DNA methylation of candidate genes in peripheral blood from patients with type 2 diabetes or the metabolic syndrome

Introduction: The prevalence of type 2 diabetes (T2D) and the metabolic syndrome (MetS) is increasing and several studies suggested an involvement of DNA methylation in the development of these metabolic diseases. This study was designed to investigate if differential DNA methylation in blood can function as a biomarker for T2D and/or MetS. Methods: Pyrosequencing analyses were performed for the candidate genes KCNJ11, PPARγ, PDK4, KCNQ1, SCD1, PDX1, FTO and PEG3 in peripheral blood leukocytes (PBLs) from 25 patients diagnosed with only T2D, 9 patients diagnosed with T2D and MetS and 11 control subjects without any metabolic disorders. Results: No significant differences in gene-specific methylation between patients and controls were observed, although a trend towards significance was observed for PEG3. Differential methylation was observed between the groups in 4 out of the 42 single CpG loci located in the promoters regions of the genes FTO, KCNJ11, PPARγ and PDK4. A trend towards a positive correlation was observed for PEG3 methylation with HDL cholesterol levels. Discussion Altered levels of DNA methylation in PBLs of specific loci might serve as a biomarker for T2D or MetS, although further investigation is required

Learning of rigid point-based marker models for tracking with stereo camera systems

Marker-based tracking systems like infrared stereo camera systems are often used to track rigid bodies that are equipped with a certain number of passive or active markers. Getting the knowledge on the geometrical constellations of these markers and their 3D position, to allow easily identification and tracking of various objects, is the basis for most systems. For simple objects with only few markers, getting this knowledge is not problematic. For tracking systems with a lot of cameras, having different views, also more complicated objects with several markers can be learned in simple procedures. However, typical stereo-camera tracking systems consist often in two cameras and if the necessity arises to track more complicated objects than e.g. shutter glasses or typical VR hand devices, where occlusion of markers can not be avoided, a procedure as presented in this paper becomes necessary. This procedure allows successive learning of rigid point-based models, by moving them in the field of view of the cameras, until they are completely measured. Both, the background to the procedures in the different phases and the results from tests with a reference to a real application are described

An augmented reality system for training and assistance to maintenance in the industrial context

Complex Assembly and Maintenance tasks in industrial environments are excellent domains for Augmented Reality (AR) applications. The need for good training and the access to large amounts of documentation are conditions making the use of AR techniques most promising. The basic idea of Augmented Reality is to bring additional information as seamlessly as possible into the view of a user. In this paper an AR system for training and assisting in maintaining equipment in industrial context is presented. The key hardware features of the system are an optical see-through Head Mounted Display, which superimposes the augmentations in the view of the user; the tracking system, which gives the system the poses of user and equipment; and a special stand for the installation of the whole application. Aspects of the usage of an infrared optical tracking system and the calibration procedures needed for good results of the virtual overlays are discussed. Finally a scenario-based concept, which takes users step by step through training or maintenance tasks, is described

Accuracy of needle implantation in brachytherapy using a medical AR system - a phantom study

Brachytherapy is the treatment method of choice for patients with a tumor relapse after a radiation therapy with external beams or tumors in regions with sensitive surrounding organs-at-risk, e. g. prostate tumors. The standard needle implantation procedure in brachytherapy uses pre-operatively acquired image data displayed as slices on a monitor beneath the operation table. Since this information allows only a rough orientation for the surgeon, the position of the needles has to be verified repeatedly during the intervention. Within the project Medarpa a transparent display being the core component of a medical Augmented Reality (AR) system has been developed. There, pre-operatively acquired image data is displayed together with the position of the tracked instrument allowing a navigated implantation of the brachytherapy needles. The surgeon is enabled to see the anatomical information as well as the virtual instrument in front of the operation area. Thus, the Medarpa system serves as 'window into the patient'. This paper deals with the results of first clinical trials of the system. Phantoms have been used for evaluating the achieved accuracy of the needle implantation. This has been done by comparing the output of the system (instrument positions relative to the phantom) with the real positions of the needles measured by means of a verification CT scan