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Peter Hufnagl

Publications and source records attributed to Peter Hufnagl.

10 recordsLinked to original sources
PubMed2006

The diagnostic path, a useful visualisation tool in virtual microscopy.

BACKGROUND: The Virtual Microscopy based on completely digitalised histological slide. Concerning this digitalisation many new features in mircoscopy can be processed by the computer. New applications are possible or old, well known techniques of image analyses can be adapted for routine use. AIMS: A so called diagnostic path observes in the way of a professional sees through a histological virtual slide combined with the text information of the dictation process. This feature can be used for image retrieval, quality assurance or for educational purpose. MATERIALS AND METHODS: The diagnostic path implements a metadata structure of image information. It stores and processes the different images seen by a pathologist during his "slide viewing" and the obtained image sequence ("observation path"). Contemporary, the structural details of the pathology reports were analysed. The results were transferred into an XML structure. Based on this structure, a report editor and a search function were implemented. The report editor compiles the "diagnostic path", which is the connection from the image viewing sequence ("observation path") and the oral report sequence of the findings ("dictation path"). The time set ups of speech and image viewing serve for the link between the two sequences. The search tool uses the obtained diagnostic path. It allows the user to search for particular histological hallmarks in pathology reports and in the corresponding images. RESULTS: The new algorithm was tested on 50 pathology reports and 74 attached histological images. The creation of a new individual diagnostic path is automatically performed during the routine diagnostic process. The test prototype experienced an insignificant prolongation of the diagnosis procedure (oral case description and stated diagnosis by the pathologist) and a fast and reliable retrieval, especially useful for continuous education and quality control of case description and diagnostic work. DISCUSSION: The Digital Virtual Microscope has been designed to handle 1000 images per day in the daily routine work of a pathology institution. It implies the necessity of an automatic mechanism of image meta dating. The non - deterministic correlation between the oral statements (case report) and image information content guides the image meta dating. The presented software opens up new possibilities for a content oriented search in a virtual slide, and can successfully support medical education and diagnostic quality assurance.

Journal Article↗
PubMed2006

Genotyping of the lactase-phlorizin hydrolase -13910 polymorphism by LightCycler PCR and implications for the diagnosis of lactose intolerance.

BACKGROUND: Hypolactasia and lactose intolerance are common conditions worldwide. Hypolactasia seems to be strongly correlated with genotype C/C of the genetic variant C-->T(-13910) upstream of the lactase phlorizin hydrolase (LPH) gene. We developed a rapid genotyping assay for LPH C-->T(-13910) and investigated the relationship of positive lactose breath hydrogen test (LBHT) results suggesting lactose intolerance with LPH C-->T(-13910) genotype. METHODS: Using automated DNA purification on the MagNA Pure LC and real-time PCR on the LightCycler, we examined samples from 220 individuals to estimate genotype frequencies; we then determined LPH C-->T(-13910) genotype in samples from 54 Caucasian patients with a positive LBHT result and symptoms of lactose intolerance. RESULTS: Genotyping of 220 individuals revealed frequencies of 21.4%, 41.8%, and 36.8% for genotypes C/C, C/T, and T/T. Of the patients with positive LBHT results, only 50% had the C/C genotype suggestive of primary adult hypolactasia in our study population. The other patients had various degrees of secondary hypolactasia or symptoms of lactose intolerance. Patients with C/C genotype had a mean (SD) peak H2 increase in the LBHT [108 (58) ppm] that was significantly higher than in patients with the C/T [65 (54) ppm] and T/T [44 (34) ppm] genotypes. CONCLUSIONS: The new real-time PCR assay provides a rapid, labor-saving means for the genotyping of LPH C-->T(-13910). Use of the assay may assist in differentiating patients with primary hypolactasia from those with secondary hypolactasia and lactose intolerance, who may need further clinical examinations to diagnose their underlying primary diseases.

Adolescent↗
PubMed2004

Novel real-time PCR assay for detection of Helicobacter pylori infection and simultaneous clarithromycin susceptibility testing of stool and biopsy specimens.

A biprobe real-time PCR protocol, followed by hybridization melting point analysis, to detect point mutations in the 23S rRNA gene of Helicobacter pylori associated with clarithromycin resistance was established and evaluated in a clinical study. Of 92 patients who underwent endoscopy, 45 were found to be H. pylori infected and invariably were also culture positive. Of the 45 isolates, 11 were shown to be resistant to clarithromycin by E-test. With respect to the detection of H. pylori infection, PCR showed sensitivities of 100% in biopsies and 98% in stool specimens and a specificity of 98% in both biopsy and stool samples. All clarithromycin-sensitive cases were identified as such by PCR in both biopsy and stool samples. Of the cases with a resistant strain, eight were identified as such in stool DNA and nine were identified in biopsy DNA. Failure of PCR to detect the resistant genotype in the biopsy DNA, stool DNA, or both (one case) was associated with mixed populations. In these cases, patients had not been treated for H. pylori infection before, and the sensitive population showed to be present in considerably higher numbers than the resistant population. In five of six cases in which infection with a resistant genotype only was identified by PCR, the patients had received clarithromycin-based eradication therapy in the past. Thus, the assay presented provides a highly accurate noninvasive method to detect H. pylori infection in stool and at the same time allows for culture-independent clarithromycin susceptibility testing.

Adult↗
PubMed2004

Teleconsultation in diagnostic pathology: experience from Iran and Germany with the use of two European telepathology servers.

Eighty pathology cases were sent independently to each of two telepathology servers. Cases were submitted from the Department of Pathology at the University of Kerman in Iran (40 cases) and from the Institute of Pathology in Berlin, Germany (40 cases). The telepathology servers were located in Berlin (the UICC server) and Basel in Switzerland (the iPATH server). A scoring system was developed to quantify the differences between the diagnoses of the referring pathologist and the remote expert. Preparation of the cases, as well as the submission of images, took considerably longer from Kerman than from Berlin; this was independent of the server system. The Kerman delay was mainly associated with a slower transmission rate and longer image preparation. The diagnostic gap between referrers' and experts' diagnoses was greater with the iPATH system, but not significantly so. The experts' response time was considerably shorter for the iPATH system. The results showed that telepathology is feasible for requesting pathologists working in a developing country or in an industrialized country. The key factor in the quality of the service is the work of the experts: they should be selected according to their diagnostic expertise, and their commitment to the provision of telepathology services is critical.

Germany↗
PubMed2003

Antiinflammatory activity of astragaloside IV is mediated by inhibition of NF-kappaB activation and adhesion molecule expression.

The regulated expression of adhesion molecules on the surface of endothelial cells is a key process in the pathogenesis of inflammation. The saponin astragaloside IV (AS-IV), a 3-O-beta-D-xylopyranosyl-6-O-beta-D-glucopyranosylcycloastragenol purified from the Chinese medical herb Astragalus membranaceus (Fisch) Bge. has been shown to have anti-inflammatory effects in vivo. In this study we have investigated the effect of AS-IV on cytokine-and LPS-stimulated expression of adhesion molecules in and leukocyte adhesion to endothelial cells. We have demonstrated that AS-IV significantly reduced the adhesion promoting activity of LPS-stimulated HUVECs for polymorph-nuclear leukocytes (PMNs) and the monocytic cell line THP-1. Furthermore, by using specific cell ELISAs we could show that AS-IV decreased the LPS-induced expression of E-selectin and VCAM-1 on the surface of HUVECs in a dose and time dependent manner, whereas the expression of ICAM-1 was not affected by AS-IV. AS-IV also inhibits TNFalpha-induced VCAM-1 expression. The saponin octyl-D-glucopyranoside had no effect on the LPS-induced expression of E-selectin and VCAM-1 excluding an unspecific detergent-like effect of AS-IV. Moreover, AS-IV significantly inhibited LPS- and TNFalpha-induced specific mRNA levels for E-selectin and VCAM-1. Finally, we could show that AS-IV completely abolished LPS- and TNFalpha-induced nuclear translocation of NF-kappaB and NF-kappaB DNA binding activity in endothelial cells. We conclude that the ability of AS-IV to inhibit the NF-kappaB pathway might be one under-lying mechanism contributing to its anti-inflammatory potential in vivo.

Anti-Inflammatory Agents↗
PubMed2002

Direct binding of Nur77/NAK-1 to the plasminogen activator inhibitor 1 (PAI-1) promoter regulates TNF alpha -induced PAI-1 expression.

Plasminogen activator inhibitor 1 (PAI-1) is the main fibrinolysis inhibitor, and high plasma levels are associated with an increased risk for vascular diseases. Inflammatory cytokines regulate PAI-1 through a hitherto unclear mechanism. Using reporter gene analysis, we could identify a region in the PAI-1 promoter that contributes to basal expression as well as to tumor necrosis factor alpha (TNFalpha) induction of PAI-1 in endothelial cells. Using this region as bait in a genetic screen, we could identify Nur77 (NAK-1, TR3, NR4A1) as an inducible DNA-binding protein that binds specifically to the PAI-1 promoter. Nur77 drives transcription of PAI-1 through direct binding to an NGFI-B responsive element (NBRE), indicating monomeric binding and a ligand-independent mechanism. Nur77, itself, is transcriptionally up-regulated by TNFalpha. High expression levels of Nur77 and its colocalization with PAI-1 in atherosclerotic tissues indicate that the described mechanism for PAI-1 regulation may also be operative in vivo.

Arteriosclerosis↗
PubMed2002

Rapid diagnosis of enterovirus infections by real-time PCR on the LightCycler using the TaqMan format.

A 2 h single-tube, reverse-transcription(RT)-PCR/hybridization assay using the TaqMan format for rapid diagnostic screening of enterovirus (EV) infections was optimized for the real-time LightCycler (LC) technology. For low EV load clinical samples an additional 30 min reamplification step using a novel primer-mix/probe design resulted in a 100% concordance with AMPLICOR EV PCR Test and in-house RT-PCR. Combined with maximum specificity, the sensitivity of LC-PCR was 10- to 100-fold higher compared to AMPLICOR EV Test.

Enterovirus↗
PubMed2002

Plasminogen activator inhibitor 1: physiological and pathophysiological roles.

Plasminogen activator inhibitor 1 (PAI-1) inhibits plasminogen activators (u-PA and t-PA) by forming stable complexes endocytosed via a low-density lipoprotein receptor superfamily member-dependent mechanism. PAI-1 circulates actively in plasma and latently in platelets but is also secreted and deposited into the matrix by several cells, where it participates in tissue repair processes.

Hemostatic Disorders↗
PubMedDate not supplied

Expression, proliferation activity and clinical significance of cathepsin B and cathepsin L in operated lung cancer.

AIMS: To immunohistochemically investigate the expression of cathepsin B and cathepsin L in various lung cancer cell types in association with the patients' prognosis. MATERIALS AND METHODS: Histological slides obtained from formalin-fixed, paraffin-embedded tissue of 120 potentially curative resected lung cancer specimens (20 cases of each of the following cell types: squamous cell, adeno, large cell anaplastic, small cell anaplastic, intrapulmonary metastases, mesotheliomas) were quantitatively immunohistochemically analysed with an automated image analysing system and correlated with the patients' prognosis and the tumour proliferation rate measured by the expression of Ki-67. RESULTS: The expression of cathepsin B was most frequently present in large cell anaplastic carcinomas and missing in small cell carcinomas. That of cathepsin L was less frequently seen, and mainly expressed in macrophages and adenocarcinoma tumour cells. The structural heterogeneity of cathepsin B expression measured by syntactic structure analysis was greater than that of cathepsin L. The expression of cathepsin B is of prognostic significance in non-small cell lung cancer, and ranges directly after the pN and pT stages in multivariate statistical analysis. CONCLUSION: In concordance with the literature, the expression of cathepsin B in non-small cell lung cancer should be considered as a significant prognostic parameter in contrast to that of cathepsin L, which is not related to the patients' outcome at a statistically significant level.

Carcinoma, Non-Small-Cell Lung↗