视频显示终端脉冲磁场对细胞间隙连接通讯功能的影响研究

目的：研究视频显示终端（ＶＤＴ）脉冲磁场对细胞间隙连接通讯功能的影响。方法：用１５．６ｋＨｚ、峰值强度为２００ μＴ的脉冲磁场（ＰＭＦ）和（或）十四酰基咐拜醇酯（ＴＰＡ：５ ｎｇ／ｍ ｌ）对培养的中国仓鼠肺成纤维细胞（ＣＨＬ）进行辐射２４ ｈ,采用离子电渗注射法观察荧光黄向与其接触的周围细胞的传递情况。结果：ＴＰＡ对细胞间隙连接通讯（ＧＪＩＣ）功能具有抑制作用,与空白对照组相比有显著差异（Ｐ＜ ０．０１）,单纯ＶＤＴ组对ＧＪＩＣ无抑制作用（Ｐ＞ ０．０５）,亦未见该脉冲磁场对ＴＰＡ的抑制作用有增强效应。结论：视频显示终端脉冲磁场（１５．６ ｋＨｚ）对细胞间隙连接通讯功能无直接和（或）协同ＴＰＡ的抑制作用     

脑动静脉畸形影像学诊断方法的评价

目的评价数字减影血管造影（ＤＳＡ）、磁共振成像（ＭＲＩ）及磁共振血管造影（ＭＲＡ）在脑动静脉畸形（ＡＶＭ）诊断中的价值。②方法对病理证实的１１３例ＡＶＭ病人皆行ＤＳＡ及ＭＲＩ检查,其中６７例行ＭＲＡ检查。③结果ＤＳＡ表现为密集成球、相互交叉缠绕的血管团或块状血管;ＭＲＩ表现为蜂窝状、葡萄状和条索状流空血管,无明显占位效应;ＭＲＡ显示局部纡曲的血管团,血管分支增多,缠绕在一起。ＤＳＡ及ＭＲＩ对ＡＶＭ的诊断率远高于ＭＲＡ（χ２＝１０６．７,Ｐ＜０．０１）。④结论ＤＳＡ与ＭＲＩ结合使用,对ＡＶＭ的诊断及治疗有重要价值。ＭＲＡ可作为ＭＲＩ的补充用于筛选及ＡＶＭ切除术后随访检查。     

View box luminance measurements and their effect on reader performance

RATIONALE AND OBJECTIVES: The purpose of this study was to investigate the importance of view box luminance and viewing conditions on low-contrast detection by readers. MATERIALS AND METHODS: Radiographs of a mammographic contrast-detail phantom were examined on 632 view box panels. The luminance of these panels was obtained by using a calibrated meter and ranged from 860 to 3,300 nit. Twelve radiologists reported the number of contrast-detail disks for each size (diameter, 0.3-7.0 mm) deemed to be visible on films with optical densities of 1.00-2.60. Radiologist performance in reading low-contrast phantom images was also studied as a function of room illuminance and image masking. RESULTS: Median luminance was 1,700 nit, with 25- and 75-percentile values of 1,450 and 2,150 nit, respectively. Low-contrast visibility generally was independent of view box luminance, regardless of film density or disk diameter. Low-contrast visibility deteriorated when masking around the image was removed and at normal room illuminance. The greatest deterioration in performance occurred at the highest film densities and with the smallest size disks. CONCLUSION: Detection of low-contrast features on radiographs is relatively independent of view box luminance, but it is degraded by the presence of stray light and by increased room illuminance.     

环孢素对心脏移植大鼠外周血淋巴细胞多基因mRNA表达的影响

 目的 对大鼠心脏移植前后不同时间点外周血淋巴细胞mRNA差异表达的研究,探讨环孢素对免疫排斥反应过程中基因表达的影响.方法 心脏移植前后以15 mg·kg^-1·d^-1环孢素灌胃的大鼠,分别在移植前、移植后24,72 h,7,10,12d取血,提取总RNA,用mRNA差异显示法找出差异表达条带,克隆测序,用灰度扫描法计算差异表达基因的比密度。结果 对照组移植心脏存活率于移植后的10d内降至为0%,而此阶段环孢素组的移植心脏存活率始终保持在50％.移植后第10天,对照组与凋亡信号传导和线粒体蛋白构象重构与蛋白转运相关基因Ribosomal—12S和S25,MHC—Ⅲ(Hst-70)的表达水平显著高于移植前,与移植心脏存活率最低点同步.其2,3-bisphosphoglycerate和gig18基因表达水平的变化无统计学意义。环孢素组与细胞凋亡有关的gig18和Thbsl,以及T细胞受体(TCR)等基因的表达水平于移植后10 d内持续低于移植前,2,3-bisphosphoglycerate基因的表达水平于移植后24 h降低,只有钠通道β-1基因的表达水平于移植后10 d内高于移植前。结论 环孢素可负调心脏移植后大鼠外周血淋巴细胞凋亡相关基因gig18和Thbsl,正调钠通道基因的转录。     

基于Hilbert曲线的数字图像置乱方法研究

研究了基于Hilbert曲线的数字图像置乱方法 ,引入二个概念 :“重合度”和“Hilbert曲线的平移” ,利用Hilbert曲线平移 ,获得了更多新的置乱路径 ,并根据重合度变化图探讨了置乱变换的规律 ,以测试置乱变换的周期和拟周期。然后把基于Hilbert曲线的置乱方法推广到任意大小的图像。实验结果表明 :利用Hilbert路径进行置乱不仅具有非常大的置乱路径选择空间 ,而且具有很好的置乱效果和极大的置乱周期 ,具有较大的实用性。     

术前IADSA和栓塞术在鼻咽纤维血管瘤治疗中的应用

目的：研究分析术前经动脉数字减影血管造影（ＩＡＤＳＡ）和栓塞术在鼻咽纤维血管瘤治疗中的价值。方法：分析本院２１例鼻咽纤维血管瘤患者的临床分析治疗资料，１主后１年复发，再次手术治疗。２２次手术中，术前行及未行ＩＡＤＳＡ和栓塞术的各１１次。 术前示行和行ＩＡＤＳＡ和栓塞术的要中平均出血量和输血量。结果：术前未行和行ＩＡＤＳＡ和栓塞术的术中出量量和输血量分别为１１３６ｍｌ、８３６ｍｌ、６７７ｍｌ、４００     

Evaluation of the effectiveness of preoperative embolization in surgery for nasopharyngeal angiofibroma

We retrospectively analyzed the clinical data of 21 patients (22 procedures) with histologically proven nasopharyngeal angiofibromas. Eleven patients underwent preoperative intra-arterial digital subtraction angiography (IADSA) and embolization with Gelfoam. Embolization reduced the intraoperative blood loss from an average of 1136 ml in the non-embolized patients to 677 ml in the embolized cases (P < 0.05) and transfusions from an average of 836 ml to 400 ml (P < 0.01). Results again show that preoperative embolization is effective in reducing intraoperative blood loss. Received: 10 May 1997 / Accepted: 21 October 1997     

抗前列腺癌细胞特异抗体库的构建及特异结合抗体的筛选

目的: 获得前列腺癌的噬菌体呈现型单链抗体库,筛选与前列腺癌特异结合的抗体,为前列腺癌的诊断和治疗奠定基础. 方法: 用两种恶性程度较高的前列腺癌细胞PC3,DU145膜蛋白混合物免疫Balb/c小鼠.取脾脏提取总RNA,用RT-PCR分别扩增抗体重、轻链可变区基因(VH和VL), 经Linker连接形成ScFv基因片段,将ScFv基因片段与噬菌粒载体pCANTAB 5E的连接产物转化大肠杆菌TG1.用辅助噬菌体M13KO7进行超感染,获得重组噬菌体抗体.以恶性程度低的前列腺癌细胞LNCap为对照,用PC3细胞对重组噬菌体抗体库进行五轮筛选后,随机挑取克隆,经phage-ELISA筛选特异性结合PC3细胞的ScFv.结果: 用所构建的库容量为3.5×106的单链抗体库筛选特异结合抗体,得到一个与PC3细胞特异结合的噬菌体-单链抗体.结论: 本研究所构建的抗体库中可筛选到与前列腺癌细胞结合特异性较好的抗体,可用于前列腺癌的诊断和治疗中.     

基于DSP的人工电子耳语音信号处理的研究

介绍人工电子耳的基本原理和ClS语音信号处理方案,提出基于DSP芯片TMS320LF2407的硬件电路设计和软件编程流程,最后通过计算机对经过DSP处理后的语音数据进行了仿真和合成,实验结果表明合成语音与原始语音在频谱包络特征上非常相似.     

Quantitative computer‐assisted digital‐imaging upper airway analysis for obstructive sleep apnoea*

This was a prospective study of a new objective method which quantitatively analyses the upper airways in patients with obstructive sleep apnoea (OSA). Video‐nasopharyngoscopic examinations of the upper airways of 45 patients were carried out with an endoscopic calibrator. Images of the upper airway during quiet respiration and Mueller's manoeuvre in erect and supine positions were digitized by computer to generate the actual dimensions of obstructive sites. Measurements by the new method were validated by comparing 90 pairs of videoendoscopic images with upper airway magnetic resonance imaging (MRI) measurements at two identical levels. Quantitative precision is 100% for the retropalatal level and 95.6% for the retrolingual level with a tolerance of 0.5 cm² between the two methods. The absolute mean of the difference between the two methods of measurement is 0.08 cm² at the retropalatal level and 0.18 cm² at the retrolingual level. The agreement between the digital‐imaging videoendoscopic and MRI measurements was 93.3% for the retropalatal level and 95.6% for the retrolingual level. Quantitative computer‐assisted digital imaging is a reliable, cost‐effective clinical method of upper airway evaluation in OSA patients. This method allows us to examine the dynamic and static morphology objectively, measure surgical outcomes of upper airway, opening up new avenues for OSA management.