Aβ1-42注射后大鼠海马神经元凋亡及线粒体凋亡途径相关蛋白表达变化的研究

目的:研究大鼠海马注射淀粉样β蛋白(β-amyloid,Aβ)后海马神经元凋亡及线粒体凋亡途径相关蛋白表达的变化,探讨其在阿尔茨海默病发病机制与病理改变中的作用.方法:SD大鼠36只随机分为正常对照组,生理盐水组和模型组.大鼠双侧海马注射Aβ1-42越建立AD模型,不同时间点Y迷宫进行行为学测试,TUNEL法检测海马神经元凋亡表达,western-blot检测海马细胞色素C、caspase-9蛋白表达.结果:模型组大鼠术后14天达到学会标准所需电击次数较生理盐水组和正常对照组增加(P<0.05),21天、28天增加更显著(P<0.01).模型组凋亡细胞数较正常对照组、生理盐水组明显增多(P<0.01).模型组大鼠海马细胞色素C与caspase-9蛋白表达明显高于生理盐水组与正常对照组(P<0.05).结论:Aβ1-42>海马注射通过激活线粒体凋亡途径诱导海马神经元凋亡.引起大鼠学习记忆能力损害,在AD的发病机制与病理进程中发挥重要作用.     

妊娠期高血压疾病大鼠肾脏中蛋白激酶C-a亚型蛋白表达和转录水平的变化

目的:通过研究PKC-a蛋白及mRNA转录表达水平在妊娠期高血压疾病大鼠肾脏中的变化,以探讨妊娠期高血压疾病肾脏病理生理变化发生的机制.方法:注射L-NAME方法制备妊娠期高血压疾病动物模型并应用Westem印迹杂交及RT-PCR半定量方法检测15例妊娠期高血压疾病大鼠、正常妊娠大鼠、健康孕龄大鼠肾脏组织PKC-α亚型的表达情况.结果:妊娠期高血压疾病大鼠肾脏组织中PKC-α的蛋白及mRNA表达水平显著高于正常妊娠组(P<0.01),正常妊娠大鼠肾脏PKC-α的蛋白及mRNA表达水平明显低于对照组大鼠(P<0.01).结论:妊娠期高血压疾病大鼠肾脏组织中存在PKC-α的蛋白及mRNA的过度表达,它可能参与妊娠期高血压疾病肾脏病理生理变化.     

慢性阻塞性肺病大鼠模型的建立和比较评估

目的:动态观察运用不同方法建立的两种实验性大鼠慢性阻塞性肺疾病(COPD)模型并比较评估两组模型的特点.方法:分别采用单纯被动吸烟(单一组)和被动吸烟与细菌内毒素(LPS)气管注入的复合方法(复合组)制造大鼠COPD模型,运用HE染色及半定量图像分析法对比研究两组模型肺组织及小支气管的病理形态学改变.结果:建立的COPD大鼠模型均符合人类COPD的病理形态学特点;复合组的气道慢性炎症、重塑改变及气流阻塞情况均较单一组严重;单一组、复合组模型各时间段管壁及平滑肌层均较正常对照组显著增厚(P＜0.01),第20天时复合组管壁及平滑肌层均较单一组显著增厚(P＜0.01),而第40天及60天时复合组仅管壁较单一组显著增厚(P＜0.01).结论:COPD模型的形成是由于慢性气道炎症的反复刺激引起管壁纤维性增生增厚及平滑肌层增厚,即气道重塑,最终导致气流受限;复合组COPD模型的气道炎症及气道重塑均较单一组COPD模型显著.     

逍遥散对慢性束缚应激模型大鼠相关脑区CRF基因表达的影响

目的:观察慢性束缚应激大鼠相关脑区CRF mRNA(下丘脑、垂体、海马、皮层)含量变化以及逍遥散对其影响.方法:用RT-PCR和图像分析方法测定相关脑区CRF mRNA含量变化.结果:应激组较正常对照组在下丘脑CRF-1基因表达下调(P<0.01).在下丘脑逍遥散组较应激组CRF-1基因表达显著下调(P<0.01),CRF-2基因表达显著上调(P<0.01);在海马区逍遥散组CRF-2基因表达较模型组上调(P<0.05);在皮层逍遥散组CRF-1基因表达较应激组则显著上调(P<0.01).结论:逍遥散组对慢性束缚应激中枢神经肽CRF的调节位点在下丘脑、垂体、海马和皮层,充分证实逍遥散的调节靶点与下丘脑、边缘系统及皮层中枢有关.     

骨髓间充质干细胞对大鼠急性肾损伤的修复作用

目的:观察外源性骨髓间充质干细胞(Mesenchymal stem cells,MSCs)对庆大霉素(Gentamycin,GM)诱导的大鼠急性肾损伤是否具有治疗作用,并初探其机制。方法:建立腹腔注射庆大霉素致大鼠急性肾损伤模型实验分为正常对照组、模型组、MSCs治疗组(模型+MSCs)、生理盐水组(模型+生理盐水)。于不同处理后4d分别检测血尿素氮(BUN)和肌酐(Scr)水平,观察肾组织病理改变,免疫印迹及RT-PCR法检测肾组织肝细胞生长因子(Hepatocyte growth factor,HGF)水平。结果:模型组大鼠的BUN及Scr较正常对照组显著升高,且肾小管组织病理损伤严重;而MSCs治疗组大鼠的BUN及Scr水平较生理盐水组显著降低,肾小管组织病理损伤明显减轻。此外,促肾小管损伤修复的肝细胞生长因子(HGF)表达在MSCs治疗组显著高于生理盐水组。结论:MSCs输注可促进庆大霉素所致急性肾小管损伤的修复,改善肾功能,其作用机制可能是与上调肾组织中肝细胞细胞生长因子的表达有关。     

胎儿生长受限模型及其胎盘的病理学观察

目的证实胎儿生长受限大鼠模型的建立方法;观察胎儿生长受限(FGR)大鼠胎盘的组织形态及超微结构特征。方法健康Wistar雌鼠24只,按妊娠先后顺序随机分为两组:正常对照组(正常组)、模型组(烟酒处理组),采用烟酒混合因素建立大鼠FGR模型;比较两组胎鼠的体重、鼻臀长度、体重系数及FGR发生率,两组胎盘组织行HE染色,并应用光镜和电镜观察其病理变化。结果①模型组胎仔平均体重、鼻臀长度、体重系数较正常组分别减轻46.0%、21.9%、35.0%(P0.01)。对照组FGR发生率仅为12.5%,模型组FGR发生率为79.3%,显著高于对照组(P0.01)。②模型组胎盘形态学明显改变。结论通过烟酒干预的方法,成功建立缺血缺氧性FGR孕鼠模型。烟酒可导致胎盘形态结构的改变,这种病理改变是造成FGR胎盘功能减退的形态学基础。     

肺虚痰阻证模型大鼠肺组织水通道蛋白1 和5 分子表达与补肺化痰方对 其影响*

目的:1)从肺泡上皮水主动转运功能的角度探讨肺虚痰阻证的发生机理。2)通过观察肺虚痰阻证模型的AQP的活性及其相关基因、蛋白的表达和补肺化痰中药复方治疗前、后的对比,观察这一过程中上述指标的变化情况。方法:将雄性SD大鼠随机分为正常组、模型组、中药治疗组。模型组和治疗组造模40天,治疗组在造模26天后,药物灌胃治疗2周。采用组织化学染色法,对大鼠肺进行病理分析;RT-PCR的方法检测大鼠肺组织中AQP1、AQP5基因表达;western blot法检测大鼠肺组织中AQP1、AQP5蛋白水平。结果:1)与正常组相比,模型组局部出现明显炎症反应(P<0.01),治疗组局部炎症反应减轻(P<0.05)。2)mRNA结果显示,AQP1在正常组有表达,在模型组和治疗组未见表达。AQP5模型组与正常组相比,表达量显著增高(P<0.01);治疗组与模型组比较,表达量显著降低(P<0.01),但与正常组无显著差异。3)蛋白水平上,AQP1在模型组和治疗组与正常组相比差异显著(P<0.05),表达下降。AQP5模型组与正常组相比,显著升高(P<0.01);治疗组与模型组比较,显著下调(P<0.05);正常组表达低于治疗组,差异显著(P<0.05)。结论:1)AQP1和5基因及蛋白表达量变化是肺虚痰阻证的病理机制之一。2)补肺化痰中药复方可调节肺虚痰阻证模型大鼠肺组织AQP 5基因及蛋白表达。提示补肺化痰中药复方治疗肺虚痰阻证其作用机制与调节AQP5有关。     

藏红花抗大鼠肝纤维化的实验研究

目的:观察藏红花对实验性大鼠肝纤维化的防治效果,探讨其作用机制.方法:将清洁级雄性大鼠60只随机分为正常对照组、模型对照组、复方丹参组、藏红花组.除正常对照组外,其余3组均予四氯化碳腹腔注射,复方丹参组、藏红花组分别予复方丹参、藏红花溶液灌胃,第8周末处死动物,用放射免疫法检测血清透明质酸、层粘连蛋白、Ⅲ型前胶原和Ⅳ型胶原.肝组织切片HE、MASSON染色,显微镜下观察结果.结果:藏红花组大鼠肝纤维化病理改变较轻,血清透明质酸、层粘连蛋白、Ⅲ型前胶原和Ⅳ型胶原水平下降,与模型对照组差异显著(P<0.05).结论:藏红花具有减少肝纤维化大鼠的胶原沉积,抗肝纤维维化作用.     

散发性阿尔茨海默病大鼠学习记忆和抗氧化能力的观察

目的:观察散发性阿尔茨海默病动物模型的学习记忆和抗氧化能力,初步探讨该疾病的发生机制。方法:雄性SD大鼠24只,随机分为正常对照组和模型组。模型组大鼠给予侧脑室注射STZ制作散发性阿尔茨海默病动物模型,3周后,通过Morris水迷宫方法进行行为学检测,生物化学方法检测海马超氧化物歧化酶(SOD)活力、丙二醛(MDA)含量的变化。结果:与对照组比较,模型组大鼠潜逃潜伏期延长(P<0.05)、目的象限停留时间显著降低(P<0.05);海马SOD活力降低(P<0.01),MDA含量增加(P<0.01)。结论:散发性阿尔茨海默病大鼠学习记忆能力低,其发生机制可能与大鼠海马的抗氧化能力下降有关。     

白介素-18在被动吸烟诱导的慢性阻塞性肺疾病大鼠中的表达

目的 研究白介紊-18(Interleukin-18,IL-18)在被动吸烟诱导的慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)大鼠中的表达变化.方法 将20只大鼠随机分为2组,即正常对照组和COPD模型组.应用单纯被动吸烟法建立大鼠COPD模型,香烟烟雾暴露时间为6个月.利用酶联免疫吸附法测定2组大鼠血清和支气管肺泡灌洗液(bronchoal veolar lavage fluid,BALF)中的IL-18浓度,用实时定量RT-PCR法测定BALF中IL-18 mRNA的表达水平,用HE染色法观察肺组织形态学改变,用免疫组织化学染色法检测IL-18在肺组织中的表达.结果 1.COPD模型组血清和BALF中的IL-18浓度较正常对照组显著增加(P＜0.01);2.COPD模型组BALF中IL-18 mRNA的表达水平较正常对照组显著增高(P＜0.01);3.COPD模型组肺组织中IL-18的表达较正常对照组显著增加(P＜0.01).结论 被动吸烟诱导的COPD大鼠外周血和肺部均高表达IL-18,提示IL-18在吸烟所致的COPD发病机制中可能起重要作用.     

用组织光学特性鉴别诊断人离体的正常膀胱和膀胱癌组织

研究正常人膀胱和膀胱癌组织在Kube lka-Munk二流模型下对476.5 nm,514.5 nm和808 nm波长的激光的光学特性的差异。采用双积分球系统和Kube lka-Munk二流模型进行测量研究。实验结果表明,正常膀胱和膀胱癌组织在Kube lka-Munk二流模型下对476.5 nm,514.5 nm和808 nm波长的每一个波长的激光的吸收、散射、总衰减、有效衰减系数都有非常显著性的差异(P<0.01)。膀胱癌组织对476.5 nm,514.5 nm和808nm波长的激光的吸收系数明显地较正常膀胱组织对相应波长的激光的吸收系数要大(P<0.01),膀胱癌组织对476.5 nm和514.5 nm波长的激光的散射系数明显地较正常膀胱组织对相应波长的激光的散射系数要小(P<0.01),而膀胱癌组织对808 nm波长的激光的散射系数明显地较正常膀胱组织对同一波长的激光的散射系数要大(P<0.01)。膀胱癌组织对476.5 nm,514.5 nm和808 nm波长的激光的总衰减系数明显地较正常膀胱组织对相应波长的激光的总衰减系数要大(P<0.01),膀胱癌组织对476.5 nm,514.5 nm和808 nm波长的激光的有效衰减系数明显地较正常膀胱组织对相应波长的激光的有效衰减系数要大(P<0.01)。提示使用双积分球系统和Kube lka-Munk二流模型来确定离体的正常膀胱组织和膀胱癌组织对476.5 nm,514.5 nm和808nm波长的激光的光学特性的差异鉴别诊断病变的膀胱组织是一个有效的方法。     

One‐to‐one registration of en‐face optical coherence tomography attenuation coefficients with histology of a prostatectomy specimen

Optical coherence tomography (OCT), enables high‐resolution 3D imaging of the morphology of light scattering tissues. From the OCT signal, parameters can be extracted and related to tissue structures. One of the quantitative parameters is the attenuation coefficient; the rate at which the intensity of detected light decays in depth. To couple the quantitative parameters with the histology one‐to‐one registration is needed. The primary aim of this study is to validate a registration method of quantitative OCT parameters to histological tissue outcome through one‐to‐one registration of OCT with histology. We matched OCT images of unstained fixated prostate tissue slices with corresponding histology slides, wherein different histologic types were demarcated. Attenuation coefficients were determined by a supervised automated exponential fit (corrected for point spread function and sensitivity roll‐off related signal losses) over a depth of 0.32 mm starting from 0.10 mm below the automatically detected tissue edge. Finally, the attenuation coefficients corresponding to the different tissue types of the prostate were compared. From the attenuation coefficients, we produced the squared relative residue and goodness‐of‐fit metric R². This article explains the method to perform supervised automated quantitative analysis of OCT data, and the one‐to‐one registration of OCT extracted quantitative data with histopathological outcomes.      

Pilot feasibility study of in vivo intraoperative quantitative optical coherence tomography of human brain tissue during glioma resection

This study investigates the feasibility of in vivo quantitative optical coherence tomography (OCT) of human brain tissue during glioma resection surgery in six patients. High‐resolution detection of glioma tissue may allow precise and thorough tumor resection while preserving functional brain areas, and improving overall survival. In this study, in vivo 3D OCT datasets were collected during standard surgical procedure, before and after partial resection of the tumor, both from glioma tissue and normal parenchyma. Subsequently, the attenuation coefficient was extracted from the OCT datasets using an automated and validated algorithm. The cortical measurements yield a mean attenuation coefficient of 3.8 ± 1.2 mm^?1 for normal brain tissue and 3.6 ± 1.1 mm^?1 for glioma tissue. The subcortical measurements yield a mean attenuation coefficient of 5.7 ± 2.1 and 4.5 ± 1.6 mm^?1 for, respectively, normal brain tissue and glioma. Although the results are inconclusive with respect to trends in attenuation coefficient between normal and glioma tissue due to the small sample size, the results are in the range of previously reported values. Therefore, we conclude that the proposed method for quantitative in vivo OCT of human brain tissue is feasible during glioma resection surgery.     

Characterization of the human myocardium by optical coherence tomography

Imaging of cardiac tissue structure plays a critical role in the treatment and understanding of cardiovascular disease. Optical coherence tomography (OCT) offers the potential to provide valuable, high‐resolution imaging of cardiac tissue. However, there is a lack of comprehensive OCT imaging data of the human heart, which could improve identification of structural substrates underlying cardiac abnormalities. The objective of this study was to provide qualitative and quantitative analysis of OCT image features throughout the human heart. Fifty human hearts were acquired, and tissues from all chambers were imaged with OCT. Histology was obtained to verify tissue composition. Statistical differences between OCT image features corresponding to different tissue types and chambers were estimated using analysis of variance. OCT imaging provided features that were able to distinguish structures such as thickened collagen, as well as adipose tissue and fibrotic myocardium. Statistically significant differences were found between atria and ventricles in attenuation coefficient, and between adipose and all other tissue types. This study provides an overview of OCT image features throughout the human heart, which can be used for guiding future applications such as OCT‐integrated catheter‐based treatments or ex vivo investigation of structural substrates.     

General model for depth‐resolved estimation of the optical attenuation coefficients in optical coherence tomography

We present the proof of concept of a general model that uses the tissue sample transmittance as input to estimate the depth‐resolved attenuation coefficient of tissue samples using optical coherence tomography (OCT). This method allows us to obtain an image of tissue optical properties instead of intensity contrast, guiding diagnosis and tissues differentiation, extending its application from thick to thin samples. The performance of our method was simulated and tested with the assistance of a home built single‐layered and multilayered phantoms (~100 μm each layer) with known attenuation coefficient on the range of 0.9 to 2.32 mm^?1. It is shown that the estimated depth‐resolved attenuation coefficient recovers the reference values, measured by using an integrating sphere followed by the inverse adding doubling processing technique. That was corroborated for all situations when the correct transmittance value is used with an average difference of 7%. Finally, we applied the proposed method to estimate the depth‐resolved attenuation coefficient for a thin biological sample, demonstrating the ability of our method on real OCT images.     

Imaging atherosclerotic plaque composition with intracoronary optical coherence tomography

Optical coherence tomography (OCT) allows highly accurate diagnosis of atherosclerotic plaques, including measurement of the thickness of fibrous caps, permitting an assessment of the risk of rupture. While the OCT image presents morphological information in highly resolved detail, it relies on interpretation by trained readers for the identification of tissue type. We developed a method for quantitative classification of atherosclerotic plaque constituents. The optical attenuation coefficient μ_t distinguishes different tissue types: necrotic core and macrophage infiltration exhibit strong attenuation, μ_t≥10 mm⁻¹, while calcific and fibrous tissue have a lower μ_t≈2–5 mm⁻¹. (Neth Heart J 2009;17:448-50.)     

Characterizing biochemical and morphological variations of clinically relevant anatomical locations of oral tissue in vivo with hybrid Raman spectroscopy and optical coherence tomography technique

This study aims to characterize biochemical and morphological variations of the clinically relevant anatomical locations of in vivo oral tissue (ie, alveolar process, lateral tongue and floor of the mouth) by using hybrid Raman spectroscopy (RS) and optical coherence tomography (OCT) technique. A total of 1049 in vivo fingerprint (FP: 800‐1800 cm^?1) and high wavenumber (HW: 2800‐3600 cm^?1) Raman spectra were acquired from different oral tissue (alveolar process = 331, lateral tongue = 339 and floor of mouth = 379) of 26 normal subjects in the oral cavity under the OCT imaging guidance. The total Raman dataset were split into 2 parts: 80% for training and 20% for testing. Tissue optical attenuation coefficients of alveolar process, lateral tongue and the floor of the mouth were derived from OCT images, revealing the inter‐anatomical morphological differences; while RS uncovers subtle FP/HW Raman spectral differences among different oral tissues that can be attributed to the differences in inter‐ and intra‐cellular proteins, lipids, DNA and water structures and conformations, enlightening biochemical variability of different oral tissues at the molecular level. Partial least squares‐discriminant analysis implemented on the training dataset show that the integrated tissue optical attenuation coefficients and FP/HW Raman spectra provide diagnostic sensitivities of 99.6%, 82.3%, 50.2%, and specificities of 97.0%, 75.1%, 92.1%, respectively, which are superior to using either RS (sensitivities of 90.2%, 77.5%, 48.8%, and specificities of 95.8%, 72.1%, 88.8%) or optical attenuation coefficients derived from OCT (sensitivities of 75.0%, 78.2%, 47.2%, and specificities of 96.2%, 67.7%, 85.0%) for the differentiation among alveolar process, lateral tongue and the floor of the mouth. Furthermore, the diagnostic algorithms applied to the independent testing dataset based on hybrid RS‐OCT technique gives predictive diagnostic sensitivities of 100%, 76.5%, 51.3%, and specificities of 95.1%, 77.6%, 89.6%, respectively, for the classifications among alveolar process, lateral tongue and the floor of the mouth, which performs much better than either RS or optical attenuation coefficient derived from OCT imaging. This work suggests that inter‐anatomical morphological and biochemical variability are significant which should be considered as an important parameter in the interpretation and rendering of hybrid RS‐OCT technique for oral tissue diagnosis and characterization.      

Investigation of the permeability and optical clearing ability of different analytes in human normal and cancerous breast tissues by spectral domain OCT

The potential of OCT applied for early breast cancer detection attracted significant efforts. The permeability coefficients and the percentages of OCT signal enhancement for normal and cancerous breast tissues have been investigated from the experiments of 20% glucose, 40% glucose, and 20% mannitol in vitro. Obtained results indicate that the permeability coefficient in breast cancer tissue is prominently larger than that in normal breast tissue, while the optical clearing effect is just the reverse to that for each agent. The results suggest that OCT has the ability to distinguish cancer tissue from different aspect. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Dependence of optical attenuation coefficient and mechanical tension of irradiated human cartilage measured by optical coherence tomography

As banked human tissues are not widely available, the development of new non-destructive and contactless techniques to evaluate the quality of allografts before distribution for transplantation is very important. Also, tissues will be processed accordingly to standard procedures and to minimize disease transmission most tissue banks will include a decontamination or sterilization step such as ionizing radiation. In this work, we present a new method to evaluate the internal structure of frozen or glycerol processed human cartilages, submitted to various dosis of irradiation, using the total optical attenuation coefficient retrieved from optical coherence tomography (OCT) images. Our results show a close relationship between tensile properties and the total optical attenuation coefficient of cartilages. Therefore, OCT associated with the total optical attenuation coefficient open a new window to evaluate quantitatively biological changes in processed tissues.     

Three‐dimensional mapping of the attenuation coefficient in optical coherence tomography to enhance breast tissue microarchitecture contrast

Effective intraoperative tumor margin assessment is needed to reduce re‐excision rates in breast‐conserving surgery (BCS). Mapping the attenuation coefficient in optical coherence tomography (OCT) throughout a sample to create an image (attenuation imaging) is one promising approach. For the first time, three‐dimensional OCT attenuation imaging of human breast tissue microarchitecture using a wide‐field (up to ~45 × 45 × 3.5 mm) imaging system is demonstrated. Representative results from three mastectomy and one BCS specimen (from 31 specimens) are presented with co‐registered postoperative histology. Attenuation imaging is shown to provide substantially improved contrast over OCT, delineating nuanced features within tumors (including necrosis and variations in tumor cell density and growth patterns) and benign features (such as sclerosing adenosis). Additionally, quantitative micro‐elastography (QME) images presented alongside OCT and attenuation images show that these techniques provide complementary contrast, suggesting that multimodal imaging could increase tissue identification accuracy and potentially improve tumor margin assessment.