Measurement of Red Blood Cell Aggregation
Oguz Baskurt, Björn Neu, Herbert J. Meiselman in Red Blood Cell Aggregation, 2011
Red blood cell (RBC) aggregation is a property of cells suspended in aggregating media, and is affected by both suspending phase and cellular properties (see Chapter 2). It should be noted that the suspending phase (i.e., plasma) and RBC properties may be altered under the influence of physiological and pathological processes as discussed in Chapter 8. Prominent changes in RBC aggregation can be detected in various diseases, including inflammatory states, vascular pathologies, and tissue perfusion problems inducing damage to RBC. Such alterations are reflected by various aspects of RBC aggregation. More specifically, these include: (1) the extent of aggregation (i.e., number of RBC in each aggregate), (2) the time course of aggregation (i.e., the rate of rouleaux formation), and (3) the magnitude of forces holding RBC together in aggregates.
Effect of Red Blood Cell Aggregation on Tube Flow
Oguz Baskurt, Björn Neu, Herbert J. Meiselman in Red Blood Cell Aggregation, 2011
Understanding blood flow in the circulatory system has attracted scientific interest for several centuries, with perhaps the most notable early work being the 1628 publication of An Anatomical Study of the Motion of the Heart and of the Blood in Animals by William Harvey. However, due to technical difficulties in conducting appropriate experiments in the vasculature of living organisms, blood flow studies until early in the twentieth century were mostly based on observations in cylindrical tubes. Therefore, observations on blood flow in narrow tubes have provided the majority of basic information on blood flow dynamics, including the influence of red blood cell (RBC) properties. These early studies on blood flow in cylindrical tubes are briefly summarized in this chapter, with more detailed information available elsewhere (Goldsmith et al. 1989).
Comparative Aspects of Red Blood Cell Aggregation
Oguz Baskurt, Björn Neu, Herbert J. Meiselman in Red Blood Cell Aggregation, 2011
It is well known that the aggregation of red blood cells (RBC) as discussed in this book is a mammalian feature. Mammalian RBC do not contain a nucleus or other organelles, while all nonmammalian species, including avian, reptile, and fish, are characterized by nucleated RBC (see frog RBC in Figure 9.1e as an example). Primarily due to an extensive degree of evolution, RBC in mammalian species are usually biconcave discs (Figure 9.1) with only a few exceptions (e.g., camelids, Figure 9.1c). This special geometry of RBC is common for all sub and infraclasses of the Mammalian class, including placental mammals, marsupials, and monotremes (Baskurt et al. 2010) that represent the first diversification of Mammalia dating back ~200 million years (Grutzner et al. 2003). It has been suggested that this special geometry evolved to optimize blood flow in the circulatory system (Uzoigwe 2006).
A Study on Analysis of Labeling Efficiency Depending on Mixing Time in Asan Medical Center Red Blood Cell Labeling Method
Published in Spectroscopy Letters, 2014
Eun-Mi Jeong, Ho-Sung Kim, Kyung Dong, Woon-Kwan Chung, Kyu-Ji Joo, Young-Jae Kim
ABSTRACT The aim of this study was to overcome the shortcomings of technetium-99m red blood cell labeling, such as the requirement of additional time, and to maintain a stable labeling efficiency by reducing the mixing time for technetium-99m red blood cell labeling in the Asan Medical Center red blood cell labeling method developed by this hospital. Thirty patients, who underwent an examination using technetium-99m red blood cell labeling in the nuclear medicine department from April to September 2012, were selected randomly. Blood samples (5 mL per patient) were mixed with acid citrate dextrose, and 1-mL aliquots were taken to make four blood samples. The Asan Medical Center red blood cell labeling method was used for labeling. In this case, the mixing time was set to 5, 10, 15, and 20 min before calculating the efficiency of each labeling. The difference depending on the mixing time was compared. According to the technetium-99m red blood cell labeling efficiency depending on the mixing time in the Asan Medical Center red blood cell labeling method, the efficiency of each labeling was 92 ± 5%, 96 ± 5%, 97 ± 5%, and 98 ± 5% for 5, 10, 15, and 20 min, respectively. Overall, the labeling efficiency was relatively low when the mixing time was 5 min, whereas there was no significant difference in labeling efficiency when the mixing time was longer than 5 min. In conclusion, the Asan Medical Center red blood cell labeling method can provide an environment that is more conducive to the combination of red blood cell with technetium-99m pertechnetate than the previous modified labeling method because the Asan Medical Center red blood cell labeling method removes blood plasma in an additional centrifugation process.
Cholinesterase Activity in Pregnant Women and Newborns
Published in Journal of Toxicology: Clinical Toxicology, 1994
Ann De Peyster, Winnie O. Willis, Michael Liebhaber
Plasma and red blood cell cholinesterase activity in blood samples from 259 pregnant women and cord blood from some of their newborn were compared with samples from 25 nonpregnant female volunteers and with laboratory norms (Ellman method). Plasma cholinesterase was significantly lower (p < 0.05) and red blood cell cholinesterase higher (p < 0.05) in pregnant women than in nonpregnant controls in a repeated measures analysis. By the sixth post-partum week, both plasma and red blood cell cholinesterase were similar to nonpregnant control activity. Fetal cord red blood cell cholinesterase activity was also lower than in nonpregnant women, but plasma levels were not significantly different. When compared with standard laboratory normal ranges, most (98-100%) plasma cholinesterase values in pregnant women and newborn were within range, whereas the majority (59-87%, depending on trimester) of red blood cell levels were above range in pregnancy and below range in 53% of newborns. A low red blood cell cholinesterase in pregnant women is more consistent with a possible overexposure to anticholinesterases than a low plasma cholinesterase. Periods of altered sensitivity to specific cholinesterase inhibiting drugs and environmental agents are suggested by these findings.
Red Blood Cell Susceptibility to Hydrogen Peroxide (H
Published in Clinical and Experimental Dialysis and Apheresis, 1982
To assess susceptibility to oxidant induced membrane damage, the red blood cell H2O2 hemolysis test was performed in fifty-three chronic hemodialysis patients. Uremic red blood cells were not more susceptible to 2.5% H2O2 lysis pre or postdialysis than were control red blood cells. Oxidant induced red blood cell lysis is a function of the strength of the oxidant and not a testable intrinsic defect of the uremic red blood cell.