Staphylococcal enterotoxin B causes proliferation of sensory C-fibers and subsequent enhancement of neurogenic inflammation in rat skin.

BACKGROUND: Staphylococcal enterotoxin B (SEB) may be associated with the exacerbation of atopic dermatitis. We investigated whether SEB causes proliferation of sensory C-fibers and subsequent enhancement of plasma leakage induced by sensorineural stimulation in rat skin. METHODS: SEB was applied intracutaneously to the abdomen of preweaning and adult rats. Evans blue dye leakage into the skin induced by topical 10% formalin was measured as an index of neurogenic skin vascular permeability. Local expression of substance P, tachykinin NK1 receptors, and nerve growth factor was assessed immunohistochemically. In addition, we assessed the effects of topical tacrolimus on these skin responses induced by SEB. RESULTS: Increased neurogenic skin plasma leakage was seen 7 days after SEB treatment in 2 different age groups. Innervation of substance P-immunoreactive nerves and expression of tachykinin NK1 receptors and nerve growth factor were also promoted by SEB, peaking at 7 days, 7 days, and 56 h after SEB treatment, respectively. Tacrolimus markedly inhibited these skin changes. CONCLUSIONS: SEB increased the innervation of sensory C-fibers and tachykinin NK1 receptors in rat skin, probably because of upregulated production of neurotrophins, including nerve growth factor, leading to enhancement of neurogenic skin inflammation. T cell activation induced by SEB may initiate these changes.

Development of mechanisms associated with neurogenic-mediated skin inflammation during the growth of rats.

Neurogenic-mediated inflammation may be associated with several inflammatory skin diseases including atopic dermatitis. However, age-dependent differences in neurogenic-mediated skin responses are not fully understood. We compared skin plasma leakage in rats aged 2 and 8 wk, which was induced by topical capsaicin, topical formalin, and intracutaneous substance P, whose effects are mediated via tachykinin NK1 receptors. Evans blue dye extravasation served as an index of the increase in skin vascular permeability. Capsaicin, formalin, and substance P caused a skin response in a dose-dependent manner in both age groups. However, the skin response was much greater in adults than in pups. In addition, the localization of sensory C-fibers and tachykinin NK1 receptors in the skin was investigated by immunofluorescent staining with antisubstance P and antitachykinin NK1 receptor antibodies, respectively. Substance P-immunoreactive nerves were detected throughout the dermis and tachykinin NK1 receptors were mainly detected in blood vessel walls in the dermis in both age groups. However, they were more sparsely distributed in pups. In conclusion, the weak neurogenic-mediated skin inflammation in pups is probably because of immature neural mechanisms associated with skin inflammation such as reduced innervation of sensory C-fibers and low expression of tachykinin NK1 receptors.

Allergic bronchopulmonary aspergillosis in a 2-year-old asthmatic boy with immune dysregulation, polyendocrinopathy, enteropathy, X-linked.

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) is caused by impaired function of CD4(+)CD25(+) regulatory T cells that play an important role in controlling exaggerated Th2 responses. The pathogenesis of allergic bronchopulmonary aspergillosis (ABPA) appears to be closely associated with the Th2 response. We report the first case of ABPA in a 2-year-old asthmatic boy with IPEX, this being an unusually young age for the development of ABPA.

[Improved capability of a revised test kit, FASTKIT ELISA version II (Egg), to detect heated proteins of egg white but not egg yolk].

BACKGROUND: A kit, FASTKIT ELISA version II (Egg) (Nippon Meat Packers) is an enzyme-linked immunosorbent assay kit for detecting hen's egg proteins in foodstuffs. This kit is an enhanced version of FASTKIT ELISA (Egg) with a greater efficiency in terms of extraction of egg proteins from heated foodstuffs. However, the property of this kit remains to be fully elucidated. METHODS: Using this new kit, we measured the amount of egg proteins in unheated or heated (140 degrees C or 180 degrees C, 20 min) homemade cookies containing whole egg, egg white or egg yolk. RESULTS: The capability for detection of unheated or heated (140 degrees C or 180 degrees C) whole egg proteins was similar. In addition, there was no significant difference in the detectability between heated (140 degrees C) whole egg and egg white proteins. However, unheated or heated (140 degrees C or 180 degrees C) egg yolk proteins were not sufficiently measured by this kit. CONCLUSION: Our data suggest that this new kit is significantly improved for detection of heated egg white proteins as compared to that of old version, but not sufficient for detection of egg yolk proteins.