Phagnalon rupestre as a source of compounds active on contact hypersensitivity

The effect of Phagnalon rupestre MeOH extract on dinitrofluorobenzene- and sheep red blood cells-induced hypersensitivity was investigated. Eight compounds were identified: three dimethylallyl-hydroquinone glucosides (1 - 3), 3,5- and 4,5-di-O-caffeoylquinic acid methyl esters (4 and 5), their free carboxyl analogues (6 and 7), and luteolin 7-O-beta-glucoside (8). All were tested for dinitrofluorobenzene-induced contact hypersensitivity inhibitory activity. Flavonoid 8 was the most active (49 % and 79 % inhibition at 24 and 96 h, respectively). The hydroquinones 1, 2 and 3 were effective at 96 h after challenge (62 %, 73 % and 60 % inhibition, respectively), while some of the dicaffeoylquinic derivatives (4 and 7) produced slightly lower reduction of the inflammatory reaction.     

Composition and antifungal activity of the essential oil of Solidago chilensis

Volatile constituents of the essential oils from leaves and inflorescences of Solidago chilensis Meyen were analyzed by GC-FID, GC-MS and 13C-NMR and thirty-six different compounds were identified. Pumiloxide, an unusual labdane diterpene, was found to be one of the major components in both oils (15.3 % and 12.3 %, respectively). Other important constituents were limonene and several sesquiterpenes, mainly gamma-cadinene. The antifungal activity of the leaf oil was assayed against five different strains of filamentous fungi and one yeast. Paper disk agar diffusion test showed human pathogenic dermatophytes to be the most sensitive.     

Pharmacological treatment of obesity

The foundation on which the treatment of obesity rests is made up of the procedures aimed at unbalancing the equation of energy balance in favour of calorie consumption. Pharmacological treatment is aimed at favouring a reduction of calorie intake or stimulating calorie production. Depending on their mechanism of action, the drugs that are used in the treatment of obesity can be divided into appetite inhibitors, inhibitors of food intake or blockers of fat digestion and stimulators of thermogenesis. Amongst the appetite inhibitors, besides the adrenergic agents such as those of the amphetamine type, which are forbidden because of their addictive effect, are the serotonin uptake inhibitors such as dexfenfluramine (withdrawn in 1997) and fluoxetine. The recent commercialisation of sibutramine, a serotonin and norepinephrine reuptake inhibitor with an appetite inhibiting and thermogenesis stimulating effect, offer new perspectives in this field. Amongst inhibitors, mention is deserved by orlistat that inhibits the absorption of upto 30% of ingested fat without causing secondary effects of significance. In the area of thermogenic drugs there are the ephedrine-caffeine association, and the adrenergic beta antagonists, which are still being researched. There are numerous future perspectives amongst which are leptin, analogs of GLP-1 and cholecystokinin and neuropeptide Y antagonists. It is necessary to have reliable predictive elements that make it possible to know the most useful drugs, as well as the sort of patients who will benefit most from the different pharmacological treatments.     

Characterization of an O-glycosylated plaque-associated protein from Alzheimer disease brain

In this work we characterized a 90-kDa glycoprotein from Alzheimer disease (9OAzgp) brain extracts that is recognized by the GalNAc-specific lectin from Amaranthus leucocarpus (ALL), as determined through Western blot. The 90Azgp was purified by electro-elution, and its amino acid sequence determined from peptides obtained after trypsin digestion through MALDI-TOF (Matrix-assisted laser desorption ionization-time of flight), and compared with the relative values obtained from the NCBInr (Swiss-Prot 10/01/2001) database. The 90Azgp showed 32% and 42% homology with the KIAA0310 protein from human brain and the human gastric mucin, respectively. Presence of O-glycosidically linked glycans in the proteins recognized by ALL was confirmed by inhibition of the lectin-glycoprotein interaction through hapten-inhibition assays and also by elimination of the O-glycosidically linked glycans after treatment with O-glycanase from Diplococcus pneumoniae. Electron transmission microscopy confirmed that the receptor recognized by the lectin is processed in the Golgi apparatus of AD neurons. Although the specific role of this glycoprotein has not been identified, considering that the presence of this lectin receptor co-localized with neuritic plaques and in AD sprouting neurons, it could suggest that the O-glycosyl-protein identified by the A. leucocarpus lectin participates in the pathogenesis of neurodegenerative diseases.     

Multisensory contributions to the perception of motion

The ability to process motion is crucial for coherent perception and action. While the majority of studies have focused on the unimodal factors that influence motion perception (see, for example, the other chapters in this Special Issue), some researchers have also investigated the extent to which information presented in one sensory modality can affect the perception of motion for stimuli presented in another modality. Although early studies often gave rise to mixed results, the development of increasingly sophisticated psychophysical paradigms are now enabling researchers to determine the spatiotemporal constraints on multisensory interactions in the perception of motion. Recent findings indicate that these interactions stand over-and-above the multisensory interactions documented previously for static stimuli, such as the oft-cited 'ventriloquism' effect. Neuroimaging and neuropsychological studies are also beginning to elucidate the network of neural structures responsible for the processing of motion information in the different sensory modalities, an important first step that will ultimately lead to the determination of the neural substrates underlying these multisensory contributions to motion perception.