The role of extruded disk material in thoracolumbar intervertebral disk disease: a retrospective study in 40 dogs

The objective of the study was to determine the effect of the dispersed or nondispersed form of the extruded disk material (EDM) on the neurological status and surgical outcomes in Hansen thoracolumbar intervertebral disk disease Type I (IVDD-I). Medical records of 40 dogs with IVDD-I were reviewed, including neurologic status on admission, findings on magnetic resonance imaging (MRI), intraoperative findings, and surgical outcomes. In MRI evaluations, EDM was on the right in 16, on the left in 18, and centrally in 6 cases; in all cases, findings were confirmed by surgery. Extruded disk material was localized and classified as dispersed disk (DD) or nondispersed disk (NDD) according to its dispersion in the epidural space on MRI. Twenty-five dogs had DD and 15 had NDD on both MRI and surgery. There was no significant difference between DD and NDD in preoperative neurological status and surgical outcomes (P > 0.05).     

The kinetics of insecticide action. Part IV: the in-vivo distribution of pyrethroid insecticides during insect poisoning

The distribution of pyrethroids in insects has been studied using a combination of mathematical modelling and experimental observation. This approach has resulted in the formulation of a physiological model of the pharmaco-kinetics of cypermethrin applied topically to larvae of Spodoptera littoralis. Development of this model from simpler two- and three-compartment models is described. Simple models, whilst capable of complex behaviour, consider only the average rates and magnitudes of pharmaco-kinetic processes over whole animals, and cannot account for differences in concentration of insecticide between individual tissues. This can be achieved by using physiological models, but these require more experimental information for their validation. Moreover, unless simplifying assumptions are made, analytical solutions are not feasible for the large number of equations necessary to define such models. The modelling studies prompted an investigation of (1) in-vivo binding of insecticide to insect tissues, (2) the sizes of body compartments, and (3) the factors which affect the distribution of toxicant between these compartments. Binding has a marked effect on pharmacokinetic profiles and may result in oscillatory behaviour. During poisoning, the total bound cypermethrin increases proportionally to the cube root of the elapsed time. This results in a rapid rate of increase over early elapsed times (< 3h) which slows to approach a more linear form thereafter. Average sizes for the body compartments of larvae of Spodoptera littoralis Boisd, and the steady-state distribution of cypermethrin in these compartments are described. Although the haemolymph, which acts as the main distributive phase during poisoning, forms the largest compartment by volume, it has a low affinity for cypermethrin and distribution reaches steady state within 5 min after topical application. The nerve cord (the target tissue), which is the smallest compartment, has the highest steady-state concentration of cypermethrin. The distribution of cypermethrin in larval tissues is related to the ratios of tissue dry matter to water content.     

Impacts of the Management of Radioactively Contaminated Land on Soil and Phosphorus Losses in Finland and Scotland

Although radioactive contamination of agricultural land mayrequire food production to cease, in many situations food contamination can be kept below the intervention limits throughapplication of countermeasures. However, the radiological benefits of these measures may be accompanied by negative impacts on the environment. The aim of this work was to assessthe impacts of selected countermeasures on water quality via losses of soil and phosphorus in river catchments in Scotland and Finland. Four countermeasures, suitable for different levelsof radioactive deposition, were studied: deep ploughing, skim and burial ploughing, changes in the feeding of livestock andcessation of production. The assessments were performed using adeterministic mathematical simulation model capable of estimatingthe impact of changes in management practices and land use on thehydrology and on soil and phosphorus losses from land to water.Skim and burial ploughing had the least impacts. Deep ploughinggenerally reduced phosphorus losses but had variable effects on soil loss, which depended on the erodibility of the subsoil. Changes in the dairy feeding regime from roughage-dominated (local grass production) to more concentrates (local cereal production or imported) had variable impacts, depending on the local agricultural systems and management practices. The worstimpacts on erosion and phosphorus losses may occur where large areas of grassland are converted to cereal production. Cessationof agricultural production resulted in large (50–90%) reductions in soil and phosphorus losses. The most recommended ofthe assessed countermeasures is skim and burial ploughing, but its wider use depends on the availability of specialized technical equipment.     

Efficacy of an intranasal modified live bovine respiratory syncytial virus and temperature-sensitive parainfluenza type 3 virus vaccine in 3-week-old calves experimentally challenged with PI3V

Two experimental parainfluenza type 3 virus (PI3V) challenge studies were undertaken to evaluate the efficacy of a single intranasal dose of an attenuated live vaccine containing modified live bovine respiratory syncytial virus (BRSV) and temperature-sensitive PI3V in 3-week-old calves. In the first study, vaccine efficacy was evaluated in colostrum deprived calves. Nasal shedding of PI3V was highly significantly reduced in vaccinated calves challenged 10 days or 21 days after vaccination. In the second study, vaccine efficacy was assessed in calves with maternal antibodies against PI3V by challenge 66 days post-vaccination. Vaccination also significantly reduced PI3V excretion after challenge in this study. In both studies, clinical signs after challenge were very mild and were not different between vaccinated and control calves.     

Priorities towards national-level soil protection: a survey of soil stakeholders in Scotland

Abstract. Soil protection policies are being developed in many countries, particularly those in the European Union where pan-national regulatory frameworks now exist. We report an analysis of a survey of the views of a wide range of stakeholders in the soil resource of Scotland, including representatives of rural and urban land users, public bodies and authorities, non-governmental environmental organizations, and soil scientists based in Scotland. The four soil issues considered of particular importance were soil pollution, soil erosion, loss of soils to development, and loss of biodiversity. Comments were strongly polarized, either strongly promoting issues or indicating lack of awareness, on a set of topics: the loss of valued soils, loss of archaeological sites, and changes in terrestrial carbon store. It is argued that an integrated approach is required to implement any future soil protection strategies, and that special attention should be paid to monitoring long-term changes and to provision of soil survey data from urban areas.     

Degradation of ethylenethiourea on lettuces

The rates of uptake and loss of ethylenethiourea (ETU) in lettuces were studied following the application of ethylenethiourea or selected ethylenebisdithiocarbamate fungicides to the soil or to the leaves of potgrown plants. Analyses were carried out using high performance liquid chromatographic analysis of ETU. The amounts of ETU residues on leaves decreased rapidly and were negligible within a week, unless ethylenebisdithiocarbamate fungicides had been applied to the soil, as the latter were degraded simultaneously to give additional ETU which was then taken up by the plants.