Analysis and management of resistance to chemotherapeutants in salmon lice,Lepeophtheirus salmonis (Copepoda: Caligidae)     

Denholm I  Devine GJ  Horsberg TE  Sevatdal S  Fallang A  Nolan DV  Powell R 《Pest management science》2002,58(6):528-536

In Northern Europe and Canada, the salmon louse, Lepeophtheirus salmonis (Kr?yer), seriously affects the marine phase of salmon production. Although the problem is long-standing, the development of sustainable methods of pest management has been unable to keep pace with the intensification of production, leading to large-scale reliance on very few chemotherapeutants. This runs the risk of selecting for genetically determined resistance in target organisms. There are many examples of similar evolutionary adaptations in arthropod pests of arable crops, livestock and human health. Several hundred pest species are now documented as being resistant to one or more chemical classes of insecticides and acaricides. Many of these compounds are identical or closely related to ones currently employed against salmon lice. It is, therefore, opportune to consider what lessons have been learnt from contending with resistance in terrestrial organisms, the implications for sustainable use of chemotherapeutants in aquaculture, and the potential for developing effective resistance management strategies. An EU-funded project named SEARCH (QLK2-CT-2000-00809) has been initiated to explore in more detail the diagnosis, incidence, dynamics and management of resistance to chemotherapeutants in L salmonis.  相似文献   

Progressive tetraparesis and laryngeal paralysis in a young Rottweiler with neuronal vacuolation and axonal degeneration: an Australian case     

CE EGER  CRR HUXTABLE  ZC CHESTER  BA SUMMERS 《Australian veterinary journal》1998,76(11):733-737

A 5-month-old female Rottweiler dog was diagnosed to have a neurodegenerative disease that has been recently report ed in Rottweilers from North America and Europe. The dog was presented with progressive signs of ataxia, tetraparesis and inspiratory stridor. The clinical investigation included analysis of CSF, radiography, myelography and electrophysiolog-ical testing. No evidence of vertebral malformation or inflammatory CNS disease was identified. Bilateral laryngeal paraly sis was identified in the lightly anaesthetised dog. Electromyography showed abnormal spontaneous activity from the intrin sic musculature of the larynx. At necropsy there were no gross abnormalities of the nervous system but there was atrophy of the dorsal cricoarytenoid muscles of the larynx. There were widespread histological abnormalities throughout the ner vous system including neuronal vacuolation, spongiform changes in the neuropil and axonal degeneration which was most prominent in the spinal cord. These clinical and pathological findings are consistent with the diagnosis of a new neurode-generative disease reported from North America and Europe. This diagnosis is of particular significance in Australia where transmissible spongiform encephalopathies have not been identified.  相似文献   

Changes in Glucocorticoid Receptor Levels of Bovine Lymphocyte and Neutrophil during Estrous Cycle     

PE Martínez  MTP Lopes  MS Martins  AP Marques Jr  CE Salas 《Reproduction in domestic animals》1998,33(2):61-66

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Why are there not more herbicide-tolerant crops?     

Devine MD 《Pest management science》2005,61(3):312-317

Herbicide-tolerant (HT) varieties of corn, soybean, canola (oilseed rape) and cotton have been grown since the mid-1990s, and have been widely adopted by farmers in several countries. HT genes have been inserted into or selected for in many other species, including almost all major crop species in the world and many minor crops and ornamental species. In some cases this has been done specifically to introduce the HT trait, whereas in others the HT gene has been used as a selectable marker (eg the bar gene, conferring glufosinate-ammonium tolerance). However, in very few cases have the HT crops generated been commercialized, despite the weed-control advantages that many such crops would offer. There are several reasons for this, including the high research and development costs associated with developing the new HT crop cultivars, the high cost of obtaining regulatory clearance for the HT crops or products derived from them, international trade issues relating to genetically modified crops, and issues surrounding the expanded herbicide registration for the new use and the potential impact of this on the existing registration status of the herbicide. New HT crops are unlikely to be developed unless they offer a sufficiently large advantage to farmers and a substantial assured market to justify the associated development and regulatory costs.  相似文献   

Cranial tibial thrust: a primary force in the canine stifle   总被引：5，自引：0，他引：5  

B Slocum  T Devine 《Journal of the American Veterinary Medical Association》1983,183(4):456-459

A cranially directed force identified within the canine stifle joint was termed cranial tibial thrust. It was generated during weight bearing by tibial compression, of which the tarsal tendon of the biceps femoris is a major contributor, and by the slope of the tibial plateau, found to have a mean cranially directed inclination of 22.6 degrees. This force may be an important factor in cranial cruciate ligament rupture and in generation of cranial drawer sign.  相似文献   

EFFECTS OF INDUCED CRYPTORCHIDISM IN BULLS     

J. J. Bass B.Sc.  Ph.D.  A. J. Peterson B.Sc.  Ph.D.  C. E. Devine B.Sc.  Ph.D. 《Australian veterinary journal》1976,52(11):517-518

Ninety bull calves were made cryptorchid by forcing the testes into the abdominal cavity and ablating the scrotum with elastrator rings. Normal spermatogenesis was seen following histological examination of some of the testes approximately 17 months after the operation. No effect on bull behaviour was noted in the cryptorchids although plasma testosterone levels were lower than those reported for bulls. It is possible that this method may leave some of the cryptorchids fertile.  相似文献   

Altered target sites as a mechanism of herbicide resistance   总被引：4，自引：0，他引：4  

Malcolm D. Devine  Amit Shukla   《Crop Protection》2000,19(8-10):881-889

Over 200 distinct herbicide resistant weed biotypes have evolved worldwide. In most of these, resistance is conferred by an altered target site, i.e. a modified target protein with reduced affinity for the herbicide(s) in question. This has been documented for herbicides that target most major known sites of action, including those that inhibit photosynthetic electron transfer at photosystem II, acetyl-CoA carboxylase, acetolactate synthase, and tubulin polymerization. Patterns of cross-resistance to structurally similar herbicides and those from other chemical classes that target the same site vary, depending on the mutation and its effect on protein steric and electronic properties. Mechanisms of target site-based herbicide resistance are reviewed, with emphasis on the biochemical and molecular basis for resistance.  相似文献   

Use of resistant ACCase mutants to screen for novel inhibitors against resistant and susceptible forms of ACCase from grass weeds     

Shukla A  Nycholat C  Subramanian MV  Anderson RJ  Devine MD 《Journal of agricultural and food chemistry》2004,52(16):5144-5150

The aryloxyphenoxypropionic acid (AOPP) and cyclohexanedione (CHD) herbicides inhibit the first committed enzyme in fatty acid biosynthesis, acetyl CoA carboxylase (ACCase). The frequent use of AOPP and CHD herbicides has resulted in the development of resistance to these herbicides in many grass weed species. New herbicides that inhibit both the susceptible and resistant forms of ACCase in grass weeds would have obvious commercial appeal. In the present study, an attempt was made to identify molecules that target both the herbicide-sensitive and -resistant forms of ACCase. Seven experimental compounds, either CHD-like or AOPP-CHD hybrids, were synthesized and assayed against previously characterized susceptible and resistant forms of ACCase. All seven compounds inhibited ACCase from sensitive biotypes of Setaria viridis and Eleusine indica (I50 values from 6.4 to >100 microM) but were not particularly potent compared to some commercialized herbicides (I50 values of 0.08-5.6 microM). In almost all cases, the I50 values for each compound assayed against the resistant ACCases were higher than those against the corresponding sensitive ACCase, indicating reduced binding to the resistant ACCases. One compound, a CHD analogue, was almost equally effective against the resistant and susceptible ACCases, although it was not a very potent ACCase inhibitor per se (I50 of 51 and 76 microM against susceptible ACCase from S. viridis and E. indica, respectively). The AOPP-CHD hybrid molecules also inhibited some of the resistant ACCases, with I50 values ranging from 6.4 to 50 microM. These compounds may be good leads for developing ACCase inhibitors that target a wider range of ACCase isoforms, including those found in AOPP- and CHD-resistant weed biotypes.  相似文献   

Immune response to avian reovirus in chickens and protection against experimental infection     

J. MEANGER  R. WICKRAMASINGHE  CE ENRIQUEZ  GE WILCOX 《Australian veterinary journal》1997,75(6):428-432

Objectives To assess the efficacy of the vaccination procedure and the effect of the transfer of maternal antibodies to progeny chickens on reovirus pathogenicity.
Design To vaccinate chickens and challenge progeny chickens with high doses of homologous and heterologous viruses.
Procedure High doses of reovirus strains RAM-1, 1091 and 724 were used to induce tenosynovitis lesions. High doses were produced by concentration of viruses grown in cell culture. Then similar doses of viruses were used to challenge immunised chickens progeny.
Result Vaccination of breeding hens with the RAM-1 strain of avian reovirus, which resulted in the passive transfer of neutralising antibody to progeny chickens, completely prevented the development of tenosynovitis in 80% of progeny chickens infected with the homologous virus. Even though multiple injection of hens resulted in broadening of the normal type-specificity of the neutralising antibody response against heterologous serotypes of avian reovirus, only marginal protection against strains of two heterologous serotypes of avian reovirus was obtained.
Conclusions A model for assessing the efficacy of vaccination against avian reovirus strains on clinical signs such as tenosynovitis was developed that overcome the normal low virulence of Australian strains of avian reovirus. Breeding hens can be immunised with Australian strain of avian reovirus with passive transfer of antibody via the yolk to the progeny chickens. Although the neutralising antibody response to three injections of inactivated virus decreased the specificity of the neutralising antibody response against antigenically heterologous strains of avian reovirus, the protective immunity appeared to retain type-specificity.  相似文献   

Evaluation of the Brix refractometer as an on‐farm tool for the detection of passive transfer of immunity in dairy calves          下载免费PDF全文

JB Thornhill  GL Krebs  CE Petzel 《Australian veterinary journal》2015,93(1-2):26-30

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