Molecular characterization of Hepatitis E virus detected in swine farms in the province of Quebec   总被引：1，自引：0，他引：1       下载免费PDF全文

Pierre Ward  Peter Müller  Ann Letellier  Sylvain Quessy  Carole Simard  Yvon-Louis Trottier  Alain Houde    Julie Brassard 《Canadian journal of veterinary research》2008,72(1):27-31

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Effect of topical application of 2% lidocaine gel on corneal sensitivity of clinically normal equine eyes     

Alain Regnier  Iris Berton  Didier Concordet  Jean-Yves Douet 《Veterinary anaesthesia and analgesia》2018,45(2):158-164

Objective

To assess the degree and duration of corneal anaesthesia provided by topical application of a non-ophthalmic 2% lidocaine gel in horses.

Study design

Experimental, ‘blinded’, randomized prospective study.

Animals

Twelve adult horses without relevant ocular abnormalities.

Methods

Baseline corneal touch threshold (CTT) measurements were obtained bilaterally by use of a Cochet–Bonnet aesthesiometer just prior to topical treatment. A volume of 0.2 mL of 2% lidocaine gel was administered in one randomly selected eye and the same volume of a viscous lubricant in the other eye to serve as control. The CTT value was measured on both eyes 5, 10, 20, 30, 45, 60, 75 and 90 minutes after drug application. The potential for local adverse effects following lidocaine gel application was also evaluated.

Results

Mean CTT baseline measurements were not significantly different (p > 0.05) between the control eyes (3.41 ± 0.56 cm) and those subsequently treated with the lidocaine gel (3.50 ± 0.64 cm). In control eyes, no significant changes in corneal sensitivity (p > 0.05) occurred over time during the study period. By contrast, a marked reduction in corneal sensitivity was observed after lidocaine application, with mean CTT values significantly lower (p < 0.001) than those of the control eyes from 5 to 75 minutes. A steady-state maximal corneal anaesthesia was present from 10 to 45 minutes after lidocaine gel application with mean CTT values ranging from 0.21 to 0.45 cm. Corneal epithelial irregularities were detected in three lidocaine-treated eyes, but spontaneous resolution occurred within 24 hours.

Conclusions and clinical relevance

Deep and sustained corneal anaesthesia is achieved after application of 2% lidocaine gel to the equine eye, with minimal changes in the corneal epithelium. It might be useful for minor ophthalmic surgeries performed in the standing sedated horse.  相似文献   

Early infections by myxoma virus of young rabbits (Oryctolagus cuniculus) protected by maternal antibodies activate their immune system and enhance herd immunity in wild populations     

Stéphane Marchandeau  Dominique Pontier  Jean-Sébastien Guitton  Jér?me Letty  David Fouchet  Jacky Aubineau  Francis Berger  Yves Léonard  Alain Roobrouck  Jacqueline Gelfi  Brigitte Peralta  Stéphane Bertagnoli 《Veterinary research》2014,45(1):26

The role of maternal antibodies is to protect newborns against acute early infection by pathogens. This can be achieved either by preventing any infection or by allowing attenuated infections associated with activation of the immune system, the two strategies being based on different cost/benefit ratios. We carried out an epidemiological survey of myxomatosis, which is a highly lethal infectious disease, in two distant wild populations of rabbits to describe the epidemiological pattern of the disease. Detection of specific IgM and IgG enabled us to describe the pattern of immunity. We show that maternal immunity attenuates early infection of juveniles and enables activation of their immune system. This mechanism associated with steady circulation of the myxoma virus in both populations, which induces frequent reinfections of immune rabbits, leads to the maintenance of high immunity levels within populations. Thus, myxomatosis has a low impact, with most infections being asymptomatic. This work shows that infection of young rabbits protected by maternal antibodies induces attenuated disease and activates their immune system. This may play a major role in reducing the impact of a highly lethal disease when ecological conditions enable permanent circulation of the pathogen.  相似文献   

Sensitivity and permissivity of Cyprinus carpio to cyprinid herpesvirus 3 during the early stages of its development: importance of the epidermal mucus as an innate immune barrier     

Maygane Ronsmans  Maxime Boutier  Krzysztof Rakus  Frédéric Farnir  Daniel Desmecht  Fabien Ectors  Micha?l Vandecan  Fran?ois Lieffrig  Charles Mélard  Alain Vanderplasschen 《Veterinary research》2014,45(1)

Cyprinid herpesvirus 3 (CyHV-3) causes a lethal disease in common and koi carp (Cyprinus carpio). The present study investigated the ability of CyHV-3 to infect common carp during the early stages of its development (from embryos to fingerlings) after inoculation by immersion in water containing the virus. Fish were inoculated at different times after hatching with a pathogenic recombinant CyHV-3 strain expressing luciferase. The sensitivity and permissivity of carp to CyHV-3 were investigated using in vivo bioluminescence imaging. The susceptibility of carp to CyHV-3 disease was investigated by measuring the survival rate. Carp were sensitive and permissive to CyHV-3 infection and susceptible to CyHV-3 disease at all stages of development, but the sensitivity of the two early developmental stages (embryo and larval stages) was limited compared to later stages. The lower sensitivity observed for the early developmental stages was due to stronger inhibition of viral entry into the host by epidermal mucus. In addition, independent of the developmental stage at which inoculation was performed, the localization of light emission suggested that the skin is the portal of CyHV-3 entry. Taken together, the results of the present study demonstrate that carp are sensitive and permissive to CyHV-3 at all stages of development and confirm that the skin is the major portal of entry after inoculation by immersion in infectious water. The results also stress the role of epidermal mucus as an innate immune barrier against pathogens even and especially at the early stages of development.  相似文献   

Size and dispersion of urticating setae in three species of processionary moths     

Edoardo PETRUCCO TOFFOLO  Daniel ZOVI  Chiara PERIN  Paolo PAOLUCCI  Alain ROQUES  Andrea BATTISTI  Helmuth HORVATH 《Integrative zoology》2014,9(3):320-327

Larvae of the processionary moths of the Palaearctic region bear urticating setae that are released against vertebrate predators, especially insectivorous birds. A few species are pests of forest and urban trees and, consequently, may threaten human and animal health during outbreaks, causing dermatitis, conjunctivitis and respiratory distress. Although some studies provide detailed information about the setae, particularly those of the pine processionary moth Thaumetopoea pityocampa, there is little knowledge on the morphological traits of the setae and their release by the larvae. In the present study we identify major traits of the setae of 3 species of processionary moth, T. pityocampa, T. pinivora and T. processionea, which are potentially helpful in the understanding of setae dynamics in the environment: (i) diameter and length of setae and (ii) analysis of dynamical properties of the setae in the airborne state. Setae are highly variable in size, with bimodal distribution in T. pityocampa and T. pinivora; in these 2 species, short and long setae are interspersed within the integument fields where they occur. The difference in the seta size has important consequences in dispersion, as smaller setae can spread 5 times further than their bigger counterparts. This information is relevant for a full understanding of the defensive importance of larval setae against natural enemies of the processionary moths, as well for elucidating the importance of the processionary setae as air pollutants, both close to the infested trees and at longer distances.  相似文献   

Tree microhabitats at the stand scale in montane beech–fir forests: practical information for taxa conservation in forestry     

Laurent Larrieu  Alain Cabanettes  Antoine Brin  Christophe Bouget  Marc Deconchat 《European Journal of Forest Research》2014,133(2):355-367

Recent studies have highlighted the key role of tree microhabitats in forest habitat complexity and have suggested using them as surrogates for local taxonomic biodiversity. However, few practical guidelines have been published to help foresters in managing microhabitats at the stand scale. This paper provides scientific background information to help to develop such guidelines. We surveyed trees in nine long-unmanaged beech–fir forests to model tree microhabitat occurrence and diversity at the tree level. Data were upscaled to a size range of tree cluster, i.e., at the tree population scale, by aggregating observed values of microhabitat occurrence. Accumulation curves were used to estimate the minimum number of trees required to make all the microhabitat types available. Two managed forests were then studied to quantify management effects on microhabitats. Diameter at breast height (dbh) and tree species, respectively, explained 16 and 10 % of the variations in the number of microhabitat-bearing trees, and 21 and 10 % for the number of microhabitat types. Beech trees and firs with a dbh of less than dbh 50 and 65 cm, respectively, did not ensure the provision of all microhabitat types. At least 20 ha of unmanaged forest were necessary to conserve all the microhabitat types. Current management practices have reduced the number of microhabitat-bearing beeches both by reducing the number of very large trees (dbh > 67.5 cm) and by tree selection within mid-size diameters. For fir, only the logging of very large trees (dbh > 62.5 cm) negatively affected microhabitats. These figures may inspire guidelines for conservation-friendly forestry.  相似文献   

Potential spread of the pine processionary moth in France: preliminary results from a simulation model and future challenges     

Christelle Robinet  Jérôme Rousselet  Alain Roques 《Annals of Forest Science》2014,71(2):149-160

Context

Some forest insect pests are currently extending their range as a consequence of climate warming. However, in most cases, the evidence is mainly based on correlations and the underlying mechanism is not clearly known.

Aims

One of the most severe pests of pine forests in Europe, the pine processionary moth, Thaumetopoea pityocampa, is currently expanding its distribution as a result of climate warming and does not occupy entirely its potential habitat. A model describing its spread was developed to simulate its potential range in France under various climate change scenarios.

Methods

The spread model was divided into several sub-models to describe the growth, survival and dispersal of the species. The model was validated on the observed change of species distribution, its sensitivity was tested, and spread scenarios were simulated for the future.

Results

The model shows that climate warming initiated the species range expansion in France since the early 1990s. The spread is now limited by dispersal capability, but human-mediated dispersal could accelerate the range expansion.

Conclusion

Species range expansion is an indicator of climate change. However, time lags can appear due to limited dispersal capabilities, and human-mediated dispersal could create satellite colonies and artificially accelerate the spread.  相似文献   

Effects of silage preservation on astaxanthin forms and fatty acid profiles of processed shrimp (Pandalus borealis) waste     

Alain Guillou  Michel Khalil  Lucien Adambounou 《Aquaculture (Amsterdam, Netherlands)》1995,130(4):351-360

Acid silage of shellfish processing waste has been reported to be a good and economical technique to protect these biomasses from bacterial decomposition. Shrimp (Pandalus borealis) by-products contain some value-added nutrients for the aquaculture industry such as carotenoid pigments (mainly astaxanthin) and n − 3 polyunsaturated fatty acids. The aim of this work was to determine the effect of ensiling shrimp waste during a long period of time (more than 3 months) on some unstable components such as the astaxanthin forms (free, mono- and diesterified) and polyunsaturated fatty acids. Comparisons of astaxanthin forms and the fatty acid profiles were performed on defrosted shrimp waste and on a 14-week-old shrimp waste silage. No significant difference (P ≥ 0.05) in the total lipids extracted from the two forms of shrimp waste was observed. Nevertheless, a small quantity of the red pigment, presumably an astaxanthin portion, was observed to stay firmly bound to the shrimp carapace after the solvent extraction in shrimp waste compared to the full recovery obtained in ensiled shrimp waste. This may explain the significantly (P < 0.05) higher concentration of total astaxanthin (4.57 vs 3.99 mg/g) found in the crude oil extracted from shrimp waste silage. Higher percentages (P < 0.01) of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were found in esterified astaxanthin from shrimp waste silage (43.9% and 45.5%) in comparison with their shrimp waste (24.7% and 20.3%) counterparts. This suggests that EPA and DHA are the principal fatty acids esterified with the portion of astaxanthin linked to chitin in the shrimp carapace. The utilization of shrimp waste silage as a pigmenting component of salmonid feeds is also discussed.  相似文献   

Bacillus thuringiensis efficacy in reducing spruce budworm damage as affected by host tree species     

Alvaro Fuentealba  Éric Bauce  Alain Dupont 《Journal of pest science》2015,88(3):593-603

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反刍动物肝片吸虫病--免疫与疫苗策略     

张为宇  CHAUVIN Alain  黄维义 《广西农业生物科学》2003,22(2):147-152

反刍动物肝片吸虫病在世界范围内对畜牧业造成严重的经济损失，需要研制疫苗进行防制。本文介绍动物肝片吸虫病的保护性免疫应答的表现形式，对保护性免疫应答效应机制和寄生虫免疫逃避机制展开讨论，阐述选择疫苗候选抗原的不同策略，最后探讨研制抗肝片吸虫疫苗所受到的限制因素。  相似文献