Intranasal administration of ceramide liposome suppresses allergic rhinitis by targeting CD300f in murine models.

Allergic rhinitis (AR) is caused by type I hypersensitivity reaction in the nasal tissues. The interaction between CD300f and its ligand ceramide suppresses immunoglobulin E (IgE)-mediated mast cell activation. However, whether CD300f inhibits the development of allergic rhinitis (AR) remains elusive. We aimed to investigate the roles of CD300f in the development of AR and the effectiveness of intranasal administration of ceramide liposomes on AR in murine models. We used ragweed pollen-induced AR models in mice. Notably, CD300f deficiency did not significantly influence the ragweed-specific IgE production, but increased the frequency of mast cell-dependent sneezing as well as the numbers of degranulated mast cells and eosinophils in the nasal tissues in our models. Similar results were also obtained for MCPT5-exprssing mast cell-specific loss of CD300f. Importantly, intranasal administration of ceramide liposomes reduced the frequency of sneezing as well as the numbers of degranulated mast cells and eosinophils in the nasal tissues in AR models. Thus, CD300f-ceramide interaction, predominantly in mast cells, alleviates the symptoms and progression of AR. Therefore, intranasal administration of ceramide liposomes may be a promising therapeutic approach against AR by targeting CD300f.

A novel concept of passive loop-forming wire-guided biliary cannulation using an ultra-deep angled tip guidewire (with video).

Background and study aims Wire-guided biliary cannulation (WGBC) is a standard technique during endoscopic retrograde cholangiopancreatography-related interventions. However, no dedicated guidewire is available. We investigated a novel "passive loop-forming WGBC" concept using a 0.035-inch ultra-deep angled tip guidewire. Patients and methods This single-arm, single-center, retrospective study included consecutive 111 patients who underwent passive loop-forming WGBC as the first biliary intervention between October 2021 and December 2022. Results WGBCs were completed within 5 minutes and overall were performed at a median papillary negotiation time of 81 seconds (interquartile range [IQR], 39-170) and 114 seconds (IQR, 49-303) in 83 (74.8%) and 106 (95.5%) cases, respectively. Logistic regression analysis identified age ≥ 80 years (odds ratio [OR]: 3.56, 95% confidence interval [CI]: 1.12-11.31) and unintentional pancreatic guidewire insertion (OR: 17.67, 95% CI: 5.75-54.31) as significant risk factors for failed WGBC within 5 minutes. Among the 106 obtained cannulations, the guidewire leading part formed a small-looped tip and wide-looped body in 83 (78.3%) and 23 (21.7%) cases, respectively. Adverse events included post-procedure pancreatitis (2/111 [1.8%]) and guidewire penetration (3/111 [2.7%]). Conclusions Passive loop-forming WGBC using an ultra-deep angled tip guidewire is a feasible procedure.

Impact of a Time-Related Benchmark on the Adenoma Detection Rate in Surveillance Colonoscopy: A STROBE Statement-Oriented Cross-Sectional Cohort Study.

BACKGROUND/AIMS: Colorectal adenomas are precursor lesions of globally increasing colorectal cancer. Hence, a high adenoma detection rate in colonoscopy is pivotal. We investigated the clinical impact of stratified colonoscopy observation time combined with observation time/intubation time ratio on the detection of colorectal adenomas. MATERIALS AND METHODS: We conducted a single-center retrospective study including 369 consecutive patients who underwent colonoscopy following fecal immunochemical tests between May 2021 and April 2022. The primary outcome measure was the impact of the stratified observation time and observation time/ intubation time ratio (category 1: <6.0 minutes and <1.0, category 2: <6.0 minutes and ≥1.0, category 3: ≥6.0 minutes and <1.0, and category 4: ≥6.0 minutes and ≥1.0) on adenoma detection rate. RESULTS: Cecum intubation was obtained in 367 patients (99.5%). Adenomas were detected in 226 patients (61.2%). From the univariate analysis, age ≥53 years, habitual alcohol intake, colonoscopy attachment (+), and observation time with observation time/intubation time ratio categories 3 and 4 were determined as significant factors for adenoma detection rate. From the logistic regression analysis, age ≥ 53 years (odds ratio: 4.86, 95% CI: 2.25-10.52), habitual alcohol intake (odds ratio: 2.26, 95% CI: 1.33-3.82), category 3 (odds ratio: 3.66, 95% CI: 1.81-7.45), and category 4 (odds ratio: 5.60, 95% CI: 2.92-10.73) were significant factors for adenoma detection rate. CONCLUSION: We propose the observation time with observation time/intubation time ratio combined benchmark (with categories' thresholds based on observation time >6 minutes and scope withdrawal time exceeding intubation time [observation time/intubation time ratio > 1]) as a novel colonoscopy quality indicator. These findings represent an important educational message for endoscopists.

A nerve-goblet cell association promotes allergic conjunctivitis through rapid antigen passage.

The penetration of allergens through the epithelial layer is the initial step in the development of allergic conjunctivitis. Although pollinosis patients manifest symptoms within minutes after pollen exposure, the mechanisms of the rapid transport of the allergens remain unclear. In the present study, we found that the instillation of pollen shells rapidly induces a large number of goblet cell-associated antigen passages (GAPs) in the conjunctiva. Antigen acquisition by stromal cells, including macrophages and CD11b+ dendritic cells, correlated with surface GAP formation. Furthermore, a substantial amount of antigen was transported to the stroma during the first 10 minutes of pollen exposure, which was sufficient for the full induction of an allergic conjunctivitis mouse model. This inducible, rapid GAP formation and antigen acquisition were suppressed by topical lidocaine or trigeminal nerve ablation, indicating that the sensory nervous system plays an essential role. Interestingly, pollen shell-stimulated GAP formation was not suppressed by topical atropine, suggesting that the conjunctival GAPs and intestinal GAPs are differentially regulated. These results identify pollen shell-induced GAP as a therapeutic target for allergic conjunctivitis.

Murine model identifies tropomyosin as IgE cross-reactive protein between house dust mite and coho salmon that possibly contributes to the development of salmon allergy.

Background: Recently, we have developed a method to identify IgE cross-reactive allergens. However, the mechanism by which IgE cross-reactive allergens cause food allergy is not yet fully understood how. In this study, we aimed to understand the underlying pathogenesis by identifying food allergens that cross-react with house dust mite allergens in a murine model. Material and methods: Allergenic protein microarray analysis was conducted using serum from mice intraperitoneally injected with Dermatophagoides pteronyssinus (Der p) extract plus alum or alum alone as controls. Der p, Dermatophagoides farinae (Der f), coho salmon extract-sensitized and control mice were analyzed. Serum levels of IgE against Der p, Der f, coho salmon extract, protein fractions of coho salmon extract separated by ammonium sulfate precipitation and anion exchange chromatography, and recombinant coho salmon tropomyosin or actin were measured by an enzyme-linked immunosorbent assay. A murine model of cutaneous anaphylaxis or oral allergy syndrome (OAS) was established in Der p extract-sensitized mice stimulated with coho salmon extract, tropomyosin, or actin. Results: Protein microarray analysis showed that coho salmon-derived proteins were highly bound to serum IgE in Der p extract-sensitized mice. Serum IgE from Der p or Der f extract-sensitized mice was bound to coho salmon extract, whereas serum IgE from coho salmon extract-sensitized mice was bound to Der p or Der f extract. Analysis of the murine model showed that cutaneous anaphylaxis and oral allergic reaction were evident in Der p extract-sensitized mice stimulated by coho salmon extract. Serum IgE from Der p or Der f extract-sensitized mice was bound strongly to protein fractions separated by anion exchange chromatography of coho salmon proteins precipitated with 50% ammonium sulfate, which massively contained the approximately 38 kDa protein. We found that serum IgE from Der p extract-sensitized mice was bound to recombinant coho salmon tropomyosin. Der p extract-sensitized mice exhibited cutaneous anaphylaxis in response to coho salmon tropomyosin. Conclusion: Our results showed IgE cross-reactivity of tropomyosin between Dermatophagoides and coho salmon which illustrates salmon allergy following sensitization with the house dust mite Dermatophagoides. Our method for identifying IgE cross-reactive allergens will help understand the underlying mechanisms of food allergies.

Staphylococcus aureus δ-toxin present on skin promotes the development of food allergy in a murine model.

Background: Patients with food allergy often suffer from atopic dermatitis, in which Staphylococcus aureus colonization is frequently observed. Staphylococcus aureus δ-toxin activates mast cells and promotes T helper 2 type skin inflammation in the tape-stripped murine skin. However, the physiological effects of δ-toxin present on the steady-state skin remain unknown. We aimed to investigate whether δ-toxin present on the steady-state skin impacts the development of food allergy. Material and methods: The non-tape-stripped skins of wild-type, KitW-sh/W-sh, or ST2-deficient mice were treated with ovalbumin (OVA) with or without δ-toxin before intragastric administration of OVA. The frequency of diarrhea, numbers of jejunum or skin mast cells, and serum levels of OVA-specific IgE were measured. Conventional dendritic cell 2 (cDC2) in skin and lymph nodes (LN) were analyzed. The cytokine levels in the skin tissues or culture supernatants of δ-toxin-stimulated murine keratinocytes were measured. Anti-IL-1α antibody-pretreated mice were analyzed. Results: Stimulation with δ-toxin induced the release of IL-1α, but not IL-33, in murine keratinocytes. Epicutaneous treatment with OVA and δ-toxin induced the local production of IL-1α. This treatment induced the translocation of OVA-loaded cDC2 from skin to draining LN and OVA-specific IgE production, independently of mast cells and ST2. This resulted in OVA-administered food allergic responses. In these models, pretreatment with anti-IL-1α antibody inhibited the cDC2 activation and OVA-specific IgE production, thereby dampening food allergic responses. Conclusion: Even without tape stripping, δ-toxin present on skin enhances epicutaneous sensitization to food allergen in an IL-1α-dependent manner, thereby promoting the development of food allergy.

Regulation of Syk activity by antiviral adaptor MAVS in FcεRI signaling pathway.

Background: Mast cells are the major effector cell type for IgE-mediated allergic reactions. Recent studies revealed a role for mast cells in orchestrating the host response to viral infections. Objective: We studied the relationship between FcεRI (high-affinity IgE receptor) and RIG-I-like receptor (RLR)-mediated antiviral signaling pathways. Methods: Mast cells (BMMCs) were cultured from bone marrow cells from mice deficient in MAVS or other RLR signaling molecules. MAVS expression was restored by retroviral transduction of MAVS-deficient BMMCs. These cells were stimulated with IgE and antigen and their activation (degranulation and cytokine production/secretion) was quantified. FcεRI-mediated signaling events such as protein phosphorylation and Ca2+ flux were analyzed by western blotting and enzyme assays. WT and mutant mice as well as mast cell-deficient KitW-sh/W-sh mice engrafted with BMMCs were subjected to passive cutaneous anaphylaxis. Results: Unexpectedly, we found that mast cells devoid of the adaptor molecule MAVS exhibit dramatically increased cytokine production upon FcεRI stimulation, despite near-normal degranulation. Consistent with these observations, MAVS inhibited tyrosine phosphorylation, thus catalytic activity of Syk kinase, the key signaling molecule for FcεRI-mediated mast cell activation. By contrast, mast cells deficient in RIG-I, MDA5 or IRF3, which are antiviral receptor and signaling molecules upstream or downstream of MAVS, exhibited reduced or normal mast cell activation. MAVS-deficient mice showed enhanced late-phase responses in passive cutaneous anaphylaxis. Conclusion: This study demonstrates that the adaptor MAVS in the RLR innate immune pathway uniquely intersects with the adaptive immune FcεRI signaling pathway.

A Rare Case of New-Onset Crohn's Disease in a Patient With Chronic Palmoplantar Pustulosis.

A 44-year-old woman who had been diagnosed with palmoplantar pustulosis (PPP) at 34 years old was diagnosed with moderate Crohn's disease (CD) based on endoscopic, radiological, and pathological findings. As treatment with corticosteroids, ultraviolet, and cyclosporin had achieved partial response, PPP had been refractory in a chronic continuous state. Oral prednisolone was initially started to treat CD, but clinical remission was not achieved. Intravenous ustekinumab was subsequently started at 260 mg for clinical remission of CD. Eight weeks after starting ustekinumab, clinical remission and mucosal healing were achieved and PPP manifestations on the palms and soles were markedly improved. Ustekinumab appears to offer an effective therapeutic option for patients with PPP but has yet to be approved for this induction in Japan. CD is a rare gastrointestinal involvement in PPP patients that requires attention.

Induction Therapy With a Combination of Weekly Adalimumab Plus Intensive Granulocyte and Monocyte Adsorptive Apheresis in Patients With Ulcerative Colitis and Failure of Conventional Agents, Biologics and Janus Kinase Inhibitor.

Every-week (ew) adalimumab (ADA) maintenance following induction therapy with a standard induction regimen has recently been approved for use in Japan. The efficacy and safety of combination therapy with ew-ADA maintenance following standard induction regimen plus intensive granulocyte and monocyte adsorptive apheresis (GMA) (two sessions/week) for the treatment of refractory ulcerative colitis (UC) displaying failure of conventional, biologics and Janus kinase inhibitor have not been evaluated previously. The present retrospective study evaluated the 10-week efficacy of this combination therapy among refractory UC patients. Six patients were given initial ADA combination therapy (ADA at 160 mg in week 0, ADA 80 mg in week 2, and 40 mg in week 4, followed by ew-ADA at 40 mg/week) plus intensive GMA. One patient (16.6%) achieved clinical remission and two patients (33.3%) achieved endoscopic improvement by week 10. After excluding two patients who discontinued treatment, mean full Mayo score (P = 0.14), endoscopic subscore (P = 0.18) and C-reactive protein level (P = 0.27) at 10 weeks were numerically decreased compared with baseline in the remaining four cases, although the differences were not significant. Use of ew-ADA maintenance following standard induction regimen plus intensive GMA appears unlikely to achieve satisfactory induction of clinical remission in UC patients for whom conventional agents, biologics and Janus kinase inhibitors have failed.

Kaempferol Suppresses the Activation of Mast Cells by Modulating the Expression of FcεRI and SHIP1.

In the present study, we evaluated the effects of kaempferol on bone marrow-derived mast cells (BMMCs). Kaempferol treatment significantly and dose-dependently inhibited IgE-induced degranulation, and cytokine production of BMMCs under the condition that cell viability was maintained. Kaempferol downregulated the surface expression levels of FcεRI on BMMCs, but the mRNA levels of FcεRIα, ß, and γ-chains were not changed by kaempferol treatment. Furthermore, the kaempferol-mediated downregulation of surface FcεRI on BMMCs was still observed when protein synthesis or protein transporter was inhibited. We also found that kaempferol inhibited both LPS- and IL-33-induced IL-6 production from BMMCs, without affecting the expression levels of their receptors, TLR4 and ST2. Although kaempferol treatment increased the protein amount of NF-E2-related factor 2 (NRF2)-a master transcription factor of antioxidant stress-in BMMCs, the inhibition of NRF2 did not alter the suppressive effect of kaempferol on degranulation. Finally, we found that kaempferol treatment increased the levels of mRNA and protein of a phosphatase SHIP1 in BMMCs. The kaempferol-induced upregulation of SHIP1 was also observed in peritoneal MCs. The knockdown of SHIP1 by siRNA significantly enhanced IgE-induced degranulation of BMMCs. A Western blotting analysis showed that IgE-induced phosphorylation of PLCγ was suppressed in kaempferol-treated BMMCs. These results indicate that kaempferol inhibited the IgE-induced activation of BMMCs by downregulating FcεRI and upregulating SHIP1, and the SHIP1 increase is involved in the suppression of various signaling-mediated stimulations of BMMCs, such as those associated with TLR4 and ST2.

The protective role of conjunctival goblet cell mucin sialylation.

Gel-forming mucins secreted by conjunctival goblet cells have been implicated in the clearance of allergens, pathogens, and debris. However, their roles remain incompletely understood. Here we show that human and mouse conjunctival goblet cell mucins have Alcian blue-detectable sialic acids, but not sulfates in the steady state. Interestingly, Balb/c mouse strain lacks this sialylation due to a point mutation in a sialyltransferase gene, St6galnac1, which is responsible for sialyl-Tn synthesis. Introduction of intact St6galnac1 to Balb/c restores the sialylation of conjunctival goblet cell mucus. Sialylated mucus efficiently captures and encapsulates the allergen particles in an impenetrable layer, leading to the protection of mice from the development of allergic conjunctivitis. Expression of ST6GALNAC1 and sialyl-Tn is upregulated in humans under conditions with chronic stimuli. These results indicate that the sialylated glycans on the ocular mucins play an essential role in maintaining the conjunctival mucosa by protecting from the incoming foreign bodies such as allergen particles.

Potential Risk of Misjudgment in the Decision-making Process Based on the 2018 Tokyo Guidelines in Older Patients with Acute Cholecystitis.

Objective The 2018 Tokyo Guidelines (TG18) were published to facilitate the decision-making processes (DMP), including the diagnosis and operation of acute cholecystitis (AC). However, only a few guidelines consider older adults. This study evaluated the DMP based on the TG18, focusing on older patients with AC. Methods This was a single-armed, single-center retrospective study. The primary outcome measure was the "undiagnosable" AC rate, and the secondary outcome measure was the degree of concordance of "unfit for surgery" decisions. Patients Two hundred and nine patients with AC. Results Sixty (28.7%) of 209 patients with AC were "undiagnosable" on admission based on the TG18 criteria. The numbers and rate of "undiagnosable" AC in patients ≤59, 60-79, and ≥80 years old were 4 (10.0%), 20 (24.4%), and 36 (41.4%), respectively (p<0.001). The multiple logistic regression analysis following the univariate analysis revealed that age >73 years old was the most significant risk factor for undiagnosable AC [p=0.006, odds ratio (OR): 3.06, 95% confidence interval (CI): 1.38-6.81]. Female sex (p=0.033, OR: 2.09, 95% CI: 1.06-4.09) and severe AC (p=0.049, OR: 2.97, 95% CI: 1.01-8.76) were also significant risk factors for undiagnosable AC. The number of cases unfit for surgery based on the Charlson Comorbidity Index and American Society of Anesthesiologists physical status was 90 (43.1%) and 75 (35.9%), respectively. The κ value between these 2 indicators revealed a minimal concordance of 0.33 (95% CI: 0.20-0.47). Conclusion The DMP based on the TG18 potentially harbors a misjudgment risk, especially in older patients with AC (UMIN000047715).

A Transanal Endoscopic Ultrasound-guided Fine-needle Aspiration Biopsy for an Intrapelvic Tumor Diagnosed as Recurrence of a Smooth Muscle Tumor of Uncertain Malignant Potential Following Uterine Morcellation.

A transoral endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) is a well-established tissue-sampling method. However, performing a transanal EUS-FNAB remains challenging. Uterine morcellation has emerged as a minimally invasive approach for benign tumor treatment. However, uterine myomas are heterogeneous and include malignant and indeterminate malignant cells. We herein report a rare case of intrapelvic tumor diagnosed by a transanal EUS-FNAB as a recurrence of smooth muscle tumors of uncertain malignant potential following uterine morcellation. Physicians should be aware that a previous uterine myoma resected under morcellation has the possibility of intra-abdominal recurrence. A transanal EUS-FNAB is a practical option for making a pathological diagnosis.

Upadacitinib Plus Intensive Granulocyte and Monocyte Adsorptive Apheresis for Ulcerative Colitis Achieved Ulcer Healing for Pyoderma Gangrenosum.

A 44-year-old woman who had been diagnosed with ulcerative colitis (UC) at 22 years old was diagnosed with severe flare-up of UC based on endoscopic findings associated with new-onset active pyoderma gangrenosum (PG) on both lower legs after she decided to discontinue UC treatment. Systemic treatment with intravenous prednisolone at 30 mg/day had achieved insufficient response to UC and PG, resulting in a diagnosis of corticosteroid-refractory UC and PG. Combination therapy with upadacitinib at 45 mg/day plus intensive granulocyte and monocyte adsorptive apheresis (GMA) was started to achieve clinical remission of UC. Ten weeks after starting this combination therapy, clinical improvement of UC was achieved with PG ulcer healing on both lower legs. A combination of upadacitinib plus intensive GMA may offer an effective therapeutic option for patients with active PG in addition to UC but has yet to be approved for induction or maintenance treatment of PG worldwide. PG is a dermatological involvement in UC patients that requires attention.

Development of mouse model for oral allergy syndrome to identify IgE cross-reactive pollen and food allergens: ragweed pollen cross-reacts with fennel and black pepper.

Oral allergy syndrome (OAS) is an IgE-mediated immediate food allergy that is localized to the oral mucosa. Pollen food allergy syndrome (PFAS), a pollinosis-associated OAS, is caused by cross-reactivity between food and pollen allergens. However, we need to more precisely understand the underlying pathogenesis of OAS/PFAS. In the present study, we developed a method to comprehensively identify cross-reactive allergens by using murine model of OAS and protein microarray technology. We focused on lip angioedema, which is one of the most common symptoms of OAS, and confirmed that mast cells reside in the tissues inside the lower lip of the mice. Interestingly, when the food allergen ovalbumin (OVA) was injected inside the lower lip of mice with high levels of OVA-specific IgE followed by an intravenous injection of the Evans blue dye, we found immediate dye extravasation in the skin of the neck in a mast cell-dependent manner. In addition, the degree of mast cell degranulation in the oral cavity, reflecting the severity of oral allergic responses, can be estimated by measuring the amount of extravasated dye in the skin. Therefore, we used this model of OAS to examine IgE cross-reactive allergens in vivo. Protein microarray analysis showed that serum IgE from mice intraperitoneally sensitized with ragweed pollen, one of the major pollens causing pollinosis, bound highly to protein extracts from several edible plants including black peppercorn and fennel. We confirmed that the levels of black pepper-specific IgE and fennel-specific IgE were significantly higher in the serum from ragweed pollen-sensitized mice than in the serum from non-sensitized control mice. Importantly, analysis of murine model of OAS showed that the injection of black pepper or fennel extract induced apparent oral allergic responses in ragweed pollen-sensitized mice. These results indicate IgE cross-reactivity of ragweed pollen with black pepper and fennel. In conclusion, we developed mouse model of OAS to identify IgE cross-reactive pollen and food allergens, which will help understand the pathogenesis of OAS/PFAS.