Comparison of intradermal testing and serum testing for allergen-specific IgE using monoclonal IgE antibodies in 84 atopic dogs

OBJECTIVE: To compare an ELISA measuring serum allergen-specific IgE with intradermal skin testing in canine atopic dermatitis. PROCEDURE: Eighty-four dogs with the clinical diagnosis of atopic dermatitis underwent intradermal skin testing and serum testing for allergen-specific IgE. Tests were performed in a blinded fashion. Positive reactions were compared and the sensitivity and specificity of the serum test (using intradermal skin test as the standard) were determined overall and for individual allergen groups (grass pollens, weed pollens, tree pollens, house dust mites and fleas). RESULTS: The sensitivity of the ELISA overall was 90.4%. Evaluating the individual allergen groups, the sensitivity for dust mite hypersensitivity was 95.1%, for fleas 85.4%, for tree pollens 84.3%, for grass pollens 95.1% and for weed pollens 96.4%. The specificity was 91.6% overall, for dust mites 96.3%, for fleas 92.7%, for tree pollens 95.2%, for grass pollens 94% and for weed pollens 80.7%. CONCLUSION: The evaluated ELISA seemed reliable for the diagnosis of atopy in practice and can be recommended as a screening test prior to intradermal skin testing or for use in dogs when immunotherapy is not a therapeutic option.     

Activation of Zona‐Free Buffalo (Bubalus bubalis) Oocytes by Chemical or Electrical stimulation,and Subsequent Parthenogenetic Embryo Development

Parthenogenetic activation using zona‐free oocytes offers an alternative model that could be applied to develop protocols for the activation of reconstructed embryos for cloning. The aim of this study was to compare the efficacy of different methods for the activation of zona‐free buffalo oocytes in terms of their effects on the developmental competence of parthenogenetic embryos. The effects of zona removal on parthenogenetic activation and in vitro developmental competence of metaphase II oocytes were also examined. All activation methods were followed by incubation of 2 mm 6‐dimethylaminopurine (6‐DMAP) for 4 h. Out of three different pulse strengths (1.2, 2.1 or 3.3 kV/cm) used, 2.1 kV/cm resulted in the highest blastocyst rate (25.3%). On comparing different chemical agents and electric pulse, highest blastocyst rate was observed for calcium ionophore (CaI) (28.6%) followed by ethanol (25.0%), electric pulse (22.5%) and combined CaI and ethanol treatment (16.7%) although differences among them were not significant. Furthermore, a significantly reduced developmental potential was observed in zona‐free oocytes when compared to zona‐intact ones up to the blastocyst stage (44.3% vs 27.1%). In conclusion, zona‐free buffalo oocytes can be successfully activated for parthenogenetic development using chemical or electrical stimulation. Out of different agents examined, CaI followed by 6‐DMAP resulted in the highest blastocyst rate.     

Oocyte viability and cortical activation under different salt solutions in Prochilodus lineatus (Teleostei: Prochilodontidae)

This study aimed to evaluate the effect of five salt solutions in the maintenance of morphological features of cortical alveolus, hydration and fertilization capacity of Prochilodus lineatus oocytes. For this purpose, five saline solutions were tested: Ringer's solution, Ringer's lactate solution, Hank's balanced salt solution (HBSS), Hank's balanced salt solution without calcium (HBSS without calcium) and solution for salmonid eggs. Oocytes were maintained for 2 hr in saline solution with controlled temperature subsequently evaluated for hydration, cortical activation and fertilization ability. In the evaluation of the fertilization ability, two controls were used: C1—fertilized oocytes after extrusion—and C2—oocytes kept in ovarian fluid and fertilized after 2 hr. There was a significant reduction in the viability of oocytes C2 (28.8% ± 12.9%) compared to C1 (65.3% ± 26.7%), and no significant differences were found between treatments HBSS and HBSS without calcium and C2. Only HBSS and HBSS without calcium maintained the non‐activated state of the gametes, with a fertilization rate of 16.4% ± 6.7% and 5.6% ± 2.3%, respectively; however, they did not extend the viability of oocytes, such that they continued to undergo degradation during the storage period, similar to oocytes retained only in ovarian fluid.     

Development of a modified cortisol extraction procedure for intermediately sized fish not amenable to whole-body or plasma extraction methods

The corticosteroid hormone cortisol is the central mediator of the teleost stress response. Therefore, the accurate quantification of cortisol in teleost fishes is a vital tool for addressing fundamental questions about an animal’s physiological response to environmental stressors. Conventional steroid extraction methods using plasma or whole-body homogenates, however, are inefficient within an intermediate size range of fish that are too small for phlebotomy and too large for whole-body steroid extractions. To assess the potential effects of hatchery-induced stress on survival of fingerling hatchery-reared Spotted Seatrout (Cynoscion nebulosus), we developed a novel extraction procedure for measuring cortisol in intermediately sized fish (50–100 mm in length) that are not amenable to standard cortisol extraction methods. By excising a standardized portion of the caudal peduncle, this tissue extraction procedure allows for a small portion of a larger fish to be sampled for cortisol, while minimizing the potential interference from lipids that may be extracted using whole-body homogenization procedures. Assay precision was comparable to published plasma and whole-body extraction procedures, and cortisol quantification over a wide range of sample dilutions displayed parallelism versus assay standards. Intra-assay  %CV was 8.54 %, and average recovery of spiked samples was 102 %. Also, tissue cortisol levels quantified using this method increase 30 min after handling stress and are significantly correlated with blood values. We conclude that this modified cortisol extraction procedure provides an excellent alternative to plasma and whole-body extraction procedures for intermediately sized fish, and will facilitate the efficient assessment of cortisol in a variety of situations ranging from basic laboratory research to industrial and field-based environmental health applications.