Mass spectrometric studies on small open-chain piperazine-containing ligands and their transition metal complexes.

Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry was used to characterize the complexes formed between open-chain piperazine-containing ligands and transition metal salts (Cobalt, Copper, Zinc, and Cadmium as chlorides, nitrates, and acetates). Only single-charged complexes were observed, formed of one ligand (L) and mainly one metal ion (M). Since the net charge of the complexes was one, a counterion (X) was attached to some of the complexes, with formation of [L + M + X]+ complexes, and a proton was lost from others, as in [L - H + M]+ complexes. In most cases the composition of the complexes was more dependent on the ligand than the metal salt. Collision-induced dissociation measurements showed that complexes with related composition often differed in structure, or that interactions between the ligand and the metal ion were not alike. The metal ion influenced considerably the fragmentation pathways of the ligands, so that the fragmentation products could be used to deduce the binding sites of the metal. The variations observed in fragmentation behavior of complexes possessing the same ligand but different metal ions can mostly be explained by the ionic radius and electronic configuration of the metal ion. The results indicated a preference of the piperazine ring of the coordinated ligand for the boat conformation.

Mass spectrometric studies on pyridine-piperazine-containing ligands and their complexes with transition metals formed in solution.

Electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) methods were used to study open-chain piperazine-containing ligands (L) and their complexes formed with transition-metal salts. ESI and MALDI measurements were performed with a Fourier transform ion cyclotron resonance (FT-ICR) and a time-of-flight (TOF) mass spectrometer, respectively. Only singly charged complexes, between one ligand and one or several metal ions, were formed in the ESI measurements. Because the net charge was always one, one or several counterions were attached to the complex. Under ESI conditions, the complexes formed between the ligands and metal (Co, Ni, Cu, and Cd) salts were [L + M + X](+), [L + H + M + X(2)](+) and [L + M(2) + X(3)](+) (M = metal ion, X = counterion). In collision induced dissociation reactions the [L + H + M + X(2)](+) complexes easily eliminated one proton and one counterion. Fragmentation pathways were more dependent on the metal ion than the ligand, and elimination of the second counterion occurred with one proton from copper and nickel complexes and with one proton and one hydrogen from cobalt complexes. Differences in the fragmentation of the complexes could be due to electronic configuration of the metal ion. In the MALDI measurements the ratio between the [L + H](+) and [L - H](+) ions varied with the matrix. Fragmentation of the ligands through elimination of 2-methylpyridine end groups occurred with the aromatic matrices containing carboxylic acid and hydroxyl substituents. Ionization of the complexes was not successful with MALDI as the matrix molecules were also attached to the complexes.

Detection of residual tumours in postchemotherapy testicular cancer by FDG-PET.

The aim of this study was to investigate whether 2-(F-18)-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) could reliably detect testicular cancer in patients following chemotherapy. Twenty FDG-PET studies were performed on 15 patients with metastatic seminoma or non-seminoma. Tracer uptake in the PET study was measured by calculating the standardised uptake value (SUV) for the tracer. Nine lesions out of 20 were judged to be positive based on high FDG uptake. Three proved to represent inflammatory changes in non-cancerous tissue. Eleven PET studies were negative. In one of these, viable tumour was found at retroperitoneal lymphadenectomy. The median SUV values of metastatic tumours and benign residual tumours were 2.7 (range 1.6-9.5, n = 10) and 1.7 (range 0.7-5.5, n = 15), respectively. The large overlap of SUVs between these groups was due to the relatively high FDG uptake in inflammatory tissue (median 4.2, range 2.0-5.5, n = 4). The results indicate that FDG imaging of metastatic testicular cancer after chemotherapy has limited value because of a potentially high accumulation of FDG in inflammatory tissues.

Multivariate analysis of prognostic factors in 106 patients with malignant glioma.

The aim of this study was to evaluate the outcome and prognostic factors influencing survival in 106 patients with supratentorial malignant gliomas treated with radiotherapy. The study group included 84 patients treated by surgery and post-operative radiotherapy and 22 patients treated by postbiopsy irradiation. Radiotherapy was delivered to the tumour area with a 2 cm margin, the aimed curative dose was 60 Gy in 6-7 weeks. The 60-month overall survival (Kaplan-Meier) was 20%. Following a univariate analysis, younger age (P < 0.001), longer duration of symptoms (P = 0.009), good performance status after radiotherapy (P < 0.001), other than grade 4 histology (P < 0.001) and higher radiation dose (P < 0.001) were associated with better overall survival rates. Multivariate analysis found that age, symptom duration, histology, extent of symptoms and radiation dose were independent prognostic factors influencing survival. In conclusion, conventional radiotherapy of supratentorial malignant gliomas results in survival that is comparable to results from clinical experiments with different fractionation schedules and radiation with chemotherapy or radiosensitisers. To improve the results, new approaches are needed, especially for patients with the poorest prognosis after standard treatment.