植物血凝素与金色葡萄球菌肠毒素刺激人外周血单个核细胞的比较研究

比较了植物血凝素(PHA)与金色葡萄球菌肠毒素(SEA)对外周血单个核细胞(PBMCs)的刺激效果。取健康人外周静脉血,分离得到PBMCs,分别加入PHA及SEA进行刺激并孵育12 h,利用原子力显微镜和倒置荧光显微镜观察细胞形态变化,利用量子点联合共聚焦显微镜观察活化后细胞膜表面CD3、CD69的分布情况,利用流式细胞术检测淋巴细胞活化早期细胞分化抗原CD69分子表达的变化情况。结果显示,丝裂原PHA刺激的淋巴细胞大多成群聚集,而超抗原SEA刺激的淋巴细胞大多呈分散状,且二者形态有明显差异;两组活化后淋巴细胞的体积均大于静息组,且活化过程中发生极化作用,迁移淋巴细胞,形成膜突起;丝裂原和超抗原刺激淋巴细胞12 h后,使淋巴细胞表达CD69抗原分子,但在量表达上存在差异性(PHA:39.5%±8.7%;SEA:8.3%±1.8%),抗原分子CD3和CD69在膜表面呈不均匀分布,且SEA活化后的T淋巴细胞表面受体CD3和CD69分子在空间上形成了微结构域;外周单个核细胞中其它非T细胞在丝裂原或者超抗原的刺激下也能表达活化抗原分子CD69。     

Monolithic methacrylate packed 96-tips for high throughput bioanalysis

In the pharmaceutical industry the growing number of samples to be analyzed requires high throughput and fully automated analytical techniques. Commonly used sample-preparation methods are solid-phase extraction (SPE), liquid–liquid extraction (LLE) and protein precipitation. In this paper we will discus a new sample-preparation technique based on SPE for high throughput drug extraction developed and used by our group. This new sample-preparation method is based on monolithic methacrylate polymer as packing sorbent for 96-tip robotic device. Using this device a 96-well plate could be handled in 2–4 min. The key aspect of the monolithic phase is that monolithic material can offer both good binding capacity and low back-pressure properties compared to e.g. silica phases. The present paper presents the successful application of monolithic 96-tips and LC–MS/MS by the sample preparation of busulphan, rescovitine, metoprolol, pindolol and local anaesthetics from human plasma samples and cyklophosphamid from mice blood samples.     

Chromatographic analysis of serotonin, 5-hydroxyindolacetic acid and homovanillic acid in dried blood spots and platelet poor and rich plasma samples

An isocratic high-performance liquid chromatographic method has been developed for the measurement of serotonin, 5-hydroxyindolacetic and homovanillic acids in dried blood spots and in platelet poor and rich plasma samples. Analyses were carried out on a C18 reversed-phase column using a mobile phase composed of 13% methanol and 87% aqueous citrate buffer, containing octanesulfonic and ethylendiaminotetracetic acids. Coulometric detection was used, setting the guard cell at +0.100 V, the first analytical cell at −0.200 V and the second analytical cell at +0.400 V. For the pre-treatment of biological samples a novel solid-phase extraction procedure, based on mixed-mode reversed-phase – strong anion exchange Oasis cartridges, was implemented. Extraction yields of the analytes from all these matrices were satisfactory, being always higher than 89.0%. The calibration curve was linear over the on-column concentration range of 0.1–22.5 ng mL⁻¹ for serotonin and 5-hydroxyindolacetic acid and of 0.25–22.5 ng mL⁻¹ for homovanillic acid. The sensitivity was good with a limit of detection of 0.05 ng mL⁻¹ for serotonin and 5-hydroxyindolacetic acid and 0.12 ng mL⁻¹ for homovanillic acid. Results were also satisfactory in terms of precision, selectivity and accuracy. The analytical method was successfully applied to human platelet poor and rich plasma samples and to dried blood spots from volunteers and psychiatric patients.     

基于模拟方法生成血管树的人舌三维温度场数值模拟

采用分步模拟方法生成血管树并以此作为物理模型,进行舌体三维温度场的实验研究与数值计算。计算分为舌体组织和血液温度场数值模拟两部分,相应数学模型也包括舌体组织控制方程、血液控制方程及两者之间的耦合方程。在考虑了血液与组织间的耦合换热,舌津液蒸发的影响基础上,采用数值模拟得到的舌面对流换热系数,使计算结果与红外热像验证极为近似。以模拟方法生成的血管树替代生物体的血管铸型,在某种意义上说将生物体三维传热计算方法的研究推向了一个新的层面。     

Medical application of diffraction enhanced imaging in mouse liver blood vessels

Neovascularization is correlative with many processes of diseases, especially for tumor growth, invasion, and metastasis. What is more, these tumor microvessels are totally different from normal vessels in morphology. Therefore, observation of the morphologic distribution of microvessels is one of the key points for many researchers in the field. Using diffraction enhanced imaging （DEI）, we observed the mirocvessles with diameter of about 40 μm in mouse liver. Moreover, the refraction image obtained from DEI shows higher image contrast and exhibits potential use for medical applications.     

Effects of water exchange on MRI-based determination of relative blood volume using an inversion-prepared gradient echo sequence and a blood pool contrast medium

A prostate tumor model in rats was used to compare histometric parameters of prostate cancer physiology with those obtained by magnetic resonance imaging (MRI). The study was focused on vascular physiology as reflected by relative blood volume v(b). Histometry and MRI showed a significant increase in mean v(b) in tumor compared to normal prostate tissue (histometry: normal tissue v(b)=0.69+/-0.19%, tumor tissue v(b)=1.10+/-0.31%, P<.001; MRI: normal tissue v(b)=0.67+/-0.23%, tumor tissue v(b)=1.77+/-0.67%, P<.001). The experimental work showed that MRI yielded a 60.9+/-0.76% higher v(b) than histometry in tumors, while no significant difference in v(b) was found between both methods in normal prostate tissue. Water exchange is known to affect signal intensity on contrast-enhanced MRI. This article investigated the influence of water exchange between intravascular and extravascular space to account for the discrepancy in the values of v(b) obtained with a dynamic inversion-prepared gradient echo MRI sequence and histometry in tumor and normal prostate tissue. The expected influence of water exchange on v(b) was modeled by a computer simulation of the MRI signal and compared with experimental results measured with MRI and histometry. The simulation was based on a two-compartment model indicating that v(b) may be overestimated by MRI. The magnitude of overestimation leads from 10% for the slow water exchange regime to 70% for fast water exchange. Since slow water exchange is probably predominant and even if the observed histological differences in tumor tissue are considered, an overestimation of only 15% due to water exchange is predicted by the simulation. Therefore the overestimation of tumor blood volume by MRI of 60.9% compared to histometry seems to be attributable to additional causes besides water exchange.     

大鼠的发炎白细胞的喇曼光谱研究

为了研究大鼠处于正常状态和发炎状态下白细胞内部的物质是否发生变化,制备了35%总体表面积Ⅲ度烫伤导致全身炎症的模型,采用一个激发波长为780 nm的半导体激光束来囚禁和激发正常与发炎两种状态下单个白细胞的喇曼光谱.结果显示,正常状态和发炎状态下的白细胞喇曼光谱有显著的区别,主要在726、785、935、1093、1371和1657 cm~(-1)处发炎白细胞的峰值强度比正常白细胞明显高出很多;通过光谱指认表明,当机体发炎时,白细胞中的蛋白质氨基酸含量基本没有变化,但是蛋白质结构发生明显改变;核酸的碱基含量增加,DNA双螺旋结构发生改变.利用PCA主成份对单个白细胞的喇曼光谱进行分析,发现通过PCA可以完全区分出正常状态和发炎状态的白细胞.     

Back‐propagation artificial neural network and attenuated total reflectance‐Fourier transform infrared spectroscopy for diagnosis of basal cell carcinoma by blood sample analysis

A diagnostic method for the cancer, based on investigation of infrared spectra of blood samples, has been developed. The two‐layer modified principal component feed forward back‐propagation artificial neural network (BP‐ANN) was used to classify the attenuated total reflectance‐Fourier transform infrared (ATR‐FTIR) spectra of blood samples obtained from healthy people and those with basal cell carcinoma (BCC). Results showed 98.33% of accuracy, in comparison with the current clinical methods. In the first step, 20 blood samples (10 normal and 10 cancer cases) were applied to construct the calibration model. Spectroscopic studies were performed in 900–1800 cm⁻¹ spectral region with 3.85 cm⁻¹ data space. In order to modify the capability of ANN in prediction of test samples, two different algorithms were applied. The obtained results confirmed the compatibility of the proposed network with the architecture of 20‐8‐2 (input‐hidden‐output) with the pattern model. It was concluded that analysis of blood samples by ATR‐FTIR spectroscopy and ANN chemometric technique would be a reliable approach for detection of BCC. Copyright © 2009 John Wiley & Sons, Ltd.     

Surface‐enhanced Raman scattering spectroscopy for potential noninvasive nasopharyngeal cancer detection

Combining membrane electrophoresis with surface‐enhanced Raman scattering (SERS) spectroscopy, the serum proteins were first purified and then mixed with silver nanoparticles to perform SERS spectral analysis. Therefore, the spectral signatures were enhanced to high‐fidelity SERS signatures because of the purification procedure of the first step. We used the method to analyze blood plasma samples from nasopharyngeal cancer patients (n = 43) and healthy volunteers (n = 33) for cancer detection. Principle component analysis of the SERS spectra revealed that the data points for the cancer group and the normal group form distinct, completely separated clusters with no overlap. Therefore, the nasopharyngeal cancer group can be unambiguously discriminated from the normal group, i.e., with both diagnostic sensitivity and specificity of 100%. These results are very promising for developing a label‐free, noninvasive, and reliable clinical tool for rapid cancer detection and screening. Copyright © 2011 John Wiley & Sons, Ltd.     

Mutual information analysis reveals bigeminy patterns in Andersen-Tawil syndrome and in subjects with a history of sudden cardiac death

Herein we introduce the Mutual Information Function (MIF) as a mathematical method to analyze ventricular bigeminy in certain pathological conditions of the heart known to be associated with frequent ventricular arrhythmias. In particular, we show that the MIF is sensitive enough to detect the bigeminy pattern in symbolic series from patients with Andersen-Tawil syndrome as well as in a group of patients from the Sudden Cardiac Death Holter Databases. The results confirm that MIF is an adequate method to detect the autocorrelation between the appearance of sinus and ventricular premature beats resulting in a bigeminy pattern. It is also shown that MIF reflects the bigeminy patterns as a function of the percentage of ventricular premature beats present in the symbolic series and also as a function of the percentage of bigeminy. The MIF was also useful to establish a consistent difference in the bigeminy pattern related to the diurnal and nocturnal periods presumably associated to the circadian rhythm of the heart. Understanding of the ventricular bigeminy patterns throughout 24-hours could provide some insights into the pathogenesis of ventricular tachyarrhythmias in these pathological conditions.