Validation study of gas chromatographic determination of pentachlorophenol in animal liver

A validation study was conducted of a gas chromatographic procedure for the determination of pentachlorophenol (PCP) in chicken, pork, and beef liver. Five analysts representing 5 laboratories analyzed randomly numbered blind duplicates at 3 fortified tissue concentrations and one incurred tissue on 2 consecutive days. The PCP concentrations ranged from approximately 40 to 400 parts per billion (ppb). All data were reported to 3 significant figures in ppb. The coefficients of variation for repeatability were between 2.8 and 8.5%, except for the beef liver, at a mean value of 80 ppb PCP, where the CV was 11.3%. The CVs for reproducibility were in the range of 9.7-16.5% with little significant difference by species. The CV asymptotically approached 10% as the PCP level increased.     

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

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.     

Assessment of Pierce's disease susceptibility in Vitis vinifera cultivars with different pedigrees

Pierce's disease (PD) of grapevine is caused by the bacterium Xylella fastidiosa. In this study, an integrated approach was applied to assess PD susceptibility among different Vitis vinifera cultivars that incorporated disease severity, bacterial pathogen abundance and loss of stem xylem hydraulic conductivity. It was hypothesized that levels of PD susceptibility in V. vinifera can be attributed in part to the host anatomical features that are shaped by its pedigree background. Two popular wine grape cultivars were initially selected from the occidentalis group, Merlot and Cabernet Sauvignon, and one from the orientalis group, Thompson Seedless. The more recently bred table grape cultivar Scarlet Royal, that has mixed pedigree parentage, was also included. PD susceptibility was compared to the known PD resistant b43-17 V. arizonica/candicans wild grape species from North America. The data indicated that Thompson Seedless was ranked as the most susceptible to PD because it significantly exhibited the most severe disease symptoms at 12 weeks post-inoculation and hosted the highest X. fastidiosa titre of the cultivars, and lost over 90% of its stem hydraulic conductivity. In contrast, the other three cultivars displayed less susceptibility to PD. The way in which the xylem anatomy could impact PD susceptibility in V. vinifera cultivars is discussed, together with how grape pedigrees and their cognate centre of domestication may have influenced xylem anatomical features. This work provides a reference framework to further test the hypothesis that V. vinifera cultivars with wide xylem vessels may be more prone to PD decline.     

Paleolimnology of late quaternary deposits: seibold site, north dakota

A unique late Quaternary lacustrine deposit has been discovered recently on the Missouri Coteau of North Dakota. A diverse, extremely well-preserved biota of more than 160 species has been recovered primarily from an organic mud deposited about 9500 years before the present. The lacustrine body shallowed gradually as the climate became drier.     

Lythrum hyssopifolia (lesser loosestrife) poisoning of sheep in Victoria

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.     

Chloramphenicol concentrations in calf muscle tissue

Twenty-five 9- to 11-week-old calves were administered 2 doses of chloramphenicol prepared in propylene glycol (13.6 mg/kg of body weight IV; 6.8 mg/kg IM; or 13.6 mg/kg IM) at 24-hour intervals. Calves were euthanatized at designated times from 2 to 72 hours after the last dose was administered. Muscle tissues were collected immediately after euthanasia, and chloramphenicol concentrations in the tissues were determined.     

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

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.