Deletion polymorphism in the gene for angiotensin-converting enzyme is associated with essential hypertension in men born during the Pacific War

Age is a strong risk factor for hypertension in relation to vascular aging. Additional etiological factors include: lifestyle, genetic factors, and their interactions. The aim of this study is to examine whether an insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme (ACE) gene is associated with essential hypertension in Korean born during the Pacific War. A total of 13,914 healthy subjects (8261 men, 5653 women) aged 20-79 years were examined. Subjects with abnormal renal, thyroid dysfunction, or electrolyte levels were excluded. Logistic regression analysis showed increased risk (OR=1.15; 95% CI, 1.01-1.31) in men, but not in women (OR, 1.06; 95% CI, 0.89-1.26). However, after adjustment for age, obesity, cholesterol, alcohol consumption, and diabetes mellitus, increased risk in men was not significant (OR, 1.13; 95% CI, 0.98-1.42). Analyzed according to birth-year, DD genotype showed increased risk for hypertension in only a subgroup of men (adjusted OR, 1.56; 95% CI, 1.16-2.09; p = 0.001), born during the Pacific War (1941-1945 year). Findings suggest that the ACE DD genotype plays a role in the pathogenesis of essential hypertension, in conjunction with adverse environmental conditions in early life, with sex-related difference.     

Artificial liver support: future aspects

Liver transplantation and blood purification therapy, including plasmapheresis, hemodiafiltration, and bioartificial liver support, are available to treat patients with severe liver failure. The two mainstream systems developed for bioartificial liver support are extracorporeal whole-liver perfusion (ECLP) and the bioreactor system (BIS). We developed a method of plasma cross-perfusion, in which plasma is exchanged between the blood circuit of the patient and that of a hepatic function unit, that is, whole liver or a bioreactor through which immunologically free whole human blood is perfused. From the aspects of efficacy and safety, the best system of bioartificial liver support for clinical use is considered to be ECLP in cross plasma perfusion. However, a social objection about zoonosis has consistently been raised, with controversy surrounding the use of xenogeneic organs for human treatment, and this might be a final obstacle to the development of system efficacy. The combination therapy of hemodiafiltration with the administration of human serum albumin and anticoagulant factors can minimize the economic and medical resource costs through the development of transgenic livestock that secrete human pharmaceuticals systemically. It is possible that this therapy will become the most practical treatment for patients with severe hepatic failure.     

Non-invasive measurement of systolic blood pressure on the arm utilising photoplethysmography: development of the methodology

Photoplethysmography (PPG) can be used to measure systolic blood pressure at the brachial artery. With a specially designed probe, positioned in the most distal position beneath a pressure cuff on the upper arm, this is possible. The distance between the light source (880 nm) and the photodetector was 20 mm. A test was performed on neuro-intensive care patients by determining blood pressure from the PPG curves, and, when it was compared with systolic blood pressure obtained from inserted indwelling arterial catheters, a correlation factor of r=0.95 was achieved. The difference between blood pressure obtained using PPG and invasive blood pressure measurement was 3.9±9.1 mmHg (mean±SD), n=19. The depth to the brachial artery was 13.9±4.1 mm (mean±SD), n=18. A digital PPG system utilising pulsating light was also developed.     

The arteries of the humeral head and their relevance in fracture treatment

Bone vascularisation has gained increased interest in relation to the blood supply of bone fragments during treatment of fractures. In the current study the pattern of vascular supply of the proximal humerus was studied in six cadavers by the corrosion technique. Furthermore, the effect of fractures on the vascular supply was also investigated. In all preparations the intraosseous arteries of the humeral head arose from the circumflex arteries, which surrounded the humerus and dispatched branches towards the proximal end. The main vessel was the branch of the anterior circumflex artery, penetrating the major tubercle in six of six cases. Due to the intraosseous arch shape of this vessel it is referred to as the arcuate artery. Besides other smaller vessels, there was also a vascular network arising from the posterior circumflex artery. Their branches penetrated medially at the cartilage bone interface in five of six preparations. The medial bone arteries appear to gain distinctive importance in humeral head fractures by their impact on the vascularisation of the fracture fragments. After disruption of the arterial supply from the arcuate artery, the vascularisation of the head fragments is most likely ensured by this group of vessels. Therefore, necessary repositioning manoeuvres during open reduction of the fracture should be conducted with care in order to preserve these arteries.     

Effect of Different Blood Cycle Modes on Mass Transfer of Artificial Kidney

INTRODUCTION Hollow fiber dialyzer has been widely applied to hemodialysis and chemicaldialysis process, and it is also called artificial kidney in medical science. There are ofgreat importance to improve the clinical dialysis efficiency by studying the masstransfer performance under different blood cycle modes in artificial kidney. Over the past decades, most models have been developed to describe transportphenomena in artificial kidney, the classical models are double-porous media model…     

血液电频谱特性的测量

为了更全面的了解血液的低频电频谱特性,利用我们所研制的比较法宽频组织、血液电特性检测系统对血液及不同组成、状态等在1Hz～2 0 MHz范围内的幅频特性和相频特性进行了测量。实验结果的进一步分析表明,通过血液电频谱特性的认识,可以帮助我们从一个全新的视角去了解血液、分析血液乃至更微观层次的一些重要性质;同时,指出了现在生物组织、血液等效电模型存在的一些问题及改进的思路。(1)从1Hz～5 KHz范围血液电阻抗下降了99%。(2 )简单的血液电阻、电容等效电路只能是串联等效而非被常用的并联等效。(3)实验表明,血液的等效电路还应进一步分析,因为简单的R、C等效仍有很大误差。(4)为研究探讨血细胞内液电阻、细胞膜电容和细胞外液电阻的三元件模型,在测量时三频率必须非常接近。     

壳聚糖醋酸溶液对凝血作用的研究

研究了不同脱乙酰度和不同分子量壳聚糖醋酸溶液的凝血作用。发现壳聚糖醋酸溶液使抗凝血液中红细胞发生了明显的聚集和变形。通过不同分子量和脱乙酰度壳聚糖的促红细胞聚集实验,证明了低脱乙酰度壳聚糖(60%~70%)使红细胞聚集效果更好,分子量在105~106范围内作用不十分明显。对血液的凝血酶时间(TT)、凝血酶原时间(PT)、活化部分促凝血酶原激酶时间(APTT)和纤维蛋白原浓度(FIB)的测定结果验证了壳聚糖醋酸溶液凝血机理不依赖于血小板和常规“瀑布”凝血机制。     

基于暗视场荧光图像分析的大鼠微血管流速测量系统的建立

将荧光标记的自身红细胞注入SD大鼠体内,在荧光显微镜下观测标记红细胞在大鼠微血管中的流动情况,并通过显微摄像系统将整个过程以视频信号的形式存贮。使用视频采集卡将流速变化过程回放采样,得到暗视场下的荧光图像。然后利用帧图像分离出奇偶场的图像分析方法测定血流速度。在该系统下测量流动小室中荧光小球的流速,得到的测量值与实际值之间的误差小于7%,两者没明显的差异(P>0.05),流速测量的上限为9.6mm/s。并在大鼠微循环障碍研究中,应用此系统得到了血流速度随时间变化的情况。     

视空间认知与脑血流速度的相关性研究

目的:探讨视觉空间认知活动对脑血流速度(CBFV)的影响及性别和任务完成质量对相对的CBFV变化的影响。方法:在完成视觉空间认知活动时及其先前的休息期,对45个正常的志愿者(右利手)用经颅超声多普勒(TCD)监测其双侧大脑中动脉血流速度的变化。结果:完成认知任务时与休息时期相比,所有认知任务的完成均诱导出双侧大脑中动脉血流速度的显著变化(P<0.001),这种变化显示出显著的右侧大脑半球偏侧化(P<0.01)。性别对认知活动所诱导的脑血流速度未产生显著的影响(P >0.05),任务表现质量(得分)对CBFV的变化不产生显著的影响。结论:视觉空间认知活动可诱导CBFV的右侧偏侧化。     

人体血液环形空间螺旋流动研究

在低剪变率条件下人体血液表现为卡森流体,在高剪变率条件下则趋向于牛顿流体。近年,螺旋叶片血泵的研究和应用取得了很大的进展。此研究运用流体力学,对血液在低剪变率及高剪变率两种不同条件下的环形空间螺旋流动性能进行了研究,并推导出速度及流量表达式,分析了各参数对流动性能的影响。