A physiologically based pharmacokinetics model for florfenicol in crucian carp and oral‐to‐intramuscular extrapolation

Yang, F., Sun, N., Sun, Y. X., Shan, Q., Zhao, H. Y., Zeng, D. P., Zeng, Z. L. A physiologically based pharmacokinetics model for florfenicol in crucian carp and oral‐to‐intramuscular extrapolation. J. vet. Pharmacol. Therap.  36 , 192–200. In this study, an oral physiologically based pharmacokinetics (PBPK) model was developed for florfenicol in crucian carp (Carassius auratus). Subsequently, oral‐to‐intramuscular extrapolation was performed and the two models were used to predict florfenicol concentrations in the edible tissues of crucian carp. The oral model gave good predictions in most tissues, except for kidney and liver in which the florfenicol concentrations were underestimated at the later time points. In contrast, using the intramuscular model, the concentrations in the kidney were overestimated at the later time points. Both models had the best predictive ability in the main edible tissue, the muscle. The oral model also accurately predicted the florfenicol concentrations in the muscle after multiple doses. The present study demonstrated the feasibility of predicting florfenicol concentrations in the edible tissues of crucian carp using a route‐to‐route extrapolation method.     

The evolution of chicken stem cell culture methods

1. The avian embryo is an excellent model for studying embryology and the production of pharmaceutical proteins in transgenic chickens. Furthermore, chicken stem cells have the potential for proliferation and differentiation and emerged as an attractive tool for various cell-based technologies.

2. The objective of these studies is the derivation and culture of these stem cells is the production of transgenic birds for recombinant biomaterials and vaccine manufacture, drug and cytotoxicity testing, as well as to gain insight into basic science, including cell tracking.

3. Despite similarities among the established chicken stem cell lines, fundamental differences have been reported between their culture conditions and applications. Recent conventional protocols used for expansion and culture of chicken stem cells mostly depend on feeder cells, serum-containing media and static culture.

4. Utilising chicken stem cells for generation of cell-based transgenic birds and a variety of vaccines requires large-scale cell production. However, scaling up the conventional adherent chicken stem cells is challenging and labour intensive. Development of a suspension cell culture process for chicken embryonic stem cells (cESCs), chicken primordial germ cells (PGCs) and chicken induced pluripotent stem cells (ciPSCs) will be an important advance for increasing the growth kinetics of these cells.

6. This review describes various approaches and suggestions to achieve optimal cell growth for defined chicken stem cells cultures and use in future manufacturing applications.     

The effect of large doses of thiamine on the horse

Extract

In conjunction with a trial to determine the effect of nematode infestation upon the liveweight gain and wool production of young sheep (Brunsdon, unpublished), information was sought on the seasonal succession and availability on pasture of infective larvae of the principal trichostrongyle genera parasitic in sheep. Data were collected in the form of nematode populations found at postmortem examination of Romney lambs, previously maintained worm-free, which were exposed to risk of parasitism in the field. A series of these lambs ran with the flock in the above-mentioned trial and served as indicators of the abundance of infective larvae on the pasture.     

Diseases of the domestic fowl in Northern New Zealand

Abstract

Extract

Information about diseases in domestic fowls in New Zealand is contained in two books (Anon., 1965 Anon. Specimens for Laboratory Examination N.Z. Department of Agriculture 1965  [Google Scholar]; Anon., 1971 Anon. Diseases of Domestic Animals in New Zealand , 3rd ed. Editorial Services Wellington 1971  [Google Scholar]). The following diseases have been the subject of separate reports: Salmonella newington infection (Flannery, 1954 Bridges, C. H. and Flowers, A. I. 1958. “Iridocyclitis and cataracts associated with an encephalomyelitis in chickens”. In Diseases of Poultry, 4th ed, Edited by: Biester, H. E. and Schwarte, L. H. Ames, Iowa: Iowa State Univ. Press. In [Google Scholar]); lead poisoning (Salisbury et al, 1958 Salisbury, R. M., Staples, E. L. J. and Sutton, M. 1958. Lead poisoning in chickens. N.Z. vet. J., 6: 2–7. [Taylor &; Francis Online] , [Google Scholar]); Ornithonyssus sylviarum infestation (Thomas and Watson, 1958 Thomas, P. L. and Watson, H. H. 1958. The occurrence in New Zealand of the northern poultry mite, Ornithonyssus sylvarium (Canestrini and Fanzago, 1877). N.Z. vet. J., 6: 47–50. [Taylor &; Francis Online] , [Google Scholar]); infectious laryngotracheitis (Webster, 1959 Webster, R. G. 1959. Studies on infectious larvnsntracheitis in New Zealand. N.Z. vet. J., 7: 67–71. [Taylor &; Francis Online] , [Google Scholar]); mycoplasmosis (Pohl, 1966 Pohl, R. M. 1966. Mycoplasmosis in poultry. N.Z. vet. J., 14: 151–151. [Taylor &; Francis Online] , [Google Scholar]); infectious bronchitis (Pohl, 1967 Pohl, R. M. 1967. Infectious bronchitis in chickens. N.Z. vet. J., 75: 151–151.  [Google Scholar]); uraemia (Pohl, 1968 Pohl, R. M. 1968. Uraemia (infectious nephritis) in chickens in New Zealand. N.Z. vet. J., 16: 188–188. [Taylor &; Francis Online] , [Google Scholar]); coccidiosis (Pohl, 1969 Pohl, R. M. 1969. Coccidiosis of the fowl in New Zealand. N.Z. vet. J., 17: 249–250. [Taylor &; Francis Online] , [Google Scholar]); vibriosis (Pohl, et al, 1969 Pohl, R. M., Marshall, R. M. and Pearson, R. 1969. Vibriosis in chickens in New Zealand. N.Z. vet. J., 17: 51–52. [Taylor &; Francis Online] , [Google Scholar]) and capillariasis (Rickard and Pohl, 1969 Rickard, M. D. and Pohl, R. 1969. Capillariasis of the domestic fowl in New Zealand. N.Z. vet. J., 17: 130–136. [Taylor &; Francis Online] , [Google Scholar]).     

Swine dysentery

Extract

Sir, — We have just received a copy of the N.Z. Veterinary Journal for August, 1975 (Vol. 23, No.8) containing a most interesting communication by Pearce and Smith on the epidemiology, diagnosis and treatment of swine dysentery.     

The amended insulin to glucose ratio and diagnosis of insulinoma in dogs

Amended insulin to glucose ratios were calculated from the concentrations of serum insulin and blood glucose measured concurrently during either a glucagon tolerance test or after feeding in healthy dogs. Values greater than 30 𝛍U/mg which are supportive of a diagnosis of insulinoma were obtained at certain times during the test period. Amended insulin to glucose ratios calculated from serum insulin and blood glucose concentrations obtained during a glucagon tolerance test and an oral glucose tolerance test on a dog with an insulinoma were less than 30 𝛍U/mg, or equivocal, at different times during the test period. This indicates that under some circumstances healthy dogs may have elevated amended insulin to glucose ratios, and dogs with insulinoma may have a normal amended insulin to glucose ratio. Care is essential for interpretation of amended insulin to glucose ratios, and a diagnosis of insulinoma using the ratio must be made in conjunction with appropriate clinical signs of hvnoglvcaemia.     

The direct and residual effects of the fertilisation of a grass/clover pasture

The results of a factoral experiment in which various fertiliser treatments were applied to a mixed Paspalum dilatatum and N.Z. wild white clover pasture have indicated that under conditions of complete crop removal, highly significant responses to the application of nitrogen, phosphate and potash can be expected. The results have also indicated that the response of the pasture to phosphate applications depends on the type of phosphate used and whether it is applied as a basal treatment or as annual top‐dressings. Although these mean effects were of significance when the total production of herbage over five years was statistically analysed, the analysis of the seasonal yields indicated that the significance of the treatments declined with the passage of time. The results obtained from maize crops which followed the pasture phase of the experiment indicated that the application of fertiliser to the pasture was inadequate in meeting the demands of the pasture crop with the result that the plant nutrient resources of the soil were severely depleted. It was shown, however, that the productivity of the soil could be restored by the application of adequate quantities of fertiliser.     

The efficacy of oxfendazole administered as a bolus compared with a drench formulation

Summary

In a flock of 40 ewe lambs of the Texel breed the anthelmintic oxfendazole was tested in two different formulations, a 2.265 per cent suspension and a 4 gram bolus containing 151 mg active ingredient. All treatments were based on a dose rate of 5 mg / kg body weight. Faecal examinations and larval differentiations were carried out on the day of treatment and two and seven days later. No differences in efficacy were apparent between the two treated groups.

Oxfendazole in either formulation was 100 per cent effective in removing the major strongylids and trichostrongylids.

A lower activity was seen against Strongyloides papillosus.