光敏剂浓度和给药时间对荧光诊断效果的影响

目的 为探索光敏剂浓度和给药时间对蓝光诱导的荧光诊断的影响,以提高荧光诊断的准确度.方法 常规方法制备荷瘤小鼠,分别给荷瘤小鼠静脉注射不同浓度（0～70 mg/kg体质量）的光敏剂-血卟啉衍生物（HpD）,并在给药后不同时间（0～48 h）,以前置395～415 nm滤光片的碘镓灯为激发光源,蓝光诱导载体荧光,通过图像采集系统采集荧光图像,取活组织做病理切片检查.结果 HpD浓度为40mg/kg体质量,给药后18 h,可以较为精确地反映肿瘤组织的浸润范围,荧光诊断准确度高于其他实验组;同时假阳性率低于其它实验组,差异有统计学意义.结论 荧光诊断的效果与光敏剂的浓度和观察时间密切相关;优化2者参数,可提高荧光诊断的准确度并降低假阳性率,对临床肿瘤手术方案的制定有重要参考价值.     

基于人眼视觉特性的图像处理技术

本文根据视觉神经的感知特性和Weber-Fechner定理,提出了新的中值滤波和图像增强等图像处理方法,有效地改善了细胞显微图像的质量,使之更加符合人眼的观察特性,同时为图像处理技术提供了新的手段和思路。     

光动力疗法的抗肿瘤机制及光敏剂的研究进展

光动力疗法（PDT）是利用光动力效应对疾病进行诊断与治疗的一种非侵袭性技术,已被用于临床头颈部、乳腺、肺、前列腺及皮肤等部位肿瘤的治疗.与传统治疗方法相比,PDT具有创伤小、毒性低、选择性好、适用范围广及不易产生耐药等优势,因而受到肿瘤治疗领域的广泛关注.PDT的抗肿瘤机制复杂,光敏剂是发挥其光动力学效应的关键因素之一,提高光敏剂的靶向输送和携氧能力是改善光动力疗效的重要途径.对PDT的抗肿瘤机制及光敏剂的研究进展进行综述.     

基于MATLAB视网膜视锥细胞的图像处理

背景：视网膜自适应光学成像系统所获取的视锥细胞图像具有灰度分布相对集中、亮点边缘比较模糊、存在伪轮廓及边缘相粘连的特点,寻找一种适合视锥细胞图像的处理算法来获取视网膜视锥细胞清晰轮廓成为今后工作的重点内容。 目的：采用MATLAB图像处理工具箱对视锥细胞图像进行边缘提取,获取其清晰的边缘轮廓。 方法：对30例正常受试者不同部位视锥细胞图像进行预处理、边缘提取和形态学处理,获取视锥细胞图像清晰的边缘轮廓;对处理后的图像进行细胞计数,并分析视锥细胞密度分布特性,进而来验证图像处理算法应用于视锥细胞分布特性研究的可行性。 结果与结论：获取了清晰的视网膜视锥细胞图像轮廓;从结果来看,随着远离黄斑中心凹,细胞密度呈现出降低的趋势,从黄斑中心凹偏0.5°到1°范围内,视网膜视锥细胞密度下降最快。结果提示：实验所设计的图像处理算法在研究视网膜视锥细胞分布特性方面是可行的。     

新型光敏剂治疗敏感及耐药胃癌的实验研究

目的 探讨一种新型光敏剂DTP对敏感胃癌细胞(SGC7901)及长春新碱耐药胃癌细胞(SGC7901/VCR)的光动力学治疗作用.方法 采用荧光显微镜间接确认SGC7901及SGC7901/VCR细胞膜上P-糖蛋白(P-gp)的表达情况,细胞计数试剂盒(CCK-8)检测DTP对SGC7901及SGC7901/VCR细胞的光动力学杀伤作用,荧光分光光度计测定两种细胞内的DTP吸收量,激光共聚焦显微镜观察DTP在两种细胞内的分布位置.结果 SGC7901细胞膜上几乎无P-gp分布,而SGC7901/VCR细胞膜上存在P-gp高表达.新型光敏剂DTP对SGC7901及SGC7901/VCR细胞均具有较强的光动力学杀伤作用,其中对SGC7901/VCR细胞的作用相对较弱(P＜0.05),且P-gp抑制剂维拉帕米或环孢素A的存在均不能增强DTP光动力学治疗对SGC7901/VCR细胞的杀伤作用(均P＞0.05).SGC7901细胞内的DTP吸收量高于SGC7901/VCR细胞(P＜0.05),且P-gp抑制剂维拉帕米和环孢素A均不能增加SGC7901/VCR细胞内的DTP吸收量(均P＞0.05).DTP分布于SG-C7901细胞的溶酶体以及SGC7901/VCR细胞的溶酶体和线粒体内.结论 新型光敏剂DTP并非多药转运蛋白P-gp的底物,其对SGC7901/VCR细胞较弱的光动力学杀伤作用与其细胞膜上过表达的P-gp无关,可能与DTP在两种细胞内的分布位置不同有关.     

基于图像处理技术的微生物鉴定系统酶标板正反检测方法研究

通过考察典型酶标板的特征及其图像拍摄条件,截取一局部子图像,基于孔心定位对其进行二次分割获得标号字符图像,经直方图均衡化增强处理后,将其与正反模板图像进行模板匹配,计算相关匹配系数,实现正反方向检测。以203张酶标板图像验证,放置方向检测正确率可达到100%。     

包裹光敏剂m—THPC的PLGA微球的体外释放特性研究

目的:测量包裹光敏剂m-THPC的PLGA微球的载药量,并定量分析在含不同浓度脂肪乳和血清的水溶液中PLGA微球的体外释放规律.方法:称取一定质量PLGA微球,置入一定体积的二氯甲烷和甲醇混合有机溶剂中完全溶解,测量溶液荧光强度,与荧光强度一光敏剂m-THPC浓度标准曲线对比得出光敏剂m-THPC的浓度后计算出PLGA微球的载药量;称取一定质量的载药量已知的PLGA微球,置入200mL含脂肪乳和血清的水溶液中释放,37℃恒温摇床摇动,每次取样0.5 mL,测量溶液荧光强度,与荧光强度-光敏剂m-THPC浓度标准曲线对比得出光敏剂m-THPC的浓度后计算出光敏剂m-THPC的释放量.结果:血清能加速PLGA微球的释放,同时脂肪乳浓度越高,PLGA微球释放光敏剂m-THPC的速度越快.结论:给病人注射适量的脂肪乳注射液,有可能提高PLGA微球释放速度和光敏剂m-THPC在血液中的浓度,从而提高光动力治疗效率.     

毛细血管到毛细淋巴管物质通透过程的活体定量分析

本文利用荧光生物显微电视系统和计算机图像处理技术定量分析了大白鼠肠系膜微循环中荧光物质从毛细血管经组织间质,到毛细淋巴管的物质移动的动态过程,测出了在整个传输过程中,毛细血管、组织和毛细淋巴管三个不同部位中,由荧光物质浓度变化引起的实时辉度变化曲线,进行了物质通透过程的基础性研究。研究证明了淋巴循环在循环中的重要辅助作用,毛细淋巴管的通透与淋巴管自身的收缩运动的密切的关系。     

基于图像处理的菌落自动计数系统

目的针对现有菌落计数仪结构复杂、便携性差等缺点,本文设计了一种基于图像处理技术和Android平台来完成菌落自动计数的系统。方法该系统由硬件拍照设备采集菌落图像,以智能手机为主要操作载体,对图像进行光谱阈值分割、中值滤波、洪水填充、开值运算、八邻域边界跟踪等多种算法处理后实现自动计数。结果与菌落计数仪相比,该系统使用移动端手机APP实时获取菌落图像并得到计数结果,可直接在手机上对结果进行手动校正,具有成本低、操作简单、便携性好等优点。结论基于图像处理的菌落自动计数系统与人工计数结果的相对误差不超过5%,满足菌落计数的要求。     

Quantification of chromatin condensation level by image processing

The level of chromatin condensation is related to the silencing/activation of chromosomal territories and therefore impacts on gene expression. Chromatin condensation changes during cell cycle, progression and differentiation, and is influenced by various physicochemical and epigenetic factors.This study describes a validated experimental technique to quantify chromatin condensation. A novel image processing procedure is developed using Sobel edge detection to quantify the level of chromatin condensation from nuclei images taken by confocal microscopy. The algorithm was developed in MATLAB and used to quantify different levels of chromatin condensation in chondrocyte nuclei achieved through alteration in osmotic pressure. The resulting chromatin condensation parameter (CCP) is in good agreement with independent multi-observer qualitative visual assessment. This image processing technique thereby provides a validated unbiased parameter for rapid and highly reproducible quantification of the level of chromatin condensation.     

Melanomas non-invasive diagnosis application based on the ABCD rule and pattern recognition image processing algorithms

In this paper an automated dermatological tool for the parameterization of melanomas is presented. The system is based on the standard ABCD Rule and dermatological Pattern Recognition protocols. On the one hand, a complete stack of algorithms for the asymmetry, border, color, and diameter parameterization were developed. On the other hand, three automatic algorithms for digital image processing have been developed in order to detect the appropriate patterns. These allow one to calculate certain quantitative features based on the aspect and inner patterns of the melanoma using simple-operation algorithms, in order to minimize response time. The database used consists of 160 500×500-pixel RGB images (20 images per pattern) cataloged by dermatologists, and the results have turned out to be successful according to assessment by medical experts. While the ABCD algorithms are mathematically reliable, the proposed algorithms for pattern recognition produced a remarkable rate of globular, reticular, and blue veil Pattern recognition, with an average above 85% of accuracy. It thus proves to be a reliable system when performing a diagnosis.     

Study and performance evaluation of statistical methods in image processing

Two statistical image processing formalisms involving the entropy concept and Bayesian analysis are studied. Iterative imaging algorithms of the formalisms are formulated by employing, for the purpose of performance evaluation and easy implementation, the steepet descent method for the solution of entropy concept and the expectation maximization technique for the solution of Bayesian analysis. Quantitative evaluation and comparison of the convergence performance of the iterative algorithms on computer generated ideal and experimental radioisotope phantom imaging noisy data are given. The study concludes that the entropy algorithm can converge relatively fast, but it is very sensitive to noise in measured data due to the ill-posed nature of inverse problems and its lack of ability to consider the statistics of data and has the advantage of Bayesian algorithm converges monotonically even with noisy data and has the advantage of considering both the a priori source distribution information and the statistical fluctuation of measured data.     

Integer filters for image processing

In the paper Lynn's fast integer filtering methods are extended to two-dimensional image processing applications. Examples are included which verify the speed and the quality of the filtering for various types of filters. Initial condition requirements for one-dimensional integer filters are also extended to the two-dimensional case.     

An attempt to analyze locomotion of leukemia cells by computer image processing

Phase contrast photographs of locomotive leukemia cells from a time lapse film were analyzed by an image processing computer system. Various structural and directional parameters were chosen to characterize dislocation and shape changes of a moving cell. A correlation could be established between the cellular image seen in time lapse films and the numerical shape configuration based on automated image analysis. It seems, therefore, that the parameters chosen represent a basis for further evaluation of the quantitative model of cellular locomotion.     

Distribution mapping of ciliary beat frequencies of respiratory epithelium cells using image processing

Through their rapid periodic actions, the cilia of the human respiratory tract play an important role in clearing inhaled noxious particles. An automated method is developed, based on an image-processing technique, to measure and analyse objectively and quantitatively, ciliary beat frequency (CBF). Microscopic ciliary images are transformed into digitised grey images through an image grabber inside a PC, and signals are extracted from these, based on an image-subtraction algorithm, and are processed through power spectrum analysis using a fast Fourier transform (FFT). By means of the FFT power spectrum, maximum peak frequencies are detected as CBFs in each partitioned block for the entire digitised field. Using these CBFs, distribution maps are composed in various resolutions, showing visually the spatial distribution of CBFs through cells and in a single cell. To measure CBF variations quantitatively, phenylephrine hydrochloride is used, and the changes in CBF influenced by its concentration and duration are observed.     

基于影像学及计算机图像处理方法研究活体腰椎小关节结构三维分布

目的基于小关节三维重建图像分析软骨下皮质骨厚度、小关节面面积及关节间隙宽度的三维分布情况,研究其结构特点及变化规律,并比较腰痛患者及健康人中这些参数的差别。方法对90名研究对象分别行仰卧位CT扫描,获取L1～S1 5个节段小关节的二维图像,重建后分别获得软骨下皮质骨、小关节面及关节间隙的三维面点云图。研究上述参数在整个关节面上、以及关节面的不同区域的分布特点,比较它们在不同腰椎节段、性别、年龄及症状组中的差异。结果 (1)软骨下皮质骨厚度方面,在上关节突,头端区最厚;在下关节突,尾端区最厚。中央区的厚度明显小于其他各区。各区之间的差别在低位节段腰椎中(L4/5,L5/S1)较明显。(2)小关节平均面积为(173.2±3.6)mm2,且随腰椎节段及年龄的增加而增大,L4/5节段以下及40岁以上更加明显。腰痛患者上关节突关节面的面积明显较下关节突关节面的面积大(L5/S1节段除外)。腰痛患者的小关节面积明显大于健康人。(3)小关节间隙平均宽度为(1.46±0.08)mm,随年龄增加而变窄,40岁以上者更明显,女性均较男性宽,腰痛患者则显著变窄。分区比较时,关节面头侧关节间隙较尾侧间隙宽,中央区的间隙普遍较周围区宽,这些差别在腰痛患者及下3个节段中更明显。结论计算机图像处理及重建分析技术可以较准确的测量三维空间内形状复杂的小关节的相关参数。小关节各结构在三维空间的分布具有一定特点,这些特点与关节面形态、关节间应力及关节退变等因素有关,反映了长期的负荷状态下人体结构的适应性改变。     

An image processing software applied to oral pathology

This study presents the development and evaluation of an image processing software for computer-assisted cellular structure counting. The proposed software consists of a set of processing and analytical tools which allows its use in several applications of cell and cellular structure counting. A particular application in AgNOR quantitative analysis is presented. The knowledge obtained from experienced pathologists has been codified in a sequence of processing steps in order to allow automatic estimation of the mean number of AgNORs per cell in ameloblastomas. The performance of the presented software in such application was verified by comparing the data provided by visual analysis, by two observers previously calibrated and under supervision of two experienced specialists (Group 1) and by the computer program (Group 2). No statistical difference was observed (p < 0.05) between the two groups. The use of the proposed method in AgNOR applications permitted attainment of accurate and precise data without the difficulties frequently found in the traditional visual analysis method (time, training and subjectivity). The developed software is an interesting tool as an aid in the study (estimation of the number of cells and cellular structures) of malignant and benign neoplasms.