人工心肺机血液泵监测系统的研制

为避免人工心肺机血液泵转速失控现像的发生，特研制人工心肺机监测系统，通过对血泵转速的实时监测，判断系统是否正常，自动进行相应的处理，提高现有系统的安全性。     

Potency variation of small-molecule chymase inhibitors across species

Chymases (EC 3.4.21.39) are mast cell serine proteinases that are variably expressed in different species and, in most cases, display either chymotryptic or elastolytic substrate specificity. Given that chymase inhibitors have emerged as potential therapeutic agents for treating various inflammatory, allergic, and cardiovascular disorders, it is important to understand interspecies differences of the enzymes as well as the behavior of inhibitors with them. We have expressed chymases from humans, macaques, dogs, sheep (MCP2 and MCP3), guinea pigs, and hamsters (HAM1 and HAM2) in baculovirus-infected insect cells. The enzymes were purified and characterized with kinetic constants by using chromogenic substrates. We evaluated in vitro the potency of five nonpeptide inhibitors, originally targeted against human chymase. The inhibitors exhibited remarkable cross-species variation of sensitivity, with the greatest potency observed against human and macaque chymases, with K_i values ranging from ∼0.4 to 72 nM. Compounds were 10-300-fold less potent, and in some instances ineffective, against chymases from the other species. The X-ray structure of one of the potent phosphinate inhibitors, JNJ-18054478, complexed with human chymase was solved at 1.8 Å resolution to further understand the binding mode. Subtle variations in the residues in the active site that are already known to influence chymase substrate specificity can also strongly affect the compound potency. The results are discussed in the context of selecting a suitable animal model to study compounds ultimately targeted for human chymase.     

PET/CT图像采集时间对图像质量和病灶检出率的影响

目的探讨在不影响图像质量和病灶检出率前提下缩短PET／CT图像采集时间的可行性。方法18例接受PET／CT检查的患者，在CT扫描后按1、2、3min／床位依次进行3次PET扫描，共得到54帧图像。患者按体重分为以下3组：（1）45～60kg（7例），（2）61～75kg（7例），（3）76～90k（4例）。由2位有经验的医师共同阅片确定每例患者病变的位置和数目，图像质量由2位医师独立判断。结果3min／床位PET／CT图像上共检出127个病灶，其中最小的病灶直径约为3mm，除1min／床位图像漏检3个病灶外，其他所有病灶均能被1min／床位、2min／床位的图像识别。（1）～（3）组患者在3min／床位采集图像上识别的病灶数分别为71、41、15个，第1组患者的所有病灶在3种不同采集时间图像上均能被识别，第2组患者1min／床位采集图像遗漏了3个病灶，而2min／床位图像识别出的病灶数与3min／床位图像相同。第3组患者的所有病灶在3种采集图像上也均能被识别。1、2min／床位的PET图像质量均较3min／床位图像差，1min／床位图像质量最差，主要表现为图像本底噪声高、对比度差。3组患者中，第3组患者图像质量最差。结论对体重低于60瞻患者，1～3min的采集时间，病变的检出率无明显差异；而对体重60k以上患者，建议选择2～3min／床位的采集时间，对病情较重或不合作患者，根据需要可考虑选择1min／床位的采集时间。     

骨样骨瘤的影像学诊断:X线平片与CT常规横断位及MPR比较

目的:比较常规X线平片、多层螺旋CT常规横断位及多平面重组(multi-planar reformation,MPR)在骨样骨瘤诊断中的价值。方法:回顾性分析41例骨样骨瘤病人在X线平片、CT常规横断位及MPR图像上的表现及其对瘤巢及瘤巢内钙化显示能力。结果:41例病灶均表现为一圆形或卵圆形的透亮区,其周围有不同程度的骨质硬化。41例中仅8例在X线平片上能显示瘤巢,瘤巢显示率为19.5%(8/41);所有检查者均清楚显示瘤巢周围骨质硬化,但均不能显示瘤巢内钙化;41例CT横断位图像及MPR图像均能清楚显示瘤巢,18例CT横断位图像能显示瘤巢内钙化,30例病人在MPR图像能显示瘤巢内钙化;横断位CT图像和MPR对瘤巢内钙化显示率分别为43.9%(18/41)和73.2%(30/41)。结论:瘤巢是确诊骨样骨瘤的关键,CT是显示瘤巢的重要检查方法,MPR图像是显示瘤巢内钙化的最佳方法,有助于做出准确诊断。     

对儿童X线体检中减少照射剂量的探讨

目的:探讨儿童在X线体检中减少照射剂量的方法。方法:应用东芝500mA遥控X线机、FJ-427型热释光剂量仪等设备,对100名3~5岁儿童体检时,随机分成两个对照组、每组50名,分别接受胸透或平片检查,对检查测得数据均进行统计学处理。结果:胸透时胸部接受的照射剂量是平片的22倍多,其它部位接受的X线散射剂量平均值之比亦在20~30倍之间。结论:在儿童X线体检中应采用常规胸片替代胸透,可以有效地降低其辐射危害。     

腹茧症的影像诊断

目的探讨腹茧症的影像特点，提高术前诊断水平。方法回顾性分析经手术病理证实的腹茧症6例，术前均进行立位腹部X线平片和腹部CT检查，4例同时行胃肠道钡剂造影，复习其影像表现。结果6例立位腹部X线平片中3例诊断为肠梗阻。4例胃肠道钡剂造影，均可见小肠交错盘绕成团，呈“菜花”状或“手风琴”状表现。6例CT检查，均可见小肠聚集成团，其周围可见膜样的囊状物将其包裹。结论对患者进行胃肠道造影时观察到“菜花”状征象，或CT检查时观察到小肠聚集成团被一层膜样物包裹，应考虑到腹茧症的可能。     

胸骨肿瘤CT诊断(附22例报告)

目的探讨胸骨肿瘤临床CT诊断和检查意义。方法搜集分析经临床病理证实的22例胸骨肿瘤CT资料,其中转移瘤17例(肺癌转移15例;乳腺癌转移2例)、骨髓瘤2例、软骨肉瘤1例、骨肉瘤1例、骨化性纤维瘤1例。结果局部骨质破坏(囊状膨胀性、溶骨性和混合性骨破坏3种),其中囊状膨胀性骨破坏1例(骨化性纤维瘤),溶骨性骨破坏16例(肺癌转移15例、骨肉瘤1例),混合性骨破坏5例(软骨肉瘤1例、骨髓瘤2例、乳腺癌转移2例)。胸骨处软组织肿块18例,胸骨前胸壁肌、皮下脂肪和胸骨后脂肪间隙浸润13例。结论胸骨肿瘤以转移瘤多见,CT检查对胸骨肿瘤有较高的诊断价值。     

CT结合内镜检查诊断胃肠道间质瘤的价值

目的：探讨CT结合内镜检查诊断胃肠道间质瘤(GIST)的价值。方法：回顾分析18例均经手术病理检验证实为GIST病人的CT及内镜检查资料。结果：(1)18例GIST的CT表现为类圆形或分叶状肿瘤，边界清楚，13例平扫及增强密度均匀，强化明显，5例瘤灶内有坏死液化区；肿瘤周围肠管不同程度受压移位或粘连。(2)15例源于胃、十二指肠及结肠的间质瘤均行内镜检查，4例瘤侧胃壁镜下所见黏膜呈外压性改变者未行咬检；11例伴有溃疡形成，溃疡处咬检获取病理组织。(3)18例均行手术后光镜观察及免疫组化检查，18例CD-117均为阳性，13例CD-34阳性，10例Vimentin阳性。结论：CT与内镜相结合检查，能提高胃、十二指肠及结肠GIST定位、定性的准确性。     

螺旋CT在小肾癌诊断中的价值

目的评价螺旋CT多期扫描在小肾癌诊断中的价值。方法收集经手术病理证实的小肾癌14例,分析其螺旋CT平扫、皮质期、实质期及肾盂期的表现。结果CT平扫病灶呈等密度7例,稍低密度5例,稍高密度1例,1例为囊实性肿块,其中2例伴斑点状钙化。增强扫描皮质期12例呈明显强化,2例呈轻中度强化。肾实质期肿瘤密度迅速减退,肾盂期肿瘤密度进一步减退。结论小肾癌螺旋CT增强多期扫描征象有一定特征性,对小肾癌的诊断有重要价值。     

Dentition planning with image-based occlusion analysis

Purpose To develop an easy-to-use, dentition planning method which is based on three-dimensional (3D) computer planning technology to replace conventional plaster-cast occlusion planning techniques. Methods The optimal dental occlusion is defined according to the condition of centric occlusion, i.e. after bringing occlusal surfaces of mandibular and opposing maxillary arches into identical 3D position. This identical position of occlusal surfaces represents the common reference frame for the 3D manipulation of all graphical elements. The planning procedure involves the following steps: (1) the optimal occlusal surface is approximated as triangle and localized both on the maxilla and mandible; (2) the original volumetric model is resampled according to the occlusal orientations; (3) the program reads in the models of ideal upper and lower dental arches from files, reshapes those to the patient anatomy and visualizes the local alignment on separate panels for mesiodistal and faciolingual inclinations. The final goal of the proposed method is to combine the requirements of functional and aesthetic designs and create an input for orthodontics, implantology and maxillofacial surgery. Results In the present study the optimal dental occlusion is created by image resampling after bringing the occlusal surfaces of mandibular and opposing maxillary arches into identical 3D position. This identical position of occlusal surfaces represents the common reference frame for manipulation of all graphical elements. Conclusions The proposed graphical environment was able to fit the elements of the ideal dentition curve to patient computed tomography under predefined centric occlusion. Rotation and scaling transformations of teeth were possible in the reformatted volumetric views about any of the axes of the teeth’s own reference space.