Effects of tumour necrosis factor alpha on bone marrow aspirates of patients with acute myelogenous leukemia determined by flow-cytometric cell-cycle analysis

Effects of tumour necrosis factor-alpha on BrdU incorporation in cultured human enterocytes

Bromodeoxyuridine incorporation is a useful method for studying the pattern of DNA synthesis in proliferating cells. The distribution pattern of incorporated BrdU in villus enterocytes of duodenal explants was analysed after exposure to TNFα in organ culture. TNFα caused a consistent, low level uptake of BrdU in the portion of the nucleus close to the nuclear membrane, this pattern was absent from the control cultures. As these epithelial cells are terminally arrested in G₀, the BrdU incorporation was thought not to be due to S phase DNA synthesis, but rather a response to the cytotoxic influence of TNFα. Microtitre plate proliferation assays of cell density and DNA synthesis were devised to study the effects of TNFα on confluent monolayers of the human foetal jejunal cell line I407 and the mouse fibrosarcoma cell line L929. Both cell lines showed a similar response to TNFα. Exposure to TNFα alone did not reduce cell numbers but did cause a significant increase in DNA synthesis (p < 0.05). When cycloheximtde was added in tandem with TNFα there was a significant reduction in cell number (p < 0.001) and level of DNA synthesis (p < 0.01) indicative of cell death. The DNA of cells exposed to TNFα and cycloheximide was fragmented when viewed on an electrophoresis gel. The results show that BrdU incorporation might be a good indicator of damage to the DNA of cells after cytotoxic insult. TNFα may be responsible for villus enterocyte damage in enteropathies such as coeliac disease and GVHR of the small bowel.

Bromodeoxyuridine: a diagnostic tool in biology and medicine, Part III. Proliferation in normal, injured and diseased tissue, growth factors, differentiation, DNA replication sites and in situ hybridization

This paper is a continuation of parts I (history, methods and cell kinetics) and II (clinical applications and carcinogenesis) published previously (Dolbeare, 1995 Histochem. J. 27, 339, 923). Incorporation of bromodeoxyuridine (BrdUrd) into DNA is used to measure proliferation in normal, diseased and injured tissue and to follow the effect of growth factors. Immunochemical detection of BrdUrd can be used to determine proliferative characteristics of differentiating tissues and to obtain birth dates for actual differentiation events. Studies are also described in which BrdUrd is used to follow the order of DNA replication in specific chromosomes, DNA replication sites in the nucleus and to monitor DNA repair. BrdUrd incorporation has been used as a tool for in situ hybridization experiments.

Simultaneous administration of granulocyte colony-stimulating factor (Filgrastim) and induction chemotherapy in acute lymphoblastic leukemia. A pilot study

The present study was designed to determine whether Filgrastim, a neutrophil-specific hematopoietic growth factor, could be administered simultaneously with intensive induction chemotherapy for adult acute lymphoblastic leukemia (ALL). The effect of Filgrastim on the severity of chemotherapy-induced neutropenia, fever, and infections was assessed in 15 patients treated according to the protocol of the German multicenter ALL (GMALL) trial 04/89. Filgrastim (5 micrograms/kg/day) was given concurrently with successive cycles of cyclophosphamide, cytosine-arabinoside (ara-C), 6-mercaptopurine (6MP), prednisone (PRD), intrathecal methotrexate, and prophylactic cranial irradiation. During the study period the median total duration of severe neutropenia (< 0.5 x 10(9)/l) in 13 evaluable patients was 8 days, individual periods of neutropenia typically were short. Infections occurred in six patients; seven patients remained fever-free during treatment with Filgrastim. We conclude that simultaneous treatment with Filgrastim and chemotherapy in this specific setting is feasible and well tolerated. The efficacy of this treatment approach in terms of overall treatment results requires further testing in a randomized trial.