Chronic active EBV infection with features of granulomatosis with polyangiitis

Herein, we report the case of a 13‐year‐old boy with multiple recurrent ulcers on his legs. He developed severe sinusitis at 10 years of age and had significant weight loss (6 kg) in the 2 months prior to admission. Histology of tissue biopsied from the ulcer indicated small vessel vasculitis and granulomatous inflammation. Given that these findings met the diagnostic criteria for granulomatosis with polyangiitis (GPA), he was treated with immunosuppressive agents. Further pathology, however, indicated Epstein–Barr virus (EBV)‐encoded RNA (EBER) in most lymphocytes in the same sample. The EBER‐positive lymphocytes were mainly CD4‐positive T cells. The EBV‐DNA load in the peripheral blood was also abnormally increased (1.0 × 10⁴ copies/μg DNA). Thus, the diagnosis was established as chronic active EBV infection (CAEBV). This case illustrates the necessity of careful differential diagnosis of CAEBV owing to its clinical resemblance and pathological overlap with GPA.     

Photo-induced in situ crosslinking of polymer brushes with dimethyl maleimide moieties for dynamically stimulating stem cell differentiation

We designed photo-crosslinkable polymer brushes with dimethylmaleimide moieties, in order to demonstrate dynamic stimulation of cell differentiation in mesenchymal stem cells (MSCs). The polymer brushes were synthesized by surface-initiated reversible addition fragmentation chain transfer polymerization using dimethylmaleimide ethyl methacrylate and methyl methacrylate on a chain transfer agent-immobilized glass surface. The polymer brushes were crosslinked by photodimerization of the dimethylmaleimide moieties within polymer chains with stem cells present on the surface. In order to evaluate the effects of in situ photo-induced crosslinking of the polymer brushes on gene expression of stem cells, human bone marrow MSCs were cultured under static and dynamic culture conditions for 7 days. Expression of the osteocalcin (Ocn) gene in MSCs was used as an indicator of osteoblast differentiation under dynamic culture conditions. Structural conversion from non-crosslinked polymer brushes to crosslinked polymer brushes increased the expression of Ocn by 1.4-fold in the presence of adhered cells, compared with non-crosslinked polymer brushes under static culture conditions. These results suggest that MSCs recognized surface conversion from non-crosslinked to crosslinked structures, which resulted in altered differentiation lineages. Therefore, photo-crosslinkable surfaces with dimethyl maleimide moieties are potential novel materials for dynamically stimulating MSC differentiation.     

Blue laser imaging identifies endoscopic findings corresponding to metachronous esophageal squamous cell carcinoma

Esophagus - This study aimed to evaluate endoscopic findings using non-magnifying blue laser imaging (BLI) to determine the risk factors for metachronous esophageal squamous cell carcinoma (ESCC)....