Clinical Hemorheology and Microcirculation - Volume 28, issue 3

Authors: Häfner, H.‐M. | Thomma, S.R. | Eichner, M. | Steins, A. | Jünger, M.

Article Type: Research Article

Abstract: Emla® cream is frequently used in surgical dermatology and in anesthesiology, for instance, during vascular surgery procedures. Because local anesthetics can have a vasoactive effect in addition to producing analgesia, we decided to document the effect of 5% Emla® cream on cutaneous circulation in a prospective, placebo‐controlled study. Skin circulation was monitored continuously under standardized conditions using video capillaroscopy, laser Doppler flowmetry and skin temperature. Recordings were made at the nailfold of the fourth finger (DIV) of the left hand of 12 volunteers with healthy veins over an observation period of 60 minutes under either Emla® occlusive …dressing or an occlusive dressing with placebo. Mean capillary red blood cell velocity changed only minimally under the Emla® occlusive dressing, while placebo occlusive dressing led to a reduction of mean capillary red blood cell velocity from 0.21 mm/s to 0.12 mm/s (p<0.01). There was no statistically significant change of arterial capillary diameter under Emla® or placebo occlusive dressing. Skin temperature dropped after 60 minutes of Emla® cream occlusive dressing from an initial 26.7 to 24.0°C (−10.1%; p<0.02). The same duration of placebo caused skin temperature to drop from 27.6 to 23.0°C (−16.7%; p<0.001). Laser Doppler flux (543 nm) rose 13% with Emla® (p=0.9) and dropped 41.9% under placebo occlusive dressing (p<0.03). Emla® cream upregulated nutritive perfusion. No clinically relevant vasoconstrictive effects are expected from an application period of 60 minutes. Show more

Keywords: Local anesthesia, capillaroscopy, laser Doppler flux, lidocaine, prilocaine

Citation: Clinical Hemorheology and Microcirculation, vol. 28, no. 3, pp. 121-128, 2003

Authors: Varlet‐Marie, E. | Gaudard, A. | Mercier, J. | Bressolle, F. | Brun, J.‐F.

Article Type: Research Article

Abstract: Bioelectrical impedancemetry (BIA) has received a widespread interest as a non‐invasive approach to body fluid volumes. Since similar techniques have been studied to assess in vitro rheological properties of blood, we investigated the relationships between whole body impedance and blood viscosity parameters in order to determine possible predictive equations. 30 sportsmen (24.6±1.01 years; 73.96±1.62 kg; 177.73±1.33 cm) were enrolled into the study. Body composition was assessed with a multifrequency bioelectrical impedancemeter (Dietosystem Human IM Scan) using low intensity at the following frequencies: 1, 5, 10, 50 and 100 kHz. Viscometric measurements were done at 1000 s−1 with a falling …ball viscometer (MT 90 Medicatest). Hematocrit (Hct) was measured with microcentrifuge. A standardized exercise test was performed on a cycloergometer during 25 minutes. Physical working capacity (W170 ) was calculated and VO2 max  was evaluated with Astrand nomograms. Two hemorheological parameters were independently correlated with impedance (Z) measurements: whole blood viscosity (WBV) at 100 kHz (r=0.518; p=0.01) and Hct at 1 kHz (r=−0.485; p=0.01). Plasma viscosity was correlated multilinearly with water/fat free mass and Z at 10 kHz (r=0.441; p=0.02). In addition both WBV and Z at 100 kHz exhibited correlations with aerobic working capacity (VO2 max  ) with r=−0.482 and r=−0.475 (p≤0.05), respectively. A stepwise regression analysis selects Z at 100 kHz instead of WBV as a predictor of VO2 max  . These findings confirm our previous reports about relationships between whole body conductance for high frequency and aerobic working capacity and suggest a new approach for non‐invasive evaluation of blood rheology with BIA. Show more

Keywords: Exercise, impedance, body fluids, blood viscosity, plasma viscosity, hemorheology, aerobic working capacity

Citation: Clinical Hemorheology and Microcirculation, vol. 28, no. 3, pp. 129-137, 2003

Authors: Varlet‐Marie, E. | Gaudard, A. | Monnier, J.‐F. | Micallef, J.‐P. | Mercier, J. | Bressolle, F. | Brun, J.‐F.

Article Type: Research Article

Abstract: Effects of exercise on erythrocyte aggregation were investigated in 19 elite athletes. High shear rate viscometry (1000 s−1 ) evidenced an increase in blood viscosity explained by an increase in hematocrit (+8% p<0.01) and plasma viscosity (+7% p<0.01). Erythrocyte rigidity index and erythrocyte aggregability measured using the Myrenne erythroaggregometer did not change. However, using the laser backscattering technique (SEFAM erythroaggregometer), we observed significant changes in aggregability and desaggregability after 25 min of exercise. The initial aggregation time (TA) decreased by 33% (p<0.01), while the final aggregation time decreased by 13.6% (p<0.01). TA was correlated with areobic working capacity (r=0.73; p=0.005), …which was negatively correlated with blood viscosity at rest (r=−0.57; p=0.043). A significant relationship was observed between TA and the initial fibrinogen levels (r=0.71; p<0.01). The plasma volume contraction during exercise was found to be statistically explained by the water loss proportional to the total work load. Thus, laser backscattering demonstrates an increase in aggregability and a decrease in disaggregability of red cells during exercise, proportional to baseline fibrinogen values. Show more

Keywords: Exercise, erythrocyte deformability, erythrocyte aggregability, fibrinogen, rheology

Citation: Clinical Hemorheology and Microcirculation, vol. 28, no. 3, pp. 139-149, 2003

Authors: Varlet‐Marie, E. | Gaudard, A. | Mercier, J. | Bressolle, F. | Brun, J.‐F.

Article Type: Research Article

Abstract: The feeling of having “heavy legs” (FHL) is commonly reported in the overtraining syndrome (OTS), i.e., the condition wherein an athlete is training excessively, yet performance deteriorates. Since FHL is also a sign of chronic venous insufficiency where it can be corrected by rheo‐active drugs, and given the fact that OTS is also a hemorheologic disease associated with mild hemoconcentration, we investigated whether the FHL is associated with a hemorheologic profile. 37 athletes training 13.05±0.97 hr/week completed the French questionnaire of Overtraining (mean score: 11.66±1.96) and underwent a medical check‐up including hemorheological measurements. 14 subjects quote the item: “I have …the FHL”. Although well matched with the 23 others for age and body composition, FHL subjects had higher plasma viscosity (1.44±0.05 vs 1.32±0.02 mPa.s; p<0.05) and a higher red cell aggregation as measured with laser backscattering (Affibio indices: final aggregation time “TF”: 36.77±1.88 vs 44.26±2.37; p<0.05; aggregation index at 10 s “S10 ”: 26.31±1.14 vs 21.92±1.19; p<0.05). The OTS score was correlated positively with plasma viscosity (r=0.549; p=0.008), whole blood viscosity (r=0.4458; p=0.03), and the following aggregability parameters: “S10 ” (r=0.4818; p=0.0232) and the aggregation index at 60 s “S60 ” (r=0.4601; p=0.0312). The OTS score was also correlated negatively with the aggregability parameters “TF” (r=−0.4432; p=0.0389) and the initial aggregation time “TA” (exponential relationship r=−0.458; p=0.03). These findings suggest that the feeling of heavy legs in overtrained athletes is related to OTS‐related hemorheologic disturbances, namely mild plasma hyperviscosity and mild erythrocyte hyperaggregability. Show more

Keywords: Athletes, overtraining, heavy legs, blood viscosity, plasma viscosity, aggregability

Citation: Clinical Hemorheology and Microcirculation, vol. 28, no. 3, pp. 151-159, 2003

Authors: Gaudard, A. | Varlet‐Marie, E. | Bressolle, F. | Mercier, J. | Brun, J.‐F.

Article Type: Research Article

Abstract: Negative correlations between blood viscosity parameters and fitness have been reported, but their physiological meaning remains incompletely understood. Since rheo‐active treatments are used in athletes doping, we aimed at clarifying the relationships between hematocrit (Hct), viscosity and performance by comparing aerobic capacity, overtraining questionnaire, and hemorheological parameters. Subjects and methods: 29 sportsmen (24.71±1.05 yr; 74.90±1.44 kg; 178.5±1.05 cm) underwent a standardised exercise test. Physical working capacity (W170 ), maximal power output (Wmax  ) and maximal oxygen consumption (VO2 max  ) were calculated. Viscometric measurements were done with a MT 90 Medicatest viscosimeter. Hct was measured with microcentrifuge. All subjects …answered the overtraining questionnaire proposed by the French Society for Sports Medicine. Results: The best correlate of maximal power output (Wmax  ) was whole blood viscosity (r=−0.383, p<0.001). The stepwise regression analysis only selected Hct as W170 determinant (r=−0.66, p<0.001). Similarly the best determinant of VO2 max  , expressed as a percentage of theoretical values, was Hct (r=−0.462, p=0.01). Hct/viscosity ratio (Hct/η), a proposed index of Hct's positive influence on O2 transfer to tissues, was positively correlated to Wmax  expressed as a percentage of theoretical values (r=0.487, p=0.02). The overtraining score was correlated to plasma viscosity (r=0.450, p=0.016). Conclusion: The best hemorheogical correlate of fitness is a low hematocrit and the best hemorheological correlate of overtraining is increased plasma viscosity. Show more

Keywords: Exercise, rheology, viscosity parameters, physical working capacity, fitness, unfitness, overtraining, doping

Citation: Clinical Hemorheology and Microcirculation, vol. 28, no. 3, pp. 161-173, 2003

Authors: Rickert, Dorothee | Moses, M.A. | Lendlein, A. | Kelch, S. | Franke, R.‐P.

Article Type: Research Article

Abstract: The uncomplicated outcome of surgical interventions after biomedical application of biomaterials depends on successful wound healing. Wound healing is a highly complex process compossed of a number of overlapping phases, including inflammation, epithelialization, angiogenesis and matrix deposition. Inadequate angiogenesis limits the transport between the microvasculature and implanted biomaterials. The regulation of angiogenesis is based on numerous growth factors, proteolytic enzymes, extracellular matrix components, cell adhesion molecules, and vasoactive factors. Capillary endothelial cells were grown for different time periods (day 1, 3, 6, 9 and 12) on the surface of a recently developed biodegradable polymeric biomaterial. As control the cells were …seeded on the gelatine coated polystyrene surface of commercially available cell cultures dishes. Endothelial cells became adherent and showed confluent cells layers during increasing time period on both surfaces. The total cell number of cells grown on the gelatine coated polystyrene surface was higher in comparison to the polymer surface. The chorioallantois membrane (CAM) assay was used as a sensitive assay to investigate the influence of angiogenesis in vivo. After 48 hours of exposure of the CAM to polymer samples no avascular zones, free of capillaries and/or thrombosis or hemorrhage were detectable. Considering the biofunctionality of our recently developed polymer in these experiments different surface modifications of the polymer are the topic of current investigation to support the biomaterial–microvasculature interactions in vivo. Show more

Citation: Clinical Hemorheology and Microcirculation, vol. 28, no. 3, pp. 175-181, 2003

Authors: Binzen, E. | Rickert, D. | Kelch, S. | Fuhrmann, R.

Article Type: Research Article

Abstract: Biomaterial research is expected to forward new materials to be used as, e.g., implant materials or as scaffolds for tissue engineering. It is central for such a scaffold material to create the track on which those cells can inhabitate the scaffold needed to rebuild functional tissue substitutes. The tissue engineering concept expects a gradual gain in functionality of the newly created tissues while the scaffold materials are degraded and subsequently eliminated. Not only for the elimination of the degradation products the angiogenesis of new blood vessels is thought to play an important role. In the present study, a new biomaterial, …a non‐porous polymeric AB‐network based on oligo (ε‐hydroxycaproat) and oligobutylacrylat, was implanted in animals. Male NMRI mice were implanted subcutaneously for one week. Immediately after the explantation, the probes were examined histologically. Already one week after implantation, there was a strong tissue‐integration of the polymer. Importantly, blood vessels occurred at the polymer surface. There were also clusters of cells around the vessels, which were phenotypically similar to fat cells. The mechanism of the early integration of the polymer is not clear. The relationship between the new periimplant vessels and the integration of the polymer has to be studied. Show more

Citation: Clinical Hemorheology and Microcirculation, vol. 28, no. 3, pp. 183-188, 2003