Error Estimates for First- and Second-Order Lagrange-Galerkin Moving Mesh Schemes for the One-Dimensional Convection-Diffusion Equation

A new moving mesh scheme based on the Lagrange-Galerkin method for the approximation of the one-dimensional convection-diffusion equation is studied. The mesh movement, which is prescribed by a discretized dynamical system for the nodal points, follows the direction of convection. It is shown that under a restriction of the time increment the mesh movement cannot lead to an overlap of the elements and therefore an invalid mesh. For the linear element, optimal error estimates in the $\ell^\infty(L^2) \cap \ell^2(H_0^1)$ norm are proved in case of both, a first-order backward Euler method and a second-order two-step method in time. These results are based on new estimates of the time dependent interpolation operator derived in this work. Preservation of the total mass is verified for both choices of the time discretization. Numerical experiments are presented that confirm the error estimates and demonstrate that the proposed moving mesh scheme can circumvent limitations that the Lagrange-Galerkin method on a fixed mesh exhibits.Comment: 27 pages, 3 figures, 4 table

A novel de novo SLC26A3 mutation causing congenital chloride diarrhea in a Japanese neonate

Abstract Background Congenital chloride diarrhea (CCD) is characterized by persistent chloride (Cl)‐rich diarrhea evident from birth. CCD is a rare autosomal recessive disorder caused by defects in the solute carrier family 26 member 3 (SLC26A3) gene, which encodes an intestinal Cl−/HCO3−, Na+‐independent exchanger. Various mutations of SLC26A3 have been described in CCD. However, no de novo mutations have been found to be responsible for CCD. Here we report the first such occurrence. Methods Clinical and laboratory findings during the perinatal period were obtained retrospectively from medical records. Mutations involving SLC26A3 were detected by Sanger sequencing. Results The male infant reported here was delivered at 29 weeks of gestation. Just after birth, he had watery diarrhea without meconium passage. High chloride concentrations in the diarrhea led to a diagnosis of CCD. Direct sequencing of all coding exons in SLC26A3 including exon‐intron boundaries disclosed 2 compound heterozygous mutations: c.382G>A, p.G128S and c.2063‐1g>t. The c. 2063‐1g>t mutation was confirmed in his mother's DNA, but c.382G>A, p.G128S was absent in both mother and father. Conclusion We concluded that c.382G>A, p.G128S represented a de novo mutation of SLC26A3, a very rare event in autosomal recessive disorders. To our knowledge, this is the first CCD case involving a de novo novel mutation of SLC26A3

Utility of Diagnostic Colonoscopy in Pediatric Intestinal Disease

Background: The roles and methods of diagnostic colonoscopy in pediatric patients were previously demonstrated. With advances in medical equipment and the increasing need for pediatric endoscopic diagnosis, we compared recent results with those previously reported. Methods: A retrospective analysis was conducted on pediatric patients aged ≤15 years, comparing those who underwent their first diagnostic colonoscopy between 1 January 2007 and 28 February 2015 with those who did so between 1 March 2015 and 28 February 2022 at Kurume University Hospital. Results: A total of 274 patients were included, including 110 in the previous study and 164 in the present study. The main indications were hematochezia in the previous study (63/110, 57.3%) and abdominal pain in the present study (64/164, 39.0%). Ulcerative colitis (74/274, 27.0%) was the most common diagnosis in both studies. The major difference from the previous study was an increase in the number of Crohn’s disease and eosinophilic gastrointestinal disorder cases. Bowel preparation with magnesium citrate was significantly increased across all ages in the present study (142/164, 86.6%). Midazolam + pentazocine was used for sedation in most cases (137/164, 83.5%). An ultrathin upper endoscope was mainly used in patients aged ≤6 years, while ultrathin colonoscopes were applied in patients aged 7–12 years. Conclusion: In the present study, appropriate changes were found in the roles and methods of diagnostic colonoscopy in pediatric patients compared to the previous study. The increasing trend of patients presenting with inflammatory bowel disease and eosinophilic gastrointestinal disorder worldwide indicates the importance of colonoscopy in infants and children

Infantile-onset inflammatory bowel disease in a patient with Hermansky-Pudlak syndrome: a case report

Abstract Background Hermansky-Pudlak syndrome (HPS) is a rare, genetically heterogeneous disorder that manifests oculocutaneous albinism together with bleeding diatheses that reflect a platelet storage pool deficiency. Ten genetic subtypes of this autosomal recessive condition have been described to date. Some patients with Hermansky-Pudlak syndrome type 1, 4, or 6 develop Crohn’s-like inflammatory bowel disease at any age including early childhood, but most often in adolescence or young adulthood. Here we report infantile-onset of inflammatory bowel disease in a patient with Hermansky-Pudlak syndrome type 1 who responded to infliximab. Case presentation A Japanese boy, the second child of non-consanguineous healthy parents, was born with chalky white skin, silvery-white hair, and gray eyes, representing oculocutaneous albinism. He developed frequent diarrhea and fever accompanied by weight loss at 6 months, and was diagnosed with Crohn’s-like inflammatory bowel disease based on the endoscopic finding of longitudinal ulcerations in the colon and the histopathologic finding of nonspecific chronic inflammation without granulomas at the age of 11 months. Treatment with an elemental diet, salazosulfapyridine, and corticosteroids failed to improve clinical or laboratory abnormalities, and the diarrhea became bloody. At 13 months he began treatment with infliximab, which produced marked improvement followed by clinical remission. Endoscopy at 20 months demonstrated healing of the colonic mucosa. At 22 months he is in sustained clinical remission receiving only infliximab. Because albinism with inflammatory bowel disease suggested Hermansky-Pudlak syndrome, we performed genetic screening using next-generation sequencing in a targeted gene panel analysis for primary immunodeficiency disease and/or inflammatory bowel disease. The patient proved to have a compound heterozygous mutation of the HPS1 gene resulting in Hermansky-Pudlak syndrome type 1. Conclusions We consider this report to be the first account of type 1 Hermansky-Pudlak syndrome with infantile-onset of inflammatory bowel disease. Early administration of infliximab was effective. We recommend next-generation sequencing for patients with very early-onset inflammatory bowel disease suspected to be monogenic

Clinicopathologic Features, Genetics, Treatment, and Long-Term Outcomes in Japanese Children and Young Adults with Benign Recurrent Intrahepatic Cholestasis: A Multicenter Study

Background: Few reports of benign recurrent intrahepatic cholestasis (BRIC) have focused on East Asian patients. We describe the clinicopathologic features, genetics, treatment, and outcomes in Japanese BRIC patients. Methods: We recruited patients with BRIC type 1 (BRIC-1) or 2 (BRIC-2) treated at four pediatric centers and one adult center between April 2007 and March 2022. Demographics, clinical course, laboratory results, molecular genetic findings concerning ATP8B1 and ABCB11 genes, histopathology, and treatment response were examined retrospectively. Results: Seven Japanese patients with BRIC were enrolled (four male, three female; four BRIC-1 and three BRIC-2). The median age at onset for BRIC-1 was 12 years; for BRIC-2, it was 1 month. Intermittent cholestatic attacks numbered from one to eight during the 11 years of median follow-up. Six patients received a mainstream education; only one patient attended special education. None developed cirrhosis. Three with BRIC-1 showed compound heterozygosity for a variant ATP8B1 gene, while one was heterozygous; two BRIC-2 patients showed compound heterozygosity in ABCB11 and one was heterozygous. Liver biopsy specimens obtained during cholestatic attacks showed fibrosis varying from none to moderate; inflammation was absent or mild. Rifampicin administered to three patients for cholestatic attacks was effective in all, as was cholestyramine in two of three. Conclusions: To our knowledge, this is the first East Asian multicenter study of BRIC patients. Onset age and number of cholestatic attacks varied. Rifampicin and cholestyramine were effective against attacks. No patient developed cirrhosis; most had normal growth and development. The long-term outcomes were satisfactory

Additional file 3: of Novel exonic mutation inducing aberrant splicing in the IL10RA gene and resulting in infantile-onset inflammatory bowel disease: a case report

Functional assay of the IL-10 receptor. (DOCX 14 kb

Utility of a rapid assay for prostaglandin E-major urinary metabolite as a biomarker in pediatric ulcerative colitis

Abstract Prostaglandin E-major urinary metabolite (PGE-MUM) is a urinary biomarker reflecting ulcerative colitis (UC) activity. This prospective observational study aimed to evaluate the usefulness of PGE-MUM via rapid chemiluminescent enzyme immunoassay in detecting endoscopic remission (ER) and histologic remission (HR) in pediatric UC (6–16 years) in comparison with fecal calprotectin (FCP). ER and HR were defined as Mayo endoscopic score (MES) of 0 and Matts’ histological grades (Matts) of 1 or 2, respectively. A total of 104 UC and 39 functional gastrointestinal disorder (FGID) were analyzed. PGE-MUM levels were significantly higher in the UC group than in the FGID group (P < 0.001). FCP levels were significantly elevated in the group without ER and HR than in the group with ER and HR (P < 0.001 and P = 0.001), whereas PGE-MUM levels were significantly higher in the group without ER compared to the group with ER (P < 0.001). No significant differences were noted in the AUCs for PGE-MUM and FCP in detecting ER and HR. Although PGE-MUM was inferior to FCP for the detection of HR, it might have the potential for application as a biomarker of endoscopic activity in pediatric UC owing to its noninvasive and rapid method