Automatic Actin Filament Quantification of Osteoblasts and Their Morphometric Analysis on Microtextured Silicon-Titanium Arrays

Microtexturing of implant surfaces is of major relevance in the endeavor to improve biorelevant implant designs. In order to elucidate the role of biomaterial’s topography on cell physiology, obtaining quantitative correlations between cellular behavior and distinct microarchitectural properties is in great demand. Until now, the microscopically observed reorganization of the cytoskeleton on structured biomaterials has been difficult to convert into data. We used geometrically microtextured silicon-titanium arrays as a model system. Samples were prepared by deep reactive-ion etching of silicon wafers, resulting in rectangular grooves (width and height: 2 µm) and cubic pillars (pillar dimensions: 2 × 2 × 5 and 5 × 5 × 5 µm); finally sputter-coated with 100 nm titanium. We focused on the morphometric analysis of MG-63 osteoblasts, including a quantification of the actin cytoskeleton. By means of our novel software FilaQuant, especially developed for automatic actin filament recognition, we were first able to quantify the alterations of the actin network dependent on the microtexture of a material surface. The cells’ actin fibers were significantly reduced in length on the pillared surfaces versus the grooved array (4–5 fold) and completely reorganized on the micropillars, but without altering the orientation of cells. Our morpho-functional approach opens new possibilities for the data correlation of cell-material interactions.     

Preoperative staging of rectal cancer by endoluminal ultrasoundvs. magnetic resonance imaging

PURPOSE: The aim of this study was to compare the value of endoluminal ultrasonography (ELUS) with magnetic resonance imaging (MRI) for preoperative staging of rectal carcinoma. METHODS: Thirty-seven consecutive patients were examined by ELUS and MRI. Imaging results were compared with pathohistologic studies. A tumor extending beyond the bowel wall was considered to be positive and one within the bowel wall was considered negative. Lymph node involvement was considered present if nodes equal to or greater than 5 mm in diameter were found in the perirectal tissue. For evaluating the differences between the two methods, the Mc Nemar test was performed. RESULTS: T-Staging was correct in 88.2 percent (30/34) of patients by ELUS and in 82.3 percent (28/34) by MRI (difference not significant). N-Staging was correct in 80 percent (20/25) by ELUS and in 60 percent (15/25) by MRI (difference of borderline significance). A comprehensive preoperative staging (T + N) was made correctly in 68 percent (17/25) by ELUS and in 48 percent only (12/25) by MRI (difference not significant). CONCLUSIONS: We suggest that ELUS and MRI must be evaluated within the framework of established parameters when treatment modalities such as preoperative radiation therapy and local or radical surgical approach must be decided.     

TIPS for acute and chronic Budd-Chiari syndrome: a single-centre experience

BACKGROUND/AIMS: Transjugular intrahepatic portosystemic shunt (TIPS) is a technically challenging but feasible treatment for Budd-Chiari syndrome (BCS). However, information about the outcome, particularly in patients with liver failure, is scarce. We report our experience of TIPS for BCS. METHODS: Fifteen patients with BCS underwent TIPS. Eight had hepatic failure and seven underwent TIPS for BCS uncontrolled by medical treatment. RESULTS: Fourteen out of 15 had successful TIPS placement. Out of the eight hepatic failure patients, four died soon after TIPS: one liver rupture, one portal vein rupture, one liver failure and one pulmonary oedema. Another patient had a significant intrahepatic haematoma, which resolved with conservative management. TIPS was successfully placed in all of the seven patients with chronic BCS, in whom there was an average follow-up of 20 months. Ascites resolved and liver function improved in all. One patient died after 18 months from the original hepatic metastatic disease. Four patients have had evidence of TIPS dysfunction requiring three balloon dilatations and one restenting. No patient has required liver transplantation. CONCLUSIONS: TIPS should be the first line treatment for BCS uncontrolled by medical therapy. However, mortality in BCS with hepatic failure is high and liver transplantation could be a better option.