人内质网分子伴侣BiP的克隆、表达及其在RA患者血清抗体检测中的作用

以类风湿关节炎(rheumatoid arthritis,RA)患者滑膜组织文库cDNA为模板,用PCR方法扩增得到1965 bp人内质网分子伴侣BiP的全长cDNA,将其克隆入OmicsLinkTM表达载体pReceiver-B01a,构建重组表达质粒pReceiver-B01a-BiP。重组表达质粒导入大肠杆菌BL-21(DE3)菌株中诱导表达目的蛋白,表达产物以Ni+-NTA agarose层析柱纯化。SDS-PAGE和免疫印迹法(Western blot)分析发现,表达产物以可溶性蛋白和包涵体形式共同存在,表达量约占菌体蛋白总量的20%~30%。相对分子质量约为80000,纯度达到电泳级。经免疫印迹法鉴定,获得的BiP重组蛋白可以与RA患者血清反应,检测的抗BiP抗体在RA患者血清中的阳性率为75.4%(49/65),明显高于系统性红斑狼疮(systemic lupus erythe-matosus,SLE)患者14.6%(7/48)、原发性干燥综合征(primary Sj gren’s syndrome,pSS)患者7.3%(4/55)及正常人0%(0/71)(P<0.01)。表明,经原核表达获得的BiP全长蛋白,RA患者血清抗体可以很好结合,有望应用于临床血清学诊断。     

Oxygen Tension Imaging in the Mouse Retina

A newly developed microscope-based imaging system was used to measure the oxygen tension (PO₂) inside the retinal and choroidal vessels of mice and to generate in vivo maps of retinal PO₂. These maps were generated from the phosphorescence lifetimes of an injected palladium–porphyrin compound using a frequency-domain measurement. The system was fully calibrated and used to produce retinal PO₂ maps at different inspiratory oxygen fractions. PO₂ rose accordingly and predictably as inspiratory O₂ was stepped from hypoxic to hyperoxic conditions. Important experimental and acquisition parameters necessary for applying phosphorescence lifetime imaging to the mouse eye were investigated, including camera exposure and intensifier gain settings. Because of a need to limit light exposure to the retina, PO₂ map quality as measured by the coefficient of determination was investigated as a function of signal-to-noise and accumulated excitation energy deposition. With the development of this technology for use in mice, the potential for investigating the oxygen dynamics in genetically engineered mouse models of retinal disease, including diabetic retinopathy, glaucoma, and age-related macular degeneration, is advanced. © 2003 Biomedical Engineering Society. PAC2003: 4266Ew, 8763Lk, 8719Dd     

How many lymph nodes are necessary to stage early and advanced adenocarcinoma of the sigmoid colon and upper rectum?

The lymph-node yields in specimens resected for colorectal adenocarcinoma show considerable variations, raising the question whether the minimum lymph-node number recommended by the UICC (International Union Against Cancer) for pN0 classification represents an appropriate quality standard for specimen work-up. The number of pericolic lymph nodes recovered from 568 archival surgical colorectal carcinoma specimens located in the sigmoid or upper rectum showed a highly statistically significant correlation with both the pT category and the presence of metastases (P<0.0005). The median lymph-node yield in standardized (i.e., resembling in size surgically removed cancer specimens) tumor-free specimens obtained during autopsies was 13 lymph nodes, compared with 20.5 when diverticula were present and more than 30 in specimens with chronic inflammation or from patients with systemic infections. In 48 pT2 and pT3 carcinoma specimens prospectively dissected in the same way, median numbers of 18 (pT2) and 23 (pT3) lymph nodes were detected (range between 8 and 39 nodes). The lymph-node numbers recommended in previous studies and by the UICC often seem to be too low to declare a specimen free of metastases. Although the great variation in lymph-node counts requires the recovery of all lymph nodes for pN0 classification, recommendations considering the pT status and additional factors like diverticula and inflammatory changes can be useful as a quality standard for specimen work up.     

颈椎病患者经颅多普勒检查与头颅CT和脑电图的关系

应用多普勒技术对50例确诊为椎动脉型颈椎病的患者进行了检查,结果30例异常。其中25例主要表现为不同程度的双侧颈动脉血流量对称性偏低,管径及头颅CT无异常,脑电图部分改变,主要表现为低幅慢波,经治疗后症状改善,多普勒复查正常,说明CT正常不能否定脑缺性血管病的存在,CT不能代替多普勒检查,另5例主要表现为双侧颈动脉血流量不对称,其中3例为双侧血管经狭窄,CT提示全脑萎缩,脑电图呈低幅慢波;另2例CT提示左颞后顶区,右枕外侧区梗塞,脑电图及脑电地形图表现相应部位慢波灶达6～7级。CT异常者,临床治疗效果欠佳,多普勒检查和脑电图及临床症状变化不大,故多普勒检查对监测脑动力循环有一定意义。     

Detection of hepatitis B surface antigen (HBsAg) in peripheral blood mononuclear cells of patients with acute and chronic active hepatitis B

Seventy five patients with acute and chronic active hepatitis (CAH) were studied by indirect immunofluorescence with monoclonal antibodies for the presence of hepatitis B surface antigen (HBsAg) on peripheral blood mononuclear cells (PBMC). The viral surface antigen was detected in the PBMC of all the patients with hepatitis B virus (HBV)-induced CAH and in acute patients with more than 2 months of evolution. No HBsAg was detected in the samples obtained from 12 normal controls or from 14 non-A, non-B CAH patients. Analysis of PBMC subsets revealed that HBsAg was present in non-T cells; dual fluorescence studies showed HBsAg on surface Ig-positive lymphocytes. The binding of anti-HBs monoclonal antibodies was higher than that of a goat anti-HBs serum, and the highest reactivity was observed with an antibody against the pre-S(2)-region sequence. Both HBsAg and hepatitis B core antigen (HBcAg) were also detected in lysates of PBMC by dot blot analysis.     

Restriction endonuclease fingerprinting enhanced conformation sensitive gel electrophoresis (REF-CSGE) in the analysis of BRCA1 exon 11 mutations in a high-risk breast cancer cohort

Efficient genetic analysis of large exonic regions containing heterozygous mutations and common polymorphisms can be difficult. We have analyzed 30 patients for inherited susceptibility mutations (ISM) within exon 11 of the BRCA1 gene as part of an ongoing genetic epidemiological study of high-risk breast cancer (HRBC). A novel combination of restriction endonuclease fingerprinting (REF) and conformation sensitive gel electrophoresis (CSGE) was developed for rapid and efficient screening of mutations. This method (REF-CSGE) was compared side-by-side with standard CSGE and evaluated for both efficiency and sensitivity of detection. REF-CSGE detected 100% of the alterations found by CSGE. However, one variant was only detectable by REF-CSGE. All samples with variant bands were sequenced to confirm the nature of the alteration. In total, two small deletions (frameshifts) and 62 point mutations (60 known polymorphisms and two variants of unknown significance) were found in our cohort. The majority of the exon 11 polymorphisms detected are inherited as a linked haplotype. Point mutations that comprise these haplotypes could be simultaneously detected on a single gel by REF-CSGE, thereby decreasing the number of sequencing reactions necessary to elucidate heteroduplex patterns seen on CSGE gels. An analysis of the overall efficiency of both techniques revealed that REF-CSGE required 67% fewer confirmatory sequencing reactions, resulting in savings in both reagents and technician time.     

独立分量分析在乳腺钼靶X片感兴趣区域提取中的应用

为乳腺癌早期诊断和乳腺X线影像微钙化点计算机辅助检测的前期预处理,本研究提出基于独立分量分析（ICA）的自动提取新算法并且将其应用于乳腺图像感兴趣区域的自动提取.其具体思路是：（1）将乳腺区域图像提取成等大的子图像作为待测乳腺图像感兴趣区域;（2）将ICA应用于乳腺图像感兴趣区域得到基图像;（3）将待识别乳腺图像感兴趣区域在基图像所构成的子空间进行投影求得待测乳腺图像感兴趣区域的特征矢量;（4）用人工神经网络分类方法进行乳腺图像感兴趣区域的模式判别.对临床实际病例的试验结果表明,该方法的检出率为91%,与同类研究检出率相当.本研究方法简单有效,并具有较高的智能性,为ROI的自动提取提供了新的研究思路.     

虚拟咬合运动初步仿真模拟的研究与实现

我们试验了利用VR技术进行虚拟咬合仿真制作的全部过程。首先,采用光学三维测量仪对上下颌石膏模型进行数字化,通过预处理获取有效的三角网格曲面模型;其次,对咬合运动模型进行合理的简化,分解为一系列的平移运动和旋转运动;通过动态刷新完成开闭口运动、侧移运动的计算机运动仿真,可视化地观察咬合运动;然后利用模型碰撞检测算法动态地计算咬合接触位,并详细地分析了咬合接触时的咬合点位置分布和咬合剖切面上的咬合点接触关系;最后讨论了目前虚拟咬合仿真存在的问题和今后研究的方向。     

Impact of Breast Density on Computer-Aided Detection in Full-Field Digital Mammography

The goal of this study was to evaluate the performance of a computer-aided detection (CAD) system in full-field digital mammography (Senographe 2000D, General Electric, Buc, France) in finding out carcinomas depending on the parenchymal density. A total of 226 mediolateral oblique (MLO) and 186 craniocaudal (CC) mammographic views of histologically proven cancers were retrospectively evaluated with a digital CAD system (ImageChecker V2.3 R2 Technology, Los Altos, CA, USA). Malignant tumors were detected correctly by CAD in MLO view in 84.85% in breasts with parenchymal tissue density of the American College of Radiology (ACR) type 1, in 70.33% of the ACR type 2, in 68.12% of the ACR type 3, and in 69.70% of the ACR type 4. For the CC view, similar results were found according to the ACR types. Using the chi-square and McNemar tests, there was no statistical significance. However, a trend of better detection could be seen with decreasing ACR type. In conclusion, there seems to be a tendency for breast tissue density to affect the detection rate of breast cancer when using the CAD system.     

Design and application of sensor for recording sounds over human eye and nose

The recording of sounds over the oribt of the eye has been found to be useful in the detection of intracranial aneurysms. A hydrophone for auscultation over the eye has been developed and is tested under controlled conditions. The tests consist of measurement over the eyes in three healthy volunteers at rest, during voluntary breathing, during eyeball movements and during sustained orbicular muscular contractions. Furthermore, measurements are performed at the side of the nose. Major features of the hydrophonic transducer are high sensitivity to physiological sounds and a high degree of insensitivity to environmental sounds propagated through the air. It can be concluded that the hydrophone may be useful for the early detection of intracranial aneurysms and also for apnoea detection.