低剂量与常规剂量螺旋CT显示磨玻璃密度结节的对照研究

目的探讨低剂量及常规剂量螺旋CT扫描在检出磨玻璃密度肺结节(ground-glass nodule,GGN)的数目、边缘、内部结构与周边结构是否在统计学上存在显著差异。方法对经常规剂量(200mA)与层厚(5mm)螺旋CT扫描发现GGN患者56例同时行肺部低剂量(30mA)螺旋CT扫描,所得图像分别重建2mm、1mm,并按结节直径5mm,5~10mm,10mm不同大小分组,记录结节数目、边缘、内部特征以及周边结构等。结果低剂量与常规剂量螺旋CT扫描在检出GGN的数目、边缘、内部结构与周边结构无统计学意义。结论30mA低剂量螺旋CT扫描及层厚2mm可对GGN作出较好的判断,值得在早期肺癌筛查中应用。     

错构瘤性息肉病变的CT小肠造影表现及病理基础

目的:探讨Peut-Jeghers综合征(PJS)、Cronkhite-Canada综合征(CCS)和孤立性错构瘤性息肉的CT表现及影像病理联系。方法:回顾性分析经手术病理证实的27例胃肠错构瘤性息肉病(包括11例PJS,3例CCS和13例孤立性息肉)的MSCT表现,并与病理进行对照分析。结果:PJS和CCS息肉均为多发,累及消化道多个部位。孤立性息肉数量为1~4个,多累及结肠。息肉可有蒂或无蒂,小息肉表面多光整,密度均匀。大息肉表面不光整,呈分叶状,密度欠均匀。增强扫描息肉强化明显,出现沙砾状、点状低密度区5例,"树枝状轴心"7例,供血动脉增粗并进入息肉内5例,合并肠套叠PJS10例,孤立性错构瘤2例。PJS肠套叠的发生率高于CCS和孤立性息肉。结论:胃肠道错构瘤性息肉病的CT表现具有一定特征性,结合临床病史,有助于提高诊断准确率。     

FasL基因表达对缺氧状态下直肠癌细胞增殖凋亡的影响

Objective To elucidate the effect of FasL gene expression on the proliferation and apoptosis of hypoxic rectal carcinoma cells. Methods The normoxic expression level of FasL in HR-8348 subtype cells (HR-8348B, HR-8348L, HR-8348F and HR-8348As) with different invasive power were verified by Western blot. Hypoxia models for HR-8348B, HR-8348L, HR-8348F and HR-8348As were constructed with chemical modeling, then the FasL levels in all groups at 12 h after hypoxia were quantitated by Western blot. Distribution of different cell life cycles was determined with flow cytometry. Cell reproductive activities were detected with MTT method, and cell apoptesis was assessed with TUNEL. Results FasL protein was pigmentized at the position of 40 000 by Western blot, and the expression level of FasL was significantly higher in HR-8348F cells than those in HR-8348B, HR-8348L and HR-8348As cells(F=361.149, P<0.01) in normoxia. At 12 h after hypoxia, the FasL level was also significantly higher in HR-8348F cells than those in other groups (F=278.766, P<0.01), but was not markedly different as compared to themselves in normoxia (t=1.762, P>0.05). The proliferation index was significantly higher in HR-8348F (60.43±3.72) than those in HR-8348B (40.01±3.30), HR-8348L (41.30±4.06) and HR-8348As cells (35.87±4.39), respectively (F=39.477, P<0.01). However, both inhibition rate of proliferation and apoptotic index were remarkably lower in HR-8348F (17.30±1.98 and 13.10±1.04) than those in HR-834B (33.70±4.33 and 21.60±1.31), HR-8348L (34.20±3.92 and 20.10±1.15), and HR-8348As (38.00±4.55 and 23.90±1.23), respectively (F=28.811 and 76.462, respectively, P<0.01). Conclusion The expression enhancement of intracellular FasL in rectal carcinoma in hypoxia can lead to accelerated proliferation and reduced apeptosis of cells, which will promote tumor cells to adapt microenvironmental hypoxia.     

几丁质膜作为表皮干细胞培养支架的实验研究

Objective To investigate the feasibility of constructing a skin tissue engineering cover-ing on chitinous membrane using rat epidermal stem cells (ESCs). Methods Rat ESCs were isolated and cultured by cold digestive method and collagen type Ⅳ adherent method. Cell colonies were observed with in-verted microscope. Expressions of DNA and RNA of ESCs were detected with laser scanning confocal micro-scope. Growth curves of cells were determined with Alamar BlueTM colorimetric method. Expressions of sur-face markers of ESCs (CD29, CD71, CD49d, and CD34) were detected with flow cytometer. Positive expres-sions of CK15, CK19, and P63 of ESCs were determined by immunohistochemistry. Influence of original chi-tinous membrane leachate in different dilutions on ESCs was observed. Condition of growth of ESCs on the ve-hicle was observed. Results Isolated cultured cells were verified as ESCs, of which the doubling generation time was 48 hs. CD29 and CD49d were positive;CD71 and CD34 were negative;CKi9, CK15, and P63 were positive. Compared with that of control group, ESCs cultured in chitinous membrane leachate showed slight cell proliferation when diluted to 1:8-1:512 dilutions, but there was no statistically significant difference (P>0.05). The checkerboard-form cell colonies of ESCs could be visualized with naked eyes on the chi-tinous membrane in 2-4 weeks of culture. A multitude of ESCs were seen to grow on fibres under microscope. Conclusions Chitinous membrane may be used as ESCs culture vehicle, and biological compatibility is good.     

雅致放射毛霉蛋白酶

借助超声波、电泳和高压液相色谱技术对雅致放射毛霉胞外和胞内蛋白酶进行了研究．结果表明：腐乳前期培菌时，雅致放射毛霉同时分泌胞外及胞内蛋白酶，两者酶活力变化趋势基本相同，在培菌45h时，达到最大酶活力；胞外和胞内蛋白酶均为蛋白酶系，相对分子质量组成相同；以大豆蛋白为底物时，主要水解产物相同．     

不同真空预冷终温对双孢蘑菇保鲜的影响

真空预冷技术应用于双孢蘑菇的预处理，研究了双孢蘑菇在不同预冷终温过程中的温度、压力及品质的变化，并在随后的贮藏过程中，以呼吸强度、失重率和VC含量、细胞膜透性和感官品质为考察指标，从而确定最佳的预冷温度为5℃。经真空预冷处理的蘑菇的生理生化指标和感官品质均优于对照样．     

合并体位性低血压对维持性血液透析患者预后的影响

目的评估体位性低血压（OH）对维持性血液透析患者预后的指示意义。方法分析评估2004—2007年62例维持性血液透析患者OH与其他因素导致患者死亡的关系。参试患者进入试验时一般状态稳定,每次血液透析治疗前连续进行5次血压测定。OH定义：从卧位变为立位后肱动脉收缩压下降大于20mmHg（1mmHg=0．133kPa）或舒张压下降大于10mmHg。结果62例患者中,35．5％（22／62）存在不同程度的OH。在平均（35．0±47．6）周（1～140周）的随访期间,共记录到7例患者死亡。使用多变量COX比例危险率回归模型分析表明患者年龄、存在OH和既往有脑血管基础疾病史是患者远期预后（死亡）的独立预测因素。同时,使用Kaplan—Meier生存分析法判断所有参试患者存在和不存在OH的远期预后,发现差异均有统计学意义。结论血液透析患者开始出现OH是标志患者远期预后（各种原因导致死亡）的独立指示因素。     

Estudio ultrasonográfico e histológico de la evolución de un modelo canino de hiperplasia benigna de próstata inducida por hormonas

IntroductionDespite exhibiting histological differences from the human process, canine hormone-induced benign prostatic hyperplasia (BPH) is still the most widely used animal model for evaluating treatment strategies.ObjectivesThe aim of this study is to determine the optimal moment for starting a therapeutic trial in this animal model.Material and methodsSix male beagle dogs over one year of age were used in this study. All animals received a combination of steroid hormones, namely 17β-estradiol and 5α-androstene 3α 17β-diol, every other day during three (Group 1, n=3) or five months (Group 2, n=3). Transrectal ultrasonographic examinations to measure prostate volume were performed monthly. Animals were euthanized after five months for histological study of their prostates.ResultsAll animals developed BPH, with prostate volume increasing over time as hormones were administered (r=0,910). All ultrasonographic studies performed up to the third month evidenced a significant increase in prostate volume when compared to the prior ultrasound measurement. A significant decrease in prostate volume was seen in Group 1 once hormone administration was interrupted, whereas Group 2 animals showed a continuing increase in prostate size. Histological examination showed almost no evidence of BPH in Group 1 animals, while Group 2 animals clearly exhibited moderate epithelial hyperplasia.ConclusionsThe administration of a combination of steroid hormones is effective in inducing benign prostatic hyperplasia in canines, but this hyperplasia disappears when hormone treatment is interrupted. In order to be useful for experimental studies, hormones should be administered for at least three months before commencing any treatment, and they should be continued throughout the length of the study..     

Chitooligosaccharides promote peripheral nerve regeneration in a rabbit common peroneal nerve crush injury model

Chitooligosaccharides (COSs) are the biodegradation products of chitosan that have been demonstrated with neuroaffinity and/or neuroprotective actions. In this study, we investigated the possible benefits of treatment with COSs on nerve regeneration after crush injuries to peripheral nerves. The rabbits with the crushed common peroneal nerve were treated by daily intravenous injection of 1.5 or 3 mg/kg body weight of COSs or identical volume of saline (as the control) for a 6‐week period. At the end of COSs treatment, electrophysiological assessments, Meyer's trichrome and Masson trichrome staining, and transmission electron microscopy were used to evaluate the regeneration of injured common peroneal nerve and atrophy of the tibialis posterior muscle. The results showed that the compound muscle action potentials, the number of regenerated myelinated nerve fibers, the thickness of regenerated myelin sheaths, and the cross‐sectional area of tibialis posterior muscle fibers were significantly improved in the nerves that received COSs treatment and the results with COSs treatment displayed a dose‐dependent pattern. This study demonstrated that COSs accelerated peripheral nerve regeneration after crush injury to rabbit common peroneal nerves. The COSs could probably become a potential neuroprotective agent for improvement of peripheral nerve regeneration after the injury and deserve for further studies. © 2009 Wiley‐Liss, Inc. Microsurgery, 2009.     

磁性阿霉素隐形脂质体对裸鼠移植性人胃癌的靶向治疗

目的　探讨磁性阿霉素隐形脂质体靶向治疗裸鼠移植性人胃癌的疗效。方法　荷人胃癌的裸鼠为动物模型,尾静脉给药,肿瘤部位放置恒定磁场进行磁导向化疗。结果　磁性阿霉素隐形脂质体靶向MDL( )组对人胃癌的移植瘤有显著抑制作用,体积和瘤重抑瘤率分别为71%和70 % ,显著高于磁性阿霉素隐形脂质体非靶向MDL(- )组(5 7%、5 0 % )和游离阿霉素DOX组(33%、31% )(P <0 .0 5 ) ,空白组细胞凋亡率均低于各实验组,MDL( )组达4 2 % ,高于其他各组(P <0 . 0 5 )。实验期间DOX组体重一直未见增加,而MDL( )组体重平稳增加,且饮食、活动未见明显变化。结论　磁性阿霉素隐形脂质体作为一种新型抗肿瘤药物显示了良好的应用前景。