Lythrum hyssopifolia (lesser loosestrife) poisoning of sheep in Victoria     

MJ Lancaster  JS Nimmo  C Lenghaus  IJ Gill  RD Crawford  RT Badman  JL Samuel  CJ Werner  C Button  N Kvalheim 《Australian veterinary journal》2009,87(12):476-479

Objective To document an ovine disease attributed to the consumption of Lythrum hyssopifolia (lesser loosestrife). Procedures Historical and histological review of field and experimental cases. Results 1–20% mortality occurred in sheep flocks grazing paddocks where L. hyssopifolia was the predominant green vegetation. Well‐documented disease outbreaks occurred in summer on nine farms across Victoria between 1974 and 2002. Liver damage occurred in all nine outbreaks, with kidney damage in at least eight. Hepatocyte necrosis was usually zonal to midzonal (zone 2) in the liver samples from four farms and periacinar (zone 3) in those from three farms, but some livers showed only single‐cell necrosis. Multinucleate hepatocytes near necrotic areas were a feature in six cases. Proximal tubular epithelium appeared to be the primary renal target and brown granules were often present in renal tubules. Biochemical and histological evidence of liver and kidney damage was obtained from two sheep experimentally pen‐fed harvested L. hyssopifolia. Conclusion Chemicals in L. hyssopifolia are toxic to ovine hepatocytes and renal tubular epithelial cells.  相似文献   

Effects of conjugated linoleic acids (CLA) on tissue response to homeostatic signals and plasma variables associated with lipid metabolism in lactating dairy cows   总被引：1，自引：0，他引：1  

Baumgard LH  Corl BA  Dwyer DA  Bauman DE 《Journal of animal science》2002,80(5):1285-1293

We conducted a series of experiments to evaluate the effects of conjugated linoleic acids (CLA) on lipid metabolism and energy homeostasis in lactating dairy cows. In all experiments, multiparous Holstein cows in mid to late lactation were abomasally infused with CLA for 5 d. The initial study established that trans-10, cis-12 CLA markedly reduced milk fat yield whereas cis-9, trans-11 CLA, the predominant CLA isomer in milk fat, had no effect. Across the three investigations, infusions of the pure trans-10, cis-12 CLA isomer (3.5 to 14.0 g/d) resulted in a 25 to 50% decrease in milk fat yield and this was energetically equivalent to 6 to 11% of net energy intake. Effects were specific for milk fat as there were little or no changes in feed intake and the yield of milk or milk protein. In Exp. 1, infusing trans-10, cis-12 CLA had no effect on circulating plasma concentrations of glucose, insulin, or leptin. Basal NEFA concentrations were also unaffected, but lipolytic response to an epinephrine challenge was reduced (33%) when cows received trans-10, cis-12 CLA; this minor change in lipolytic response would be consistent with the slightly more positive net energy balance when cows received trans-10, cis-12 CLA. In Exp. 2, infusing differing amounts of trans-10, cis-12 CLA had only minor effects on basal NEFA concentrations, but again cows receiving trans-10, cis-12 CLA tended to have reduced (24%) lipolytic response to trans-10, cis-12 CLA compared to the control period. In Exp. 3, infusing trans-10, cis-12 CLA had no effect on basal glucose concentrations or glucose response to an insulin challenge. The fractional rate of glucose clearance in response to insulin was also not altered by treatment. In summary, the effects of trans-10, cis-12 CLA in lactating dairy cows appear to be specific for the mammary gland, resulting in reduced milk fat synthesis; adipose tissue response to a homeostatic signal regulating lipolysis (epinephrine), whole-body response to a homeostatic signal regulating glucose homeostasis (insulin), and plasma variables associated with lipid metabolism and energy homeostasis were relatively unaffected by treatment with trans-10, cis-12 CLA.  相似文献   

Help and containment     

Dwyer E 《Science (New York, N.Y.)》1994,264(5161):1015-1016

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Direct climate effects are more influential than functional composition in determining future gross primary productivity     

McCarthy  James K.  Dwyer  John M.  Mokany  Karel 《Landscape Ecology》2020,35(4):969-984

Landscape Ecology - Most future predictions of forest diversity and composition assume species will shift instantaneously. However, evidence suggests there will be considerable inertia between...  相似文献   

Characterisation of Pasteurella multocida isolated from fowl cholera outbreaks on turkey farms     

PJ BLACKALL  JL PAHOFF  D MARKS†  N FEGAN  CJ MORROW‡ 《Australian veterinary journal》1995,72(4):135-138

SUMMARY: Biochemical profiles, restriction endonuclease analysis (REA) and ribotyping were used to investigate Pasteurella multocida isolates from outbreaks of fowl cholera on 7 turkey farms in New South Wales. While only a single isolate was available from 5 of the farms, multiple isolates, 4 and 12 respectively, were available from the other 2 farms. The available field evidence suggested that 8 outbreaks had occurred with one farm suffering 2 outbreaks. The isolates obtained were all confirmed as Pasteurella multocida . Biochemical profiles allocated the isolates to 4 groups, 3 being variants of P multocida subsp multocida and the fourth being P multocida subsp septica . REA performed with Hpall established 7 groups. Ribotyping using the Hpall digests probed with the 16S rRNA operon of Haemophilus paragallinarum recognised the same 7 groups as REA. Unlike the biochemical profiles, both REA and ribotyping provided a fine subdivision that identified outbreaks as either related or unrelated. The REA and ribotyping patterns as well as biochemical profiles were stable for all isolates from the outbreaks in which multiple isolates were obtained from either the same bird or from different birds. REA and ribotyping were found to be superior to biotyping methods for the investigation of fowl cholera outbreaks.  相似文献   

Computational design of a biologically active enzyme     

Dwyer MA  Looger LL  Hellinga HW 《Science (New York, N.Y.)》2004,304(5679):1967-1971

Rational design of enzymes is a stringent test of our understanding of protein chemistry and has numerous potential applications. Here, we present and experimentally validate the computational design of enzyme activity in proteins of known structure. We have predicted mutations that introduce triose phosphate isomerase activity into ribose-binding protein, a receptor that normally lacks enzyme activity. The resulting designs contain 18 to 22 mutations, exhibit 10(5)- to 10(6)-fold rate enhancements over the uncatalyzed reaction, and are biologically active, in that they support the growth of Escherichia coli under gluconeogenic conditions. The inherent generality of the design method suggests that many enzymes can be designed by this approach.  相似文献   

An atomic-level view of melting using femtosecond electron diffraction     

Siwick BJ  Dwyer JR  Jordan RE  Miller RJ 《Science (New York, N.Y.)》2003,302(5649):1382-1385

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A comparison of the pathogenicity of two strains of hog cholera virus: 2. Virological studies     

S. KAMOLSIRIPRICHAIPORN  CJ MORRISSY  HA WESTBURY 《Australian veterinary journal》1992,69(10):245-248

Quantitative and qualitative differences were demonstrated in the amount of virus in a range of tissues from pigs infected with either the Weybridge or New South Wales (NSW) strains of hog cholera (HC) virus. The titre of the Weybridge strain in samples, as assessed by either virus titration in cell culture or by the density of specific fluorescing cells in tissue sections, was higher than that for the NSW strain. This correlated with the greater severity of the clinico-pathological syndrome induced by the Weybridge strain. The implications of the differences in the virus content of tissues in the diagnosis of HC is discussed as is the use of monoclonal antibodies to differentiate HC and bovine virus diarrhoea viruses.  相似文献   

Efficacy of erythromycin compared with penicillin/streptomycin for the treatment of virulent footrot in sheep   总被引：2，自引：0，他引：2  

JK WEBB WARE  CJ SCRIVENER  AL VIZARD 《Australian veterinary journal》1994,71(3):88-89

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Effect of storage of smears on the staining of ram spermatozoa by eosin or trypan blue     

P. SUTTIYOTIN  CJ THWAITES 《Australian veterinary journal》1994,71(3):87-87

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