New horizons in molecular mechanisms underlying Parkinson's disease and in our understanding of the neuroprotective effects of selegiline.

There have been many claims that the selective monoamine oxidase type B (MAO-B) inhibitor selegiline may have distinct properties in slowing the progression of Parkinson's disease (PD). Degeneration of nigro-striatal dopaminergic neurons is the primary histopathological feature of PD. Although many different hypotheses have been advanced, the cause of chronic nigral cell death and the underlying mechanisms remain elusive as yet.

Effect of polyamine depletion on macromolecular synthesis of the malarial parasite, Plasmodium falciparum, cultured in human erythrocytes.

DL-alpha-Difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase, prevented the increases in putrescine and spermidine, but not in spermine, in human erythrocytes infected with the malarial parasite Plasmodium falciparum. The addition of putrescine to these polyamine-depleted cultures restored the normal concentrations of spermidine, whereas that of putrescine even exceeded that of the control cultures. DFMO also inhibited the incorporation of radioactive amino acids into the proteins of parasitized erythrocytes.

[Prognostic factors in myelodysplastic syndromes: analysis of 72 cases].

72 patients were diagnosed as suffering from myelodysplastic syndromes (MDS) according to the FAB classification: 16 patients with refractory anaemia (RA), 11 patients with acquired idiopathic sideroblastic anaemia (AISA), 14 patients with refractory anaemia with an excess of blast cells (RAEB), 7 patients with RAEB in transformation (RAEB/t) and 24 patients with chronic myelomonocytic leukaemia (CMML). The duration of the preleukaemic phase was between 2 and 189 months (median: 15 months); RAEB in transformation and CMML showed a median phase of less than 12 months. Transformation into acute leukaemia (AL) occurred in 46 patients (64%).

Polyamine induced suppression of erythropoiesis in uremia.

The effect of the polyamine spermine previously shown to suppress erythropoiesis in vitro was investigated in a long term animal experiment. Continuous application of spermine by intraperitoneally implanted microperfusion pumps caused a mild hypoproliferative microcytic anemia in normal rats. Furthermore, in 12 patients with advanced renal insufficiency spermine was shown to be markedly elevated.

[Polyamine levels in blood and plasma of patients with malignant melanoma].

The polyamines putrescine, cadaverine, spermidine, spermine, and the amine histamine in whole blood and plasma of 42 patients with malignant melanoma were analysed after cold acid extraction and ion-exchange chromatography by fluorescence detection. Depending on the degree of tumor spreading the patients were grouped into 5 subpopulations; results were statistically compared with the values obtained from a normal population. The mean values of polyamine concentrations in the patient groups were generally not distinguishable from the mean values of the controls.