Materials from Argentina of adventitious species of Viola were examined and four species were confirmed: V. arvensis, V. metajaponica, V. odorata and V. tricolor. V. metajaponica is lectotypified, and the identity of V. japonica is discussed. A key to identify the species, their descriptions, illustrations, ecology and geographic distribution are given.

Se revisan materiales de entidades adventicias de Viola en Argentina y se comprueba la presencia de 4 especies diferentes: V. arvensis, V. metajaponica, V. odorata y V. tricolor. V. metajaponica es lectotipificada y se discute la identidad de V. japonica. Las especies son descriptas e ilustradas, y se provee una clave diacrítica, además de datos de ecología y distribución geográfica.

Parkinson's disease, a major neurodegenerative disorder in humans whose etiology is unknown, may be associated with some environmental factors. Nocardia otitidiscaviarum (GAM-5) isolated from a patient with an actinomycetoma produced signs similar to Parkinson's disease following iv injection into NMRI mice. NMRI mice were infected intravenously with a non-lethal dose of 5 x 10(6) colony forming units of N. otitidiscaviarum (GAM-5). Fourteen days after bacterial infection, most of the 60 mice injected exhibited parkinsonian features characterized by vertical head tremor, akinesia/bradykinesia, flexed posture and postural instability. There was a peak of nocardial growth in the brain during the first 24 h followed by a decrease, so that by 14 days nocardiae could no longer be cultured. At 24 h after infection, Gram staining showed nocardiae in neurons in the substantia nigra and occasionally in the brain parenchyma in the frontal and parietal cortex. At 21 days post-infection, tyrosine hydroxylase immunolabeling showed a 58% reduction of tyrosine hydroxylase in the substantia nigra, and a 35% reduction of tyrosine hydroxylase in the ventral tegmental region. Dopamine levels were reduced from 110 ± 32.5 to 58 ± 16.5 ng/mg protein (47.2% reduction) in brain from infected mice exhibiting impaired movements, whereas serotonin levels were unchanged (191 ± 44 protein in control and 175 ± 39 ng/mg protein in injected mice). At later times, intraneuronal inclusion bodies were observed in the substantia nigra. Our observations emphasize the need for further studies of the potential association between Parkinson's disease or parkinsonism-like disease and exposure to various nocardial species.