Branchial structure and hydromineral equilibrium in juvenile turbot (S<Emphasis Type="Italic">cophthalmus maximus)</Emphasis> exposed to heavy fuel oil

This study is an attempt to go further in the comprehension of the effects of heavy fuel oil in the context of an accidental oil spill at sea. It focuses on the link between morphological and functional impacts of realistic doses of the dissolved fraction of a heavy fuel oil on fish gills. Juvenile turbot, Scophthalmus maximus were exposed to the dissolved fraction of a heavy fuel oil for 5 days and then placed 30 days in clean sea water for recovery. During the contamination period, the concentration of the 16 US EPA priority poly-aromatic hydrocarbons showed small variations around a mean value of 321.0 ± 9.1 ng l⁻¹ (mean ± SEM). The contamination induced a 64% increase in hepatic cytochrome P 450 1A (Western blot analysis). Osmolality, [Na⁺] and [Cl⁻] rapidly and significantly increased (by 14, 23 and 28% respectively) and slowly decreased to normal levels during the recovery period. At the same time, branchial histology showed decreases in the number of mucocytes (by 30%) and of chloride cells (by 95%) in the interlamellar epithelium. Therefore, it is suggested that the osmotic imbalance observed after the 5 days of exposure to the dissolved fraction of the heavy fuel oil is the consequence of the structural alteration of the gills i.e, the strong reduction of ionocyte numbers.     

Evolution of supergene families associated with insecticide resistance

The emergence of insecticide resistance in the mosquito poses a serious threat to the efficacy of many malaria control programs. We have searched the Anopheles gambiae genome for members of the three major enzyme families- the carboxylesterases, glutathione transferases, and cytochrome P450s-that are primarily responsible for metabolic resistance to insecticides. A comparative genomic analysis with Drosophila melanogaster reveals that a considerable expansion of these supergene families has occurred in the mosquito. Low gene orthology and little chromosomal synteny paradoxically contrast the easily identified orthologous groups of genes presumably seeded by common ancestors. In A. gambiae, the independent expansion of paralogous genes is mainly a consequence of the formation of clusters among locally duplicated genes. These expansions may reflect the functional diversification of supergene families consistent with major differences in the life history and ecology of these organisms. These data provide a basis for identifying the resistance-associated enzymes within these families. This will enable the resistance status of mosquitoes, flies, and possibly other holometabolous insects to be monitored. The analyses also provide the means for identifying previously unknown molecules involved in fundamental biological processes such as development.     

Feeding value of hays of tropical forage legumes in pigs: Vigna unguiculata,Psophocarpus scandens,Pueraria phaseoloides and Stylosanthes guianensis

The effects of four tropical forage legume hays (Vigna unguiculata, Psophocarpus scandens, Pueraria phaseoloides and Stylosanthes guianensis) on voluntary feed intake (VFI) and their nutritive value were studied in growing pigs using a corn-soybean meal-based diet containing varying proportions of forage legume hays (0, 10, 20 and 40 % or 0, 12.5 and 25 % for VFI and nutritive value determination, respectively). There was no difference in VFI between species (P?>?0.20), but a linear response to forage inclusion level (P?V. unguiculata, where the response was quadratic (P?=?0.01). All four forage species linearly decreased the total tract apparent digestibility (TTAD) from 0.76 to 0.61, 0.80 to 0.68, 0.54 to 0.40 and 0.58 to 0.31 except for S. guianensis (0.44) for DM, N, NDF and N retention, respectively. Differences in digestibility (P?S. guianensis, in which N retention remained quite high (0.44) at the highest inclusion level (25 %). P. phaseoloides hay should be avoided in pigs as it combines the lowest VFI with the lowest nutrient digestibility.     

Pharmaceutical and nutraceutical management of canine osteoarthritis: present and future perspectives

Osteoarthritis (OA) is one of the most common chronic musculoskeletal diseases and causes of lameness in the dogs. The osteoarthritic disease process involves the entire synovial joint, encompassing the synovium, cartilage and underlying bone. Joint failure results from an abnormal mechanical strain causing damage to normal tissue or failure of pathologically impaired articular cartilage and bone under the influence of normal physiological strain or a combination of both. In both cases, the end point is cartilage loss and joint impairment. Osteoarthritic chondrocytes show an altered phenotype characterised by an excess production of catabolic factors, including metalloproteinases and reactive oxygen species. These factors constitute potential therapeutic targets and some new drugs and nutraceuticals have been proposed to promote the return to homeostasis. Until now, the therapeutic management of OA in dogs has been dominated by nonsteroidal anti-inflammatory drugs, but some new compounds, including diacerhein, with potential structure-modifying effects, are already used to treat OA in humans and could be helpful to manage OA in the dog. In addition, novel nutraceuticals, such as avocado/soybean unsaponifiable substances, have shown symptomatic effects in knee OA in humans, and could offer an alternative to prevent OA progression. This paper provides an overview of recent discoveries in the pathophysiology and in the therapeutic management of osteoarthritis in dogs.     

Direct impacts of recent climate warming on insect populations

Effects of recent climate change have already been detected in many species, and, in particular, in insects. The present paper reviews the key impacts of global warming on insect development and dispersal. The effects of climate change appear to be much more complex than a simple linear response to an average increase in temperature. They can differ between seasons and bioclimatic regions. Earlier flight periods, enhanced winter survival and acceleration of development rates are the major insect responses. Differential response of insects and hosts to warming up might also lead to disruption of their phenological synchrony, but adaptive genetic processes are likely to quickly restore this synchrony. In a number of cases, warming results in removing or relocating the barriers that limit present species' ranges. It is also likely to facilitate the establishment and spread of invasive alien species. Finally, knowledge gaps are identified and future research interests are suggested.     

Voluntary acceptance and consumption of two oral ciclosporin formulations in dogs: two randomised,controlled studies

Background

Atopic dermatitis (AD) is the most common canine allergic skin disease and can significantly affect the quality of life of affected dogs. Treating canine AD with ciclosporin has been a subject of great interest in recent years. Many studies have provided substantial evidence of ciclosporin efficacy and safety in canine AD management, and for several years ciclosporin has been recognised as a major component of canine AD multimodal therapy. As a chronic condition, canine AD requires life-long medical management and treatment success relies in large part on product ease of administration. Two studies were conducted to assess the comparative voluntary acceptance and consumption of Cyclavance® (Virbac), a new oral liquid formulation of ciclosporin, and Atopica® (Novartis) either added to a small quantity of kibbles (study 1) or administered directly into the dog’s mouth (study 2).

Results

Over the course of the two studies 70 dogs assessed each of the ciclosporin formulations and 320 individual tests were performed for each tested product. Immediate prehension (in less than 2 seconds) occurred significantly more often with Cyclavance® (90.6% of the tests) than with Atopica® (14.4% of the tests) when products were mixed with 30 grams of dry food (p < 0.001). Moreover, Cyclavance® was significantly more often easily accepted than Atopica® (99.3% vs 27.1% of the tests, respectively) when products were administered directly into the dogs’ mouth (p < 0.0001). Cyclavance® was also more often totally consumed (98.3% of the tests) than Atopica® (2.2% of the tests) when mixed with a small amount of food (p < 0.001). However, both products were totally consumed once administered directly into the dogs’ mouth.

Conclusions

By facilitating cicloporin administration and consumption, Cyclavance® liquid formulation offers an interesting alternative to capsules that may improve dosing compliance and therefore the ability to benefit from the therapeutic effects in the long-term treatment of canine AD.     

What attracts elk onto cattle pasture? Implications for inter-species disease transmission

In Southwest Alberta, beef cattle and wild elk (Cervus elaphus) have similar habitat preferences. Understanding their inter-species contact structure is important for assessing the risk of pathogen transmission between them. These spatio-temporal patterns of interactions are shaped, in part, by range management and environmental factors affecting elk distribution. In this study, resource selection modeling was used to identify factors influencing elk presence on cattle pasture and elk selection of foraging patches; furthermore, consequences for inter-species disease transmission were discussed.     

Functional investigation of a QTL affecting resistance to Haemonchus contortus in sheep

This study reports a functional characterization of a limited segment (QTL) of sheep chromosome 12 associated with resistance to the abomasal nematode Haemonchus contortus. The first objective was to validate the identified QTL through the comparison of genetically susceptible (N) and resistant (R) sheep produced from Martinik × Romane back-cross sheep. The R and N genotype groups were then experimentally infected with 10 000 H. contortus larvae and measured for FEC (every three days from 18 to 30 days post-challenge), haematocrit, worm burden and fertility. Significant differences in FEC and haematocrit drop were found between R and N sheep. In addition, the female worms recovered from R sheep were less fecund. The second step of the characterization was to investigate functional mechanisms associated with the QTL, thanks to a gene expression analysis performed on the abomasal mucosa and the abomasal lymph node. The gene expression level of a candidate gene lying within the QTL region (PAPP-A2) was measured. In addition, putative interactions between the chromosome segment under study and the top ten differentially expressed genes between resistant MBB and susceptible RMN sheep highlighted in a previous microarray experiment were investigated. We found an induction of Th-2 related cytokine genes expression in the abomasal mucosa of R sheep. Down-regulation of the PAPP-A2 gene expression was observed between naïve and challenged sheep although no differential expression was recorded between challenged R and N sheep. The genotyping of this limited region should contribute to the ability to predict the intrinsic resistance level of sheep.     

Are the long‐term fluctuations in Atlantic bluefin tuna (Thunnus thynnus) population related to environmental changes?

We tested whether synchronous, long‐term fluctuations in Atlantic bluefin tuna (Thunnus thynnus) trap catches, collected from the ancestral Mediterranean and Atlantic trap fishery, might be related to large‐scale environmental change. Nine time series of trap catches of more than 80 yr long were compared with long time series of three preselected environmental variables, i.e. the North Atlantic Oscillation (NAO), the Length of the Day Index (LOD, a proxy of the atmospheric circulation index) and the temperature. Spectral analyses of trap catches, LOD and temperature displayed similar spectra with peaks at low frequencies, whereas those of the NAO exhibited a broad band spectrum. Regression analyses and tests of correlation did not reveal any clear relationship between trap catches on the one hand and NAO and LOD on the other hand. In contrast, long‐term fluctuations in trap catches appear to be closely and negatively related to long‐term trends in temperature. Underlying processes that could explain such a relationship are discussed, with special focus on changes in migration patterns of the Atlantic bluefin tuna.