Clinical Hemorheology and Microcirculation - Volume 60, issue 4

Authors: Smith, Michael M. | Lucas, Alexander R. | Hamlin, Robert L. | Devor, Steven T.

Article Type: Research Article

Abstract: This study examined the relationship between hematocrit, blood viscosity, plasma viscosity, erythrocyte deformability, and fibrinogen concentration during maximal oxygen uptake in aerobically trained (AT) and resistance trained (RT) athletes. Maximal oxygen uptake was assessed using a Bruce graded exercise treadmill test to exhaustion, and blood samples were collected at rest and immediately following exercise using a venous catheter. Viscometric analyses were performed using a cone and plate viscometer at varying shear rates. Hematocrit was measured as the fraction of erythrocytes suspended in plasma following centrifugation. Erythrocyte rigidity was estimated using the Dintenfass index of red blood cell rigidity. Following maximal …treadmill exercise, an increase of blood viscosity at varying shear rates (22.50, 45.00, 90.00, and 225.00 s- 1 ; P  <  0.05) was observed in RT athletes only. Plasma viscosity @ 225.00 s- 1 (1.88 ± 0.09 vs. 1.78 ± 0.03 mPa.s; P  <  0.05), erythrocyte rigidity (0.52 ± 0.08 vs. 0.40 ± 0.09; P  <  0.05), and plasma fibrinogen (434 ± 7 vs. 295 ± 25 mg/dL; P  <  0.01) were all significantly greater in RT than AT athletes following maximal exercise. In summary, AT, but not RT, is associated with a hemorheological profile that promotes both oxygen transport and delivery. The results indicate that hematocrit alone should not be the focus of training and ergogenic supplementation to increase aerobic performance. Show more

Keywords: Fibrinogen, erythrocyte, exercise, hematocrit, viscosity

DOI: 10.3233/CH-131708

Citation: Clinical Hemorheology and Microcirculation, vol. 60, no. 4, pp. 347-362, 2015

Authors: Marchewka, Anna | Filar-Mierzwa, Katarzyna | Dąbrowski, Zbigniew | Teległó, Aneta

Article Type: Research Article

Abstract: The aim of this study was to analyze the effects of motor rehabilitation, in the form of rhythmic exercise to music, on the rheological characteristics of blood in older women. The study included 30 women (65–80 years of age), and the control group was comprised of 10 women of corresponding age. Women from the experimental group were subjected to a five-month rehabilitation program, in the form of rhythmic exercise performed to music (three 30-minute sessions per week); women from the control group were not involved in any regular physical activity. Blood samples from all the women were examined for hematological, …rheological, and biochemical parameters prior to the study and five months thereafter. The rehabilitation program was reflected by a significant improvement of erythrocyte count and hematocrit. Furthermore, an improvement of erythrocyte deformability was observed by lower shear stress levels, while no significant changes were noted by the higher shear stress values. The rehabilitation resulted in a marked decrease of the aggregation amplitude while no significant changes were observed in aggregation index and total aggregation half-time. Additionally, the training regimen was reflected by a significant increase in the plasma viscosity, while no significant changes in fibrinogen levels were noted. Show more

Keywords: Elderly, exercise to music, hemorheology, rehabilitation, rhythmic exercise

DOI: 10.3233/CH-131793

Citation: Clinical Hemorheology and Microcirculation, vol. 60, no. 4, pp. 363-373, 2015

Authors: Mazzulla, S. | Schella, A. | Gabriele, D. | Baldino, N. | Sesti, S. | Perrotta, E. | Costabile, A. | de Cindio, B.

Article Type: Research Article

Abstract: The main aim of this study was the investigation of the rheological properties of Red Blood Cells (RBCs) obtained from subjects admitted to blood donors, associated with the lipid profile of High-Density Lipoprotein Cholesterol (HDL-C), Low-Density Lipoprotein Cholesterol (LDL-C), Triglyceride (TG) and Total Cholesterol (TOT-C). The deformability index of RBCs was determined by using a Dynamic Stress Rheometer (DSR-500) under oxidative injury induced by 2.2′ -azo-bis (2-amidinopropane) dihydrochloride (AAPH). An increased rigidity of RBCs in subjects with borderline level of hyperlipidemia was found, compared with the control group. In order to explain the reason for the reduced deformability, a borderline …group was studied for the evaluation of anionic permeability on membrane, haemolysis and morphological changes induced by AAPH, as well as ThioBarbituric Acid Reactive Substances (TBARs) generation. Haemolysis by AAPH indicated a decrease of globular resistance in the borderline group, furthermore, the elevated values of TBARs suggested lipid peroxidative damage to the RBCs membrane associated with morphological changes and anion permeability alterations. Our study shows the correlation between biochemical and morphological parameters of RBCs and their rheological behavior during oxidative injury. Rheological studies might be useful as a clinical and diagnostic monitoring technique and provide support for further research. Show more

Keywords: RBC rheology, anionic permeability, haemolisys, TBARs, rheology

DOI: 10.3233/CH-141841

Citation: Clinical Hemorheology and Microcirculation, vol. 60, no. 4, pp. 375-388, 2015

Authors: George, R.B. | DesRoches, J. | Abdo, I. | Lehmann, C.

Article Type: Research Article

Abstract: BACKGROUND: Pregnancy places significant demands on the cardiovascular system leading to measurable changes in the macrocirculation and potentially the microcirculation. During labour, both uterine contractions and labour pain can further impact cardiovascular status. The objective of this observational study was to compare sublingual microcirculation in labouring parturients before and after epidural analgesia. METHODS: Healthy pregnant, labouring women requesting epidural analgesia were approached to participate. Participants with cardiovascular disease, diabetes, obesity, smoking or caffeine intake were excluded. The sidestream dark field device was applied to the sublingual mucosa obtaining images of at least 20 seconds in …5 visual fields before and after epidural analgesia. Video clips were analyzed randomly and blindly. The primary outcome was mean microvascular flow index (MFI). RESULTS: Twelve participants completed this study. The results demonstrate no statistically significant difference in the MFI during labour pain (2.9±0.1) compared to after epidural analgesia (3.0±0.04, p  = 0.31). Furthermore, there were no statistically significant differences in any secondary outcomes. CONCLUSION: Our findings indicate that epidural analgesia may not impact sublingual microcirculation in labouring women. This agrees with literature supporting epidural analgesia as a safe, appropriate method of pain relief during labour with limited impact on peripheral macro or microcirculation. Show more

Keywords: Microcirculation, epidural, sidestream dark field imaging

DOI: 10.3233/CH-141851

Citation: Clinical Hemorheology and Microcirculation, vol. 60, no. 4, pp. 389-395, 2015

Authors: Teixeira, Pedro | Napoleão, Patrícia | Saldanha, Carlota

Article Type: Research Article

Abstract: Glutathione is an abundant molecule inside erythrocyte, originating S-nitrosoglutathione (GSNO) by reacting with nitric oxide (NO). GSNO has been regarded as a store and transporter of NO, with significant interest as a potential therapeutic agent, acting as an NO donor. NO metabolism inside the erythrocyte generates several derivatives, which can be altered by external and internal stimuli such as acetylcholine (ACh), a natural substrate of acetylcholinesterase (AChE). In spite of the knowledge gained in the last decades concerning NO efflux in erythrocytes little is known regarding erythrocyte GSNO efflux, which has also a significant role in microcirculation. Hence, the …objective of this research was to evaluate the efflux of GSNO, concomitant with the efflux of NO, after stimulation with AChE effectors. To achieve these goals, the in vitro effect of AChE modulators – ACh and timolol – in erythrocyte NO and GSNO were studied. Timolol is an erythrocyte AChE inhibitor. Venous blood samples were collected from 18 healthy Caucasian men. For each blood sample, erythrocyte suspensions were obtained and incubated in the absence (controls) and presence of ACh and timolol maleate (10 μM final concentration of each modulator). Both timolol and ACh induced significant GSNO efflux in the erythrocyte when compared to the control; however the efflux was lower in the presence of timolol compared to ACh. Although erythrocyte NO efflux in presence of timolol is similar to the control, the efflux decreased when compared to the ACh treatment. The presence of timolol induces significant decrease of intra-erythrocyte GSNO levels, relative to control and ACh treatment. In conclusion, when erythrocytes were stimulated with ACh or timolol, GSNO efflux occurred associated with NO efflux. These new results bring new insight into the metabolism of erythrocyte NO and new possible therapeutic applications for GSNO. Show more

Keywords: Erythrocyte, nitric oxide, S-nitrosoglutathione, acetylcholine, timolol maleate

DOI: 10.3233/CH-141855

Citation: Clinical Hemorheology and Microcirculation, vol. 60, no. 4, pp. 397-404, 2015

Authors: Maslov, Mikhail Y. | Chernysheva, Galina A. | Smol’jakova, Vera I. | Aliev, Oleg I. | Kolosova, Natalia G. | Plotnikov, Mark B.

Article Type: Research Article

Abstract: Rheohaemapheresis aims to normalize major rheological parameters and is used to treat patients with dry age-related macular degeneration (AMD). While effective, this approach is invasive and requires specially trained personnel. Therefore, the search for novel effective compounds with hemorheological properties that can be taken orally to treat AMD is justified. The use of a robust rodent model of AMD with high blood viscosity is crucial to test the efficacy of potential hemorheological drugs to treat this disease. The objective of this study was to investigate whether OXYS rats, generally used as an animal model of AMD, have hyperviscosity syndrome. The …results of this study show that blood viscosity in OXYS rats at low (3–10 s −1 ) and high (45–300 s −1 ) shear rates were 14–20% and 7–10% higher than in Wistar rats, while hematocrit and plasma viscosity were not different. Red blood cells (RBCs) in OXYS rats were more prone to aggregation as shown by 39% shorter half-time than in Wistar rats. RBCs were also more rigid in OXYS than in Wistar rats as shown by 21–33% lower index of elongation at the shear stress of 1–7 Pa. These data indicate that OXYS rats have hyperviscosity syndrome as the result of abnormal RBC deformability and aggregation. We propose to use OXYS rats as an animal model for preclinical studies to test compounds with hemorheological properties aimed to treat AMD. Show more

Keywords: OXYS rats, hyperviscosity syndrome, whole blood viscosity, plasma viscosity, RBC aggregation, RBC deformability

DOI: 10.3233/CH-141860

Citation: Clinical Hemorheology and Microcirculation, vol. 60, no. 4, pp. 405-411, 2015

Authors: Charlot, Keyne | Waltz, Xavier | Hedreville, Mona | Sinnapah, Stéphane | Lemonne, Nathalie | Etienne-Julan, Maryse | Soter, Valérie | Hue, Olivier | Hardy-Dessources, Marie-Dominique | Connes, Philippe

Article Type: Research Article

Abstract: Oxygen uptake efficiency slope (OUES) and excess post-exercise oxygen consumption (EPOC) are markers of physical fitness in the general population but have never been characterized in sickle cell anemia (SCA) where hematological and hemorheological properties are severely altered. Eight SCA patients and eleven healthy subjects (CONT) performed a submaximal incremental exercise conducted until the first ventilatory threshold (VT1). OUES was calculated from the data collected during the incremental period and EPOC parameters (amplitude [A] and time constant [τ ]) were calculated from the data measured during exercise recovery. We found that OUES (p  = 0.007) and A (p  = 0.010) were lower, …and τ (p  = 0.035) was higher, in SCA patients compared to CONT subjects. OUES and τ were significantly correlated with hematocrit, red blood cell (RBC) deformability and RBC aggregates strength. Our findings suggest that both the abilities to use oxygen during exercise and to recover after a physical activity are impaired in SCA patients. This poor physical fitness seems to depend on the degree of anemia and RBC rheological alterations. Show more

Keywords: Physical activity, sickle cell disease, hemorheology, physical fitness, exercise recovery

DOI: 10.3233/CH-141891

Citation: Clinical Hemorheology and Microcirculation, vol. 60, no. 4, pp. 413-421, 2015

Authors: Finzgar, Miha | Melik, Ziva | Cankar, Ksenija

Article Type: Research Article

Abstract: BACKGROUND: The inefficient healing of chronic wounds is a result of poor blood perfusion at the wound and surrounding tissues. Artificially applied carbon dioxide (CO2 ) has the potential to improve the perfusion and oxygenation of tissues, hence is useful for the healing of chronic wounds. OBJECTIVE: The aim of the present study was to determine the effect of a transcutaneous application of physiological vasodilator gaseous CO2 on cutaneous blood flow. METHODS: Laser Doppler (LD) flux in cutaneous microcirculation, skin temperature, electrocardiogram and arterial blood pressure were measured simultaneously in a …group of 33 healthy men, aged 21–28 years, during rest and a 35-minute CO2 therapy. One lower limb of each subject represented the studied extremity, being exposed to gaseous CO2 . The contralateral limb was the control, being exposed to air. Each limb was sealed in a plastic bag. RESULTS: During CO2 therapy the LD flux in the studied extremity increased from 5.8 PU ± 3.9 PU to 30.3 PU ± 16.7 PU (mean ± standard deviation; paired t -test, p  <  0.001), while that in the control extremity did not change significantly. CONCLUSIONS: Our results confirm a local vasodilatory effect of applied CO2 therapy. This finding indicates its potential clinical use. Show more

Keywords: Physiological measurements, laser Doppler fluxmetry, CO2 therapy, dry CO2 bath

DOI: 10.3233/CH-141898

Citation: Clinical Hemorheology and Microcirculation, vol. 60, no. 4, pp. 423-435, 2015

Authors: Reinhart, Sophie A. | Schulzki, Thomas | Reinhart, Walter H.

Article Type: Research Article

Abstract: The storage of red blood cells (RBCs) leads to storage lesions, which have a negative impact on the clinical outcome after transfusion. A hallmark of storage lesions is echinocytosis. Albumin may reverse this shape transformation, which was the topic of this study. Echinocytosis was generated by incubation of blood for 48 h at room temperature or in RBC units stored 48 days at 5°C. Human serum albumin was diluted in phosphate-buffered saline. RBCs were fixed in 1% glutaraldehyde and examined by light and scanning electron microscopy. The degree of echinocytosis was quantified by calculating the morphological index. Incubation and storage of …RBCs led to an echinocytic shape transformation, which was reversible upon incubation in albumin solutions. This process was time-, concentration- and hematocrit-dependent. Treating RBC units at the end of their shelf-life by adding 20% albumin or washing them in 0.2% albumin reversed all degrees of echinocytosis towards discocytosis. In conclusion, albumin has the capacity to reverse echinocytosis generated by RBC storage. This observation may improve the quality of RBC units stored for longer periods of time. Show more

Keywords: Albumin, blood storage, echinocyte, erythrocyte, transfusion

DOI: 10.3233/CH-141899

Citation: Clinical Hemorheology and Microcirculation, vol. 60, no. 4, pp. 437-449, 2015

Authors: Badiei, N. | Sowedan, A.M. | Curtis, D.J. | Brown, M.R. | Lawrence, M.J. | Campbell, A.I. | Sabra, A. | Evans, P.A. | Weisel, J.W. | Chernysh, I.N. | Nagaswami, C. | Williams, P.R. | Hawkins, K.

Article Type: Research Article

Abstract: Incipient clot formation in whole blood and fibrin gels was studied by the rheometric techniques of controlled stress parallel superposition (CSPS) and small amplitude oscillatory shear (SAOS). The effects of unidirectional shear stress on incipient clot microstructure, formation kinetics and elasticity are reported in terms of the fractal dimension (d f ) of the fibrin network, the gel network formation time (T GP ) and the shear elastic modulus, respectively. The results of this first haemorheological application of CSPS reveal the marked sensitivity of incipient clot microstructure to physiologically relevant levels of shear stress, these being an order …of magnitude lower than have previously been studied by SAOS. CSPS tests revealed that exposure of forming clots to increasing levels of shear stress produces a corresponding elevation in d f , consistent with the formation of tighter, more compact clot microstructures under unidirectional flow. A corresponding increase in shear elasticity was recorded. The scaling relationship established between shear elasticity and d f for fibrin clots and whole blood confirms the fibrin network as the dominant microstructural component of the incipient clot in terms of its response to imposed stress. Supplementary studies of fibrin clot formation by rheometry and microscopy revealed the substantial additional network mass required to increase d f and provide evidence to support the hypothesis that microstructural changes in blood clotted under unidirectional shear may be attributed to flow enhanced thrombin generation and activation. CSPS also identified a threshold value of unidirectional shear stress above which no incipient clot formation could be detected. CSPS was shown to be a valuable haemorheological tool for the study of the effects of physiological and pathological levels of shear on clot properties. Show more

Keywords: Gel point, clotting time, fractal dimension, shear stress, controlled stress parallel superposition

DOI: 10.3233/CH-151924

Citation: Clinical Hemorheology and Microcirculation, vol. 60, no. 4, pp. 451-464, 2015

Article Type: Other

Citation: Clinical Hemorheology and Microcirculation, vol. 60, no. 4, pp. 465-471, 2015