Microwave reflection and transmission measurements for pulmonary diagnosis and monitoring

The potential of using low intensity penetrating microwave energy in diagnosis and monitoring of pulmonary diseases such as edema and emphysema has been investigated theoretically and in selected animal models. These diseases are characterized by changes in total lung water which modify the permittivity and conductivity of the lung tissue, and consequently affect the microwave reflection from or transmission through the lung. Both reflection and transmission measurement techniques have been examined. Animal experiments have indicated changes in microwave reflection with lung water changes. The diagnostic capabilities of transmission measurements have been evaluated experimentally on a phantom model, and theoretically on a planelayered tissue model.     

人肺癌组织细胞NHE-1mRNA表达及其意义的研究

目的：研究人肺癌组织细胞ＮＨＥ－１基因表达水平;探讨人肺癌细胞在整体条件下ＰＨｉ调节的分子机制及其生物学意义。方法：以半定量逆转录ＰＣＲ研究了１４例人肺癌组织手术新鲜标本的ＮＨＥ－１ｍＲＮＡ的表达水平。结果：人肺癌组织细胞ＮＨＥ－１ｍＲＮＡ表达水平非常显著地高于正常肺组织（Ｐ〈０．００１）,系正常肺组织的１１．８１倍。结论：人肺癌组织细胞通过上调ＮＨＥ－１基因超表达,以增强Ｎａ＾＋／Ｈ＾＋交换,可     

人肺组织内源性显微荧光特性研究

采用新型显微荧光分光光度系统 ,实现激光诱导人肺组织内源性显微荧光光谱与图像的测量 ,获得不同组织层 (即上皮层 ,粘膜层和软骨层 )的荧光分布和荧光特性 ,为探索癌与正常组织自体荧光光谱特征差异的根源 ,揭示激光诱导自体荧光法诊断和定位早期肺癌的机理提供重要的实验依据     

基于小波变换的多神经网络胸片骨骼分离

胸片中,因大量肺结点被锁骨或肋骨遮挡而被放射科医生忽略。为了从胸片图像中分割出骨骼结构,提出了一种基于小波变换的多分辨率人工神经网络,以获取去除骨骼结构的虚拟软组织胸片。该方法可有效保证肺结点与血管的清晰度,且分离出骨骼和软组织可有效地帮助放射医生检测肺结点。     

盐酸戊乙奎醚预处理对大鼠失血性休克致急性肺损伤时p38MAPK信号通路的影响

目的：观察盐酸戊乙奎醚预处理对大鼠失血性休克致急性肺损伤（ALl）时p38MAPK信号通路的影响,探讨盐酸戊乙奎醚对失血性休克致ALI的肺保护机制。方法：健康SD大鼠40只,体重200g至250g,随机分为5组（n=8）：假手术组（A组）、失血性休克组（B组）、盐酸戊乙奎醚低剂量组（C组）、中剂量组（D组）和高剂量组（E组）。A组仅行动静脉穿刺不放血,B组股动脉放血至40±5mmHg制作失血性休克模型,C、D、E组分别于放血前30min股静脉注射盐酸戊乙奎醚0.3mg/kg、1.0mg/kg、3.0mg/kg,随后制作失血性休克模型。各组复苏后4h处死大鼠取肺组织,RT-PCR检测肺组织TLR-4mRNA的表达水平,免疫组化法检测肺组织p38MAPK的蛋白表达：并测定肺湿/干重比（W/D）和观察肺组织病理学变化。结果：与A组比较,B组和C组TLR-4mRNA、p38MAPK蛋白表达水平及W/D比值升高（P〈0.05或P〈0.01）,与D组和E组差异无统计学意义（P〉0.05）;与B组比较,D组和E组TLR-4mRNA、p38MAPK蛋白表达水平及W/D比值降低（P〈0.05或P〈0.01）,C组上述指标差异无统计学意义（P〉0.05）;D组与E组上述指标差异无统计学意义（P〉0.05）。光镜观察：C组、D组、E组肺泡间隔增宽及多形核白细胞浸润程度均较B组减轻。结论：盐酸戊乙奎醚预处理可通过抑制p38MAPK信号转导通路的激活,减轻失血性休克所致的大鼠急性肺损伤,且有剂量依赖性。     

Lactoferrin in human lung tumors

Immunodiffusion technique was used to study the lactoferrin (LF) distribution in human fetal, normal and tumour tissue extracts. If was found that LF concentration in lung tumour extracts was higher than in normal lung one. Indirect immunoperoxidase method revealed LF in alveolar macrophages of normal and tumour lung tissues, in afflux of these cells around the tumour cells, but never--in the original lung cancer cells. It is suggested that LF is not a lung tumour-associated antigen.     

Relations Between Fractional-Order Model Parameters and Lung Pathology in Chronic Obstructive Pulmonary Disease

In this study, changes in respiratory mechanics from healthy and chronic obstructive pulmonary disease (COPD) diagnosed patients are observed from identified fractional-order (FO) model parameters. The noninvasive forced oscillation technique is employed for lung function testing. Parameters on tissue damping and elastance are analyzed with respect to lung pathology and additional indexes developed from the identified model. The observations show that the proposed model may be used to detect changes in respiratory mechanics and offers a clear-cut separation between the healthy and COPD subject groups. Our conclusion is that an FO model is able to capture changes in viscoelasticity of the soft tissue in lungs with disease. Apart from this, nonlinear effects present in the measured signals were observed and analyzed via signal processing techniques and led to supporting evidence in relation to the expected phenomena from lung pathology in healthy and COPD patients.      

丹顶鹤肺脏组织学及超微结构研究

本文应用光镜、扫描及透射电镜对一例成熟丹顶鹤肺脏进行了系统的观察。结果表明:丹顶鹤肺脏系有各级支气管和无数肺小叶及小叶间结缔组织构成。肺小叶呈六面棱柱形,包括副支气管,肺房,漏斗和呼吸毛细管。呼吸毛细管上皮,毛细血管内皮及其下基膜共同组成气-血屏障。     

Antimetastatic effect of the delta-sleep peptide during stress in mice with Lewis' lung carcinoma

The experiments on C57Bl mice with metastatic Lewis lung carcinoma have shown that peptide delta-sleep (DSIP) lowers the stimulation of metastatic spreading which is observed in combination of the surgical removal of the tumour with the emotional-painful stress. The antimetastatic effect is accompanied by stabilization of neurohumoral indices, by a decrease in the intensity of lipid peroxidation and of the acid cathepsin activity in the blood vessels and in the lung tissue.     

Pulmonary Targeting Crosslinked Cyclodextrin Metal–Organic Frameworks for Lung Cancer Therapy

Lung cancer is a serious threat to human health with the highest morbidity and mortality; metastatic lung cancer accounts for a majority of cancer-related deaths. Hence, there is considerable interest in developing efficient lung-targeted drug delivery systems to improve overall survival and quality of life of lung cancer patients. Based on the lung-targeting characteristics of cubic crosslinked cyclodextrin metal–organic framework (CDF) nanoparticles, this study shows the synthesis of a nanoplatform using RGD-functionalized CDF to co-deliver low-molecular-weight heparin (LMWH) and doxorubicin (DOX) for treatment of lung cancer. Rational design of the DOX-loaded RGD-CDF-LMWH nanoplatform (RCLD) is carried out. RCLD nanoparticles are efficiently targeted to lung tumors following intravenous administration; RCLD accumulation in the lung is 5.8 times greater than that in the liver. Moreover, RCLD inhibits migration and invasion of cancer cells in vitro and significantly diminishes lung tumor nodule count and area of spread in human A549 and murine B16F10 lung cancer models in vivo. Furthermore, RCLD does not show serum enzyme or histopathologic indicators of tissue damage or adverse hematologic effects. Therefore, the multiple antitumor activities of this novel RCLD nanoplatform, alongside its safety profile for normal tissues, strongly support its use for targeted treatment of lung cancer.     

Modeling real-time 3-d lung deformations for medical visualization.

In this paper, we propose a physics-based and physiology-based approach for modeling real-time deformations of 3-D high-resolution polygonal lung models obtained from high-resolution computed tomography (HRCT) images of normal human subjects. The physics-based deformation operator is nonsymmetric, which accounts for the heterogeneous elastic properties of the lung tissue and spatial-dynamic flow properties of the air. An iterative approach is used to estimate the deformation with the deformation operator initialized based on the regional alveolar expandability, a key physiology-based parameter. The force applied on each surface node is based on the airflow pattern inside the lungs, which is known to be based on the orientation of the human subject. The validation of lung dynamics is done by resimulating the lung deformation and comparing it with HRCT data and computing force applied on each node derived from a 4-D HRCT dataset of a normal human subject using the proposed deformation operator and verifying its gradient with the orientation.     

Scanning electron microscopic changes in the morphology of rabbit pulmonary tissue biopsied following ischemia and reperfusion: a window of opportunity?

Reperfusion is known to cause tissue damage in ischemic pulmonary tissue. We investigated the time frame of this occurrence by examining electron microscopic changes in lung tissue. Isolated, perfused, and ventilated rabbit lungs (and heart) were placed en bloc in a 37 degrees C chamber and perfused through the pulmonary artery at 15 mm Hg pressure with oxygenated Krebs-Henseleit buffer, pH 7.4, 70 ml min(-1), for 20 min and the pulmonary pump and ventilator were stopped. The resultant ischemic state was maintained for 2 h, and reperfusion resumed with the same buffer. The lungs of four groups of rabbits (n = 5 per group) were each subjected to 30 min, 1, 2, and 4 h of reperfusion respectively. Upon completion, lungs were biopsied for scanning electron microscopy. Ischemic damage including the loss of lung architecture, and edema were seen. Reperfusion restored some of the tissue anatomy and the return to normalcy increased up to 1 h of reperfusion after which the damage increased with time. Results suggest that damage due to ischemia alone may be reversible. Initial recovery is due to the re-establishment of circulation. However, with time, the damage seen may be due to free radicals and with 4 h of reperfusion, cell death may have occurred.     

肺癌切片的拉曼光谱分析

应用激光显微拉曼光谱法对肺癌变及癌旁正常组织冰冻切片进行了分析研究.结果表明:正常肺组织切片的1392cm-1附近的C-H变形振动在癌变组织光谱中向高波数移动约6cm-1;1523cm-1脂类类胡萝卜素的C=C振动谱带在癌变组织光谱中向高波数移动约3cm-1;在正常组织中1610cm-1处谱带的强度明显强于1526cm-1处谱带的强度,而在癌变组织中则正好相反.说明肺部正常和癌变组织的激光显微拉曼光谱有显著差异,这些差异有可能成为组织癌变的判据.     

A Computer Method for Counting the Number of Alveoli per Unit Area of Human Lung Tissue

This paper describes a simple automated procedure for counting the number n of alveoli per unit area of human lung tissue.     

Measurement of lung hyperelastic properties using inverse finite element approach

Hyperelastic properties of deflated lung tissue have been characterized via an inverse finite element approach. Such properties are useful in many medical diagnosis and treatment applications where tissue deformation can be modeled to account for during the procedure. Several indentation experiments were conducted on various porcine lungs' tissue specimens resected immediately from different regions and lobes after the animals were sacrificed. Three different strain energy models, namely Ogden, Yeoh, and Polynomial, were used and respective hyperelastic parameters were obtained. The parameters for each model were estimated through an optimization process where the experimental force-displacement profiles of indentation were fitted to those obtained from finite element simulations performed specifically for the samples' geometries. Results obtained in this investigation for all the three models indicate convergence with reasonably low average fitting errors ranging from 2.3% to 6.2%. Independent tests were also performed to assess the effects of samples' heterogeneities on the obtained parameters. The outcome of these tests was encouraging and confirmed small impact of tissue inhomogeneities on the estimated parameters. The reported hyperelastic properties can, accordingly, pave the way for more accurate biomechanical modeling of the lung's soft tissue in the emerging applications of minimally invasive medical intervention for lung cancer diagnosis and treatment.     

RF Energy Deposition in a Heterogeneous Model of Man: Near-Field Exposures

The electric field strength was measured in a full-scale heterogeneous model of man exposed in the near field of resonant dipoles. The model was comprised of skull, spinal cord, rib cage, all other major bones, brain, lung, and muscle tissue. Electrical properties of these simulated tissues were the same as respective live tissue properties at test frequencies of 160, 350, and 915 MHz. The rates of energy absorption were calculated on the basis of the measured field strengths and tissue conductivities. Patterns of the energy deposition are compared for two orientations of the antennas with respect to the body. Also the results for the heterogeneous model are compared to data for homogeneous model having average tissue electrical properties.     

Evolution of Bioengineered Lung Models: Recent Advances and Challenges in Tissue Mimicry for Studying the Role of Mechanical Forces in Cell Biology

Mechanical stretch under both physiological (breathing) and pathophysiological (ventilator‐induced) conditions is known to significantly impact all cellular compartments in the lung, thereby playing a pivotal role in lung growth, regeneration and disease development. In order to evaluate the impact of mechanical forces on the cellular level, in vitro models using lung cells on stretchable membranes have been developed. Only recently have some of these cell‐stretching devices become suitable for air–liquid interface cell cultures, which is required to adequately model physiological conditions for the alveolar epithelium. To reach this goal, a multi‐functional membrane for cell growth balancing biophysical and mechanical properties is critical to mimic (patho)physiological conditions. In this review, i) the relevance of cyclic mechanical forces in lung biology is elucidated, ii) the physiological range for the key parameters of tissue stretch in the lung is described, and iii) the currently available in vitro cell‐stretching devices are discussed. After assessing various polymers, it is concluded that natural‐synthetic copolymers are promising candidates for suitable stretchable membranes used in cell‐stretching models. This work provides guidance on future developments in biomimetic in vitro models of the lung with the potential to function as a template for other organ models (e.g., skin, vessels).     

肝脏和肺组织的太赫兹光谱成像

与红外辐射、X射线、核磁共振、超声波等传统医疗诊断技术相比,太赫兹技术具有能量低、空间分辨力高和带宽宽等独特分析能力,成为人体成像或人体组织癌症诊断技术的补充技术。分别对肝脏和肺的正常组织与肿瘤组织做了太赫兹光谱检测与太赫兹成像研究,通过肝脏的光谱检测与成像实验总结出相关经验,使得肺癌组织太赫兹成像得到了明显的效果,并且发现肺癌肿瘤组织在1.0 THz~1.75 THz频率范围内的太赫兹成像能够明显区分出正常组织与肿瘤组织,且频率越高,成像分辨力越高。     

Scanning electron microscopic study on dendritic cells and fibroblasts in connective tissue.

Perfusion fixation and intravascular resin injection were used to study in situ the cells of superficial fascia (loose connective tissue) of the rat limb by scanning and transmission electron microscopy. These procedures enabled us to differentiate fibroblasts, representative cells of the connective tissue and so-called "dendritic cells," the other cellular constituent of the tissue, known as possible antigen presenting cells. "Dendritic cells" were amoeboid with some spatular processes by which the cells clung to the collagen fiber bundles. The fine structures characteristics of macrophages; they contained abundant primary and secondary lysosomes and expressed factor XIIIa in their cytoplasm. Fibroblasts, on the other hand, were attenuated, sheet-like cells whose edges were juxtaposed closely to collagen and elastic fibers, and were further anchored by microfibrils. The cells were usually interconnected to each other with gap junctions, thus producing a cellular network in the connective tissue.     

Phased-Array Design Considerations for Deep Hyperthermia through Layered Tissue

Results are presented which demonstrate localized heating at depth, by a phased array in a homogeneous thorax phantom and the problems caused by a more realistic case of a layered tissue equivalent phantom. A phased array of contacting radiators is proposed for overcoming the difficulty of selective heating within the body cavity caused primarily by the muscle layer. The field from one aperture radiator in contact with layered tissue is predicted by a planar spectral diffraction algorithm incorporating transmission and reflection operations on the plane wave spectrum. This prediction process is validated by experimental results. The algorithm enables the prediction of a minimum number of phased contacting radiators required for selective heating within lung tissue through fat and muscle layers at 2.45 GHz, and provides a guide for the design requirements of a multiapplicator system.