Secondary plant metabolites as targets for genetic modification of crop plants for pest resistance

Three genetic manipulation strategies are described for enhancing the effectiveness of secondary metabolites of crop plants in reducing pest and disease damage. Targets for gene transfer studies are secondary metabolites of oilseed rape, lepidopteran sex pheromones and drimane anti-feedants. Initial work towards isolation of genes for the biosynthesis of drimane anti-feedants is described.     

Dog-human and dog-dog interactions of 260 dog-owning households in a community in Cheshire

This study investigated the nature and frequency of the contacts that occur between dogs, and between dogs and people, by means of a questionnaire survey of 260 dog-owning households in a community in Cheshire, uk. The contacts were highly variable and were affected by the size, sex and age of the dog, individual dog behaviours, human behaviours and human preferences in the management of the dog. A number of situations were identified that may be important in relation to zoonoses, including sleeping areas, playing behaviours, greeting behaviours, food sources, walking, disposal of faeces, veterinary preventive treatment and general hygiene.     

Monitoring derelict urban land: A review of problems and potentials of remote sensing techniques

The accelerating rate of change in urban areas calls for more rapid and cost-effective surveys of derelict land. A review of the use of remote sensing¹ for this task reveals that, although aerial photography has been used for urban analysis since the 1940s, it has not been widely adopted for surveys of derelict land, despite demonstrations of its utility. Other forms of remote sensing are similarly shown to have been little-used and to have had patchy success. The hitherto restricted utility of remote sensing is found to be due to a combination of limitations of the forms of imagery available and the methods of analysis employed. Recent changes in available remote sensing imagery, notably the higher resolution now provided by the SPOT satellite, coupled with advances in digital image-processing techniques point to improved opportunities for using remote sensing to monitor derelict land. As a demonstration of these developments, a texture image based on scene variance is derived from a SPOT image of part of north Staffordshire. All derelict and neglected land parcels larger than 1.25 ha are delimited on this image. Remote sensing techniques are not yet ready to supplant detailed ground surveys but they have a growing role to play in monitoring various aspects of land dereliction.     

Gas-liquid chromatographics determination of Bayer 73 in fish, aquatic invertebrates, mud, and water

A gas-liquid chromatographic (GLC) method is described for determining residues of Bayer 73 (2-aminoethanol salt of 2',5-dichloro-4'-nitrosalicylanilide) in fish muscle, aquatic invertebrates, mud, and water by analyzing for 2-chloro-4-nitroaniline (CNA), a hydrolysis product of Bayer 73. Bayer 73 residues are extracted from fish muscle tissue, invertebrates, and mud with acetone-formic acid (98+2), and partitioned from water samples with chloroform. After sample cleanup by solvent and acid-base partitioning, the concentrated extract is hydrolyzed with 2N NaOH and H2O2 for 10 min at 95 degrees C. The CNA is then partitioned into hexane-ethyl ether (7+3) and determined by electron capture GLC. Average recoveries were 88% for fish, 82% for invertebrates, 82% for mud, and 98% for water at 3 or more fortification levels.     

Antigenic and morphological differentiation of placental and intestinal isolates of Chlamydia psittaci of ovine origin.

Ewe placental and lamb intestinal isolates of Chlamydia psittaci recovered from flocks affected with ovine enzootic abortion were examined by inclusion morphology, indirect immunofluorescence (IIF) and immunoblot analysis. Chlamydiae recovered from the faeces of sheep from two flocks free of clinical disease were also examined. In cell culture ovine abortion (OA) and intestinal isolates were distinguishable by inclusion development and morphology. Similarly, in two-way IIF tests with one week mouse antisera isolates fell into two distinct groups: abortion or intestinal. Immunoblotting with convalescent sheep abortion antiserum identified 30 out of at least 40 silver staining polypeptides as antigenic both in OA and intestinal isolates. The serum produced a similar reaction pattern to the resolved proteins of each OA isolate, indicating a higher degree of antigenic conservation among these isolates. Considerable cross reactivity between the OA and intestinal isolates was identified, but the serum also showed apparent molecular weight differences between antigens of the two types in the 87-116 kDa, 38-44 kDa and 26-28 kDa regions. Furthermore, the immunoblotting analysis revealed heterogeneity among the intestinal isolates, particularly in antigens between 87-116 kDa and 38-44 kDa.     

Bovine spongiform encephalopathy: detection and quantitation of fibrils, fibril protein (PrP) and vacuolation in brain

Bovine spongiform encephalopathy (BSE) is a new disease of cattle which has considerable homology with scrapie, the archetype of the transmissible spongiform encephalopathies. Abnormal brain fibrils, called scrapie associated fibrils (SAF), are specific ultrastructural markers for these diseases. Fibril detection was compared with histopathological diagnosis in the brains of 167 cattle; 157 clinically suspect BSE and 10 clinically normal. Fibrils were detected in samples of pooled brain regions of 67/144 in which vacuolar changes of BSE were confirmed, but absent in the remaining 23 brains, in which no vacuolation was found, including those from the clinically normal cattle and 13 with alternative neuropathological diagnoses. When eight defined anatomic regions from the brains of another 22 affected cows were examined, the sensitivity of fibril detection was greater than 90% for the brain stem areas. Fibril prevalence in these areas approximated to severity of vacuolar changes. When the same defined regions from four of the affected cows were assayed for fibril protein (PrP) by western blotting, the density of immuno-labelling generally correlated with the fibril prevalence. This study confirms the specificity of fibril detection for BSE, shows that the ease of fibril detection depends on anatomic region sampled and suggests an association between PrP accumulation and vacuolar changes in certain neuroanatomic areas.     

Effects of supplemental fructooligosaccharides plus mannanoligosaccharides on immune function and ileal and fecal microbial populations in adult dogs.

The goal of this study was to examine whether supplemental fructooligosaccharides (FOS) plus mannanoligosaccharides (MOS) influenced immune function and ileal and fecal microbial populations of adult dogs. Eight adult dogs surgically fitted with ileal cannulas were used in a crossover design. Dogs were fed 200 g of a dry, extruded, kibble diet twice daily. At each feeding, dogs were dosed with either 1 g sucrose (placebo) or 2 g FOS plus 1 g MOS orally via gelatin capsule. Fecal, ileal, and blood samples were collected at the end of each 14-d period to measure microbial populations and immune characteristics. Treatment least squares means were compared using the GLM procedure of SAS. Supplementation of FOS plus MOS increased fecal bifidobacteria and fecal and ileal lactobacilli concentrations. Dogs fed FOS plus MOS also tended to have lower blood neutrophils and greater blood lymphocytes vs placebo. Serum, fecal, and ileal immunoglobulin concentrations were unchanged by treatment. Supplementation of FOS plus MOS beneficially altered indices of gut health by improving ileal and fecal microbial ecology. Supplementation of FOS plus MOS also altered immune function by causing a shift in blood immune cells.