Takanori Taogoshi

Common food allergens and their IgE-binding epitopes

Food allergy is an adverse immune response to certain kinds of food. Although any food can cause allergic reactions, chicken egg, cows milk, wheat, shellfish, fruit, and buckwheat account for 75% of food allergies in Japan. Allergen-specific immunoglobulin E (IgE) antibodies play a pivotal role in the development of food allergy. Recent advances in molecular biological techniques have enabled the efficient analysis of food allergens. As a result, many food allergens have been identified, and their molecular structure and IgE-binding epitopes have also been identified. Studies of allergens have demonstrated that IgE antibodies specific to allergen components and/or the peptide epitopes are good indicators for the identification of patients with food allergy, prediction of clinical severity and development of tolerance. In this review, we summarize our current knowledge regarding the allergens and IgE epitopes in the well-researched allergies to chicken egg, cows milk, wheat, shrimp, and peanut.

Transport of prostaglandin E1 across the blood-brain barrier in rats

The transport of prostaglandin E1 (PGE1) across the blood‐brain barrier (BBB) was characterized using an in‐situ rat brain perfusion technique. The uptake of [3H]PGE1 was not affected by short‐chain monocarboxylic acids (butyric acid and valeric acid). On the other hand, uptake of [3H]PGE1 was significantly inhibited by medium‐chain monocarboxylic acids such as hexanoic acid, enanthic acid and octanoic acid. These medium‐chain monocarboxylic acids showed a more potent inhibitory effect on [3H]PGE1 uptake with increasing number of carbon atoms. In contrast, there was no decrease in [3H]PGE1 transport by any dicarboxylic acids with 5–8 carbon atoms. Valproic acid decreased [3H]PGE1 uptake, whereas p‐aminohippuric acid, a substrate for the organic anion transporter family, did not inhibit [3H]PGE1 transport. Bromocresol green, an inhibitor of prostaglandin transporter (PGT), strongly decreased [3H]PGE1 transport across the BBB. In addition, digoxin and taurocholate, substrates for organic anion transporting polypeptide subtype 2 (Oatp2), significantly inhibited [3H]PGE1 uptake. RT‐PCR analysis revealed that PGT mRNA and Oatp2 mRNA are expressed in a capillary‐rich fraction from rat brain. Thus, it is suggested that PGE1 transport across the BBB is mediated by some specific transport systems, possibly by the members of the Oatp family.

Injury due to extravasation of thiopental and propofol: Risks/effects of local cooling/warming in rats

Inadvertent leakage of medications with vesicant properties can cause severe necrosis in tissue, which can have devastating long-term consequences. The aim of this study was to evaluate the extent of extravasation injury induced by thiopental and propofol, and the effects of cooling or warming of local tissue on extravasation injury at macroscopic and histopathologic levels. Rats were administered intradermally thiopental (2.5 mg/100 µL) or propofol (1.0 mg/100 µL). Rats were assigned randomly to three groups: control (no treatment), cooling and warming. Local cooling (18–20 °C) or warming (40–42 °C) was applied for 3 h immediately after agent injection. Lesion sizes (erythema, induration, ulceration, necrosis) were monitored after agent injection. Histopathology was evaluated in skin biopsies taken 24 h after agent injection. Thiopental injection induced severe skin injury with necrosis. Peak lesions developed within 24 h and healed gradually 18–27 days after extravasation. Propofol induced inflammation but no ulceration, and lesions healed within 1–2 days. Local cooling reduced thiopental- and propofol-induced extravasation injuries but warming strongly exacerbated the skin lesions (e.g., degeneration, necrosis) induced by extravasation of thiopental and propofol. Thiopental can be classified as a “vesicant” that causes tissue necrosis and propofol can be classified as an “irritant”. Local cooling protects (at least in part) against skin disorders induced by thiopental and propofol, whereas warming is harmful.

Partial characterization of proapoptotic action of biliary deteriorated lipids on biliary epithelial cells in pancreaticobiliary diseases

Lysophosphatidylcholine (LPC), a derivative of phosphatidylcholine (PC) hydrolyzed by phospholipase A2 (PLA2), is reported to be increased in bile of the patients with pancreaticobiliary maljunction or intrahepatic cholelithiasis, both of which are major risk factors for biliary tract cancers with undefined etiology.

Quantification of the ω5- and γ-gliadin content in wheat flour and rat plasma with an enzyme-linked immunosorbent assay using antibodies specific to their IgE-binding epitopes

This work was supported in part by a Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science, and Technology, Japan (No. 16K08371).

Stability of Adrenaline in Irrigating Solution for Intraocular Surgery

Intraocular irrigating solution containing 1 µg/mL adrenaline is widely used during cataract surgery to maintain pupil dilation. Prepared intraocular irrigating solutions are recommended for use within 6 h. After the irrigating solution is admistered for dilution, the adrenaline may become oxidized, and this may result in a decrease in its biological activity. However, the stability of adrenaline in intraocular irrigating solution is not fully understood. The aim of this study was to evaluate the stability of adrenaline in clinically used irrigating solutions of varying pH. Six hours after mixing, the adrenaline percentages remaining were 90.6%±3.7 (pH 7.2), 91.1%±2.2 (pH 7.5), and 65.2%±2.8 (pH 8.0) of the initial concentration. One hour after mixing, the percentages remaining were 97.6%±2.0 (pH 7.2), 97.4%±2.7 (pH 7.5), and 95.6%±3.3 (pH 8.0). The degradation was especially remarkable and time dependent in the solution at pH 8.0. These results indicate that the concentration of adrenaline is decreased after preparation. Moreover, we investigated the influence of sodium bisulfite on adrenaline stability in irrigating solution. The percentage adrenaline remaining at 6 h after mixing in irrigating solution (pH 8.0) containing sodium bisulfite at 0.5 µg/mL (concentration in irrigating solution) or at 500 µg/mL (concentration in the undiluted adrenaline preparation) were 57.5 and 97.3%, respectively. Therefore, the low concentration of sodium bisulfite in the irrigating solution may be a cause of the adrenaline loss. In conclusion, intraocular irrigation solution with adrenaline should be prepared just prior to its use in surgery.