Determination of erythrocyte aggregation

One of the most common health criteria--erythrocyte sedimentation rate (ESR)--is considered in the paper. It is shown that the simple model presented, based on the generalized Stokes formula, the blood volume conservation law, and the Smoluchowski theory of particles coagulation, makes it possible, on the basis of experimentally recorded sedimentation curves, to identify quantitatively the values of the essential physical parameters of the coupled processes of erythrocyte aggregation and sedimentation. The analytical solution of Smoluchowski equation is used to evaluate the sedimentation and aggregation rate constants. The problem of determining the erythrocyte aggregation rate (EAR) is transformed to a minimization task in which only the experimental results for ESR are needed. Experimentally ESR is measured accurately enough by using an equipment set up just for the purpose. This method of identification could be used as a diagnostic test in hematological laboratories.     

Effects of a homogeneous magnetic field on erythrocyte sedimentation and aggregation

Effects of a homogeneous static magnetic field on erythrocyte sedimentation rate (ESR) have been assessed by using the standard Westergren method. A magnetic field of 6.3 T in the vertical direction only slightly enhanced ESR in saline solution, which was consistent with an effect on cell orientation. On the other hand, the magnetic field greatly enhanced ESR in plasma. It took a long time (about 20 min) for an ESR change to occur in plasma in response to the magnetic field. The effects in plasma were too large to originate only from cell orientation and were clearly distinct from a magnetic field-induced Boycott effect under an inhomogeneous magnetic field. A morphological examination and the nonlinear time course of the sedimentation in plasma indicated that the magnetic field increased cell aggregation and thereby enhanced ESR in plasma. Bioelectromagnetics 18:215–222, 1997. © 1997 Wiley-Liss, Inc.     

Effects of contrast media on erythrocyte aggregation during sedimentation

To evaluate the effects of contrast media (CMs) on erythrocyte aggregation, we measured the erythrocyte sedimentation with Westergren method at 25 degrees C. CMs were diatrizoate (Urografin 76%) for ionic CM and iopamidol (Iopamiron 370) for nonionic CM. Swine red blood cells (RBCs) were suspended in autologous plasma containing diatrizoate (URO), iopamidol (IOP), and saline (SAL) at 6.7% w/w, as well as in plasma alone (PLA), at 40% of the hematocrit. Sigmoid sedimentation curves were fitted to the Puccini et al. (1977) equation, and the average number of RBCs per aggregate m was calculated by Stokes' law against the time t. According to the Murata-Secomb (1988) theory we estimated the collision rate K between two aggregates from dm/dt in the stationary phase during sedimentation. Corresponding to the maximal ESR, the dm/dt (in cells/s) was 0.52 in PLA, 0.09 in SAL, 0.06 in URO and 0.03 in IOP, so that K also decreased in proportion to dm/dt from 145 fL/s in PLA to 8 fL/s in IOP. Both the ionic and nonionic CMs tend to inhibit the RBC aggregation more than that in SAL; the latter iopamidol appears to be inhibitory more than the former diatrizoate in autologous plasma.     

Influence of fibrinogen and haematocrit on erythrocyte sedimentation kinetics

This study investigates the influence of haematocrit, fibrinogen concentration and fibrinogen availability (amount of fibrinogen per red blood cell) on erythrocyte sedimentation. The Westergren technique was applied to blood samples from 36 subjects and to their blood manipulated to haematocrits of 10, 20, 30 and 40%. Readings were taken every 10 minutes for 300 minutes. Previous studies indicate that erythrocyte sedimentation occurs in three phases. In this study, we show that haematocrit has little influence on either the rate of fall of particles in the first phase (m1) or the duration of the first phase. This is also true for fibrinogen availability and for fibrinogen concentration at low haematocrits. At high haematocrits m1 increases with fibrinogen concentration. The rate of fall of rouleaux during phase 2 (m2) and ESR60 both decrease exponentially with haematocrit and increase linearly with fibrinogen concentration. While m2 is more closely correlated to fibrinogen availability than to fibrinogen concentration or to haematocrit, this is not the case for ESR60. Thus haematocrit, fibrinogen concentration and fibrinogen availability are more important to the velocity of sedimentation in the second phase than to the sedimenting velocity during phase 1 or to the duration of phase 1.     

Osmolality dependence of erythrocyte sedimentation and aggregation in a strong magnetic field

In order to specify the major determinant of the magnetic enhancement of erythrocyte sedimentation observed previously, the dependence of erythrocyte sedimentation rate (ESR) on osmolality was measured under a strong magnetic field. Even at hypotonic osmolality, an increase in ESR due to aggregation was observed in plasma solution as compared with that without aggregation in saline solution. However, the magnetic field did not enhance ESR at hypotonic osmolality, when the cell shape was an isotropic sphere (spherocyte). Thus, we narrowed our search to a mechanism that would explain the enhanced ESR found specifically in anisotropic erythrocytes. It was concluded that the major determinant can only work for anisotropic erythrocytes and is a magnetic field-induced increase in an intermembrane adhesive area due to magnetic orientation of anisotropic erythrocytes.     

Mathematical model describing erythrocyte sedimentation rate. Implications for blood viscosity changes in traumatic shock and crush syndrome

Background  

The erythrocyte sedimentation rate (ESR) is a simple and inexpensive laboratory test, which is widespread in clinical practice, for assessing the inflammatory or acute response. This work addresses the theoretical and experimental investigation of sedimentation a single and multiple particles in homogeneous and heterogeneous (multiphase) medium, as it relates to their internal structure (aggregation of solid or deformed particles).     

肠淋巴液引流对失血性休克大鼠红细胞流变性的影响

目的:观察肠淋巴液引流对失血性休克大鼠红细胞流变性指标以及血液黏度的作用。方法:Wistar雄性大鼠均分为假休克组、休克组(复制失血性休克模型)、引流组(复制失血性休克模型,自低血压1 h引流休克肠淋巴液)。在低血压3 h或相应时间,经腹主动脉取血,检测红细胞参数、红细胞电泳、红细胞沉降率(ESR)以及血液黏度,计算红细胞聚集指数、红细胞变形指数。结果:与假休克组比较,休克组红细胞数量、红细胞比积(HCT)、血红蛋白(Hb)、平均红细胞血红蛋白浓度(MCHC)、红细胞电泳率与迁移率、红细胞变形指数、全血黏度、全血低切与高切相对黏度和还原黏度显著降低,休克组平均红细胞体积、红细胞电泳时间、ESR、血沉方程K值与校正K值、红细胞聚集性指数、血浆黏度显著升高;引流组MCHC、红细胞电泳率与迁移率、全血黏度、全血低切与高切还原黏度均显著降低,引流组红细胞体积分布宽度(RDW-SD)显著增加。同时,引流组HCT、RDW-SD、红细胞变形指数、全血黏度、全血低切与高切相对黏度显著高于休克组;ESR、血沉方程K值与校正K值、红细胞聚集性指数、血浆黏度显著低于休克组。结论:休克肠淋巴液引流可改善失血性休克大鼠红细胞流变行为,从而改善血液流变性。     

Study of erythrocyte sedimentation behavior by piezoelectric crystal impedance sensor

Based on the impedance characteristic of erythrocytes at high frequency, the response of piezoelectric crystal impedance (PCI) sensor in the erythrocyte suspension was derived and verified experimentally. A method of using PCI sensor to investigate erythrocyte aggregation-sedimentation phenomenon was proposed. From the frequency response of the PCI sensor, the erythrocyte aggregation time and sedimentation rate could be obtained during erythrocyte aggregation and sedimentation. With the present method, the effects of the erythrocyte deformability, the osmotic pressure and the coexisting macromolecules on the erythrocyte sedimentation rate were studied. The results show that the PCI sensor possesses some advantages, such as good sensitivity, simplicity of use and no thermal effect for the impedance study of erythrocyte aggregation and sedimentation.     

肠系膜淋巴管结扎对急性失血大鼠红细胞流变性的影响

目的:观察结扎肠系膜淋巴管(MLD)对急性失血大鼠红细胞流变性的影响。方法:20只Wistar雄性大鼠随机均分为失血组与结扎组。所有大鼠经右侧颈总动脉匀速放血(失血量为全血量的1/4),结扎组失血后结扎MLD,失血组仅在MLD下穿线。记录24h存活情况。24h后,将存活大鼠经左侧颈总动脉迅速放血,测定实验前后的红细胞沉降率(ESR)、红细胞电泳、红细胞压积(Hct),计算红细胞聚集与变形指数。结果:急性失血后24h,结扎组大鼠存活情况(9只)略好于失血组(6只)。急性失血后24h,与实验前相比,失血组与结扎组的ESR、血沉方程K值、校正K值、红细胞电泳时间均显著升高或延长,红细胞变形性降低,失血组的红细胞聚集指数显著升高、红细胞电泳长度与迁移率均显著降低;结扎组的ESR、血沉方程K值、校正K值、红细胞聚集指数、电泳时间较失血组显著降低,红细胞电泳长度与迁移率、变形性较失血组显著升高。结论:急性失血导致大鼠红细胞聚集性升高、红细胞电泳能力及变形性降低,结扎MLD可改善急性失血导致的红细胞流变性异常。     

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.     

Graded alterations of RBC aggregation influence in vivo blood flow resistance

Although the effects of red blood cell (RBC) aggregation on low-shear rate blood viscosity are well known, the effects on in vivo flow resistance are still not fully resolved. The present study was designed to explore the in vivo effects of RBC aggregation on flow resistance using a novel technique to enhance aggregation: cells are covalently coated with a block copolymer (Pluronic F-98) and then suspended in unaltered plasma. RBC aggregation was increased in graded steps by varying the Pluronic concentration during cell coating and was verified by microscopy and erythrocyte sedimentation rate (ESR), which increased by 200% at the highest Pluronic level. RBC suspensions were perfused through an isolated in situ guinea pig hindlimb preparation while the arterial perfusion pressure was held constant at 100 mmHg via a pressure servo-controlled pump. No significant effects of enhanced RBC aggregation were observed when studies were conducted in preparations with intact vascular control mechanisms. However, after inhibition of smooth muscle tone (using 10(-4) M papaverin), a significant change in flow resistance was observed in a RBC suspension with a 97% increase of ESR. Additional enhancements of RBC aggregation (i.e., 136 and 162% increases of ESR) decreased flow resistance almost to control values. This was followed by another significant increase in flow resistance during perfusion with RBC suspensions with a 200% increase of ESR. This triphasic effect of graded increases of RBC aggregation is most likely explained by an interplay of several hemodynamic mechanisms that are triggered by enhanced RBC aggregation.     

Screening laboratory tests for Crohn's disease.

The prevalence of abnormal values of initial screening laboratory tests was assessed for 24 children who eventually proved to have Crohn''s disease. The screening tests included in this analysis were fecal alpha 1-antitrypsin (FA) concentration, erythrocyte sedimentation rate (ESR), total leukocyte count, serum albumin level, hemoglobin concentration, and qualitative testing of stool for the presence of blood. Of the 24 patients, 21 had abnormal FA values, 17 had anemia, 19 had an increased ESR, 14 had hypoalbuminemia, rectal bleeding was found in 8, and none had leukocytosis. All 24 patients had at least one abnormal screening test value; the most frequently abnormal result was the FA concentration. Pediatric patients without elevated FA values, anemia, a high ESR, bloody stools, or hypoalbuminemia are unlikely to have active Crohn''s disease.     

Correlated expression of adhesive properties for both white and red blood cells during inflammation

The state of leukocyte and erythrocyte adhesiveness/aggregation was determined in the peripheral blood of 382 patients with infection/inflammation as well as in 72 controls by using a simple slide test and image analysis. A highly significant correlation (r = 0.4, n = 455, p < 0.001) was found between the state of leukocyte and erythrocyte adhesiveness/aggregation. The extent of both leukocyte and erythrocyte aggregation correlated with the concentration of fibrinogen. Significant aggregation of leukocytes with erythrocytes was noted as well. We conclude that both leukocyte and erythrocyte aggregation occur in the peripheral blood of patients with infection/inflammation. Such cell aggregation, which might have detrimental rheological consequences, can be detected by using our novel technique.     

Biological effects of low-level,very low-frequency (VLF) electric fields on the blood sedimentation rate

Experiments were performed to detect a possible effect on in vitro irradiated human blood samples. The erythrocyte sedimentation rate (ESR) and the bioimpedence of both treated with a low-level 1.59 kHz electrical field and untreated blood samples were measured. A statistically significant difference (P < 0.001) was found in the blood sedimentation rates between Controls and those exposed to VLF-field condition. The most striking result was that for a 20% of the blood samples analyzed under the influence of the VLF-field, the ESR tests were almost stopped by the latter, i.e. the blood sedimentation did not occur. Bioimpedance value of stopped blood samples were one order of magnitude lower than those of unirradiated samples.     

分枝杆菌L型感染与肺癌患者红细胞免疫功能改变的相关性

目的:研究分枝杆菌L型血行感染与肺癌患者红细胞免疫功能改变的相关性.方法:溶血离心培养法和滴片法检测血液中的分枝杆菌L型,常规方法测定红细胞沉降率(ESR)、红细胞C3b受体花环率(C3bRR)、免疫复合物花环率(ICRR)、血清红细胞C3b受体花环促进率(RFER)和抑制率(RFIR).结果:TBL( )与TBL(-)肺癌患者相比,C3bRR和ICRR两项指标均明显降低.TBL( )肺癌与TBL(-)肺癌患者相比,ESR增快更为显著.TBL(-)较TBL( )之RFER值的降低更为明显.RFIR差异未见有显著性.结论:分枝杆菌L型血行感染影响肺癌患者血沉和红细胞免疫功能改变.     

Correlation analysis between some blood properties and atmospheric environmental parameters

S.W. Tromp made investigations of a weather effect on erythrocyte sedimentation rates (ESR) of human blood by routine checks of the blood of donor groups in Leiden from 1955 to 1985. A higher ESR was found for the summer season and lower ESR for winter and low values occurred soon after a strong cooling spell. In this report, we have continued his work using data for the years 1971–1985 from Leiden (The Netherlands). An influence of the weather on ESR was also found, but this seems to be more complicated than Tromp supposed. Some new aspects are described and elaborated, e.g. ESR already increases before warming is noticed at the ground layer. This is possibly caused by changes in the upper atmosphere, a suggestion that requires further studies. For periods of low ESR, there was a greater number of occlusion fronts passing the Netherlands. The long-term fluctuations of ESR that were found were correlated with sun spot relative numbers only in a few periods. The results of our study justify further research for a variety of other locations around the world.     

Simultaneous measurement of blood coagulation and erythrocyte sedimentation by means of a rheological technique

With a damped-oscillation rheometer, changes in the rheological properties, i.e., logarithmic damping factor (LDF) and period, as obtained from a damped-oscillation curve, were monitored during the coagulation of blood. In our earlier studies, the time of onset of coagulation (Ti) of the blood sample was only determined from the change in LDF. When coagulation of the blood and sedimentation of erythrocytes occurred together, the Ti value could not be determined from the change in LDF. In this paper, a method for determining the Ti value from the change in the period of the damped-oscillation curve was investigated. It was found that the period increased and leveled off as blood coagulation progressed, and the Ti value was determined from the middle point between the minimum and maximum values of the period. In addition, it was suggested that the level of erythrocyte sedimentation could be estimated from the initial decrease in LDF. In blood obtained from diabetic patients, a good correlation between the initial decrease in the LDF and the concentration of fibrinogen was observed. Our study demonstrates that when erythrocyte sedimentation and blood coagulation occur simultaneously, this rheological technique makes it possible to measure the Ti value and erythrocyte sedimentation.     

A physical theory of erythrocyte sedimentation

A new physical theory of erythrocyte sedimentation is proposed. Various assumptions underlying Stokes' formula are first criticized. An explicit formula is proposed, taking into account some of the results of recent experimental investigations including the effect of upward flow of plasma and the time course of growth of aggregates. It is generally shown that the sedimentation curve without aggregation never becomes a sigmoid. Our formula is applicable to the increased ESR due to the aggregation of erythrocytes. The sedimentation velocity depends not only on the hematocrit and the ultimate size of the aggregates, but also on the retardation time of the growth of aggregates in conformity with the experimental result of Kernick et al.     

High Fibrinogen in Peripheral Blood Correlates with Poorer Hearing Recovery in Idiopathic Sudden Sensorineural Hearing Loss

Objectives

We used hearing tests and peripheral blood sample analyses to characterize the pathology of idiopathic sudden sensorineural hearing loss (ISSNHL) and to identify possible prognostic factors for predicting recovery of hearing loss.

Study Design

A retrospective, multicenter trial was conducted.

Methods

Two hundred three patients examined within 7 days after the onset of ISSNHL received prednisone with lipo-prostaglandin E1. Pure-tone auditory tests were performed before and after treatment with these drugs. Blood tests were performed on blood samples collected during the patients’ initial visit to our clinic.

Results

In all patients, elevated white blood cell (WBC) counts, fasting blood sugar levels, HgbA1c, and erythrocyte sedimentation rate (ESR) significantly correlated with high hearing threshold measurements obtained on the initial visit. High fibrinogen levels, WBC counts, ESR, and low concentrations of fibrinogen degradation products (FDP) were associated with lower hearing recovery rates. Additionally, different audiogram shapes correlated with different blood test factors, indicating that different pathologies were involved.

Conclusions

High fibrinogen levels measured within seven days after ISSNHL onset correlated with poorer hearing recovery. This may be a consequence of ischemia or infections in the inner ear. The high WBC counts also observed may therefore reflect an immune response to inner ear damage induced by ischemic changes or infections. Our data indicate that therapeutic strategies should be selected based on the timing of initial treatment relative to ISSNHL onset.