The human milk oligosaccharide disialyllacto-N-tetraose prevents necrotising enterocolitis in neonatal rats.

BACKGROUND: Necrotising enterocolitis (NEC) is one of the most common and fatal intestinal disorders in preterm infants. Breast-fed infants are at lower risk for NEC than formula-fed infants, but the protective components in human milk have not been identified. In contrast to formula, human milk contains high amounts of complex glycans. OBJECTIVE: To test the hypothesis that human milk oligosaccharides (HMO) contribute to the protection from NEC. METHODS: Since human intervention studies are unfeasible due to limited availability of HMO, a neonatal rat NEC model was used. Pups were orally gavaged with formula without and with HMO and exposed to hypoxia episodes. Ileum sections were scored blindly for signs of NEC. Two-dimensional chromatography was used to determine the most effective HMO, and sequential exoglycosidase digestions and linkage analysis was used to determine its structure. RESULTS: Compared to formula alone, pooled HMO significantly improved 96-hour survival from 73.1% to 95.0% and reduced pathology scores from 1.98 ± 1.11 to 0.44 ± 0.30 (p<0.001). Within the pooled HMO, a specific isomer of disialyllacto-N-tetraose (DSLNT) was identified to be protective. Galacto-oligosaccharides, currently added to formula to mimic some of the effects of HMO, had no effect. CONCLUSION: HMO reduce NEC in neonatal rats and the effects are highly structure specific. If these results translate to NEC in humans, DSLNT could be used to prevent or treat NEC in formula-fed infants, and its concentration in the mother's milk could serve as a biomarker to identify breast-fed infants at risk of developing this disorder.

Acute PR3-ANCA vasculitis in an asymptomatic COVID-19 teenager.

We present the case of an acute onset ANCA positive vasculitis in an asymptomatic COVID-19 infected teenager, resulting in significant colonic damage. The patient was initially diagnosed with Henoch-Schönlein purpura and presented with worsening symptoms with significant necrosis of her perineum and rectum requiring surgical debridement and diverting colostomy. As a part of her work-up, she tested positive for COVID-19 total IgG/IgM antibodies and ANCA antibodies. This case complements previously reported cases of COVID-19 induced autoimmune disease in children but is novel in describing extensive intestinal disease as a result of an autoimmune vasculitis in a child.

Further delineation of interstitial chromosome 6 deletion syndrome and review of the literature.

Interstitial deletions of chromosome 6q are a relatively rare finding. Deletions have ranged from the loss of a single band to larger deletions spanning multiple bands. The clinical phenotype varies, but some features commonly seen include cardiac anomalies, hypotonia, facial dysmorphism and mental retardation. To further delineate the syndrome, we report an infant with facial dysmorphism, ectrodactyly and tetralogy of Fallot owing to interstitial deletion 6q16.1-6q22.32. On array comparative genomic hybridization analysis, the deletion spanned from the 93 377 323rd base to the 127 650 582nd base on chromosome 6 [coordinates are based on Human Mar. 2006 (hg18) assembly of International Human Genome Sequencing Consortium]. A literature review identified 16 additional cases with overlapping interstitial deletions of chromosome 6q between q13 and q23.1. Genotype-phenotype correlations are considered.