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Dorca-Arévalo J Soler-Jover A Gibert M Popoff MR Martín-Satué M Blasi J 《Veterinary microbiology》2008,131(1-2):14-25
Epsilon-toxin (varepsilon-toxin), produced by Clostridium perfringens type D, is the main agent responsible for enterotoxaemia in livestock. Neurological disorders are a characteristic of the onset of toxin poisoning. varepsilon-Toxin accumulates specifically in the central nervous system, where it produces a glutamatergic-mediated excitotoxic effect. However, no detailed study of putative binding structures in the nervous tissue has been carried out to date. Here we attempt to identify specific acceptor moieties and cell targets for varepsilon-toxin, not only in the mouse nervous system but also in the brains of sheep and cattle. An varepsilon-toxin-GFP fusion protein was produced and used to incubate brain sections, which were then analyzed by confocal microscopy. The results clearly show specific binding of varepsilon-toxin to myelin structures. varepsilon-Prototoxin-GFP and varepsilon-toxin-GFP, the inactive and active forms of the toxin, respectively, showed identical results. By means of pronase E treatment, we found that the binding was mainly associated to a protein component of the myelin. Myelinated peripheral nerve fibres were also stained by varepsilon-toxin. Moreover, the binding to myelin was not only restricted to rodents, but was also found in humans, sheep and cattle. Curiously, in the brains of both sheep and cattle, the toxin strongly stained the vascular endothelium, a result that may explain the differences in potency and effect between species. Although the binding of varepsilon-toxin to myelin does not directly explain its neurotoxic effect, this feature opens up a new line of enquiry into its mechanism of toxicity and establishes the usefulness of this toxin for the study of the mammalian nervous system. 相似文献
22.
C. Gibert J. Chad&#;uf P. Nicot G. Vercambre M. Génard F. Lescourret 《Plant pathology》2009,58(6):1021-1031
The effects of cuticular crack surface area and inoculum density on the infection of nectarine fruits by conidia of Monilinia laxa were studied using artificial inoculations with conidial suspensions and dry airborne conidia during the 2004 and 2005 seasons, respectively. Additionally, the effect of ambient humidity on fruit infection was evaluated in the 2005 experiment. An exploratory analysis indicated that (i) ambient humidity did not significantly explain the observed variability of data, but that (ii) the incidence of fruit infection increased both with increasing inoculum density and increasing surface area of cuticular cracks. The product of these two variables represented the inoculum dose in the cracks, and was used as a predictor of fruit infection in the model. Natural infection in the orchard was observed to increase throughout the season in both 2004 and 2005. The relationship between the probability of fruit infection by M. laxa and the artificially inoculated dose in the cuticular cracks was well described by a logistic regression model once natural inoculum density was taken into account (pseudo R2 = 65%). This function could be helpful for estimating the risk of fruit infection at harvest based on fruit size and natural inoculum density. 相似文献
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Marco I Lopez-Olvera JR Gibert P Abarca L Gauthier D Lavín S 《Zoonoses and public health》2007,54(6-7):278-280
Two free-ranging southern chamois (Rupicapra pyrenaica) - one 4-year-old male and one 3-year-old male - were diagnosed with clinical dermatophytosis in the French and Spanish Eastern Pyrenees respectively. Skin samples were collected for microbiological studies, Trichophyton mentagrophytes being isolated and identified in both animals. The first chamois was found dead at the base of a cliff, and presented with alopecia and scaling on the dorsum and left forelimb. The second chamois showed grey-yellow, rough to raised scaling and crusting skin lesions at the base of the horns, around the eyes, dorsum of the nose, sternum, tail and limbs. Histological examination was carried out only on the second animal. The main lesions were orthokeratotic hyperkeratosis with focal parakeratosis, irregular to papillary epidermal hyperplasia, intracorneal neutrophilic pustules, perivascular to diffuse dermatitis with neutrophilic folliculitis and furunculosis. In those follicles with folliculitis and/or furunculosis, fungal hyphae and arthrospores associated with the follicular keratin and hair shafts were seen. 相似文献
24.
Oró J Updegrove WS Gibert J McReynolds J Gil-Av E Ibanez J Zlatkis A Flory DA Levy RL Wolf C 《Science (New York, N.Y.)》1970,167(3918):765-767
Organogenic elements, mainly carbon, nitrogen, phosphorus, and sulfur are present in the particulate material and in a breccia rock from Tranquillity Base in amounts ranging from 5 to 4200 parts per million. The major compounds of carbon released by heating are carbon monoxide and carbon dioxide; the former predominates. Small amounts of other compounds of carbon have also been observed. Sulfur can be released as hydrogen sulfide by treatment with acid. The carbon isotopic delta(13L)C values are definitely nonterrestrial (+ 13 to + 18.5 per mil). 相似文献
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Spatial distribution,total length frequencies and otolith morphometry as tools to analyse the effects of a flash flood on populations of roach (Rutilus rutilus) 
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下载免费PDF全文 Fabien Morat Pierre Gibert Nathalie Reynaud Baptiste Testi Pierre Favriou Virginie Raymond Georges Carrel Anthony Maire 《Ecology of Freshwater Fish》2018,27(1):421-432
Floods are known to be the major source of natural variability and disturbance in stream ecosystems. However, the management and channelisation of large rivers have impacted the fluvial geomorphology and disconnected the main channel and floodplains used as nurseries by many species of fish. This study examines the influence of a first autumnal flood event of the Ardèche River on the roach population, Rutilus rutilus (Linnaeus, 1758), in the Caderousse reach on the Rhône River. This influence was evaluated through an analysis of the spatial distribution for the abundance and size of juvenile roach and an analysis of otolith shape. Juvenile roach from the three sections of the reach formed well‐defined local populations before and after the flood event. Juvenile roach were always more abundant in the less modified section (BPS) of the river than in the other sections (RES and TAIL). While the original primary river channel was directly impacted by the flash flood, no significant difference in otolith shape was observed before or after the flash flood. Our results suggest that this part of the reach provides refuge habitats used by fish during high flow events. 相似文献
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