bluuebunny/crossref_metadata_2025 huggingface dataset:
Rheological blood behavior is not only influenced by cardiovascular risk factors but also by aging itself. Research into 927 healthy Spanish Mediterranean subjects
Authors: Vayá Amparo , Alis Rafael , Romagnoli Marco , Pérez Rafael , Bautista Daniel , Alonso Ricardo , Laiz Begoña
Published: December 2019

It is not well-established whether the alterations that the hemorheological profile undergoes with aging are an effect of concomitant cardiovascular risk factors or are due to age itself. To clarify this issue, we investigated the effect of age on blood rheology in a population of 927 healthy subjects from eastern Spain aged between 16–85 years, divided into four age groups (<30, 30–44, 45–50, ≥60 years) with and without cardiovascular risk factors. We determined blood viscosity, corrected blood viscosity (BVc), plasma viscosity (PV), erythrocyte aggregation (EA), erythrocyte deformability (EEI60) and fibrinogen, along with glucose and plasma lipids. We found that corrected blood viscosity (p = 0.007), plasma viscosity, erythrocyte aggregation, fibrinogen, glucose, and plasma lipids increased with age (p < 0.001). When subjects with cardiovascular risk factors were excluded, the effect of age on blood rheology persisted for all the cited parameters (p < 0.028). EEI60 increased with age (p = 0.033), and it was attributable to a concomitant increase in mean corpuscular volume (p < 0.001). In the Pearson's correlations, age was related to all the parameters analyzed (P < 0.019). The logistic regression analysis revealed that PV ≥1.30 mPa·s, BVc ≥4.90 mPa·s and EA1 ≥8.3 were associated with age ≥60 years (*p = 0.049, *p = 0.013, *p = 0.045, respectively). These results indicate that, although the presence of cardiovascular risk factors influences rheological properties, aging itself is associated with deterioration of rheological blood behavior, mostly related to inflammatory and lipidic changes.
Laser Doppler flux measurement for the assessment of cutaneous microcirculation – critical remarks
Authors: Jung F. , Leithäuser B. , Landgraf H. , Jünger M. , Franzeck U. , Pries A. , Sternitzky R. , Franke R.P. , Forconi S. , Ehrly A.M.
Published: December 2019

Back scattered Laser Doppler (LD) signals are composed of two different individual signals. The number of the moving particles and the speed of the particles in the measured tissue volume determine the frequency shift and the band width of the Doppler signal. The dependence of the Laser Doppler flux on the number of scattering particles is highly nonlinear: at very low hematocrit and high speed the axial migration of the cells to the centre of the blood vessels is very strong, so that in these cases – because of the parabolic flow profile - the Doppler flux measurement overestimates the mean real blood flow (up to two- or three-fold). The opposite is the case when the hematocrit is very high, then the blood flow might be underestimated (due to the increased amounts of blood cells near the vessel wall). In addition, a very change in number of moving particles - as can occur during the postprandial phase or during therapy - can change the signal also at a constant cell number. Also, it must be mentioned that the LD signal possibly is not only reflected by moving blood cells in the different skin layers but also by blood cells flowing in tissues below the skin (particularly below atrophied skin areas of older patients) so that in such cases the LD Flux signal reflects not exclusively the skin blood flow. Therefore, LD flux at rest may still be within the normal range even in advanced states of disease, since the scattered light is sampled from a tissue volume which may contain also non-nutritive shunt vessels. This critical analysis of the LD signals of course shall not lead to an overall rejection of the application of laser Doppler systems. Actual progress only can, however, be obtained under the exact consideration of anatomical conditions, technical restrictions and when generalizations are avoided.
Prospective clinical trial on dosage optimizing of tranexamic acid in non-emergency cardiac surgery procedures
Authors: Waldow T. , Szlapka M. , Haferkorn M. , Bürger L. , Plötze K. , Matschke K.
Published: December 2019

After withdrawal of aprotinin in 2008 only tranexamic acid (TxA, Cyclocapron, Pfitzer, Germany) remains available as antihyperfibrinolytic agent in Europe. Dosage (from 1 g to 20 g) and application strategy (single shot i.v., infusion i.v., topical) reflect an indiscriminate use of TXA in cardiac surgery. We use data analysis of three registries to evaluate safety issues and sufficiency of different TxA dosages in our center. METHODS: Registry 1: Single shot ultra-low dose TxA (1 g in priming volume). Registry 2: Single shot medium dose TxA (5 g in priming volume). Registry 3: Single shot medium dose TxA (3 g in priming volume) and continuous, weight-adapted administration during cross clamping. Independence of surgeon's preference was achieved by changing dosage every surgery day regardless of operation schedule. RESULTS: Data analysis was carried out on 1182 consecutive, elective patients (1 g TxA n = 415; 3 g + x g TA n = 367; mean TxA dose 4.4 g ± 1.0 g; 5 g TxA n = 400). Patient characteristics were well matched in all three registries (mean age: 69 ± 9.5y, BMI 28.2 ± 4.7, Creatinin 107.5 ± 52.8 μM), as were performed surgical procedures (excluding organ transplantation). Postoperative data showed no significant differences for blood loss and major adverse events (1 g vs. 3 + g vs. 5 g: blood loss: 894 ± 1479 vs. 903 ± 1282 vs. 1004 ± 1604 ml; stroke: 1.5 vs. 1.6 vs. 1.5%; myocardial infarction 2.7 vs. 3.3 vs. 1.3%; 30d mortality 3.9 vs. 4.2 vs. 4.8%, respectively). Secondary endpoints (de novo dialysis, transfusion requirement, ICU and total treatment time) showed no significant differences between registries. CONCLUSION: Use of 1 g TxA is safe and sufficient for elective patients with on pump cardiac surgery and thus has been established as strategy of choice in our center.
Influence of iodine-containing radiographic contrast media on the phenotype of erythrocytes from different laboratory animal species
Authors: Hiebl B. , Hopperdietzel C. , Hünigen H. , Dietze K. , Klein S. , Schreier B. , Jung F.
Published: December 2019

It is well known that clinically relevant concentrations of iodine-containing radiographic contrast media (CM) induce morphological changes in human erythrocytes. However, there are only few reports about CM effects on erythrocytes of animals (e.g. mice, rats, rabbits, and pigs). Thus, two conventional iodine-containing CM (iodixanol, Visipaque™ 320; iomeprol, Iomeprol™ 350) were tested for their effects on the morphology of erythrocytes from these. After venous blood sampling and blood centrifugation, the autologous plasma was supplemented with 40 vol% CM. Then, a defined number of erythrocytes was incubated in this CM-supplemented plasma for 5 min at body temperature (37°C). Subsequently, 10 μL of the cell suspension were transferred to a purified glass slide and the number of discocytes, echinocytes, and acanthocytes was counted within a total number of 100 erythrocytes (40 fold primary magnification, transmitted light mode). Shape changes of the erythrocytes from all animal species strongly depended on the type of CM and compared to the effects which have already been described for human erythrocytes. Incubation in both CM resulted in morphological changes of the erythrocytes. Incubation in a iodixanol/plasma mixture induced the lowest echinocyte or acanthocyte formation. Porcine erythrocytes showed a much more distinct shape change than those of other animal species and humans. These results suggest erythrocytes from mice, rats, and rabbits are a suitable model system for human erythrocytes when CM effects on the cellular shape of erythrocytes have to be tested. The distinct deformation of the pig erythrocytes could be due to differences in the pig erythrocyte membrane or the physical and chemical constitution of pig erythrocytes.
Effect of polystyrene and polyether imide cell culture inserts with different roughness on chondrocyte metabolic activity and gene expression profiles of aggrecan and collagen
Authors: König Josephine , Kohl Benjamin , Kratz Karl , Jung Friedrich , Lendlein Andreas , Ertel Wolfgang , Schulze-Tanzil Gundula
Published: December 2019

In vitro cultured autologous chondrocytes can be used for implantation to support cartilage repair. For this purpose, a very small number of autologous cells harvested from a biopsy have to be expanded in monolayer culture. Commercially available polymer surfaces lead to chondrocyte dedifferentiation. Hence, the demanding need for optimized polymers and surface topologies supporting chondrocytes' differentiated phenotypes in vitro arises. In this study we explored the effect of tailored cell culture plate inserts prepared from polystyrene (PS) and polyether imide (PEI) exhibiting three different roughness levels (R0, RI, RII) on chondrocyte morphology, metabolism and gene expression profile. As a control, commercially available tissue culture plastic (TCP) dishes were included. Primary porcine articular chondrocytes were seeded on tailored PS and PEI inserts with three different roughness levels. The metabolic activity of the chondrocytes was determined after 24 hours using alamar blue assay. Chondrocyte gene expression profiles (aggrecan, type I and type II collagen) were monitored after 48 hours using Real Time Detection (RTD)-PCR. Chondrocytes cultured on PS and PEI surfaces formed cell clusters after 24 and 48 hours, which was not observed on TCP. The metabolic activity of chondrocytes cultured on PS was lower than of chondrocytes cultured on PEI, but also lower than on TCP. Gene expression analyses revealed an elevated expression of cartilage-specific aggrecan and an impaired expression of both collagen types by chondrocytes on PS and PEI compared with TCP. In summary, PEI is a biocompatible biomaterial suitable for chondrocyte culturing, which can be further chemically functionalized for generating specific surface interactions or covalent binding of biomolecules.
Erythrocyte osmotic fragility increases with serum advanced glycated end products in cigarette smokers
Authors: Li Rulin , Chen Xuyang
Published: December 2019

BACKGROUND: This study examines the relationship between circulating advanced glycated end products (AGEs) level and erythrocyte osmotic fragility in smokers. METHODS: Forty-eight smokers (aged 45 ± 5 years) and fifty healthy nonsmokers (aged 42 ± 6 years) were selected in this study. All subjects were analysed according to serum AGEs, osmotic fragility (H50, the NaCL concentration producing 50% hemolysis), malondialdehyde (MDA) and advanced oxidation protein products (AOPP). RESULTS: The data show that the serum AGEs, H50, MDA and AOPP levels were significantly higher for smokers than that of nonsmokers (p < 0.01). The serum AGEs correlated with H50 in smokers (r = 0.7703, p < 0.01). MDA levels correlated with H50 in smokers (r = 0.7584, p < 0.01). CONCLUSIONS: This study demonstrated that serum AGEs and MDA levels positively correlated with osmotic fragility in smokers.
Signature biomarkers in Diabetes Mellitus and associated Cardiovascular diseases
Authors: Karmakar Tanusri , Mallick Sanjaya K. , Chakraborty Arpita , Maiti Animesh , Chowdhury Subhankar , Bhattacharyya Maitree
Published: December 2019

Platelet signatures indicating differential dysfunction, hyperactivation, aggregation or adhesion are capable of expressing their characters during the journey of a disease process, and can be utilized as cost effective biomarkers with immense clinical value. Type 2 diabetes mellitus (T2DM) is a major lifestyle disease of contemporary world with progression to diabetes associated cardiovascular diseases (DM-CVD). We identified a few potential biomarkers in platelets of T2DM to analyze the thrombotic risk in diabetes subjects by utilizing flow cytometric quantification with different flurochrome conjugated monoclonal antibodies. Our study describes interesting correlations (p < 0.0001) for different clinical parameters of concurrent threat for vessel occlusion and the status of indices like reactive oxygen species, von Willebrand factor and mitochondrial membrane potential using western blotting and fluorescence techniques. Our study involved 32 T2DM, and 31 T2DM - CVD subjects compared to 29 healthy controls without any history of T2DM or CVD. An altered expression of platelet surface markers P-selectin (CD62p) and GpIIb/IIIa (CD 41/61, PAC1) along with changes in the platelet size due to agonist induced activation contributed to the enhanced thrombotic potential in the patients. This work elucidates the prospect of platelet biomarkers as diagnostic tool to predict cardiovascular risk in DM subjects.
Effect of erythrocyte aggregation at pathological levels on NO/O2 transport in small arterioles
Authors: Cho Seungkwan , Namgung Bumseok , Kim Han Sung , Leo Hwa Liang , Kim Sangho
Published: December 2019

This study examined the effects of red blood cell (RBC) aggregation at pathological levels on NO/O2 transport in small arterioles. Transient gas diffusion simulations were performed with in vivo cell-free layer (CFL) widths data obtained from arteriolar flows in the rat cremaster muscle. The CFL data were measured at physiological and pathological levels of aggregation under reduced flow conditions (pseudoshear rate = 31.4 ± 10.5 s−1). Our results showed that the mean peak NO concentration significantly decreased with increasing the aggregation level from non-aggregating to normal-aggregating (P < 0.05) and to hyper-aggregating (P < 0.01) conditions. In contrast, the partial O2 pressure (PO2) in pathological aggregating conditions significantly increased from those under non-aggregating (P < 0.001) and normal-aggregating (P < 0.05) conditions. Although the NO scavenging by RBCs could be impaired with a thicker CFL at higher levels of aggregation, the overall decrease in NO production due to reduction of wall shear stress with the thicker CFL dominantly limited the NO availability in tissue. On the other hand, the O2 availability in tissue increased due to the relatively high core hematocrit in the blood lumen with the thicker CFL.
Pressure monitoring during lipofilling procedures
Authors: Klein S.M. , Prantl L. , Geis S. , Eisenmann-Klein M. , Dolderer J. , Felthaus O. , Loibl M. , Heine N.
Published: December 2019

BACKGROUND: Grafting of autologous lipoaspirate for various clinical applications has become a common procedure in clinical practice. With an estimated mortality rate of 10–15 percent, fat embolism is among the most severe complications to be expected after lipofilling therapies. OBJECTIVE: The aim of this study was to determine the level of interstitial pressure after the injection of defined volumes of lipoaspirate into the subcutaneous tissue of female breasts. It was hypothesized, that interstitial pressure levels exceed the physiologic capillary pressure during lipofilling procedures and hence increase the potential risk for fat embolism. Further it was investigated if external tissue expansion has the potential to significantly reduce interstitial tissue pressure. METHODS: Interstitial pressure was monitored in 36 female patients, that underwent autologous fat injections into the breast. Measurements were conducted with a sensor needle connected to a pressure transducer (LogiCal Pressure Monitoring Kit, Smiths medical int. Ltd., UK). Patients were divided into 4 subcohorts differing in their pre-treatment regimen or local tissue conditions. Pre-treatment consisted of tissue expansion, achieved with the Brava™ (Brava LLC Miami, Fla., USA) vacuum-chamber. RESULTS: The increase in interstitial pressure after injection volumes of 100 ml (p = 0.006), 200 ml (p = 0.000) and between 100 ml and 200 ml (p = 0.004) respectively, were significant in non-mastectomized patients without pre-treatment. Patients pre-treated with Brava™ did not show such statistically significant differences in interstitial pressures before and after the injection of 100 ml and 200 ml of lipoaspirate (p = 0.178). The difference in interstitial pressure in mastectomized patients between 0 ml and 100 ml (p = 0.003), as well as 0 ml and 200 ml (p = 0.028) was significant. The difference in pressures between pre-treated patients and patients without pre-treatment did not differ significantly in the mastectomized patient cohort. CONCLUSION: During lipofilling procedures interstitial pressures are reached that exceed pressure limits defined as hazardous for fat embolism. To date it is unknown what pressure levels need to be considered critical for complications in soft tissue interventions. Further the results indicate higher interstitial pressures for patients that had undergone mastectomy, whereas pre-treatment with external tissue expansion seemed to diminish pressure values.
Color-coded perfusion analysis of CEUS for pre-interventional diagnosis of microvascularisation in cases of vascular malformations
Authors: Teusch V.I. , Wohlgemuth W.A. , Piehler A.P. , Jung E.M.
Published: December 2019

AIM: Aim of our pilot study was the application of a contrast-enhanced color-coded ultrasound perfusion analysis in patients with vascular malformations to quantify microcirculatory alterations. MATERIAL AND METHODS: 28 patients (16 female, 12 male, mean age 24.9 years) with high flow (n = 6) or slow-flow (n = 22) malformations were analyzed before intervention. An experienced examiner performed a color-coded Doppler sonography (CCDS) and a Power Doppler as well as a contrast-enhanced ultrasound after intravenous bolus injection of 1 – 2.4 ml of a second-generation ultrasound contrast medium (SonoVue®, Bracco, Milan). The contrast-enhanced examination was documented as a cine sequence over 60 s. The quantitative analysis based on color-coded contrast-enhanced ultrasound (CEUS) images included percentage peak enhancement (%peak), time to peak (TTP), area under the curve (AUC), and mean transit time (MTT). RESULTS: No side effects occurred after intravenous contrast injection. The mean %peak in arteriovenous malformations was almost twice as high as in slow-flow-malformations. The area under the curve was 4 times higher in arteriovenous malformations compared to the mean value of other malformations. The mean transit time was 1.4 times higher in high-flow-malformations compared to slow-flow-malformations. There was no difference regarding the time to peak between the different malformation types. The comparison between all vascular malformation and surrounding tissue showed statistically significant differences for all analyzed data (%peak, TTP, AUC, MTT; p < 0.01). High-flow and slow-flow vascular malformations had statistically significant differences in %peak (p < 0.01), AUC analysis (p < 0.01), and MTT (p < 0.05). CONCLUSION: Color-coded perfusion analysis of CEUS seems to be a promising technique for the dynamic assessment of microvasculature in vascular malformations.
Effect of radiographic contrast media (Iodixanol, Iopromide) on hemolysis
Authors: Gerk U. , Krüger A. , Franke R.P. , Jung F.
Published: December 2019

Radiographic contrast media can lead to drastic changes of the morphology of erythrocytes. The change of the erythrocyte morphology is associated with a decreased deformability possibly resulting from distinctions in the loss of constituents of the membrane cytoskeleton. However, it is unclear whether there is an intravascular hemolysis as a consequence of the disintegration of the erythrocyte membrane. The results of this study showed, that free haemoglobin increased from 16.8 ± 10.0 mg/dl to 21.6 ± 12.6 mg/dl after Iopromide application (p = 0.240), while it slightly decreased from 20.5 ± 10.3 mg/dl to 19.5 ± 12.2 mg/dl after Iodixanol application (p = 0.547). The slight decrease of free haemoglobin after application of Iodixanol differed significantly compared to the increase of free haemoglobin after Iopromide application (p < 0.05). This different response is thought to give evidence to the assumption that the erythrocyte membrane integrity was compromised leading to the release of free haemoglobin as an indicator of hemolysis as well.
Endothelial dysfunction after stenting and scaffolding of coronary arteries
Authors: Gori Tommaso , Münzel Thomas
Published: December 2019

Coronary artery stenting is associated with endothelial dysfunction, probably caused by the mechanical injury as well as by the tissue reactions triggered by the metal, the polymer and the drug eluted by the stent. The clinical relevance, and the implications, of this dysfunction are still unclear. We revise the iterature on this topic and provide the first evidence regarding endothelial dysfunction after implantation of bioresorbable scaffolds.
Thrombotic events in systemic lupus erythematosus. Its association with acquired and inherited thrombophilic defects
Authors: Vayá Amparo , Santaolaria Marisa , Micó Luisa , Calvo Javier , Oropesa Roberto , Villa Piedad , Todoli Jose , Simó María , Corella Dolores , Ricart Jose M.
Published: December 2019

Systemic lupus erythematosus (SLE) is characterised by increased venous and arterial thrombotic risk. Although antiphospholipid antibodies (APAs) have been shown to be related with thrombotic tendency in these patients, in more than 40% of them, thrombosis occurs without the presence of such antibodies. We analysed the association of venous and arterial thrombotic events with acquired (anticardiolipin antibodies (ACAs) and lupus anticoagulant (LA)) and inherited (antithrombin (AT), protein C (PC), protein S (PS) deficiencies, factor V Leiden and the prothrombin G20210A mutation), thrombophilic risk factors in 86 SLE patients and 89 healthy controls. Patients showed a higher significant percentage of ACAs titres IgG>41 GPL u/ml and LA than controls (P=0.009; P<0.001, respectively), although no differences in AT, PC, PS deficiencies, factor V Leiden and prothrombin G20210A mutation was observed (P>0.05). When patients with and without thrombosis were compared, those with thrombosis showed a statistically higher percentage of ACAs IgG>41 GPL u/ml and LA (P=0.048; P=0.001, respectively), OR 4.33; 95% CI 1.01–18.50 and OR 11.57; 95% CI 3.28–40.75, respectively. When venous and arterial thrombotic events were considered separately, the presence of LA constituted a risk factor for arterial thrombosis (P=0.010), OR 11.33; 95% CI 1.86–68.89, as well as for venous thrombosis (P=0.005), OR 10.15; 95% CI 2.12–48.64, while ACAs IgG>41 GPL u/ml on their own, were not associated with arterial or venous thrombosis (P=0.142, P=0.233, respectively). In addition inherited thrombophilic risk factors AT, PC, PS deficiencies, factor V Leiden and PT G20210A mutation do not seem to increase thrombotic risk in SLE patients.
Hemorheological changes caused by intermittent Pringle (Baron) maneuver in beagle canine model
Authors: Furka A. , Nemeth N. , Gulyas A. , Brath E. , Peto K. , Takacs I.E. , Furka I. , Sapy P. , Miko I.
Published: December 2019

In liver resection operations the Pringle (Baron) maneuver can be used for temporary ischemia by clamping the hepatoduodenal ligament intermittently. In this beagle canine model we investigated whether hemorheological parameters may alter in systemic, portal and hepatic venous blood and in arterial samples during–after Pringle maneuvers. In Pringle Group unilateral femoral artery and external jugular vein were cannulated. From median laparotomy the hepatoduodenal ligament was exposed. The portal venous system was catheterized via a mesenteric vein and through the inferior caval vein a catheter was led to the hepatic veins. After stabilization, a 15-minute Pringle maneuver was carried out three times with 5-minute interpolated reperfusion periods. In Control Group Pringle maneuvers were not made. Before and after Pringle maneuvers parallel blood samples were taken from the cannulated vessels for determining hematological parameters and erythrocyte aggregation. Following Pringle maneuvers erythrocyte deformability, blood and plasma viscosity were also tested. The results showed that besides systemic hemorheological effects of the intermittent Pringle maneuver local leukocyte count, hematocrit and erythrocyte aggregation index altered mainly in portal venous blood, depending on the repeating number of the maneuvers. Thus, investigations of hemorheological parameters might be useful to determine the optimal duration of the Pringle maneuver.
In vitro effect of aluminium upon erythrocyte membrane properties
Authors: Hernández G. , Bollini A. , Huarte M. , Bazzoni G. , Piehl L. , Chiarotto M. , Rubín de Celis E. , Rasia M.
Published: December 2019

The link between aluminium (Al(III)) and a range of disorders in organisms (plants and animals including human beings) has been stated in diverse studies. As regards as human beings in particular, there are numerous studies on this metal's toxicity in relation to pathological processes. Only few references to the metal's effect upon cell rheological properties can be found. In this study, we present evidence for alterations in the rheological properties of cells as consequence of the Al(III)'s interaction with human red blood cell membrane. Al(III) could damage membrane functions of the red blood cell by favouring lipid peroxidation reactions due to the presence of Fe(II) as an initiator. The metal's effect on lipid bilayer, and probably on the cytoskeleton as well, would constitute the cause for the impaired erythrocyte rheology.
Postoperative assessment of free skin flap viability by transcutaneous pO2 measurement using dynamic phosphorescence imaging
Authors: Geis S. , Schreml S. , Lamby P. , Obed A. , Jung E.M. , Nerlich M. , Babilas P. , Szeimies R.-M. , Prantl L.
Published: December 2019

Background: Free flap transplantation is used more and more frequently in order to cover extensive wound defects. The basic prerequisite for successful flap salvage after flap failure is a short time interval from failure until revision. For this reason many different flap monitoring systems have been tested over the last years. But none of them has made the way into clinical routine.

Objective: The aim of this clinical study was to study whether luminescence lifetime imaging (LLI) is an adequate method to assess flap viability during the postoperative period. In previous experiments LLI was proven to be a precise and non-invasive monitoring system for transcutaneous oxygen measurement.

Methods: ptcO2 of 9 patients was detected during a postoperative period of 72 hours. In all cases the transplantation was performed by the same experienced surgeon. During the first 4 hours almost constant ptcO2 values were detected (53±0.7 mmHg). During the following time intervals ptcO2 values decreased and reached a more or less constant level after approximately 12 hours. The mean ptcO2 decreased from 53±0.7 mmHg to 39±1.0 mmHg. In one case an immediate decrease of ptcO2 below 10 mmHg was observed and a subsequently intervention was necessary to improve flap perfusion.

Conclusion: In this clinical trial, perfusion dynamics after free flap transplantation as well as the detection of vascular complications were demonstrated using LLI. Based on these data, LLI seems to be a sensitive and adequate monitoring system for the evaluation of free flap viability.
The use of antithrombotic agents in microvascular surgery
Authors: Stephan B. , Schenk J.F. , Nemeh A. , Pindur G.
Published: December 2019

Despite increasing advances in microvascular free tissue transfer, flap failures, most commonly resulting from thrombosis at the anastomotic vascular site, remain a significant concern. Although several experimental and clinical studies have been carried out, no consensus has been reached so far on the efficacy, dosage and timing of anticoagulant agents available for the prevention and treatment of thrombosis in microvascular surgery. Inhibition of fibrin formation and platelet function or the use of thrombolytic agents is a common approach in the antithrombotic management. However, some agents exhibit serious side effects and all of them carry the risk of bleedings. The current literature on the use of antithrombotic agents, targeting at clinical trials in microvascular surgery, is therefore reviewed, to provide an informative basis for recommendations for an appropriate pharmacological approach.
New real-time image fusion technique for characterization of tumor vascularisation and tumor perfusion of liver tumors with contrast-enhanced ultrasound, spiral CT or MRI: First results
Authors: Jung E.M. , Schreyer A.G. , Schacherer D. , Menzel C. , Farkas S. , Loss M. , Feuerbach S. , Zorger N. , Fellner C.
Published: December 2019

Aim: Evaluation and characterization of the vascularisation and perfusion of liver tumors by means of image fusion of dynamic contrast-enhanced ultrasound (CEUS), multidetector-CT (MD-CT) or magnetic resonance imaging (MRI) with the ultrasound navigation technique.

Material: For interventional planning a real-time image fusion involving CEUS (LOGIQ E9, GE) was performed in 20 patients (12 men, 8 women, age 43–69 years, median 54) with histologically confirmed malignant liver tumors (9 × hepatocellular carcinoma (HCC), 5 × metastases, 2 × hemangiomas, 1 × cholangiocellular carcinoma (CCC), 1 × lymphoma, 1 × neuroendocrine tumor, 1 × focal nodular hypoplasia (FNH)). In 17 patients the real-time CEUS was fused with contrast-enhanced MD-CT and in three patients with contrast-enhanced MRI (Gd-DTPA and liver-specific contrast medium Resovist®). All of the ultrasound examinations were performed by an experienced examiner with a multi-frequency probe (2–5 MHz, LOGIQ E9, GE); dynamic image sequences up to 3 minutes in true agent detection mode of contrast harmonic imaging (CHI) were documented. An evaluation of the tumor was performed by the characterization of the dynamics of the contrast medium and microperfusion with CEUS, fused with MD-CT or MRI.

Results: In 18/20 cases there was an accurate agreement with respect to the segmental localization of the tumor lesion. In 2/20 cases the localization was comparable with the image fusion of CEUS and reference imaging (a total of at least 65 lesions: 3 × 1 lesion, 5 × 2 lesions, 8 × 3 lesions, 2 × 5 lesions, 1 × 8 lesions, 1 × at least 10 lesions (multifocal)). With image fusion a certain characterization was attained in 17/20 cases. In 3/20 cases (lymphoma after liver transplantation, multifocal CCC, metastases of a neuroendocrine tumor) the diagnosis was at first doubtful and had to be confirmed histologically. In patients with HCC an evaluation of the tumor perfusion was feasible in all 9 cases (8/9 after local trans-arterial chemoembolization (TACE), 1/9 after radio frequency ablation (RFA)). A tendency toward the identification of more lesions with image fusion of CEUS and CT than with contrast-enhanced CT alone could be recognized (p=0.059).

Conclusion: Applying a new real-time fusion technique of MD-CT or MRI with CEUS new possibilities for the evaluation, intervention and monitoring of the therapy of liver lesions were made possible, since the method also comprised the dynamic microperfusion.
Permeability of technical and biological tissues
Authors: Franke R.P. , Fuhrmann R. , Hiebl B. , Mrowietz C. , Jung F.
Published: December 2019

The permeability of a material is described by the amount of substances (gases, liquids, particles) passing through pores and/or interstices of the material in a certain time. In medicine and biotechnology the permeability is given usually as the amount of water (ml × cm−2 × min−1) permeating per area and time unit through the material. Vascular prostheses are described e.g. as high porous prostheses (e.g. Dacron™: 1500–4000 (ml × cm−2 × min−1)) or as low porous prostheses (e.g. ePTFE: 200–1000 (ml × cm−2 × min−1)).

The permeability of blood capillaries is characterized by the exchange of nutrients, metabolites and breathing gases. Capillary permeability and the transport of the permeates through tissues are the key processes for the supply of organs and tissues where especially the protein transport through tissues is described by diffusive and/or convective terms.

The vascular permeability is governed by the permeability of the intimal endothelial cells. The major influence is exerted by the interendothelial binding which can change drastically in a very short time. This is demonstrated by the fast development of interstitial lung oedema in case of septical shock. The permeability is an integral indicator of tissue and organ function.

It is possible to assess the permeability of native and engineered tissues precisely with a recently developed system. First results will be shown.
Influence of radiographic contrast media on the secretion of vasoactive substances by primary human umbilical venous endothelial cells (HUVEC): Prospective, controlled, in vitro comparative study
Authors: Franke R.P. , Fuhrmann R. , Hiebl B. , Jung F.
Published: December 2019

Besides the desirable effect of roentgen ray absorption radiographic contrast media (RCM) can also have varying adverse effects. Under discussion, as a possible cause, are microcirculatory disorders resulting from morphological alterations in erythrocytes and endothelial cells.

Therefore, the contrast media-induced release of vasoactive substances (prostacyclin, endothelin-1, and nitric oxide (NO)) from human endothelial cells (HUVEC) induced by two commercially available RCMs (Iodixanol 320, Iomeprol 350) was tested in a controlled in-vitro study.

The results show that RCMs lead to endothelial cell trauma in vitro, which is apparent in the release of prostacyclin and endothelin-1, while NO release was not affected. The endothelin-1 release after incubation with Iodixanol was similar to the release in the control cultures. In comparison, lower endothelin-1 levels were measured in the cultures incubated with Iomeprol at all 3 time points indicating a more significant cell trauma. Prostacyclin release – also an indicator of traumatization of endothelial cells – increased after addition of both contrast agents. The highest release was found after incubation with Iomeprol 350.
Semiquantitative characterization of hepatocellular carcinoma (HCC) – perfusion with contrast-enhanced ultrasound and perfusion analysis
Authors: Schacherer D. , Girlich C. , Wiest R. , Büttner R. , Schölmerich J. , Feuerbach S. , Zorger N. , Hamer O.W. , Jung E.M.
Published: December 2019

Background: At the moment, there is only poor specificity of HCC-detection in tumors smaller than 2 cm in a cirrhotic liver. Thus, efforts have to be made to optimize the distinction between regenerative nodules and HCC.

Aims: The aim of our study was to describe the particular perfusion pattern of hepatocellular carcinoma using a specific quantification software.

Methods: We evaluated 25 patients with proven hepatocellular carcinoma, who underwent dynamic contrast-enhanced ultrasound (CEUS) using a second generation contrast agent (SonoVue®, Bracco, Germany). Retrospectively, we applied the quantification software Qontrast® (Bracco, Milan, Italy) to obtain contrast-enhanced sonographic perfusion maps for each lesion.

Results: We found a close positive correlation of the perfusion parameters peak, time-to-peak and regional blood volume between the entire tumors, the center (center/total) and the periphery of the tumors (periphery/total), respectively. Moreover, we found significant higher peak values, a significant higher regional blood volume and a trend to lower time-to-peak in the center of the tumors compared to the tumor periphery.

Conclusion: These results suggest a better established vascular bed in the center of the tumors. This could be a sonographic marker of HCC in contrast to regenerative nodules.
Effect of vitamin E on reperfusion injuries during reconstructive vascular operations on lower limbs
Authors: Arató E. , Kürthy M. , Sínay L. , Kasza G. , Menyhei G. , Hardi P. , Masoud S. , Ripp K. , Szilágyi K. , Takács I. , Miklós Z. , Bátor A. , Lantos J. , Kollár L. , Rőth E. , Jancsó G.
Published: December 2019

Introduction: The challenge against reperfusion injury and tissue oxidative stress, especially in vascular surgical interventions has an essential importance to reach the optimal clinical result. Numerous experimental attempts have proved the positive antioxidant effect of vitamin E in both chronic and acute phase models. In our study we monitored the effect of continuous preoperative treatment with vitamin E, on oxidative stress and tissue inflammation reactions developed after reconstructive operations.

Patients and methods: 32 patients have been involved in a randomized, prospective study, all suffering from AFS occlusion proved by angiography, and all undergone supragenual reconstruction. Duration of ischemia and amount of tissues under vascular clamping were almost the same in all patients. In the group treated with E-vitamin, we administered 1×200 mg of vitamin E p/o from the preoperative day till the 7th post operative day. Patients of the second group did not receive vitamin E.

Materials and methods: Peripheral blood samples were collected immediately before operation and at the end of the second reperfusion hour (early reperfusion period). Late reperfusion period has been monitored by analyzing blood samples taken at 24th hour and 7th day next to the operative ischemia. Among oxidative stress parameters, direct measurement of reactive oxygen intermediator (ROI) and determination of antioxidant state (GSH, Total-SH group, SOD) have been performed. Malondialdehyde was chosen as marker for lipidperoxidation. Inflammation reactions were monitored up on expression of adhesion molecules (CD11a and CD18). We also controlled the oscillation of myeloperoxidase (MPO) activity.

Results: Our study has proved that preoperative (from the preoperative day till the 7th post operative day) administration of 200 mg vitamin E could reduce the level of oxidative stress developed after ischemic-reperfusion insult (lipidproxidation, antioxidant enzymes). According to our results, the prooxidant-antioxidant imbalance also diminished in the group with E-vitamin treatment. We proved that elective administration of vitamin E could decrease the WBC activity (MPO activity, free radicals production, expression of adhesion molecules) and its consequential local inflammation process, during early reperfusion.
Acute dichlorvos poisoning induces hemorheological abnormalities in rabbits via oxidative stress
Authors: Zhang Xiaolan , Yao Weijuan , Jia Binbin , Sun Dagong , Ka Weibo , He Dongqi , Wang Xifu , Wen Zongyao
Published: December 2019

Dichlorvos is an important insecticide used largely. Some studies have demonstrated that organophosphate pesticide has effects on erythrocyte membrane structures, which is critical to erythrocyte function and hemorheology. The aim of the present study was to explore the effect of oxidative stress on hemorheological changes during dichlorvos poisoning in rabbits. Data indicated that after dichlorvos exposure the hematocrit adjusted viscosity at high shear rate increased and erythrocyte membrane fluidity decreased. Data obtained from plasma showed that lipid peroxidative substance-malonaldehyde was elevated and superoxide dismutase was reduced. In summary, oxidative stress does occur in dichlorvos poisoning and may lead to hemorheological alterations. The changes of hemorheology may be responsible for the pathophysiology of the dichlorvos poisoning.
Effects of ascorbate fatty ester derivatives on erythrocyte membrane lipoperoxidation
Authors: Spengler M.I. , Rasia M. , Palma S. , Allemandi D.
Published: December 2019

6-O-alkyl ascorbic acid esters (ASCn) are amphiphilic molecules that behave as surfactants in aqueous solution. ASCn have shown some physical and rheological properties that suggest a potential utility as drug carriers. The present paper aims to evaluate the effect of ASCn on erythrocyte properties in order to get information regarding the relationship between osmotic fragility, erythrocyte deformability and membrane lipoperoxidation process. The assays were performed at the following concentrations: the critical micelar concentration (CMC), producing 10% hemolysis (CH10) and producing 50% hemolysis (CH50). We observed that ASCn (ASC8, ASC10 and ASC12), at concentration nearby CMC, neither affected cell deformability nor produced lipoperoxidation. Nevertheless, at higher concentrations (CH10 and CH50), the RBCs incubated with ASCn were affected by a significant and progressive loss of deformability, simultaneously with an increase of osmotic fragility and membrane lipoperoxidation.
Prediction of hematocrit and red cell deformability with whole body biological impedance
Authors: Varlet-Marie Emmanuelle , Aloulou Ikram , Mercier Jacques , Brun Jean-Frédéric
Published: December 2019

Bioelectrical impedancemetry has been used to evaluate hemorheological parameters in vitro but whole body impedance measurements are also correlated to some hemorheologic factors, due to their close relationship with determinants of electric properties of blood. In previous studies, we have determined a set of predictive equations for hematocrit, whole blood viscosity and plasma viscosity in both sedentary and trained individuals. In this study we aimed at verifying those findings and investigating for other equations in a sample of 62 subjects whose body composition was assessed with a multifrequency bioelectrical impedancemeter using low intensity at the following frequencies: 1, 5, 10, 50 and 100kHz. Viscometric measurements were done with a falling ball viscometer. Hematocrit was measured with microcentrifuge. We confirm that hematocrit was correlated with impedance measurements at 50 kHz (r=−0.671, p < 0.01), and describe a new predictive equation for RBC rigidity index «k» calculated with the equation of Quemada, (“k” index = 0.0003 Z50 + 1.2815; mean difference: −0.0506; 95% confidence interval of −0.0134 to 0.00324) that is also correlated with impedance measurements at 50 kHz (r = 0.526, p < 0.01). Although the precision of these formulae is not sufficient for allowing true «predictions» of hematocrit and red cell deformability, these findings confirm that factors of viscosity are to some extent reflected by whole body electric properties.
The effect of salvianolic acid B combined with laminar shear stress on TNF-α-stimulated adhesion molecule expression in human aortic endothelial cells
Authors: Xie Li Xia , Durairajan Siva Sundara Kumar , Lu Jia Hong , Liu Chen Li , Kum Wan Fung , Wang Yan , Koo Irene , Wu Wei Kang , Han Dong , Lao Fulong , Huang Jian-Dong , Li Min
Published: December 2019

The study was conducted to investigate the effect of Salvianolic acid B (Sal B) on TNF-α-stimulated adhesion molecule expression i.e. vascular adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and E-selectin in human aortic endothelial cells (HAECs) under laminar shear stress (LSS) condition. Exposure of HAECs to LSS (12 dynes/cm2 for 6 h decreased the TNF-α-induced protein expression of adhesion molecules i.e. VCAM-1, ICAM-1 and E-selectin. Pre-treatment of HAECs with Sal B (10 μg/ml) then exposed to LSS (12 dynes/cm2) for 6 h significantly inhibited VCAM-1, ICAM-1 and E-selectin expression stimulated by TNF-α. Moreover, combined Sal B and LSS treatment inhibited the adhesiveness of monocytic U937 cells to TNF-α-stimulated HAECs. We further examined the molecular mechanisms and found that the combination of Sal B and LSS treatment dramatically inhibited TNF-α-induced NF-κB activation evidenced by IκBα degradation and p65 nuclear translocation in HAECs. This study provides the first biomechanopharmacological evidence that Sal B has a combination effect with LSS to reduce the expression of three adhesion molecules, leading to reduced monocyte adhesion to HAECs, at least in part, by inhibiting the NF-κB signaling pathway. Data from this study thus support the potential clinical application of Sal B in vascular inflammatory diseases.
Relationship between C-reactive protein and early activation of leukocytes indicated by leukocyte antisedimentation rate (LAR) in patients with acute cerebrovascular events
Authors: Molnar Tihamer , Papp Viktoria , Banati Miklos , Szereday Laszlo , Pusch Gabriella , Szapary Laszlo , Bogar Lajos , Illes Zsolt
Published: December 2019

The purpose of this study was to determine the relationship between high-sensitive C-reactive protein (hsCRP) and leukocyte antisedimentation rate (LAR) as a specific test to detect early activation of leukocytes providing the first line of defence against infections in ischemic stroke. In 49 patients with acute ischemic events and 61 healthy subjects (HS), we examined LAR, astroglia specific S100B indicating the extent of brain tissue damage and hsCRP within 6 hours, as well as 24 and 72 hours after onset of symptoms. Serum levels of hsCRP on admission was significantly higher in patients with acute ischemic stroke (AIS) compared to HS and were higher in patients with recurrent to first ever ischemic stroke. Increased basal levels of hsCRP also correlated with severity of stroke and extent of infarct reflected by S100B levels in sera, but did not correlate with post-stroke infections. However, a higher rate of infection was observed among patients, in whom hsCRP was elevated at 72 hours but LAR did not increase. Therefore, such late elevation of hsCRP may indicate pre-clinical infections due to deficient leukocyte activation. Simple tests like LAR and hsCRP may help in predicting outcome and high risk of infectious complications.
No apparent correlation between Behçet’s disease and oxidative stress disturbance
Authors: Saglam Hayrettin , Kaya Eser , Cemek Mustafa , Çiçek Yüksel , Kulac Mustafa , Karaca Semsettin
Published: December 2019

Behçet’s disease (BD) is a chronic, progressive and inflammatory multisystemic disease, that significantly affects the cardiovascular system. Oxidative stress (OS) is a disturbance in oxidant/antioxidant balance in favor of oxidants. The OS that increases acutely and chronically due to the inflammatory process plays an important role in the pathogenesis of the cardiovascular system effects of the disease by causing endothelial dysfunction in vascular structures. The aim of our study was to investigate the relationship between OS and myocardial perfusion, which is based on microvascular dysfunction, in BD. Material and method: Twenty-seven patients with BD (16 M, 11 F, mean age: 38.7 ± 9.4 years) and 22 healthy volunteers (12 M, 10 F, mean age: 35.8 ± 6.5 years) participated in our study. Technetium-99m methoxyisobutylisonitrile single photon emission computed tomography (Tc-99m MIBI SPECT) stress-rest test was performed with two-day protocol. Myocardial perfusion scores (summed stress score, summed rest score, summed difference score, fix defect score) and perfusion defect prevalence (stress, rest, ischemic and fixed) were determined as the percentage of left ventricle. Coronary angiography was performed in patients with abnormal myocardial perfusion scintigraphy. For OS analysis, the blood samples were taken immediately before the first imaging procedure and were studied for malondialdehyde, glutathione, nitrite, nitrate, vitamin C, retinol, and carotene. Results: In the BD group, a total of 9 patients had abnormal findings in their stress and rest electrocardiography. Perfusion defect in myocardial perfusion scintigraphy was observed in 14 patients (51.8%). Twelve patients accepted coronary angiography, and their results were normal. In the comparison of myocardial perfusion scores, perfusion defect prevalence and OS parameters, there was a significant difference between the BD and control groups. In the BD group, no correlation was observed between myocardial perfusion scores, perfusion defect prevalence and OS parameters. Conclusion: Defects in myocardial perfusion and increase in OS were observed in BD; however, there was no correlation between the two findings in the inactive period. In other words, the prevalence and intensity of myocardial perfusion defects can vary at different OS levels.