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W U Knauf

Publications and source records attributed to W U Knauf.

25 records · Page 2Linked to original sources
PubMed1993

Detection of circulating monoclonal lymphocytes in multiple myeloma patients by analysis of gene rearrangements: correlation with progressive disease.

Multiple myeloma is characterized by the proliferation of a monoclonal plasma cell population that essentially spreads in the bone marrow. However, immunological data and studies on clonal gene rearrangements have provided evidence for circulating malignant B-lymphocytes. Herein, we report on the detection and clinical significance of monoclonal lymphocytes in the peripheral blood of multiple myeloma patients. Applying the analysis of immunoglobulin gene rearrangements, clonal circulating lymphocytes were found in 8 out of 37 patients. In three of these eight patients, DNA from the bone marrow could be examined as well, and the same gene rearrangement as in peripheral blood was detected. This observation indicates that the monoclonal lymphocytes in the peripheral blood are part of the malignant plasma cell clone in the bone marrow. There was a strong correlation between progressive stage III disease and the detection of circulating tumour cells, whereas neither in stable stage III nor stage I disease could clonal gene rearrangements be detected. Our findings indicate the high incidence of monoclonal lymphocytes in the peripheral blood from patients with progressive multiple myeloma. This may be of importance with respect to cell harvesting strategies for autologous peripheral stem cell transplantation in multiple myeloma.

Aged↗
PubMed1992

A phase I trial of interferon alpha-2b with folinic acid and 5-fluorouracil administered by 4-hour infusion in metastatic colorectal carcinoma.

Preclinical data suggest that both folinic acid and interferon may enhance the efficacy of 5-fluorouracil (5-FU) in colorectal carcinoma. We therefore initiated a phase I trial evaluating the doses, safety, and pharmacokinetics of the combination of recombinant interferon (IFN) alpha-2b with folinic acid (FA) and 5-FU. Seventeen patients with colorectal cancer who failed local chemotherapy received 5-FU as a 4-hour infusion, preceded by a bolus of FA and IFN. The 5-FU dose was escalated over the range of 400 to 650 mg/m2/d for a period of 7 days. Folinic acid was administered as a bolus in a fixed dose of 200 mg/m2/d and IFN as 5 million U/d subcutaneously on days 1 to 7. A total of 89 courses of therapy were completed for the 17 patients, of which there were 10 paired courses with a combination of 5-FU and IFN or 5-FU alone, being performed to analyze the pharmacokinetics and modulation of 5-FU by IFN. The maximum tolerated dose of 5-FU using this combination and a 4-hour schedule was 600 mg/m2/d for 7 days. The dose-limiting toxicity of this regimen was diarrhea. Mucositis and myelosuppression was not a marked problem at dose levels of 400 and 500 mg/m2/d for 7 days. However, at a dose level of 600 to 650 mg/m2/d for 7 days, grade 3 and 4 (WHO) leukopenia occurred in 50% and mucositis occurred in 33%. At a given dose of 5 million U, IFN did not significantly influence 5-FU serum levels. Mean steady-state serum levels of 5-FU at 500 mg/m2 given as a 4-hour infusion were 16.55 +/- 9.34 mumol/L and 18.23 +/- 12.77 mumol/L with and without IFN, respectively. Mean area under the curve (mumol/L x min) was 4,008 +/- 2,133 and 5,114 +/- 2,567 with and without interferon, respectively. Objective responses were seen in one of 17 of these heavily pretreated patients and stable disease was seen in seven of 17 patients. The recommended dose of 5-FU for use of phase II studies is 500 mg/m2/d for 7 days. We conclude that the toxicity of 5-FU plus FA with and without IFN alpha-2b can be reduced by using a 4-hour infusion instead of a bolus.

Adult↗
PubMed1991

Detection of bone marrow infiltration by non-Hodgkin's lymphoma--comparison of histological findings, analysis of gene rearrangements, and examination by magnetic resonance imaging.

The histological examination of bone marrow specimens is one of the standard procedures in staging non-Hodgkin's lymphoma. To investigate the validity of a conventional unilateral iliac crest biopsy, we performed a prospective study comparing histological findings with analysis of gene rearrangements in bone marrow samples and magnetic resonance imaging of bone marrow. Twenty-seven consecutive patients with non-Hodgkin's lymphoma (ten with high grade, seventeen with low grade) were studied. In twelve patients, histological examination revealed bone marrow infiltration. Results of histology and magnetic resonance imaging were discordant in three of the twenty-seven patients. With magnetic resonance imaging, suspected infiltration was found in two patients without histological evidence for bone marrow involvement in the disease. In one patient, an infiltration was described by histology but MRI revealed no pathological findings. In this case, DNA analysis confirmed bone marrow infiltration by detection of a clonal rearrangement of the immunoglobulin heavy chain gene. Analysis of gene rearrangements was performed in ten patients. As examined by histology, five of them had bone marrow involvement in the disease and five had not. In all these cases, analysis of gene rearrangements confirmed the histological findings. Our data show that, despite the small volume of bone marrow specimens, the sensitivity of an iliac crest biopsy seems to be high in staging non-Hodgkin's lymphoma.

Adult↗
PubMed1988

Clinical response to deoxycoformycin in chronic lymphoid neoplasms and biochemical changes in circulating malignant cells in vivo.

Deoxycoformycin (DCF), an adenosine deaminase (ADA) inhibitor, has been shown to be active in lymphoid neoplasms. The mechanism of cytotoxicity might involve accumulation of deoxyadenosine triphosphate (dATP), depletion of the nicotinamide adenine dinucleotide (NAD) and ATP pool, induction of double-stranded DNA strand breaks, or inhibition of S-adenosyl homocysteine hydrolase (SAH-hydrolase). We have investigated the biochemical changes in the circulating malignant cells of patients with chronic leukemia/lymphoma who were treated with DCF (4 mg/m2 weekly). Blood samples were taken from 17 patients with 60% or more circulating leukemic cells before, 4, 24, and 48 hours and five days after the first administration of DCF. Leukemic cells were separated and studied for changes in ADA, dATP, ATP, NAD, and SAH-hydrolase levels and DNA strand breaks and the data analyzed according to clinical response. Inhibition of ADA activity was found in all except one patient at 4 to 24 hours after the first administration of DCF. dATP started to accumulate at four hours, reached a maximum level between 24 and 48 hours, and returned to base values on the fifth day. Intracellular ATP and NAD levels were transiently reduced in some of the patients. However, no correlation between these changes and a clinical response could be found. DNA strand breaks could be studied in 13 patients. A significant increase in DNA breaks at 24 to 48 hours was found in six of the seven responders but only in one of the six nonresponders. At 24 hours, SAH-hydrolase levels were reduced in all seven responders studied, but only in two of the seven nonresponders. The difference in inhibition of SAH-hydrolase was statistically significant (P = .0023). These results suggest that DNA strand breaks and inhibition of SAH-hydrolase correlate with clinical response.

Adenosine Deaminase Inhibitors↗
PubMedDate not supplied

Polymorphism of the human Ha-ras oncogene locus in chronic lymphocytic and chronic myelogenous leukemia.

DNA from white blood cells from healthy controls demonstrates a restriction fragment length polymorphism (RFLP) of the Ha-ras oncogene locus after cleavage with the restriction enzymes BamH I or MspI plus HpaII, representing frequent and rare alleles. We have studied the RFLP of 15 patients with B-cell chronic lymphocytic (CLL) and of 16 patients with chronic myelogenous leukemia (CML). As in healthy controls the RFLP in the leukemic cells indicates the occurrence of frequent and rare Ha-ras alleles. But rare alleles are not more frequent in the patients than in the healthy control group. The frequency of rare Ha-ras alleles also does not differ between chronic lymphocytic and chronic myelogenous leukemia. While rare alleles of this oncogene locus occur in CML and CLL as frequently as in healthy controls, they do not reflect an inherent increased risk for chronic leukemia in man.

Alleles↗