Donor variables correlated with CD34+ cell yield only weakly, so no particular clinical characteristic can be used to exclude an individual as a PBPC donor if he or she is otherwise suitable for the apheresis procedure.
Summary. Karyotypic studies of bone marrow were conducted in 79 previously untreated patients with multiple myeloma who received a standard programme of chemotherapy. An abnormal karyotype was observed in 46% of patients, virtually all showing multiple abnormalities consistent with a long period of preclinical clonal evolution. Patients with an abnormal pattern showed various aberrations with hyperdiploidy in 64%, pseudodiploidy in 5% and hypodiploidy in 31%. The number of chromosomes affected ranged from two to 19 (median 10), with at least one trisomy in 83%, one monosomy in 75%, and one translocation in 42% of patients. Lymphoma-like karyotypes were present in 17% of patients with an abnormality but were not associated with atypical clinical features, such as an extramedullary mass, leukaemia, or increased serum lactate dehydrogenase. Monosomy or deletion of chromosome 13 was present in 47% of patients with an abnormal pattern, who lived for a shorter duration (median 10 months) than patients with other abnormalities (median 34 months) or with diploidy (median 35 months). The cause of the short survival of patients with monosomy or deletion of chromosome 13 was not clear, but further studies on the relationship with specific oncogenes are indicated.
The epithelial cells that form a barrier lining the lung airway are key regulators of neutrophil trafficking into the airway lumen in a variety of lung inflammatory diseases. Although the lipid mediator leukotriene B4 (LTB4) is known to be a principal chemoattractant for recruiting neutrophils to inflamed sites across the airway epithelium, the precise signaling mechanism involved remains largely unknown. In the present study, therefore, we investigated the signaling pathway through which LTB4 induces transepithelial migration of neutrophils. We found that LTB4 induces concentration-dependent transmigration of DMSO-differentiated HL-60 neutrophils and human polymorphonuclear neutrophils across A549 human lung epithelium. This effect was mediated via specific LTB4 receptors and was inhibited by pretreating the cells with N-acetylcysteine (NAC), an oxygen free radical scavenger, with diphenylene iodonium (DPI), an inhibitor of NADPH oxidase-like flavoproteins, or with PD98059, an extracellular signal-regulated kinase (ERK) inhibitor. Consistent with those findings, LTB4-induced ERK phosphorylation was completely blocked by pretreating cells with NAC or DPI. Taken together, our observations suggest LTB4 signaling to transepithelial migration is mediated via generation of reactive oxygen species, which leads to downstream activation of ERK. The physiological relevance of this signaling pathway was demonstrated in BALB/c mice, in which intratracheal instillation of LTB4 led to acute recruitment of neutrophils into the airway across the lung epithelium. Notably, the response to LTB4 was blocked by NAC, DPI, PD98059, or CP105696, a specific LTB4 receptor antagonist.
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