The ACVD task force on canine atopic dermatitis (III): the role of antibodies in canine atopic dermatitis.

Although an important pathogenic role for IgE is established in the case of allergic asthma and rhinitis in man, its role in atopic dermatitis is less clear. There are many studies where allergists and immunologists have provided evidence in favour of such a role, whereas dermatologists are less than convinced.In dogs, however, there is an abundance of clinical evidence implying that atopic dermatitis is antigen driven, and recent studies suggest that there may be a role for IgE, not only in the effector pathway, but also in antigen capture. Although an IgG response often accompanies an IgE response in dogs with atopic dermatitis, there is little evidence in support of a pathogenic role in respect of the former isotype.     

Systemic properties of myclobutanil in soybean plants, affecting control of Asian soybean rust (Phakopsora pachyrhizi)

BACKGROUND: The demethylation inhibitor (DMI) fungicide myclobutanil can be an effective component of spray programmes designed to control the highly destructive plant pathogen Phakopsora pachyrhizi Syd. & P. Syd., causal agent of Asian soybean rust. Myclobutanil is known from previous studies in grapevines to be xylem mobile. This study investigates the mobility profile of myclobutanil in soybean as an important component of its effective field performance. RESULTS: Over a 12 day period under greenhouse conditions, a constant uptake of myclobutanil from leaflet surfaces into the leaflet tissue was observed. Once in the leaflet, myclobutanil was seen to redistribute throughout the tissue, although no movement out of leaflets occurred owing to a lack of phloem mobility. The ability of myclobutanil to redistribute over distance within the soybean plant was revealed when visualizing movement of the compound to foliage above the point of application on the plant stem. An efficacy bioassay demonstrated that the systemic properties of myclobutanil allow control of disease at a point remote from the initial site of compound application. CONCLUSION: It is suggested that the high degree of xylem systemicity displayed by myclobutanil in soybean foliage is a contributory factor towards its commercial effectiveness for control of Asian soybean rust. Copyright © 2008 Society of Chemical Industry     

The ACVD task force on canine atopic dermatitis (XV): fundamental concepts in clinical diagnosis.

The clinical signs of atopic dermatitis (AD) in man and in dogs are variable, and there is no single physical or historical feature that, if present, indicates the presence of AD. The initial diagnosis of AD is made clinically with the fulfillment of a combination of criteria that are strongly associated with the disease. Several schemes have been proposed in an attempt to define uniform clinical criteria for diagnosing canine AD, but no system is perfect. Once AD is considered as a possible diagnosis, other important differential diagnoses must be methodically eliminated from consideration. As a final step, once the clinician is certain that AD is probable, "allergy" tests may be conducted to provide additional evidence to "substantiate" the diagnosis. It is important to understand that allergy testing, in whatever form, is not appropriately used early in the patient evaluation as a screening test. Rather, it should be reserved, after a firm clinical diagnosis of AD has been made, to implement allergen avoidance schemes or to select allergens to be incorporated in immunotherapy formulations.     

IgE sensitivity and cross-reactivity to crude and purified mite allergens (Der f 1, Der f 2, Der p 1, Der p 2) in atopic dogs sensitive to Dermatophagoides mite allergens

The present study investigates IgE-reactivity to crude and purified mite allergens by intradermal skin test (IDST), Immunodot method, and ELISA in atopic dogs sensitive to mite allergens, as well as the allergenic cross-reactivity between Dermatophgoides (D) farinae (DF) and D. pteronyssinus (DP) in dogs by IgE-ELISA inhibition. IDST and Immunodot method for crude mite allergens were performed for atopic dogs and 16 atopic dogs showed sensitivity to mite allergens. Of the 16 dogs, all dogs had anti-DF IgE and 11 had anti-DP IgE. We measured specific IgE to purified major allergens (Der f 1, Der f 2, Der p 1, Der p 2). Of the 16 atopic dogs, six had anti-Der f 1 IgE and seven had anti-Der f 2 IgE. Similarly, of the 16 dogs, six had anti-Der p 1 IgE and seven had anti-Der p 2 IgE. However, eight dogs had no specific IgE to these mite allergens. These dogs may be sensitive to other major mite allergens except Der 1 and Der 2. In the dogs that had both anti-DF and DP IgE, IgE binding to DF was greatly inhibited by DP, and reciprocal inhibition was observed. Based on these data, it appears that there is a strong cross-reactivity between DF and DP in dogs. Similarly, a cross-reactivity between DF and DP in purified allergens was also observed. IDST and Immunodot method are useful methods for the diagnosis of atopic diseases in dogs, and ELISA is a useful method for further investigation of IgE-reactivity for the allergens.     

Factors influencing recruitment of walleye and white bass to three distinct early ontogenetic stages

Determining the factors that influence recruitment to sequential ontogenetic stages is critical for understanding recruitment dynamics of fish and for effective management of sportfish, particularly in dynamic and unpredictable environments. We sampled walleye (Sander vitreus) and white bass (Morone chrysops) at 3 ontogenetic stages (age 0 during spring: ‘age‐0 larval’; age 0 during autumn: ‘age‐0 juvenile’; and age 1 during autumn: ‘age‐1 juvenile’) from 3 reservoirs. We developed multiple linear regression models to describe factors influencing age‐0 larval, age‐0 juvenile and age‐1 juvenile walleye and white bass abundance indices. Our models explained 40–80% (68 ± 9%; mean ± SE) and 71%–97% (81 ± 6%) of the variability in catch for walleye and white bass respectively. For walleye, gizzard shad were present in the candidate model sets for all three ontogenetic stages we assessed. For white bass, there was no unifying variable in all three stage‐specific candidate model sets, although walleye abundance was present in two of the three white bass candidate model sets. We were able to determine several factors affecting walleye and white bass year‐class strength at multiple ontogenetic stages; comprehensive analyses of factors influencing recruitment to multiple early ontogenetic stages are seemingly rare in the literature. Our models demonstrate the interdependency among early ontogenetic stages and the complexities involved with sportfish recruitment.     

Evaluation of an agar immunodiffusion procedure for confirming bacterial ring rot diagnoses

Bacterial ring rot-infected tuber and stem tissue reacted withCorynebacterium sepedonicum antiserum in agar immunodiffusion (AID). The AID test was as effective as immunofluorescence (IF) in confirming ring rot in potato tubers submitted for diagnosis. Precipitin bands developed in AID with tuber preparations that contained, in a 1:10 dilution of the preparation, at least 100 IF positive cells/microscope field with a 100 X oil objective. Only a low percentage of preparations with less than 100 IF positive cells were positive with AID. Samples inoculated withC. sepedonicum strains which produced non-mucoid colony types on YGM medium did not consistently develop precipitin bands in AID which suggests that the usefulness of the test may be limited where non-mucoid strains occur naturally.     

Use of induced cutaneous immediate-type hypersensitivity reactions to evaluate anti-inflammatory effects of triamcinolone topical solution in three dogs

The anti-inflammatory effect of a triamcinolone topical solution (TTS) was evaluated by use of induced cutaneous immediate-type hypersensitivity reactions in dogs. Healthy dogs ( n  = 3) were treated on one side of the lateral thorax with TTS, and on the contralateral side with vehicle solution. After 7 days of treatment, serial dilutions of inflammatory stimuli (histamine, compound 48/80, anticanine IgE, substance P, and morphine sulphate) were injected intradermally on both sides. Resulting immediate reactions were subjectively scored, their diameters were measured in millimetres, and microcirculatory blood flow at each site was measured using laser Doppler velocimetry. The magnitude of the differences between TTS and vehicle-treated sides varied with the type of measurement and the stimulus used. With compound 48/80, anti-IgE, substance P, and morphine sulphate-injected sites, for at least one concentration, the reaction scores and sizes were notably less on the TTS-treated sides. Punch skin biopsy specimens were obtained from selected sites 24 h after injection. A pathologist examined stained tissue sections and scored each section as to degree of late-phase dermal cellular infiltrate. Dermal infiltrate scores were generally lower at the TTS-treated sites; the composite score from all TTS-treated sites was 30% lower than that from the vehicle-treated sites. Observations suggest that TTS may be effective in decreasing some aspects of the inflammatory response in canine skin.     

PRELIMINARY EVALUATION OF SURVIVAL AND GROWTH OF JUVENILE RED DRUM (Sciaenops ocellata) IN FRESH AND SALT WATER

Heretofore few quantitative studies on the tolerance of red drum (Sciaenops ocellata Linnaeus) to freshwater (FW) or dilute sea water have been conducted. In the laboratory we subjected larval and juvenile stages of red drum to dechlorinated FW for 96 hours and found 5% survival in larvae (23-day-old, 6.2 mm SL), 70% for postlarvae (34 and 47-day-old, 16.2 mm to 19.7 mm SL) and 95% for juveniles (57-day-old, 56.9 mm SL). Survival in control salinities of 10 ppt was 90% or greater. The results indicate that tolerance to dilute media is size dependent. In a separate experiment growth of juvenile red drum (52 mm SL) over a 30-day period was compared in two raceways with flow-through supplies of dechlorinated FW, and SW of ambient (35±2 ppt) salinity. SW fish grew significantly larger (P < .01) than those acclimated to FW. Within both treatments a large size differential developed with time. Food conversion efficiency was improved and appetite drive was enhanced in the SW treatment. Percent survival after 30 days was comparably high (93%) in both treatments. Fast growth and high survival of juvenile (>20 mm SL) red drum promote the feasibility of this valuable sport and commercial species in both FW and SW aquaculture. Its potential as a control fish in FW fishery management deserves further investigation.     

An investigation of skin temperature differentials in relation to estrus in dairy cattle using a thermal infrared scanning technique

To evaluate the effectiveness of thermal infrared scanning as a technique to detect estrus, 27 Holstein-Friesian cows were observed for a 90-d period beginning in the second week postpartum. The area enclosed by the 37-C isotherm on the gluteal region of a cow's body tended to increase in association with the occurrence of estrus. This increase became statistically significant at the third postpartum estrus. During the first 50-postpartum d, infrared scanning enhanced detection of estrus when compared with standard dairyman-detection accuracy. However, detection of estrus using infrared scanning was hampered by false positives (33% around the third postpartum estrus) and inability to detect estrus for some cows (7%). It appears at present that the usefulness of infrared scanning for routine detection of estrus in dairy cows is limited, but the technique may have potential as a research tool for the study of skin temperature patterns.     

Serum allergen‐specific immunoglobulin E in atopic and healthy cats: comparison of a rapid screening immunoassay and complete‐panel analysis

Feline and canine atopic dermatitis are thought to have a similar immunopathogenesis. As with dogs, detection of allergen‐specific IgE in cat serum merely supports a diagnosis of feline atopy based on compatible history, clinical signs and elimination of other pruritic dermatoses. In this study, a rapid screening immunoassay (Allercept^® E‐Screen 2nd Generation; Heska AG, Fribourg, Switzerland; ES2G) was compared with a complete‐panel serum allergen‐specific IgE assay (Allercept^®; Heska AG; CP) in healthy cats with no history of skin disease and in atopic cats. The latter had no diagnosis of external parasitism, infection, food hypersensitivity or other skin disease explaining their pruritus, and expressed cutaneous reaction patterns typically associated with feline allergic skin disease (head, neck or pinnal pruritus, miliary dermatitis, self‐induced alopecia, eosinophilic granuloma complex). The proportion of cats positive on either the ES2G or the CP assays was not significantly different between the atopic and healthy cat groups. There was, however, strong agreement between the results of the ES2G and CP assay; overall, the two tests were in agreement for 43 of 49 (88%) serum samples. There was also strong agreement when individual allergen groups were evaluated (agreement noted: indoor, 41 of 49 samples; grasses/weeds, 37 of 49 samples; and trees, 41 of 49 samples). These results indicate that although neither test is diagnostic for feline atopic dermatitis, the screening assay is beneficial for predicting the results of a complete‐panel serum allergen‐specific IgE assay in cats.