each other and are preprogrammed at birth; this helps understanding normal and abnormal polygraphic/behavioral dissociations in humans and normal dissociations/splitting in aquatic mammals; (d) NREMS homeostasis is present in the IF, but only REMS pressure after deprivation persists in the decerebrate cat; (e) the thalamus engages in both NREMS and W; (f) insomnia in diencephalic cats is the result of an imbalance between antagonistic W- and S-promoting cellular groups in the ventral brain (normally modulated by the telencephalon); (g) the EEG waves, which are signature for each S-W state, appear to truly drive the concomitant behaviors, e.g. a hypothetical human IF could alternate between behavioral NREMS and W/arousal/awareness; (h) a role for REMS is to keep the individual sleeping at the end of the self-limiting NREMS periods. The need for accelerating research on telencephaling NREMS periods. The need for accelerating research on telencephalic S-W processes and downstream control of the lower S-W system levels is emphasized.     

Ultrastructure of the endothelium of the drainage system of the eye

The endothelium of the ocular drainage system (Schlemm’s canal, collector tubules, and aqueous veins) in primary juvenile glaucoma undergoes degenerative dystrophic changes with compensatory hypertrophy and proliferation at the initial stages of the glaucomatous process and atrophy and desquamation at advanced and terminal stages. Progressive decrease in the pinocytous function of endotheliocytes, reduction of the protein-synthesizing and mitochondrial compartments of the cytoplasm, and formation of autophagosomes reflect the process of endotheliocyte degeneration in general. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 145, No. 5, pp. 574–577, May, 2008     

The development of the ligament of the head of the femur

The hip joints of 30 human male and female fetuses and stillborns between 20 mm and 350 mm crown-rump length were studied by light microscopy. The ligament of the head of the femur developed in situ as a condensation of mesenchyme at the end of the second month of intra-uterine life (IUL), and was vascularized by branches of acetabular vessels early in the fourth month. In the majority of fetuses older than 5.5 months IUL, vessels in the ligament passed a short way into the femoral head within cartilage canals, to supply a small region around the fovea capitis. The remainder of the head was supplied by vessels in canals from around the upper part of the neck. The ligament changed from predominantly cellular to fibrous during the last 4 months of IUL. This increase in strength suggested significant mechanical functions in utero: limitation of adduction-flexion and opposition to postero-superior dislocation were the most likely.     

Topical organization of the projections of neurons of the substantia nigra and the ventral field of the tegmentum of the midbrain to the head of the caudate nucleus of the cat

Neuroscience and Behavioral Physiology -     

电磁辐射生物效应的机理研究述评

电磁辐射好似一束带刺儿的玫瑰,她所奉献的物质文明绚丽多彩,日新月异;但人类在享用的同时,也必须提防被刺儿扎着。随着社会的发展,环境中的电磁辐射剂量（能量密度）会呈几何级数式增长。有人把电磁污染称为除空气、水、噪声污染以外的第四类污染。而且是看不见、听...