Wolfgang Schöber

The effects of paclitaxel on the three phases of restenosis: smooth muscle cell proliferation, migration, and matrix formation: an in vitro study.

Purpose:We sought to evaluate the growth-modulating potential of paclitaxel on cultured human arterial smooth muscle cells depending on the administered dose Material and Methods:For all experiments human arterial smooth muscle cells (SMCs) were used. SMCs were either cultured for 5 days or for 20 days with paclitaxel (doses: 10−7 M, 10−8 M, 10−9 M). For a total period of 20 days, proliferation kinetics of the SMC were analyzed. To assess the clonogenic activity of the SMC colony-forming assays were performed. Drug- and dose-dependent cell cycle changes were analyzed by flow cytometry. The effect on cell migration was examined in a 2-chamber migration system. The effects of paclitaxel on the synthesis of tenascin were examined via immunofluorescence. Results:Depending on the dose administered, paclitaxel proved to inhibit SMC proliferation effectively when administered during the total period of 20 days. When incubated for 5 days with doses of paclitaxel ranging between 10−8 M and 10−9 M, SMCs showed clear signs of regeneration. When being incubated with 10−7 M of paclitaxel, however, SMCs reacted with a reduction in cell proliferation, a reduced clonogenic activity, and a drug-induced G2/M phase block. SMC migration was inhibited effectively as well as extracellular matrix formation. Conclusion:Paclitaxel is a potent inhibitor of SMC proliferation, SMC migration, and extracellular matrix formation in vitro, with all three phases of the restenosis process inhibited effectively.

All-trans and 9-cis retinoid acids inhibit proliferation, migration, and synthesis of extracellular matrix of human vascular smooth muscle cells by inducing differentiation in vitro.

The aim of this study was to evaluate the effects of 9-cis retinoid acid (9-cis RA) and all-trans RA (ATRA) on proliferation, migratory ability, synthesis of extracellular matrix, intracellular signal transduction, and differentiation of human aortic smooth muscle cells (haSMCs) in vitro. Changes of cell proliferation following incubation with RAs in different doses (10−6M, 10−7M, and 10−8M) were determined directly by proliferation kinetics and indirectly by bromodeoxyuridine enzyme-linked immuno sorbant assays and colony-formation assays. The migratory ability of haSMCs was examined with the help of migration assays. The production of the extracellular matrix protein tenascin was explored by immunostaining. The amounts of total p44/p42 mitogen-activated protein kinases (MAPKs) and their phosphorylated forms were detected with the help of Western blots. To judge the state of differentiation of haSMCs, cell cycle distribution and the pattern of &agr;-actin were analyzed. Both RAs clearly inhibited the proliferation of haSMCs in a dose-dependent manner. 9-cis RA had a tendency to be more effective than ATRA. After treatment with RAs, the migratory ability was especially reduced during stimulation with platelet-derived growth factor (PDGF) and the synthesis of tenascin decreased. Although the total p44/p42 MAPKs were downregulated, the amounts of activated forms increased markedly in the cells incubated with RAs and particularly stimulated with PDGF. The cell-cycle analysis demonstrated an increased G1-phase, complemented by a stronger expression of &agr;-actin after treatment. 9-cis RA especially has the potential to inhibit the proliferation, migration, and synthesis of extracellular matrix of haSMCs by inducing differentiation in vitro.

Clinical evaluation of a computer simulated prediction model of contrast enhancement of the liver in spiral CT.

OBJECTIVE A software program was developed simulating a compartmental model of blood circulation based on differential equations. The aim of this study was to compare software-simulated levels of hepatic enhancement with the true values in patients and to test how many patients reach the simulated hepatic enhancement level. METHODS As software program the CT application software carebolus 2 (Siemens, Forchheim, Germany) was used. Hepatic contrast-enhancement curves were simulated prior to CT examinations to evaluate a patient specific time delay after contrast application. At the time delay, when the simulation curve showed an enhancement threshold of 40 Hounsfield Units (HU), the CT spiral scan was started applying 120 ml contrast media with 2 ml/s. The simulated curves were compared with the empiric curves of each patient. RESULTS 25 of 28 patients (89%) achieved 40 HU. The mean enhancement of empiric patients curves was 46.32 +/- 11.9 HU, the mean simulated enhancement was 46.62 +/- 4.3 HU S.D. (P= 0.48). 4.4 values per patient liver could be compared with the simulation curve (122 points for 28 patients): 50% of the patient curves were within a range of 5 HU compared with the simulation curve. CONCLUSION Software simulation of contrast enhancement curves of the liver is a feasible and valuable method to predict individual liver enhancement curves. Improvements concerning the integration of cardiovascular parameters and preexisting liver parenchymal diseases into the simulation software have to be arranged.

Vertebral artery dissection presenting with ispilateral acute C5 and C6 sensorimotor radiculopathy: A case report

Spinal manifestations of vertebral artery dissection (VAD) are rare events and are typically symptomatic with neck pain and ischemic brain injury. We report a patient presenting with unusual peripheral paresis of the right upper limb due to an intramural hematoma of the right vertebral artery with local compression of C5 and C6 as the cause of cervical radiculopathy. These symptoms completely resolved after anticoagulation and physical therapy.

Rhenium-188 for inhibition of human aortic smooth muscle cell proliferation

PURPOSE To evaluate dose-dependent growth-modulating effects of the beta-gamma emitter Rhenium-188 on cultured human aortic smooth muscle cells (haSMC). METHODS AND MATERIALS HaSMC were plated in 25 cm(2) flasks. Two days after plating, cells were incubated with the Re-188 (beta E(max) 2.12 MeV, tissue range(max) < 10 mm, T(1/2) 17 h) for five days. The doses administered were 0.2 Gy, 1, 4, 6, 8, 16, and 32 Gy. After five days, the radionuclide was removed. Cell growth, cell cycle distribution, and clonogenic activity were analyzed for the following 25 days. RESULTS The 0.2 and 1 Gy groups did not show relevant growth-inhibiting effects compared to the control groups. The 4 to 32 Gy groups presented dose-dependent growth inhibition, with a complete growth arrest of the 16 and 32 Gy groups. Clonogenic activity of the smooth muscle cell was strongly inhibited from doses > or =8 Gy. Flow cytometry showed a lasting dose-dependent G2/M phase block. CONCLUSION Smooth muscle cell (SMC) growth can be controlled effectively with Re-188 for at least 25 days after radiation in vitro. As the first four weeks after arterial angioplasty are crucial concerning neointimal formation, Re-188 may be a valuable radionuclide to inhibit restenosis after arterial angioplasty.

Flufenamic acid: Growth modulating effects on human aortic smooth muscle cells in vitro

PURPOSE The aim of the study was to examine the effects of flufenamic acid on proliferation, clonogenic activity, migratory ability, cell-cycle distribution, and p44/42-mitogen-activated protein kinase (MAPK) expression on serum-stimulated human aortic smooth muscle cells (haSMCs) in vitro. MATERIALS AND METHODS HaSMCs were treated with flufenamic acid in three different doses (40 micromol/L, 200 micromol/L, 400 micromol/L) for 4 days, and then flufenamic-acid-free culture medium was supplemented every 4 days until day 20 after initial treatment. The growth kinetics were assessed. Cell-cycle analysis was performed by flow cytometry. The clonogenic activity was evaluated with use of colony formation assays. The migratory ability was investigated by stimulation with platelet derived growth factor (PDGF-BB) in 24 well plates with 8-microm pore membrane inserts. The p44/42 MAPK was detected by Western blot technique. RESULTS Flufenamic acid inhibited the proliferation (400 micromol/L treatment over 4 d; 179,700 +/- 49,800 vs 747,900 +/- 144,000; P <.001), clonogenic activity (400 micromol/L treatment over 4 d; 1 +/- 0.3 vs 50 +/- 1.4; P <.001) and migratory ability (400 micromol/L treatment over 4 d; 8 cells +/- 2 vs 48 cells +/- 15; P <.001) of haSMCs in a dose-dependent manner. Cell-cycle analysis revealed a G2/M-phase block (400 micromol/L treatment over 4 d; 28.9 +/- 1.5 vs 9.5 +/- 3.2; P <.001). The expression of p44/42 MAPK was reduced for a treatment with 400 micromol/L flufenamic acid (controls, 427 BLU +/- 0.305 vs treatment group, 190 BLU +/- 106; P <.05) CONCLUSION Flufenamic acid inhibits the proliferation and migration of haSMCs. Further experiments with animal models concerning stenosis and restenosis are necessary to evaluate the potential of this promising drug.

Impact of glafenine hydrochloride on human endothelial cells and human vascular smooth muscle cells: a substance reducing proliferation, migration and extracellular matrix synthesis.

The aim of this study was to examine the effects of glafenine hydrochloride (a nonsteroidal anti‐inflammatory drug) on proliferation, clonogenic activity, cell‐cycle, migration, and the extracellular matrix protein tenascin of human aortic smooth muscle cells (haSMCs) and human endothelial cells (ECs) in vitro.

Meclofenamic Acid for Inhibition of Human Vascular Smooth Muscle Cell Proliferation and Migration: An In Vitro Study

AbstractPurpose: The aim of the study was to examine the effects of meclofenamic acid on proliferation, clonogenic activity, migratory ability, cell cycle distribution and p44/42 MAPK (mitogen activated protein kinase) expression in serum-stimulated human aortic smooth muscle cells (haSMCs). Methods: haSMCs were treated with meclofenamic acid in three different concentrations (10 mM, 100 mM, 200 mM) for 4 days. Then meclofenamic acid-free culture medium was supplemented until day 20. Growth kinetics were assessed. Cell cycle analysis was performed by flow cytometry. Clonogenic activity was evaluated with colony formation assays. Migratory ability was investigated by stimulation with platelet-derived growth factor (PDGF-BB) in 24-well plates with 8 mm pores membrane inserts. p44/42 MAPK was detected by Western blot technique. Results: Meclofenamic acid inihibited the proliferation, clonogenic activity and migratory ability of haSMCs in a dose-dependent manner. Cell cycle analysis revealed a G2/M-phase block. The p44/42 MAPK was significantly reduced. Conclusion: Meclofenamic acid inhibits the proliferation and migration of haSMCs. If a sufficient dose of meclofenamic acid can be applied systemically or by local drug delivery it could be a valuable substance to prevent restenosis after angioplasty.

Virtual bronchoscopy: comparison of different surface rendering models.

The aim of this study was to compare different representation models of surface-rendered virtual bronchoscopy. 10 consecutive patients with inoperable primary lung tumors underwent thin-section spiral computed tomography. The structures of interest, the tracheobronchial system and anatomical and pathological thoracic structures were segmented using an interactive threshold interval volume-growing segmentation algorithm and visualized with the aid of a color-coded surface rendering method. For virtual bronchoscopy, the tracheobronchial system was visualized using a triangle-surface rendering model, a shaded-surface rendering model and a transparent shaded-surface rendering model. The triangle-surface rendering model allowed optimum detailed spatial representation of the dimensions of extraluminal anatomical and pathological mediastinal structures. As the lumen of the tracheobronchial system was less well defined, the rendering model was of limited use for depiction of the airway surface. The shaded-surface rendering model facilitated an optimum assessment of the airway surface, but the mediastinal structures could not be depicted. The transparent shaded-surface rendering model provides simultaneous adequate to optimum visualization and assessment of the intraluminal airway surface and the extraluminal mediastinal structures as well as a quantitative assessment of the spatial relationship between these structures. Fast data acquisition with a multi-slice detector spiral computed tomography scanner and the use of virtual bronchoscopy with the transparent shaded-surface rendering model obviate the need for time consuming detailed analysis and presentation of axial source images by providing improved the diagnostic imaging of endotracheal and endobronchial diseases and offering a useful alternative to fiberoptic bronchoscopy.

Antiproliferative effects of the antiallergic agent azelastine on human aortic smooth-muscle cells: an in vitro study.

Schöber W, Wiskirchen J, Kehlbach R, et al. Antiproliferative effects of the antiallergic agent azelastine on human aortic smooth-muscle cells: an in vitro study. Invest Radiol 2002;37:248–253. rationale and objectives. The aim of the study was to examine the effects of azelastine on proliferation, clonogenic activity, cell-cycle, and migration of human aortic smooth-muscle cells (haSMCs) in vitro. methods. HaSMCs were treated for 4 days with azelastine (1 &mgr;mol/L, 25 &mgr;mol/L, 50 &mgr;mol/L). Half of the treated groups were incubated again with azelastine, the other half received azelastine-free medium every 4 days until day 20. The growth kinetics and clonogenic activity were assessed. The cell-cycle distribution was investigated by FACS - analysis and the migratory ability was evaluated. results. Azelastine inhibited the proliferation and the clonogenic activity of haSMCs in a dose dependent manner. A G2/M-phase block was induced and the migratory ability was significantly impaired. conclusion. Azelastine has the potential to inhibit the proliferation of haSMCs. If a sufficient dose can be applied either systemically or locally it could be a valuable substance to prevent restenosis.