The construction and application of a population physiologically based pharmacokinetic model for methadone in Beagles and Greyhounds

Methadone is an opioid analgesic in veterinary and human medicine. To help develop appropriate pain management practices and to develop a quantitative model for predicting methadone dosimetry, a flow‐limited multiroute physiologically based pharmacokinetic (PBPK) model for methadone in dogs constructed with Berkeley Madonna? was developed. The model accounts for intravenous (IV), subcutaneous (SC), and oral administrations, and compartmentalizes the body into different components. This model was calibrated from plasma pharmacokinetic data after IV administration of methadone in Beagles and Greyhounds. The calibrated model was evaluated with independent data in both breeds of dogs. One advantage of this model is that most physiological parameter values for Greyhounds were taken directly from the original literature. The developed model simulates available pharmacokinetic data for plasma concentrations well for both breeds. After conducting regression analysis, all simulated datasets produced an R ² > 0.80 when compared to the measured plasma concentrations. Comparative analysis of the dosimetry of methadone between the breeds suggested that Greyhounds had ~50% lower 24‐hr area under the curve (AUC) of plasma or brain concentrations than in Beagles. Furthermore, population analysis was conducted with this study. This model can be used to predict methadone concentrations in multiple dog breeds using breed‐specific parameters.     

The Past,Present and Future of Domestic Equines in Tanzania

Equines are minor species in Tanzania’s array of domestic livestock. Attempts to use them for transport by early explorers from the mid-nineteenth century usually failed. Donkeys were used extensively as pack animals to complement human porters by both British and German forces in the First World War, but their advantages were often outweighed by slow progress and competition with troops and porters for water, and they died in huge numbers. The British had regular cavalry troops in their campaign and mules found limited use as individual mounts for officers. In modern times, there are very few horses in Tanzania but they find several uses. Exotic safaris are made on horseback, they are used as stock horses on ranches, there is a polo club in northern Tanzania and there are leisure riding activities around the capital city. Official census records for donkeys estimate numbers at under 300,000 with concentrations in the northern pastoral and agropastoral areas where they are used as pack animals with water being the main commodity transported. Elsewhere donkeys are used to a limited extent in transport and traction work. There is little interest in equines by the central and local governments or the general public and the status quo can be expected to continue.     

Production of a macrophage chemotactic factor by cultured jaagsiekte tumour cells

The increase of alveolar macrophages in jaagsiekte sheep lungs is not caused by excessive surfactant production but is due to a chemotactic factor secreted by the tumor cells. This factor has a molecular mass in the region of 13 kilodaltons, is stable at 56 degrees C but labile at 100 degrees C and, being sensitive to proteases, indicates that it is a small protein molecule.     

BOOK REVIEW

A Symposium on Training Programs in Tropical Animal Health and Production, Townsville 1987 . Ed. P W Ladds     

Earthworm ecological groupings based on C analysis

We report the first use of ¹⁴C isotope analysis to investigate the ecological grouping of earthworms. Mature endogeic (Allolobophora caliginosa), mature epigeic (Lumbricus rubellus), and semimature anecic worms (A. longa) were collected in September 2002 from a woodland site at Lancaster, UK. Because anecic worms are known to have a variable feeding behaviour and can show dietary changes during ontogeny, additional immature and mature specimens of A. longa were also collected from the same site in January 2004. Epigeic earthworms showed the lowest radiocarbon concentration (0-3-years old), implying that they assimilated more recently fixed carbon than the anecic or endogeic earthworms. The age of carbon assimilated in mature anecic species (5-7-years old) was closer to that of endogeic species (5-8-years old) than to epigeics, suggesting that a greater proportion of older, more mineralised organic matter may form part of the diet of the anecic earthworms than previously thought. These results suggest that ¹⁴C approaches are useful in the study of the feeding behaviour of detritivorous animals by providing in situ information on the age of the carbon assimilated by the worms. This can then be related to their role in ecosystem functioning, particularly in carbon cycling.     

The production of azadirachtin by in-vitro tissue cultures of neem,Azadirachta indica

Callus produced from leaves of a Ghanaian strain of the neem tree, Azadirachta indica A. Juss has been shown to produce the natural insecticide azadirachtin when grown in a defined medium. The azadirachtin was isolated by standard procedures of solvent partition and column chromatography monitored by supercritical fluid chromatography. Biological activity was monitored with antifeedant tests using the desert locust (Schistocerca gregaria Forsk.). The azadirachtin was identified by chromatography on three independent chromatographic systems (SFC, HPLC & TLC) and two thin-layer colour tests. It has 100% antifeedant activity at < 0.04mg litre^?1. The yield of azadirachtin was 0.0007% based on dry weight of callus.     

Applying the FAO Guidelines on land evaluation for forestry

This paper describes a trial application of the Food and Agriculture Organization (FAO) Guidelines on Land Evaluation for Forestry, which have been developed at the request of the International Union of Forestry Research Organizations (IUFRO).The study was carried out in mainly unlogged eucalypt forest in the Wandella-Dampier region on the South Coast of New South Wales, Australia. The study area of 49 000 ha was divided into 249 land units on the basis of field survey, as well as aerial photography and map interpretation. Rules were devised for evaluating the suitability of each land unit for the following seven land uses; general forestry, recreation, visual resource protection, flora and fauna protection, catchment protection, undeveloped natural forest and preserved natural forest. The FAO guidelines proved to be an effective basis for forest land evaluation.