Showing papers by "Danube University Krems published in 2005"

Cleidocranial dysplasia: molecular genetic analysis and phenotypic-based description of a Middle European patient group.

Abstract: Cleidocranial dysplasia (CCD) (OMIM 119600) is a rare dysplasia of osseous and dental tissue. Characteristic features are typical facial and dental appearance plus morphologic anomalies. RUNX2 (OMIM 600211), the responsible gene for CCD, is considered to be a master gene for bone development and bone homeostasis. This study describes the genotype–phenotype correlation based on craniofacial features involving an interdisciplinary approach. Our patient cohort consisted of 31 CCD patients from 20 families; five patients from two families were unavailable for clinical examination. Since CCD mostly affects the craniofacial region, phenotypic characterization of each individual focused on craniofacial and dental aspects. After recording patient medical and family history, the phenotypic data was analyzed using homogeneity analysis (HOMALS), a statistical procedure for data reduction in categorical data analysis. The coding sequence of the RUNX2 gene was analyzed using PCR, direct sequencing, and restriction endonuclease digestion. Eight unpublished and four known heterozygous mutations in a total of 14/20 index patients (70%) were identified. In total, we detected 7 missense mutations, 5 frameshift mutations, and 2 nonsense mutations in 14 index patients (35%, 25%, 10%, respectively). The overall CCD phenotype varied from mild to fullblown expression. Using HOMALS, we were able to discriminate four groups of patients showing significant differences in phenotypic expressivity, thereby simplifying the grouping of our large patient cohort into clear distinguishable entities. Analysis of the mutation patterns revealed that mutational frequency and types of mutations found can be attributed to the gene's structure and function. © 2005 Wiley-Liss, Inc.

On‐line Hemodiafiltration Does Not Induce Inflammatory Response in End‐stage Renal Disease Patients: Results From a Multicenter Cross‐over Study

Abstract: : Background: On-line hemodiafiltration (HDF) represents the supreme blood purification modality for end-stage renal disease (ESRD) patients. Large-volume infusion of on-line prepared substitution fluid may, however, expose patients to inflammatory contaminants. As a result, on-line HDF might aggravate chronic inflammation, which correlates with malnutrition, cardiovascular disease, and mortality among ESRD patients. Methods: In a multicenter cross-over study, 27 ESRD patients were randomly assigned to treatment with on-line HDF and low-flux hemodialysis (HD). After 6 months, patients were crossed to the other treatment modality, and treatment continued for another 6 months. Both on-line HDF and low-flux HD were conducted with polysulfone membranes and ultrapure dialysis fluid. Samples were drawn at the end of each treatment period. Results: Inflammatory parameters were elevated in the study population when compared to healthy controls. Induction of interleukin-1 receptor antagonist (IL-1Ra) and tumor necrosis factor α (TNF-α) was comparable for on-line HDF and low-flux HD, and there was no intradialytic increase in cytokine production. As a result, interleukin-6 (IL-6) plasma levels did not differ significantly between the two treatment modalities. Similarly, no difference between on-line HDF and low-flux HD was observed for C-reactive protein (CRP) and albumin. Markers of endothelial cell activation (soluble intercellular and vascular cell adhesion molecules sICAM-1 and sVCAM-1) as well as the cardiovascular risk marker cardiac troponin T (cTnT) remained elevated compared to healthy subjects, but showed no difference between the two treatment modalities. Conclusions: On-line HDF, as the most effective renal replacement therapy, does not provoke inflammatory response and is both safe and highly biocompatible.

Detection of Fluorescently Labeled Microparticles in Blood

Abstract: Background: A microsphere-based detoxification system is an adsorption system, whereby microadsorbent particles having diameters of 1–20 µm circulate in an extracorporeal filtrate c

Particle leakage in extracorporeal blood purification systems based on microparticle suspensions.

Abstract: Aim: The newly developed ‘Microspheres based Detoxification System’ (MDS) designed for any extracorporeal adsorption therapy uses microparticles as adsorbents characterized by a size of 1–20 µm in diameter which are recirculated in the secondary (filtrate) circuit connected to a hollow fiber filter located in the primary (blood) circuit. In the case of a leakage or rupture in the hollow fiber filter, microspheres can enter patients’ blood circuits and cause embolic episodes in different organs with varying degrees of clinical relevance. Aim of this study was to determine the amount of particles infused to a patient during a long-term treatment under different failure conditions of the filter. Methods: The filters were prepared by cutting single hollow fibers. Fresh-frozen plasma (FFP) and a mixture of glycerol and water were used as a medium together with microparticles potentially used in the MDS.The amounts of particles transferred from the filtrate into the primary circuit were measured. Results: The analysis of particle transfer in the case of a single cut hollow fiber inside the membrane results in particle volumes of up to 26 ml calculated for 10 h. Conclusion: Particle leakage in microparticle suspension based detoxification systems can lead to considerable particle transfer to the patient. Therefore, a particle detection unit which is able to detect critical amounts of particles (

Blind background subtraction in dental panoramic x-ray images: an application approach

Abstract: Dental Panoramic X-ray images are images having complex content, because several layers of tissue, bone, fat, etc. are superimposed. Non-uniform illumination, stemming from the X-ray source, gives extra modulation to the image, which causes spatially varying X-ray photon density. The interaction of the X-ray photons with the density of matter causes spatially coherent varying noise contribution. Many algorithms exist to compensate background effects, by pixel based or global methods. However, if the image is contaminated by a non-negligible amount of noise, that is usually non-Gaussian, the methods cannot approximate the background efficiently. In this paper, a dedicated approach for background subtraction is presented, which operates blind, that means the separation of a set of independent signals from a set of mixed signals, with at least, only little a priori information about the nature of the signals, using the A-Trous multiresolution transform to alleviate this problem. The new method estimates the background bias from a reference scan, which is taken without a patient. The background values are rescaled by a polynomial compensation factor, given by mean square error criteria, thus subtracting the background will not produce additional artifacts in the image. The energy of the background estimate is subtracted from the energy of the mixture. The method is capable to remove spatially varying noise also, allocating an appropriate spatially noise estimate. This approach has been tested on 50 images from a database of panoramic X-ray images, where the results are cross validated by medical experts.

Low-Cost Wireless Transponder System for Industrial and Biomedical Applications

Abstract: Wireless measurement systems utilizing radio frequency identification device (RFID) transponders offer a new and exciting means of measurement and identification suitable for many industrial and biomedical applications. For the majority of these applications, a small, inexpensive radio request sensor system is necessary. To satisfy these requirements, we developed a high integrated RFID transponder system with an on board ultra low-power micro-controller for sensor data read-out and data storage. The sensor system includes hard- and software power saving modes to allow battery powered operation for years. In this paper, an industrial and biomedical sensor/transponder application is described. In addition, the principles, measurements, dataflow and assembly of the sensor/transponder unit are presented and discussed