In vitro evaluation study of the membrane autotransfusion system experimental prototype: MATS-I

Abstract: Membrane Autotransfusion System (MATS) utilizing plasmapheresis technology has been developed in our laboratory. A specially designed polyethylene hollow fiber membrane was utilized. This study was conducted to evaluate performance of the first experimental prototype, MATS-I. The results of this study showed that the MATS-I could concentrate diluted blood at 10% of the initial hematocrit concentration (HCTi) into over 40% after passing through the system at a transmembrane pressure of 70 mm Hg. Moreover, the MATS-I can continuously treat 10,000 ml of diluted blood at various HCTi levels without deteriorating its performances. Even though the MATS-I met all required performances as an autotransfusion system, several areas of improvement of the system were necessary to meet various clinical needs. The next prototype, MATS-II, can be designed based on experiences obtained from the MATS-I. The MATS is smaller, more atraumatic and continuous, and is a faster system when compared to the currently available centrifugal autotransfusion devices.     

基于小波变换极大模的多模医学图像融合

多模态医学图像融合由于其对医学临床诊断的意义已引起广泛的关注,基于图像边缘特性的融合方法逐渐成为研究的重点。本文提出了一种基于离散二进小波变换的多尺度边缘检测和图像融合的方法,实现了特征级图像融合。不同于以往的从极大模值点直接重建图像,本文的算法利用极大模值点建立有效的融合规则,然后从融合的小波系数重构信号。融合图像的交互信息和峰值信噪比等检测指标表明此方法优于传统融合算法。     

RELATIONSHIP OF THE EXPRESSION OF MDR1 GENE PRODUCT IN HEPATO CELLULAR CARCINOMA TO INVASION AND METASTASIS

ＩＮＴＲＯＤＵＣＴＩＯＮＰｇｌｙｃｏｐｒｏｔｅｉｎ（Ｐｇｐ），ｔｈｅｐｒｏｄｕｃｔｏｆｔｈｅｍｕｌｔｉｄｒｕｇｒｅｓｉｓｔａｎｃｅ（ＭＤＲ１）ｇｅｎｅ，ｉｓａ１７０Ｋｄａｍｅｍｂｒａｎｅｐｒｏｔｅｉｎｒｅｓｐｏｎｓｉｂｌｅｆｏｒｐｕｍｐｉｎｇ...     

复方益智汤对小鼠学习和记忆能力的影响

采用跳台实验和水迷宫实验方法，观察复方益智汤对由樟柳碱、环已酰亚胺和３０％乙醇造成的小鼠记忆障碍病理模型的影响。结果表明，复方益智汤可不同程度地改善小鼠学习和记忆的获得、巩固和再现能力。     

Virtual computed tomography colonoscopy: artifacts, image quality and radiation dose load in a cadaver study

The purpose of our study was to evaluate the interdependency of spatial resolution, image reconstruction artifacts, and radiation doses in virtual CT colonoscopy by comparing various CT scanning protocols. A pig's colon with several artificial polypoid lesions was imaged after air insufflation with helical CT scanning using 1-, 3-, and 5-mm collimation, and pitch values varying from 1.0 to 3.0. Virtual endoscopic images and “fly through” sequences were calculated on a Sun Sparc 20 workstation (Navigator Software, GE Medical Systems, Milwaukee, Wis.). Several reconstruction artifacts as well as overall image quality were evaluated by three independent reviewers. In addition, radiation doses for the different CT protocols were measured as multiple-scan average dose using a 10-cm ion chamber and a standard Plexiglass body phantom. Generally, image quality and reconstruction artifacts were less affected by pitch values than by beam collimation. Thus, narrow beam collimation at higher pitch values (e. g. 3 mm/2.0) seems to be a reasonable compromise between quality of virtual endoscopic images and radiation dose load. Received: 4 February 1999; Revised: 16 June 1999; Accepted: 17 June 1999     

High-resolution magnetic resonance and volume rendering of the labyrinth

Our aim was to verify the feasibility of volume rendering (VR) of high-resolution magnetic resonance (HR-MR) data sets of the labyrinth. We retrospectively reviewed the HR-MR data sets of 16 consecutive patients with no MR evidence of labyrinthine pathology. High-resolution MR data sets were obtained by means of a 3D T2-weighted FSE sequence with the use of a 3-in. circular surface coil for signal reception, and processed with a high-end workstation. Two reviewers performed separately VR of the labyrinth by selecting the signal intensity interval for attribution of opacity and transparency. Concerning the time taken for definition of the volume of interest, the two observers needed, respectively, 28.9 and 33.1 min (SD ± 8.7–9.5 min), whereas the time taken for VR was respectively, 26 and 33.2 min (SD ± 8.8–8.9 min). Concerning the selection of the signal intensity interval, the two observers had, respectively, 86.4 and 88.7 mean lower threshold (SD ± 34.5–33.5), 488.9 and 495.4 mean upper threshold (SD ± 56.3–53.8). In our experience, we have found VR of HR-MR to offer a reliable and reproducible technique for producing 3D representations of the labyrinth. The VR algorithms use all data within the imaging volume and optimize the dynamic range ascribed to the object being visualized. Received: 9 October 1998; Revised: 14 January 1999; Accepted: 30 June 1999     

Depression of long term potentiation in gerbil hippocampus following postischemic hypothermia

To investigate the mechanism of chronic cell death following postischemic hypothermia, the change of N-methyl- -aspartate receptor (NMDAR) were examined by immunohistochemistry of NMDAR1 and long-term potentiation (LTP) in the CA1 subfield of the gerbil hippocampus. At 1 week following postischemic hypothermia (32°C×4 h), all CA1 neurons survived; however, immunoreactivity of NMDAR1 increased in neuronal perikarya whereas decreased in dendrites in the CA1 neurons. The abnormality was still observed in remaining CA1 neurons at 1 month after hypothermia. LTP was also significantly depressed at 1 week after hypothermia. These results suggest that some abnormalities in the glutamate receptor may be caused by ischemia; such abnormality would persist in spite of hypothermia treatment, resulting in the depression of LTP.     

Modulation of dihydroxyphenylacetaldehyde extracellular levels in vivo in the rat striatum after different kinds of pharmacological treatment

We recently identified the direct product of dopamine (DA) by monoamine-oxidase (MAO) activity, dihydroxyphenylacetaldehyde (DOPALD) in the trans-striatal dialysate. Based on these findings, in this work, we directly measured the variations in DOPALD levels after various kinds of pharmacological treatment in rat striatal extracellular fluid. Using both reversible and irreversible MAO inhibitors, we found that MAO-A inhibition suppressed, whereas MAO-B inhibition did not modify DOPALD levels in the dialysate. The vesicular DA uptake blocker Ro 4-1284 led to an increase in extracellular DA and DOPALD, whereas the increase in extracellular DA obtained after administration of the plasma membrane DA uptake blocker GBR-12909 occurred without concomitant changes in DOPALD extracellular levels. Microinfusions of DA through the dialysis probe or systemic administration of L-DOPA increased striatal DOPALD to a greater extent compared with other DA metabolites, both in intact and in 6-hydroxydopamine (6-OHDA)-lesioned striatum. This study indicates that the direct product of MAO activity within the rat striatum derives from the activity of the isoenzyme MAO-A. The assay of DOPALD, together with DOPAC, represents a reliable tool to measure directly, in freely moving animals, DA oxidative metabolism. As recent studies have shown that microinfusions of exogenous DOPALD might induce cell death, pharmacological modulation of DOPALD levels might also be relevant for an understanding of the mechanisms involved in DA neurotoxicity.     

基于变精度粗糙-模糊集模型的诊断知识获取

提出一种基于变精度粗糙-模糊集模型的诊断知识获取算法,利用相似性聚类方法自动获取模糊隶属函数,将连续属性表示成模糊值,通过定义模糊相似关系和模糊相似类给出了变精度粗糙-模糊模型的近似表示,并引入蚁群算法求取模糊相似关系下的属性约简,进行诊断知识的获取。将其应用于精对苯二甲酸生产过程尾氧浓度故障诊断知识获取中,结果表明:该算法可以从故障数据中提取更客观有效的诊断规则,在实际故障诊断中具有很好的应用价值。     

单细胞凝胶电泳图像分析系统1.0的设计

目的设计单细胞凝胶图像分析系统(IM I),并确定系统的可靠性与准确性。方法分析模拟彗星图像、用户使用情况、DNA损伤模型毒物H2O2的DNA损伤作用、被引用文献情况以及与权威的KS400彗星图像分析系统进行比较。结果IM I分析得出的尾矩准确度98.7%,H2O2引起的DNA损伤存在剂量—反应关系。IM I与KS400分析结果具有高度相关性,尾长相关系数r=0.997 6,P<0.000 1,尾矩相关系数r=0.996 4,P<0.000 1。近4年来,使用IM I作为研究工具发表的文献17篇,其中论著12篇。结论通过作者以及其他科研工作者的几年来的研究,表明IM I是一种可靠的彗星图像分析工具。