Transductive Machine Learning for Reliable Medical Diagnostics

In the past decades Machine Learning tools have been successfully used in several medical diagnostic problems. While they often significantly outperform expert physicians (in terms of diagnostic accuracy, sensitivity, and specificity), they are mostly not being used in practice. One reason for this is that it is difficult to obtain an unbiased estimation of diagnoses reliability. We discuss how reliability of diagnoses is assessed in medical decision making and propose a general framework for reliability estimation in Machine Learning, based on transductive inference. We compare our approach with a usual (Machine Learning) probabilistic approach as well as with classical stepwise diagnostic process where reliability of diagnose is presented as its posttest probability. The proposed transductive approach is evaluated on several medical data sets from the UCI (University of California, Irvine) repository as well as on a practical problem of clinical diagnosis of the coronary artery disease. In all cases significant improvements over existing techniques are achieved.     

Protecting Medical Data for Decision-Making Analyses

In this paper, we present a procedure for data protection, which can be applied before any model building based analyses are performed. In medical environments, abundant data exist, but because of the lack of knowledge, they are rarely analyzed, although they hide valuable and often life-saving knowledge. To be able to analyze the data, the analyst needs to have a full access to the relevant sources, but this may be in the direct contradiction with the demand that data remain secure, and more importantly in medical area, private. This is especially the case if the data analyst is outsourced and not directly affiliated with the data owner. We address this issue and propose a solution where the model-building process is still possible while data are better protected. We consider the case where the distributions of original data values are preserved while the values themselves change, so that the resulting model is equivalent to the one built with original data.     

Agent Oriented Approach to Handling Medical Data

Medical treatment of a patient could be represented as a circle of the following actions: examination, diagnostics, and therapy. The aims of the actions are to find out the patients state of health and consequently to conclude about possible diseases and finally to choose a suitable therapy. In long term, the circle of actions repeat as long as the patient is not healthy. Efficiency of this treatment depends on the knowledge and the experiences of the physicians involved. Information technology offers many possibilities to help the physicians increase the efficiency and the quality of this work. In the article, we present an agent-oriented computer-based health care service, which uses information from different data sources that are physically distributed across several sites. Such a decentralized approach mirrors the organizational structure of a health service and it is very similar to an agent-oriented view of the world.     

Diagnostic Process From the Data Quality Point of View

The spread of electronic use of data in various areas has put importance of data quality to higher level. Data quality has syntactic and semantic component; the syntactic component is relatively easy to achieve if supported by tools (either off-the-shelf or our own), while semantic component requires more research. In many cases such data come from different sources, are distributed across enterprise and are at different quality levels. Special attention needs to be paid to data upon which critical decisions are met, such as medical data for example. The starting point for research is in our case the risk of the medical area. In the paper we will focus on the semantic component of medical data quality.     

Experimental study of yishou tiaozhi tablet on free radical metabolism in aging model mice

Objective: To observe the effect of Yishou Tiaozhi tablet (YSTZT) on the metabolism of free radical in mice of aging model.Methods: Using the aging model induced by hypodermic injection of 5% Dglalactose in mice for forty days. The content of malondialdehyde(MDA) and activity of Superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) in serum, activity of monoamine oxidase B (MAO-B), Na+-K+-ATPase in brain were investigated after treatment.Results: Compared with the aging model group, it showed that YSTZT could obviously inhibit the increase of level of MDA in serum and the activities of MAO-B in brain; and enhance the activities of SOD, GSH-Px in serum, and the activities of Na+ -K+ -ATPase in brain. Furthermore, YSTZT could obviously elevate the tolerance to fatigue and hypoxia in mice.Conclusion: YSTZT could effectively improve the free radical metabolism of senile body, it is an ideal and effective medicine in preventing aging, which is also one of the experimental basis in proving the theory of ”Spleen and Kidney Deficiency complicated with Stasis and Phlegm causes aging”. This study was funded by Overseas Chinese Affairs Office of the State Council (No. 93-95-47)     

Study on mechanism of huanshao dan in brain protectionΔin brain protectionΔ

Objective: To observe the behavioral and biochemical effects of a traditional Chinese medicine Huanshao Dan (HSD) on learning and memory deficits in transient cerebral ischemia model in mice.Methods: Step-through experiments, receptor binding test and choline acetyltransferase (ChAT) activities determination were performed.Results: Mice undertaken transient ischemia commited much more mistakes in step-through experiments and showed relatively higher³ H-MK801 binding in cerebral cortex and hippocampus than in sham operated animals. HSD decoction was most effective in reducing these mistakes in mice. At the same time, and³ H-MK801 binding of cerebral cortex and hippocampus tissues were also significantly decreased, while ChAT activities in the same tissues were increased.Conclusion: HSD might antagonize ischemic injury of brain through inhibition of glutamate N-methyl-D-Aspartic acid receptor overactivity. ΔThis program was supported by National Nature Science Foundation of China (No.39421012)     

Clinical studies on bladder tumor-associated antigen in serum of patients with bladder cancer by using monoclonal antibody and sandwich ELISA

Investigations on tumor-associated antigen in the serum of patients with bladder cancer by using monoclonal antibody Hb 7A and sandwich ELISA were carried out on 36 patients with bladder cancer (BCa group), 18 patients with other tissue tumor (OTT group) and 22 normal subjects (control group). The average OD value of Hb 7A antigen of BCa group, OTT group and control group was 0.315±0.033, 0.124±0.026 and 0.12±0.021 respectively. The OD value of Hb 7A antigen in BCa group was significantly higher than that of control group and of OTT group (P< 0.01), but there was no obvious difference between the control group and OTT group (P> 0.05). The positive detection rate in BCa group was 86% (31/36,), while detection in all 22 normal subjects and the 18 patients of OTT group yielded negative results. The results indicated that the method of using McAb Hb 7A and sandwich ELISA, characterized by high specificity and sensitivity, is of value for clinical diagnosis and follow-up of patients with bladder cancer and general survey of persons at high risk of bladder cancer.     

Optimization of Nanoparticle Drug Microcarrier on the Pharmacokinetics of Drug Release: A Preliminary Study

Ideal drug delivery process would exhibits zero-order kinetics. However, in practical, most drug delivery process is first-order kinetics. This study is aimed to mathematically model, analyze and determine the optimal polymer shape of the drug micro-carrier that achieves a near zero-order release. We also extend study in deriving and optimizing theoretically the optimal distance between the two optimal micro-carrier shapes. A mathematical model that derived from Carslaw and Jaeger equation of conduction of heat is used to model the relationship between the geometry shape of the carrier and the drug concentration. An optimization objective function is formulated from the mathematical model and MATLAB Optimization Toolbox is used to perform the numerical analysis. The results suggest that reducing the k value (ratio of volume of the fluid to that of the sphere) gives a near zero-order kinetics drug delivery response for all the microcarrier geometry shapes (with equivalent surface area/volume ratio to a sphere with radius R _s ) investigated. Our preliminary results showed that tetrahedron microcarrier exhibits the best response and the worst response is for tablet (with R = R _s /2).     

Über EKG-Kennzeichungen der atrioventrikulären akzessorischen Leitungsbahnen von Rechtsmittel septa und Linksmittelsepta

Zusammenfassung  In der Studie wurden 20 Patienten mit AV-Reentry-Tachykardie unter Einbezug einer mittelseptalen gelegenen atrioventricul?ren akzessorischen Leitungsbahn (MS) eingeschlossen, die seit 4 Jahren in unserem Elektrophysiologischen Untersuchungslabor mittels Katheters erfolgreich abladiert wurden. Die 20 Patienten hatten 26 akzessorische Leitungsbahnen. Daunter waren 21 MS (rechtsmittelseptal (RMS) zu linksmittelseptal (LMS) = 17: 4). 18 akzessorische Leitungsbahnen waren offen. Die Lokalisation der akzessorischen Leitungsbahnen wurde aufgrund der Stelle erfolgreich abladiert bestimmt. Die Ergebnisse zeigten, da? die RMS und LMS den gleichen Charakter in den meisten Ableitungen des EKGs hatten, und jedoch der wenige Unterschied bei diesen beiden akzessorischen Lritungsbahnen besteht. Wenn die positive Polarit?t der Delta-Welle in der Ableitung Vi bei der Patienten mit MS auftritt, mu? sich überlegen, ob die M?glichkeit der Lokalisation der akzessorischen Leitungsbahn im Linksmittelseptum besteht.

     

Biomechanische Untersuchungsergebnisse über die verbesserte Verankerung von Pedikel schrauben mit resorbierbarem Zement in menschenlichen Wirbel körpern

Zusammenfassung  Die Prim?rstabilit?t von Pedikelschrauben im Knochen h?ngt in hohem Masse von der Knochendichte ab. Die Augmentation mit Zement ist ein klinisch einsetzbares Verfahren, um die Schrauben-Verankerung im osteoporotischen Knochen zu verbessern. In dieser Studie wurde eine neuartiges resorbierbares Knochenersatzmaterial (α-BSM™) für diese Augmentation benutzt. Biomechanische Testungen wurden in vitro bei 16 Lendwirbelk?rpern (L3-L5) aus 6 Individuen (75,2 ±13,7 Jahre) durchgeführt. Vor der biomechanischen Testung wurde bei allen Pr?paraten die trabekul?re Knochendichte mittels pQCT gemessen und beide Pedikel mit USS-Pedikelschrauben (5, 0 mm X 45 mm) besetzt, von welchen eine mit α-BSM™ augmentiert war. Beim axialen Auszugstest wurden die maximale axiale Auszugskraft (F-max) sowie die Energieaufnahme bestimmt. Der Medianwert der F-max stieg beim Auszugstest durch die Zementierung mit α-BSM™ um 80 % von 370 N (ohne Zement) auf 665 N (mit Zement). Die Energieaufnahme bis zum Erreichen der F-max (E-F-max) und bei Dislokation bis 2,0 mm (E-2 mm) steigerte sich ebenfalls um 83 % und 68 %. Die Unterschiede waren signifikant. (Wilcoxon’s-Test,P<0,01) Die Ausreisskr?fte F-max (ohne oder mit Zement) korrelierten eng mit der Knochendichte (r=0,9056 und r=0,9585). Unsere Resultate zeigen, da? eine Augmentation mit dem α-BSM™ die prim?re Stabilit?t von Pedikelschrauben verbessern kann. Der Effekt scheint auf einer Optimierung der Kontaktfl?che und einer Aussteifung der schraubennahen Spongiosa zu beruhen. Das Material k?nnte geeignet sein, die Verankerung von Pedikelschrauben bei osteoporotischen Patieten zu verbessern.

     

Über die erbliche sensorische radikuläre Neuropathie

Der Autor berichtet über seine Untersuchungsresultate bei erblicher sensorischer radikul?rer Neuropathie. Er hat 4 Generationen einer Fabmilie untersucht und 4 F?lle gefunden, davon 2 in der dritten und 2 in der vierten Generation. Alle 4 F?lle sind m?nnlich, es handelt sich also sehr wahrscheinlich um X-gebundenen rezessiven Erbgang in dieser Familie. Bci 2 F?llen bestanden postulzer?se narbige Defekte an der Zungenspitze und bei einem Fall postherpetische Trübung auf der Hornhaut des linken Auges. Diese beiden Syndrome werden sehr selten beobachtet; in der bisherigen Literatur wurde kein Bericht darüber gefunden. In bezug auf den pathogenetischen Mechanismus dieser Erkrankung k?nnten sie die Hypothese unterstützen, da? die “Abiotrophie” des Ganglion radiculare posterior die Ursache der Krankheit ist, und da? hier der Krankheitsherd, n?mlich das Ganglion semilunare des N. trigeminus ontogenetisch dem Ganglion radiculare posterior des N. spinalis analog ist.     

加强医德医风档案管理促进医院医德医风建设

医德医风建设是医院日常管理工作的重要方面,也是社会普遍关注的热点问题。医德医风建设的主体是医务工作者,而医德医风档案是医务工作者进行医德实践活动的结晶,它能够为医学伦理学研究和医院加强医德医风管理,进行职业道德建设提供参考依据。建立医德医风档案对加强廉洁行医、树立良好的医德医风具有不可估量的作用,作为医务人员日常行为的纪实,能否充分利用并发挥作用,是值得我们认真思考和探索的课题。     

国产医疗器械消费行为倾向量表的信度和效度检验

目的建立并检验居民及医务人员医疗器械消费倾向量表。方法结合国内外文献研究及我国实际情况,制定医疗器械消费倾向量表;以辽宁省9个示范区1805名居民及各级医疗机构2800名医务人员为调查对象开展问卷调查。结果居民及医务人员医疗器械消费倾向量表Cronbach’sα系数分别为0.757和0.688。探索性因子分析结果表明居民及医务人员量表均得到2个公因子,溢价倾向维度与品牌倾向维度归于同一个因子,其余结果均符合原设计。结论本研究建立的居民及医务人员医疗器械消费倾向量表,经调整后分为品牌倾向与重购意向两个维度,量表合理性良好,具有良好的信度及效度水平。     

利用HIS—Star软件加强电子病案首页管理提高统计信息质量

电子病案首页填写是否完整、准确、规范是影响统计数据质量的最主要因素。完善电子病案首页管理,确保统计数据质量的准确性和完整性。     

阿尔茨海默病大鼠模型PET在体成像研究

目的研究18F-FDG及Aβ蛋白显像剂(4’-schiff-O[11CH3])PET成像技术在判别阿尔茨海默病大鼠模型中的作用。方法对10只注射Aβ1～40复制阿尔茨海默模型大鼠及10只注射生理盐水对照大鼠行HE染色及刚果红染色,检测大鼠脑内病理学改变。用18F-FDG及4’-schiff-O[11CH3]PET显像技术在体观察2组大鼠脑内Aβ蛋白分布及葡萄糖代谢情况。结果模型组大鼠海马出现神经元减少并形成淀粉样斑块。模型组PET显像可见注射侧海马葡萄糖代谢减低及4’-schiff-O[11CH3]摄取增加。对照组仅见轻微神经元损伤,PET显示葡萄糖代谢轻度减低。结论18F-FDG及4’-schiff-O[11CH3]PET显像结合行为学及病理学观察可作为检测模型成功与否的方法之一。     

血栓素B2的高效液相荧光测定及刺五加提取物的抗血小板作用

本文在Turk及Wintersteiger荧光衍生实验的基础上,建立了反相HPLC法测定血小板TXB₂含量的方法.血小板TXB₂用Sep-PakC₁₈提取,在冠醚和碳酸钾存在下,BrMmc与TXB₂的羧基反应生成BrMmc-TXB₂。然后经Zorbax-ODS柱(250mm×4.6mm,5μm)分离,测定荧光强度(E×345,Em405)。流动相为乙腈:水:磷酸(60:40:0.1V/V),流速1ml/min.BrMmc-TXB₂的分离在20min内完成。TXB₂的含量用外标法定量,检测限15ng。体外实验刺五加提取物(0.275～2.2mg/mlPRP)对AA、ADP诱导的家兔血小板聚集有明显的抑制作用,并能抑制AA诱导的血小板TXB₂的生成。静脉注射(120mg/kg)对AA、ADP诱导的聚集也有抑制作用。     

妊娠合并卵巢肿瘤的诊治

目的探讨妊娠合并卵巢肿瘤的临床特点及诊断治疗方法。方法回顾性分析2002年1月至2009年12月首都医科大学宣武医院59例妊娠合并卵巢肿瘤患者的临床资料。结果妊娠合并卵巢良性肿瘤,以成熟性畸胎瘤为主,占89%,多数患者无明显症状。结论超声诊断有一定局限性;选择正确的治疗方法进行治疗不影响妊娠结局;血清CA199在卵巢成熟性畸胎瘤的诊断中有一定的参考价值;血清CA125在妊娠早期对卵巢良恶性肿瘤的鉴别是否有意义有待于进一步探讨。