华法林联合肝素对瓣膜置换术后患者微循环的影响

目的:研究华法林联合肝素对瓣膜置换术后患者微循环的影响,评价其有效性及安全性。方法:选择2014年1月-2015年6月我院收治的瓣膜置换术患者60例,随机分为实验组和对照组,每组30例。对照组患者瓣膜置换术后第二天口服华法林治疗,实验组患者瓣膜置换术后当天即皮下注射低分子肝素钙,术后第二天口服华法林抗凝治疗。两组患者均于术后7 d、14 d空腹取外周静脉血,检测红细胞比容、血沉、全血还原比粘度、血浆比粘度以及红细胞聚集指数。结果:与对照组相比,实验组患者术后7d、14 d血沉值、全血比粘度水平、全血还原比粘度水平、血浆比粘度和红细胞聚集指数均显著降低,差异具有统计学意义(P0.05);两组患者术后7 d、14 d血细胞比容比较,差异无统计学意义(P0.05)。结论:和单独应用华法林相比,瓣膜置换术后采用联合应用华法林及肝素能更好改善患者微循环,值得临床推广。     

Surface plasmon resonance sensor for heparin measurements in blood plasma

Surface plasmon resonance (SPR) was used as an affinity biosensor to determine absolute heparin concentrations in human blood plasma samples. Protamine and polyethylene imine (PEI) were evaluated as heparin affinity surfaces. Heparin adsorption onto protamine in blood plasma was specific with a lowest detection limit of 0.2 U/ml and a linear window of 0.2–2 U/ml. Although heparin adsorption onto PEI in buffer solution had indicated superior sensitivity to that on protamine, in blood plasma it was not specific for heparin and adsorbed plasma species to a steady-state equilibrium. By reducing the incubation time and diluting the plasma samples with buffer to 50%, the non-specific adsorption of plasma could be controlled and a PEI pre-treated with blood plasma could be used successfully for heparin determination. Heparin adsorption in 50% plasma was linear between 0.05 and 1 U/ml so that heparin plasma levels of 0.1–2 U/ml could be determined within a relative error of 11% and an accuracy of 0.05 U/ml.     

低分子肝素钙联合阿加曲班应用于急性脑梗死抗凝治疗对患者疗效和预后的影响

目的:探讨低分子肝素钙联合阿加曲班应用于急性脑梗死(ACI)抗凝治疗对患者临床疗效和预后的影响。方法:选取我院于2016年1月至2018年12月期间收治的120例ACI患者,采用随机数字表法分为研究组与对照组各60例,对照组采用低分子肝素钙进行抗凝治疗,研究组在对照组基础上联合阿加曲班治疗,对比两组治疗前后的神经功能缺损评分(NIHSS)、巴氏指数(BI)、纤维蛋白原(FIB)、血小板计数(PLT)、血浆黏度值、血清一氧化氮(NO)、一氧化氮合酶(NOS)、血浆内皮祖细胞(EPCs)及患者的预后。结果:治疗14 d后,两组NIHSS评分、血浆黏度值降低,且研究组低于对照组(P0.05),BI评分、NO、NOS、EPCs升高,且研究组高于对照组(P0.05)。治疗14 d后,两组FIB、PLT均较治疗前降低(P0.05),但两组比较无统计学差异(P0.05)。研究组的预后良好率为60.00%,显著高于对照组的41.67%(P0.05)。结论:低分子肝素钙联合阿加曲班应用于ACI抗凝治疗的临床效果较好,可改善患者血管内皮活性和预后,促进患者神经功能的恢复,降低血液黏度。     

HUMORAL RHEOLOGY : I. VISCOSITY STUDIES AND ANOMALOUS FLOW PROPERTIES OF HUMAN BLOOD SYSTEMS WITH HEPARIN AND OTHER ANTICOAGULANTS

1. A modified falling ball viscometer (rolling ball viscometer) for blood and other humors is presented. It is capable of easily measuring flow properties at several stresses, as is required to define satisfactorily the properties of anomalous flow systems. At high shearing stresses, apparent specific viscosity values of 2.5 + are observed, corresponding to 2.2 ±0.2 reported as possible with the biological viscometer of Whittaker and Winton. 2. Previous references to the anomalous flow properties of blood were verified. It was demonstrated that these systems conform to the Bingham concept of anomalous flow. To define completely the flow properties of such systems it is necessary to make determinations at at least two shearing stresses, preferably more. Data are reported for the pseudoviscosity and yield value, the latter being possibly the most specific property of the three bloods studied. 3. Heparin in increasing amounts tended to decrease the apparent viscosity, pseudoviscosity, and yield value of blood. Similar increases of heparin also reduced the viscosites of the serum and plasma. 4. The ratio of the apparent viscosity of blood and its plasma was found to be reasonably constant as reported by Trevan. However, as the apparent viscosity is a function of the shearing stress, it is believed that the relationship for the calculations of corpuscular concentrations, such as the Whittaker and Winton modification of the Hatschek formula, is specific for the instrument and conditions of tests by which it was determined. 5. Heparinized blood was found to exhibit thixotropy, dilatancy, and age-hardening phenomena.     

Influences of heparin on ACTH distribution and immunoreactivity in plasma of the rat. In vivo and in vitro studies

1. Blood samples from non-pregnant female rats were incubated in vitro with porcine 125I-ACTH, and the corresponding plasmas were chromatographed on fine Sephadex G 50. When heparin was added in vivo or in vitro, almost all the radioactivity appeared in the void volume of the columns; the same was observed when labelled ACTH was added to heparin-containing saline. In contrast, when NaCl instead of heparin was added to the blood in vivo as well as in vitro, almost all the plasma radioactivity was eluted later, with 125I-ACTH. 2. When labelled ACTH was i.v. administered to pregnant females, it was eluted in the void volume in the presence of heparin, and further down in its absence. 3. The same plasma samples from non-stressed or ether-stressed females were radioimmunoassayed for ACTH, with and without heparin. The degradation of ACTH was greater in the presence of heparin, and plasma ACTH concentration was understimated for low blood levels of heparin (5 UI/ml or less) and in contrast overestimated for high ones (25 or 50 UI/ml). 4. In conclusion, the reported data clearly demonstrated firstly that heparin added to rat blood traps ACTH molecules, promoting the formation of aggregates with apparent height molecular weight; secondly that heparin interferes with the direct radioimmunoassay of ACTH in the plasma.     

Effect of plasma exchange on blood viscosity and cerebral blood flow.

The effects of plasma exchange using a low viscosity plasma substitute on blood viscosity and cerebral blood flow were investigated in eight subjects with normal cerebral vasculature. Plasma exchange resulted in significant reductions in plasma viscosity, whole blood viscosity, globulin and fibrinogen concentration without affecting packed cell volume. The reduction in whole blood viscosity was more pronounced at low shear rates suggesting an additional effect on red cell aggregation. Despite the fall in viscosity there was no significant change in cerebral blood flow. The results support the metabolic theory of autoregulation. Although changes in blood viscosity appear not to alter the level of cerebral blood flow under these circumstances, plasma exchange could still be of benefit in the management of acute cerebrovascular disease.     

Cardiac mechanoenergetic cost of elevated plasma viscosity after moderate hemodilution

The purpose of this study was to investigate how plasma viscosity affects cardiac and vascular function during moderate hemodilution. Twelve anesthetized hamsters were hemodiluted by 40% of blood volume with two different viscosity plasma expanders. Experimental groups were based on the plasma expander viscosity, namely: high viscosity plasma expander (HVPE, 6.3 mPa?·?s) and low viscosity plasma expander (LVPE, 2.2 mPa?·?s). Left ventricular (LV) function was intracardiacally measured with a high temporal resolution miniaturized conductance catheter and concurrent pressure-volume results were used to calculate different LV indices. Independently of the plasma expander, hemodilution decreased hematocrit to 28% in both groups. LVPE hemodilution reduced whole blood viscosity by 40% without changing plasma viscosity, while HVPE hemodilution reduced whole blood viscosity by 23% and almost doubled plasma viscosity relative to baseline. High viscosity plasma expander hemodilution significantly increased cardiac output, stroke volume and stroke work compared to baseline, whereas LVPE hemodilution did not. Furthermore, an increase in plasma viscosity during moderate hemodilution produced a higher energy transfer per unit volume of ejected blood. Systemic vascular resistance decreased after hemodilution in both groups. Counter-intuitively, HVPE hemodilution showed lower vascular resistance and vascular hindrance than LVPE hemodilution. This result suggests that geometrical changes in the circulatory system are induced by the increase in plasma viscosity. In conclusion, an increase in plasma viscosity after moderate hemodilution directly influenced cardiac and vascular function by maintaining hydraulic power and reducing systemic vascular resistance through vasodilation.     

Effect of anticoagulants on the activity of trypsin-like proteinases in human blood plasma

Influence of some anticoagulants (heparin, sodium citrate, their mixture) on blood trypsin-like proteinases activity was examined. The activity was determined using synthetic substrate N-alpha-benzoyl-L-arginine-p-nitroanilide. It was shown that heparin greatly activated blood trypsin-like proteinases (at heparin concentration 5 unit/ml of blood, the enzyme activity in plasma was about 10 times higher than the activity in serum). Heparin added to serum caused the activation effect too, maximum of activation was reached at heparin concentration in serum 800 unit/ml, following increase of heparin concentration did not led to the activity change. Sodium citrate had no significant effect both on the trypsin-like proteinases activity and on the activation effect of heparin. It was found that investigated anticoagulants did not affect blood antitryptic activity.     

Effects of blood viscosity on renin secretion.

The effects of alterations in blood and plasma viscosities on plasma renin activity (PRA) were studied in dogs anesthetized with pentobarbital. Blood viscosity was altered by changing the hematocrit (Hct) level by isovolemic exchange using packed red blood cells or plasma. Plasma viscosity was elevated by isovolemic exchange using Hct-matched blood with high molecular weight dextran (Dx, mean m.w. approximately 450,000) dissolved in plasma. Following control measurements of plasma and blood viscosities, plasma [Dx], PRA, Hct and hemodynamic functions, the dog was subjected to isovolemic exchange transfusions to either alter the Hct or administer the Dx. Various measurements were repeated 40-60 min after each exchange. Arterial pressure and renal blood flow remained relatively constant after exchanges; increases in plasma and blood viscosities were accompanied by a decrease in renal vascular hindrance (vasodilation) to keep the renal flow resistance at control level. PRA rose with increases in plasma [Dx] and viscosity, and the rise in PRA was best correlated with the decrease in renal hindrance. The changes in PRA and renal hindrance have the same regression line whether blood viscosity was altered by Hct variation or Dx administration. The results indicate that increases in viscosity cause a compensatory vasodilation of renal vessels to cause renin secretion.     

D- 二聚体、血流变学指标对结缔组织病患者诊疗价值研究

目的:探讨分析结缔组织病合并多器官损害患者D-二聚体(DD)、血流变学指标(血浆纤维蛋白原/血浆纤维蛋白降解产物FDP、全血黏度、血浆黏度)水平及指标变化对结缔组织病合并多器官损害患者病情活动期的诊疗价值。方法:本研究共纳入120例患者,其中活动组患者60例,病情缓解组患者60例,分别测定二组患者DD、血流变学指标水平,并采用t检验、灵敏度与特异度进行统计学分析与描述。结果:与缓解组比较,活动组DD、纤维蛋白降解产物(FDP)、全血黏度、血浆黏度、γ球蛋白、补体C4、ESR均具有统计学差异(P0.01),补体C3组间差异也具有统计学意义(P0.05)。各指标对于疾病活动性诊断的准确性,其DDFDP补体C3、C4γ-球蛋白血浆黏度全血黏度ESR。结论:结缔组织病合并多器官损害患者,其纤溶水平、微循环状态与疾病活动密切相关。     

Rheological characteristics of the blood in long-term and quick adaptation to muscle loads

It was established in chronic experiments on 26 dogs that long-term adaptation to regular muscular activity caused a 19.6-46.1% decrease in blood viscosity. Hematocrit was lowered and red cell deformability improved. A correlation was observed between blood viscosity and its oxygen transport function. As a result of muscular training the role of plasma protein in blood viscosity increased and that of red cells declined. Single muscular activity produced a 48.2-81% increase in blood viscosity, while plasma viscosity remained unchanged. Trained animals had lower absolute values of blood viscosity even at the time of muscular effort as compared to those in untrained animals at rest.     

Heparin removal from blood using poly(L-lysine) immobilized hollow fiber

Based on the negative charge density characteristics of heparin, an affinity adsorption technique has been developed for the removal of heparin from blood. Poly(L-lysine) . HBr (PLL . HBr), a polycation, was immobilized with the help of cyanogen bromide (BrCN) onto poly(ethylene-vinyl alcohol) (PEVAL) copolymer coated polyethylene (PE) hollow fibers. Heparin bound rapidly onto PLL . HBr imobilized surface in buffer, plasma, and blood. The heparin binding capacity of PLL immobilized surface increased sevenfold as compared to a non-PLL-treated control. When heparinized blood was recirculated through a PLL immobilized PEVAL hollow fiber cartridge, the anticoagulant activity of heparin decreased by 85% from initial activity in 25 min. Moreover, circulation of blood through PLL immobilized hollow fiber did not show any adverse effects; no hemolysis was observed and no significant loss of plasma proteins was noted during the heparin removal process. These results suggest that PLL immobilized surface may be utilized for rapid and effective removal of heparin from blood. (c) 1992 John Wiley & Sons, Inc.     

On the low viscosity blood of two cold water,marine sculpins

Summary The viscosities of blood from shorthorn sculpin (Myoxocephalus scorpius), longhorn sculpin (Myoxocephalus octodecemspinosus) and winter flounder (Pseudopleuronectes americanus) were compared using a cone-plate viscometer. Both species of sculpin were almost identical with respect to blood and plasma viscosity at the temperatures (0 and 15°C) and shear rates (2.3–90/s) examined. In contrast, the viscosities of winter flounder blood and plasma were considerably greater than those observed in the sculpins. This difference in blood viscosity between the shorthorn sculpin and the winter flounder persisted over the hematocrit range of 0 to 40% red blood cells. The viscosity of the plasma and the interactions between plasma proteins and red blood cells appeared to be the major reasons for the relatively high viscosity of the flounder blood. Although a proportion of the flounder blood viscosity was attributable to fibrinogen, other plasma proteins also appeared to play a significant role. The relatively low blood viscosity of the sculpin species may confer a circulatory advantage during periods of low water temperatures.     

Aqueous lithium heparin is a superior anticoagulant to solid heparin for blood collection from the retro-orbital sinus of rats

Blood specimens from the retro-orbital sinus of 80 Sprague Dawley rats were collected into tubes containing lithium heparin either as a solid or an aqueous solution. Plasma was separated for blood chemistry analysis. Twenty-eight blood specimens collected into tubes containing solid heparin were clotted and eight specimens were partially clotted making these samples unsuitable for some analyses. None of the specimens collected into heparin solution showed any evidence of clotting. The variances of lactate dehydrogenase and alpha-hydroxybutyrate dehydrogenase activities in plasma prepared with solid heparin were significantly greater than those prepared with heparin solution. Lithium heparin solution is now used routinely in our laboratory.     

Blood viscosity parameter correlation with types of leukemia.

We investigated the hemorheological, hematological and biochemical parameters in 30 cases of acute lymphocytic leukemia (ALL), 21 cases of acute myelogenous leukemia (AML) and 30 cases of chronic myelogenous leukemia (CML). The parameters studied include whole blood viscosity, plasma viscosity, erythrocyte sedimentation rate (ESR), red cell filterability, hematocrit, platelet count and aggregation, fibrinogen, hemoglobin, leucocyte count, bleeding time and lactate dehydrogenase activity (LDH). In the cases of ALL we observed significant decrease in whole blood viscosity, hemoglobin, hematocrit and platelet count but an increase in plasma viscosity, fibrinogen, bleeding time and LDH activity. In the cases of AML, we observed increase in whole blood viscosity, plasma viscosity, ESR, fibrinogen, leucocyte count, bleeding time and LDH activity but decrease in the hemoglobin, hematocrit and platelet count. In the cases of CML, we observed an increase of whole blood viscosity, plasma viscosity, ESR, fibrinogen elevation but decreases in bleeding time. In all cases, red cell filterability was unaffected.     

Non-Newtonian rheology of leukemic blood and plasma: are n and k parameters of power law model diagnostic?

When discussing the rheological properties of normal and leukemic blood it must be considered that blood is a suspension of cells in aqueous solution which is also known as plasma. Whole blood viscosity and plasma viscosity were determined by Rheometer LS30 which allows measuring whole blood and plasma viscosity in the middle and low shear rate ranges. The measurements of the viscosity showed that whole blood and plasma behave as non-Newtonian power law fluid. The values of n (non-Newtonian index) and k (consistency index) of power law fluid were calculated for both leukemic blood and plasma samples. The importance of this phenomenon for the micro-circulation is discussed.     

Risk factors evaluation in some cardiovascular diseases

Cardiovascular risk factors are associated with limitations of blood fluidity. Rheological behaviour of blood in transient flow may result from the internal organization, which in turn depends upon many parameters, which may be considered as possible elements of a profiling algorithm for diagnostic and prognostic values in various pathophysiological states. This study was designed to investigate haemorheological parameters in patients being treated for hypertension, coronary heart disease and myocardial infarct. On the basis of plasma viscosity, whole blood viscosity, haematocrit, red cell aggregation and red cell deformation, the risk was evaluated. In cases of hypertension there was a significant rise in plasma viscosity, whole blood viscosity, red cell aggregation and a fall in red cell deformability. In cases of coronary disease, plasma viscosity and red cell aggregation was increased, while in patients with myocardial infarcts, where the degree of severity is greater it was found that there was a significant rise in both plasma and whole blood viscosity. Haematocrit values were unaffected in all three groups.     

Distribution of body fluid and change of blood viscosity in broilers (Gallus domesticus) under high temperature exposure

This study was to observe the distribution of body fluid by measuring blood volume, extracellular and intracellular fluid volumes and total body water under heat exposure, in order to clarify the mechanism of decrease in whole blood viscosity of the heat-exposed broilers. Whole blood viscosity, haematocrit, plasma protein concentration, plasma osmolality and extracellular fluid volume decreased during high temperature exposure, while plasma and blood volumes increased. No significant changes were found in both intracellular fluid volume and total body water between thermoneutral and high temperature exposure. These results indicate the decreased whole blood viscosity is induced by a plasma volume expansion, in which water may come from the interstitial space and alimentary tract, under heat exposure.     

Studies on platelet functions in hirudin plasma

Comparative studies on platelet responses in citrated, hirudin and heparin plasma were carried out. The adhesion of 111In-labelled rabbit platelets to the subendothelium of rabbit aorta was more pronounced in hirudin plasma than in heparin and citrated plasma. There were no significant differences in the collagen-induced aggregation and secretion of 14C-serotonin of human blood platelets in the three plasma samples. The extent of the ADP-induced aggregation was nearly the same in the three plasma samples, however, the aggregation was reversible in hirudin plasma. Adrenaline induced a small primary aggregation in hirudin plasma whereas in citrated and in heparin plasma the aggregation was a biphasic one. Secretion of 14C-serotonin induced by ADP or adrenaline occurred in citrated plasma only. Hirudin proved to be a suitable anticoagulant for studying platelet functions at physiological calcium concentrations.     

Hemodynamic effects of lipids in humans

Evidence suggests lipid abnormalities may contribute to elevated blood pressure, increased vascular resistance, and reduced arterial compliance among insulin-resistant subjects. In a study of 11 normal volunteers undergoing 4-h-long infusions of Intralipid and heparin to raise plasma nonesterified fatty acids (NEFAs), we observed increases of blood pressure. In contrast, blood pressure did not change in these same volunteers during a 4-h infusion of saline and heparin. To better characterize the hemodynamic responses to Intralipid and heparin, another group of 21 individuals, including both lean and obese volunteers, was studied after 3 wk on a controlled diet with 180 mmol sodium/day. Two and four hours after starting the infusions, plasma NEFAs increased by 134 and 111% in those receiving Intralipid and heparin, P < 0.01, whereas plasma NEFAs did not change in the first group of normal volunteers who received saline and heparin. The hemodynamic changes in lean and obese subjects in the second study were similar, and the results were combined. The infusion of Intralipid and heparin induced a significant increase in systolic (13.5 +/- 2.1 mmHg) and diastolic (8.0 +/- 1.5 mmHg) blood pressure as well as heart rate (9.4 +/- 1.4 beats/min). Small and large artery compliance decreased, and systemic vascular resistance rose. These data raise the possibility that lipid abnormalities associated with insulin resistance contribute to the elevated blood pressure and heart rate as well as the reduced vascular compliance observed in subjects with the cardiovascular risk factor cluster.