Evaluation of a Novel Detection Method for Allergen-Specific IgE Antibodies with IgE Receptor Crosslinking Using Rat Food Allergy Model.

The specific detection of serum IgE antibodies specific to allergens (sIgE Abs) that can crosslink the plural high-affinity IgE receptor (FcεRIα) molecules on the surface of mast cells or basophils with a multivalent allergen can reduce the false-positive diagnoses observed in chemiluminescent and fluorescence enzyme immunoassays for type-I allergic patients. In this study, we detected sIgE Abs to the egg-allergen ovalbumin (OVA) and the wheat-allergen gluten in the sera of rats sensitized with each allergen using an amplified luminescence proximity homogeneous assay by crosslinking (AlphaCL). OVA and gluten were reacted with each sIgE Ab in the sera. Then, acceptor and donor beads labeled with the human FcεRIα were added to the reacted solution. The luminescence intensity for anti-OVA IgE Abs in the sera with the removal of IgG Abs was observed in five of seven (71.4%) of the sensitized rats, whereas no signals were observed in any of the unsensitized rats. The AlphaCL could also detect anti-gluten sIgE Abs in the sera of sensitized rats, but not of unsensitized rats. In conclusion, we successfully detected sIgE Abs in the sera of rats sensitized to two allergens using the AlphaCL. This detection method has the potential to be used as a new diagnostic tool for type-I allergic patients.

Assessment of the Safety of Exposure to Cefcapene Pivoxil during the First Trimester of Pregnancy: A Prospective Cohort Study in Japan.

Cefcapene pivoxil hydrochloride is an antibiotic often used by women who are or may be pregnant. However, the safety of exposure to it during the first trimester of pregnancy has not been assessed. In this study, we aimed to clarify the effects of exposure during the first trimester of pregnancy on maternal and fetal outcomes. Data were obtained from pregnant women who were counseled on drug use during pregnancy at two Japanese facilities from April 1988 to December 2017. The incidence of major malformations in singleton pregnancy was compared between neonates born to women who took cefcapene pivoxil hydrochloride (n = 270) and control drugs (n = 1594) during their first trimester. The adjusted odds ratio of the incidence of major malformations was calculated using multivariate logistic regression analysis adjusted for smoking during pregnancy and maternal age. The incidence of major malformations was 2.6% in the cefcapene pivoxil hydrochloride group and 1.8% in the control group. There were no significant differences in the incidence between the cefcapene pivoxil hydrochloride and control groups (adjusted odds ratio: 1.48 [95% confidence interval: 0.64-3.42], p = 0.36). This prospective cohort study showed that exposure to cefcapene pivoxil hydrochloride during the first trimester of pregnancy was not associated with increased risk of major malformations in infants. Our findings will help healthcare providers in choosing appropriate medicines.

Comparison of Berberine Bioavailability between Oral and Rectal Administrations in Rats.

The oral bioavailability of berberine is quite low due to extensive first-pass metabolism. To increase the bioavailability of berberine (BBR), the efficacy of rectal administration that can avoid intestinal and hepatic first-pass metabolism partly was evaluated using BBR sulfate in rats. BBR sulfate was administered intravenously (1 mg/kg as BBR), orally (10 mg/kg as BBR) and rectally (1, 3, or 10 mg/kg as BBR) using Witepsol® H15 suppository base to evaluate bioavailability in rats. Concentrations of BBR in plasma were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). When BBR sulfate was administered orally, the average oral bioavailability was 0.26%. When BBR sulfate was administered rectally, the average bioavailabilities were 17.0% at 1 mg/kg, 24.3% at 3 mg/kg, and 12.3% at 10 mg/kg as BBR, respectively. Thus, rectal administration of BBR sulfate greatly increased the bioavailability of BBR as compared with oral administration, which would also increase the pharmacological activities of BBR in vivo.

A novel test for type-I allergy based on crosslink formation of immunoglobulin-E receptors by allergen-specific immunoglobulin-E antibodies and an allergen.

Detection of allergen-specific immunoglobulin E (IgE) antibodies (Abs) in serum would allow for screening of the causative allergen in patients with type-I allergy. In this study, we developed a new assay method to detect allergen-specific IgE Abs, which involved crosslinking the plural FcεRIα molecules with an allergen and detection using an amplified luminescence proximity homogeneous assay (AlphaCL). First, the allergen concentration, bead concentrations, and incubation time were optimized for the detection of anti-2,4-dinitrophenyl (DNP) IgE Abs in buffer. Under optimal conditions, AlphaCL was able to detect DNP-specific IgE Abs in simulated human serum at levels comparable to those in serum from type-I allergic patients. When AlphaCL was used to detect anti-DNP IgE Abs, no signal counts were obtained with the monovalent allergen 2,4-dinitrophenylated poly-γ-glutamic acid, whereas high signal counts were obtained with the multivalent allergen DNP-BSA. This confirmed that AlphaCL could specifically detect allergen-specific IgE Abs with the ability to crosslink a multivalent allergen. In summary, we have established a new assay model using AlphaCL to detect allergen-specific IgE Abs with FcεRIα crosslinking ability in human serum. This simple and practical assay model may be applied as a new diagnostic tool for patients with type-I allergy.

A Narrative Mini Review on Current Status of Hypoallergenic Wheat Development for IgE-Mediated Wheat Allergy, Wheat-Dependent Exercise-Induced Anaphylaxis.

Immunoglobulin E (IgE)-mediated food allergies to wheat that develop after school age typically shows a type of wheat-dependent exercise-induced anaphylaxis (WDEIA). At present, avoidance of wheat products or postprandial rest after ingesting wheat is recommended for patients with WDEIA, depending on the severity of the allergy symptoms. ω5-Gliadin has been identified as the major allergen in WDEIA. In addition, α/ß-, γ-, and ω1,2-gliadins, high and low molecular weight-glutenins, and a few water-soluble wheat proteins have been identified as IgE-binding allergens in a small proportion of patients with IgE-mediated wheat allergies. A variety of approaches have been manufactured to develop hypoallergenic wheat products that can be consumed by patients with IgE-mediated wheat allergies. In order to analyze such approaches, and to contribute to the further improvement, this study outlined the current status of these hypoallergenic wheat productions, including wheat lines with a reduced allergenicity that are mostly constructed for the patients sensitized to ω5-gliadin, hypoallergenic wheat by enzymic degradation/ion exchanger deamidation, and hypoallergenic wheat by thioredoxin treatment. The wheat products obtained by these approaches significantly reduced the reactivity of Serum IgE in wheat-allergic patients. However, either these were not effective on some populations of the patients, or low-level IgE-reactivity to some allergens of the products was observed in the patients. These results highlight some of the difficulties faced in creating hypoallergenic wheat products or hypoallergenic wheat lines through either traditional breeding or biotechnology approaches in developing hypoallergenic wheat completely safe for all the patients allergic to wheat.

Classification of Skin Injury Risk Caused by Extravasation of Electrolyte Solutions or Infusions in a Rat Model.

Cytotoxic agents are classified according to the severity of skin injury after extravasation. However, injuries caused by extravasation of noncytotoxic agents have not been sufficiently investigated, although the risk of extravasation is mentioned in medical safety information published by the Japan Council for Quality Health Care. Therefore, in this study, we focused on noncytotoxic electrolyte solutions and infusions and evaluated skin injuries during leakage using extravasation model rats. Rats were anesthetized and intradermally injected with 100 µL of an electrolyte solution or infusion. Injection lesions were macroscopically and histopathologically evaluated for extravasation injuries. Each electrolyte solution and infusion were classified into three categories (vesicants, irritants, and non-tissue-damaging agents) depending on the degree of skin injury. Similar to saline, 0.3% potassium chloride and 0.6% magnesium sulfate showed almost no injury, and 3% sodium chloride and BFLUID® caused erythema and induration. Erythema, induration, and ulceration were observed with the following: 10% sodium chloride, 2% calcium chloride, 8.5% calcium gluconate, 12.3% magnesium sulfate, MAGSENT®, FESIN®, and Intralipos®. The duration of damage with these agents was markedly prolonged. Electrolyte solutions and infusions can be classified into vesicants (10% sodium chloride, 2% calcium chloride, 8.5% calcium gluconate, 12.3% magnesium sulfate, MAGSENT®, FESIN®, and Intralipos®), irritants (3% sodium chloride and BFLUID®), and non-tissue-damaging agents (0.3% potassium chloride and 0.6% magnesium sulfate) according to their composition. The characteristic symptoms and severity of each drug extravasation revealed in this study will provide basic information for preparation of guidelines for treatment of extravasation.

Hypoallergenic Wheat Line (1BS-18H) Lacking ω5-Gliadin Induces Oral Tolerance to Wheat Gluten Proteins in a Rat Model of Wheat Allergy.

The early ingestion of food can prevent the onset of food allergy related to inducing oral tolerance (OT). We developed the Hokushin wheat line as a hypoallergenic wheat (1BS-18H) lacking ω5-gliadin, a major allergen of wheat-dependent exercise-induced anaphylaxis (WDEIA). The 1BS-18H wheat had lower ability of sensitization for ω5-gliadin compared with Hokushin wheat. Here, we evaluated the induction of OT to gluten and ω5-gliadin by the early consecutive ingestion of 1BS-18H gluten using a rat model of wheat allergy. Rats were subcutaneously immunized with commercial gluten or native ω5-gliadin following the daily oral administration of gluten. The daily oral administration of 1BS-18H gluten for 5 days before immunization suppressed the increase in gluten- or ω5-gliadin-specific IgE and IgG1 antibodies induced by immunization to a level similar to Hokushin gluten. Intravenous challenge with gluten or ω5-gliadin did not decrease the rectal temperature in rats with OT induced by 1BS-18H or Hokushin gluten, although it was decreased in non-OT rats. In conclusion, the early consecutive ingestion of 1BS-18H wheat before sensitization induced OT to gluten and ω5-gliadin. These findings support the benefit of 1BS-18H wheat to prevent wheat allergy including WDEIA by consecutive ingestion in humans.

Emerging Anti-Inflammatory Pharmacotherapy and Cell-Based Therapy for Lymphedema.

Secondary lymphedema is a common complication of lymph node dissection or radiation therapy for cancer treatment. Conventional therapies such as compression sleeve therapy, complete decongestive physiotherapy, and surgical therapies decrease edema; however, they are not curative because they cannot modulate the pathophysiology of lymphedema. Recent advances reveal that the activation and accumulation of CD4+ T cells are key in the development of lymphedema. Based on this pathophysiology, the efficacy of pharmacotherapy (tacrolimus, anti-IL-4/IL-13 antibody, or fingolimod) and cell-based therapy for lymphedema has been demonstrated in animal models and pilot studies. In addition, mesenchymal stem/stromal cells (MSCs) have attracted attention as candidates for cell-based lymphedema therapy because they improve symptoms and decrease edema volume in the long term with no serious adverse effects in pilot studies. Furthermore, MSC transplantation promotes functional lymphatic regeneration and improves the microenvironment in animal models. In this review, we focus on inflammatory cells involved in the pathogenesis of lymphedema and discuss the efficacy and challenges of pharmacotherapy and cell-based therapies for lymphedema.

A novel detection method for cross-linking of IgE-receptors by autoantibodies in chronic spontaneous urticaria.

BACKGROUND: Autoantibodies (AAbs) against immunoglobulin E (IgE) antibodies (Abs) and their high-affinity receptor alpha subunits (FcεRIα) are key factors in the elicitation of type IIb autoimmune chronic spontaneous urticaria (type IIb aiCSU). In this study, we aimed to develop a new method to detect functional anti-FcεRIα and anti-IgE AAbs, which can crosslink the plural FcεRІα molecules and IgE Abs on the surface of mast cells and basophils, in sera from aiCSU patients using the amplified luminescence proximity homogeneous assay (Alpha). METHODS: Sera were obtained from 14 aiCSU patients, as diagnosed by recurrent chronic spontaneous urticaria episodes and positive results for the autologous serum skin test and/or histamine release test (HRT). The AAbs to FcεRIα and IgE Abs were determined in sera from aiCSU patients using enzyme-linked immunosorbent assay (ELISA) and Alpha by cross-linking (AlphaCL) of IgE Abs and/or FcεRІα. RESULTS: Serum anti-FcεRIα and anti-IgE AAb levels were not significantly different between aiCSU patients and healthy subjects in ELISA. Anti-FcεRIα AAbs were detected in 10 of 14 aiCSU patients who displayed positive (5/5) and negative (5/9) results in the HRT for anti-FcεRIα AAbs by AlphaCL, whereas no signals were observed in healthy subjects. Additionally, anti-IgE AAbs were detected in two of four aiCSU patients who displayed positive results in the HRT for anti-IgE AAbs. CONCLUSIONS: A new assay method using AlphaCL can detect anti-FcεRIα and anti-IgE AAbs with FcεRIα- and IgE-crosslinking abilities in sera from aiCSU patients. This simple and practical assay method may be available as a diagnostic tool for urticaria patients.

Identification of allergens for food-dependent exercise-induced anaphylaxis to shrimp.

Shrimp is a causative food that elicits food-dependent exercise-induced anaphylaxis (FDEIA). In this study, we sought to identify IgE-binding allergens in patients with shrimp-FDEIA. Sera were obtained from eight patients with shrimp-FDEIA and two healthy control subjects. Proteins were extracted from four shrimp species by homogenization in Tris buffer. Immunoblot analysis revealed that IgE from patient sera bound strongly to a 70-kDa and a 43-kDa protein in a preparation of Tris-soluble extracts from Litopenaeus vannamei. Mass spectrometry identified the 70-kDa and 43-kDa proteins as a P75 homologue and fructose 1,6-bisphosphate aldolase (FBPA), respectively. To confirm that the putative shrimp allergens were specifically recognized by serum IgE from shrimp-FDEIA patients, the two proteins were purified by ammonium sulfate precipitation followed by reversed-phase HPLC and/or anion-exchange hydrophobic interaction chromatography and then subjected to immunoblot analysis. Purified P75 homologue and FBPA were positively bound by serum IgE from one and three, respectively, of the eight patients with shrimp-FDEIA, but not by sera from control subjects. Thus, P75 homologue and FBPA are identified as IgE-binding allergens for shrimp-FDEIA. These findings could be useful for the development of diagnostic tools and desensitization therapy for shrimp-FDEIA patients.

Identification of peroxidase-1 and beta-glucosidase as cross-reactive wheat allergens in grass pollen-related wheat allergy.

BACKGROUND: Some patients with wheat-dependent exercise-induced anaphylaxis (WDEIA) or wheat allergy showed negative ω-5 gliadin-specific IgE test and high level of grass pollen-specific IgE. It was presumed that these patients developed allergic reaction upon cross-reaction of their IgE antibodies raised against grass pollen allergens to wheat allergens. This study aimed to clarify clinical characteristics and wheat allergens of this phenotype of WDEIA/wheat allergy, which were tentatively diagnosed as grass pollen-related wheat allergy (GPWA). METHODS: A total of six patients with GPWA were enrolled, and controls were 17 patients with grass pollen allergy but no episode of wheat allergy, and 29 patients with other wheat allergies: 18 with conventional WDEIA and 11 with hydrolyzed wheat protein allergy. Sensitization to wheat proteins was determined by basophil activation test (BAT). IgE-binding proteins in wheat flour were identified by immunoblotting followed by mass spectrometry. Wheat allergen-specific IgE tests were established by CAP-FEIA system. RESULTS: All the six patients with GPWA were sensitized to water-soluble wheat proteins in BAT and IgE-immunoblotting, and peroxidase-1 (35 kDa) and beta-glucosidase (60 kDa) were identified as specific IgE-binding wheat proteins. The binding of patient IgE to these proteins was inhibited by pre-incubation of patient sera with grass pollen. The peroxidase-1- and beta-glucosidase-specific IgE tests identified three and four of six patients with GPWA, respectively, but only two of 29 controls, indicating high specificity of these tests. CONCLUSIONS: Peroxidase-1 and beta-glucosidase are specific wheat allergens for GPWA among grass pollen allergy and other types of wheat-induced food allergies.

Interleukin-8 Release Inhibitors Generated by Fermentation of Artemisia princeps Pampanini Herb Extract With Lactobacillus plantarum SN13T.

Some glycosides, which are detected in water extracts from medicinal plants, have been reported to be degraded into their aglycones by incubating with some microorganisms producing ß-glucosidase. We have shown that a plant-derived Lactobacillus plantarum SN13T harbors 11 open reading frames (ORFs) encoding the ß-glucosidase enzyme and can grow vigorously in several herbal water extracts. In this study, we observed that the water extract from Artemisia princeps Pampanini (AP) fermented with the SN13T strain strongly inhibited the release of interleukin (IL)-8 from the HuH-7 cells, when compared to that without fermentation. Furthermore, we demonstrated that the SN13T strain produced at least two bioactive compounds from some compounds contained in AP extract. In addition, we determined that the two compounds were catechol and seco-tanapartholide C, which dose-dependently inhibited the release of IL-8. Because some sesquiterpene lactones are useful in pharmaceuticals, seco-tanapartholide C may be useful as an anti-inflammatory agent. This study suggests that the fermentation of medicinal herbs with Lb. plantarum SN13T is a significant technique to obtain bioactive compounds having therapeutic potential.

Exercise-induced allergic reactions on desensitization to wheat after rush oral immunotherapy.

BACKGROUND: The effect of oral immunotherapy (OIT) on wheat allergy is promising in terms of the potential to obtain desensitization; however, the frequency of exercise-induced allergic reactions on desensitization (EIARDs) and the associated risk factors remain to be determined. METHODS: Twenty-five patients underwent rush OIT for wheat allergy, and 21 achieved the full-dose intake of wheat products (5 g of wheat protein). Exercise-provocation tests were repeatedly performed after the ingestion of a full-dose wheat product. The time-course of the levels of the specific IgEs (sIgE) to wheat extract, total gliadin, deamidated gliadin, recombinant gliadin components (α/ß-, γ- and ω-5-), and glutenin (high and low molecular weight) components was analyzed using ImmunoCAP® , ELISA, or IgE immunoblotting. RESULTS: Fourteen patients (66.7%) were diagnosed as EIARD+, which remained 5 years after rush OIT in 11 patients (52.4%). There were no differences in the clinical backgrounds of the EIARD+ and EIARD- patients. However, EIARD+ patients showed significantly higher sIgE levels to all gliadin and glutenin components than EIARD- patients before OIT. The sIgE levels to each component decreased equally after 1 and 2 years of OIT. On IgE immunoblotting, sera from all patients reacted to the multiple gluten bands, and some reacted to the water-soluble bands. The intensity of all IgE-reactive bands also became equally lighter after OIT. CONCLUSIONS: EIARDs were frequently observed and remained for a long period after successful OIT for wheat allergy. None of the specific wheat components were found to contribute to EIARDs.

Aspirin enhances sensitization to the egg-white allergen ovalbumin in rats.

Enhancement of oral absorption of food allergens by non-steroidal anti-inflammatory drugs (NSAIDs), especially aspirin, is considered an exacerbating factor in the development of food allergies. In this study, we examined the effect of aspirin on oral sensitization to and absorption of the egg-white allergen ovalbumin (OVA) in rats. The absorption of OVA was evaluated by measuring the plasma concentration of OVA after oral administration by gavage. To evaluate oral sensitization to OVA, plasma levels of immunoglobulin (Ig) E and IgG1 antibodies (Abs) specific to OVA were determined by enzyme-linked immunosorbent assay after initiation of sensitization. High-dose aspirin (30 mg/kg) increased oral OVA absorption and plasma levels of OVA-specific IgE and IgG1 Abs compared with those observed in vehicle-treated rats. In contrast, low-dose aspirin (3 mg/kg) exerted no changes in either absorption or sensitization. Spermine, an absorption enhancer, increased the oral absorption of OVA to nearly the same extent as high-dose aspirin, whereas the plasma levels of OVA-specific IgE and IgG1 Abs exhibited no significant differences between spermine- and vehicle-treated rats. Among the NSAIDs, diclofenac and indomethacin increased sensitization to OVA, similar to high-dose aspirin, but meloxicam exerted no effects on Ab levels. In conclusion, we showed that high-dose aspirin enhanced oral sensitization to OVA. Our study suggests that enhanced oral sensitization to OVA cannot be ascribed to increased absorption of OVA from the intestinal tract. Although the mechanisms underlying this enhancement of sensitization are still controversial, our study suggests that modification of cytokine production due to impairment of the intestinal barrier function and inhibition of cyclooxygenase-1 activity by aspirin may be involved.

Evaluation of the allergenicity of ω5-gliadin-deficient Hokushin wheat (1BS-18) in a wheat allergy rat model.

We previously developed Hokushin wheat line as a hypoallergenic wheat lacking ω5-gliadin (1BS-18), a major allergen for wheat-dependent exercise-induced anaphylaxis. However, the allergenicity of 1BS-18 has not been understood completely. In this study, we evaluated the allergenicity of 1BS-18 such as anaphylactic elicitation ability and sensitization ability using rats sensitized with ω5-gliadin or glutens prepared from Hokushin (Hokushin gluten) or 1BS-18 (1BS-18 gluten). Rats were sensitized by intraperitoneal administration of ω5-gliadin, Hokushin gluten or 1BS-18 gluten. Immunoglobulin E-mediated systemic anaphylaxis was evaluated by measuring changes in rectal temperature for 30 min after intravenous challenge with ω5-gliadin or the test glutens in unsensitized rats or rats sensitized with ω5-gliadin or the test glutens. In ω5-gliadin-sensitized rats, intravenous challenge with ω5-gliadin or Hokushin gluten significantly decreased the rectal temperature at 30 min after challenge while challenge with 1BS-18 gluten did not reduce the rectal temperature. Furthermore, intravenous challenge with ω5-gliadin significantly decreased the rectal temperature in rats sensitized with Hokushin gluten or 1BS-18 gluten. However, the reduced degree observed in 1BS-18 gluten-sensitized rats was smaller than that in Hokushin gluten-sensitized rats. In conclusion, 1BS-18 elicited no allergic reaction in ω5-gliadin-sensitized rats and had less sensitization ability for ω5-gliadin than that of Hokushin wheat.

Blockade of multiple monoamines receptors reduce insulin secretion from pancreatic ß-cells.

Clinical use of olanzapine frequently causes severe hyperglycemia as an adverse effect. In this study, we elucidated mechanisms by which olanzapine reduced insulin secretion using the hamster pancreatic ß-cell line HIT-T15. Reverse transcriptional-PCR analysis revealed expression of dopamine (D2, D3 and D4), serotonin (5-HT2A, 5-HT2B, 5-HT2C, and 5-HT6), and histamine (H1 and H2) receptors in HIT-T15 cells. Olanzapine decreased insulin secretion from HIT-T15 cells at clinically relevant concentrations (64-160 nM). A dopamine D2 agonist, D3 antagonist, and D4 antagonist suppressed insulin secretion, whereas a D2 antagonist and D3 agonist increased it. A serotonin 5-HT2B agonist slightly increased insulin secretion, while a 5-HT2C antagonist slightly decreased it. Other agonists and antagonists for serotonin receptors did not affect insulin secretion. A histamine H1 agonist increased insulin secretion, whereas an H1 antagonist and H2 agonist suppressed it. Our results suggest that dopamine (D2, D3 and D4), serotonin (5-HT2B and 5-HT2C), and histamine (H1 and H2) receptors, which are expressed on pancreatic ß-cells, directly modulate insulin secretion from pancreatic ß-cells. Thus, olanzapine may induce hyperglycemia in clinical settings by suppressing insulin secretion from pancreatic ß-cells through inhibition of dopamine D3, serotonin 5-HT2B and 5-HT2C, and histamine H1 receptors.

Intestinal absorption of the wheat allergen gliadin in rats.

BACKGROUND: Aspirin enhances food allergy symptoms by increasing absorption of ingested allergens. The objective of this study is to elucidate the role of aspirin in facilitating intestinal absorption of the wheat allergen, gliadin, in rats. METHODS: Plasma concentrations of gliadin were determined after oral administration by gavage or administration into a closed intestinal loop in rats. We used an in situ intestinal re-circulating perfusion experiment to examine the effect of pepsin on aspirin-facilitated gliadin absorption. Fluorescein isothiocyanate (FITC)-labeled dextran-40 (FD-40) was used as a marker of non-specific absorption. The molecular size of gliadin and its allergenicity in plasma were examined using immunoblot analysis and intradermal reaction tests with Evans blue dye (EBD) extravasation, respectively. RESULTS: Aspirin increased plasma concentrations of gliadin after oral administration but had no effect in the closed intestinal loop study. An in situ intestinal re-circulating perfusion study showed that FITC-labeled gliadin was absorbed similarly to FD-40. Aspirin increased absorption of both intact and pepsin-digested gliadin, with a more significant effect on absorption of pepsin-treated gliadin. Immunoblotting showed that most gliadin was absorbed in intact form. When the gliadin fraction was extracted from rat plasma after gavage and injected intradermally into gliadin-sensitized rats, EBD extravasation was observed at injection sites in a gliadin dose-dependent manner. CONCLUSIONS: Aspirin increased the absorption of intact and pepsin-digested gliadin via the paracellular pathway, maintaining their allergenicity. Moreover, the effect of aspirin on gliadin absorption was enhanced by modification and digestion of gliadin in the stomach.

Evaluation of Risk of Injury by Extravasation of Hyperosmolar and Vasopressor Agents in a Rat Model.

Inadvertent leakage of noncytotoxic agents causes severe tissue injury. In this study, we macroscopically and histopathologically evaluated the extent of skin injury caused by extravasation of hyperosmolar or vasopressor agents in rats. Rats were intradermally administered saline (100 µL), the hyperosmolar agents mannitol (5-20 mg/100 µL) and glucose (5-50 mg/100 µL), or the vasopressors dopamine (2 mg/100 µL), adrenaline (0.1 mg/100 µL), and noradrenaline (0.1 mg/100 µL). Lesion size (erythema, induration, ulceration, and necrosis) was monitored after agent injection. Skin tissue biopsies were evaluated at 24 h after agent injection. Mannitol and glucose induced severe lesions in a concentration (and osmolarity)-dependent manner. Mannitol and glucose at 10-20% (w/v) induced inflammation, and lesions healed within 3-6 d. In contrast, ≥25% (w/v) glucose elicited severe skin lesions with ulceration and necrosis within 24 h, which healed gradually 16-22 d after injection. The severity of extravasation injury caused by vasopressors varied. Adrenaline and noradrenaline induced severe injury with ulceration and necrosis, which healed over 23.3 and 18.3 d, respectively. In contrast, dopamine induced erythema and induration, and damage duration was only 5.7 d. In conclusion, mannitol and glucose at osmolarities of 549-1098 and 833-1110 mOsm/L, respectively, can be classified as "irritants," while ≥1388 mOsm/L glucose can be classified as a "vesicant." As for vasopressors, adrenaline and noradrenaline can be classified as "vesicants" whereas dopamine can be classified as an "irritant."