Gentamicin supplemented polyvinylidenfluoride mesh materials enhance tissue integration due to a transcriptionally reduced MMP-2 protein expression

<p>Abstract</p> <p>Background</p> <p>A beneficial effect of gentamicin supplemented mesh material on tissue integration is known. To further elucidate the interaction of collagen and MMP-2 in chronic foreign body reaction and to determine the significance of the MMP-2-specific regulatory element (RE-1) that is known to mediate 80% of the MMP-2 promoter activity, the spatial and temporal transcriptional regulation of the MMP-2 gene was analyzed at the cellular level.</p> <p>Methods</p> <p>A PVDF mesh material was surface modified by plasma-induced graft polymerization of acrylic acid (PVDF+PAAc). Three different gentamicin concentrations were bound to the provided active sites of the grafted mesh surfaces (2, 5 and 8 μg/mg). 75 male transgenic MMP-2/LacZ mice harbouring the LacZ reporter gene under control of MMP-2 regulatory sequence -1241/+423, excluding the RE-1 were randomized to five groups. Bilateral of the abdominal midline one of the five different meshes was implanted subcutaneously in each animal. MMP-2 gene transcription (anti-ß-galactosidase staining) and MMP-2 protein expression (anti-MMP-2 staining) were analyzed semiquantitatively by immunohistochemistry 7, 21 and 90 days after mesh implantation. The collagen type I/III ratio was analyzed by cross polarization microscopy to determine the quality of mesh integration.</p> <p>Results</p> <p>The perifilamentary ß-galactosidase expression as well as the collagen type I/III ratio increased up to the 90^thday for all mesh modifications, whereas no significant changes could be observed for MMP-2 protein expression between days 21 and 90. Both the 5 and 8 μg/mg gentamicin group showed significantly reduced levels of ß-galactosidase expression and MMP-2 positive stained cells when compared to the PVDF group on day 7, 21 and 90 respectively (5 μg/mg: p < 0.05 each; 8 μg/mg: p < 0.05 each). Though the type I/III collagen ratio increased over time for all mesh modifications significant differences to the PVDF mesh were only detected for the 8 μg/mg group at all 3 time points (p < 0.05 each).</p> <p>Conclusions</p> <p>Our current data indicate that lack of RE-1 is correlated with increased mesh induced MMP-2-gene expression for coated as well as for non-coated mesh materials. Gentamicin coating reduced MMP-2 transcription and protein expression. For the 8 μg/mg group this effect is associated with an increased type I/III collagen ratio. These findings suggest that gentamicin is beneficial for tissue integration after mesh implantation, which possibly is mediated via RE-1.</p

Research of working area development parameters in conditions of deep steep deposit finalizing

Отримано формули розрахунку об’єму запасів корисних копалин в приконтурній та глибинній зоні. Встановлено характер впливу параметрів доробки глибоких крутоспадних родовищ відкритим способом на доцільне положення поточних та проектних контурів кар’єру. Встановлено, що найменший середній коефіцієнт розкриву досягається при мінімальному значенні суми обсягів корисної копалини приконтурної зони лежачого і висячого боків покладу в проектному положенні. Найменший поточний коефіцієнт розкриву досягається при мінімальному значенні суми обсягів корисної копалини приконтурної зони лежачого і висячого боків покладу, а також робочого борту кар'єру в поточному положенні

Oligometastasierung beim kolorektalen Karzinom: moderne Therapiekonzepte

The prognosis of colorectal cancer in UICC stage IV has been improved in the last decades by improvements in interdisciplinary treatment. Treatment strategies for oligometastasized colorectal cancer are developing more and more into an individualized treatment. An overview of the current literature of modern treatment concepts in oligometastasized colorectal cancer UICC stage IV is given. Surgery still has the supreme mandate in resectable colorectal liver metastases, as neoadjuvant and adjuvant treatment strategies to not provide any benefits for these patients. In marginal or non-resectable stages systemic treatment is superior in these patients depending on the prognostic parameters. Also in curative settings local treatment options should be considered as a reasonable additive tool. An interesting treatment approach for isolated liver metastases and non-resectable colorectal cancer is liver transplantation. Irrespective of new developments in treatment strategies for metastasized colorectal cancer, resection of colorectal liver metastases remains the gold standard whenever possible

Video-assisted hepatic abscess debridement

AbstractBackgroundPyogenic liver abscesses are currently treated by either percutaneous computer tomography (CT)-guided drainage or by laparoscopic and a conventional liver resection when conservative treatment fails but may be associated with substantial morbidity and mortality.MethodsA minimally invasive technique involving debridement of right liver abscesses was employed using a minimally invasive video-assisted hepatic abscess debridement (VAHD) after unsuccessful percutaneous CT-guided drainage. Clinical data, complication rates and outcomes of patients were recorded retrospectively.ResultsBetween 2011 and 2014, VAHD was performed on 10 patients at two centres with no observed recurrence of a liver abscess. The median age of the patients was 57 years (range 42–78) with a median pre-operative size of a liver abscess of 78 mm (range 40–115). The median operation time was 47 min (range 23–75), and the median postoperative hospital stay was 9 days (range 7–69). One patient developed a subcutaneous abscess that required further surgery. No patient died, and there were no major complications related to the VAHD.ConclusionsVideo-assisted hepatic abscess debridement is a feasible technique that shows promising results for the treatment of a recurrent right liver abscess