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Frank Klebl

Publications and source records attributed to Frank Klebl.

5 recordsLinked to original sources
PubMed2006

Multiparameter immunofluorescence on paraffin-embedded tissue sections.

Immunohistochemical techniques have gained increasing importance in diagnostics and research. While formalin-fixed, paraffin-embedded human tissue retains excellent morphology, the detection of antigens by immunofluorescence in its sections and especially the demonstration of multiple simultaneous antibodies have limitations. Double immunofluorescence labeling of routinely processed paraffin sections has been described previously. The signal intensity observed after triple labeling has been reported to be significantly inferior to that obtained by application of double fluorochromes. The authors show multicolor labeling of three and four primary antibodies in routinely processed paraffin-embedded tissue sections using a standardized immunofluorescence technique. In addition, procedures to reduce background staining and to avoid nonspecific double staining are described.

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PubMed2005

The effect of chromoendoscopy on the diagnostic improvement of gastric ulcers by endoscopists with different levels of experience.

BACKGROUND: In recent years chromoendoscopy has become popular as a diagnostic enhancement tool in endoscopy. Using the macroscopic description of gastric ulcers, experienced endoscopists may be able to differentiate malignant and benign lesions. The aim of our study was to determine whether indigo carmine staining improves the ulcer differentiation by experienced and inexperienced endoscopists. METHODS: 50 patients were enrolled, 7 with malignant gastric ulcers and 43 with benign gastric ulcers. Gastroscopy was initially videotaped native, then on a second tape after staining with 0.2% indigo carmine. Later on biopsies were taken for histology. Subsequently the tapes were randomly evaluated by three experienced (>2000 gastroscopies; group A) and by three inexperienced (<100 gastroscopies; group B) investigators blinded from any personal data of the patients. The investigators had to classify the ulcers, using published criteria, native as well as stained. The results were compared within each group and with the histology. RESULTS: The endoscopic native diagnosis showed a sensitivity of 66.3%, a specificity of 86.3%, a positive predictive value of 48.1% and a negative predictive value of 94% for group A, respectively 66%, 62.5%, 22.7% and 92% for group B. After staining, the values of these parameters were reduced insignificantly to a sensitivity of 60.2%, a specificity of 78.5%, a positive predictive value of 36.1% and a negative predictive value of 92.8% for group A. Group B, on account of one investigator who demonstrated excellent skills, showed a significant better sensitivity (79.9%) and a slight improvement of the positive and negative predictive values to 25.7% respectively 94.8%, whereas the specificity very slightly decreased to 61.3%. The diagnostic accuracy before and after staining was 83.6%, respectively 76.5%, in group A and 63.2%, respectively 63.9% in group B. The correlation with the histology, determined by Cohen's kappa coefficient (median value), decreased from 0.46 for the native to 0.30 for the chromoendoscopic diagnosis in group A and remained unchanged (0.17) in group B. CONCLUSION: We concluded that chromoendoscopy does not improve the classification of gastric ulcers with respect to malignant or benign origin. The role of endoscopic experience could only be proved in the native macroscopic diagnosis of the investigators. After staining, with the exception of one investigator, experienced as well as inexperienced endoscopists lost their diagnostic accuracy.

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PubMed2004

Risk factors for mortality in severe upper gastrointestinal bleeding.

BACKGROUND AND AIMS: Factors related to mortality after upper gastrointestinal (GI) bleeding may differ in importance in high- and low-risk populations. This retrospective study was undertaken to define risk factors of mortality in patients needing endoscopy for upper gastrointestinal bleeding at a tertiary care centre. PATIENTS/METHODS: Three hundred and sixty-two patients with upper gastrointestinal bleeding were identified from endoscopy charts. Patients' characteristics, bleeding parameters, clinical presentation, pre-existing medication and laboratory data were retrieved from hospital charts and patients who survived and those who died in hospital were compared. RESULTS/FINDINGS: The mean Rockall score was 6.6+/-1.3 with 92.5% of patients belonging to a Rockall high-risk group. In hospital, mortality was 26.5%, with 6.4% of patients dying as a direct consequence of bleeding. Variceal bleeding was associated with a high risk of recurrent bleeding and death. Renal disease, liver disease, coagulopathy and immunosuppression were more frequently found in non-survivors than in survivors. Accordingly, serological tests of renal or liver function and coagulation were more disturbed in non-survivors. On average, heart rate was higher, and blood pressure and haemoglobin levels lower in non-survivors. Heparin, glucocorticoids, and anti-ulcer drugs were more frequently used in patients dying in hospital. By logistic regression analysis, in-patient status at the time of bleeding, renal disease and coagulopathy, as well as glucocorticoid use, were risk factors for hospital mortality. INTERPRETATION/CONCLUSION: In tertiary care, a high mortality rate is observed in upper GI bleeding. Teams involved in treating such patients should be aware of the setting in which treatment is performed and its related risk factors.

Adult↗
PubMed2003

Histopathological parameters as predictors for the course of Crohn's disease.

BACKGROUND: Recent classification systems discriminate penetrating Crohn's disease (CD) from stricturing and non-stricturing/non-penetrating CD. As yet, no easily detectable marker is known that can predict the course of CD. Individual, clinical course-specific new treatment schemes would be highly desirable for different potentially divergent pathophysiological pathways (e.g., fistula vs stenosis). METHODS: Intestinal tissue biopsies from 63 CD patients with a disease follow-up of up to 7 years were studied retrospectively. In biopsy specimens, 34 histopathological features present prior to the onset of (a) strictures or (b) fistulas were evaluated and compared with biopsies from patients with non-stricturing/non-penetrating disease. RESULTS: Five histomorphological parameters demonstrated significant associations to different disease courses when applying univariate analysis. In a multivariate logistic regression model (1) severe lymphocytic infiltration of the lamina propria, (2) presence of crypt atrophy, and (3) absence of lymphocytic infiltration of the epithelium are the best variables to predict an uncomplicated disease course (Nagelkerke R2=0.329; P=0.001). The combination of these parameters has a sensitivity of 67% and a specificity of 83% to predict non-stricturing/non-penetrating disease (positive predictive value=0.75). CONCLUSION: Histopathological parameters may help to predict complications of CD prior to their onset. The results of this study have to be confirmed prospectively.

Adult↗