Improved performance of the SH test as an in vitro skin sensitization test with a new predictive model and decision tree.

Demands for the elimination and replacement of animal experiments for cosmetic safety assessment have increased in recent years. Evaluation of skin sensitization, however, is a critical issue in cosmetic safety assessment. The SH test is an in vitro skin sensitization test method that evaluates protein binding of chemical substances, which is an important event in skin sensitization. We previously verified the technical transferability and between-laboratory reproducibility of the SH test, a domestic test method for which no scientific research has been conducted, and improved the protocol, but also noted some unresolved issues. Therefore, in the present study, we successfully improved the operational efficiency and clarity of the final judgment of the SH test by (i) developing a new decision-making system that can make a final judgment without statistical processing, (ii) changing the statistical method, and (iii) evaluating and determining the maximum number of repetitions necessary for optimal efficiency. The improved SH test was verified by comparing it with existing test methods already adopted by the Organization for Economic Cooperation and Development. The results of this study demonstrated excellent performance of the improved SH test, with high reproducibility, reliable predictability, and good operational efficiency. The predictive performance of the improved method does not differ significantly from that of the conventional method, although it is clearer and more efficient. Therefore, the results of the present improved method are consistent with those obtained using the conventional method, with higher efficiency.

Efficacy of elobixibat as bowel preparation agent for colonoscopy: Prospective, randomized, multi-center study.

BACKGROUND AND AIM: Elobixibat is a novel ileal bile acid transporter inhibitor. This study aimed to compare the efficacy, tolerability, and safety of the combination of elobixibat and 1 L of polyethylene glycol formulation containing ascorbic acid (PEG-Asc) solution versus the combination of sodium picosulfate and 1-L PEG-Asc solution as bowel preparation for colonoscopy. METHODS: This multi-center, randomized, observer-blinded, non-inferiority study recruited 210 outpatients who were assigned to either the elobixibat plus 1-L PEG-Asc group (group A) or the sodium picosulfate plus 1-L PEG-Asc group (group B). The quality of the bowel cleansing level was assessed by the Boston Bowel Preparation Scale (BBPS) and compared the bowel cleansing level between the groups. Data regarding bowel preparation time, patients' tolerability, and adverse events were also analyzed. RESULTS: Data for 196 patients (99 in group A and 97 in group B) were analyzed finally. BBPS was comparable between group A and B (8.3 ± 0.9 vs. 8.3 ± 0.7; P = 0.88). Consequently, the adequate bowel preparation rate in groups A and B was 95.0% and 99.0%, respectively (-4.0%, 95% CI -9.3 to 1.5). Bowel preparation time in group A was similar to that in group B (348.2 ± 79.8 min vs. 330.8 ± 82.5 min; P = 0.13), whereas, sleep disturbance was significantly less frequent in group A than in group B (10.2% vs. 22.7%; P = 0.02). CONCLUSIONS: The combination of elobixibat and 1-L PEG-Asc can be considered an alternative bowel preparation for colonoscopy considering the equivalent bowel cleansing effect and less frequent sleep disturbance. The Japan Registry of Clinical Trials (jRCTs41180026).

Gastrointestinal adverse reactions reduce the success rate of Helicobacter pylori eradication therapy: A multicenter prospective cohort study.

BACKGROUND: The screening and treatment of Helicobacter pylori infection for all junior high students in Saga Prefecture, Japan, were started in 2016. The present study aims to evaluate the influence of adverse reactions on the success of the eradication therapy. METHODS: From 2017 to 2019, 25,006 third-grade junior high school students were tested for urinary anti-H. pylori antibodies. Positive cases were confirmed by H. pylori stool antigen tests. Of the 531 students who were found to be H. pylori-positive, 390 (358 in first-line and 32 in second-line therapy) underwent eradication therapy, and 274 (242 in first-line and 32 in second-line) students actually completed a self-reported form to rate stool consistency (based on the Bristol Stool Scale), the maximum number of bowel movements, and abdominal symptoms during the 7 days of treatment. RESULTS: Among the 274 students, the total of primary and secondary eradication success rates was 87% (95% confidential interval: 82.9-90.1) in intention-to-treat analysis. On days 4, 5, and 6, stool consistency was looser in the primary eradication failure group than in the success group (p < .05). Looser stool consistencies were observed in male students with abdominal pain compared to those who did not experience pain (p < .05). Abdominal pain and diarrhea were detected in 28.5% and 42.7% of the subjects, respectively. The overall incidence of other adverse events was low (n = 8/274, 2.9%), and only two students discontinued treatment because of adverse events. CONCLUSIONS: Softening of the stool was related to the eradication failure in the junior high school students, especially in males with abdominal pain. Adverse effects did not induce discontinuation of the eradication treatment.

Propofol Sedation in the Endoscopy Room versus Operation Room during Endoscopic Submucosal Dissection for Gastric Tumors: A Propensity Score-Matching Analysis.

BACKGROUND/AIMS: The present study was performed to compare the safety of sedation with propofol during endoscopic submucosal dissection (ESD) for gastric tumors under sedation in the endoscopy room by an endoscopist versus sedation in the operation room by an anesthesiologist. METHODS: In total, 638 patients with gastric tumors who underwent ESD from January 2011 to August 2017 at Ureshino Medical Center and Saga Medical Center Koseikan were retrospectively reviewed. The patients were divided into 2 groups: those who underwent ESD in the endoscopy room (Group E, n = 532) and those who underwent ESD in the operation room (Group O, n = 106). Propensity score matching was applied for evaluation. The treatment outcome of ESD and the adverse events of sedation during ESD (desaturation, hypotension, bradycardia, and arrhythmia) were compared between the 2 groups to consider the safety of ESD. RESULTS: The propensity score-matching analysis created 82 matched pairs. Adjusted comparisons between Groups E and O showed similar treatment outcomes of ESD for gastric tumors. There were no significant differences in the treatment outcomes, anesthesia time, and mean propofol dose between the 2 groups. With respect to adverse events, desaturation occurred more often in Group E than Group O (18.3 vs. 3.7%, respectively; p = 0.005). There were no significant differences in other adverse events (hypotension, bradycardia, and arrhythmia) between the 2 groups. CONCLUSION: Sedation with propofol in the operation room might be required to ensure safer application of ESD for gastric tumors. However, a decrease in the desaturation rate was the only disadvantage of sedation in the endoscopy room.

Risk Factors for Delayed Hemorrhage after Colonic Endoscopic Mucosal Resection in Patients Not on Antithrombotic Therapy: Retrospective Analysis of 3,844 Polyps of 1,660 Patients.

BACKGROUND/AIMS: Colonic endoscopic mucosal resection (EMR) is safe for patients without antithrombotic therapy; however, EMR is associated with several risks. This study was performed to evaluate the risk of delayed hemorrhage in patients undergoing EMR without antithrombotic therapy. METHODS: In the present retrospective single-center study, 1,792 patients without antithrombotic therapy underwent colonic EMR from March 2012 to December 2016 at the Saga Medical Centre Koseikan. Risk factors were evaluated with respect to patient and lesion characteristics, the endoscopist's experience, and preventive hemoclips. Delayed hemorrhage was defined as bleeding for which emergency endoscopic hemostasis was applied >24 h after EMR. RESULTS: Among the 1,792 patients, 1,660 with 3,844 tumors were evaluated. Delayed hemorrhage occurred in 43 patients (2.6%) and 46 polyps (1.2%). Preventive hemoclips were applied in 996 patients (60.0%). Univariate analysis indicated that delayed hemorrhage occurred more frequently in young patients (3-39 years, p < 0.001, 40-59 years, p = 0.005) compared to > 60 years and in association with large polyps (> 10 mm, p = 0.003), hemoclip (p = 0.019), and pedunculated polyps (p = 0.024). Multivariate analysis indicated that risk factors for hemorrhage were young age (age of 3-39 years p < 0.001, 40-59 years, p = 0.005) and large polyps (> 10 mm, p < 0.001). The risk of delayed hemorrhage was increased by an estimated 8% with a 1-mm increase in polyp size. CONCLUSION: The present study suggests that young age (under 60 years old) and large polyp size are risk factors for causing delayed hemorrhage after colonic EMR in patients without antithrombotic therapy.

Efficacy and safety of Helicobacter pylori eradication therapy immediately after endoscopic submucosal dissection.

BACKGROUND AND AIMS: In the treatment of patients after endoscopic submucosal dissection (ESD), there is no consensus on the optimum time to start Helicobacter pylori eradication therapy or on whether eradication therapy improves ulcer healing rate after ESD. The aim of this study was to examine the effect of immediate eradication of H. pylori on ulcer healing after ESD in patients with early gastric neoplasms. METHODS: A total of 330 patients who underwent ESD for early gastric neoplasms were enrolled. Patients were assigned to either H. pylori eradication group (Group A: H. pylori eradication + proton pump inhibitor 7 weeks) or non-eradication group (Group B: proton pump inhibitor 8 weeks). The primary end point was gastric ulcer healing rate (Group A vs Group B) determined on week 8 after ESD. RESULTS: Patients in Group A failed to meet non-inferiority criteria for ulcer scarring rate after ESD compared with that in Group B (83.0% vs 86.5%, P for non-inferiority = 0.0599, 95% confidence interval: -11.7% to 4.7%). There were, however, neither large differences between the two groups in the ulcer scarring rate nor the safety profile. CONCLUSIONS: This study failed to demonstrate the non-inferiority of immediate H. pylori eradication therapy after ESD to the non-eradication therapy in the healing rate of ESD-caused ulcers. However, because the failure is likely to attribute to small number of patients enrolled, immediate eradication therapy may be a treatment option for patients after ESD without adverse effects on eradication therapy in comparison with the standard therapy.

[Recalcitrant pouchitis treated by budesonide foam:a case report].

This report presents the case of a 54-year-old man who had undergone restorative proctocolectomy with ileal pouch-anal anastomosis 15 years previously because of acute severe ulcerative colitis. After the operation, he experienced recalcitrant pouchitis and recurrent ulcer bleeding. There was a marked improvement in his symptoms following the administration of twice-daily budesonide 2mg foam injection for two months. Budesonide foam is suggested as a new therapy for pouchitis.

ß-NMR measurements of molecular-scale lithium-ion dynamics in poly(ethylene oxide)-lithium-salt thin films.

ß-detected NMR (ß-NMR) has been used to study the molecular-scale dynamics of lithium ions in thin films of poly(ethylene oxide) (PEO) containing either lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) or lithium trifluoroacetate (LiTFA) salts at monomer-to-salt ratios (EO/Li) of 8.3. The results are compared with previous ß-NMR measurements on pure PEO and PEO with lithium triflate (LiOTf) at the same loading [McKenzie et al., J. Am. Chem. Soc. 136, 7833 (2014)]. Activated hopping of 8Li+ was observed in all of the films above ∼250 K, with the hopping parameters strongly correlated with the ionicity of the lithium salt rather than the polymer glass transition temperature. The pre-exponential factor increases exponentially with ionicity, while the activation energy for hopping increases approximately linearly, going from 6.3±0.2 kJ mol-1 in PEO:LiTFA to 17.8±0.2 kJ mol-1 in PEO:LiTFSI. The more rapid increase in the pre-exponential factor outweighs the effect of the larger activation energy and results in 8Li+ hopping being fastest in PEO followed by PEO:LiTFSI, PEO:LiOTf, and PEO:LiTFA.

ß-NMR measurements of lithium ion transport in thin films of pure and lithium-salt-doped poly(ethylene oxide).

ß-Detected nuclear spin relaxation of (8)Li(+) has been used to study the microscopic diffusion of lithium ions in thin films of poly(ethylene oxide) (PEO), where the implanted lithium ions are present in extremely low concentration, and PEO with 30 wt % LiCF3SO3 over a wide range of temperatures both above and below the glass transition temperature. Recent measurements by Do et al. [Phys. Rev. Lett. 2013, 111, 018301] found that the temperature dependence of the Li(+) conductivity was identical to that of the dielectric α relaxation and was well described by the Vogel-Fulcher-Tammann relation, implying the α relaxation dominates the Li(+) transport process. In contrast, we find the hopping of Li(+) in both samples in the high temperature viscoelastic phase follows an Arrhenius law and depends significantly on the salt content. We propose that the hopping of Li(+) between cages involves motion of the polymer but that it is only for long-range diffusion where the α relaxation plays an important role.

Efficacy and safety of vonoprazan-based regimen for Helicobacter pylori eradication therapy in Japanese adolescents: a prospective multicenter study.

BACKGROUND: Vonoprazan (VPZ)-based regimen for Helicobacter pylori (H. pylori) is safe and more efficacious than the proton pump inhibitor-based regimen mainly in adults. This study aimed to evaluate the efficacy and safety of a VPZ-based regimen for H. pylori eradication therapy in adolescents. METHODS: An H. pylori screening and treatment longitudinal project for third-year junior high school students in Saga Prefecture began in 2016. Students who tested positive for both urine and stool tests received a VPZ-based regimen. On the checklist, students were asked for diarrhea, fever, abdominal pain, nausea, vomiting, urticaria, dysgeusia, or bloody stool occurrence during the therapy. RESULTS: The longitudinal project for H. pylori screening and treatment among third-grade students in Saga Prefecture targeted 41,115 students from 2017 to 2021 and 836 as positive. Of the 645 students, 542 (84.0% in per protocol [PP] analysis and 73.6% in intention-to-treat [ITT] analysis) were successful in primary eradication therapy. The secondary eradication therapy was successful in 79 (96.3% in PP analysis and 76.7% in ITT analysis) of 82 students. In the primary eradication therapy, abdominal pain occurred in 164 (27.9%), diarrhea in 217 (36.9%), nausea or vomiting in 7 (1.2%), and urticaria in 13 (2.2%) students. In the secondary eradication therapy, abdominal pain occurred in 12 (19.4%) and diarrhea in 17 (27.4%) students. The eradication therapy of 5 students was interrupted due to adverse events only by primary eradication therapy. CONCLUSIONS: VPZ-based regimen for H. pylori was efficacious and safe for adolescents, as in adults, for both primary and secondary eradication therapies.

Perforation and postoperative bleeding of endoscopic submucosal dissection in gastric tumors: analysis of 1190 lesions in low- and high-volume centers in Saga, Japan.

BACKGROUND: This retrospective study aimed to determine risk factors associated with serious complications of endoscopic submucosal dissection of gastric tumors in multicenters compared between high- and low-volume centers. METHODS: Between 2001 and 2010, gastric endoscopic submucosal dissection was performed in 1190 lesions of 1082 patients in five hospitals in Saga, three high-volume and two low-volume centers. Risk factors for serious complications were evaluated. Patients' background characteristics were evaluated, including anticoagulants use and underlying diseases. RESULTS: Postoperative bleeding was detected in 75 patients (6.9%), and perforation was detected in 40 patients (3.7%). Most postoperative bleeding and perforation cases were recovered with endoscopic procedures, although one case of each complication was treated by emergency surgery. Multivariate analysis indicated that risk factors for perforation were tumor location, massive submucusal invasion, endoscopists' experience of 100-149 cases and hypertension, and that risk factors for postoperative bleeding were tumor location, resected tumor size, and scar lesion. The serious complications were not different between high- and low-volume centers. CONCLUSIONS: The present study indicated that risk factors for perforation during endoscopic submucosal dissection were tumor, endoscopist and patient related, although risk factors for postoperative bleeding were tumor related. There was no difference in complications between high- and low-volume centers.

NSAIDs are a significant risk factor for colonic diverticular hemorrhage in elder patients: evaluation by a case-control study.

BACKGROUND AND AIM: Diverticular bleeding is a common cause of lower gastrointestinal hemorrhage. Several factors, including use of non-steroidal anti-inflammatory drugs (NSAIDs), antithrombotic agents and arteriosclerosis, could be risk factors. The aim of this study is to identify these risk factors. METHODS: Between January 2000 and December 2008, 51 patients among 178 acute lower gastrointestinal hemorrhages who visited Saga Medical School were diagnosed as colonic diverticular hemorrhage, established by emergency endoscopy and diagnostic criteria. Gender and age matched control cases were selected from patients of other diseases hospitalized during the same period. We evaluated by using logistic regression analysis the influences of comorbidities such as cerebrovascular disease, ischemic heart disease, hypertension, hyperlipidemia, diabetes mellitus, chronic kidney disease, and osteoporosis, medications including NSAIDs and antithrombotic agents, and habits of smoking, alcohol, and chronic constipation. RESULTS: Fifty one patients out of 178 acute lower gastrointestinal bleeding (28.7%) were diagnosed as diverticular hemorrhage, which was the most common cause of lower gastrointestinal hemorrhage. Sex ratio of men versus women for colonic diverticular hemorrhage was 35:16. NSAIDs were a significant risk factor for colonic diverticular hemorrhage in elder patients (odds ratio [OR] = 7.492, 95% CI: 1.516-37.024, P = 0.0135). Hypertension and hyperlipidemia had significant association with diverticular hemorrhage among patients younger than 65 years old. This study also indicated that use of NSAIDs was a risk factor for re-bleeding (OR = 5.4, 95% CI: 1.01-28.78, P = 0.048). CONCLUSION: This case-control study revealed that the use of NSAIDs was a significant risk factor for colonic diverticular hemorrhage in elder patients. In addition, use of NSAIDs is a risk factor for re-bleeding from colonic diverticula.

Enhancing between-facility reproducibility of the SH test as an in vitro skin sensitization test by the improved test method.

There has been an increased demand to eliminate animal experiments and to replace the experiments with alternative tests for assessing the safety of cosmetics. The SH test is an in vitro skin sensitization test that evaluates the protein binding abilities of a test substance. Skin sensitization must be evaluated by multiple test methods. The SH test uses the same cell line and measuring instruments as the human Cell-Line Activation Test (h-CLAT), which is one of the test methods used to evaluate different key events and is listed in the OECD test guidelines. There are cost advantages to usher the SH test into facilities that are already running the h-CLAT. The SH test is conducted only at a facility that has developed the SH test because studies on the between-facility reproducibility and validity have not been performed. Therefore, to verify the transferability of the SH test and the between-facilities reproducibility, we evaluated the reproducibility of the SH test results at three facilities, including the development facility. After an initial round of testing, the protocol was refined as follows to improve reproducibility among the three facilities: i) determine the optimum pH range, ii) change the maximum applicable concentration of water-soluble substances, and iii) define the appropriate dispersion conditions for evaluating hydrophobic substances. These refinements markedly enhanced the between-facility reproducibility (from 76.0% to 96.0%) for the 25 substances evaluated in this study. This study confirmed that the SH test is an effective skin sensitization test method with high technical transferability and between-facility reproducibility.

Safety and Efficacy of the Noncessation Method of Antithrombotic Agents after Emergency Endoscopic Hemostasis in Patients with Nonvariceal Upper Gastrointestinal Bleeding: A Multicenter Pilot Study.

Background and Aims: The present study aimed to clarify the safety and efficacy of the noncessation method of antithrombotic agents after emergency endoscopic hemostasis in patients with nonvariceal upper gastrointestinal bleeding (UGIB). Methods: In this multicenter, prospective, pilot study, we performed emergency endoscopic hemostasis for nonvariceal UGIB in patients taking antithrombotic agents and resumed the medications without a cessation period (group A). The clinical characteristics, types of antithrombotic agents, UGIB etiology, treatment outcome, and adverse events were evaluated. We used propensity score matching to compare treatment outcomes and adverse events with our previous cohort (group B) in whom antithrombotic agents were transiently discontinued after emergency endoscopic hemostasis. Results: Forty-three consecutive patients were prospectively enrolled. The main antithrombotic agents were low-dose aspirin and direct oral anticoagulants; 11 patients (25.6%) were taking multiple antithrombotics. Peptic ulcers were the main cause of bleeding (95.4%). Endoscopic hemostasis was successful in all patients and the incidence of rebleeding within a month was 7.0%. Propensity score matching created 40 matched pairs. Endoscopic hemostasis was performed by soft coagulation significantly more frequently in group A than in group B (97.5% versus 60.0%, P < 0.001). Neither the rebleeding rate within a month nor thromboembolic event rate was different between the two groups. However, the mean duration of hospitalization was significantly shorter in group A than in group B (8.6 ± 5.2 d versus 14.4 ± 7.1 d, P < 0.001). Conclusions: Antithrombotic agents possibly can be continued after successful emergency endoscopic hemostasis for nonvariceal UGIB.

Sensing of protein adsorption with a porous bulk composite comprising silver nanoparticles deposited on hydroxyapatite.

Porous bulk composites were produced by depositing silver nanoparticles of diameter 11.0 +/- 3.2 nm on hydroxyapatite of micrometer sizes. Adsorption of bovine serum albumin (BSA) and lysozyme (LSZ) on the composite material was observed in 2 and 10 mol m(-3) phosphate buffer solutions. More BSA than LSZ was adsorbed in 2 mol m(-3) phosphate buffer and this was attributed to a larger a-face surface area present in the plate- and rod-shaped hydroxyapatite compared with the c-face surface area. Peak shifts in localized surface plasmon resonance (LSPR) spectra were clearly related to adsorbed amounts of BSA and LSZ after exposure of the porous bulk composites to protein solutions. The sensing capability of the porous bulk composite results from changes in the dielectric constant of the surface fluid surrounding the silver nanoparticles. Adsorption/desorption cycles of BSA were applied to the porous bulk composite, confirming the reversibility of the sensing capability.

Rare complication of endoscopic band ligation for colonic diverticular bleeding.

A 79-year-old female patient receiving maintenance hemodialysis was referred to our hospital because of massive hematochezia. Abdominal enhanced computed tomography (CT) demonstrated extravasation of contrast medium in the descending colon. We then performed urgent colonoscopy, and successful endoscopic hemostasis was achieved using endoscopic band ligation (EBL) for a bleeding colonic diverticulum. However, the patient unexpectedly complained of severe abdominal pain and fever 5 days after EBL, and abdominal CT revealed free air and mesenteric panniculitis. Emergency surgery was performed, and delayed colonic perforation at the EBL site was confirmed. Although rare, delayed perforation after EBL for colonic diverticular bleeding should be considered.

The treatment for refractory rectovaginal fistula after low anterior resection with estriol, polyglycolic acid sheets and primary closure: A case report.

INTRODUCTION: Rectovaginal fistula (RVF) is a refractory complication that occurs after anastomotic leakage following low anterior resection for rectal disease. Due to its refractory nature, RVF is often managed with surgical treatment, such as stoma creation for fecal diversion, closure of the fistula and/or re-anastomosis, rather than conservative therapy. PRESENTATION OF CASE: A 72-year-old woman who underwent laparoscopic low anterior resection developed RVF on post-operative day (POD) 15. Conservative therapy with the administration of estriol and total parenteral nutrition was started. In addition, a polyglycolic acid (PGA) sheet was inserted into the fistula using colonoscopy, and fibrin glue was applied. However, this treatment with the PGA sheet and fibrin glue seemed to be unsuccessful. Therefore, an operation for simple closure of the RVF was performed on POD47. The PGA sheet was then removed, and primary closure of the RVF from both sides of the rectum and vagina was performed. Following re-operation, solid food with low dietary fiber content was started on original POD55 (POD14 after re-operation), and the dietary fiber content was gradually increased. The patient was discharged from the hospital on original POD 83 (re-operation POD42). DISCUSSION: The administration of estrogen might result in increased vaginal compliance, decreased vaginal pH, increased vaginal blood flow and improved lubrication. Therefore, vaginal suture was made possible because the vaginal extensibility was restored. CONCLUSION: Primary closure of the RVF following administration of estriol may be an effective treatment.

Endoscopic hemostasis with metallic hemoclips for iatrogenic Mallory-Weiss tear caused by endoscopic examination.

AIM: Applied endoscopic techniques including mucosal resection, sclerotherapy and endoscopic retrograde cholangiopancreatography (ERCP) have been advanced and iatrogenic complications including Mallory-Weiss tear (MWT) occasionally occur in daily endoscopic procedures. The present study aimed to examine the advantages of clipping for MWT complications that occur during endoscopic examination. METHODS: Over 10 years, we experienced 47 patients with bleeding caused by MWT. Metallic hemoclips were applied for 38 patients for hemostasis. These patients were categorized into two groups: 18 patients in group A whose bleeding tear occurred during endoscopic examination in an iatrogenic condition, and 20 patients in group B visited the emergency unit due to other etiology of MWT. RESULTS: The background characteristics, including length of tears, were not different between the two groups. Initial hemostasis was 100% in groups A and B. Rebleeding was 0/18 (0%) in group A and 1/20 (5 %) in group B. Number of patients who received blood transfusion was significantly higher in group B (group A: 0/18, group B: 4/20). Hemoglobin level before hemostasis was 12.5 g/dL in group A which was not different to that in group B, 10.9 g/dL. CONCLUSION: Application of hemoclips was effective for bleeding MWT during endoscopic procedures, which warranted prophylactic application of hemoclips on MWT during endoscopic examination.

Predicting the results of a 24-hr human patch test for surfactants: utility of margin-setting in a reconstructed human epidermis model.

To predict the results of a 24-hr closed human patch test, we previously recommended the use of in vitro test with a reconstructed human epidermis (RhE) model adopted in OECD TG 439, and proposed the margin method, which includes evaluation of twice the concentration to avoid a false positive for surfactants. Therefore, in this study, we used LabCyte EPI-MODEL as a RhE model, and confirmed the reproducibility of this method using five surfactants, including benzalkonium chloride (BC), sodium lauryl sulfate (SLS), and lauryl betaine (LB), for which false negative results have previously been reported, and three different surfactants. For all surfactants, prediction of patch test results using a margin of two revealed that human tests could be performed safely, confirming the utility of the margin method. In addition, we examined the relationship with critical micellar concentration (CMC). The IC50 for cell viability in the RhE model for three types of surfactants (BC, SLS, and LB) was 2.7- to 49.7-times the CMC. Therefore, the range of concentrations in which tests were performed with the present method was within the range of concentrations with high cleansing. Furthermore, we examined the relationship between cell viability and release of the inflammatory mediator interleukin-1α (IL-1α). IL-1α release was associated with cell viability, supporting the results of the human patch test.

Some non-sensitizers upregulate CD54 expression by activation of the NLRP3 inflammasome in THP-1 cells.

The human cell line activation test (h-CLAT) is a skin sensitization test that measures the expression of cell surface proteins CD86 and CD54 to evaluate the skin sensitization potential of test chemicals. However, some skin irritants have been reported to induce dramatically high CD54 expression leading to false-positive h-CLAT results. Furthermore, CD54 expression is strongly induced by cytokines, such as interleukin (IL)-1ß and tumor necrosis factor (TNF)-α, or danger signals that activate its signaling pathways. In this study, we focused on the relationship between CD54 expression and the Nucleotide binding domain, leucine-rich-containing family, pyrin domain containing 3 (NLRP3) inflammasome, a protein complex that plays a pivotal role in intra-cellular inflammation. We observed the activation of caspase-1 and production of IL-1ß after exposure of THP-1 cells to 2,4-dinitrochlorobenzene (DNCB, sensitizer), octanoic acid (OA, non-sensitizer), and salicylic acid (SA, non-sensitizer), implying NLRP3 activation. These observations confirmed the activation of the inflammasome by CD54-only positive chemicals. CD54 expression, induced by OA and SA, was suppressed by potassium chloride, a typical inhibitor of NLRP3 inflammasome activation. These results suggested that the NLRP3 inflammasome may be activated in THP-1 cells resulting in the expression of CD54, and subsequently leading to false-positive results.