Plasma concentration, mammary excretion and side-effects of phenylbutazone after repeated oral administration in healthy cows

Seven clinically healthy dairy cows were each given 2.5 gphenylbutazone (approximately 5 mg/kg body weight) by oral administration twice daily for 8 days. The concentrations of phenylbutazone in plasma and milk and several blood parameters were studied. The minium plasma concentration during steady state was 100.4 ± 7.3 μg/ml. During the same period the milk concentration never exceeded 1% of the plasma concentration. The elimination half-life in plasma was 38.6 ± 3.7 h. Five days after administration had been discontinued, the milk concentration was 0.05 ± 0.01 μg/ml. All seven cows were clinically healthy throughout the experiment. The most pronounced side-effect of the blood parameters studied was a decreased concentration of leucocytes to about two-thirds of the control value. This might have a pronounced influence on the effectiveness of the immune system. There was also a significant decrease in total bilirubin indicating a decrease in the breakdown of erythrocytes.     

Withdrawal time of four pharmaceutical formulations of enrofloxacin in poultry according to different maximum residues limits

San Martin, B., Cornejo, J., Lapierre, L., Iragüen, D., Pérez, F., Hidalgo, H., Andre, F. Withdrawal time of four pharmaceutical formulations of enrofloxacin in poultry according to different maximum residues limits. J. vet. Pharmacol. Therap. 33 , 246–251. To ensure delivery of safe animal products to consumers, the withdrawal time (WDT) of drugs must be respected. Property differences among pharmaceutical formulations, for the same drugs, can lead to differences in the WDTs estimation. The WDTs of four commercial formulations of enrofloxacin (ENRO) in broiler chickens, considering MRLs established by different countries, were studied. Two hundred‐thirty‐four broiler chicks were allotted among four groups; the formulations were orally administered daily with 10 mg/kg bw. After treatment, six chickens of each group and two controls were slaughtered daily until day 9 post‐treatment. Samples of muscle and liver were collected, and analyzed using HPLC‐MS‐MS. The WDTs among formulations of ENRO showed differences of 24 and 48 h. Based on the European Community and Chile MRLs of 100 μg/kg (muscle) and 200 μg/kg (liver), the WDTs did not exceed 5 days. When Japan MRL was considered (10 μg/kg_,), the WDTs increased up to 8 days. These results indicate that for WDTs determination, the differences among pharmaceutical formulations of a drug must be considered as well as the MRLs.     

Insect nicotinic acetylcholine receptor agonists as flea adulticides in small animals

Vo, D. T., Hsu, W. H., Abu‐Basha, E. A., Martin, R. J. Insect nicotinic acetylcholine receptor agonists as flea adulticides in small animals. J. vet. Pharmacol. Therap. doi: 10.1111/j.1365‐2885.2010.01160.x. Fleas are significant ectoparasites of small animals. They can be a severe irritant to animals and serve as a vector for a number of infectious diseases. In this article, we discuss the pharmacological characteristics of four insect nicotinic acetylcholine receptor (nAChR) agonists used as flea adulticides in dogs and cats, which include three neonicotinoids (imidacloprid, nitenpyram, and dinotefuran) and a macrocyclic lactone (spinosad). Insect nAChR agonists are one of the most important classes of insecticides, which are used to control sucking insects on both plants and animals. These novel compounds provide a new approach for practitioners to safely and effectively eliminate adult fleas.     

Is observed variability in the long-term results of the Continuous Plankton Recorder survey a response to climate change?

In the more than 50 years that the Continuous Plankton Recorder (CPR) survey has operated on a regular monthly basis in the north-east Atlantic and North Sea, large changes have been witnessed in the planktonic ecosystem. These changes have taken the form of long-term trends in abundance for certain species or stepwise changes for others, and in many cases are correlated with a mode of climatic variability in the North Atlantic, either: (1) the North Atlantic Oscillation (NAO), a basin-scale atmospheric alteration of the pressure field between the Azores high pressure cell and the Icelandic Low; or (2) the Gulf Stream Index (GSI), which measures the latitudinal position of the north wall of the Gulf Stream. Recent work has shown that the changes in the GSI are coupled with the NAO and Pacific Southern Oscillation with a 2 year lag. The plankton variability is also possibly linked to changes observed in the distribution and flux of water masses in the surface, intermediate and deep waters of the North Atlantic. For example, in the last two decades, the extent and location of the formation of North Atlantic Deep Water, Labrador Sea Intermediate Water and Norwegian Sea intermediate and upper-layer water has altered considerably. This paper discusses the extent to which observed changes in plankton abundance and distribution may be linked to this basin-scale variability in hydrodynamics. The results are also placed within the context of global climate warming and the possible effects of the observed melting of Arctic permafrost and sea ice on the subpolar North Atlantic.     

The Economics of a Private Forestry Enterprise in South-east Scotland

The annual income and expenditure accounts have been summarizedfor the period 1949–61. The woods had not previously beenunder regular management and due to war fellings were only 60per cent, stocked in 1949. The treatment policy has been restockingand rehabilitation with minimum cash investment. The local conditions,management history, and growing stock are briefly described,and a book valuation is presented to show value of land plusgrowing stock at the beginning and at the end of the period.The book profit on 806 acres averaged ?5. 6s. per acre per annum,of which ?3 per acre is increase in book valuation. This isequivalent to a yield of 6.4 per cent, on an average book valueof the land plus growing stock of ?70,000. The yield per cent,is expected to fall as the capital value of the growing stockincreases. Although these figures may give a reasonably accurateaccount of the financial results, it is considered that theyunderestimate the true value of the woodlands to the estateeconomy.