交链孢酚单甲醚对人淋巴细胞内环核苷酸水平的影响

淋巴细胞内环核苷酸水平的变化与免疫功能有关。交链孢酚单甲醚是食管癌高发区河南省林县粮食中分离中的主要污染菌互隔交链孢霉（亦称链格孢菌）的毒素之一，已有实验证实ＡＭＥ具有致突变性和致癌性。本实验从体外探讨了ＡＭＥ对人淋巴细胞内环核苷酸水平的影响。实验结果表明，ＡＭＥ能增高淋巴细胞内ｃＡＭＰ水平，不同浓度的ＡＭＥ在不同作用进点上，使细胞内ｃＡＭＰ含量比相应对照组升高１．５－２．０倍，并且在同一时点，随     

活兔颈椎稳定及椎板修补术的生物力学研究

本文在单向们伸状态下首次进行了活兔颈椎Ｃ３－Ｃ５（颈３－颈５）松弛，蠕变，单向拉伸破坏实验０活体（Ｃ３－Ｃ５）切除Ｃ４椎板的相应生物力学实验，Ｃ４椎板切除后用ＭＭＡ／Ｓ加ＭＭＡ（甲基丙烯酸甲酯共聚粉剂加甲基丙烯酸甲酯）修补的相应生物力学实验，根据活体实验，利用三参数模型，求出了活体颈椎（Ｃ３－Ｃ５）松弛模量，蠕变柔量，微分型和积分型材构方程，由实验得出：椎板切除后，颈椎稳定性受到破坏，椎板修补后，     

尿素—ＳＤＳ—ＰＡＧＥ快速测定多肽的相对分子质量

随阒电泳技术的不断改进和完善，该技术已成为现代分子生物学实验不可缺少的基本实验技术之一。然而进行小分子多肽的电泳分析时，由于其相对分子质量（Ｍr)小，易受电泳条件（电泳缓冲系统、凝胶浓度、电泳时间、染色和脱色等）的影响，极易引起条带扩散、不易着色。使分辨率降低，因而直接影响多肽Ｍr的测定，现有多肽Ｍr的电泳测定法［１，２］操作复杂，且结果也不理想，因此，我们经反复实验，建立了对Ｍr为２５００－１７０００多肽的尿素－ＳＤＳ－ＰＡＧＥ快速测定法。     

缺氧－复氧幼狗心肌细胞冷冻蚀刻电镜观察

本实验以幼狗心脏为实验对象，应用冷冻蚀刻技术观察ＡＴＰ－ＭｇＣｌ２对缺氧－复氧幼狗心肌细胞，尤其是膜结构的影响。结果表明，缺氧－复氧对照组心肌细胞损伤较重，而ＡＴＰ－ＭｇＣｌ２组心肌细胞损伤轻ｑ提示，ＡＴＰ－ＭｇＣｌ２对缺氧－复氧幼狗心肌细胞质膜、线粒体等超微结构有保护作用。     

确定HCMV抗药性实验方法研究进展

ＨＣＭＶ感染免疫妥协的机体，通常是无症状的，但在ＡＩＤＳ和骨髓，实质器官移植病人，是引起发病和死亡的主要原因之一，确定有毒力，对抗病毒药物产生抗性的ＨＣＭＶ株，对临床治疗ＨＣＭＶ感染引起的相关疾病很有必要，目前实验室用来确定ＨＣＭＶ抗药性敏感性实验方法有多种，且在不断改进和更新。本文对这些实验方法在临床上应用及其研究进展予以综述。     

血、尿中κ、λ轻链含量及比值在诊断多发性骨髓瘤中的应用

血、尿中κ、λ轻链含量及比值在诊断多发性骨髓瘤中的应用王兰兰１冯伟华１李立新１从多发性骨髓瘤（ＭｕｌｔｉｐｌｅＭｙｅｌｏｍａ，ＭＭ）患者血清、尿液中检出Ｍ蛋白并确定其含量与性质，是诊断ＭＭ的重要依据。我室过去对Ｍ蛋白的免疫学实验诊断多采用Ｉｇ分类定量...     

狗心肌梗塞面积计测的动物实验数学模型

狗心肌梗塞面积计测的动物实验数学模型△刘力曲直黄风娟（中国医科大学生物物理教研究，沈阳１１０００１）利用数学模型方法定量计测心肌梗塞面积（ＭｙｏｃａｒｄｉｏｌＩｎｆａｒｃｔＳｉｚｅ，ＭＩＳ）的大小、方位和性质，这里通过动物实验，在心脏左室后壁、下壁及...     

尿毒症患者血浆中分子物质对大鼠心肌舒缩性的抑制作用

目的：探讨尿毒症患者血浆中分子物质（ＭＭＳ），对大鼠心肌舒缩性的影响及心肌舒缩性改变的机制。方法：用凝胶层析法分离出ＭＭＳ，经尾静脉注入大鼠体内，实验用左心室插管术，采集信号经换能器数字化后输入微机，应用ＣＡＲＤＩＯ软件，分析注射ＭＭＳ前后心肌舒缩性的改变。结果：注射ＭＭＳ后，心室内压（ｐｅａｋ）下降，室内压达峰值时间（ｐｅａｋｔｉｍｅ）推迟，室内压最大上升变化率（ｄｐ／ｄｔｍａｘ）减小，室内压下降最大变化率（－ｄｐ／ｄｔｍａｘ）变慢，室内压下降最大变化速率所在时间（－ｄｐ／ｄｔｍａｘｔｉｍｅ）延长，上述变化在注射ＭＭＳ后１ｍｉｎ即出现，持续１２ｍｉｎ左右开始恢复。结论：ＭＭＳ可使心肌舒缩性能力减弱，说明ＭＭＳ对大鼠心肌舒缩性具有抑制作用     

一种快速、简便、敏感、特异的白细胞介素2、3、6生物学检测法：MTS／PMS法的建立

ＭＴＴ的一种新型类似物ＭＴＳ在ＰＭＳ存在情况下可被活细胞还原，形成水溶性甲产物。本实验表明，将ＭＴＳ／ＰＭＳ取代ＭＴＴ用于ＩＬ－２、３、６生物学测定法取得理想结果，ＭＴＳ／ＰＭ５形成的比色产物与细胞数量、ＭＴＳ／ＰＭＳ与细胞孵育时间呈正相关。ＭＴＳ／ＰＭＳ生物学测定法省略了加有机溶剂溶解甲的步骤，ＭＴＳ／ＰＭ５贮存稳定、显色快速，故该法具有快速、简便敏感、特异的优点，适用于细胞因子的生物学测定。     

缺氧——复氧幼狗心肌细胞冷冻蚀刻电镜观察

本实验以幼狗心脏为实验对象，应用冷冻蚀刻技术观察ＡＴＰ－ＭｇＣｌ２对缺氧－复氧幼狗心肌细胞，尤其是膜结构的影响。结果表明，缺氧－复氧对照组心肌细胞损伤较重，而ＡＴＰ－ＭｇＣｌ２组心肌细胞损伤轻。提示，ＡＴＰ－ＭｇＣｌ２对缺氧－复氧幼狗心肌细胞质膜、线粒体等超微结构有保护作用。     

Determination of the source position for the electron beams from a high-energy linear accelerator

We have investigated the energy and field-size dependence of the source position of the electron beams from a Varian Clinac-2,500 accelerator. Three independent experimental methods were used: (1) multipinhole camera (MPC), (2) back projection of the full width at half maximum (FWHM), and (3) the inverse square law (ISL). The positions of the virtual and effective sources were calculated using the multiple Coulomb scattering (MCS) formalism. The results obtained from the MPC agree, within the experimental uncertainties, with the calculated values for the virtual source position. Similarly, the results from the FWHM method agree with the calculations with the exception of those for small field sizes at the lower energies. This is consistent with the fact that both kinds of measurements are not very sensitive to scattering in the photon and electron collimators. In contrast, the source position determined by the ISL method shows strong dependence on field size and energy, and does not agree with the values predicted by the MCS formalism. This is due to contamination from electrons scattered in the x ray and electron collimation system. The techniques and results reported here should be generally applicable to other scatter foil linear accelerators.     

The diagnostic capability of x-ray scattering parameters for the characterization of breast cancer

PURPOSE: The evaluation of the diagnostic capability of easy to measure x-ray scattering profile characterization parameters for the detection of breast cancer in excised samples. The selected parameters are the full width at half maximum (FWHM) and area under the x-ray scattering profile of breast tissue in addition to the ratio of scattering intensities (I2/I1%) at 1.6 nm(-1) to that at 1.1 nm(-1) (corresponding to scattering from soft and adipose tissues, respectively). Methods: A histopathologist is asked to classify 36 excised breast tissue samples into healthy or malignant. A conventional x-ray diffractometer is used to acquire the scattering profiles of the investigated samples. The values of three profile characterization parameters are calculated and the diagnostic capability of each is evaluated by determining the optimal cutoffs of scatter diagrams, calculating the diagnostic indices, and plotting the receiver operating characteristic (ROC) curves. Results: At the calculated optimal cutoff for each of the examined parameters, the sensitivity ranged from 78% (for area under curve) up to 94% (for FWHM), the specificity ranged from 94% [for I2/I1% and area under curve] up to 100% (for FWHM), and the diagnostic accuracy ranged from 86% (for area under curve) up to 97% (for FWHM). The area under the ROC curves is greater than 0.95 for all of the investigated parameters, reflecting a highly accurate diagnostic performance. Conclusions: The discussed tests offered a means to quantitatively evaluate the performance of the suggested breast tissue x-ray scattering characterization parameters. The performance results are promising, indicating that the evaluated parameters would be considered a tool for fast, on spot probing of breast cancer in excised tissue samples.     

Low-angle X-ray scattering from lyophilized blood constituents

The characteristic nature of low-angle x-ray scattering from biological samples and its dependence on molecular structure is a subject of increasing interest. In this work, low-angle x-ray scattering from lyophilized (freeze-dried) whole blood, haemoglobin (Hb), serum and red blood cell membranes is studied. The scattering profiles of these samples are found to be reproducible and characteristic. A number of characterization parameters are introduced, showing significant differences between the investigated samples. The sensitivity of the scattering profiles of whole blood, Hb and serum towards induced molecular level variations is examined after doses of gamma irradiation of 3, 6 and 9 Gy. The full width at half maximum (FWHM) of the second peak of scattering and the percentage ratio of amplitudes of the first and second peaks (I1/I2)% are found to be the parameters most sensitive to irradiation. For all irradiated samples, it is observed that the FWHM of the second peak is always greater than the control, while the ratio (I1/I2)% is always smaller than the control.     

Design of a very high-resolution small animal PET scanner using a silicon scatter detector insert

A small animal positron emission tomography (PET) instrument using a high-resolution solid-state detector insert in a conventional PET system was investigated for its potential to achieve sub-millimeter spatial resolution for mouse imaging. Monte Carlo simulations were used to estimate the effect of detector configurations (thickness, length and radius) on sensitivity. From this initial study, a PET system having an inner cylindrical silicon detector (4 cm ID, 4 cm length and 1.6 cm thickness composed of 16 layers of 300 microm x 300 microm x 1 mm pads), for scattering, surrounded by an outer cylindrical BGO scintillation detector (17.6 cm ID, 16 cm length and 2 cm thickness segmented into 3 mm x 3 mm x 20 mm crystals), for capture was evaluated in detail. In order to evaluate spatial resolution, sensitivity and image quality of the PET system, 2D images of multiple point and cylinder sources were reconstructed with the simulation data including blurring from positron range and annihilation photon acollinearity using filtered backprojection (FBP). Simulation results for (18)F demonstrate 340 microm FWHM at the center of the field of view with 1.0% sensitivity from the coincidence of single scattering events in both silicon detectors and 1.0 mm FWHM with 9.0% sensitivity from the coincidence of single scattering in the silicon and full energy absorption of the second photon in the BGO detector.     

侧向电子失衡对肺部肿瘤放射治疗计划设计的影响

目的 :分析高能X射线通过低密度的肺组织时 ,侧向电子失衡对肺部肿瘤放射治疗计划的影响。方法 :用 6MV和 18MVX射线对一例肺癌进行三维适形治疗 (3D CRT)计划设计 ,并用Helax TMS计划系统提供的笔形束算法和筒串算法对两种能量下的布野方案相同的 3D CRT计划进行剂量计算 ,比较靶区及危及器官的剂量分布、DVH等指标。结果 :采用笔形束算法 6MV与 18MV计划的等剂量线和DVH相近 ,18MV计划的靶区剂量均匀性略优于 6MV计划 ;而当采用能进行电子侧向散射修正的筒串算法时 ,靶区的高剂量覆盖程度明显变差 ,18MV计划靶区剂量亏损更为显著 ,6MV计划高剂量覆盖靶区的程度优于 18MV计划 ;不同能量、算法下肺和脊髓的受量基本相同。结论 :对于肺部肿瘤 ,剂量计算应采用能够准确修正不均匀组织影响的算法 ,非调强放射治疗时最好使用 6MVX射线。     

Measurement of CT radiation profile width using CR imaging plates

This paper describes the procedure for using a Fuji computed radiography (CR) imaging plate (IP) for the measurement of computed tomography (CT) radiation profiles. Two sources of saturation in the data from the IP, signal and quantization, were characterized to establish appropriate exposure and processing conditions for accurate measurements. The IP generated similar profiles compared to those obtained from digitized ready-pack films, except at the profile edges, where the exposure level is low. However, when IP pixel values are converted to exposure, CR and digitized film profiles are in agreement. The full width at half maximum (FWHM) of the CT radiation profile was determined from the relationship between pixel value and exposure and compared to FWHM of the digitized optical density profile from film. To estimate the effect of scattering by the cassette material, radiation profiles were acquired from IPs enclosed in a cassette or in a paper envelope. The presence of the cassette made no difference in the value determined for FWHM. With proper exposure and processing conditions, the FWHM of 5, 10, and 15 mm collimated beams were measured using IPs to be 7.1, 11.9, and 17.0 mm and using film to be 7.2, 12.2, and 16.8 mm, respectively. Our results suggest that, under appropriate conditions, the estimation of the width of the CT radiation profile using Fuji CR is comparable to the measurement from film density described in American Association of Physicists in Medicine (AAPM) Report No. 39. Although our experiment was conducted using Fuji CR, we anticipate that CR plates from other vendors could be successfully used to measure CT beam profiles because of similar empirical relationships between pixel value and exposure.     

SPECT成像空间分辨率的测量与评价

作者使用ＳＰＥＣＴ性能体模和ＮＥＭＡ三线源分辨体模等标准化仪器，对一台日本进口的ＳＰＥＣＴ设备进行了空间分辨率测量。基本方法是对采集的线源平面影像和断层影像取计数分布曲线（ｐｒｏｆｉｌｅ）并求出半高宽（ＦＷＨＭ），即以线源失锐值作为空间分辨率定量。结果表明：（１）平面分辨率合格但未达到标称值；（２）散射媒质的影响是空间分辨率下降的原因；（３）偏心线源断层影像具有几何非对称性，径向半高宽大于切向半高宽，而且两者的差值呈现各向异性；（４）断层分辨率随探头旋转半径的增大而下降．把圆轨道改为椭圆轨道，可以改善空间分辨率；（５）断层扫描时，冷灶影像的分辨率优于热灶影像，等等。本文对测量结果进行分析，并参照现行标准作出评价。     

豚鼠脊髓腹角神经元线状溶酶体酶细胞化学研究及其电子探针X射线能谱分析

为探讨豚鼠脊髓腹角神经元是否存在线状溶酶体及其酶细胞化学活性分布特点，用偏磷酸酶（Ｍｅｔａｐｈｏｓｐｈａｔａｓｅ，ＭＰａｓｅ）和酸性磷酸酶（Ａｃｉｄｐｈｏｓｐｈａｔａｓｅ，ＡＣＰａｓｅ）电镜细胞化学方法和电子探针Ｘ射线能谱分析技术，证实豚鼠脊髓腹角神经元存在线状溶酶体（Ｎｅｍａｔｏｌｙｓｏｓｏｍｅ，ＮＬＹ），同时于原位测定ＮＬＹ内的铅含量以反映酶活性强弱。ＭＰａｓｅ和ＡＣＰａｓｅ反应产物分布于圆形溶酶体和ＮＬＹ，同时在高尔基复合体的部分扁囊也有酶活性，表明该酶是在高尔基复合体上加工后输送至溶酶体。在神经元胞体、突起及突触前成分中均有呈ＭＰａｓｅ阳性和ＡＣＰａｓｅ阳性的ＮＬＹ的分布，并和线粒体紧密相贴，提示酶是由线粒体提供能量的ＮＬＹ从胞体输送到神经终末，可能参与神经递质的降解及神经元代谢物质的处理。电子探针Ｘ射线能谱分析测定结果，ＭＰａｓｅ活性强于ＡＣＰａｓｅ活性，提示ＭＰａｓｅ是比ＡＣ－Ｐａｓｅ更为敏感的溶酶体标志酶     

红外线及特定电磁波辐照对小鼠周围血象的影响

经红外线及特写电磁波（ＴＤＰ）辐照的小鼠周围血象与对照组比较，红外线１５分钟组的淋巴细胞占白细胞分类的百分比，ＴＤＰ１５分钟组与ＴＤＰ３０分钟组的白细胞总数及淋巴细胞占白细胞分类的百分比均明显增高。提示一定剂量的红外线及ＴＤＰ辐照有增强机体免疫功能的效应。     

Coherent scattering and bone mineral measurement: the dependence of sensitivity on angle and energy

The sensitivity of a technique for the measurement of trabecular bone mineral concentration has been examined theoretically and experimentally. The technique is based on coherent gamma ray scattering and corrections for attenuation are obtained from transmitted photons rather than Compton scattered photons. For an incident photon energy of 60 keV, the minimum detectable bone mineral difference is practically independent of scattering angle while for an incident energy of 100 or 122 keV the scattering angle must be less than 70 degrees to optimize the minimum detectable difference.