磁共振成像对胸膜外脂肪显示的研究

目的：研究MRI对正常及异常胸膜外脂肪显示的价值。材料和方法：对21例健康志愿者进行了MRI化学位移同相位成像、反相位成像、T1WI、T2WI及STIR序列扫描，并对胸膜外脂肪的绝对信号强度及信号强度比进行比较分析，同时还对20例累及胸膜外脂肪的病人进行检查。结果：在MRI各序列中，化学位移反相位成像显示胸膜外脂肪最佳，各序列绝对信号强度没有差别，而信号强度比存在差异。异常的胸膜外脂肪可以表现为移位、受压、中断、增厚及信号改变。结论：MRI可以作为观察正常及异常胸膜外脂肪的有效检查方法。     

急性脑梗死后血浆NO、NOS、ET含量的动态变化及尼莫地平对其影响

目的　观察急性脑梗死 (ACI)后血浆一氧化氮 (NO)、一氧化氮合成酶 (NOS)、内皮素 (ET)含量的动态变化 ,以及尼莫地平治疗后对其影响。方法　ACI患者 110例 ,随机分成尼莫地平组 (5 0例 ) (在常规治疗基础上用尼莫地平 )和常规治疗组 (6 0例 )。在发病后不同时点动态观察血浆NO、NOS、ET含量 ,并设 5 0例脑动脉硬化患者为对照组。结果　脑梗死后血浆ET含量显著升高 ,直至恢复期 ;NO、NOS先增高后下降 ;尼莫地平组和常规组比较ET有显著差异 (P <0 .0 1) ,NO、NOS差别不显著 (P >0 .0 5 )。结论　NO、NOS、ET参与并影响了ACI后复杂的病理生理过程 ;尼莫地平部分通过对ET含量的影响发挥其对脑梗死的治疗作用     

Histochemical study of colorectal adenocarcinoma by fluorescein isothiocyanate (FITC) conjugated lectins

Binding of FITC conjugated lectins to mucin in benign and malignant colon lesions was studied by fluorescence microscopy. In 145 cases of colonic adenocarcinoma, PNA (peanut agglutinin) was found to be bound to 75% of cases, while DBA (dolichos biflorus agglutinin) to 13% only. By contrast, DBA was bound to 94% of normal colon mucosa, while PNA to 15% only. Chronic colitis, simple adenoma and inflammatory polyps had the same binding pattern as normal mucosa, but villous adenoma, mixed polyps and multiple polyposis which are considered as premalignant lesions in colon had high positive rate of PNA binding and low binding percentage of DBA. These results indicate that an exposed carbohydrate structure Gal B1-2----GlNAc is expressed in the mucin produced by colonic adenocarcinoma. Meanwhile, some normal mucin component disappears from the malignant colonic epithelium. The mechanism of alteration of human colonic mucin present in malignant transformation is briefly discussed.     

B组轮状病毒WH-2株vp7基因的原核表达与抗体的制备

目的：在大肠杆菌中表达人B组轮状病毒WH-2株VP7蛋白并制备其兔抗血清。方法：根据B组轮状病毒（GBRV）WH-2株vp7基因的全序列设计引物,用PCR的方法扩增得到vp7基因的编码区。将其克隆到原核GST融合表达载体pGEX-KG内,转化大肠杆菌E.coliDH5α,IPTG诱导表达人B组轮状病毒WH-2株VP7蛋白,经SDS-PAGE分离纯化表达的蛋白免疫新西兰兔,制备人B组轮状病毒WH-2株VP7蛋白抗血清。结果：经鉴定确认,vp7基因以正确的方式插入到载体中,此重组表达载体经IPTG诱导后,可表达相对分子量为53.4 kDa的GST-VP7融合蛋白。制备的抗血清经同样诱导表达的表达载体pGEX-KG表达产物吸收后1：500倍稀释后用Western Blot分析,与53.4 kDa的GST-VP7融合蛋白获得特异性显色信号。结论：人B组轮状病毒WH-2株VP7蛋白成功在大肠杆菌中GST融合表达,所表达的蛋白和制备的抗体不但为研究结构与功能提供了物质基础,也为GBRV所引起的疾病预防、诊断和治疗等流行病学研究和临床诊断奠定了基础,具有重要实际应用价值。     

Data compression: effect on diagnostic accuracy in digital chest radiography

High-resolution digital images make up very large data sets that are relatively slow to transmit and expensive to store. Data compression techniques are being developed to address this problem, but significant image deterioration can occur at high compression ratios. In this study, the authors evaluated a form of adaptive block cosine transform coding, a new compression technique that allows considerable compression of digital radiographs with minimal degradation of image quality. To determine the effect of data compression on diagnostic accuracy, observer tests were performed with 60 digitized chest radiographs (2,048 x 2,048 matrix, 1,024 shades of gray) containing subtle examples of pneumothorax, interstitial infiltrate, nodules, and bone lesions. Radiographs with no compression, with 25:1 compression, and with 50:1 compression ratios were presented in randomized order to 12 radiologists. The results suggest that, with this compression scheme, compression ratios as high as 25:1 may be acceptable for primary diagnosis in chest radiology.     

全国细菌药敏试验的室间质量评价

目的：了解全国大中型医院细菌药敏试验（AST）状况，提高检测水平和质量。方法：定期向全国各参加评价实验室发放冻干标本，要求在规定时间内报告可疑感染的病原菌及其药敏结果，对回报结果给予数据统计、分析和评价。结果：2000年全国489个细菌室对常见耐药菌的检测正确率分别为：超广谱β－内酰胺酶63％（ESBLs)；苯唑西林敏感金黄色葡萄球菌（MSSA）74％；苯唑西林耐药凝固酶阴性葡萄球菌（MRSCoN)48％；对青霉素不敏感肺炎链球菌7％；氨基糖苷类高水平耐药肠球菌95％；产β－内酰胺酶流感嗜血杆菌正确率35％。结论：通过细菌药敏试验的室间质量评价反映出我国的细菌耐药性检测水平急待提高。     

沙土鼠短暂性脑缺血后海马损伤的形态学特征

本实验通过结扎沙土鼠双侧颈总动脉20分钟,再灌流7天内,动态观察背侧海马组织的形态学变化。光镜观察表明:海马各区对缺血的反应性不同,其中以 CA_1区锥体细胞对缺血最为敏感,并且 CA_1区神经元的损伤是迟发性的,再灌流4天后才出现大量神经元的坏死、消失,即“迟发性神经元死亡”(NDN)。电镜下发现:缺血再灌流早期(1～2天),CA_1区神经细胞质内有大量粗面内质网增多。本实验结果表明:短暂性脑缺血所致的海马损伤与脑组织其他区域神经元损伤不同。     

Mechanisms of protective action of radix Salviae miltiorrhizae (RSM) against experimental hepatic injury in rats]

The results indicated that RSM could significantly inhibit the lipid peroxidation of normal livers and cultured hepatocytes of rats, induce liver microsomal cytochrome P450 in normal rats, increase nucleic acids, proteins, urea and cerolloplasmin of damaged cultured hepatocytes of rats, relieve ultrastructural damage of cultured hepatocytes induced by CCl4. The pharmacological actions mentioned above should be considered as important mechanisms of RSM against liver injury.     

In-plane myocardial wall stress is not the primary determinant of coronary systolic flow impediment. A study in the isolated, perfused dog septum.

The hypothesis that ventricular in-plane tensile wall stresses are the major determinant of systolic coronary flow was investigated in this study. We measured coronary artery inflow in the maximally vasodilated bed of the isolated beating septum (n = 10) during two modes of contraction characterized by markedly different levels of developed in-plane stress. An increase in contractility was induced by changing from the control steady-state pacing state to a postextrasystolic potentiated state induced by a modified rapid pacing protocol. Over a range of increments of passive stretch, the systolic flow impediment versus the diastolic wall strain was described by an inverse linear relation. Despite the differences in developed in-plane wall stresses between the two modes of contraction (p less than 0.001), the slope and intercept of these relations in both the control and potentiated states were not different for the low versus high developed stress modes. The systolic flow impediment versus diastolic wall strain relation for the potentiated beats, compared with the control beats, was characterized by an increase in the intercept in both the low developed stress beats (p less than 0.05) and the high developed stress beats (p less than 0.05). These data indicate that the impediment to coronary flow during systole is not primarily determined by systolic myocardial in-plane tensile wall stresses but rather by the contractile state of the muscle.     

腹部CTA检查的质量保证

目的:探讨螺旋CT血管造影(Spiral CT angiography,SCTA)技术,以期提高SCTA造影的质量。材料与方法:采用Somatom Plus 4螺旋CT扫描系统对10例病人行腹部SCTA检查。扫描技术和造影剂参数按病变范围和性质而定,三维重建采用最大强度投影法(MIP)或表面阴影显示法(SSD)或弯曲平面重建法(CPR)。结果:SCTA检查技术能可靠地显示血管形态和病变,评价腹部肿瘤与邻近血管关系。结论:SCTA是无创伤性的血管成像术,在很大范围可替代创伤性的血管造影。