Effects of propiconazole on extra-cellular enzymes involved in nutrient mobilization during <Emphasis Type="Italic">Trametes versicolor</Emphasis> wood colonization     

Serge Lekounougou  Jean-Pierre Jacquot  Philippe Gérardin  Eric Gelhaye 《Wood Science and Technology》2008,42(2):169-177

The effects of propiconazole on extra-cellular enzyme levels in Trametes versicolor have been investigated during wood colonization and degradation. The working hypothesis was that the biocide could alter metabolic pathways, which could lead to an alteration of extra-cellular enzyme production. In the presence of a propiconazole sub-lethal concentration, the wood degradation rate decrease concomitantly with the lag phase of fungal development observed during wood colonisation. The pattern of production of enzymes involved in polysaccharide degradation (β-glucosidases, glucuronidases, cellobiohydrolases), nitrogen (leucine aminopeptidase) and phosphorus (acid phosphatase) mobilization was only slightly altered in the presence of the biocide. In experiments performed in the presence of propiconazole, there was a strong induction of chitinases at the beginning of the colonization process. Addition of caffeine, a pleiotropic drug, which is also a chitinase inhibitor, together with propiconazole resulted in synergistic inhibition of the fungal growth. The implication of these results in the development of a new wood preservation strategy is discussed.  相似文献   

Enhanced excretion of DDT and metabolites in rats treated with trans,trans-muconate     

Serge R. Boileau  Jean J. Simard  Jean R. Wouters  Jean G. Alary  D.Jit S. Arora 《Pesticide biochemistry and physiology》1985,24(3):336-342

The interactions between trans,trans-muconate and p,p′-DDT were examined. Male Wistar rats were injected intraperitoneally with 6.67 mg kg^?1 [¹⁴C]p,p′-DDT. Two hours later the experimental animals received orally a solution of sodium muconate (75 mg kg^?1, 0.3 ml) in physiological saline, pH 7.2; control animals received an equal volume of physiological saline. Treatment was repeated every 12 hr for 10 days. Sodium muconate does not modify urinary excretion of labeled compounds, yet it reduces body burden by accelerating the excretion rate of these compounds in rat feces. This action was observed only during the first 24 hr after the animals were exposed to p,p′-DDT.  相似文献   

Establishment of reference values of the caudal vena cava by fast‐ultrasonography through different views in healthy dogs          下载免费PDF全文

Elodie Darnis  Soren Boysen  Anne‐Christine Merveille  Loïc Desquilbet  Serge Chalhoub  Kris Gommeren 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2018,32(4):1308-1318

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Ecology. Coral reefs and the global network of Marine Protected Areas     

Mora C  Andrèfouët S  Costello MJ  Kranenburg C  Rollo A  Veron J  Gaston KJ  Myers RA 《Science (New York, N.Y.)》2006,312(5781):1750-1751

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Cross-protection of Salmonella abortusovis, S. choleraesuis, S. dublin and S. gallinarum in mice induced by S. abortusovis and S. gallinarum: bacteriology and humoral immune response     

Bernard S  Boivin R  Menanteau P  Lantier F 《Veterinary research》2002,33(1):55-69

Cross-protection induced by primary infection with Abortusovis and Gallinarum was examined against challenge injection with these Salmonella serotypes as well as with Dublin and Choleraesuis, the other virulent serotypes. Abortusovis induced efficient protection against the other Salmonella. Gallinarum was ineffective against Choleraesuis. Even with low multiplication in mice, the Gallinarum J91 strain induced a weak but significant protection against Dublin (same O group serotype). The antibodies in the blood of mice were tested with ELISA specific for the Salmonella antigens used to prime or to challenge animals. The Gallinarum J91 strain was detected to be more antigenic in ELISA than the other Salmonella antigens. It is difficult to conclude on a correlation between IgM or IgG antibodies and induction of protection, because of the variability in immune response according to the different serotype used. Nevertheless, the negative linkage between a number of bacteria in the spleen of mice challenged with Gallinarum and Dublin, and the level of IgM and IgG antibodies specific for the challenging serotype, showed that humoral immune response could be one element of cross-protection, mainly by the immune response against the same O serotype.  相似文献   

SLO angiography: arterio-venous filling times in monkey and minipig     

Rosolen SG  Saint-Macary G  Gautier V  Le Gargasson JF 《Veterinary ophthalmology》2002,5(1):19-22

Confocal scanning laser ophthalmosocope (cSLO) is a new technique which enables ocular fundus image recording and dynamic retinal angiography to be performed. The ocular fundus image is acquired sequentially, point by point, and is reconstructed on a video monitor at the rate of 25 images per second. The aim of this paper is to evaluate the feasibility of measuring retinal arterio‐venous filling times (AVFT) with a I + Tech cSLO. Three young adult cynomolgus monkeys and three young adult Göttingen minipigs were used as experimental models. All animals were anesthetized using a zolazepam + tiletamine mixture injected intramuscularly; heart rate and rectal temperature were monitored and corneal irrigation was regularly performed. For all subjects, prior to examination, hematocrit and globe axial length were measured. The images were recorded, stabilized and analyzed. The retinal examination consisted of retinal images with 40° field cSLO, retinal fluorescein angiography and arterio‐venous 50% filling time measurements. For each subject all images were easily recorded while keeping the animals in a normally lighted room without having to use any additional optical device. AVFT using an I + Tech cSLO is easily performed in monkeys and minipigs. AVFT measurements in minipigs and monkeys are similar. These results suggest that minipigs can replace monkeys as an experimental species for AVFT investigations.  相似文献   

The effect of the mode of application on the toxicity of Androctonus australis hector insect toxin     

Serge De Dianous  Pierre R. Carle  Herv Rochat 《Pest management science》1988,23(1):35-40

The toxicity of the insect toxin from the venom of the scorpion Androctonus australis Hector (AaH IT) was assayed using several ethods of application on various insect species. Activity was only demonstrated by opical application on Musca domestica. Three different solvents were assayed: ethanol + water (50 + 50 by volume), acetone + water (80 + 20 by volume) and acetone + dimethyl sulphoxide (50 + 50 by volume). When using the last two mixtures, LD₅₀ was found to be 1 μg 100 mg^?1 fly. When this activity is compared to that of five synthetic insecticides tested in the same conditions, AaH IT is about 1-5 times more active than propoxur and DDT, 10 times more active than malathion but 200 times less active than deltamethrin. No activity was observed against Aphis craccivora at 15 mg m^?2 in surface-contact tests on glass, or against Culex pipiens pipiens larvae at 2 × 10⁵ ng litre^?1 in water.  相似文献   

Myeloperoxidase concentration in bronchoalveolar lavage fluid from healthy horses and those with recurrent airway obstruction          下载免费PDF全文

Tatiana Art  Thierry Franck  Pierre Lekeux  Brieuc de Moffarts  Laurent Couëtil  Martine Becker  Serge Kohnen  Ginette Deby-Dupont    Didier Serteyn 《Canadian journal of veterinary research》2006,70(4):291-296

The aim of this work was to measure the myeloperoxidase (MPO) concentration in bronchoalveolar lavage (BAL) fluid collected from horses with recurrent airway obstruction (RAO), both in crisis and in remission, as well as from healthy horses. Seven horses with RAO were exposed to moldy hay until the maximum change in pleural pressure was greater than 1.5 kPa. At that point, BAL was performed, and the total cell counts and percentages in the fluid were immediately determined. To measure the MPO concentration in BAL-fluid supernatant, we used a specific enzyme-linked immunosorbent assay with polyclonal antibodies against equine MPO. The tests were repeated on the horses with RAO after they had spent 2 mo on pasture. Six healthy horses serving as controls underwent the same tests. The absolute and relative neutrophil counts and the MPO concentration in the BAL fluid were significantly greater in the horses with an RAO crisis than in the control horses. After 2 mo on pasture, the horses that had been in RAO crisis were clinically normal, and their neutrophil counts and MPO levels in BAL fluid had significantly decreased; during remission their neutrophil counts were not significantly different from those in the healthy horses, but their MPO concentration remained significantly higher. This study showed that determining the MPO concentration in a horse's BAL fluid is technically possible and that during remission from RAO the concentration remains higher than normal. Thus, MPO may be a marker of neutrophil presence and activation in the lower airways.  相似文献   

Epidemiological Characteristics of Angular Leaf Spot of Bean: A Systems Analysis     

Delphine?Allorent  Serge?SavaryEmail author 《European journal of plant pathology / European Foundation for Plant Pathology》2005,113(4):329-341

In this review, available knowledge on angular leaf spot (ALS) of bean, caused by Phaeoisariopsis griseola, is analysed and synthesised. This is done through a systems-analytical approach, and successive flowcharts of the system, in order to identify knowledge gaps and guide further research. Six connected sub-models of the ALS monocycle are used as a framework: lesion establishment, lesion extension, defoliation, sporulation, spore liberation, and spore deposition. Each of the sub-models enables the linking of processes to various effects of environmental (physical and host) factors. Disease-induced defoliation is one feature of the pathosystem, leading to a depletion of infectious tissues from the canopy, which are transferred to the ground. Consequences of defoliation may include: strong reductions of the amount of inoculum and of vacant sites in the canopy, limited maximum disease severity, and progressive accumulation of inoculum below the canopy, which may become important a later stage of disease epidemics. These elements are hypothesised to explain the typical behaviour of ALS epidemics in the field, especially late onset, high apparent rate of disease increase, and low level of terminal disease severity in the standing canopy. Epidemiological consequences of lesion expansion, sporulation, and survival of spores deposited onto the canopy are other knowledge gaps in this pathosystem.  相似文献   

Quantifying and Modelling the Mobilisation of Inoculum from Diseased Leaves and Infected Defoliated Tissues in Epidemics of Angular Leaf Spot of Bean     

Delphine?Allorent  Laetitia?Willocquet  Aloisio?Sartorato  Serge?SavaryEmail author 《European journal of plant pathology / European Foundation for Plant Pathology》2005,113(4):377-394

Daily multiplication factor (number of daughter lesions per mother lesion per day) values were experimentally measured in four replications of a monocyclic experiment on angular leaf spot (ALS) of bean, where sources of inoculum were artificially established within a bean canopy, on the ground (defoliated infected leaves), or both. Daily multiplication factor of lesions in the canopy (DMFRc) was higher than that of infectious, defoliated tissues (DMFRd) in all replications. Both DMFRc and DMFRd were strongly reduced under dry compared to rainy conditions. Under rainy conditions for spore dispersal DMFRd was about two to three times smaller than DMFRc. Defoliated leaves may nevertheless represent a significant source of infection, depending on the amount of infectious tissues. Mother lesions within the canopy generated more daughter lesions in the medium (or lower) layers of the canopy than at its upper level (DMFRc higher at the medium and lower layers of a canopy), whereas DMFRd values seemed to decrease with height in the canopy. A mechanistic simulation model that combines host growth and disease-induced defoliation was designed to simulate the respective contributions of the two components of the dual inoculum source of a diseased canopy (infected foliage and defoliated infectious tissues), and varying infectious periods in both sources. Simulations suggest that higher DMFRc values have a large polycyclic effect on epidemics whereas that of DMFRd is small, and that large effects of the infectious period of lesions in the canopy are found when DMFRc is high. Simulations using experimentally measured DMFRc and DMFRd values indicated much stronger epidemics in rainy compared to dry conditions for spore dispersal, but disease persistence in the latter. The implications of considering a dual source of inoculum in the course of a polycyclic process are discussed with respect to epidemic thresholds.  相似文献