P300-based brain computer interface: reliability and performance in healthy and paralysed participants.

OBJECTIVE: This study aimed to describe the use of the P300 event-related potential as a control signal in a brain computer interface (BCI) for healthy and paralysed participants. METHODS: The experimental device used the P300 wave to control the movement of an object on a graphical interface. Visual stimuli, consisting of four arrows (up, right, down, left) were randomly presented in peripheral positions on the screen. Participants were instructed to recognize only the arrow indicating a specific direction for an object to move. P300 epochs, synchronized with the stimulus, were analyzed on-line via Independent Component Analysis (ICA) with subsequent feature extraction and classification by using a neural network. RESULTS: We tested the reliability and the performance of the system in real-time. The system needed a short training period to allow task completion and reached good performance. Nonetheless, severely impaired patients had lower performance than healthy participants. CONCLUSIONS: The proposed system is effective for use with healthy participants, whereas further research is needed before it can be used with locked-in syndrome patients. SIGNIFICANCE: The P300-based BCI described can reliably control, in 'real time', the motion of a cursor on a graphical interface, and no time-consuming training is needed in order to test possible applications for motor-impaired patients.     

Trisomy of chromosome 10 in two cases of ovarian carcinoma

Simple numerical chromosome aberrations have been observed in tumorigenesis and may point to indicative initiating or early events in tumorigenesis. We have identified two cases of ovarian carcinomas with trisomy of chromosome 10 using conventional GTG-banding and fluorescence in situ hybridization. This is, to our knowledge, the first report of trisomy 10 as a simple karyotypic abnormality observed in ovarian carcinoma. These results suggest that further studies investigating whether chromosome 10 genes are associated with the pathogenesis of some ovarian tumors are warranted.     

Acquisition of different carbapenem resistance mechanisms by an epidemic clonal lineage of Pseudomonas aeruginosa.

Multidrug-resistant isolates of a clonal lineage of Pseudomonas aeruginosa producing the VIM-2 metallo-beta-lactamase (MBL), involved in a large outbreak in an Italian hospital, were compared with MBL-negative strains that had caused outbreaks in two French hospitals. Although the isolates had different carbapenem MICs, the VIM-2-producing isolates from Italy carried identical, or very similar, allelic forms of the oprD gene, harboured a common class 1 integron, belonged to the same multilocus sequence type (ST111), and showed macrorestriction profiles that were related to those of the MBL-negative French strains. These results support the concept of independent acquisition of resistance determinants by members of a widespread clonal lineage of P. aeruginosa.     

Synthesis and purification of the aflatoxin B1-lysine adduct

This work reports the chemical synthesis of aflatoxin B₁ (AFB₁)-lysine based on procedures available in the literature, but using lysine without a protection group in the α-amine group. AFB₁-exo-8,9-epoxide was obtained by epoxidation of AFB₁ with chloroperoxybenzoic acid in dichloromethane and phosphate buffer. Purification and identification of the AFB₁-lysine were conducted by liquid chromatography (LC), and its structure was confirmed by LC with mass spectrometer and diode-array detection. The preparation of AFB₁-lysine using lysine without a protection group in the α-amine group was completed in 24?h, being a practical modification of available methods that can be reproduced in analytical laboratories.