Biomedical subjects

A Führer

Publications and source records attributed to A Führer.

4 recordsLinked to original sources

PubMed2006

Gene expression signatures separate B-cell chronic lymphocytic leukaemia prognostic subgroups defined by ZAP-70 and CD38 expression status.

B-cell chronic lymphocytic leukaemia (B-CLL) is a heterogenous disease with a highly variable clinical course and analysis of zeta-associated protein 70 (ZAP-70) and CD38 expression on B-CLL cells allowed for identification of patients with good (ZAP-70-CD38-) and poor (ZAP-70+CD38+) prognosis. DNA microarray technology was employed to compare eight ZAP-70+CD38+ with eight ZAP-70-CD38- B-CLL cases. The expression of 358 genes differed significantly between the two subgroups, including genes involved in B-cell receptor signaling, angiogenesis and lymphomagenesis. Three of these genes, that is, immune receptor translocation-associated protein 4 (IRTA4)/Fc receptor homologue 2 (FcRH2), angiopoietin 2 (ANGPT2) and Pim2 were selected for further validating studies in a cohort of 94 B-CLL patients. IRTA4/FcRH2 expression as detected by flow cytometry was significantly lower in the poor prognosis subgroup as compared to ZAP-70-CD38- B-CLL cells. In healthy individuals, IRTA4/FcRH2 protein expression was associated with a CD19+CD27+ memory cell phenotype. ANGPT2 plasma concentrations were twofold higher in the poor prognosis subgroup (P<0.05). Pim2 was significantly overexpressed in poor prognosis cases and Binet stage C. Disease progression may be related to proangiogenic processes and strong Pim2 expression.

ADP-ribosyl Cyclase 1↗

PubMed2003

ZAP-70 expression is a prognostic factor in chronic lymphocytic leukemia.

B-cell chronic lymphocytic leukemia (B-CLL) is a heterogenous disease with a highly variable clinical course. Recent studies have shown that expression of the protein tyrosine kinase ZAP-70 may serve as a prognostic marker in B-CLL. Employing a semiquantitative RT-PCR assay, we examined purified leukemia B cells of 39 CLL patients for the expression of ZAP-70 mRNA transcripts. Significant ZAP-70 mRNA levels exceeding those found in control samples with 5% T cells were detected in 36% of the CLL cases. Patients in the ZAP-70 positive cohort were characterized by an unfavorable clinical course with a significantly shorter progression-free survival as compared to the ZAP-70-negative patients (64%). These results were confirmed by flow-cytometric analysis of the ZAP-70 protein, and expanded to a larger patient cohort (n=67). A combined statistical analysis of 79 patients showed that the two patient subgroups also differed with regard to overall survival and a panel of known clinical prognostic factors including LDH, thymidine kinase serum levels and expression of the CD38 surface antigen by the leukemic cell clone. The level of ZAP-70 expression did not change over time in the majority of patients where sequential samples were available for analysis.

ADP-ribosyl Cyclase↗

PubMed2002

HepatoConsult: a knowledge-based second opinion and documentation system.

HepatoConsult is a publicly available knowledge-based second opinion and documentation system aiding in the diagnosis of liver diseases. The positive results of a prospective diagnostic evaluation study encouraged its use in clinical routine, although the available hardware infrastructure was not optimal. The comments of the physicians who used the system confirmed the results of the study and showed that the time for data entering is acceptable and the implicit standardization of terminology and documentation is welcome. Suggestions for improvement included the interface to enter data more easily, the scope to be usable for more patients and the additional capability to generate medical reports from the data.

Artificial Intelligence↗

PubMed1999

[The evaluation of HepatoConsult, a hepatological expert system--the initial results and trends].

BACKGROUND AND OBJECTIVE: HepatoConsult (HC) is a medical expert system, based on the expert system building block D3, designed to aid in the diagnosis of liver and biliary tract disease. It was the aim of this study to evaluate its diagnostic competence in clinical cases prospectively. PATIENTS AND METHODS: The diagnostic accuracy of HC was tested prospectively in 106 consecutive patients with the main diagnosis of liver disease. 57 were ambulant, 49 were in-patients. The data were obtained and stored at defined phases of the diagnosis. The diagnoses put forward by HC were compared with the final clinical diagnosis and, on the basis of the data, checked for plausibility by four experienced physicians. RESULTS: After history taking and physical examination HC put forward the main diagnosis, as established by the doctors in charge, in 60% of patients. After addition of the results of basic laboratory tests and sonography, HC provided the correct diagnosis in 85% and, after inclusion of all the findings, in 93%. In almost all cases HC put forward diagnoses that were, on the basis of the supplied data, considered correct by the four physicians experienced in liver disease. In 56% of cases HC provided more differentiated diagnoses or items in the differential diagnosis than the attending doctors. In the opinion of the four assessors HC had not put forward any seriously wrong diagnoses. CONCLUSION: HC can be useful in solving diagnostic problems and thus in ensuring the quality of medical diagnoses.

Diagnosis, Computer-Assisted↗