Class 1 integrons in ciprofloxacin-resistant Escherichia coli strains from two Dutch hospitals.

A significant increase in the isolation frequency of ciprofloxacin-resistant Escherichia coli was observed in the haematology departments of two university hospitals in The Netherlands. Amplified fragment length polymorphism analysis revealed that this increase was not caused by the emergence of unique ciprofloxacin-resistant clones. Determination of the presence of class 1 integrons indicated that 81% of the ciprofloxacin-resistant isolates contained an intI1 gene, compared with 11% of the ciprofloxacin-susceptible isolates (p<0.0001). The quinolone resistance gene qnrA was not present in any of the integrons characterised and could not be detected using dot-blot hybridisation of total DNA. In addition, conjugation experiments showed that ciprofloxacin resistance was not co-transferred with class 1 integrons. Ciprofloxacin-resistant isolates harboured mutations in the gyrA gene, which are known to encode ciprofloxacin resistance. In conclusion, an association was observed between ciprofloxacin resistance and the presence of class 1 integrons, which could not be explained by the currently known genetic determinants of quinolone resistance.

High-dose therapy followed by bone marrow transplantation for relapsed follicular non-Hodgkin's lymphoma. Dutch HOVON Group.

PURPOSE: To analyze whether, in addition to survival, and disease-free survival progression-free interval after transplantation would be longer than the last progression-free interval before transplantation, supporting the argument that high-dose therapy may change the biologic behavior of the disease. PATIENTS AND METHODS: Patients with a poor-risk relapsed follicular NHL were treated with three cycles of doxorubicin 50 mg/m2 and teniposide 60 mg/m2, followed by etoposide 350 mg/m2, cyclophosphamide 60 mg/kg, and TBI and unpurged BMT. RESULTS: Twelve patients were entered in the study. Ten patients fulfilled the criteria for response and underwent transplantation, two of them with an allograft. Nine of ten patients with transplants achieved a complete remission after BMT. One patient died on day 41 due to veno-occlusive disease. The nine patients with transplants who were evaluable for follow-up had a conversion of remission or response duration after transplantation, their progression-free interval after BMT being superior to the last one before BMT with a median of 1044 + days. Overall survival and disease-free survival in the transplant patients after a median follow-up of 1160 days from BMT is 90%. CONCLUSION: High dose chemotherapy followed by stem cell rescue may change the clinical course in follicular non-Hodgkin's lymphoma patients.

Subunit IV of human cytochrome c oxidase, polymorphism and a putative isoform.

As part of our study of isoenzyme forms of human cytochrome c oxidase, we purified subunit IV from human heart and skeletal muscle with reversed-phase HPLC and determined the N-terminal amino acid sequences and the electrophoretic mobility. The N-terminus of human heart subunit IV proved to be ragged with 30% of the protein lacking the first three residues. Also a Tyr/Phe polymorphism was observed at residue 16. No differences in N-terminal sequence and electrophoretic mobility were observed between subunit IV of cytochrome c oxidase from human heart and skeletal muscle. Therefore, our results suggest that identical subunits IV are present in cytochrome c oxidase from human heart and skeletal muscle. A putative isoform of subunit IV with a blocked N-terminus was purified from human heart cytochrome c oxidase, which proved to have a different retention time on a reversed-phase column and also a slightly higher electrophoretic mobility on an SDS-polyacrylamide gel compared to the native subunit IV. We could not demonstrate the existence of isoforms of subunit IV in human skeletal muscle.