H.S.P. Garritsen

Raman microspectroscopic approach to the study of human granulocytes

A sensitive confocal Raman microspectrometer was employed to record spectra of nuclei and cytoplasmic regions of single living human granulocytes. Conditions were used that ensured cell viability and reproducibility of the spectra. Identical spectra were obtained from the nuclei of neutrophilic, eosinophilic, and basophilic granulocytes, which yield information about DNA and protein secondary structure and DNA-protein ratio. The cytoplasmic Raman spectra of the three cell types are very different. This was found to be mainly due to the abundant presence of peroxidases in the cytoplasmic granules of neutrophilic granulocytes (myeloperoxidase) and eosinophilic granulocytes (eosinophil peroxidase). Strong signal contributions of the active site heme group(s) of these enzymes were found. This paper illustrates the potentials and limitations for Raman spectroscopic analysis of cellular constituents and processes.

Interleukin-2 Postremission Therapy in Acute Myeloid Leukemia (AML): In Vitro and In Vivo Effects of a Five Day Continuous Infusion of IL-2 on Phenotype and Function of Peripheral Lymphocytes

In vitro studies have demonstrated the anti-leukemic effect of IL-2 stimulated cytotoxic lymphocytes on allogeneic leukemic blasts prompting clinical trials with IL-2 in vivo. We initiated a phase II study with IL-2 in 6 patients with acute myeloid leukemia. The patients were in second or third remission after successful salvage treatment for relapse. All patients had received a standardized first line treatment according to the protocol of the German AML cooperative group. Salvage treatment consisted of sequential high dosed cytosine-arabinoside and mitoxantrone (sHAM). the postremission IL-2 therapy consisted of continuous intravenous infusion of IL-2 in a dosis of 3 × 106 IU/m/day over 5 days, four weeks later the next cycle was given. Lymphocyte subsets in the peripheral blood and their IL-2 receptor expression of these patients were studied on day 0, 2 and 5 of the IL-2 cycle using multiparameter flow cytometry. 13 IL-2 cycles in 6 patients were analysed.