髓样细胞白血病-1基因在多发性骨髓瘤发病中的分子机制

目的通过检测骨髓瘤细胞中依赖IL-6与否的髓样细胞白血病-1(mcl-1)基因的表达,阐明mcl-1基因在多发性骨髓瘤发病中的信号转导通路。方法应用JAK特异性抑制剂AG490、蛋白激酶抑制剂LY294002、ERK1/2信号通路的特异性阻断剂PD98059,分别研究了JAK/STAT通路、ras/MAPK通路及PI3K/Akt三大信号途径与mcl-1基因在多发性骨髓瘤中的关系。结果在骨髓瘤细胞8226和U266中,抑制ERK1/2活性不能改变mcl-1的表达;高浓度的AG490不能抑制STAT3的酪氨酸磷酸化;LY294002可抑制8226细胞和ANBL-6细胞的增殖,但不抑制mcl-1的表达。结论 Ras/MAPK通路以及PI3K通路在mcl-1基因的调节中无作用,但STAT的作用仍然需要进一步探讨。     

siRNA沉默MAPK p42对肝癌SMMC7721增殖和凋亡的影响

目的应用siRNA沉默SMMC7721细胞MAPK p42,并观察其对增殖和凋亡的影响。方法应用SilencerTMsiRNA构建试剂盒合成2条MAPK p42siRNAs和一条随机对照siRNAs,用脂质体LipofectaminTM 2000将其转染入肝癌SMMC-7721细胞株。应用Western blot检测MAPK p42表达,MTT法检测细胞增殖情况,流式细胞仪分析细胞周期及其细胞凋亡。结果与对照相比,MAPK p42siRNA明显抑制MAPK p42表达。MAPK p42siRNA抑制了SMMC-7721细胞的生长,将细胞阻滞于细胞周期S期,进而诱导了细胞凋亡的发生。结论 MAPK p42靶向siRNA可能为肝癌基因治疗的重要手段。     

清热益气通络方治疗糖尿病肾病大鼠蛋白尿的实验研究

目的探讨清热益气通络方治疗糖尿病肾病(DN)大鼠蛋白尿的机制。方法 37只采用单侧肾切除腹腔注射链脲佐菌素的方法建立的糖尿病肾病大鼠模型分为3组:模型组、中药组和厄贝沙坦组,另设正常对照组。连续治疗12周后,检测24h微量白蛋白(umAlb)、24h尿蛋白量(UPro)、内生肌酐清除率(Ccr)。免疫荧光双标记足细胞表面特异性蛋白(podocalyxin)、结蛋白(desmin),荧光标记足细胞肾胚胎瘤抑制基因(wilms tumor 1,WT1)计数足细胞数及密度。光镜及电镜观察肾小球结构。结果与对照组比,模型组大鼠BW/KW、24hUPro、24humAlb、Ccr及desmin吸光度显著增高(P<0.01或P<0.05),podocalyxin吸光度及足细胞密度显著降低(P<0.01);清热益气通络方及厄贝沙坦能改善DN大鼠以上指标,与模型组比有统计学差异(P<0.01或P<0.05);清热益气通络方降低24hUPro及上调podocalyxin表达的作用优于厄贝沙坦(P<0.05)。结论清热益气通络方药能降低DN尿蛋白的排泄,其作用机制可能与拮抗podocalyxin、desmin蛋白在足细胞的异常表达、一定程度抑制DN足细胞上皮-间充质转分化有关。     

多媒体数据压缩技术及其实现

根据上海站多媒体信息网与信息中心的实际需求，重点介绍了静态图象压缩标准ＪＰＥＧ的基本原理，分析并给出了采用硬件的软件方式实现该标准的多种途径。     

体表心电图的细胞电生理和分子遗传学基础(一)

经体表描记的心电图是大量心肌细胞在时间和空间有序的电活动的综合电图。心肌兴奋过程中，各种离子通道相继开放和关闭，引起跨膜细胞离子流的变化。心肌细胞产生动作电位是心脏生物电的基础，也是理解和解释体表心电图的理论依据。心肌细胞动作电位产生和传导过程中，心肌及其周围组织产生一个心电场，而心脏及其周围组织为容积导电体，心电场经过该容积导体向外传播至体表探测记录电极的不同部位，再经心电图机的滤波、放大而产生一幅完整的心电图。因此，心肌细胞电生理是临床心电图的基础。     

基于区域增长及边缘检测的一种图象分割方法

提出一种图象分割算法，这种算法综合了三种算法，即区域增长、边缘检测及保持边平滑平衡，它可以明显地克服区域增长及边缘检测各自的缺点，在这种方法中还引进了边界平滑算法使得分割所产生的边界更可靠，可直接应用到三图象分割，医学图象分割的实验中，证明了这种方法的有效性。     

多抗乙素可增强特异性细胞毒T细胞活性──在体动物实验

利用Ｃ５７ＢＬ／６纯系小鼠，皮下接种Ｓ１８０肉瘤细胞建立肿瘤模型，并用多抗乙素进行治疗，结果显示，治疗组肿瘤体积明显小于对照组（０．６６ｃｍ３／１．４８ｃｍ３Ｐ＜０．０５）。以脾细胞为效应细胞，Ｓ１８０肉瘤细胞为靶细胞，检测细胞毒活性，发现治疗组有较高的特异性细胞毒活性（１８０，３１１溶解单位／１３８溶解单位Ｐ＜０．０１）。结合以往的体内外实验结果，推测多抗乙素能够增强特异性细胞毒性Ｔ细胞活性。     

Joint distortion model for progressive image transmission using error correcting arithmetic codes

A novel joint source channel distortion model was proposed, which can essentially estimate the average distortion in progressive image transmission. To improve the precision of the model, the redundancy generated by a forbidden symbol in the arithmetic codes is used to distinguish the quantization distortion and the channel distortion, all the coefficients from the first error one to the end of the sequence are set to be a value within the variance range of the coefficients instead of zero, then the error propagation coming from the entropy coding can be essentially estimated, which is disregarded in the most conventional joint source channel coding （JSCC） systems. The precision of the model in terms of average peak-signal-to-noise has been improved about 0.5 dB compared to classical works. An efficient unequal error protection system based on the model is developed, and can be used in the wireless communication systems.     

A bintree energy approach for colour image segmentation using adaptive channel selection

A new hierarchical approach called bintree energy segmentation was presented for color image segmentation. The image features are extracted by adaptive clustering on multi-channel data at each level and used as the criteria to dynamically select the best chromatic channel, where the segmentation is carried out. In this approach, an extended direct energy computation method based on the Chan-Vese model was proposed to segment the selected channel, and the segmentation outputs are then fused with other channels into new images, from which a new channel with better features is selected for the second round segmentation. This procedure is repeated until the preset condition is met. Finally, a binary segmentation tree is formed, in which each leaf represents a class of objects with a distinctive color. To facilitate the data organization, image background is employed in segmentation and channels fusion. The bintree energy segmentation exploits color information involved in all channels data and tries to optimize the global segmentation result by choosing the ＂best＂ channel for segmentation at each level. The experiments show that the method is effective in speed, accuracy and flexibility.