Restoring voluntary control of locomotion after paralyzing spinal cord injury

Half of human spinal cord injuries lead to chronic paralysis. Here, we introduce an electrochemical neuroprosthesis and a robotic postural interface designed to encourage supraspinally mediated movements in rats with paralyzing lesions. Despite the interruption of direct supraspinal pathways, the cortex regained the capacity to transform contextual information into task-specific commands to execute refined locomotion. This recovery relied on the extensive remodeling of cortical projections, including the formation of brainstem and intraspinal relays that restored qualitative control over electrochemically enabled lumbosacral circuitries. Automated treadmill-restricted training, which did not engage cortical neurons, failed to promote translesional plasticity and recovery. By encouraging active participation under functional states, our training paradigm triggered a cortex-dependent recovery that may improve function after similar injuries in humans.     

Viability and cell death of synovial fluid neutrophils as diagnostic biomarkers in equine infectious joint disease: a pilot study

Synovial fluid samples from culture-confirmed infected joints (n=13), joints with pronounced non-infectious synovitis (n=11) and healthy joints (n=14) were collected from 24 equine patients and seven slaughterhouse horses. The samples from the joints with non-infectious synovitis and healthy joints served as negative controls. After isolation, counting and identification of neutrophils, the percentage viability, and the proportion apoptotic and necrotic neutrophils were determined by flow cytometry. Viability was significantly higher in infected samples compared to the controls. A significant difference in cell death type was observed, with apoptosis predominating in infected joints, and necrosis being more present in joints with pronounced non-infectious synovitis and healthy joints. The results of this pilot study suggest that flow cytometric analysis of neutrophil viability and cell death dynamics may assist the discrimination between infected and non-infected joints.     

Herd-specific strains of Mycoplasma bovis in outbreaks of mycoplasmal mastitis and pneumonia

Mycoplasma bovis causes severe economic losses in livestock production, particularly on the Northern American continent and more recently also in continental Europe. The aim of the current study was to evaluate whether the recently emerging outbreaks were due to a particular clone or strain of M. bovis or whether these outbreaks are due to multiple infectious strains of M. bovis. The study is based on the analysis M. bovis isolated from cattle of herds with outbreaks of mycoplasmal mastitis or pneumonia from geographically non related parts of Switzerland. M. bovis isolates were typed by insertion sequence (IS) element analysis based upon ISMbov1 and ISMbov2 southern-blot hybridization. We observed a strong divergence of M. bovis strains among affected herds which mostly were herd specific. This argues against the assumption that a recent infiltration of a particular clone of M. bovis is the cause of the perilous emerging outbreaks. The study suggests that transmission occurs from animal to animal most probably via milk.     

Escherichia coli induces DNA double-strand breaks in eukaryotic cells

Transient infection of eukaryotic cells with commensal and extraintestinal pathogenic Escherichia coli of phylogenetic group B2 blocks mitosis and induces megalocytosis. This trait is linked to a widely spread genomic island that encodes giant modular nonribosomal peptide and polyketide synthases. Contact with E. coli expressing this gene cluster causes DNA double-strand breaks and activation of the DNA damage checkpoint pathway, leading to cell cycle arrest and eventually to cell death. Discovery of hybrid peptide-polyketide genotoxins in E. coli will change our view on pathogenesis and commensalism and open new biotechnological applications.     

A Multivariate Data Analysis of the Clam Ruditapes Decussatus as Sentinel Organism of the Bizerta Lagoon (Tunisia)

From May 1998 to May 1999, the clams Ruditapes decussatus were collected each month at three stations of the Bizerta lagoon. This paper represents a synthesis between the results already published of catalase (CAT) activity, of glutathione S-transferase (GST) activity and acetylcholinesterase (AChE) activity measured in the clams. Hydrological parameters (temperature, salinity, dissolved oxygen, pH) were determined. Microbial loads (total aerobic bacteria, faecal bacteria and Vibrionaceae) were analyzed in the clams and the sediments. A global Principal Component Analysis was performed including all parameters. On the first principal axis, the temperature, salinity and bacterial loads as well as CAT activities were important factors always opposed to dissolved oxygen, whereas, on the second axis, AChE activity was opposed to pH. Principal Component Analyses were also carried out for results at each station with all parameters. CAT activities were generally high in summer from July to October. AChE activities were low during the months of January, February and March at one station whereas these low activities were shifted to the months of May, June and July at the two other stations. Among the biochemical biomarkers studied, the variations in CAT activities appeared to be the most significant factor of the multivariate analysis. The variations in AChE activity were also significant whereas those in GST activity appeared to be less significant.     

Application of multielement stable isotope ratio analysis to the characterization of French, italian, and spanish cheeses

The stable isotope ratios (delta13C, delta15N, and delta34S of casein and delta13C and delta18O of glycerol) measured by IRMS of French, Italian, and Spanish cheeses are presented and discussed. Variability factors such as animal-feeding regimen, geographical origin, and climatic and seasonal conditions were studied to check the possibilities of cheese characterization offered by each isotopic parameter. Delta13C values of both casein and glycerol appeared to be strongly correlated to the amount of maize in the animal diet. Delta15N and delta34S of casein proved to be mostly influenced by the geoclimatic conditions of the area (aridity, closeness to the sea, altitude). Delta18O of glycerol was more dependent on the geographical origin of the cheeses and on climatic/seasonal parameters. By applying a multivariate stepwise canonical discriminant analysis, good discrimination possibilities for the different European cheeses were obtained, confirmed by the classification analysis, when >90% of the samples were correctly reclassified.     

Treatment of Air Polluted with Xylenes using a Biofilter Reactor

Biofiltration of air polluted by VOCs is now beingrecognized by the industrial and research communitiesto be an effective and viable alternative for theclassical environmental technologies. While a numberof biological aspects of the biofiltration process arewell understood, the effect of certain engineeringparameters such as temperature, pressure drop,bacterial count, etc., remained ambiguous especiallywhen several isomers have to be removedsimultaneously. In this paper are reported theresults of purification of air containing vapors ofxylenes in a laboratory-scale biofilter reactor. Thelatter is a packed bed of peat balls particlesspecifically designed and produced for this purpose. Three types of micro-organisms strains werescrutinizingly selected and immobilized on thefiltering material. Xylenes entering the biofilter ata relatively high inlet load (110 g m^-3 h^-1)are removed with an elimination capacity of60 g m^-3 h^-1 (at steady state). Theexperimental results obtained on the reduction ofxylenes were satisfactorily represented by thegeneralized Ottengraf's model.     

Molecular Diversity of Agriculturally Important Aspergillus Species

Although Aspergillus species are not usually considered as serious plant pathogens, Aspergilli are frequently encountered in plant products. The most important consequence of their presence is mycotoxin contamination. The main mycotoxins produced by Aspergilli are the aflatoxins, ochratoxin A and patulin, which are produced by a variety of Aspergillus species in different plant commodities. Phylogenetic analysis of sequences of the ribosomal RNA gene cluster is useful for clarifying taxonomic relationships among toxigenic Aspergilli causing pre- and postharvest contamination of agricultural products. Molecular data has enabled us to clarify the taxonomy of black Aspergilli, A. flavus and its relatives, and sections Circumdati and Clavati, which include ochratoxin and patulin-producing species. Phylogenetically unrelated species were found to produce the same mycotoxins, indicating that mycotoxin-producing abilities of the isolates have been lost (or gained) several times during the evolution of the genus. The data also indicate that biosynthetic gene-based probes are necessary for molecular detection of these mycotoxin-producing organisms. The organisation of the biosynthetic genes of patulin and ochratoxins is unknown, although experiments are in progress in several laboratories to clarify the genetic background of biosynthesis of these mycotoxins. Identification of biosynthetic genes responsible for mycotoxin production is essential for clarifying the evolution of mycotoxin biosynthesis in Aspergilli, and to develop specific gene probes for the detection of mycotoxin-producing Aspergilli in agricultural products.