Clinical Hemorheology and Microcirculation - Volume 71, issue 4

Authors: Varlet-Marie, Emmanuelle | Vachoud, Laurent | Marion, Bénédicte | Roques, Céline | Fidani, Thibault | Mercier, Jacques | Brun, Jean-Frédéric

Article Type: Research Article

Abstract:  The ideal hematocrit is the hematocrit (Hct) value resulting in the highest value of Hct/viscosity (h /η ) ratio and can thus be predicted from viscometric measurements with the use of equations such as Quemada’s one which yield the determination of the bell-shaped curve of h /η as a function of Hct. In a series of recent papers we applied this approach to various populations, using viscometry at high shear rate (1000 s–1 ). However the shape of this curve has been reported to be dependent on the shear rate, resulting in a right-shift in this top value when Hct …increase. We present here in 11 young recreative athletes the evolution of the predicted top of the h /η curve and optimal theoretical Hct and the discrepancy between theoretical and optimal values over the range of shear rates 1 to 6000 s–1 . Results show that the predicted optimal value of both h /η and Hct increases when shear rate increases and that the discrepancy between predicted laquooptimalraquo and actual values decreases and becomes almost asymptotic at very high shear (500 s–1 ). It is minimal at 2720 s–1 . The correlation between predicted laquooptimalraquo and actual values of both parameters describes the same evolution. Therefore, it is better for assessing h /η and its agreement with theoretical values, and for determining the theoretical ideal hematocrit, to measure blood viscosity at shear rates equal or superior to 500 s–1 . Show more

Keywords: Blood viscosity, hematocrit, hematocrit/viscosity ratio, oxygen delivery index

DOI: 10.3233/CH-199001

Citation: Clinical Hemorheology and Microcirculation, vol. 71, no. 4, pp. 379-385, 2019

Authors: Brun, Jean-Frédéric | Varlet-Marie, Emmanuelle | Boulot, Pierre | Marion, Bénédicte | Roques, Céline | Mercier, Jacques | Raynaud de Mauverger, Eric

Article Type: Research Article

Abstract: Physiological modifications of blood rheology during pregnancy and their alterations in pregnant hypertensive women have been extensively studied in the 1980’s. Since vascular resistance is higher in hypertensive pregnant women whose newborns are small-for gestational-age (SGA), we investigated in a personal database if growth retardation of newborns is related to the oxygen delivery index (ratio hematocrit/blood viscosity) and to the difference between hematocrit (Hct) and the prediction of its optimal valued based on Quemada’s equation. A sample of 38 hypertensive pregnant women (age 29 yr±1) was compared with 64 controls matched for age and gestational age, studied at 35±1 weeks gestation, …extracted from a larger series of 162 pregnant women. On the whole the hypertensive group gave birth to smaller children (p  = 0.014). Plasma viscosity correlated with blood pressure (BP) only in hypertensive women (r  = 0.403 p  < 0.05). The bell-shaped curve of predicted optimal Hct of non hypertensive pregnant women was similar to that of non-pregnant women, but in hypertensive women it was shifted toward higher values (p  = 0.07), and the predicted optimal Hct (but not the actual one) was correlated with systolic blood pressure (SBP) (r  = 0.349 p  < 0.001) and diastolic blood pressure (DBP) (r  = 0.218 p  < 0.05). The predicted optimal Hct/viscosity (h /η ) ratio was higher in hypertensive women whose newborns exhibited a low birth weight (p  = 0.03), resulting in a higher discrepancy between actual and model-predicted «ideal» values of h /η ratio (p  = 0.03) and Hct (p  = 0.02) compared with the subgroup with no growth retardation. Therefore, in hypertensive women whose newborns exhibited a low birth weight, hemorheological parameters predicting oxygen supply are shifted to lower values than predicted by the model. Show more

Keywords: Blood fluidity, hemostasis, pregnancy, hypertensive disorders of pregnancy, obesity, preeclampsia, small for gestational age

DOI: 10.3233/CH-199002

Citation: Clinical Hemorheology and Microcirculation, vol. 71, no. 4, pp. 387-396, 2019

Authors: Varlet-Marie, Emmanuelle | Vachoud, Laurent | Marion, Bénédicte | Roques, Céline | Fidani, Thibault | Chevalier, Constance | Mercier, Jacques | Raynaud de Mauverger, Eric | Brun, Jean-Frédéric

Article Type: Research Article

Abstract:  We previously reported that whole body bioelectrical impedance analysis (BIA) measurements are correlated to some hemorheologic factors, suggesting a relationship between viscosity factors and electric properties of flowing blood not only in vitro but also in vivo . Recently we reported that with segmental BIA (analyzing the body considered as composed of 5 cylinders) predictive equations for various determinants of blood viscosity were closer than for the wole body. Another widely used BIA technique uses leg-to-leg impedance measurements so that two cylinders (the two legs) are analyzed. We investigated whether impedance measured with this technique (Tanita TBF-300) is also …a predictor of blood viscosity factors. From viscometric measurements performed on venous blood drawn in recreative athletes over the range of shear rates 1 to 6000 s–1 (RHEOMETRE Anton Paar CP 50-1), we found a correlation between leg-leg resistance at 50 kHz (Rx[50 kHz]) and blood viscosity at 1000 s–1 (η 1000 = 0.0051 Rx[50 kHz] + 1.3265; r  = 0.521 p  = 0.028 yielding a prediction of η 1000 (Bland Altman plot: bias 0.05 [RANGE – 0.24; 0.34]. Neither plasma viscosity nor the red cell rheology index «k» of Quemada’s model are correlated with Rx[50 kHz], but hematocrit (Hct) does (Hct (%) = 0.0217 Rx[50 kHz] + 33.783; r  = 0.480 p  = 0.044) yielding a prediction of Hct (Bland Altman plot: bias – 0.11, [range – 1.67; 1.45]. The discrepancy between actual and predicted Hct is also correlated with resistance at 50 kHz (r  = 0.575 p  = 0.031) as does the discrepancy between actual and predicted Hct/viscosity ratio (r  = –0.651 p  = 0.006). Therefore, as other previously studied methods, leg to leg BIA predicts viscosity, suggesting that blood rheology may influence the passage of an electric current in the legs. Show more

Keywords: Segmental bioelectrical impedance, hematocrit, Myrenne aggregometer, Red blood cell aggregation, electrical conductance, light transmission

DOI: 10.3233/CH-199003

Citation: Clinical Hemorheology and Microcirculation, vol. 71, no. 4, pp. 397-402, 2019

Authors: Kerschhagl, M. | Larcher, L. | Mattiassich, G. | Prantl, L.

Article Type: Research Article

Abstract: BACKGROUND: Degloving injuries of the fingers and especially the thumb are highly demanding problems in hand surgery and replantation often is not successful because of severe soft tissue contusion. Only few cases of successfull replantation for hand degloving injuries in thumbs are reported in literature. CASE PRESENTATION: We present the case of a young right hand dominant worker experiencing an occupational accident with a circumferential avulsion of his right thumbs‘ soft tissue at the level of the metacarpophalangeal (MCP) joint with complete skeletization of his thumb and a deep laceration of the nail bed as he got trapped …in a machine. Bony structures and tendons remained intact corresponding Urbaniak class III/Kay class IV injury. Immediate defect coverage by replantation was performed. Additionally, a deep palmar soft tissue defect to his middle finger pulp and a laceration with disruption of his eighth finger nerve on his ring finger was adressed by revision, debridement, direct coaptation of the nerve and occlusive dressing to the middle finger. The patient regained full function and excellent cosmesis without nail deformity but only protective sensibility. He is back to his former sports and occupation. CONCLUSIONS: Though sensitive outcome is poor we recommend primary attempt for defect coverage with replantation following degloving to achieve pliable skin coverage and good cosmesis. Especially in Urbaniak III cases with complete soft tissue degloving lacking fractures or tendon lacerations good functional outcome is possible but we recommend to consent the patient in advance for other reconstructive options and give them realistic exspectations in case of failure. Contrary to popular belief replantation of completely degloved fingers is more than saving nonfunctional parts as motivated patients are able to get back to previous sports and occupation after successful replantation. Show more

Keywords: Degloving, avulsion, thumb, replantation

DOI: 10.3233/CH-199004

Citation: Clinical Hemorheology and Microcirculation, vol. 71, no. 4, pp. 403-414, 2019

Authors: Deng, Zijun | Zou, Jie | Wang, Weiwei | Nie, Yan | Tung, Wing-Tai | Ma, Nan | Lendlein, Andreas

Article Type: Research Article

Abstract:  Lipid-containing adipocytes can dedifferentiate into fibroblast-like cells under appropriate culture conditions, which are known as dedifferentiated fat (DFAT) cells. However, the relative low dedifferentiation efficiency with the established protocols limit their widespread applications. In this study, we found that adipocyte dedifferentiation could be promoted via periodic exposure to cold (10°C) in vitro . The lipid droplets in mature adipocytes were reduced by culturing the cells in periodic cooling/heating cycles (10–37°C) for one week. The periodic temperature change led to the down-regulation of the adipogenic genes (FABP4, Leptin) and up-regulation of the mitochondrial uncoupling related genes (UCP1, PGC-1α , and PRDM16). …In addition, the enhanced expression of the cell proliferation marker Ki67 was observed in the dedifferentiated fibroblast-like cells after periodic exposure to cold, as compared to the cells cultured in 37°C. Our in vitro model provides a simple and effective approach to promote lipolysis and can be used to improve the dedifferentiation efficiency of adipocytes towards multipotent DFAT cells. Show more

Keywords: Adipocyte, dedifferentiation, cold, lipid

DOI: 10.3233/CH-199005

Citation: Clinical Hemorheology and Microcirculation, vol. 71, no. 4, pp. 415-424, 2019

Authors: Kuhnla, A. | Reinthaler, M. | Braune, S. | Maier, A. | Pindur, Gerhard | Lendlein, A. | Jung, F.

Article Type: Research Article

Abstract: Thrombotic disorders remain the leading cause of mortality and morbidity, despite the fact that anti-platelet therapies and vascular implants are successfully used today. As life expectancy is increasing in western societies, the specific knowledge about processes leading to thrombosis in elderly is essential for an adequate therapeutic management of platelet dysfunction and for tailoring blood contacting implants. This study addresses the limited available data on platelet function in apparently healthy subjects in relation to age, particularly in view of subjects of old age (80–98 years). Apparently healthy subjects between 20 and 98 years were included in this study. Platelet function …was assessed by light transmission aggregometry and comprised experiments on spontaneous as well as ristocetin-, ADP- and collagen-induced platelet aggregation. The data of this study revealed a non-linear increase in the maximum spontaneous platelet aggregation (from 3.3% ±3.3% to 10.9% ±5.9%). The maximum induced aggregation decreased with age for ristocetin (from 85.8% ±7.2% to 75.0% ±7.8%), ADP (from 88.5% ±4.6% to 64.8% ±7.3%) and collagen (from 89.5% ±3.0% to 64.0% ±4.0%) in a non-linear manner (linear regression analysis). These observations indicate that during aging, circulating platelets become increasingly activated but lose their full aggregatory potential, a phenomenon that was earlier termed “platelet exhaustion”. In this study we extended the limited existing data for spontaneous and induced platelet aggregation of apparently healthy donors above the age of 75 years. The presented data indicate that the extrapolation of data from a middle age group does not necessarily predict platelet function in apparently healthy subjects of old age. It emphasizes the need for respective studies to improve our understanding of thrombotic processes in elderly humans. Show more

DOI: 10.3233/CH-199006

Citation: Clinical Hemorheology and Microcirculation, vol. 71, no. 4, pp. 425-435, 2019

Authors: Dinarelli, Simone | Girasole, Marco | Misiti, Francesco

Article Type: Research Article

Abstract: BACKGROUND: Circulating red blood cells (RBCs) undergo aging, a fundamental physiological phenomenon that regulates their turnover. Objective: Understanding the role of Aβ in the cross talk between cell signalling pathways and modulation of the cell structural and biomechanical properties occurring in RBCs during aging. METHODS: The morphological pattern has been monitored using Atomic Force Microscopy (AFM) imaging and measuring the RBCs’ plasma membrane roughness employed as a morphological parameter capable to provide information on the structure and integrity of the membrane-skeleton. RESULTS: We show that treatment with Aβ accelerates the occurrence of morphological and biochemical aging …markers in human RBC and influences the cell metabolism. Biochemical data demonstrate that contemporaneously to morphological alterations, Aβ triggers: (i) metabolic alterations and (ii) a complex signaling pathway involving caspase 3, protein kinase C and nitric oxide derived metabolites. CONCLUSIONS: our study provides a comprehensive picture in which Aβ treatment of RBC induces changes in specific cell signalling events and/or metabolic pathways, in turns affecting the membrane–cytoskeleton interaction and the membrane integrity. Show more

Keywords: Amyloid beta peptide, RBC, nitric oxide synthase, PKC, caspase 3, atomic force microscopy, membrane roughness

DOI: 10.3233/CH-199007

Citation: Clinical Hemorheology and Microcirculation, vol. 71, no. 4, pp. 437-449, 2019

Authors: Kalender, G. | Lisy, M. | Stock, U.A. | Endisch, A. | Kornberger, A.

Article Type: Research Article

Abstract: Endovascular repair of aortic aneurysms (EVAR) has become an established treatment option currently applied in an increasing numbers of patients with aortic aneurysms. Advantages include reduced surgical trauma, procedural time, intensive care unit and hospital lengths of stay, blood loss as well as morbidity and mortality. The optimal imaging modalities in EVAR follow-up as well as the appropriate intervals between these follow-ups remain subject of controversial discussion. Objective of this study was the evaluation of the realistic radiation exposure and risk estimate postop EVAR treatment. Of the follow-ups required according to the surveillance schedule during the first year …post-EVAR, only 68.3% were actually implemented. Of those required from the second year onwards, an average of 70% was actually performed. During the observation period, each patient underwent a mean of 4.3 CTAs. The median ED calculated from all CTAs was 24. 5 mSv. The minimum and maximum cumulative EDs for the entire observation period were 55 mSv and 310 mSv, respectively. Show more

Keywords: EVAR, radiation exposure, CTA, aortic aneurysms

DOI: 10.3233/CH-170344

Citation: Clinical Hemorheology and Microcirculation, vol. 71, no. 4, pp. 451-461, 2019

Authors: Unver, Fatma | Kilic-Toprak, Emine | Kilic-Erkek, Ozgen | Korkmaz, Halil | Yasin, Ozdemir | Oymak, Burak | Oskay, Alten | Bor-Kucukatay, Melek

Article Type: Research Article

Abstract: BACKGROUND: The Nordic hamstring exercise (NHE) has been proven to be an effective preventive technique for hamstring injuries. Hemorheological parameters (erythrocyte deformability and aggregation) play a critical role in exercise influencing oxygenation. Although previous studies presented hemorheological alterations induced by different types of exercise, changes in red blood cell (RBC) deformability and aggregation following NHE remain unknown. Present study was designed to explore possible alterations in hemorheological and oxidative parameters after an acute bout of NHE. METHODS: 10 healthy, male, active students (mean age 19.9±0.23, BMI: 21.56±0.54) participated to the study. They performed a single session of seven-repetitions …of NHE followed by a familiarisation period. Blood samples were obtained before and immediately after the exercise from the antecubital vein. Hemorheological parameters were measured by an ektacytometer. RESULTS: NHE did not change deformability, hematocrit and oxidative stress but, increased RBC aggregation index (AI, p  = 0.011) and decreased RBC aggregation half time (t½, p  = 0.009). CONCLUSIONS: Our results suggest that, increased RBC aggregation following an acute bout of NHE may result in increased plasma skimming and thus ease the flow of blood. Show more

Keywords: Nordic hamstring exercise, RBC deformability, erythrocyte aggregation, oxidative stress

DOI: 10.3233/CH-180402

Citation: Clinical Hemorheology and Microcirculation, vol. 71, no. 4, pp. 463-473, 2019

Authors: Blaslov, Kristina | Kruljac, Ivan | Mirošević, Gorana | Gaćina, Petar | Kolonić, Slobodanka Ostojić | Vrkljan, Milan

Article Type: Research Article

Abstract: BACKGROUND Although it is considered that the pathogenesis of diabetic retinopathy (DR) in type 2 diabetes mellitus (T2DM) is primarily due to chronic hyperglycemia resulting in vascular changes and retinal ischemia, the red blood cells (RBCs) disorders might also represent an important pathophysiological risk factor. OBJECTIVE To evaluate whether the RBC properties contribute to DR development and progression in T2DM. METHODS This prospective observational study comprised 247 persons with T2DM free of DR or with non proliferative DR without any signs of anaemia. The patients were reacessed after 60-months. RESULTS The mean age of …our study population was 56 years, 54.9% males with diabetes duration of 11,18±1,28 years. During the follow up, 16 (5.84%) participants developed non proliferative DR and 9 (3.64%) progressed to PDR while the mean corpuscular volume (MCV) and red cell distribution width (RDW) MCV rose. Both MCV and RDW correlated positively with HbA1c (r  = 0,468, p  = 0.003 and r  = 0.521, p  < 0.001), while Cox regression analysis revealed that besides age, diabetes duration, HbA1c, hypertension and dyslipidemia presence, MCV and RDW are also associated with the risk of DR development and progression (HR 1.057 and 1.237, p  < 0.001). CONCLUSIONS We clearly demonstrated that RBC’s characteristics might represent a risk factor for DR development and progression. Show more

Keywords: Diabetic retinopathy, red blood cells, mean corpuscular volume, red cell volume distribution width

DOI: 10.3233/CH-180422

Citation: Clinical Hemorheology and Microcirculation, vol. 71, no. 4, pp. 475-481, 2019