Effect of recombinant canine IFNγ on canine atopic dermatitis evaluated by clinical signs,histopathology and expression of Th1/Th2 cytokine mRNA

Atopic dermatitis (AD) is thought to be caused by immunologic abnormalities expressed as a Th1/Th2 cytokine imbalance in both humans and dogs. Several studies have focused on the therapeutic effects of IFNγ in human AD with successful results; however, the mechanism of action of IFNγ is not fully understood. We investigated the effect of recombinant canine interferon gamma (rCaIFNγ) on 10 dogs with AD and evaluated the ratio of IL‐4 mRNA to IFNγ mRNA in peripheral blood mononuclear cells, serum total IgE levels, and histological changes in skin. After six injections of rCaIFNγ over a span of 2 weeks, seven of the 10 dogs showed improvement, and six of these seven dogs exhibited decreased IL‐4:IFNγ mRNA ratios. Two of the three cases that did not improve had increased IL‐4:IFNγ mRNA ratios. Total serum IgE levels were significantly decreased in nine of 10 cases. The number of IgE‐positive cells detected by immunostaining and the number of mast cells in skin biopsy samples were decreased. A reduction of epidermal cell layers was demonstrated by histopathology after treatment. These results demonstrated that rCaIFNγ may be a novel safe and effective therapeutic option for the treatment of canine AD, and the mechanism of action of rCaIFNγ may be related to the modulation of Th2 cytokines to Th1 cytokines with the reduction of serum IgE production. Funding: Self‐funded.     

FC‐51 Comparison of intradermal test and antigen‐specific IgE test in 22 cases of feline allergic dermatitis

The usefulness of the intradermal test (IDT) and the serological allergy test (SAT) for detecting antigen‐specific IgE in allergic cats has not yet been established. In this study, we compared the results of IDT with those of SAT and evaluated the clinical usefulness of the two tests for detecting possible allergens in allergic cats. IDT and SAT using eight antigens were performed on 22 cats with intense pruritus after excluding ectoparasites and performing diet elimination tests. Approximately 50% of the cats reacted to at least one allergen by either IDT or SAT, and 36.4% of the cats reacted on both IDT and SAT. In contrast, seven healthy cats did not show any reactions on IDT or SAT. The most commonly detected allergen in both tests was house dust mites (IDT, 36.4%; SAT, 40.9%). Five cats reacted to one allergen and the others reacted to more than one allergen with IDT. Three cats reacted to one allergen with SAT. The following percentage agreement between the results of the two tests was calculated: house dust mites (86.4%), cat fleas (63.6%), grass mix (86.4%), common mugwort (81.8%), cat epithelia (90.9%), ragweed (86.4%), Japanese cedar (90.9%), and plantain (81.8%). The overall mean percentage agreement was 83.5%. In summary, the present study showed good agreement between IDT and SAT for cats, and SAT may be more sensitive than IDT, but less specific for detecting sensitized allergens. Funding: Self‐funded.     

Pseudorabies virus infection in hunting dogs in Oita,Japan: Report from a prefecture free from Aujeszky’s disease in domestic pigs

We isolated two pseudorabies virus (PRV) isolates (designated OT-1 and OT-2) from two hunting dogs exhibiting neurological manifestations after eating the flesh of wild boar hunted in Oita prefecture, Kyushu Island, Japan. The isolates corresponded to a previously reported PRV (MY-1 strain) isolated from a hunting dog in neighboring Miyazaki prefecture, and it clustered into genotype II based on the glycoprotein C sequence. Our results suggest that this common PRV strain may have been maintained in wild boars on Kyushu Island even though domestic pigs in this area have attained an Aujeszky’s disease-free status.     

Cyclosporine A inhibits the mRNA expressions of IL-2, IL-4 and IFN-gamma, but not TNF-alpha, in canine mononuclear cells

The effects of the calcineurin inhibitors cyclosporine A (CsA) and FK506 on the mRNA expressions of various cytokines were evaluated in dogs to determine whether the effects of CsA and FK506 in dogs were similar to those in humans. The mRNA expression levels of the cytokines IL-2, IL-4, IFN-gamma and TNF-alpha were measured in PHA-stimulated canine PBMC using real-time RT-PCR after incubation with CsA or FK506 for 5 hr. Both reagents inhibited IL-2, IL-4 and IFN-gamma mRNA expressions in a dose-dependent manner. However, CsA hardly inhibited the mRNA expression of TNF-alpha. These findings are important for assessing the indications of CsA treatment in dogs.     

A case of hyperplastic dermatosis of the West Highland White Terrier controlled by recombinant canine interferon-gamma therapy

A 3.5-year-old, male West Highland White Terrier was diagnosed as having hyperplastic dermatosis by clinical and histopathological findings. Controlling of Malassezia overgrowth by antifungal drugs provided a temporal improvement of the skin lesions, but the disease was deteriorated within the next 2 months despite the negative demonstration of the yeasts. Induction of recombinant canine interferon-gamma (rCaIFN-gamma) therapy resulted in almost complete cure of the skin lesions within 2 months after the initiation of the therapy. No adverse effects were detected during the therapy. Our results suggested that the rCaIFN-gamma therapy is potential to be a novel therapeutic option for controlling the breed-specific hyperplastic skin disease.     

A novel culture method of canine peripheral blood lymphocytes with concanavalin a and recombinant human interleukin-2 for adoptive immunotherapy

This study was designed to develop a novel culture method for the efficient proliferation of canine peripheral blood lymphocytes (cPBL) for adoptive immunotherapy. When cPBL were cultured in the presence of concanavalin A (Con A), proliferation of cPBL was induced and expression of interleukin-2 receptor (IL-2R) which enables to respond to exogenously added IL-2 was upregulated. And then, when cPBL were cultured with recombinant human interleukin-2 (rhIL-2) in addition to Con A, proliferation was accelerated and increased to about 10-fold after 1 week. The phenotypic analysis showed that the main population of the cultured cPBL was consisted of CD8+ positive lymphocytes. Among them, CD4+CD8+ double positive (DP) lymphocytes had significantly increased, and the ratio of CD4+ single positive (SP) lymphocytes to CD8+ SP lymphocytes (CD4+SP/CD8+SP) was decreased as compared to before culturing. To evaluate the cytotoxic activity of cPBL cultured with Con A and rhIL-2, furthermore, cytotoxic assay was carried out against xenogeneic melanoma cell line (MeWo), which resulted in MHC-unrestricted cytokilling. These results suggest that the culture method of cPBL by the use of Con A and rhIL-2 may be useful for generating lymphokine activated killer cells, and also this may be beneficial for adoptive immunotherapy of tumor-bearing dogs.     

Papaya seed represents a rich source of biologically active isothiocyanate

In the present study, papaya (Carica papaya) seed and edible pulp were carefully separated and then the contents of benzyl isothiocyanate and the corresponding glucosinolate (benzyl glucosinolate, glucotropaeolin) quantified in each part. The papaya seed with myrosinase inactivation contained >1 mmol of benzyl glucosinolate in 100 g of fresh seed. This content is equivalent to that of Karami daikon (the hottest Japanese white radish) or that of cress. The papaya seed extract also showed a very high activity of myrosinase and, without myrosinase inactivation, produced 460 micromol of benzyl isothiocyanate in 100 g of seed. In contrast, papaya pulp contained an undetectable amount of benzyl glucosinolate and showed no significant myrosinase activity. The n-hexane extract of the papaya seed homogenate was highly effective in inhibiting superoxide generation and apoptosis induction in HL-60 cells, the activities of which are comparable to those of authentic benzyl isothiocyanate.     

Effects of Calcium Lactate on the Development of Chicken Embryos in a Shell-less Culture System up to Day Seventeen of Incubation

This study examined the effects of calcium lactate on the development of chicken embryos in a shell-less culture system (cSLCS) up to the seventeenth day of incubation. In the presence of calcium lactate, a significant reduction in embryo viability was observed during the first week of incubation in cSLCS. On day 17 of embryo development, no significant difference was observed in the blood plasma calcium concentration or tibia bone density between cSLCS and intact control embryos, whereas the tibia length was significantly shorter in cSLCS embryos than in the intact control. These results suggest that calcium lactate supplementation in cSLCS supports bone formation in developing chicken embryos, but has adverse effects on the viability of embryos, particularly during the first week of embryo development.     

Effects of Nitrogen Forms on Carbon and Nitrogen Accumulation in Tomato Seedling

Utilization of organic nitrogen （N） is an important aspect of plant N assimilation and has potential application in sustainable agriculture. The aim of this study was to investigate the plant growth, C and N accumulation in leaves and roots of tomato seedlings in response to inorganic （NH4^＋-N, NO3^-N） and organic nitrogen （Gly-N）. Different forms of nitrogen （NH4^＋-N, NO3^--N, Gly-N） were supplied to two tomato cultivars （Shenfen 918 and Huying 932） using a hydroponics system. The plant dry biomass, chlorophyll content, root activity, total carbon and nitrogen content in roots and leaves, and total N absorption, etc. were assayed during the cultivation. Our results showed that no significant differences in plant height, dry biomass, and total N content were found within the first 16 d among three treatments; however, significant differences in treatments on 24 d and 32 d were observed, and the order was NO3^--N 〉 Gly-N 〉 NH4^＋-N. Significant differences were also observed between the two tomato cultivars. Chlorophyll contents in the two cultivars were significantly increased by the Gly-N treatment, and root activity showed a significant decrease in NHa^＋-N treatment. Tomato leaf total carbon content was slightly affected by different N forms; however, total carbon in root and total nitrogen in root and leaf were promoted significantly by inorganic and organic N. Among the applied N forms, the increasing effects of the NH4^＋-N treatment were larger than that of the Gly-N. In a word, different N resources resulted in different physiological effects in tomatoes. Organic nitrogen （e.g., Gly-N） can be a proper resource of plant N nutrition. Tomatoes of different genotypes had different responses under organic nitrogen （e.g., Gly-N） supplies.