Emerging infectious diseases of wildlife--threats to biodiversity and human health

Emerging infectious diseases (EIDs) of free-living wild animals can be classified into three major groups on the basis of key epizootiological criteria: (i) EIDs associated with "spill-over" from domestic animals to wildlife populations living in proximity; (ii) EIDs related directly to human intervention, via host or parasite translocations; and (iii) EIDs with no overt human or domestic animal involvement. These phenomena have two major biological implications: first, many wildlife species are reservoirs of pathogens that threaten domestic animal and human health; second, wildlife EIDs pose a substantial threat to the conservation of global biodiversity.     

Yankee Supreme: A new bruise-resistant potato variety

The Yankee Supreme potato is a medium to medium-late maturing variety with round to oblong, moderately smooth, shallow-eyed, buff-colored tubers. It is characterized by bruise resistance and high dry matter. Tubers can be used for fresh market or processing. Although chip color is often marginal, this variety can be reconditioned to its original color after cold storage. Yankee Supreme is resistant to virus X and to net necrosis caused by the leaf-roll virus.     

Campbell 14: A verticillium resistant round white potato variety

The Campbell 14 potato variety is a medium-late maturing variety with round to oblong, smooth, shallow-eyed, white tubers. This variety is intended primarily for fresh market; however, under some conditions chip color will be acceptable. Campbell 14 is resistant to verticillium wilt and to the net necrosis caused by the potato leafroll virus.     

Phosphodiesterase activity in neutrophils from horses with chronic obstructive pulmonary disease

Neutrophils are recruited to the lungs of horses with chronic obstructive pulmonary disease (COPD) and exhibit increased activity after antigen challenge. Phosphodiesterase type4 (PDE4) inhibitors have been shown to attenuate human neutrophil activation. The aim of this study was to establish the PDE isoenzyme profile of equine neutrophils using isoenzyme selective inhibitors to determine if these compounds should be evaluated in horses with COPD. Total cAMP and cGMP dependent PDE activity was no different in neutrophils from normal (156.2+/-7.1 and 6.8+/-0.6 pmol/min/mg for cAMP and cGMP, respectively) and COPD susceptible horses (146.0+/-10.2 and 5.5+/-0.6 pmol/min/mg for cAMP and cGMP, respectively). The PDE4 inhibitors, CDP840 and rolipram, caused significant, concentration related and almost complete inhibition of PDE activity (IC(50) values=8.8+/-0.1 x 10(-9) and 7.3+/-0.2 x 10(-9)M for CDP840; 1.2+/-0.1 x 10(-6) and 1.1+/-0.1 x 10(-6)M for rolipram in normal and COPD susceptible horses, respectively). The inhibitory effects of the mixed PDE3/ PDE4 inhibitor, zardaverine were of similar magnitude and potency to rolipram. However, the limited inhibitory effects of the PDE3 inhibitor, siguazodan, suggest that zardaverine is acting primarily via PDE4 inhibition. These results indicate that PDE4 is the predominant isoenzyme present in the equine neutrophil and inhibition of PDE activity using selective PDE4 inhibitors may, therefore, modulate equine neutrophil activation in horses with COPD.     

The future requirements and availability of veterinary manpower for New Zealand

Extract

The 1965 Annual Meeting of the New Zealand Veterinary Association endorsed a proposal to examine the future requirement for veterinary manpower in New Zealand. Support was subsequently forthcoming from members of the Association and from organizations interested in veterinary activities in providing data on which estimates could be based. Information was obtained on changes in the numbers of veterinary surgeons and in their employment in the past 15 years and on the estimated requirement for veterinary surgeons at the end of the forthcoming 15 years. A period of 15 years was regarded as one for which records are likely to be reliable and for which projections could be expected to have reasonable accuracy. The examination of data collected in this way forms the first part of this report.     

Endotoxin and dietary amines may increase plasma 5-hydroxytryptamine in the horse

Uptake of 5-hydroxytryptamine (5-HT) into platelets is an important mechanism by which low plasma concentrations are maintained, and platelet activation may therefore result in significant release of this vasoconstrictor. The present study examined the kinetics of active uptake of radiolabelled [3H]5-HT by washed equine platelets in vitro, and investigated the effects on this process of 4 other naturally occurring monoamines which may be released from the caecum in conditions of carbohydrate overload. The release of [3H]5-HT by platelets was also studied, since platelet accumulation and activation has been associated with acute laminitis. Release of [3H]5-HT was measured in response to platelet activating factor (PAF), unlabelled 5-HT and the indirect activation of platelets by endotoxin in the presence of blood leucocytes. Km value for the uptake of 5-HT by equine platelets was 2.4 +/- 0.6 micromol/l and the Vmax was 8.3 +/- 0.6 pmol [3H]5-HT/10(7) platelets/min. The rate of uptake of 5 micromol/l [3H]5-HT was significantly decreased by the uptake inhibitors fluvoxamine and clomipramine. The 4 other monoamines examined all inhibited the uptake of [3H]5-HT in a noncompetitive manner, decreasing Vmax by between 17 and 82%. Incubation of platelets with LPS (0.1 mg/ml) in the absence of leucocytes did not result in significant release of [3H]5-HT; however, in the presence of leucocytes 3.8 +/- 1.7 pmol [3H]5-HT/10(7) platelets (mean +/- s.e.) were released. This release was significantly inhibited by parthenolide and WEB2086, but not by aspirin. This suggests that PAF from activated leucocytes was responsible for the 5-HT release. These data show that 5-HT uptake by equine platelets is a saturable process operating most efficiently at substrate concentrations in the low micromolar range. The noncompetitive inhibition of 5-HT uptake by other naturally occurring monoamines may result in increased plasma concentrations of 5-HT, as would its release by endotoxin. Such a rise in plasma 5-HT concentrations may contribute to selective vasoconstriction in the equine digital circulation.