Changes in intravascular fluid composition following blood replacement with perfluorocarbon emulsion in the rat

Summary The effects of near total blood replacement with the proprietary perfluorocarbon emulsion, Fluosol-DA, have been examined in conscious, chronically catheterized rats. Animals survived for up to 48 h with a haematocrit of <2%. No overt changes in cardiovascular or respiratory functions occurred during blood replacement but thereafter, animals showed a progressive deterioration of haemodynamic control. Changes in intravascular fluid composition during and following exchange-transfusion have been monitored and the extent to which these changes could have contributed to the eventual disruption of homeostasis is discussed.Abbreviations PFC perfluorocarbons - RES reticuloendothelial system     

Regulation of blood services in Africa

Blood and blood products save lives and are a part of the WHO Essential Medicines List. Access to safe and quality-assured blood and blood products are essential for health systems strengthening and it is a global concern. Their use is associated with infectious and immunologic risks. At global level, many resolutions have been adopted by the World Health Assembly that urged Member States to ensure regulatory control of access to quality-assured blood and blood products along the entire transfusion chain. The WHO has also developed an action framework to advance universal access to blood. As part of the implementation of these resolutions and guidelines, the WHO Regional Office for Africa and some partners provided support to countries in the region to strengthen their capacity to establish an effective blood regulatory system through organization of regional training workshops on blood regulation, benchmarking of blood regulatory systems, internship at Paul Ehrlich Institut and establishment of the African Blood Regulators Forum. The current status of blood regulation reveals that there are weak transfusion legislation and blood regulatory systems in most African countries, since many national blood transfusion services still rely on self-regulation. However, the national regulatory authorities have reached the maturity level 3 in two countries (Ghana and Tanzania), but only the experience from Ghana has been described in this paper. Like in other low- and middle-income countries, the regulatory systems for associated substances and medical devices including IVDs are not well established in the African region. Misunderstanding by different stakeholders, lack of legislation that provides legal basis, weak capacity and insufficiency of resources are main challenges facing countries to establish an effective national blood regulatory system. To address these challenges, strong advocacy with governments and collaboration with partners are needed to strengthen national blood regulatory systems.     

后置导轮对人工轴流心脏泵的影响分析

后置导轮在人工轴流心脏泵工作过程中具有至关重要的作用,为了研究其对心脏泵的影响,利用计算流体力学(CFD)的方法,详细分析了后置导轮对人工轴流心脏泵工作情况的影响。通过对轴流心脏泵内整个流场的数值模拟,讨论了引入后置导轮后,轴流心脏泵的压强增量、效率、工作情况以及流体受力等重要参数的变化。计算结果表明:引入合适的后置导轮能够改善流场分布,限制出流的速度方向,提供足够的静压增量,有利于传输血液,同时基本保持了泵的效率不降低。因此,在人工轴流心脏泵设计过程中引入后置导轮是必要的,但需要对后置导轮的参数进行严格的分析。     

Artificial liver support at present and in the future

Liver failure is a fatal disease. Liver transplantation is the only established treatment for liver failure; however, donor shortages remain problematic. In the United States and Europe, artificial livers as a bridge to liver transplantation are being considered. In Japan, we have taken a different approach to the treatment of end-stage liver diseases because of the characteristics of the health-care insurance system, regulated by the government. Furthermore, cadaveric liver transplantations are unsuited to the social mores of Japanese culture. Practically speaking, we believe that plasma exchange (PE) and continuous hemodiafiltration (CHDF) are the most effective therapies for the treatment of liver failure, although randomized controlled studies are needed to determine their effects. Overall, we believe that the first line of treatment for liver failure should be PE and CHDF, and the second line should be bioartificial liver support. In the near future, we hope that both gene therapy and regenerative medicine will contribute to the development of a functional artificial liver.     

小口径人工血管及制备方法的研究进展

血管移植是治疗心血管疾病的主要手段之一。小口径人工血管的研发也成为近十年来的研究热点。本文从制备小口径人工血管的材料和方法方面,首先简述了人工合成材料和天然生物材料,然后介绍了近些年来浸渍 沥滤法、混凝法、去细胞组织复合法、静电纺丝法、旋转曝光法、组织工程血管支架法及3 D快速成型技术应用等的研究进展。阐述了作为小口径人工血管的各种材料和制备方法的特点,为理想的小口径人造血管进一步的发展提供了一定的参考。最后对小口径人工血管发展前景做了展望。     

小口径人工血管的研究现状及展望

近年来,由于心血管疾病发生率逐渐上升,临床上对再生血管的需求日益增加。目前,大口径人工血管(直径>6 mm)已成功应用于临床,小口径人工血管(直径<6 mm)由于血栓形成、内膜增生、炎症反应和顺应性差导致血流动力学改变等原因,使其移植后远期通畅率低,距离临床应用尚有一段距离。其中,快速内皮化、抑制血栓形成及与自体血管相匹配的顺应性仍是解决问题的关键。本文简述制备小口径人工血管常用材料及技术的特点,重点讨论提高人工血管生物相容性和顺应性的策略,并对未来的研究工作进行展望。     

The economics of blood transfusion in the 21st century

In the coming years, blood banking will face a number of big challenges in which economic analysis may help find the optimal solution. Pressures to curb cost increases without reducing perceived quality will shift the emphasis from excellence to efficiency. The financial incentive structure that allows costly but low effective technologies to be widely adopted will need to be revised and reshaped. This will require introducing regulated competition between blood suppliers and a closer alignment between the decisions on enforcing new safety measures and the economic consequences of the decisions. On the other hand, if blood shortages become more frequent and severe, as predicted by some experts, property rights on human blood will need to be assigned and fairly compensated, what will require resolving first the ethical issue that accompanies remunerated blood donation. Finally, availability at the bedside of an effective and safe blood substitute will help alleviate blood shortages, but may also profoundly disturb the very way blood banks finance their operations.     

Flat crossed-coil detector for blood flow measurement using nuclear magnetic resonance

A new flat crossed-coil nuclear magnetic resonance (n.m.r.) detector can be used to measure flood flow at many regions of the body, is introduced. It is compared, bothin vitro andin vivo, with the already proven cylindrical crossed-coil n.m.r. detector. Both detectors use a single high-field homogenous magnet. A single-sideband receiver reduces the effect of transmitter leakage into the receiver coil to allow the use of a high-level transmitter field. Preliminary application of the flat crossed-coil detector to the detection of cerebral blood flow is presented.     

Platelets and extracorporeal circulation

Extensive contact between blood and the synthetic surfaces of an extra-corporeal circuit causes thrombocytopenia, release of platelet granular contents, initiation of thromboxane synthesis, disruption of subcellular architecture and loss of platelet sensitivity to standard platelet agonists. All too frequently, these adverse platelet alterations are reflected in a prolongation of the post-operative bleeding time and excessive blood loss which precludes implementation of long-term circulatory assist devices. Unfortunately, a truly biocompatible material does not exist and efficiency of gas transport demands haemodynamic designs which actually promote platelet injury. Although manipulation of surface properties and mechanical improvements in circuitry have managed to reduce platelet-surface interactions, the ultimate potential of these manoeuvres may be limited. Synthetic surfaces and soluble agonists, however, appear to modulate similar pathways suggesting that temporary platelet inhibition might provide significant protection by preserving the morphological and functional integrity of circulating platelets during contact with extracorporeal circuits.     

Physiological quality assessment of stored whole blood by means of electrical measurements

The physiological parameters of blood such as extracellular Na⁺, K⁺, Cl⁻, pH, 2,3-DPG and ATP and the complex electrical impedance were measured using whole blood samples from 31 male donors (21 donors form the training set and ten donors were used for testing), on the 0th, 10th and 21st day of blood bank storage. During storage, while the extracellular fluid resistance (R _e) and the intracellular fluid resistance (R _i) decreased progressively with time, the effective cell membrane capacitance (C_m) has increased. Blood bank storage resulted in a rise in K⁺ and a fall in Na⁺, Cl⁻, pH, 2,3-DPG and ATP. Accordingly, all electrical parameters correlated with Na⁺, K⁺, Cl⁻, pH and ATP, at varying levels. By applying the multi-regression analysis, it was demonstrated that R _i, R _e and especially C _m were appropriate for the assessment of Na⁺, K⁺, Cl⁻, pH and ATP until the 21st day of storage.     

老年髋部骨折围手术期失血量的临床观察

目的通过观察髋部骨折围手术期血红蛋白水平改变,总结髋部骨折患者围手术期隐形失血量、总失血情况,探讨围手术期失血量的危险因素。方法选择北京市顺义区医院骨科2011年12月至2013年12月老年髋部骨折患者,记录患者一般情况,包括性别、年龄、并发症、骨折类型,手术方式（分别按照空心钉、关节置换、动力性髋螺钉和髓内钉的标准流程操作）、抗凝药物使用情况、出血量、手术时间等,根据患者血红蛋白水平波动、输血量计算患者隐形失血量、总失血量,通过方差分析及多因素线性分析计算围手术期间总失血量的独立危险因素。结果 2011年12月至2013年12月共有161例老年髋部骨折患者入选,经单因素方差分析及多因素线性回归分析,发现服用抗凝药物（均P=0.000）、手术方式（P=0.000,P=0.004）是围手术期出血量较多的独立危险因素。结论老年髋部骨折围手术期隐形失血量远远大于术中出血量,髓内钉术中出血量较关节置换、动力性髋螺钉（DHS）系统少,但隐形失血量、总失血量较其他三种手术方式明显增多,此外,服用阿司匹林等抗凝药物可增加术中出血量、隐形失血量及总失血量。     

人工血管基因修饰的研究进展

人工血管基因修饰是利用基因工程技术将目的基因转入人工血管内衬的内皮细胞中 ,使之分泌抗凝分子等 ,以增强人工血管的抗血栓能力 ,延长其体内通畅时间。至今 ,已先后将β- gal、t- PA等分子基因修饰人工血管获得成功 ,其体内外实验也初步显示了这一技术应用的良好前景和巨大潜力。基因修饰技术的应用将给人工血管带来崭新的变化 ,使之成为一种非常有前途、具有重要应用价值的治疗工具和手段     

用于人工胰腺的血糖闭环控制方法研究进展

糖尿病患者的科学诊疗需要频繁进行血糖检测进而指导胰岛素注射。因此,具有血糖连续监测功能的闭环胰岛素泵系统（亦称人工胰腺）,是医疗行业和众多学者急迫研究的目标。其中,具有时滞特点的血糖闭环控制问题,是人工胰腺系统开发过程中的关键与亟须突破的难点之一。文中首先分析介绍了人工胰腺系统组成结构与控制特点;然后对目前血糖闭环控制方法的研究进展进行了综述,从是否适应人工胰腺实际工作特点的角度对比分析各种控制方法的特点;再后从临床应用方面总结讨论了各种血糖控制算法应用进展情况,其中模型预测、比例-积分-微分（PID）与模糊控制是目前已开展临床试验研究并取得较好效果的血糖控制算法;最后分析指出,血糖控制算法的芯片植入及与之相关的算法精简优化、进餐预测、控制安全等,是需要未来进一步关注的问题。     

The separate and combined influences of common carotid occlusion and nonhypotensive hemorrhage on kidney blood flow

The separate and combined effects of bilateral common carotid occlusion (C.C.O.) and hemorrhage on renal blood flow (R.B.F.) were studied in 11 unanesthetized dogs.C.C.O. increased arterial blood pressure (4.4 kPa; 33 mm Hg) and heart rate (10 beats/min) while R.B.F. remained unchanged. When kidney perfusion pressure was maintained at its resting level during C.C.O. (implanted pneumatic cuff) there was also no change in R.B.F.After cutting the aortic nerves in 2 dogs the increase in blood pressure and heart rate with C.C.O. was greater (10.6 kPa; 80 mm Hg and 72 beats/min); however, there was no change in R.B.F.A blood loss of 16% (13.6 ml/kg) reduced central venous pressure (0.3 kPa; 2 mm Hg), increased heart rate (8–14 beats/min) and decreased arterial mean pressure by a maximum of 0.7 kPa (5 mm Hg) (nonhypotensive hemorrhage, N.H.H.). R.B.F. showed a tendency to rise and 90 min after the onset of bleeding was slightly increased (12% of control).After N.H.H. carotid occlusion had no effect on R.B.F. when kidney perfusion pressure increased; when perfusion pressure was controlled during C.C.O. the maximum observed decrease of R.B.F. was 15 ml/min (5% of control).It is concluded that the control of R.B.F. during the baroreceptor reflex under normovolemia and after a blood loss of 16% in the conscious dog at rest does not involve sympathetic vasoconstrictor effects which result in a significant changes in total blood flow.This study was supported by the German Research Foundation within the S.F.B. 90, Heidelberg     

Application of a Bacterial Artificial Chromosome Modification System for a Human Artificial Chromosome Vector

Exactly controlled conditional gene expressing systems are crucial for genomic functionalresearch, animal transgenesis and gene therapy. Bacterial artificial chromosomes (BACs)are optimal for harboring long fragments of genomic DNA or large cDNA up to 300 kb insize. Therefore, BACs are available to produce transgenic cells and animals for thefunctional studies of genes. However, BAC can insert DNA randomly into the host genome,possibly causing unpredicted expression. We previously developed a human artificialchromosome (HAC) vector from human chromosome 21 using chromosome engineering. The HACvector has several important characteristics desired for an ideal gene delivery vector,including stable episomal maintenance, and the ability to carry large genomic DNAcontaining its own regulatory element, thus allowing physiological regulation of thetransgene in a manner similar to that of the native chromosome. In this study, we developa system fusing BAC library and HAC technology together to allow tight control of geneexpression. This system enables BAC to be cloned into the defined locus on the HAC vectorby the Cre/loxP system. In addition, the genome in the BAC is possible to be engineeredfreely by the BAC recombineering technology. This system is a highly efficient tool forthe rapid generation of stringently controlled gene expression system on the HACvector.     

孕中晚期胎儿血细胞各项参数变化的研究

目的探讨孕中晚期胎儿血细胞各项参数变化规律,了解胎儿血细胞的生成情况,为产前胎儿宫内疾病诊断提供依据。方法采用Bayer ADVIA120全自动五分类血细胞分析仪对249例孕18～39周胎儿脐血血细胞进行以下各项参数的检测:白细胞计数(WBC)、中性粒细胞百分比(NEU%)、淋巴细胞百分比(LYM%)、单核细胞百分比(MON%)、嗜酸性粒细胞百分比(EOS%)、嗜碱性粒细胞百分比(BASO%)、红细胞计数(RBC)、血红蛋白含量(HGB)、红细胞比容(HCT)、红细胞平均体积(MCV)、红细胞平均血红蛋白量(MCH)、平均红细胞血红蛋白浓度(MCHC)、红细胞体积分布宽度(RDW)、血小板PLT等。结果孕中晚期胎儿脐血细胞各项参数中有5项(WBC、NEU%、RBC、HGB、HCT)随着孕周增加而逐渐增大;有2项(MCV、LYM%)随着孕周增加而逐渐减小;还有7项(EOS%、MON%、BASO%、MCH、MCHC、RDW、PLT)在各孕周中变化不大。脐血血细胞各项参数与出生后水平存在显著差异。结论胎儿脐血血细胞成分处在一个动态变化的过程中,不同妊娠阶段胎血中各系血细胞的构成比有较大的差异。因此探讨孕中晚期胎儿血细胞各项参数变化规律有重要意义,在诊断胎儿期贫血,炎症等宫内疾病有重要参考价值。     

Introduction of a program for voluntary blood donations in Iran (blood transfusion status in Iran)

Background A national and well-coordinated system is very effective for blood self sufficiency of a country; this system might be committed to follow all requirements and standards. It should manifest itself strong and well-established in reality and practice so that all potential donors trust it and contribute. Iranian Blood Transfusion Organization (IBTO) is an example of a centralized network with 200 centers in 31 provinces which could only be decentralized in some aspects of blood donor recruitment based on the cultural and regional attributes of the people there. Methods The mission of IBTO is to provide and ensure a safe and adequate blood supply in Iran. Selection of low risk donors in pre-donation consultation and interview sessions based on behavioral, medical and demographic factors has improved the transfusion safety even before specific lab screening tests have been conducted; Standardization of criteria for donor eligibility and exclusion, and donor screening procedures are all priorities and most importantly the collection of all blood donations just from voluntary nonremunerated (VNR) blood donors. In fact, a lot of efforts concentrated on recruitment of VNR donors and to this end the Blood Donor Recruitment and Retention Office was established. A variety of measures were made to increase the number of voluntary regular donors including technical efforts, information dissemination activities, demographic studies, campaigns, awareness raising programs, publicity, publications, commemorative ceremonies and the like. Results The annual donation index in Iran has greatly increased from 0.39 in 1974 to 25.3 in 2010–2011. Accordingly we have been witness to increasing trend of blood donation reaching about 2 million blood units in 2011, all of which obtained from voluntary non-remunerated blood donors with the annual index of 26 per 1000 population. Conclusions It shows that every country based on its needs should establish a very effective and safe program to raise the number of its voluntary blood donors and to this end centralization of activities monitored by a headquarters and implementation of an efficient recruitment plan by which all aspects are covered and monitored: ranging from stages prior to donor selection including campaigns and activities to motivate populations to embark on donation, donor selection, screening, retention, statistical audit, continuous evaluation of donation sites, ease of access to donation centers, demographic attributes, donor reactions, to post donation era to ensure high return rate and so on so forth. All in all, availability and affordability are the issues which should be always guaranteed.     

孕妇外周血中胎儿有核红细胞用于产前诊断的研究进展

本文概述孕妇外周血中胎儿有核红细胞的分离与检测用于产前诊断的研究状况,描述母体外周血中的胎儿细胞的特点,胎儿有核红细胞的富集和分离方法,并对各方法的优点、缺点、病理性妊娠的意义、临床应用、存在的问题及研究进展作一综述。     

Deficient adjustment of cerebral blood flow to cognitive activity due to chronically low blood pressure

The present study aimed to investigate aberrances in the adjustment of cerebral blood flow to cognitive activity due to chronically low blood pressure. By means of transcranial Doppler sonography blood flow velocities in both middle cerebral arteries (MCA) were recorded during the execution of a serial subtraction task in 40 subjects with constitutional hypotension and 40 normotensive control persons. Additionally, blood pressure was continuously monitored. As a main result significant correlations between the task-induced changes in blood pressure and those in MCA blood flow velocities were found in hypotensives, but not in control subjects. The dependence of the regulation of cerebral blood flow on blood pressure points towards deficits in cerebral autoregulation in hypotension. Over the total sample the extent of the task-induced MCA flow velocity increase was positively related to cognitive performance. This underlines the importance of the adjustment of cerebral blood flow to current demands for optimal cognitive functioning.