Dynamic programming in parallel boundary detection with application to ultrasound intima-media segmentation

Segmentation of carotid artery intima-media in longitudinal ultrasound images for measuring its thickness to predict cardiovascular diseases can be simplified as detecting two nearly parallel boundaries within a certain distance range, when plaque with irregular shapes is not considered. In this paper, we improve the implementation of two dynamic programming (DP) based approaches to parallel boundary detection, dual dynamic programming (DDP) and piecewise linear dual dynamic programming (PL-DDP). Then, a novel DP based approach, dual line detection (DLD), which translates the original 2-D curve position to a 4-D parameter space representing two line segments in a local image segment, is proposed to solve the problem while maintaining efficiency and rotation invariance. To apply the DLD to ultrasound intima-media segmentation, it is imbedded in a framework that employs an edge map obtained from multiplication of the responses of two edge detectors with different scales and a coupled snake model that simultaneously deforms the two contours for maintaining parallelism. The experimental results on synthetic images and carotid arteries of clinical ultrasound images indicate improved performance of the proposed DLD compared to DDP and PL-DDP, with respect to accuracy and efficiency.     

A Multiple Imputation Approach for Estimating Rank Correlation With Left-Censored Data

Frequently the correlation between two different measures of viral load obtained from each of a sample of patients is assessed in HIV studies. Kendall’s tau and Spearman’s rank correlations are often used for this assessment instead of Pearson’s correlation coefficient as they are not affected by outliers and nonnormality. However, such viral load data may be subject to left censoring due to values below assay detection limits. In this situation the usual estimators for the rank correlations (based on assigning ties to the values below the detection limits) may be severely biased. We propose a multiple imputation approach using a truncated bivariate normal model for imputation. Simulation results indicate that the imputation estimates are apparently unbiased for bivariate normally distributed data and still perform well if the data are misspecified.     

The impact of cataract on the quantitative,non‐invasive assessment of retinal blood Flow

Purpose: The aim of the study was to determine the impact of cataract on the quantitative, non‐invasive assessment of retinal blood flow assessed by bidirectional laser Doppler flowmetry and simultaneous vessel densitometry. Methodology: Ten patients scheduled for extracapsular cataract extraction using phacoemulsification and intraocular lens implantation between the ages of 61 and 84 (mean age 73 years, SD ± 8) were prospectively recruited. Two visits were required to complete the study; one visit prior to extracapsular cataract extraction and one at least 6 weeks after the surgery to allow for sufficient postoperative recovery. The severity of cataract was documented using the Lens Opacity Classification System (LOCS, III) at the first visit. Retinal arteriolar hemodynamics were measured at both visits using the high‐intensity setting of the Canon Laser Blood Flowmeter. Results: All eyes showed no clinical signs of postoperative intraocular inflammation. The quantitative assessment of retinal arteriolar diameter and blood flow were reduced following extracapsular cataract extraction (Wilcoxon signed‐rank test, p = 0.022 and p = 0.028, respectively); however, centreline blood velocity was not significantly changed (Wilcoxon signed‐rank test, p = 0.074). Intraocular pressure was unchanged pre‐ and postcataract extraction. Conclusions: Retinal vessel densitometry assessment in the presence of cataract results in the erroneous elevation of the diameter measurement and thereby the calculation of blood flow. The bidirectional Doppler assessment of blood velocity appears to be more robust to light scatter induced by cataract. Care needs to be exercised in the interpretation of studies of retinal vessel diameter or blood flow that utilize similar densitometry techniques.     

慢性前列腺炎患者进行病原微生物检测与药敏试验的意义

目的探讨慢性前列腺炎患者进行病原微生物检测与药敏试验的意义。方法89例慢性前列腺炎患者,均进行病原微生物检测,对病原微生物检测结果为阳性的患者进行药敏试验,统计和分析其对抗生素的药敏试验结果。结果89例患者进行了病原微生物检测后,有29例患者检测结果呈现支原体阳性,占比33%,其中有8例为人型支原体检测呈阳性,占阳性患者总数的28%,有21例为解脲脲原体检测呈阳性,占阳性患者总数的72%。解脲脲原体检测呈阳性患者的比例明显高于人型支原体检测呈阳性的患者比例,差异有统计学意义(χ^2=11.655,P=0.001<0.05)。对29例病原微生物检测呈阳性患者进行药敏试验,观察患者对常用抗生素药物的高敏、中敏以及耐药程度,其中支原体对强力霉素敏感性最高,对罗红霉素、司帕沙星、环酯红霉素、可乐必妥以及交沙霉素的敏感性较低。结论病原微生物检测与药敏试验能够有效明确慢性前列腺炎患者的病原体以及对于不同抗生素药物的敏感性,从而有利于临床上合理使用抗生素药物,值得临床推广和借鉴使用。     

The Second Generation CA125 Assays

Optimal management of ovarian cancer patients can only be provided using the CA 125 serum test for treatment monitoring, early prediction of outcome and early detection of recurrence. The newly introduced second generation CA 125 assays, the Centocor CA 125 II IRMA, the Boehringer Mannheim Enzymun CA 125 II and the BYK Liamat CA 125 II are one-step heterologous double-determinant solid phase assays that utilize the M11 as capture antibody and the original OC 125 as tracer. The CA 125 II assays will probably replace the original CA 125 assays within a short period of time. For comparison reasons the Abbott IMx CA 125 assay was also included in this study.

Highly similar CA 125 distribution patterns were obtained with these new CA 125 II assays. Linear regression analysis in ovarian cancer patients showed the following: Centocor CA 125 II = 0.98×CA 125 IRMA+ 10.7 (r = 0.8717, P<0.0001), Sy|x = 89.9; Enzymun CA 125 II = 1.03×CA 125 IRMA + 9.0 (r=0.8988, P<0.0001), Sy|x = 81.8; BYK Liamat CA 125 II = 1.17×CA 125 IRMA + 0.6 (r = 0.8930, P<0.0001), Sy|x = 96.8. Our first technical and clinical evaluation of these three new CA 125 II assays shows their superior analytical performance, in addition to a high qualitative and quantitative correlation with the original CA 125 IRMA.     

Detection of expanded-spectrum β-lactamases in Gram-negative bacteria in the 21st century

Emerging β-lactamase-producing-bacteria (ESBL, AmpC and carbapenemases) have become a serious problem in our community due to their startling spread worldwide and their ability to cause infections which are difficult to treat. Diagnosis of these β-lactamases is of clinical and epidemiological interest. Over the past 10 years, several methods have been developed aiming to rapidly detect these emerging enzymes, thus preventing their rapid spread. In this review, we describe the range of screening and detection methods (phenotypic, molecular and other) for detecting these β-lactamases but also whole genome sequencing as a tool for detecting the genes encoding these enzymes.     

近红外脉冲光乳腺疾病诊断系统功率谱和互相关曲线分析

目的 提出一种乳腺疾病无损检测新技术及其分析方法.方法 基于近红外脉冲光的乳腺疾病诊断系统软件部分以VC为开发工具,主要实现图像同步采集、图像配准、分析处理和数据管理等功能,其中分析处理部分包含感兴趣点分析和区域分析两种方法,点分析主要包含功率谱曲线、相关性曲线和相关系数,区域分析则是计算区域内所有点相关系数形成由相关系数构成的伪彩图像.文中对一例典型的乳腺癌患者做了详细的诊断分析.结果 乳腺癌患者病变部位的相关系数一般小于0.6,其功率谱呈现很多次频峰,互相关曲线上出现很多毛刺.而正常人的相关系数基本都在0.8以上,其功率谱和互相关曲线较光滑.结论 该系统具备非侵入、无辐射、廉价的特性,通过对典型病例的光强分析展示了系统的临床使用价值.     

DECAY RESISTANCE IN THE CYPRESS PINES

The resistance of the heartwood and sapwood of several species of the genus Callitris to attack by the brown rot fungus Coniophora olivacea has been compared. The heartwood of the three forms of C. columellaris, and also of C. macleayana proved to be highly resistant to attack. The heartwood of forms of C. preissii was resistant, and that of C. enderlicheri and C. rhomboides was moderately resistant to this fungus. The sapwood of all the species proved to be uniformly susceptible to attack by the fungus. On the basis of the decay resistance tests, the three forms of C. columellaris could not be distinguished.     

磷酸化肌球蛋白轻链在大鼠慢性移植肾肾病早期病变中的作用及其机制

目的 探讨磷酸化肌球蛋白轻链(pMLC)在慢性移植肾肾病(CAN)中的作用与机制.方法 依照标准的CAN大鼠模型进行左肾原位移植,受者为LEW大鼠,供者为F344大鼠,另取雄性F344大鼠和LEW大鼠仅行单肾切除术,分别作为对照.分别于术后4、8及12周时,收集各组大鼠的24 h尿量,并检测其尿肌酐水平,计算肌酐清除率.然后取各组大鼠血液标本,测定血清肌酐水平.采用Banff分级标准评定各组肾小球肾病、肾小管萎缩、间质纤维化及血管内膜增厚程度.采用免疫组织化学法和采用蛋白质印迹法检测肾组织中磷酸化MLC(pMLC)和整合素连接激酶(ILK)的表达部位及表达水平.结果 移植组大鼠术后4周时肾间质可见单个核细胞浸润,12周时可见血管平滑肌细胞的移行与增殖.移植组大鼠各时相肾组织pMLC和ILK表达水平显著高于Lewis对照组及F344对照组,且随着移植时间的延长有逐渐增高趋势.大鼠移植肾组织中pMLC表达水平与24 h尿蛋白定量、血清肌酐水平、肾间质单个核细胞浸润、肾小动脉血管平滑肌细胞数量、Banff评分等呈显著正相关,相关系数(r)分别为0.273(P＜0.05)、0.434(P＜0.01)、0.525(P＜0.01)、0.676(P＜0.01)、0.570(P＜0.01),在移植后4周时,pMLC表达水平与肾小管间质ILK表达水平呈显著正相关,r=0.778(P＜0.01).结论 pMLC在慢性移植肾病早期病理变化中发挥重要作用,移植肾肾小管间质及肾小动脉中pMLC表达上调与ILK的作用机制相关.

Abstract：

Objective To investigate the role and mechanism of phosphate myosin light chain (pMLC) in the rat kidney of chronic allograft nephropathy (CAN) model. Methods The left donor kidneys from Fisher (F344) rats were orthotopically transplanted into Lewis recipients. Meanwhile, the F344 rats and LEW rats with resection of the right kidney served as control groups. Animals were harvested respectively at the 4th, 8th and 12th week after transplantation. The creatinine clearance rate (CCr) was calculated by urine creatinine of 24-h urine. Blood samples were collected from rats for determination of serum creatinine. The expression of pMLC was detected by using Western blotting and immunohistochernistry, and that of integrin-linked kinase (ILK) by using immunohistochemistry. Results Mononuclear cells infiltration of allografts was markedly aggravated as compared to the controls. Allografts got severe interstitial fibrosis and tubular atrophy at 12th week after transplantation. The expression of pMILC and ILK was up-regulated in the kidney of CAN rats after transplantation, and increased more significantly as the time went on. The expression of pMILC was significantly correlated with 24-h urine protein excretion (r= 0. 273, P＜0. 05), serum creatinine levels (r = 0. 434, P＜0. 01 ), the number of tubulointerstitial infiltrated mononuclear cells (r = 0. 525, P＜0. 01 ), the number of smooth muscle cells (SMC) in vascular wall (r= 0. 676, P＜0. 01 ) and the extent of interstitial fibrosis (r= 0. 570, P＜0. 01 ).There was a significantly positive correlation between ILK and pMLC in CAN rats at the 4th week after transplantation (r= 0. 778, P＜0. 01 ). Conclusion pMLC might play an key role in CAN, and the over-expression of ILK might be involve in the pathogenesis of CAN.