[Show abstract][Hide abstract] ABSTRACT: The aim of this animal study was to investigate and compare the osseointegration of zirconia and titanium dental implants. 14 one-piece zirconia implants and 7 titanium implants were inserted into the mandibles of 7 minipigs. The zirconia implants were alternately placed submerged and non-submerged. To enable submerged healing, the supraosseous part was removed, using a diamond saw. The titanium implants were all placed submerged. After a healing period of 4 weeks, a histological analysis of the soft and hard tissue and a histomorphometric analysis of the bone-implant contact (BIC) and relative peri-implant bone-volume density (rBVD; relation to bone-volume density of the host bone) was performed. Two zirconia implants were found to be loose. All other implants were available for evaluation. For submerged zirconia and titanium implants, the implant surface showed an intimate connection to the neighbouring bone, with both types achieving a BIC of 53%. For the non-submerged zirconia implants, some crestal epithelial downgrowth could be detected, with a resultant BIC of 48%. Highest rBVD values were found for submerged zirconia (80%), followed by titanium (74%) and non-submerged zirconia (63%). The results suggest that unloaded zirconia and titanium implants osseointegrate comparably, within the healing period studied.
International Journal of Oral and Maxillofacial Surgery 02/2010; 39(6):585-92. · 1.52 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Kallikreins play an important role in tumour microenvironment and as cancer biomarkers in different cancer entities. Previous studies suggested an upregulation of KLK10 and KLK6 in pancreatic ductal adenocarcinoma (PDAC). Therefore, we evaluated the clinicopathological role of these kallikreins and their value as biomarkers in PDAC.Differential expression was validated by DNA-microarrays and immunohistochemistry in normal and malignant pancreatic tissues. Sera concentrations of both kallikreins were evaluated using ELISA. In silico analysis of possible protein interactions and gene silencing of KLK10 in vitro using siRNAs gave further insights in the pathomechanisms.Gene expression analysis and immunohistochemistry demonstrated a strong expression for KLK10 and KLK6 in PDAC. Statistical analysis showed that co-expression of these kallikreins correlated with an R1-resection status (P=0.017) and worse outcome for overall survival (P=0.031). Multivariate analysis proofed that co-expression is an independent prognostic factor for survival (P=0.043). Importantly, KLK10 knockdown in AsPC-1 cells significantly reduced cell migration, whereas computational analysis suggested interaction of KLK6 with angiogenetic factors as an important mechanism.Co-expression of KLK10 and KLK6 plays an unfavourable role in PDAC. Our results suggest that this effect is likely mediated by an interaction with the factors of the extracellular matrix and enhancement of cancer cell motility.
British Journal of Cancer 11/2008; 99(9):1484-92. · 5.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Epigenetic modifications are important events in regulation of gene expression and cancer progression. Methylation of cytosine (C) residues in CpG dinucleotides of promoters is associated with transcriptional silencing. Knowledge about the CpG island methylation status of pancreatic cancer-specific genes could support the development of earlier diagnostic assays and finding new treatment strategies. Several recent patents comprising some of these discoveries have been published. One recent patent describes a method of determining the methylation status of CpG sites in deoxyribonucleic acid (DNA) and correlating it with the presence of tumour cells in pancreas. Another one suggests the usage of the high in Normal 1 (HIN-1) gene as a tool for diagnosis of pancreatic carcinoma. In addition, therapeutic approaches are proposed by two recent patents applying modulators of DNA cytosine-5 methyltransferase such as Decitabine or C-5 methylcytosine. Additionally, a patent introduces a method that couples an early cancer-related and tissue or cell- specific gene marker detection assay, useful as a simultaneous screening test for cancers, including pancreatic cancer. These patents provide new methods in fighting pancreatic cancer by focusing on methylated CpG islands in pancreatic cancer related genes.
Recent patents on DNA & gene sequences. 02/2008; 2(2):97-106.