Publications by authors named "K Halfmeyer"

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.

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B-cell chronic lymphocytic leukemia (B-CLL) is a heterogeneous disease with a highly variable clinical course. Recent studies have shown that CD38 surface expression on the malignant cell clone may serve as a prognostic marker in that CD38(+) patients with B-CLL are characterized by advanced disease stage, lesser responsiveness to chemotherapy, and shorter survival than CD38(-) patients. To further investigate the molecular phenotype of these 2 clinical subgroups, we compared the gene expression profiles of CD38(+) (n = 25) with CD38(-) (n = 45) B-CLL patients using oligonucleotide-based DNA chip microarrays representative of approximately 5600 genes.

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The existence of functional gap junctions between haematopoietic progenitor cells (HPCs) and stromal cells of the haematopoietic microenvironment in the human system is a controversial issue. Primary CD34+ HPCs isolated from leukapheresis products were co-incubated with the human fibroblastoid bone marrow stromal cell line L87/4 in short-term liquid culture. Using the highly sensitive double whole-cell patch-clamp technique, we found that the majority (91%) of CD34+ HPCs are electrically coupled to L87/4 cells.

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We compared the biological effects of the CXC chemokine SDF-1alpha on immunomagnetically purified CD34+ cells isolated from human normal bone marrow (NBM), leukapheresis products (LP) and patients with chronic myeloid leukaemia (CML). LP CD34+ cells showed a significantly stronger migration response to SDF-1alpha (100 ng/ml) than CD34+ cells isolated from the peripheral blood (PB) of CML patients (P < 0.05).

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