An approach to the study of primitive thrombocythemia (PT) megakaryocytes by means of Fourier transform infrared microspectroscopy (FT-IR-M).

Chronic myeloid leukemia (CML), polycythemia vera (PV), idiopathic myelofibrosis (IM) and primary thrombocythemia (PT) are myeloproliferative diseases of clonal origin. Megakaryocyte series are commonly involved in these disorders. In a previous paper of us, megakaryocytes (MKs) from PV and PT patients were shown to be more pathological with respect to the MKs from CML. This paper describes a Fourier transform infrared microspectroscopy (FT-IR-M) study analyzing the cytoplasm and nucleus areas of MKs from thrombocythemic patients which exhibited numerous giant cells (from 100 to 190 microm in diameter). The size of these cells makes it possible to analyze the cell parts using FT-IR-M technique. The infrared determinations on 10 single MKs for each case examined in these two different cell regions revealed spectral differences with a high degree of reproducibility. Finally, the spectra of whole MKs from normal donors and from thrombocythemic patients were also compared.

New possibilities of research in chronic lymphatic leukemia by means of Fourier transform-infrared spectroscopy--II.

Ten samples of lymphocytes coming from patients affected by chronic lymphatic leukemia and ten samples from normal subjects were studied by FT-IR spectroscopy. Spectral differences observed between the two kinds of cells correspond to an increase of the intensities, in the leukemic samples with respect to the normal ones, of the bands corresponding mainly to PO2- symmetrical and asymmetrical stretching vibrations of DNA. The ratios of the integrated areas of the band at 1080 cm-1 mainly involving the symmetrical stretching vibration of the O-P-O linkages of DNA, and of the band at 1540 cm-1, due to the proteic components of the lymphocytes, assume different values for the two kinds of cells. These ratios can constitute an additional marker to diagnose chronic lymphatic leukemia and may be usefully employed to evidence the early phases of the disease.

Analytical infrared spectral differences between human normal and leukaemic cells (CLL)--I.

Two series of normal and leukaemic lymphocytes were examined by infrared spectroscopy in order to try to find spectral differences connected with chemical and biological modifications. The bands at 965 and 530 cm-1 present only in the spectra of leukaemic lymphocytes, assume particular significance. The C-H stretching region furnishes useful indications about the different ratios of the methyl groups compared with the methylene ones in the two cases. The infrared bands characteristic of the leukaemic lymphocytes seem to be due to chemical modifications not involving the DNA chain.