氧化修饰的低密度脂蛋白和极低密度脂蛋白对单核细胞MCP—1…

为了研究氧化修饰的低密度脂蛋白（ＯＸ－ＬＤＬ）和氧化修饰的极低密度脂蛋白（ＯＸ－ＶＬＤＬ）对单核细胞的单核细胞趋化蛋白１（ＭＣＰ－１）ｍＲＮＡ和蛋白表达的影响，在单核细胞的培养基中分别加入２５μｇ／ｍｌ的ＬＤＬ，ＯＸ－ＬＤＬ，ＶＬＤＬ和ＯＸ－ＶＬＤＬ，培养２４小时后分别收集单核细胞及其条件培养基，对照异硫氰酸胍法提取单核细胞总ＲＮＡ，并用γ＾３２Ｐ末端标记ＭＣＰ－１寡核苷酸探针，进行ｓｌｏｔｂｌｏ     

正常人外周血和胸腺T细胞中TCR DδX基因重排的特点

目的：分析正常人外周血和胸腺细胞中 ＴＣＲ ＤδＸ基因重排分布特点。方法：利用半巢式 ＰＣＲ扩增 １０例正常人外周血单个核细胞（ＰＢＭＣｓ）、４例分选的外周血 ＣＤ３＋Ｔ细胞和 ７例正常人胸腺细胞 ＤＮＡ的 ＴＣＲ ＤδＸ基因与ＪδＸ、Ｄδ３和　Ｊａ重排的情况，从不同含量 ＤＮＡ的 ＰＣＲ分析，了解其重排分布频率。结果：ＴＣＲ ＤδＸ分别与 ＪδＸ、Ｄδ３和　Ｊａ的重排均可见于多数外周血Ｔ细胞和胸腺细胞中，对不同含量的ＤＮＡ的ＰＣＲ分析显示ＴＣＲ ＤδＸ重排的分布频率在外周血和胸腺细胞有所不同。结论：ＴＣＲ ＤδＸ－　Ｊａ的重排最常见于成熟和未成熟Ｔ细胞中，而ＴＣＲ　ＤδＸ－Ｄδ３则在未成熟Ｔ细胞中多见。     

宽谱双能X线数字减影技术

数字减影（ＤＳＡ）中的一种新颖的医学成像方法－－双能（ｄｕａｌ ｅｎｅｒｇｙ）Ｘ线数字减影技术，正在被广泛地研究。这种新的成像方法是利用人体中不同组织对Ｘ线的不同吸收率来实现的。本文在对大量的文献资料进行综合的基础上，对双能减影的研究进行了较为全面的综述，对具有代表性的方法在其研究思想、技术方法和结论方面作了详细的介绍。并对这些方法给予评价，作了综合的讨论。     

氧化修饰和乙酰修饰低密度脂蛋白在A型清道夫受体基因敲除小鼠的清除

目的：阐明清道夫ＡＩ／Ｉ受体（ＳＲ－ＡＩ／Ｉ）在体内ＯＸ－ＬＤＬ和ＡＣ－ＬＤＬ清除中的作用和重要性。方法：观察同位素标记化学修饰ＬＤＬ在ＳＲ－ＡＩ／Ｉ基因敲除和正常小鼠血浆的清除率和同位素标记的ＬＤＬ在体内主要器官的分布。结果：ＯＸ－ＬＤＬ在正常小鼠血浆清除是非常快的,在５ｍｉｎ内,注入量的９０％即被清除。在ＳＲ－ＡＩ／Ｉ基因敲除小鼠,ＯＸ－ＬＤＬ在血浆的清除速率和正常小鼠相同。ＡＣ－ＬＤＬ的清除在对照组和ＳＲ－ＡＩ／Ｉ受体敲除小鼠也相似。同位素标记的ＡＣ－ＬＤＬ在血浆的清除能够完全被５０倍高剂量未标记的ＡＣ－ＬＤＬ阻断,但同样剂量的未标记的ＡＣ－ＬＤＬ仅能抑制ＯＸ－ＬＤＬ在血浆清除的５％。ＯＸ－ＬＤＬ和ＡＣ－ＬＤＬ主要被肝脏清除。组织器官放射性标记的ＯＸ－ＬＤＬ和ＡＣ－ＬＤＬ的分布在正常小鼠和ＳＲ－ＡＩ／Ｉ基因敲除小鼠没有差异。结论：ＳＲ－ＡＩ／Ｉ受体在体内ＯＸ－ＬＤＬ清除过程中不起主要作用。     

血栓素A2,肿瘤坏死因子和地塞米松对兔气道平滑肌细胞增？…

目的；探讨血栓素Ａ２（ＴＸＡ２）、肿瘤坏死因子（ＴＮＦ－α），地塞米松（Ｄｅｘ）对气管平滑肌细胞（ＡＳＭＣ）增生的影响。结论：ＴＸＡ２、ＴＮＦ－α在ＡＳＭＣ增生中起重要作用，Ｄｅｘ在治疗哮喘过程中，有可能加重ＡＳＭＣ的增生。     

树突状细胞与趋化因子的研究进展

趋化因子可分为４个亚家族，其中Ｃ－Ｃ家族的成员最多，不同家族的趋化因子具有不同的结构及功能特点，趋化因子受体属于Ｇ蛋白偶联受体超家族，是一含有７个疏水性穿膜区段的单链受体，大多数趋化因子受体能结合同一个亚家族中多个成员，ＤＣ表达高水平ＣＣＲ１，ＣＣＲ２和ＣＣＲ５，以及ＣＸＣＲ１，ＣＸＣＲ２和ＣＸＣＲ４，这些受体通过结合相应的趋化因子诱导ＤＣ的趋化反应，在ＤＣ的迁移过程中起重要作用，ＤＣ表达的趋化因     

数字X线成像术探测器

数字化Ｘ射线成像技术提高了图像质量，使其能够进行医学图像处理、计算机辅助诊断及远程放射成像。图象质量与从病人身上透射过来的Ｘ线信息的准确探测紧密相关，即与Ｘ线探测器的性能关系密切。数字放射成像术的探测器必须适合它们被应用的特殊的放射学过程。主要的参数有：空间分辨率、响应均匀性、对比灵敏度、动态范围、探测速度。下面将对一些适合数字Ｘ射线成像的探测器技术进行回顾，探讨用于全方位探测器的设备及适于Ｘ线扫     

氧化修饰极低密度脂蛋白对单核和巨噬细胞趋化蛋白1mRNA表…

近年来的研究发现，单核细胞趋化蛋白１（ＭＣＰ－１）是一种极为强烈的单核细胞趋向因子。本研究着重观察了极低密度脂蛋白（ＶＬＤＬ）和氧化修饰的极低密度脂蛋白（ＯＸ－ＶＬＤＬ）对单核细胞和巨噬ＭＣＰ－１ｍＲＮＡ表达的影响。在单核核和巨噬细胞的培养基中分别中入２５μｇ／ｍｌ的ＶＬＤＬ或ＯＸ－ＶＬＤＬ，培养２４ｈ提取单核细胞和巨噬细胞总ＲＮＡ用ＭＣＰ－１的寡核苷酸探针，进行Ｎｏｒｔｈｅｍｂｌｏｔ分析。结果显     

趋化因子研究进展—趋化因子家族（一）

除经典趋化剂Ｃ５ａ，ｆＭＬＰ、白三磷Ｂ４，ＰＡＦ外，新发现并鉴定了一族趋化因子，目前至少有１９种，根据其结构和功能特点为Ｃ－Ｘ－Ｃ矣Ｃ－Ｃ两个亚族，Ｃ－Ｘ－Ｃ亚族主要趋化和激活中性粒细胞，Ｃ－Ｄ亚族主要趋化和激活性单核细胞。     

数字X线成像术探测器

数字化Ｘ射线成像技术提高了图象质量，使其能够进行医学图像处理、计算机辅助诊断及远程放射成像。图象质量与从病人身上透射过来的Ｘ线信息的准确探测紧密相关，即与Ｘ线探测器的性能关系密切。数字放射成像术的探测器必须适合它们被应用的特殊的放射学过程。主要的参数有：空间分辨率、响应均匀性、对比灵敏度、动态范围、探测速度。下面将对一些适合数字Ｘ射线成像的探测器技术进行回顾，探讨用于全方位探测器的设备及适于Ｘ线扫描系统的设备。     

A time-delay integration charge-coupled device camera for slot-scanned digital radiography

We have developed a low-noise digital camera based on a 512 x 96 element CCD operating in the time-delay integration mode. This camera has been combined with an x-ray image intensifier to record radiographic images produced by a scanning slot beam of radiation. This results in the rejection of a large fraction of scattered radiation, without a significant increase in x-ray tube heat loading or image acquisition time. Here we describe the design of our CCD camera and the results of our investigations of camera resolution, linearity, noise, and quantum efficiency. We have found that both the resolution limit (50 mm-1) and the dynamic range (2100) of this novel camera are greater than reported values for conventional video cameras. Applications of this system in digital angiography and mammography are discussed.     

射波刀VSI系统非晶硅平板数字探测器的影像质量研究

目的:基于QCkV-1模体结合PIPSpro软件评估分析射波刀VSI系统非晶硅平板数字探测器记录的影像质量。方法:将QCkV-1模体配合专用定位架按照预先制定的计划重复放置于射波刀成像子系统的影像中心位置,X射线管拍片后获取由非晶硅平板数字探测器(成像仪A和B)记录的两组影像,导入PIPSpro软件分析,指标包括空间分辨率(f30、f40、f50)和对比度噪声比。结果:在临床治疗的kV值范围内(100~125 kV),成像仪A的f30、f40、f50最大偏差为0.94%、1.67%、0.29%,成像仪B分别为0.81%、1.31%和1.42%。对于对比度噪声比,当小于115 kV时两成像仪随kV值变化平缓,大于115 kV时展现出明显分化。结论:QCkV-1模体结合PIPSpro软件能够便捷开展射波刀VSI系统非晶硅平板数字探测器成像质量的检测分析工作。     

Present and prospects of telepathology

Nearly ten years have passed since telepathology was introduced and real-time pathology consultations were conducted. Long distance consultations in pathology, cytology, computed tomography and magnetic resonance imaging, which are referred to as telemedicine, clearly enhance the level of medical care in remote hospitals where no full-time specialists are employed. To transmit intraoperative frozen section images, we developed a unique hybrid system "Hi-SPEED". The imaging view through the CCD camera is controlled by a camera controller that provides NTSC composite video output for low resolution motion pictures and high resolution digital output for final interpretation on computer display. The results of intraoperative frozen section diagnosis between the Gihoku General Hospital 410 km from SRL showed a sensitivity of 97.6% for 82 cases of breast carcinoma and a false positive rate of 1.2%. This system can be used for second opinions as well as for consultations between cytologists and cytotechnologists.     

基于TDICCD的动态成像实验

目的延迟积分型电荷耦合器件（time delay integration and charge coupled device,TDI CCD）灵敏度高,并在低照度下具有获得高质量图像的特点,已成为齿科全景数字化成像系统开发的关键技术。在成像过程中要想得到清晰图像,必须正确使用TDI CCD。方法本文采用FCFR-USB9825B系列采集卡等搭建的动态成像装置进行实验,通过改变TDI CCD积分方向和积分时间,采集到不同图像。结果通过对比图像,发现在TDI CCD使用过程中,TDI CCD的积分方向必须与成像物体移动方向保持一致。TDI CCD积分时间与物体移动速度必须匹配,即二者的乘积等于像元尺寸。结论本实验为基于TDI CCD的全景齿科成像奠定了成像理论基础。     

Evaluation of and compensation for spatial noise of LCDs in medical applications

Recent developments in liquid crystal display (LCD) technology suggest that this technology will replace the cathode ray tube (CRT) as the most popular softcopy display technology in the medical arena. However, LCDs are far from ideal for medical imaging. One of the principal problems they possess is spatial noise contamination, which requires accurate characterization and appropriate compensation before LCD images can be effectively utilized for reliable diagnosis. This paper presents some work we have conducted recently on characterization of spatial noise of high resolution LCDs. The primary purpose of this work is to explore the properties of spatial noise and propose a method to reduce it. A high quality CCD camera was used for physical evaluation. Spatial noise properties were analyzed and estimated from the camera images via signal modeling and processing. A noise compensation algorithm based on error diffusion was developed to process images before they were displayed. Results shown in this paper suggest that LCD spatial noise can be effectively reduced via appropriate processing.     

Localization error analysis for stereo X-ray image guidance with probability method.

The mean value and standard deviation of localization error for the stereo imaging systems are derived based on probability theory. Compared with the maximum error analysis method used in our previous study, the new approach yields more informative and precise results as the guidance for X-ray imaging system design and protocol optimization. The prototype for our current study is a CCD based monoplane digital stereo X-ray imaging system. The imaging model consists of two X-ray sources and one detector plane. With perspective geometry, the least-square solution is derived to reconstruct 3-dimensional object points, such as a biopsy needle tip, from a pair of 2-dimensional digital radiographs. Under the conditions of our specific prototype, the measurement errors of interested points in the radiographs are modeled as random variables with Gaussian distribution. Such variables account for finite image system noise and positioning errors. Then, the 3D localization error, in terms of mean value and standard deviation, is formulated using measurement error, feature point location, and separation between the two X-ray sources and distance from source to detector. Both theoretical analysis and numerical simulation are performed. The mean value and standard deviation of the localization error are first evaluated using numerical simulation under practical imaging conditions. Then, the error estimates are given in simply analytic forms. Simulation and theoretical results are in excellent agreement. The results show that our prototype X-ray stereological imaging system is accurate and reliable to locate feature points in 3D for medical intervention. Imaging protocols can be effectively optimized through the 3D localization error analysis using the approximate formulas proposed in this study.     

Localization capability and limitation of electron-multiplying charge-coupled, scientific complementary metal-oxide semiconductor, and charge-coupled devices for superresolution imaging

Localization of a single fluorescent molecule is required in a number of superresolution imaging techniques for visualizing biological structures at cellular and subcellular levels. The localization capability and limitation of low-light detectors are critical for such a purpose. We present an updated evaluation on the performance of three typical low-light detectors, including a popular electron-multiplying CCD (EMCCD), a newly developed scientific CMOS (sCMOS), and a representative cooled CCD, for superresolution imaging. We find that under some experimental accessible conditions, the sCMOS camera shows a competitive and even better performance than the EMCCD camera, which has long been considered the detector of choice in the field of superresolution imaging.     

Colorized Digital Transmission Electron Microscopic Images for Teaching Pathology

We describe how electron microscopic images can be selectively colorized to accentuate ultrastructural detail for teaching purposes. Images are either captured by a CCD camera attached to the electron microscope or are scanned into a computer as electron micrographs. The computer's digital images are then manipulated using image-editing and colorizing software to highlight specific ultrastructural details, and subsequently printed or converted into 35-mm slides to be used for teaching.     

Comparison of entrance exposure and signal-to-noise ratio between an SBDX prototype and a wide-beam cardiac angiographic system

The scanning-beam digital x-ray (SBDX) system uses an inverse geometry, narrow x-ray beam, and a 2-mm thick CdTe detector to improve the dose efficiency of the coronary angiographic procedure. Entrance exposure and large-area iodine signal-to-noise ratio (SNR) were measured with the SBDX prototype and compared to that of a clinical cardiac interventional system with image intensifier (II) and charge coupled device (CCD) camera (Philips H5000, MRC-200 x-ray tube, 72 kWp max). Phantoms were 18.6-35.0 cm acrylic with an iohexol-equivalent disk placed at midthickness (35 mg/cm2 iodine radiographic density). Imaging was performed at 15 frame/s, with the disk at mechanical isocenter and an 11-cm object-plane field width. The II/CCD system was operated in cine mode with automatic exposure control. With the SBDX prototype at maximum x-ray output (120 kVp, 24.3 kWp), the SBDX SNR was 107%-69% of the II/CCD SNR, depending on phantom thickness, and the SBDX entrance exposure rate was 10.7-9.3 R/min (9.4-8.2 cGy/min air kerma). For phantoms where an equal-kVp imaging comparison was possible (> or = 23.3 cm), the SBDX SNR ranged from 47% to 69% of the II/CCD SNR while delivering 6% to 9% of the II/CCD entrance exposure rate. From these measurements it was determined that the relative SBDX entrance exposure at equal SNR would be 31%-16%. Results were consistent with a model for relative entrance exposure at equal SNR, which predicted a 3-7 times reduction in entrance exposure due to SBDX's comparatively low scatter fraction (5.5%-8.1% measured, including off-focus radiation), high detector detective quantum efficiency (66%-73%, measured from 70 to 120 kVp), and large entrance field area (1.7x - 2.3x, for the same object-plane field width). With improvements to the system geometry, detector, and x-ray source, SBDX technology is projected to achieve conventional cine-quality SNR over a full range of patient thicknesses, with 5-10 times lower skin dose.     

Comparison of unmonochromatized synchrotron radiation and conventional X-rays in the imaging of mammographic phantom and human breast specimens: a preliminary result

A simple imaging setup based on the principle of coherence-based contrast X-ray imaging with unmonochromatized synchrotron radiation was used for studying mammographic phantom and human breast specimens. The use of unmonochromatized synchrotron radiation simplifies the instrumentation, decreases the cost and makes the procedure simpler and potentially more suitable for clinical applications. The imaging systems consisted of changeable silicon wafer attenuators, a tungsten slit system, a CdWO4 scintillator screen, a CCD (Charge Coupled Device) camera coupled to optical magnification lenses, and a personal computer. In preliminary studies, a spatial resolution test pattern and glass capillary filled with air bubbles were imaged to evaluate the resOolution characteristics and coherence-based contrast enhancement. Both the spatial resolution and image quality of the proposed system were compared with those of a conventional mammography system in order to establish the characteristic advantages of this approach. The images obtained with the proposed system showed a resolution of at least 25 microm on the test pattern with much better contrast, while the images of the capillary filled with air bubbles revealed coherence-based edge enhancement. This result shows that the coherence-based contrast imaging system, which emphasizes the refraction effect from the edge of materials of different refractive indexes, is applicable to imaging studies in fundamental medicine and biology, although further research works will be required before it can be used for clinical applications.