The CXCL10-CXCR3 axis plays an important role in Kawasaki disease.

The precise pathogenesis of Kawasaki disease remains unknown. In an attempt to elucidate the pathogenesis of KD through the analysis of acquired immunity, we comprehensively examined the immunophenotypic changes in immune cells such as lymphocytes and monocytes along with various cytokines, focusing on differences between pre- and post- treatment samples. We found high levels of CXCL9 and CXCL10 chemokines that decreased with treatment, which coincided with a post-treatment expansion of Th1 cells expressing CXCR3. Our results show that the CXCL10-CXCR3 axis plays an important role in the pathogenesis of KD.

Time course of peripheral immunophenotypes of multisystem inflammatory syndrome in children.

The etiology of multiple inflammatory syndrome in children (MIS-C) remains poorly understood. As clues to elucidate the pathogenic condition, several characteristic peripheral immunophenotypes have been reported in MIS-C. However, no report has demonstrated the time course of the peripheral immunophenotype along with the clinical course in the same patient. Herein, we clarified the immunological characteristics of a Japanese patient with MIS-C. There was an initial cytokine storm followed by T-cell activation, especially of CD8+ T cells, with the expansion of T-cell receptor Vß 21.3-expressing cells, which suggests superantigen-mediated T-cell activation. In addition, we also found an increase in IgG-producing cells (plasmablasts and switched memory B cells), which were accompanied by elevated serum levels of anti-SARS-CoV-2 spike antigen-specific IgG antibodies. These time course of peripheral immunophenotypes support that immunological activation against SARS-CoV-2 spike protein plays a central role in the etiology of MIS-C.

Immunological characteristics of severe acute hepatitis of unknown origin in a child post SARS-CoV-2 infection.

Recent studies have reported that pediatric acute liver failure of unknown origin is immune-mediated, with CD8+ T cells playing a key role. Moreover, investigation of superantigen-mediated T-cell activation by the SARS-CoV-2 spike protein in pediatric severe acute hepatitis is needed in the context of the proposed mechanism of multisystem inflammatory syndrome in children (MIS-C). We investigated the immunological characteristics of a Japanese pediatric patient with severe acute hepatitis post SARS-CoV-2 infection. The patient demonstrated autoimmune hepatitis-like liver histology with CD8+ lymphocyte-predominant infiltration. There was Th1-type immune skewing, including remarkable peripheral CD8+ T-cell activation and a skewed T cell receptor repertoire. We also found elevated plasma levels of the anti-SARS-CoV-2 spike-specific IgG antibody, and the titer peaked after treatment, as seen with MIS-C. These findings support that immunological activation involving SARS-CoV-2 spike protein plays a crucial role in a pediatric patient with acute severe hepatitis post SARS-CoV-2 infection.

Managing bleeding risk after cold snare polypectomy in patients receiving direct-acting oral anticoagulants.

BACKGROUND AND AIMS: The best strategy to manage direct-acting oral anticoagulants (DOACs) for patients undergoing cold snare polypectomy remains unclear. This study compared the effect of continuing versus stopping DOACs only on the day of the procedure on bleeding after cold snare polypectomy. METHODS: This prospective, observational, single-center cohort study enrolled consecutive patients receiving antithrombotic agents and undergoing cold snare polypectomy of colorectal polyps ≤10 mm in diameter. During period 1 (2017 and 2018) antithrombotic agents including DOACs were not discontinued (DOAC continued group). In period 2 (2019 and 2020) DOACs were withheld only on the day of the procedure (DOAC withheld group) and restarted the next day after the procedure. The primary outcome was delayed bleeding requiring endoscopic treatment occurring within 2 weeks after cold snare polypectomy. Secondary outcomes were immediate bleeding and the number of hemostatic clips used. RESULTS: For the 2 groups, 204 (DOAC continued group; 34% women; mean age, 75 years) and 264 (DOAC withheld group; 36% women; mean age, 74 years) patients were enrolled. Clinical features were similar between the 2 groups. Delayed bleeding after cold snare polypectomy occurred in 4 of 47 patients (8.5%) in the DOAC continued group versus 0 of 66 (0%) in the DOAC withheld group (P < .001). Immediate postpolypectomy bleeding occurred in 12 of 47 patients (25.5%) in the DOAC continued group versus 4 of 66 (6.1%) in the DOAC withheld group (P < .008). CONCLUSIONS: Cold snare polypectomy may be safely preformed if DOACs are withheld only on the day of the procedure. (Clinical trial registration number: NCT02594813.).

Effectiveness of Water Jelly Ingestion for Both Rehabilitation and Prevention of Aspiration Pneumonia in Elderly Patients With Moderate to Severe Dysphagia.

BACKGROUND AND AIMS: We evaluated the effectiveness of water jelly ingestion for both rehabilitation and the prevention of aspiration pneumonia in a retrospective analysis of elderly patients with moderate to severe dysphagia. PATIENTS AND METHODS: Study 1: consecutive patients with borderline ingestion in an endoscopic swallowing evaluation were enrolled (n=36, 18 men and 18 women: mean age 82±9 y) and categorized into a group with water jelly (50 to 100 mL) ingestion training 3×/day or an untrained control group. Their food intake levels were then compared using a Food Intake Level Scale. Study 2: consecutive patients who were hospitalized because of aspiration pneumonia were enrolled (n=64, 35 men and 29 women: mean age 81±9 y) and categorized into a group with cyclic ingestion of water jelly immediately after each meal or a control group. The incidence of aspiration pneumonia that was newly developed during hospitalization was compared between the groups. RESULTS: In study 1, 36 patients with a Hyodo-Komagane score of 8 were enrolled. Three of the 12 (25%) patients who underwent water jelly ingestion training were able to eat a pureed diet (level 5, 2 patients; level 6, 1 patient) while none of the 24 patients (0%) who did not undergo this training were able to eat any form of diet (levels 5 and 6, no patients) (P=0.011). In study 2, 64 patients were enrolled. No newly developed aspiration pneumonia was observed in the 34 patients (0%) who received cyclic water jelly ingestion, whereas 17% (5/30) of patients not receiving water jelly after meals newly developed aspiration pneumonia during hospitalization (P=0.031). CONCLUSIONS: Water jelly ingestion was effective for both rehabilitation and the prevention of aspiration pneumonia in elderly patients with moderate to severe dysphagia.

Short-term intensive gastrointestinal endoscopy training program.

BACKGROUND: In Japan there are limited opportunities for pediatric gastrointestinal (GI) trainees to learn GI endoscopy. This study investigated whether a short-term intensive training for 3 months in an adult GI unit enabled pediatric GI trainees to acquire the required number of cases and the technical competence to perform pediatric GI endoscopic procedures. METHODS: This was a retrospective case series of pediatric GI trainees who underwent 3 months of intensive endoscopy training, which also included direct observation and a questionnaire. The numbers of esophagogastroduodenoscopies (EGD), ileocolonoscopies, and snare polypectomies each trainee performed as well as cecal intubation rates were collected with the goal of meeting the standards of overseas educational guidelines. The trainees were also asked about continuing experience with pediatric endoscopic procedures after the intensive training. RESULTS: There were 10 enrolled trainees, 9 men, average age, 34 (range, 29-41). The average number (range) of EGD and ileocolonoscopies that the 10 trainees had done before this training period was 52 (0-200) and 15 (0-20), respectively. The average number (range) of EGD, ileocolonoscopies and snare polypectomies per each trainee was 651.7 (485-814), 159.2 (130-195) and 25.8 (10-55), respectively, over 3 months: all trainees thus fulfilled all of the criteria of the minimal training requirements. All trainees also reached the required threshold in the cecal intubation rate (>90%). In addition, all trainees were able to perform pediatric endoscopic procedures alone after the intensive training period. CONCLUSIONS: Short-term intensive training for 3 months in an adult GI setting enabled pediatric GI trainees to acquire technical competence for pediatric endoscopic procedures.

A novel BMPR1A mutation affects mRNA splicing in juvenile polyposis syndrome.

BACKGROUND: Juvenile polyposis syndrome (JPS) is one of the hereditary polyposis syndromes caused by abnormal regulation of transforming growth factor ß signaling because of mutations in BMPR1A and SMAD4. Juvenile polyposis syndrome patients with SMAD4 mutations develop cardiovascular events, whereas those with BMPR1A usually do not. Analysis of genetic mutations in JPS patients can be helpful in devising suitable strategies for medical management. In this study, we demonstrate the pathogenicity of a novel intronic mutation in BMPR1A using mRNA extracted from colonic mucosa of a boy with JPS. METHODS: Genomic DNA extracted from peripheral blood and total RNA isolated from the colonic mucosa were used for DNA sequencing and reverse transcription polymerase chain reaction (RT-PCR) analyses, respectively. RESULTS: A 13-year-old boy, with no previous medical history, presented to the hospital complaining of bloody stools. Colonoscopy revealed multiple polyps in the colon, and the resected polyps were compatible with juvenile polyps. Sequencing analysis revealed a novel intronic mutation (c.778+5G>C) in BMPR1A. Reverse transcription polymerase chain reaction analysis of RNA extracted from the colonic mucosa showed an aberrant splicing form of BMPR1A. Trio analysis showed that his mother also had the same BMPR1A mutation. She was diagnosed with cancer of the cecum and polyposis of the colon at the age of 41. CONCLUSION: We demonstrate the presence of a novel BMPR1A intronic mutation that exhibits splicing abnormality in a family with JPS. Further research and development will help elucidate the genotype-phenotype relationship in JPS.

Endoscopic retrograde cholangiopancreatography and endoscopic ultrasound in children.

Gastrointestinal endoscopy is fundamental to diagnostic and therapeutic procedures in pediatric gastroenterology. In the decades since endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS) for hepatobiliary and pancreatic disease were introduced into clinical practice, there has been increasing interest in these procedures, and practice guidelines and position papers that clearly define the role of ERCP and EUS in children have been published. Based on the distinction of endoscopy between children and adults, this review focuses on the current state of ERCP and EUS procedures in children, including the types of endoscopes used in children, general anesthesia and radiation exposure, biliary and pancreatic indications, considerations of education and training for ERCP and EUS procedures in children, and expectations for development of endoscopes for children.

Castration induced browning in subcutaneous white adipose tissue in male mice.

We demonstrated that castration enhanced the expression of uncoupling protein 1 (Ucp1), a thermogenic protein, in brown adipose tissue (BAT) and subcutaneous (sc) white adipose tissue (WAT) in male mice. Castration of male mice increased body temperature and reduced body weight gain compared with those of sham-operated mice. BAT Ucp1 mRNA expression in castrated male mice was significantly higher than that in sham-operated mice. Histologically, cells with multilocular fat droplets were observed in the castrated inguinal scWAT. Immunohistochemical staining revealed that these cells positively reacted with the anti-Ucp1 antibody. The Ucp1-positive area near the inguinal lymph node in the castrated WAT was extensive compared with that of the sham-operated WAT. Castration-induced Ucp1 up-regulation in scWAT was suppressed by high-fat diet feeding. These findings suggest that thermogenesis by BAT activation and scWAT browning contribute to castration-induced inhibition of body weight gain. However, considering that the effect of castration was blunted by high-fat diet consumption, thermogenesis stimulation in response to castration is inhibited by chronic over-nutrition.

Gata3/Ruvbl2 complex regulates T helper 2 cell proliferation via repression of Cdkn2c expression.

GATA-binding protein 3 (Gata3) controls the differentiation of naive CD4 T cells into T helper 2 (Th2) cells by induction of chromatin remodeling of the Th2 cytokine gene loci, direct transactivation of Il5 and Il13 genes, and inhibition of Ifng. Gata3 also facilitates Th2 cell proliferation via additional mechanisms that are far less well understood. We herein found that Gata3 associates with RuvB-like protein 2 (Ruvbl2) and represses the expression of a CDK inhibitor, cyclin-dependent kinase inhibitor 2c (Cdkn2c) to facilitate the proliferation of Th2 cells. Gata3 directly bound to the Cdkn2c locus in an Ruvbl2-dependent manner. The defect in the proliferation of Gata3-deficient Th2 cells is rescued by the knockdown of Cdkn2c, indicating that Cdkn2c is a key molecule involved in the Gata3-mediated induction of Th2 cell proliferation. Ruvbl2-knockdown Th2 cells showed decreased antigen-induced expansion and caused less airway inflammation in vivo. We therefore have identified a functional Gata3/Ruvbl2 complex that regulates the proliferation of differentiating Th2 cells through the repression of a CDK inhibitor, Cdkn2c.

Development of a novel immunoassay specific for mouse intact proinsulin.

The blood concentration of intact proinsulin, but not total proinsulin, has been suggested to be a diagnostic marker for type 2 diabetes mellitus (T2DM), but a sensitive assay specific for rodent intact proinsulin is lacking. Here, a novel enzyme-linked immunosorbent assay (ELISA) for mouse intact proinsulin was developed. The developed ELISA detected mouse intact proinsulin with the working range of 8.3 to 2700pg/ml. Cross-reactivity with mouse split-32,33 proinsulin was approximately 100times lower than the reactivity with mouse intact proinsulin, and no cross-reactivity with mouse insulin was detected. The developed ELISA was sufficiently sensitive to detect low levels of intact proinsulin in normal mouse plasma. The measurement by the developed ELISA revealed that intact proinsulin was elevated in the plasma of type 2 diabetic db/db mice as mice aged, and the ratio of intact proinsulin/insulin in plasma was correlated with levels of glycated hemoglobin A1c as seen in T2DM patients. These results suggest that the plasma level of intact proinsulin, but not total proinsulin, is a sensitive marker for pancreatic dysfunction and the ensuring diabetic disease progression of db/db mice. This ELISA could aid nonclinical evaluation of therapeutic interventions in T2DM.

Activation of bystander CD8+ T cells in a pediatric patient with acute hepatitis E.

Most children with acute hepatitis A virus (HAV) or hepatitis E virus (HEV) infection are asymptomatic. Bystander CD8+ T-cell activation has garnered attention owing to its possible pathophysiological role in adult hepatitis. However, no reports have studied it in pediatric hepatitis. Herein, we describe the case of a three-year-old girl with acute hepatitis by HEV genotype 1. She had a history of Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infections, and HEV hepatitis occurred shortly after asymptomatic HAV infection. Peripheral immunophenotyping revealed activation of non-HEV-specific CD8+ T cells which include EBV-specific and CMV-specific CD8+ T cells, during the acute phase. While alanine-aminotransferase levels declined after admission, the total number of activated CD8+ T cells increased for four days after admission and decreased thereafter. In contrast, activation of EBV-specific and CMV-specific CD8+ T cells was almost at the maximal level at the time of admission, which suggest development of activated bystander CD8+ T cells in the early stage. This case highlights the significance of the bystander CD8+ T-cell activation even in pediatric hepatitis and the size of the CD8+ T cell memory pool in the individuals for the development of hepatitis, given the patient's history of infections with EBV, CMV and HAV.

A Case of Anorexia Nervosa with Focal Cortical Dysplasia.

Anorexia nervosa (AN) is a fatal condition associated with extreme underweight and undernutrition. It is more common in young females, with a female-to-male ratio of 10 : 1. Focal cortical dysplasia (FCD) is characterized by dysplasia of the cerebral cortex and is a common cause of pharmacoresistant epilepsy. However, FCD associated with AN has never been reported. We report the first case of AN in a 12-year-old male diagnosed with FCD-type 2 on head magnetic resonance imaging (MRI). He became concerned about lower abdominal distention and began reducing his food intake. He was admitted to our hospital after weight loss of 10 kg in a 1 year. Head MRI showed a localized high-signal area from the cortex to the white matter of the fusiform gyrus near the left hippocampus, with no associated decreased blood flow or electroencephalography (EEG) abnormalities. These findings were characteristic of FCD type II. In males with AN, the search for underlying disease is particularly important. The pathophysiology of the association between AN and FCD is unclear. However, both conditions are reportedly associated with autism spectrum disorder. Further cases are needed to clarify whether FCD is associated with eating disorders.

Optimization of enrichment conditions on TiO2 chromatography using glycerol as an additive reagent for effective phosphoproteomic analysis.

Metal oxide affinity chromatography (MOAC) represented by titanium dioxide (TiO2) chromatography has been used for phosphopeptide enrichment from cell lysate digests prior to mass spectrometry. For in-depth phosphoproteomic analysis, it is important for MOAC to achieve high phosphopeptide enrichment efficiency by optimizing purification conditions. However, there are some differences in phosphopeptide selectivity and specificity enriched by various TiO2 materials and procedures. Here, we report that binding/wash buffers containing polyhydric alcohols, such as glycerol, markedly improve phosphopeptide selectivity from complex peptide mixtures. In addition, the elution conditions combined with secondary amines, such as bis-Tris propane, made it possible to recover phosphopeptides with highly hydrophobic properties and/or longer peptide lengths. To assess the practical applicability of our improved method, we confirmed using PC3 prostate cancer cells. By combining the hydrophilic interaction chromatography (HILIC) with the optimized TiO2 enrichment method prior to LC-MS/MS analysis, over 8300 phosphorylation sites and 2600 phosphoproteins were identified. Additionally, some dephosphorylations of those were identified by treatment with dasatinib for a kinase inhibitor. These results indicate that our method is applicable to understanding the profiling of kinase inhibitors such as anticancer compounds, which will be useful for drug discovery and development.

Case report: Immunological characteristics of de novo ulcerative colitis in a child post COVID-19.

The pathological mechanisms of de novo inflammatory bowel disease (IBD) following SARS-CoV-2 infection are unknown. However, cases of coexisting IBD and multisystem inflammatory syndrome in children (MIS-C), which occurs 2-6 weeks after SARS-CoV-2 infection, have been reported, suggesting a shared underlying dysfunction of immune responses. Herein, we conducted the immunological analyses of a Japanese patient with de novo ulcerative colitis following SARS-CoV-2 infection based on the pathological hypothesis of MIS-C. Her serum level of lipopolysaccharide-binding protein, a microbial translocation marker, was elevated with T cell activation and skewed T cell receptor repertoire. The dynamics of activated CD8+ T cells, including T cells expressing the gut-homing marker α4ß7, and serum anti-SARS-CoV-2 spike IgG antibody titer reflected her clinical symptoms. These findings suggest that SARS-CoV-2 infection may trigger the de novo occurrence of ulcerative colitis by impairing intestinal barrier function, T cell activation with a skewed T cell receptor repertoire, and increasing levels of anti-SARS-CoV-2 spike IgG antibodies. Further research is needed to clarify the association between the functional role of the SARS-CoV-2 spike protein as a superantigen and ulcerative colitis.

Potential plasma biomarkers for progression of knee osteoarthritis using glycoproteomic analysis coupled with a 2D-LC-MALDI system.

BACKGROUND: Although osteoarthritis (OA) is a highly prevalent joint disease, to date, no reliable biomarkers have been found for the disease. In this study, we attempted to identify factors the amounts of which significantly change in association with the progression of knee OA. METHODS: A total of 68 subjects with primary knee OA were enrolled in the study. These subjects were followed up over an 18-month period, and plasma and serum samples were obtained together with knee radiographs every 6 months, i.e., 0, 6, 12 and 18 months after the enrollment. Progressors and non-progressors were determined from the changes on radiographs, and plasma samples from those subjects were subjected to N-glycoproteomic 2D-LC-MALDI analysis. MS peaks were identified, and intensities for respective peaks were compared between the progressors and non-progressors to find the peak intensities of which differed significantly between the two groups of subjects. Proteins represented by the chosen peaks were identified by MS/MS analysis. Expression of the identified proteins was evaluated in synovial tissues from 10 OA knee joints by in situ hybridization, western blotting analysis and ELISA. RESULTS: Among the subjects involved in the study, 3 subjects were determined to be progressors, and 6 plasma and serum samples from these subjects were subjected to the analysis together with another 6 samples from the non-progressors. More than 3000 MS peaks were identified by N-glycoproteomic 2D-LC-MALDI analysis. Among them, 4 peaks were found to have significantly different peak intensities between the progressors and non-progressors. MS/MS analysis revealed that these peaks represented clusterin, hemopexin, alpha-1 acid glycoprotein-2, and macrophage stimulating protein, respectively. The expression of these genes in OA synovium was confirmed by in situ hybridization, and for clusterin and hemopexin, by western blotting analysis and ELISA as well. CONCLUSIONS: In this study, 4 potential biomarkers were identified as potential prognostic markers for knee OA through N-glycoproteomic analysis. To the best of our knowledge, this is the first report for the use of glycoproteomic technology in exploring potential biomarkers for knee OA.

Kawasaki disease with dilatation of the common bile duct: A case report and review of literature.

BACKGROUND: Kawasaki disease (KD) is a syndrome that results in acute systemic vasculitis and is a major cause of acquired heart disease in developed countries. KD is diagnosed based on certain characteristic symptoms and echocardiogram results. It has been reported that abdominal ultrasound is of value in supporting the diagnosis of KD. Nevertheless, abdominal ultrasound is not a routine procedure in KD. Moreover, dilatation of the common bile duct (CBD) has been rarely reported in previous cases. CASE PRESENTATION: A 4-year-old boy presented with fever and markedly high transaminase level (aspartate aminotransferase, 5323 U/L; alanine aminotransferase, 1554 U/L). The patient was diagnosed as having KD based on characteristic symptoms and echocardiogram findings. Ultrasound revealed dilatation of the CBD as well as cervical lymphadenopathy resembling a cluster of grapes, thickening of the gallbladder wall, and increased periportal echogenicity throughout the liver parenchyma. The patient received initial treatment with intravenous immunoglobulin at day 4 of fever and second-line treatment with intravenous immunoglobulin and prednisolone because of recurrent fever on day 6. Dilatation of the CBD was improved from 6.6 mm on day 4 to 3.1 mm on day 8. Although re-dilatation was observed, it gradually diminished and normalized (4.3 mm on day 28, 4.0 mm on day 63, 3.3 mm on day 105, and 2.8 mm on day 182). CONCLUSION: This case highlights the usefulness of abdominal ultrasound and the importance of considering dilatation of the CBD as one of the complications of KD.