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71.
The presence of virulent Newcastle disease virus (NDV) since the 1993-94 epidemic in southern Africa holds major implications for the export of ostrich products from this region. A challenge experiment with this field strain was conducted in open-air feedlot facilities under strict biosecurity measures. The experiment was designed to follow vaccination and preslaughter quarantine regulations currently enforced in South African export ostrich facilities in order to determine the viremia period and immune response under these specific circumstances. One hundred forty-three slaughter ostriches were allocated into three test groups, according to the time period between pretrial vaccination and challenge (1-2 mo, 2-4 mo, 4-6 mo), and an unchallenged control group. All birds in the test groups were challenged by oral, tracheal, and ocular routes with a field isolate of NDV. They were slaughtered over the next 4 wk on nine separate occasions and bled on 12 occasions. Virus isolation was attempted from seven sets of pooled samples from each bird to determine the viremia period and the serum antibody concentrations were measured by hemagglutination inhibition (HI) and enzyme-linked immunosorbent assay (ELISA) methods to establish an immune response curve. NDV could be back-isolated only up to day 9 postinfection and from only six ostriches with poor immune response titers and corresponding to a rise in antibody levels above an indirect ELISA optical density reading of 0.33. Virus could be recovered only from brain and respiratory tract tissue. The HI test was less sensitive than the ELISA. Immune response curves did not differ significantly between the groups and peaked on day 14 post-infection. From these data, ELISA titers would appear to be a good indicator of the probability that an ostrich will be clinically infected after velogenic NDV challenge. These results also suggest that the current vaccination schedule enforced by the South African Veterinary Authorities results in protective immunity in up to 95% of slaughter ostriches from export approved facilities. The standard 30-day preslaughter quarantine period introduced as part of Crimean-Congo hemorrhagic fever virus control measures also appears sufficient to encompass the determined NDV viremia period of 9-11 days in slaughter ostriches. 相似文献
72.
Ludovic Bouré DMV MSc Diplomate ECVS Diplomate ACVS Marcel Marcoux DMV MSc Sheila Laverty MVB Diplomate ACVS Diplomate ECVS Olivier M. Lepage DMV PhD Diplomate ECVS 《Veterinary surgery : VS》1999,28(4):226-232
OBJECTIVE: To develop a technique for arthroscopic excision of apical sesamoid fracture fragments using electrocautery probes. ANIMALS OR SAMPLE POPULATION: A total of 18 Standardbred horses. METHODS: Arthroscopic removal of apical sesamoid fracture fragments using both hook and loop electrocautery probes was performed on 18 Standardbred horses. The fracture fragments were approached using either an ipsilateral (3) or contralateral (15) arthroscopic triangulation technique. Distension of the metacarpo- (metatarso)-phalangeal joints was achieved using a 1.5% glycine solution. Under arthroscopic guidance, both the suspensory and intersesamoidean ligament attachments to the abaxial and the axial margins of the apical fragment were transected using a hook electrocautery probe. Subsequently, the palmar (plantar) soft tissue attachments to the apical fragment were transected with a loop electrocautery probe. Once freed of soft tissue attachments, the apical fragment was removed with Ferris-Smith intervertebral disc rongeur. The arthroscopic portals were closed in a routine manner. RESULTS: Horse ages ranged from 2 to 8 years (median, 2.5 years). Eighteen apical sesamoid fracture fragments were removed from the left (8) and right (8) hind limbs and the left (1) and right (1) forelimbs. Apical fragments occured in 15 lateral and 3 medial proximal sesamoid bones. No major complications occurred during or after surgery. The electrocautery probes permitted an easy and precise dissection of all soft tissue attachments to the apical sesamoid fracture fragments in all horses. Follow-up time was 7 to 44 months (median, 26 months); 10 of 14 horses returned to racing. Seven of nine horses that raced before surgery raced again and three of five that had not raced before surgery, raced afterwards. CONCLUSION: Arthroscopic excision of apical sesamoid fracture fragments can be accomplished arthroscopically using electrocautery probes. CLINICAL RELEVANCE: Arthroscopic electrosurgery is an efficient and safe alternative for intra-articular dissection in horses. 相似文献
73.
Laser therapy is used in many countries, including South Africa, for the treatment of skin wounds. Low level galium aluminium arsenide (GaAlAs) laser was administered to full thickness skin wounds (3 x 3 cm) induced surgically on the dorsal aspect of the metacarpophalangeal joints of 6 crossbred horses in a randomised, blind, controlled study. Treated wounds that received a daily laser dosage of 2 J/cm2 were compared with nontreated control wounds on the opposite leg. There were no wound complications. Both groups of wounds were cleaned daily using tap water. Wound contraction and epithelialisation were evaluated using photoplanimetry. There were no significant differences in wound contraction or epithelialisation between the laser treated and the control wounds. It was therefore concluded that laser therapy had no clinically significant effect on second intention wound healing in this study. 相似文献
74.
Mahmoud A. O. Dawood Shunsuke Koshio Manabu Ishikawa Mabrouk El-Sabagh Saichiro Yokoyama Wei-Long Wang Zhang Yukun Adissin Olivier 《Fish physiology and biochemistry》2017,43(1):179-192
Environmental stressors caused by inadequate aquaculture management strategies suppress the immune response of fish and make them more susceptible to diseases. Therefore, efforts have been made to relieve stress in fish by using various functional feed additives in the diet, including probiotics. The present work evaluates the effects of Lactobacillus rhamnosus (LR) on physiological stress response, blood chemistry and mucus secretion of red sea bream (Pagrus major) under low salinity stress. Fish were fed four diets supplemented with LR at [0 (LR0), 1 × 102 (LR1), 1 × 104 (LR2) and 1 × 106 (LR3) cells g?1] for 56 days. Before stress, blood cortisol, urea nitrogen (BUN) and total bilirubin (T-BIL) showed no significant difference (P > 0.05), whereas plasma glucose and triglyceride (TG) of fish-fed LR2 and LR3 diets were significantly lower (P < 0.05) than those of the other groups. Plasma total cholesterol (T-CHO) of fish-fed LR3 diet was significantly (P < 0.05) lower than that of the other groups. Furthermore, total plasma protein, mucus myeloperoxidase activity and the amount of mucus secretion were significantly enhanced in LR-supplemented groups when compared with the control group (P < 0.05). After the application of the low salinity stress test, plasma cortisol, glucose, T-CHO and TG contents in all groups showed an increased trend significantly (P < 0.01) compared to the fish before the stress challenge. However, plasma total protein and the amount of secreted mucus showed a decreased trend in all groups. On the other hand, BUN, T-BIL and mucus myeloperoxidase activity showed no significant difference after exposure to the low salinity stress (P > 0.05). In addition, the fish that received LR-supplemented diets showed significantly higher tolerance against low salinity stress than the fish-fed LR-free diet (P < 0.05). The physiological status and the detected immune responses, including total plasma protein and mucus myeloperoxidase activity in red sea bream, will provide a more comprehensive outlook of the effects of probiotics to relieve stress in fish. 相似文献
75.
Luc Doyen Christophe Béné Michel Bertignac Fabian Blanchard Abdoul Ahad Cissé Catherine Dichmont Sophie Gourguet Olivier Guyader Pierre‐Yves Hardy Sarah Jennings Lorne Richard Little Claire Macher David Jonathan Mills Ahmed Noussair Sean Pascoe Jean‐Christophe Pereau Nicolas Sanz Anne‐Maree Schwarz Tony Smith Olivier Thébaud 《Fish and Fisheries》2017,18(6):1056-1072
Reconciling food security, economic development and biodiversity conservation is a key challenge, especially in the face of the demographic transition characterizing many countries in the world. Fisheries and marine ecosystems constitute a difficult application of this bio‐economic challenge. Many experts and scientists advocate an ecosystem approach to manage marine socio‐ecosystems for their sustainability and resilience. However, the ways by which to operationalize ecosystem‐based fisheries management (EBFM) remain poorly specified. We propose a specific methodological framework—viability modelling—to do so. We show how viability modelling can be applied using four contrasted case‐studies: two small‐scale fisheries in South America and Pacific and two larger‐scale fisheries in Europe and Australia. The four fisheries are analysed using the same modelling framework, structured around a set of common methods, indicators and scenarios. The calibrated models are dynamic, multispecies and multifleet and account for various sources of uncertainty. A multicriteria evaluation is used to assess the scenarios’ outcomes over a long time horizon with different constraints based on ecological, social and economic reference points. Results show to what extent the bio‐economic and ecosystem risks associated with the adoption of status quo strategies are relatively high and challenge the implementation of EBFM. In contrast, strategies called ecoviability or co‐viability strategies, that aim at satisfying the viability constraints, reduce significantly these ecological and economic risks and promote EBFM. The gains associated with those ecoviability strategies, however, decrease with the intensity of regulations imposed on these fisheries. 相似文献
76.
Fishes are both extremely diverse and morphologically disparate. Part of this disparity can be observed in the numerous possible fin configurations that may differ in terms of the number of fins as well as fin shapes, sizes and relative positions on the body. Here, we thoroughly review the major patterns of disparity in fin configurations for each major group of fishes and discuss how median and paired fin homologies have been interpreted over time. When taking into account the entire span of fish diversity, including both extant and fossil taxa, the disparity in fin morphologies greatly complicates inferring homologies for individual fins. Given the phylogenetic scope of this review, structural and topological criteria appear to be the most useful indicators of fin identity. We further suggest that it may be advantageous to consider some of these fin homologies as nested within the larger framework of homologous fin‐forming morphogenetic fields. We also discuss scenarios of appendage evolution and suggest that modularity may have played a key role in appendage disparification. Fin modules re‐expressed within the boundaries of fin‐forming fields could explain how some fins may have evolved numerous times independently in separate lineages (e.g., adipose fin), or how new fins may have evolved over time (e.g., anterior and posterior dorsal fins, pectoral and pelvic fins). We favour an evolutionary scenario whereby median appendages appeared from a unique field of competence first positioned throughout the dorsal and ventral midlines, which was then redeployed laterally leading to paired appendages. 相似文献
77.
Between 1995 and 1997, 278 grape downy mildew (Plasmopara viticola) populations originating from European vineyards were characterised for their sensitivity to cymoxanil in a leaf-disc assay. The sensitivity profile revealed a wide distribution, with minimum inhibitory concentrations (MIC) ranging from 10 to more than 800 mg litre−1. EC50 values ranged from 1 to more than 800 mg litre−1 with an average of 125 mg litre−1. The sensitivity distribution was stable between 1995 and 1997. Surprisingly, populations from Portugal appeared significantly more sensitive than those from France or Italy, which could not be linked to differential cymoxanil usage in these countries. P viticola populations collected outside Europe and never exposed to cymoxanil appeared significantly more sensitive than exposed European populations, with an average EC50 value of 10 mg litre−1. The level of sensitivity of European P viticola populations was relatively unaffected by the number of cymoxanil applications made during a season or by the number of years of cymoxanil use. No link was found between the level of sensitivity in the leaf-disc assay and the level of performance of the cymoxanil mixtures used in the fields where the populations originated. Specific field trials conducted in Italy and Portugal have shown that the performance of cymoxanil-based mixtures remained good even on populations of the grape downy mildew fungus characterised as less sensitive in the leaf-disc assay. While there are no baseline sensitivity data for pre-commercialisation P viticola populations, the results of our study suggest that a shift in sensitivity (12.5-fold) may have occurred in some areas since introduction of cymoxanil on grapes nearly 20 years ago. Because cymoxanil is never used alone, it is difficult to determine whether or not practical resistance is occurring in European vineyards. © 1999 Society of Chemical Industry 相似文献
78.
Nicolas Marinval Pierre Saboural Oualid Haddad Murielle Maire Kevin Bassand Frederic Geinguenaud Nadia Djaker Khadija Ben Akrout Marc Lamy de la Chapelle Romain Robert Olivier Oudar Erwan Guyot Christelle Laguillier-Morizot Angela Sutton Cedric Chauvierre Frederic Chaubet Nathalie Charnaux Hanna Hlawaty 《Marine drugs》2016,14(10)
Herein we investigate the structure/function relationships of fucoidans from Ascophyllum nodosum to analyze their pro-angiogenic effect and cellular uptake in native and glycosaminoglycan-free (GAG-free) human endothelial cells (HUVECs). Fucoidans are marine sulfated polysaccharides, which act as glycosaminoglycans mimetics. We hypothesized that the size and sulfation rate of fucoidans influence their ability to induce pro-angiogenic processes independently of GAGs. We collected two fractions of fucoidans, Low and Medium Molecular Weight Fucoidan (LMWF and MMWF, respectively) by size exclusion chromatography and characterized their composition (sulfate, fucose and uronic acid) by colorimetric measurement and Raman and FT-IR spectroscopy. The high affinities of fractionated fucoidans to heparin binding proteins were confirmed by Surface Plasmon Resonance. We evidenced that LMWF has a higher pro-angiogenic (2D-angiogenesis on Matrigel) and pro-migratory (Boyden chamber) potential on HUVECs, compared to MMWF. Interestingly, in a GAG-free HUVECs model, LMWF kept a pro-angiogenic potential. Finally, to evaluate the association of LMWF-induced biological effects and its cellular uptake, we analyzed by confocal microscopy the GAGs involvement in the internalization of a fluorescent LMWF. The fluorescent LMWF was mainly internalized through HUVEC clathrin-dependent endocytosis in which GAGs were partially involved. In conclusion, a better characterization of the relationships between the fucoidan structure and its pro-angiogenic potential in GAG-free endothelial cells was required to identify an adapted fucoidan to enhance vascular repair in ischemia. 相似文献
79.
Catherine Ky-Dembele Jules Bayala Antoine Kalinganire Fatoumata Tata Traoré Bréhima Koné Alain Olivier 《Southern Forests》2016,78(3):185-192
In the Sahel region, many woody species are used as fodder because of their high nitrogen content, especially during the dry season, in contrast to grasses and crop residues. Unfortunately, this resource is being threatened by regular pruning, increasing livestock browsing and impeding their natural regeneration. Therefore, there is a need to find appropriate regeneration options to sustain fodder production. Thus, a series of vegetative propagation experiments were conducted to identify the most appropriate multiplication methods of some of the species used as fodder. This series included testing the effects of naphthalene acetic acid (NAA) and indole butyric acid (IBA) on rooting ability of stem cuttings of 12 species: Afzelia africana, Balanites aegyptiaca, Bauhinia rufescens, Commiphora africana, Faidherbia albida, Ficus gnaphalocarpa, Guiera senegalensis, Kigelia africana, Pterocarpus erinaceus, Pterocarpus lucens, Pterocarpus santalinoides and Terminalia avicennioides. The series also evaluated the impacts of the size (C. africana) and the age (P. erinaceus) of the cuttings on their rooting success. Pterocarpus santalinoides was revealed to be an easy-to-root species, showing a high percentage of rooted cuttings (up to 88±3%), followed by P. erinaceus, P. lucens and B. aegyptiaca (up to 37±4%, 31±5% and 26±6%, respectively), in contrast to A. africana, cuttings of which did not root at all. The application of NAA and IBA enhanced the number of roots and secondary roots per rooted cutting. Large-diameter cuttings (15–20?mm) of deeply planted C. africana gave the highest percentage of rooted cuttings (78.3±4.4%). Tree pruning improved the rooting capacity of cuttings collected from P. erinaceus with one-month resprouts giving the highest percentage of rooted cuttings (50.0±6.7%). These results indicate that P. santalinoides, C. africana, P. erinaceus, P. lucens and B. aegyptiaca are amenable to vegetative propagation as an alternative to sexual propagation. 相似文献
80.
Oualid Haddad Erwan Guyot Nicolas Marinval Fabien Chevalier Lo?c Maillard Latifa Gadi Christelle Laguillier-Morizot Olivier Oudar Angela Sutton Nathalie Charnaux Hanna Hlawaty 《Marine drugs》2015,13(11):6588-6608
Induction of angiogenesis is a potential treatment for chronic ischemia. Low molecular weight fucoidan (LMWF), the sulfated polysaccharide from brown seaweeds, has been shown to promote revascularization in a rat limb ischemia, increasing angiogenesis in vivo. We investigated the potential role of two heparan sulfate (HS) metabolism enzymes, exostosin-2 (EXT2) and heparanase (HPSE), and of two HS-membrane proteoglycans, syndecan-1 and -4 (SDC-1 and SDC-4), in LMWF induced angiogenesis. Our results showed that LMWF increases human vascular endothelial cell (HUVEC) migration and angiogenesis in vitro. We report that the expression and activity of the HS-degrading HPSE was increased after LMWF treatment. The phenotypic tests of LMWF-treated and EXT2- or HPSE-siRNA-transfected cells indicated that EXT2 or HPSE expression significantly affect the proangiogenic potential of LMWF. In addition, LMWF increased SDC-1, but decreased SDC-4 expressions. The effect of LMWF depends on SDC-4 expression. Silencing EXT2 or HPSE leads to an increased expression of SDC-4, providing the evidence that EXT2 and HPSE regulate the SDC-4 expression. Altogether, these data indicate that EXT2, HPSE, and SDC-4 are involved in the proangiogenic effects of LMWF, suggesting that the HS metabolism changes linked to LMWF-induced angiogenesis offer the opportunity for new therapeutic strategies of ischemic diseases. 相似文献