Explaining variability in ciclosporin exposure in adult kidney transplant recipients

International audienc

Automatic Tumor-Stroma Separation in Fluorescence TMAs Enables the Quantitative High-Throughput Analysis of Multiple Cancer Biomarkers

The upcoming quantification and automation in biomarker based histological tumor evaluation will require computational methods capable of automatically identifying tumor areas and differentiating them from the stroma. As no single generally applicable tumor biomarker is available, pathology routinely uses morphological criteria as a spatial reference system. We here present and evaluate a method capable of performing the classification in immunofluorescence histological slides solely using a DAPI background stain. Due to the restriction to a single color channel this is inherently challenging. We formed cell graphs based on the topological distribution of the tissue cell nuclei and extracted the corresponding graph features. By using topological, morphological and intensity based features we could systematically quantify and compare the discrimination capability individual features contribute to the overall algorithm. We here show that when classifying fluorescence tissue slides in the DAPI channel, morphological and intensity based features clearly outpace topological ones which have been used exclusively in related previous approaches. We assembled the 15 best features to train a support vector machine based on Keratin stained tumor areas. On a test set of TMAs with 210 cores of triple negative breast cancers our classifier was able to distinguish between tumor and stroma tissue with a total overall accuracy of 88%. Our method yields first results on the discrimination capability of features groups which is essential for an automated tumor diagnostics. Also, it provides an objective spatial reference system for the multiplex analysis of biomarkers in fluorescence immunohistochemistry

Selective cefuroxime prophylaxis following colorectal surgery based on intra-operative dipslide culture

The concept of a very limited effective period for prophylactic antibiotic action was challenged in a prospective, controlled and randomized study featuring a simplified method for assessing the degree of contamination in the operative field during colorectal surgery. The 226 patients were given 1 g metronidazole IV on induction of anaesthesia and 12 h postoperatively. Following standardized saline irrigation of the abdominal cavity, a uriculture dipslide was dipped in the residual fluid just before abdominal closure. The dipslide was incubated for 18 h, and colony counts of coliforms and Staphylococcus aureus were made. The number of colony-forming units (CFU) was classified as 0, 1-4 or greater than or equal to 5 (n = 123, 33 and 70). The patients with CFU greater than or equal to 5 were randomized to receive cefuroxime (1.5 g IV/8 h for 2 days) or no more antibiotics. In the patients given only metronidazole, the incidence of postoperative infections rose with the colony counts (5.7, 9.1 and 41.2 per cent with CFU 0, 1-4 and greater than or equal to 5). Addition of cefuroxime reduced the 41.2 per cent infection rate to 8.3 per cent (P = 0.003). The method thus identified a high-risk group in which a short postoperative course of cefuroxime significantly lowered the rate of sepsis