Clinical Hemorheology and Microcirculation - Volume 70, issue 4

Authors: Zengel, Pamela | Notter, Florian | Clevert, Dirk A.

Article Type: Research Article

Abstract: BACKGROUND: Ultrasound is the method of choice for preoperative evaluation of masses of the parotid glands. However, existing methods do not allow for definite differentiation between the most common benign and malignant tumors. OBJECTIVE: Thus, we evaluated the benefits of Virtual Touch Quantification (VTQ) and Virtual Touch imaging quantification (VTIQ) for improving preoperative evaluation of parotid tumors. METHODS: We investigated eight lymph nodes and 41 tumors of the parotid gland via ultrasound, color Doppler ultrasound, VTIQ and VTQ shear wave imaging. Each examination consisted of pictures and videos, which were evaluated by twelve examiners. Initially, each …examiner predicted whether the mass was benign or malignant based on B-mode and Doppler images. Then each examiner viewed the VTIQ and VTQ shear wave images and reevaluated the predictions, which were then compared with the histopathological outcomes. RESULTS: In tumors, the sensitivity was 36% based only on B-mode and color Doppler sonography, which increased to 42% with the addition of VTIQ and VTQ. Likewise, the specificity also increased from 78% to 85%. CONCLUSIONS: VTQ and VTIQ provide additional data that improve the capability to distinguish between benign and malignant tumors allowing for an increase in both the sensitivity and specificity. Show more

Keywords: Parotid tumors, ultrasound, shear wave, ARFI imaging, Virtual Touch IQ, pleomorphic adenoma

DOI: 10.3233/CH-189312

Citation: Clinical Hemorheology and Microcirculation, vol. 70, no. 4, pp. 457-466, 2018

Authors: Vahldiek, Janis L. | Erxleben, Christoph | Bressem, Keno Kyrill | Gemeinhardt, Ole | Poch, Franz | Hiebl, Bernhard | Lehmann, Kai S. | Hamm, B. | Niehues, Stefan M.

Article Type: Research Article

Abstract: BACKGROUND: Radiofrequency ablation (RFA) is an important treatment option for hepatic tumors and metastases. Post-ablation recurrence rates are reported up to 36.5 percent and seem to depend on tumor size, intrahepatic localization of tumors and adjacent hepatic vessels. Multipolar RFA has the potential to overcome/reduce these limitations. Experimental and standardized data on achievable lesion sizes, influence of hepatic vessels and non-invasive evaluation of complete ablation is still insufficient. OBJECTIVES: The aim of this study was to evaluate the influence of intrahepatic vessels on shape and size of multipolar RF-ablation zones in healthy porcine liver and to evaluate the …appropriateness of immediate post-ablation contrast-enhanced computed tomography (CECT) in detecting RF-ablation dimensions. MATERIAL AND METHODS: We conducted multipolar RFAs in each of the livers of 10 healthy, narcotized and laparotomized domestic pigs by inserting three parallel probes with a constant probe distance and a constant energy supply. In 4 ablations we interrupted hepatic blood flow using Pringle’s maneuver. Immediate post-ablation CECT scans were acquired. After euthanasia the livers were sliced perpendicularly to the probes at the probes’ active centers. CECT scans were reconstructed equivalently in order to compare RF-lesion size and shape to the macroscopic sections. RESULTS: In total, 19 RF-lesions were analyzed. Every RF-lesion that was ablated during physiological liver perfusion showed an irregular and cloverleaf-like shape (n = 15). Interrupting the hepatic blood flow during RFA led to well-defined, round and homogeneous ablation zones which were 3.8 times larger compared to RF-lesions ablated during continuous hepatic perfusion (n = 4). We found an excellent correlation between immediate post-ablation CECT slices and macroscopic sections when comparing RF-lesion diameters and area, although CECT tended to overestimate ablation dimensions. CONCLUSIONS: The interruption of hepatic blood flow using Pringle’s maneuver during multipolar RFA with three applicators significantly reduces heat sink effects of hepatic vessels and generates large and coherent ablation zones. This approach should be considered in each case of ablation planning adjacent to larger hepatic vessels or when ablating larger tumor volumes. Immediate post-ablation CECT has limited value in detecting incomplete RFA periprocedurally. Show more

Keywords: Liver perfusion, animals, catheter ablation, electrodes, imaging, three-dimensional/*methods, multidetector computed tomography, radiography, Interventional/methods, *contrast media

DOI: 10.3233/CH-189313

Citation: Clinical Hemorheology and Microcirculation, vol. 70, no. 4, pp. 467-476, 2018

Authors: Bimpong-Buta, Nana-Yaw | Jirak, Peter | Wernly, Bernhard | Lichtenauer, Michael | Knost, Thorben | Abusamrah, Thaer | Kelm, Malte | Jung, Christian

Article Type: Research Article

Abstract: BACKGROUND: Parabolic flights offer a unique platform for human experiments in short-term weightlessness. It is generally known that human organ systems react to changes of gravity. Yet, little is known about alterations of blood parameters under these conditions with special emphasis on blood rheology. OBJECTIVE: We investigated the alterations of distinct blood parameters after exposure to weightlessness. METHODS: 14 healthy volunteers underwent short-term phases of weightlessness induced by parabolic flight. At different time points (baseline, t2:1 hour after landing, and t3:24 hours after baseline), venous blood was drawn and analyzed. RESULTS: Analysis of red …blood count revealed significant decreases of hemoglobin and hematocrit post flight. While total white blood counts were unaltered, differential subset analysis revealed significant decreases of eosinophil granulocytes and monocytes. Cortisole levels were unchanged and lacked physiologic circadian decrease. Parameters of renal function were found significantly improved (GFR (ml/min/1,73m2 ): Baseline: 105 [89;109], t2:117 [98;125], t3:110 [102;119]; p = 0.0013. In the sense of mild myocytolysis, levels of myoglobin were significantly elevated post-flight with fast recovery to baseline levels. CONCLUSIONS: In the current analysis, significant alterations of blood parameters after exposure to weightlessness could be detected. These results contribute to the understanding of physiologic adaptations of the human body to weightlessness. Show more

Keywords: Blood parameter analysis, weightlessness, parabolic flight

DOI: 10.3233/CH-189314

Citation: Clinical Hemorheology and Microcirculation, vol. 70, no. 4, pp. 477-486, 2018

Authors: Kauffmann, Philipp | Troeltzsch, Markus | Brockmeyer, Phillipp | Bohnenberger, Hanibal | Heidekrüger, Paul I. | Manzke, Marietta | Canis, Martin | Gaayathiri, Suntharalingam | Schliephake, Henning | Prantl, Lukas | Aung, Thiha

Article Type: Research Article

Abstract: INTRODUCTION: The oral squamous cell carcinoma (OSCC) is a leading cause of death in human malignancies. The aim of this study is to integrate the CAM Assay as a reliable and good working in vivo model for the evaluation of OSCC tumor samples and its growth into the clinical work flow. MATERIAL AND METHODS: Fresh human Tumor samples (OSCCs) 1×1 cm in size were cut into 350–450μ m thick slices by a Vibratome and put on the prepared CAM model. After growth of the tumor tissue on the CAM, we started with topical induction of proinflammatory cytokines (TNFα …) and growth factors (TGFβ ). After further growth of the tumor on the assay, we explanted the tumor tissue and first performed microscopic and then immunohistochemical examinations. E-cadherin and vimentin were used as Epithelial-to-mesenchymal transition (EMT) -makers and the histologic preparations were evaluated histomorphometrically. The results were correlated with clinical parameters of the patients. RESULTS: Under TNFα , the small tumors (T1 / T2) show higher E-cadherin expression than larger tumors (T3 / T4). The vimentin expression under TNFα behaved in the opposite direction, at T1 / T2 the expression decreased in T3 / T4 increased. Furthermore, an increased E-cadherin expression in N0 and diminished E-cadherin expression in N1 / N2b patients could be detected depending on the N-stage of the patients. Vimentin, on the other hand, was reduced in the N0 group and expressed more frequently in the N1 / N2b group. TGFβ induction also led to increased expression of vimentin in the T3 / T4 tumors and N1 / N2b stages. CONCLUSION: By integrating a CAM assay into the clinical workflow, tumors with preserved tumor architecture can be cultured and subjected to histological and molecular biology studies. Effects on biological behavior are recognizable and demonstrable in this model. The key markers E-cadherin and vimentin alone are not sufficient to represent the complexity of the EMT in this model. Further molecular biology and signaling pathway analyzes are necessary. Show more

DOI: 10.3233/CH-189315

Citation: Clinical Hemorheology and Microcirculation, vol. 70, no. 4, pp. 487-494, 2018

Authors: Rieger, Juliane | Hopperdietzel, Carsten | Kaessmeyer, Sabine | Slosarek, Ilka | Diecke, Sebastian | Richardson, Ken | Plendl, Johanna

Article Type: Research Article

Abstract: BACKGROUND: Human and equine patients are known to frequently develop vascular complications, particularly thrombosis both in veins and arteries as well as in the microvasculature. OBJECTIVE: The aim of the present study was to investigate and compare the angiogenic response of human and equine endothelial cells to lesions in an in vitro scratch assay. METHODS: Endothelial cells from human umbilical vein (HUVEC), abdominal aorta (HAAEC) and dermal microvasculature (HDMEC) as well as equine carotid artery (EACEC) and jugular vein (EVJEC) were cultured and an elongated defect was created (scratch or “wound”). Cultures were monitored over …a period of 90 hours in a live cell imaging microscope. RESULTS: In the human endothelial cell cultures, there was a uniform and continuous migration of the cells from the scratch fringe into the denuded area, which was closed after 17 (HUVEC), 15 (HAAEC) and 26 (HDMEC) hours. In the equine endothelial cell cultures, a complete closure of the induced defect occurred after 17 (EVJEC) and 35 (EACEC) hours. CONCLUSIONS: In the equine arterial cells, the delay in closure of the denuded area seems to be the results of a disoriented and uncoordinated migration of endothelial tip cells resulting in slow re-endothelialization. Show more

Keywords: Equine, horse, human, endothelial cells, life cell imaging, scratch assay, wound healing, angiogenesis, cell migration, collective cell migration

DOI: 10.3233/CH-189316

Citation: Clinical Hemorheology and Microcirculation, vol. 70, no. 4, pp. 495-509, 2018

Authors: Krüger-Genge, Anne | Dietze, Stefanie | Yan, Wan | Liu, Yue | Fang, Liang | Kratz, Karl | Lendlein, Andreas | Jung, Friedrich

Article Type: Research Article

Abstract: BACKGROUND: The formation of a functionally-confluent endothelial cell (EC) monolayer affords proliferation of EC, which only happens in case of appropriate migratory activity. AIM OF THE STUDY: The migratory pathway of human umbilical endothelial cells (HUVEC) was investigated on different polymeric substrates. MATERIAL AND METHODS: Surface characterization of the polymers was performed by contact angle measurements and atomic force microscopy under wet conditions. 30,000 HUVEC per well were seeded on polytetrafluoroethylene (PTFE) (θ adv  = 119°±2°), on low-attachment plate LAP (θ adv  = 28°±2°) and on polystyrene based tissue culture plates (TCP, θ adv  = 22°±1°). HUVEC tracks (trajectories) …were recorded by time lapse microscopy and the euclidean distance (straight line between starting and end point), the total distance and the velocities of HUVEC not leaving the vision field were determined. RESULTS: On PTFE, 42 HUVEC were in the vision field directly after seeding. The mean length of single migration steps (SML) was 6.1±5.2 μm, the mean velocity (MV) 0.40±0.3 μm·min-1 and the complete length of the trajectory (LT) was 710±440 μm. On TCP 82 HUVEC were in the vision field subsequent to seeding. The LT was 840±550 μm, the SML 6.1±5.2 μm and the MV 0.44±0.3 μm·min-1 . The trajectories on LAP differed significantly in respect to SML (2.4±3.9 μm, p  < 0.05), the MV (0.16±0.3 μm·min-1 , p  < 0.05) and the LT (410±300 μm, p  < 0.05), compared to PTFE and TCP. Solely on TCP a nearly confluent EC monolayer developed after three days. While on TCP diffuse signals of vinculin were found over the whole basal cell surface organizing the binding of the cells by focal adhesions, on PTFE vinculin was merely arranged at the cell rims, and on the hydrophilic material (LAP) no focal adhesions were found. CONCLUSION: The study revealed that the wettability of polymers affected not only the initial adherence but also the migration of EC, which is of importance for the proliferation and ultimately the endothelialization of polymer-based biomaterials. Show more

Keywords: Endothelial cells, migration, polymer-based biomaterials, cytokine release

DOI: 10.3233/CH-189317

Citation: Clinical Hemorheology and Microcirculation, vol. 70, no. 4, pp. 511-529, 2018

Authors: Nie, Yan | Wang, Weiwei | Xu, Xun | Zou, Jie | Bhuvanesh, Thanga | Schulz, Burkhard | Ma, Nan | Lendlein, Andreas

Article Type: Research Article

Abstract: Bioengineered cell substrates are a highly promising tool to govern the differentiation of stem cells in vitro and to modulate the cellular behavior in vivo . While this technology works fine for adult stem cells, the cultivation of human induced pluripotent stem cells (hiPSCs) is challenging as these cells typically show poor attachment on the bioengineered substrates, which among other effects causes substantial cell death. Thus, very limited types of surfaces have been demonstrated suitable for hiPSC cultures. The multilayer coating approach that renders the surface with diverse chemical compositions, architectures, and functions can be used to improve the …adhesion of hiPSCs on the bioengineered substrates. We hypothesized that a multilayer formation based on the attraction of molecules with opposite charges could functionalize the polystyrene (PS) substrates to improve the adhesion of hiPSCs. Polymeric substrates were stepwise coated, first with dopamine to form a polydopamine (PDA) layer, second with polylysine and last with Laminin-521. The multilayer formation resulted in the variation of hydrophilicity and chemical functionality of the surfaces. Hydrophilicity was detected using captive bubble method and the amount of primary and secondary amines on the surface was quantified by fluorescent staining. The PDA layer effectively immobilized the upper layers and thereby improved the attachment of hiPSCs. Cell adhesion was enhanced on the surfaces coated with multilayers, as compared to those without PDA and/or polylysine. Moreover, hiPSCs spread well over this multilayer laminin substrate. These cells maintained their proliferation capacity and differentiation potential. The multilayer coating strategy is a promising attempt for engineering polymer-based substrates for the cultivation of hiPSCs and of interest for expanding the application scope of hiPSCs. Show more

Keywords: Polymeric substrate, surface coating, induced pluripotent stem cells, cell adhesion

DOI: 10.3233/CH-189318

Citation: Clinical Hemorheology and Microcirculation, vol. 70, no. 4, pp. 531-542, 2018

Authors: Salha, Sonia | Gehmert, Sebastian | Brébant, Vanessa | Anker, Alexandra | Loibl, Markus | Prantl, Lukas | Gehmert, Sanga

Article Type: Research Article

Abstract: INTRODUCTION: Mesenchymal stem cells (MSCs) have been described in breast cancer models to migrate towards carcinoma and integrate into tumor associated stroma supporting tumor growth, increasing their metastatic potency and contributing to tumor-angiogenesis. Platelet-derived growth factor (PDGF) isoforms (AA, BB, CC) stimulate growth, survival and motility of MSCs and certain other cell types. Noteworthy, breast carcinomas are known to express PDGF. We aim to further shed light on i) the relevance of the different PDGF isoforms on adipose tissue derived stem cells (ASCs) migration and ii) the underlying pathway dependent on PDGF stimulation. MATERIALS AND METHODS: Breast cancer …cell lines were purchased and ASC’s were isolated from murine subcutaneous adipose tissue. The transmigration of ASC’s towards the PDGF-isoforms was assessed by using recombinant human PDGF-AA, PDGF-BB and PDGF-CC in a trans-well culture dish system. Transmigrated ASC’s were quantified in 5 randomly selected fields per condition using fluorescence microscopy after calcein-staining. PDGF-BB depended transmigration of ASC’s was verified by downregulation and overexpression of PDGF-BB in breast cancer cell line using lentiviral vectors. In addition, a PI3-kinase inhibitor (LY294002) and a MAP-kinase inhibitor (PD98059) were used to identify the pathway involved in the PDGF-BB mediated migration of ASC’s towards tumor. RESULTS: ASC’s transmigration significantly increased towards PDGF AA at 50 ng and only showed further increase by 500 ng which was similar to cell behavior when exposed to PDGF CC. In comparison, PDGF-BB significantly increased ASC’s transmigration already at a low level of 5 ng with further significant increase for 20 ng and 40 ng. Cell transmigration was blocked with PDGFR-α antibodies but only for PDGF-AA and PDGF-CC whereas PDGFR-β blockage showed a significant effect on transmigration for PDGF-BB and PDGF-CC but not for PDGF-AA. Neutralizing antibodies in combination with PDGF receptor blockage confirmed findings. In addition, only PI3-kinase inhibitor but not the MEK-1 selective inhibitor caused a significant decrease of transmigration for ASCs towards breast cancer cells. DISCUSSION: The transmigration of ASC’s is most significantly enhanced by PDGF-BB via the PI3-kinase pathway. This data support that PI3-kinase is an important key player for MSC migration towards malignancy which need further research to prevent tumor progression in early disease stage. Show more

Keywords: Mesenchymal stem cells, migration, breast cancer, PDGF-BB, PI3K pathway

DOI: 10.3233/CH-189319

Citation: Clinical Hemorheology and Microcirculation, vol. 70, no. 4, pp. 543-551, 2018

Authors: Zhou, Juan | Yang, Hyewon | Lehmann, Christian

Article Type: Research Article

Abstract: Sepsis is a medical condition caused by dysregulated systemic inflammatory response against infection, resulting in high mortality. Despite intensive research over the last few decades, the results from multiple clinical trials targeting specific inflammatory mediators have been disappointing. In the present study, we investigated the role of G protein-coupled receptor GPR55 modulation on immune response in an experimental sepsis model (endotoxemia). Immune response was evaluated by analyzing leukocyte-endothelial interactions and capillary perfusion in the intestinal microcirculation using intravital microscopy. In addition, the levels of plasma inflammatory cytokines were measured. The results demonstrated that GPR55 inhibition using antagonists, CID16020046 or O-1918, …significantly reduced leukocyte adherence in intestinal submucosal venules and decreased proinflammatory cytokine TNF-α and IL-6 production. These data suggest that GPR55 inhibition may be a novel therapeutic target for attenuating hyperinflammation during sepsis. Show more

Keywords: Experimental sepsis, GPR55, microcirculation, immune response

DOI: 10.3233/CH-189320

Citation: Clinical Hemorheology and Microcirculation, vol. 70, no. 4, pp. 553-561, 2018

Authors: Kammerer, Sarah | Küpper, Jan-Heiner

Article Type: Research Article

Abstract: BACKGROUND: Drug induced liver injury (DILI) is the most frequent cause for failure of new drugs in clinical studies. Thus, toxicity studies are indispensable during drug development. The proliferative human liver cell strain HepaFH3 with promising primary-like cellular properties might be a suitable liver model for such studies, but its cytochrome-P450 (CYP) expression is still in low ranges compared to freshly isolated primary human hepatocytes. OBJECTIVE: We aimed to optimize the induction protocol for CYP1A2 and CYP3A4 in HepaFH3 to obtain a physiologically relevant in vitro liver model. METHODS: CYP1A2 and CYP3A4 …were induced by omeprazole and rifampicin, respectively. Induction of the two CYPs was measured by qRT-PCR, immunofluorescence and by P450 Glo enzyme activity assays. RESULTS: The optimized protocol made the experimental design six days shorter than the original procedure. CYP1A2 mRNA levels were induced 118-fold, CYP3A4 levels 36-fold. This result was also reflected at protein level. Enzymatic activity of CYP1A2 increased 3.7-fold and CYP3A4 activity increased 9.8-fold after induction. CONCLUSIONS: We succeeded in optimizing the induction protocol for HepaFH3 to such an extent that CYP1A2 and CYP3A4 are expressed in sufficient amounts that the cell strain can be used as a physiological relevant human liver model for in vitro toxicology studies. Show more

Keywords: Cytochrome P450, CYP induction, DILI, drug induced liver injury, HepaFH3, liver in vitro model, liver toxicity

DOI: 10.3233/CH-189321

Citation: Clinical Hemorheology and Microcirculation, vol. 70, no. 4, pp. 563-571, 2018