Regulatory T Cells in Type 1 Autoimmune Pancreatitis

Autoimmune pancreatitis (AIP) is a newly recognized pancreatic disorder. Recently, International Consensus Diagnostic Criteria for AIP (ICDC) was published. In this ICDC, AIP was classified into Type 1 and Type 2. Patients with Type 1 AIP have several immunologic and histologic abnormalities specific to the disease, including increased levels of serum IgG4 and storiform fibrosis with infiltration of lymphocytes and IgG4-positive plasmacytes in the involved organs. Among the involved organs showing extrapancreatic lesions, the bile duct is the most common, exhibiting sclerosing cholangitis (IgG4-SC). However, the role of IgG4 is unclear. Recently, it has been reported that regulatory T cells (Tregs) are involved in both the development of various autoimmune diseases and the shift of B cells toward IgG4, producing plasmacytes. Our study showed that Tregs were increased in the pancreas with Type 1 AIP and IgG4-SC compared with control. In the patients with Type 1 AIP and IgG4-SC, the numbers of infiltrated Tregs were significantly positively correlated with IgG4-positive plasma cells. In Type 1 AIP, inducible costimulatory molecule (ICOS)+ and IL-10+ Tregs significantly increased compared with control groups. Our data suggest that increased quantities of ICOS+ Tregs may influence IgG4 production via IL-10 in Type 1 AIP

Extraordinary Optical Transmission by Hybrid Phonon–Plasmon Polaritons Using hBN Embedded in Plasmonic Nanoslits

Hexagonal boron nitride (hBN) exhibits natural hyperbolic dispersion in the infrared (IR) wavelength spectrum. In particular, the hybridization of its hyperbolic phonon polaritons (HPPs) and surface plasmon resonances (SPRs) induced by metallic nanostructures is expected to serve as a new platform for novel light manipulation. In this study, the transmission properties of embedded hBN in metallic one-dimensional (1D) nanoslits were theoretically investigated using a rigorous coupled wave analysis method. Extraordinary optical transmission (EOT) was observed in the type-II Reststrahlen band, which was attributed to the hybridization of HPPs in hBN and SPRs in 1D nanoslits. The calculated electric field distributions indicated that the unique Fabry–Pérot-like resonance was induced by the hybridization of HPPs and SPRs in an embedded hBN cavity. The trajectory of the confined light was a zigzag owing to the hyperbolicity of hBN, and its resonance number depended primarily on the aspect ratio of the 1D nanoslit. Such an EOT is also independent of the slit width and incident angle of light. These findings can not only assist in the development of improved strategies for the extreme confinement of IR light but may also be applied to ultrathin optical filters, advanced photodetectors, and optical devices

Giant Dirac point shift of graphene phototransistors by doped silicon substrate current

Graphene is a promising new material for photodetectors due to its excellent optical properties and high-speed response. However, graphene-based phototransistors have low responsivity due to the weak light absorption of graphene. We have observed a giant Dirac point shift upon white light illumination in graphene-based phototransistors with n-doped Si substrates, but not those with p-doped substrates. The source-drain current and substrate current were investigated with and without illumination for both p-type and n-type Si substrates. The decay time of the drain-source current indicates that the Si substrate, SiO2 layer, and metal electrode comprise a metal-oxide-semiconductor (MOS) capacitor due to the presence of defects at the interface between the Si substrate and SiO2 layer. The difference in the diffusion time of the intrinsic major carriers (electrons) and the photogenerated electron-hole pairs to the depletion layer delays the application of the gate voltage to the graphene channel. Therefore, the giant Dirac point shift is attributed to the n-type Si substrate current. This phenomenon can be exploited to realize high-performance graphene-based phototransistors

Perforation-Free Removal of Gastric Gastrointestinal Stromal Tumors: Endoscopic Inversion and Strangulation of Muscle layer and Resection (EISMR)

Endoscopic resection for GIST has become more widespread in recent years because it is less invasive than surgery. However, when endoscopic resection is performed, a full-layer resection of the gastric wall is often necessary, and extensive suturing is required if perforation occurs, which is a technically challenging procedure. Recently, we reported a new method called endoscopic inversion and strangulation of the muscle layer and resection (EISMR), which consists of endoscopically inverting the muscle layer into the gastric lumen and strangulating the muscle layer with a detachable snare, followed by resection. The study comprised five consecutive patients with gastric GIST ≤50 mm in diameter who underwent EISMR procedures. The main outcomes of the study were en bloc resection rate, R0 resection rate, procedure time, and complications. The results showed that all five patients successfully underwent complete resection without perforation, and the en bloc resection and R0 resection rates were 100%. The median procedure time was 93 min (range, 58–120 min), and there were no major complications. We concluded that EISMR would be a safe and effective technique for endoscopic resection of gastric GISTs and may be an alternative to surgery or endoscopic submucosal dissection

Viral Infection in Esophageal, Gastric, and Colorectal Cancer

The human gastrointestinal tract, which constitutes the digestive system, contains a large number of virus particles that maintain organizational homeostasis and health. Conversely, viral pathogens have also attracted attention for their involvement in the pathogenesis of certain cancers, including gastrointestinal cancers. To aid prevention and treatment of these cancers, the relevance of gastrointestinal viral factors as potential risk factors needs to be carefully investigated. This review summarizes and discusses the available literature on the relationship between the development of esophageal, gastric, and colorectal cancers and their corresponding viruses. This review reveals that research on the association between colorectal cancer and viruses, in particular, is still in its infancy compared to the association between HPV and esophageal cancer and between EBV and gastric cancer