Clinical Hemorheology and Microcirculation - Volume Pre-press, issue Pre-press

Authors: Schaible, J. | Stroszczynski, C. | Beyer, L.P. | Jung, E.M.

Article Type: Research Article

Abstract: OBJECTIVE: The use of a standardized dynamic contrast enhanced ultrasound (CEUS) protocol to determine perfusion of hepatocellular carcinomas (HCC) using quantitative analysis. METHODS: Retrospective analysis of 27 patients with hepatocellular carcinoma examined by a standardized protocol (bolus injection of 2.4 ml sulphur hexafluoride microbubbles, arterial phase to portal venous phase using continuous CINE-loops over 1 minute, short CINE-loops after 2, 3, 4, 5 and 6 minutes and additional single images for B-mode, CCDS, elastography). The examination was performed by an experienced sonographer with a high resolution, multi-frequency transducer (1–6 MHz). The reading of the reference imaging (contrast enhanced CT and …MRI) and histopathology, if necessary, was performed independently. Retrospective analysis of the CEUS DICOM loops was done using time intensity curves analysis (TIC) with evaluation of the time to peak (TTP) and the area under the curve (AUC). RESULTS: All tumor lesions were characterized by CEUS, based on typical contrast patterns for HCC lesions with arterial enhancement and wash out in the late phase, corresponding to MRI with liver specific contrast agent or contrast enhanced CT. Mean TTP (SD) in the tumor centre (C) was 19.93 (11.31), in the periphery (P) 22.94 (9.44) and in the normal liver tissue (LT) 28.19 (11.34) with significant differences between all zones C/P (p  = 0.013), C/LT (p  = 0.0051) and P/LT (p  = 0.022). AUC mean (SD) in the tumor centre (C) was 660.03 (292.64), in the periphery (P) 586.04 (237.01) and in the normal liver tissue (LT) 484.20 (236.99), also with significant differences between all zones C/P (p  = 0.001), C/LT (p  <  0.001) and P/LT (p  <  0.001). CONCLUSION: TIC-analysis is an easy-to-use tool for the dynamic evaluation of microvascularization in hepatocellular carcinoma and allows a fast and cost-efficient quantitative analysis. Show more

Keywords: CEUS, Contrast enhanced ultrasound, hepatocellular carcinoma, TIC-analysis, quantitative analysis

DOI: 10.3233/CH-199221

Citation: Clinical Hemorheology and Microcirculation, vol. Pre-press, no. Pre-press, pp. 1-10, 2019

Authors: Sun, Xianlei | Tung, Wingtai | Wang, Weiwei | Xu, Xun | Zou, Jie | Gould, Oliver E. C. | Kratz, Karl | Ma, Nan | Lendlein, Andreas

Article Type: Research Article

Abstract: Electrospinning has attracted significant attention as a method to produce cell culture substrates whose fibrous structure mimics the native extracellular matrix (ECM). In this study, the influence of E-modulus of fibrous substrates on the lineage commitment of human adipose-derived stem cells (hADSCs) was studied using fiber meshes prepared via the electrospinning of a polyetheresterurethane (PEEU) consisting of poly(ρ -dioxanone) (PPDO) and poly(ɛ -caprolactone) (PCL) segments. The PPDO: PCL weight ratio was varied from 40:60 to 70:30 to adjust the physiochemical properties of the PEEU fibers. The cells attached on stiffer PEEU70 (PPDO:PCL,= 70:30) fiber meshes displayed an elongated morphology compared to …those cultured on softer fibers. The nuclear aspect ratio (width vs. length of a nucleus) of hADSCs cultured on softer PEEU40 (PPDO:PCL = 40:60) fibers was lower than on stiffer fibers. The osteogenic differentiation of hADSCs was enhanced by culturing on stiffer fibers. Compared to PEEU40, a 73% increase of osteocalcin expression and a 34% enhancement of alkaline phosphatase (ALP) activity were observed in cells on PEEU70. These results demonstrated that the differentiation commitment of stem cells could be regulated via tailoring the mechanical properties of electrospun fibers. Show more

Keywords: Electrospun fibers, polyetheresterurethane, E-modulus, mesenchymal stem cells, osteogenic differentiation

DOI: 10.3233/CH-199206

Citation: Clinical Hemorheology and Microcirculation, vol. Pre-press, no. Pre-press, pp. 1-10, 2019

Authors: Schiltz, Daniel | Taeger, Christian D. | Biermann, Niklas | Ranieri, Marco | Klein, Silvan | Prantl, Lukas | Geis, Sebastian

Article Type: Research Article

Abstract: BACKGROUND: Reconstruction of soft tissue defects with free flaps is a common procedure in plastic and reconstructive surgery. Most postoperative complications occur within the first 48–72 hours after surgery. After postoperative complications, short perfusion restoration times may improve flap survival rates by up to 30–50%. Ratiometric fluorescence imaging is an additional or alternative method of postoperative flap monitoring. OBJECTIVE: To test the efficacy and utility of transepidermal oxygen flux imaging to evaluate postoperative skin oxygenation of free and local flaps in the first 48 hours after surgery. METHODS: The study included 32 patients (aged between 18 …and 80 years; mean age 52.9) with a tissue defect covered with a free flap transplant at the Department of Plastic and Reconstructive Surgery of the University Medical Center Regensburg. Postoperative oxygen flux was measured with the ‘VisiSens system’ placed on the vascular pedicle as well as on the peripheral and central part of the flap. RESULTS: Values of oxygen flux were higher in case of flap congestion (0.069±0.012) or flap necrosis (0.155±0.083) than in cases without any complications (0.061±0.006). Flux values of different areas of the same flap showed only minimal differences (central part: 0.065±0.008, peripheral part: 0.070±0.009, vascular pedicle: 0.056±0.004); the level of significance was p  = 0.904. CONCLUSION: Imaging transepidermal oxygen flux by ratiometric luminescence seems to be a reliable alternative, indirect method of postoperative flap monitoring with regard to microcirculatory function and flap viability. Show more

Keywords: Postoperative free flap monitoring, microcirculatory function, tissue oxygenation, tissue perfusion, flux imaging, flap monitoring, transcutaneous oxygen measurement

DOI: 10.3233/CH-199225

Citation: Clinical Hemorheology and Microcirculation, vol. Pre-press, no. Pre-press, pp. 1-11, 2019

Authors: Schulz, Christian | Kammerer, Sarah | Küpper, Jan-Heiner

Article Type: Research Article

Abstract: BACKGROUND: Human hepatocyte in vitro cell culture systems are important models for drug development and toxicology studies in the context of liver xenobiotic metabolism. Often, such culture systems are used to elucidate the biotransformation of xenobiotics or drugs and further investigate drug and drug metabolite effects on biological systems in terms of potential therapeutic benefit or toxicity. Human hepatocytes currently used for such in vitro studies are mostly primary cells or cell lines derived from liver cancers. Both approaches have limitations such as low proliferation capacity and progressive dedifferentiation found in primary cells or lack of liver functions …in cell lines, which makes it difficult to reliably predict biotransformation of xenobiotics in patients. In order to overcome these limitations, HepaFH3 cells and Upcyte® hepatocytes representing primary-like hepatocytes of the first and second generation are increasingly used. Based on primary human hepatocyte cells transduced for stable expression of Upcyte® proliferation genes, they are mitotically active and exhibit liver functions over an extended period, making them comparable to primary human hepatocytes. These hepatocyte models show active liver metabolism such as urea and glycogen formation as well as biotransformation of xenobiotics. The latter is based on the expression, activity and inducibility of cytochrome P450 enzymes (CYP) as essential phase I reaction components. However, for further characterisation in terms of performance and existing limitations, additional studies are needed to elucidate the mechanisms involved in phase I reactions. One prerequisite is sufficient activity of microsomal NADPH-cytochrome P450 reductase (POR) functionally connected as electron donor to those CYP enzymes. OBJECTIVE: For Upcyte® hepatocytes and HepaFH3 cells, it is so far unknown to what extent POR is expressed, active, and may exert CYP-modulating effects. Here we studied POR expression and corresponding enzyme activity in human hepatoblastoma cell line HepG2 and compared this with HepaFH3 and Upcyte® hepatocytes representing proliferating primary-like hepatocytes. METHODS: POR expression of those hepatocyte models was determined at mRNA and protein level using qRT-PCR, Western Blot and immunofluorescence staining. Kinetic studies on POR activity in isolated microsomes were performed by a colorimetric method. RESULTS: The investigated hepatocyte models showed remarkable differences at the level of POR expression. Compared to primary-like hepatocytes, POR expression of HepG2 cells was 4-fold higher at mRNA and 2-fold higher at protein level. However, this higher expression did not correlate with corresponding enzyme activity levels in isolated microsomes, which were comparable between all cell systems tested. A tendency of higher POR activity in HepG2 cells compared to HepaFH3 (p  = 0.0829) might be present. Compared to primary human hepatocyte microsomes, POR activity was considerably lower in all hepatocyte models. CONCLUSION: In summary, our study revealed that POR expression and activity were clearly detectable in all in vitro hepatocyte models with the highest POR expression in cancer cell line HepG2. However, POR activity was lower in tested hepatocyte models when compared to human primary hepatocyte microsomes. Whether this was caused by e.g. polymorphisms or metabolic differences of investigated hepatocyte models will be target for future studies. Show more

Keywords: Biotransformation, CYP, cytochrome P450 monooxygenase, HepaFH3, HepG2, hepatocytes, NADPH-cytochrome P450 reductase, POR, Upcyte® hepatocytes, xenobiotics

DOI: 10.3233/CH-199226

Citation: Clinical Hemorheology and Microcirculation, vol. Pre-press, no. Pre-press, pp. 1-12, 2019

Authors: Klingelhoefer, Eric | Hesse, Karl | Taeger, Christian D. | Prantl, Lukas | Stepniewski, Adam | Felmerer, Gunther

Article Type: Research Article

DOI: 10.3233/CH-199213

Citation: Clinical Hemorheology and Microcirculation, vol. Pre-press, no. Pre-press, pp. 1-11, 2019

Authors: Ullrich, Helen | Gori, Tommaso

Article Type: Research Article

Abstract: Percutaneous coronary intervention is the most often used method for coronary revascularization. Stenting restores blood perfusion to ischemic areas, but it also causes mechanical disruption of the atheromatous plaque and the nearby endothelium, stimulating the activation of platelets. In a similar way, platelets are activated by thrombin exposure in the setting of plaque rupture. The interaction between platelets, oxidative stress and inflammation is an important factor determining the extent and severity of vascular dysfunction observed in these settings. Platelets activated by the vessel trauma release inflammatory and mitogenic mediators into the vascular microenvironment, activating leukocyte chemotaxis and switching the endothelial …phenotypefrom a quiescent to an activate one. The increased bioavailability of reactive oxygen species from the vessel wall, from leukocytes and from platelets, and the subsequent decreased bioavailability of nitric oxide, further stimulates platelets, which are otherwise inhibited by this endothelial mediator. Thus, inflammation, oxidative stress and platelet activation cooperate in a feed-forward mechanism leading to vascular dysfunction and possibly compromising the effect of stenting. Inhibitors of platelet function have thus important ancillary effects beyond their antithrombotic ones, which will be discussed in the present short review. Show more

Keywords: Endothelium, thrombosis, acute coronary syndromes, stent

DOI: 10.3233/CH-199214

Citation: Clinical Hemorheology and Microcirculation, vol. Pre-press, no. Pre-press, pp. 1-6, 2019

Authors: Asam, Claudia | Buerger, Korbinian | Felthaus, Oliver | Rachel, Reinhard | Prantl, Lukas | Witzgall, Ralph | Aung, Thiha | Haerteis, Silke

Article Type: Research Article

Abstract: BACKGROUND: Doxorubicin is a cytostatic drug from the group of anthracycline antibiotics that is widely used as a chemotherapeutic agent. Side effects of the active substance include cardiotoxicity and nephrotoxicity. Doxorubicin-treated renal epithelial cells and (sarcoma) tumors are examined by correlative light and electron microscopy (CLEM) to investigate the subcellular localization of doxorubicin. METHODS: The kidney epithelial cell line MDCK II (Madin-Darby Canine Kidney) grown on culture dishes were treated with doxorubicin. Subsequently, the cells are analyzed by means of fluorescence and transmission electron microscopy (TEM). In vivo , alveolar rhabdomyosarcoma (RH 30) tumor cells are transferred to …the chorioallantoic membrane (CAM) of the chicken embryo. Doxorubicin is injected into a vein of the chicken embryo. After 24 hours, the tumor is removed and examined using CLEM. RESULTS: The kidney epithelial cells and the doxorubicin-injected tumors show a clear staining of the cell nucleus, which correlates with electron-dense regions (heterochromatin). High-resolution TEM shows that doxorubicin treatment leads to an enormous stress situation with an increased formation of membrane blebbings. CONCLUSIONS: CLEM is a promising new method to visualize the pattern of fluorescing drugs (e.g. doxorubicin) in renal epithelial cells and tumors, and to localize the drug in its subcellular context combined with high resolution. Show more

Keywords: Correlative light and electron microscopy (CLEM), chorioallantoic membrane (CAM), doxorubicin, chemotherapy, tumor, sarcoma, Epon

DOI: 10.3233/CH-199212

Citation: Clinical Hemorheology and Microcirculation, vol. Pre-press, no. Pre-press, pp. 1-11, 2019

Authors: Goetz, J. | Kaisermayer, E. | Haase, H. | Jünger, M. | Riebe, H.

Article Type: Research Article

Abstract: BACKGROUND: Although the efficacy of compression therapy through knee-length compression stockings with an interface pressure of 18–21 mmHg for leg oedemas has been confirmed by many studies, 91% of patients are still treated with a higher interface pressure. METHOD: In this prospective open randomised monocentric study 19 patients (age ≥65, movement restrictions and symptomatic leg oedema) received knee-length compression stockings with an interface pressure of 18–21 mmHg (stocking type 1 ) and 23–32 mmHg (stocking type 2 ). On two consecutive days each of the two compression stocking types were worn for at least 8 hours. After this test period, both …stocking types were assessed subjectively and skin changes were recorded. RESULT: A significantly (p -value <0.001) subjective improvement of the symptoms and complaints based on leg oedema was reported with the knee-length compression stockings. The Stocking type 1 recorded a significantly (p  = 0,045) better wearing comfort. In addition, the Stocking type 2 was significantly too large amongst women in the front foot area (p  = 0.044). The most common side effects were constrictions on the proximal lower leg (stocking type 1 = 73,7% (14/19); stocking type 2 = 78,9% (15/19)). Subjects with arthritis (p  = 0.006), hallux valgus (p  = 0.034) and/or digitus flexus (p  = 0.021) found the socking type 1 significantly more comfortable. CONCLUSION: In order to achieve optimal patient compliance it is recommended to prescribe knee-length compression stockings with an interface pressure of 18–21 mmHg if the following criteria are met: age ≥65 years, female sex, arthritis, digitus flexus (claw toe) or hallux valgus. Show more

Keywords: Chronic leg oedema, compression stocking therapy, chronic venous insufficiency, quality of life, wearing comfort

DOI: 10.3233/CH-199207

Citation: Clinical Hemorheology and Microcirculation, vol. Pre-press, no. Pre-press, pp. 1-12, 2019

Authors: Koch, Christoph | Taeger, Christian | Geis, Sebastian | Lonic, Daniel | Heidekrueger, Paul | Dolderer, Juergen | Bitzinger, Diane | Hirche, Christoph | Prantl, Lukas | Kehrer, Andreas

Article Type: Research Article

Abstract: BACKGROUND: Purpura fulminans (PF) is a distinct form of rare meningococcal septicaemia mostly in childhood which is characterized by high lethality, extensive necroses and mutilations of extremities. Other ethiologies are idiopathic forms or purpura neonatorum, which is marked by deficiency of Protein-C. PF is caused by micro-embolism of the vascular system, followed by quickly spreading necroses of skin and different organs. Modern concepts of intensive care treatment of the acute phase of this disease and early surgical intervention lead to a rising number of surviving patients requiring limb salvage. Aim of this study is to evaluate a possible lower morbidity …and the grade of lower loss of function because of early surgical intervention. PATIENTS AND METHODS: Between the years 1998 and 2017 cases of PF at two large centers for critical wound care, the department of plastic-, hand- and reconstructive surgery of the university hospital of Regensburg and the department of plastic-, hand- and reconstructive surgery of the BG-clinic Ludwigshafen patients were included into our study. We retrospectively examined patients with PF who were stabilized by intensive care medicine and received surgical interventions. After survival of the acute phase (10 days), patients received plastic surgical reconstructions. RESULTS: A total number of eight patients could be included into our study. All patients survived the initial phase (10 days). All patients required plastic-surgical interventions to address extensive skin and soft tissue defects. Flap operations were judged necessary in five cases. Hereby four defects could be reconstructed by free tissue transfer, one with a local flap. Flap survival was 100 percent. One flap required revision of the arterial anastomosis of the flap arteria. Another flap got partial necrosis. One patient died due to multiorgan failure. Early debridements with consequent fasciotomies and secondary plastic-surgical reconstruction achieved good functional results. Limb salvage was accomplished in three patients. One patient died due to fulminant progress of the disease. CONCLUSION: Management of PF requires a multidisciplinary approach and close communication between the different subspecialties. Early debridements with consequent fasciotomies showed good results in salvaging subfascial muscle tissue in the extremities with satisfying functional results. Early surgical intervention is an important factor for improved limb salvage and survival. Show more

Keywords: Purpura fulminans, symptoms, surgical management, intensive care management, Idiopathic Thrombocytopenic Purpura, Disseminated Intravascular Coagulation, Acquired Protein C Deficiency, Sepsis, Neisseria meningitidis, Menigococcal sepsis, streptococcus pyogenes, herpes simplex virus

DOI: 10.3233/CH-190588

Citation: Clinical Hemorheology and Microcirculation, vol. Pre-press, no. Pre-press, pp. 1-12, 2019

Authors: Yi, Dong | Benhua, Xu | Qiong, Cao | Qi, Zhang | Yijie, Qiu | Daohui, Yang | Lingyun, Yu | Wen-Ping, Wang

Article Type: Research Article

Abstract: AIM: To investigate the value of contrast enhanced ultrasound with high resolution linear transducers (HF-CEUS) for differential diagnosis of focal fundal gallbladder (GB) wall thickening. METHODS: A total of 32 patients with incidentally detected focal fundal GB wall thickening were included. After conventional B mode ultrasound (BMUS) examinations, HF-CEUS were performed with a 7.5–12 MHz 9L4 linear transducer (S2000 HELX OXANA unit, Siemens). Two radiologists independently reviewed the HF-CEUS enhancement patterns to determine the differential features between malignancy and benignity with a five-point confidence scale. The diagnostic accuracy of BMUS and HF-CEUS for GB wall thickening was compared. The …final gold standard was surgery with histological examination. RESULTS: Final diagnoses included GB adenocarcinoma (n  = 16), adenomyomatosis (n  = 12), Xanthogranulomatous (n  = 2) and cholecystitis (n  = 2). HF-CEUS features associated with GB adenocarcinoma including arterial phase inhomogeneous hyperenhancement, venous phase hypoenhancement and disruption of GB wall layer structure (P  <  0.05). Two small (5 mm) liver metastasis were confirmed by HF-CEUS during the late phase liver sweep as hypoenhanced lesions. Nonenhanced Rokitansky-Aschoff sinuses were clearly observed in 83.3% focal adenomyomatosis. Overall sensitivity, specificity and accuracy for differentiation between malignant and benign focal fundal GB wall thickening of HF-CEUS and BMUS were 84.3% vs 53.1%, 90.6% vs 59.3% and 87.5% vs 56.2% (P  <  0.005). CONCLUSIONS: CEUS performed with high frequency linear transducers could be a useful alternative in the differential diagnosis of focal fundal GB wall thickening on conventional ultrasound. Show more

Keywords: Gallbladder, contrast enhanced ultrasound (CEUS), linear transducer, differential diagnosis, focal wall thickening

DOI: 10.3233/CH-190697

Citation: Clinical Hemorheology and Microcirculation, vol. Pre-press, no. Pre-press, pp. 1-11, 2019