Equine strongyles II. Occurrence of anthelmintic resistance in Switzerland

The occurrence of anthelmintic resistance in strongyles was investigated in 440 horses on 90 farms in Switzerland. The egg hatch assay suggested that benzimidazole (BZ)-resistance was present in 40 of 82 farms (49%). Faecal egg count reduction after pyrantel-treatment was above 96% in 14 of 15 farms. In the remaining farm the efficacy was only 80%. Ivermectin efficacy was investigated on 5 farms and the efficacy was recorded at 98-100%. Faecal cultures undertaken after treatment revealed almost exclusively larvae of the family Cyathostominae. Data about management practices, pasture hygiene and anthelmintic usage were obtained with a questionnaire. Horses were treated on average 3.5 times per year. In 75% of the farms BZ were a component of the seasonal treatment schedule. Only the use of BZ had a significant correlation with the presence of BZ-resistance (P < 0.01). Recommendations for the control of equine strongyles should include measures that minimize the risk of resistance developing against remaining effective anthelmintics.     

Genetic heterogeneity of pestiviruses of ruminants in Switzerland

We have genetically analyzed ruminant pestiviruses. All >150 bovine viral diarrhea (BVD) viruses isolated from cattle in Switzerland belonged to genotype 1, with subgenogroups e, h, k and b found in decreasing frequency. To date, representatives of subgenogroup k have been detected in Switzerland only. Despite serological evidence of Border disease in sheep, only few Border disease viruses have been isolated, all of which belong to the novel group 3. Serological evidence suggested that pestivirus infections may occur also in wild ruminants in Switzerland but no isolates are available for analysis. In addition, we describe two pestiviruses, one a cell culture contaminant and the other isolated from a buffalo, that cluster with a recently proposed novel pestivirus species.     

Stimuli-responsive polymers and their applications in nanomedicine

This review focuses on smart nano-materials built of stimuli-responsive (SR) polymers and will discuss their numerous applications in the biomedical field. The authors will first provide an overview of different stimuli and their corresponding, responsive polymers. By introducing myriad functionalities, SR polymers present a wide range of possibilities in the design of stimuli-responsive devices, making use of virtually all types of polymer constructs, from self-assembled structures (micelles, vesicles) to surfaces (polymer brushes, films) as described in the second section of the review. In the last section of this review the authors report on some of the most promising applications of stimuli-responsive polymers in nanomedicine. In particular, we will discuss applications pertaining to diagnosis, where SR polymers are used to construct sensors capable of selective recognition and quantification of analytes and physical variables, as well as imaging devices. We will also highlight some examples of responsive systems used for therapeutic applications, including smart drug delivery systems (micelles, vesicles, dendrimers...) and surfaces for regenerative medicine.     

Assessment of the potential of dogs and cats as urban reservoirs of Ross River and Barmah Forest viruses

Objective To determine whether dogs and cats are potential reservoirs of Ross River (RR) and Barmah Forest (BF) viruses
Method Young seronegative female dogs and cats were experimentally exposed to the viruses using Ochlerotatus vigilax (Skuse) mosquitoes.
Results Only one of the 10 dogs and one of the 10 cats exposed to RR developed neutralising antibody. None of the animals developed detectable viraemia or clinical signs. One dog and three cats exposed to BF developed neutralising antibody. In addition, a serological survey of sera obtained from domestic dogs and cats residing in the Brisbane region indicated that 23.7% and 1.3% of dogs, and 14% and 2% of cats, had neutralising antibodies to RR and BF respectively.
Conclusions Although dogs and cats are exposed naturally to these viruses, and can become infected, they are unlikely to be important urban reservoirs of either virus.     

Temporal synergism of corticosterone and prolactin controlling gonadal growth in sparrows

Gonadal growth was controlled in two avian species by corticosterone and prolactin injected daily at various times. Testicular growth was induced in photorefractory house sparrows (Passer domesticus) kept in continuous light by prolactin injected 4 or 8 hours after administration of corticosterone. Other temporal patterns were ineffective. Gonadal growth was also stimulated in photosensitive white-throated sparrows (Zonotrichia albicollis) kept in continuous light by prolactin injected 12 hours after administration of corticosterone. Daily injections of prolactin 8 hours after injection of corticosterone inhibited gonadal growth. The seasonal cycle of reproductive photorefractoriness and photosensitivity is controlled by a changing relation between the daily rhythms of plasma concentrations of corticosterone and prolactin.     

Studies on the additive character of amino-acid absorption data obtained from pigs. 2. Studies using regression technic]

The first communication in this series (MEIER et al. 1973) reported the results of studies on the additive character of amino acid absorption data from pigs which were based on the use of the classics technique. In order to verify these results the studies were repeated, partly with the same components using regression techniques. The present studies on the additive character of amino acid absorption data showed that the additive character of these data can also be established in pigs. Moreover, the results of these investigations indicated that studies on the additive character of amino acid absorption values may be carried out by using the classical method. In performing studies of this kind attention should be paid to the fact that the rations tested should be such as to meet or nearly meet the maintenance needs of the animals.