Artificial bone of porous tricalcium phosphate ceramics and its preliminary clinical application

Summary The authors have prepared the artificial bone of porous tricalcium phosphate ceramics according to an appropriate formula and manufacturing technology. Physical and chemical testing shows that it possesses several distinguishing features: the communicating pores and macro/micropores; mean pore size, 380 μm (from 240 μm to 510 μm); porosity, 46.4 %; and compressive strength, 97.4 kg/cm². It consists of CaO (49.09 %) and P₂O₅ (48.84 %). The testing of its biocompatibility shows that it is devoid of systemic or local toxicity, and free of irritation or foreign body response in tissues, and it does not result in hemolysis or mutation. The new bone readily grows into its pores with direct contact to the implanted material. 11 cases of bone defects were treated with this artificial bone with satisfactory results.     

Computer-Assisted Design of an Implantable, Intrathoracic Artificial Lung

Abstract: A semiempirical mathematical model of convective oxygen transport is used to design a new, low pressure loss, implantable artificial lung that could be used as a bridge to lung transplantation in patients with advanced respiratory failure. The mass transfer and flow friction relations pertinent to the design of a cross–flow hollow fiber membrane lung are described. The artificial lung is designed to transfer over 200 ml/min of oxygen at blood flow rates up to 5 L/min. A compact design and a blood-side pressure loss of <15 mm Hg allows the device to be implanted in the left chest without the need for a prosthetic blood pump. Surgical implantation of the artificial lung would require the creation of inflow and outflow anastomoses. Oxygen would be supplied via an external source. Blood properties, operating conditions, and empirically determined mass transfer and flow properties are all specified and input into a computer program that numerically solves the design equations. Computer–generated values for the device frontal area, blood path length, and fiber surface area are thereby obtained. The use of this computer–assisted design minimizes the need for extensive trial–and–error testing of prototype devices. Results from in vitro tests of a prototype implantable lung indicate that the mathematical model we describe is an accurate and useful tool in the design of hollow fiber artificial lungs.     

Transhemation of bovine and human hemoglobin polymers in a simulated circulatory system

All-Union Hematology Research Center, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. I. Vorob'ev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 112, No. 11, pp. 500–501, November, 1991.     

人工肾的最新进展及临床应用

本介绍了人工肾的发展史、临床应用、选购和发展趋势。指出:随着高新技术和透析原理的发展，目前已从血液透析演变为血液净化，拓宽了其临床应用范围。采用组织工程、基因、细胞技术研制的生物人工肾，可望生产出易携带或可移植的生物人工肾，可完全替代肾功能，减少肾衰竭病人的死亡率，成为代肾发展史上的又一个里程碑。     

Development of an open case-based decision-support system for diagnosis in oral pathology

BACKGROUND: Making diagnoses in oral pathology are often difficult and confusing in dental practice, especially for the less-experienced dental student. One of the most promising areas in bioinformatics is computer-aided diagnosis, where a computer system is capable of imitating human reasoning ability and provides diagnoses with an accuracy approaching that of expert professionals. This type of system could be an alternative tool for assisting dental students to overcome the difficulties of the oral pathology learning process. This could allow students to define variables and information, important to improving the decision-making performance. However, no current open data management system has been integrated with an artificial intelligence system in a user-friendly environment. Such a system could also be used as an education tool to help students perform diagnoses. The aim of the present study was to develop and test an open case-based decision-support system. METHODS: An open decision-support system based on Bayes' theorem connected to a relational database was developed using the C++ programming language. The software was tested in the computerisation of a surgical pathology service and in simulating the diagnosis of 43 known cases of oral bone disease. The simulation was performed after the system was initially filled with data from 401 cases of oral bone disease. RESULTS: The system allowed the authors to construct and to manage a pathology database, and to simulate diagnoses using the variables from the database. CONCLUSION: Combining a relational database and an open decision-support system in the same user-friendly environment proved effective in simulating diagnoses based on information from an updated database.     

人工全膝关节置换术治疗膝关节骨关节炎

[目的]评价人工膝关节置换术治疗骨关节炎的临床疗效。[方法]本院自1994年10月～2003年10月采用人工全膝关节置换术治疗膝关节骨关节炎81例（95膝），男10例，女71例；平均年龄65．5岁（50—82岁）；左膝35例，右膝26例，双侧同时置换17例；保留后交叉韧带假体18膝，后方稳定性假体62膝，活动衬垫15膝。[结果]本组平均随访42个月（14—108个月），应用HSS膝关节评分系统进行分析，优：80膝（84．21％），良：10膝（10．53％），可：3膝（3．16％），差：2膝（2．10％）。优良率94．74％。[结论]作者认为人工全膝关节置换术能有效的缓解膝关节骨关节炎的疼痛，改善膝关节功能。正确的选择假体、精细的手术操作和严格的术后康复是保证手术效果的关键。     

心房颤动犬心房肌细胞2型理阿诺受体的分布和表达

目的探讨心房颤动(房颤)时心房肌细胞2型理阿诺受体表达和分布的改变。方法杂种犬10只,分为正常对照组和单纯房颤组,每组5只。单纯房颤组用起搏器进行房颤式快速起搏,起搏频率(500±20)次/min,正常对照组不植入起搏器。24周后取出心脏,用逆转录聚合酶链反应、免疫荧光染色技术检测犬心房肌细胞2型理阿诺受体在mRNA水平的表达和蛋白水平的表达和分布。结果与正常对照组比较,单纯房颤组犬2型理阿诺受体在mRNA和蛋白水平的表达明显低于正常对照组(P<0.05);在细胞质、细胞膜2型理阿诺受体分布均显著减少。结论房颤时心房肌细胞2型理阿诺受体表达下调,2型理阿诺受体可能不是心房肌细胞主要的钙信号调控的受体。     

聚乙烯醇水凝胶髓核的生物力学特性

目的 对一种新型水凝胶人工髓核的生物力学特性进行研究,为将来临床开展人工髓核置换手术提供科学依据。方法 采用7具新鲜标本的L_(4-5)脊柱功能单元进行生物力学实验,在轴向压缩、前屈后伸和左右侧弯等运动工况下,观察正常椎间盘、髓核摘除以及人工髓核植入3种状态下椎间盘高度、应变和位移的变化。结果 与正常椎间盘相比较,髓核摘除后椎间盘的高度和刚度降低,应变和位移加大(P<0.05)。而人工髓核植入后各项指标恢复正常(P>0.05)。结论 这种新型水凝胶人工髓核置换可纠正髓核摘除后的生物力学紊乱,有望进行临床应用。     

Medpor义眼座置入同期放置钛钉治疗眼眶凹陷畸形

目的探讨Medpor义眼座植入同期放置钛钉治疗眼球摘除术后眼眶凹陷畸形的有效性和可行性。方法眼球摘除同期置入Medpor义眼座患者80例，随机分为钛钉Ⅰ期置入组和Ⅱ期置入组，每组各40例。比较两组患者术中、术后出现的并发症和患者对义眼活动度和外观的满意程度。结果40例Ⅰ期置入患者术中有37例在术后2～6周时钛钉尾端自发性暴露，只有3例患者需要剪开结膜使钛钉尾端暴露。术后出现并发症者共37例，占46％：其中Ⅰ期置入组17例，Ⅱ期置入组加例，两者差异无统计学意义（P=0．501）。所有患者对其外观和活动度满意，其中Ⅰ期置入组非常满意36例，比较满意4例；Ⅱ期置入组非常满意34例，比较满意6例，两者差异无统计学意义（P=0．502）。结论Medpor义眼座置入同期放置钛钉治疗眼球摘除术后眼眶凹陷畸形，是一种安全有效的手术方法，同时患者避免了再次手术的痛苦。     

钛种植体－羟基磷灰石早期修复犬下颌骨缺损与骨结合的实验研究

本研究对钛种植体－羟基磷灰石（Ｔｉ－ＨＡ）在早期修复下颌骨缺损中与骨结合的界面形态进行了扫描电镜和Ｘ线能谱观察分析。通过对９只健康狗下颌骨缺损区植入Ｔｉ－ＨＡ２、６及１２周后Ｔｉ－ＨＡ／宿主骨界面及Ｔｉ／ＨＡ界面的扫描电镜观察和Ｘ线能谱分析，结果表明Ｔｉ－ＨＡ植入骨缺损区，不引起正常的骨矿化过程改变，与宿主骨形成骨性结合；Ｔｉ／ＨＡ界面有新骨形成；扫描电镜观察和Ｘ线能谱分析在研究骨缺损修复过程中不同阶段的组织成份的变化是一个重要手段。