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Loss-of-function mutations in nucleotide-binding oligomerization domain 2 (NOD2) constitute the primary risk factors for Crohn’s disease. NOD2 is an intracellular sensor for muramyl dipeptide (MDP), a small molecule derived from the peptidoglycan layer of bacterial cell wall. Although NOD2 is involved in host immune responses, much attention has been paid to the involvement of NOD2 in the maintenance of intestinal homeostasis. Despite the fact that the proinflammatory cytokine and chemokine responses induced by NOD2 activation alone are weaker than those induced by toll-like receptors (TLRs), NOD2 plays a crucial role in host defense against invading pathogens and in the regulation of immune responses. Recent studies have highlighted the importance of negative regulatory functions of NOD2 in TLRs-mediated proinflammatory cytokine responses. MDP-mediated activation of NOD2 induces interferon regulatory factor 4 (IRF4) expression, thereby suppressing nuclear factor-κB-dependent colitogenic cytokine responses through the inhibition of Lys(K)63-linked polyubiquitination on receptor-interacting serine/threonine protein kinase 2. MDP-mediated activation of NOD2 also downregulates TLR9-induced type I IFN responses by inhibiting the K63-linked polyubiquitination of TNF receptor-associated factor 3 via deubiquitinating enzyme A (DUBA) expression. Thus, NOD2 exerts dual negative regulation of TLRs-mediated proinflammatory cytokine and type I IFN responses by inducing the expression of IRF4 and DUBA, respectively. In this review, we summarize the molecular mechanisms whereby NOD2 activation suppresses TLRs-mediated proinflammatory and type I IFN responses. In addition, we discuss the clinical relevance of the NOD2-mediated negative regulation of TLRs in inflammatory bowel disease.

Exploration rovers have difficulty moving underground because the drag force from the ground restricts their movement; this hinders underground exploration. This study aimed to address this challenge. We posit a hypothesis that the rover can move underground by imparting vibration to the ground and changing the drag force. To validate this hypothesis, a testbed that moves underground was developed, and the drag force when imparting vibration was investigated. The results revealed that the drag force while imparting vibration is smaller than that after imparting vibration, and we accordingly devised the operation for moving underground. The proposed operation causes bias of the drag force by imparting vibration to make the testbed move in the direction of the small drag force. The effectiveness of the proposed method was assessed through an experiment wherein the testbed was set to move underground. The experimental results demonstrate the superiority of the proposed method, as the movement distance achieved with vibration is considerably greater than that without vibration. The findings validate the hypothesis that using vibration for underground motion is effective in improving mobility and provides valuable insights into the design of robots for underground motion.

Abstract Although prednisolone treatment is effective in Cronkhite–Canada syndrome (CCS), its mechanisms of action are poorly understood. We performed analyses of cytokine expression and fecal microbiota in a patient with the concurrent occurrence of CCS and rectal cancer, in whom regression of polyposis was achieved by prednisolone. Regression of CCS polyps was accompanied by downregulation of proinflammatory cytokine expression and alterations in microbiota composition; a decrease in Bacteroides fragilis and Peptostreptococcus anaerobius with the promotion of inflammation. We could not completely exclude the possibility that alterations in fecal microbiota composition might be influenced by the presence of advanced cancer. However, this case suggests that the administration of PSL might lead to the regression of CCS polyps through alterations in gut microbiota composition and suppression of proinflammatory cytokine responses.

Abstract In recent years, robots with leg mechanisms have received considerable attention as high-running planetary exploration rovers. Rovers undertaking planetary exploration require outstanding running performance to travel on loose ground on which they mostly slip and hardly move forward. The movement of the rover easily deforms the surface of loose ground. This problem can be solved by increasing the bearing capacity. The bearing capacity, the resistance force exerted on the rover legs when they make contact with the ground, needs to be sufficiently large to prevent legged rovers from slipping on loose ground. The bearing capacity can be increased by compaction of the ground by imparting vibrations. This study investigates the relationship between the bearing capacity in the horizontal direction and vibration parameters because this relationship offers valuable information for improving the running performance of legged rovers. First, we investigated the effect of changing the vibration parameters on the bearing capacity. Our experimental results show that the bearing capacity is related to vibration acceleration. These results suggest that the bearing capacity can be estimated from the vibration acceleration. Next, the frequency and amplitude were compared as vibration parameters to devise an efficient method for increasing the bearing capacity. The results of these experiments showed that high-amplitude vibrations increase the bearing capacity to a greater extent than high-frequency vibrations. The reason is that high-amplitude vibrations generate larger additional vibrations by the collision between the rod and the ground than high-frequency vibrations. This knowledge is valuable for selecting a suitable vibration that can efficiently increase the bearing capacity. This study suggests a method of facilitating further planetary exploration using legged rovers.

Abstract Background and Aim A multicenter, open‐label randomized Phase II trial was conducted to determine whether low‐dose gemcitabine plus nab‐paclitaxel (GnP) could improve tolerability and show equivalent efficacy to the standard‐dose GnP for elderly patients with metastatic pancreatic cancer. Methods Consecutive patients aged ≥65 years with metastatic pancreatic cancer who presented at one of four Japanese referral centers between November 2016 and January 2021 were enrolled. The 60 patients were randomly assigned to low‐ or standard‐dose groups with a 1:1 ratio. Patients in the low‐dose GnP group received gemcitabine at a dose of 250 mg/m2 and nab‐paclitaxel at 125 mg/m2. Results Low‐dose GnP significantly decreased the rate of cases requiring dose reduction (16.7% vs 63.3%). The response rate (36.7% vs 33.3%) and progression‐free survival (7.3 vs 8 months) were comparable between the low‐ and standard‐dose groups as determined by independent review. The difference in the median overall survival between the two groups was not significant (7.9 vs 12 months). The proportion of patients with hematologic and non‐hematologic treatment‐related adverse events was comparable between the two groups. Conclusion Low‐dose GnP had an equivalent efficacy to conventional therapy; however, it did not reduce adverse events.

IntroductionIntrapancreatic activation of trypsinogen caused by alcohol or high-fat intake and the subsequent autodigestion of the pancreas tissues by trypsin are indispensable events in the development of acute pancreatitis. In addition to this trypsin-centered paradigm, recent studies provide evidence that innate immune responses triggered by translocation of intestinal bacteria to the pancreas due to intestinal barrier dysfunction underlie the immunopathogenesis of acute pancreatitis. Although severe acute pancreatitis is often associated with pancreatic colonization by fungi, the molecular mechanisms linking fungus-induced immune responses to the development of severe acute pancreatitis are poorly understood. Leucine-rich repeat kinase 2 (LRRK2) is a multifunctional protein that mediates innate immune responses to fungi and bacteria. Mutations in Lrrk2 is a risk factor for Parkinson’s disease and Crohn’s disease, both of which are driven by innate immune responses to gut organisms.DiscussionIn this Minireview article, we discuss how activation of LRRK2 by the recognition of fungi induces severe acute pancreatitis.

Clostridium perfringens bacteremia is a rare but rapidly fatal condition, especially in patients exhibiting massive intravascular hemolysis (MIH), gas gangrene, and septic shock. Herein, we present an autopsy case of C. perfringens septicemia exhibiting MIH, gas gangrene, and cytokine storm. The patient was an 84-year-old female with a history of biliary reconstruction surgery for congenital biliary dilatation. She developed MIH, elevated inflammatory mediator levels, thrombocytopenia, and coagulopathy. She went into shock within 1 h of the presentation and died within a few hours. Rapid progression was associated with the transformation of liver abscesses into gas-filled abscesses on computed tomography scan, suggesting the rapid outgrowth of gas-producing bacteria. The patient was finally diagnosed with MIH and gas gangrene due to C. perfringens infection based on the presence of this bacterium in the blood and bile. On autopsy, gas gangrene was observed in almost all organs, originating from the bile duct. Polymerase chain reactions targeting C. perfringens toxins identified the isolated bacterium as C. perfringens type A expressing α-toxin (CPA), perfringolysin O (PFO), and collagenase (ColA). Elevated interleukin 6 and tumor necrosis factor-α expression levels were observed in the serum, and such proinflammatory responses were partially mediated by Toll-like receptor 2. This study elucidated the association between the toxin profiles of clinically isolated C. perfringens and the host cytokine responses in the patient.

Abstract To compare the behavioral roles of biogenic amines in the males of primitive and advanced eusocial bees, we determined the levels of dopamine- and octopamine-related substances in the brain, and the behavioral effects of these monoamines by drug injection in the primitive eusocial bumble bee, Bombus ignitus. The levels of dopamine and its precursors in the brain peaked at the late pupal stage, but the dopamine peak extended to adult emergence. The tyramine and octopamine levels increased from the mid-pupal to adult stages. The locomotor and flight activities, and light preference increased with age. Injection of octopamine and its receptor antagonist had significant effects on the locomotor and flight activities, whereas dopamine injection did not, indicating that these activities can be regulated by the octopaminergic system. We also determined the dynamics of dopamine-related substances in honey bee (Apis mellifera) drones. The changes in the dopamine level in the brains of honey bee drones exhibited two peaks from the pupal to adult stages, whereas the bumble bee males had only one peak. These are consistent with the behavioral functions of dopamine in honey bee drones and ineffectiveness of dopamine injection at the adult stage in bumble bee males.

Hepatocytes and liver-resident antigen-presenting cells are exposed to microbe-associated molecular patterns (MAMPs) and microbial metabolites, which reach the liver from the gut via the portal vein. MAMPs induce innate immune responses via the activation of pattern recognition receptors (PRRs), such as toll-like receptors (TLRs), nucleotide-binding oligomerization domain 1 (NOD1), and NOD2. Such proinflammatory cytokine responses mediated by PRRs likely contribute to the development of chronic liver diseases and hepatocellular carcinoma (HCC), as shown by the fact that activation of TLRs and subsequent production of IL-6 and TNF-α is required for the generation of chronic fibroinflammatory responses and hepatocarcinogenesis. Similar to TLRs, NOD1 and NOD2 recognize MAMPs derived from the intestinal bacteria. The association between the activation of NOD1/NOD2 and chronic liver diseases is poorly understood. Given that NOD1 and NOD2 can regulate proinflammatory cytokine responses mediated by TLRs both positively and negatively, it is likely that sensing of MAMPs by NOD1 and NOD2 affects the development of chronic liver diseases, including HCC. Indeed, recent studies have highlighted the importance of NOD1 and NOD2 activation in chronic liver disorders. Here, we summarize the roles of NOD1 and NOD2 in hepatocarcinogenesis and liver injury.

Acute pancreatitis is a common emergent disorder, a significant population of which develops the life-threatening condition, called severe acute pancreatitis (SAP). It is generally accepted that bacterial infection is associated with the development and persistence of SAP. In addition to bacterial infection, recent clinical studies disclosed a high incidence of fungal infection in patients with SAP. Moreover, SAP patients with fungal infection exhibit a higher mortality rate than those without infection. Although these clinical studies support pathogenic roles played by fungal infection in SAP, beneficial effects of prophylactic anti-fungal therapy on SAP have not been proved. Here we summarize recent clinical findings as to the relationship between fungal infection and the development of SAP. In addition, we discuss molecular mechanisms accounting for the development of SAP in the presence of fungal infection.

BackgroundPancreatic neuroendocrine carcinoma (PanNEC) is a rare disease entity with rapid progression and poor prognosis. Here, we report a PanNEC case with unique morphological features mimicking intraductal papillary mucinous carcinoma.Case presentationA 69-year-old Japanese man was referred to our hospital for further evaluation of weight loss and deterioration of diabetes mellitus. Contrast-enhanced computed tomography showed a solid and cystic mass with hypo-enhancement at the tail of the pancreas. The main pancreatic duct (MPD) was diffusely dilated without obstruction, accompanied by marked parenchymal atrophy. Multiple peritoneal and omental nodules were observed, suggesting tumor dissemination. Endoscopic retrograde cholangiopancreatography revealed that the mass correlated with the dilated MPD. During pancreatography, a large amount of mucus was extruded from the pancreatic orifice of the ampulla. Based on these imaging findings, intraductal papillary mucinous carcinoma was suspected. Per-oral pancreatoscopy (POPS)-guided tumor biopsies were conducted for the lesion's solid components. Histopathological examination of the biopsied material confirmed small-cell-type PanNEC with a Ki-67 labeling index of 90%. Due to his condition's rapid decline, the patient was given the best supportive care and died 28 days after diagnosis.ConclusionAlthough rare, PanNEC, which correlates with the MPD and is accompanied by marked dilation of the MPD, does exist as one phenotype. In such cases, POPS-guided biopsy could be a useful diagnostic modality.

Abstract Immune checkpoint inhibitors (ICIs) targeting programmed cell death 1 (PD-1) and cytotoxic T-lymphocyte antigen-4 (CTLA-4) are widely used to treat advanced metastatic cancers. Neutralisation of PD-1 or CTLA-4 by ICIs results in immune-related adverse events (irAEs). The clinicopathological features of twelve patients with hepatic irAEs were evaluated and compared to those of ten patients with autoimmune hepatitis (AIH) or graft-versus-host disease (GVHD). No significant difference was seen in serum levels of transaminases, whereas serum levels of IgG and anti-nuclear antibody were higher in patients with AIH than in those with GVHD or hepatic irAEs. Inflammation was limited to the liver lobes in patients with GVHD or hepatic irAEs, whereas patients with AIH exhibited both portal and lobular inflammation. Immunohistochemical analyses revealed a predominant infiltration of CD8+ T cells and defective accumulation of regulatory T cells (Tregs) expressing forkhead box p3 (FOXP3) in the lobular areas of patients with hepatic irAEs and GVHD. In contrast, periportal lesions of patients with AIH were characterised by an infiltration of CD4+ T cells, CD8+ T cells, CD20+ B cells, and FOXP3+ Tregs. Overall, the activation of CD8+ T cells in the absence of activation of Tregs potentially underlies the immunopathogenesis of hepatic irAEs.

Efficient protection against coronavirus disease 2019 (COVID-19) has been achieved by immunization with mRNA-based vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, efficient immune responses against this novel virus by vaccination are accompanied by a wide variety of side effects. Indeed, flares or new-onset of autoimmune disorders have been reported soon after the COVID-19 vaccination. Although pro-inflammatory cytokine responses play pathogenic roles in the development of autoimmunity, cytokines charactering COVID-19 vaccination-related autoimmune responses have been poorly understood. Given that mRNA derived from COVID-19 vaccine is a potent inducer for pro-inflammatory cytokine responses, these cytokines might mediate autoimmune responses after COVID-19 vaccination. Here we report a case with new-onset rheumatoid arthritis (RA) following COVID-19 vaccination. Serum concentrations not only of arthrogenic cytokines, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), but also of type I interferon (IFN) were elevated at the active phase in this case. Induction of remission by methotrexate and tocilizumab was accompanied by a marked reduction in serum concentrations of type I IFN, IL-6, and TNF-α. These results suggest that production of type I IFN, IL-6, and TNF-α induced by COVID-19 vaccination might be involved in this case with new-onset RA.

Abstract Objectives The endoscopic bilateral stent‐in‐stent (SIS) deployment is a challenging procedure. Such difficulty is mainly caused by sticking of the tip of the delivery sheath into the self‐expandable metal stents (SEMSs) mesh, requiring an additional dilating procedure. Herein, we assessed the clinical results of using cross‐wired metal stent for endoscopic bilateral SIS deployment (BONASTENT M‐Hilar) in patients with malignant hilar biliary obstruction (MHBO) in both high‐volume and non‐high‐volume centers. Methods We prospectively enrolled consecutive patients with MHBO between February 2016 and December 2018 at eight centers. Results Forty‐six patients were enrolled during the study period. The proportions of technical success were 93.5% (43/46) and clinical success (CS) on intention‐to‐treat and per‐protocol analyses were 91.3% (42/46) and 93.0% (40/43), respectively. The proportion of an additional dilating procedure during the primary procedure was 50.0% (23/46). Recurrent biliary obstruction (RBO) on intention‐to‐treat analysis occurred in 32.6% (15/46) of cases. Almost all of the events were caused by stent ingrowth (14/15). The median survival time and time to RBO were 255 and 349 days, respectively. The probability of stent patency at 3, 6, and 12 months was 86.5%, 63.9%, and 47.6%, respectively. Conclusions The cross‐wired metal stent had excellent technical and CS, although non‐high‐volume centers were included in this study (UMIN000021441).

IL-33 is a pleiotropic cytokine that promotes inflammation and fibrosis. IL-33 is produced by a broad range of cells, including antigen-presenting cells (APCs), epithelial cells, and fibroblasts. IL-33 produced by the innate immune cells has been shown to activate pro-inflammatory T helper type 1 (Th1) and T helper type 2 (Th2) responses. The intestinal barrier and tolerogenic immune responses against commensal microbiota contribute to the maintenance of gut immune homeostasis. Breakdown of tolerogenic responses against commensal microbiota as a result of intestinal barrier dysfunction underlies the immunopathogenesis of inflammatory bowel diseases (IBD) and pancreatitis. Recent studies have provided evidence that IL-33 is an innate immune cytokine that bridges adaptive Th1 and Th2 responses associated with IBD and pancreatitis. In this Mini Review, we discuss the pathogenic roles played by IL-33 in the development of IBD and pancreatitis and consider the potential of this cytokine to be a new therapeutic target.

The purpose of the present study was to experimentally confirm the thermodynamic correlation between the intrinsic liquid–liquid phase separation (LLPS) concentration (S0LLPS) and crystalline solubility (S0c) of drug-like molecules. Based on the thermodynamic principles, the crystalline solubility LLPS concentration melting point (Tm) equation (CLME) was derived (log10S0C=log10S0LLPS−0.0095Tm−310 for 310 K). The S0LLPS values of 31 drugs were newly measured by simple bulk phase pH-shift or solvent-shift precipitation tests coupled with laser-assisted visual turbidity detection. To ensure the precipitant was not made crystalline at log10S0C values showed a good correlation (root mean squared error: 0.40 log unit, absolute average error: 0.32 log unit).

Collagenous colitis (CC), a prototypical microscopic colitis, is a chronic inflammatory disorder of the colon. The diagnosis of CC depends on the pathological examination. The colonic mucosa of patients with CC is characterized by the presence of a substantially thickened collagen band (>10μm) under the surface epithelium. In addition, intraepithelial and lamina propria lymphocytes are markedly increased in patients with CC. However, the roles played by the lymphocytes accumulating in the colonic mucosa of patients with CC are poorly defined. Recent studies indicate that T cells infiltrating the colonic mucosa of patients with CC are mainly represented by CD4+ T cells, CD8+ T cells, and forkhead box P3 (FOXP3)+ regulatory T cells (Tregs). Given that activation of CD4+/CD8+ T cells and FOXP3+ Tregs usually mediates pro-inflammatory and anti-inflammatory responses, respectively, alterations in the colonic numbers of these adaptive T cells might be related to the resolution of colitis in patients with CC. We determined alterations in the composition of colonic T cells by extensive immunohistochemical (IHC) analyses in a case of CC successfully treated with budesonide and metronidazole. Colonic lamina propria immune cells mainly comprised CD3+ T cells, CD4+ T cells, CD8+ T cells, CD68+ macrophages, and FOXP3+ Tregs, but not CD20+ B cells or myeloperoxidase (MPO)+ granulocytes in the active phase. During remission, the numbers of CD3+ T cells, CD4+ T cells, CD8+ T cells, and CD68+ macrophages did not change significantly in the colonic lamina propria, whereas FOXP3+ Tregs were markedly decreased, suggesting that induction of remission was achieved in a Treg-independent manner. Thus, our study indicates that accumulation of FOXP3+ Tregs in the colonic mucosa of patients with CC might be a counter-regulatory mechanism reflecting persistent inflammation and that induction of remission might be achieved without activation of Tregs.

Although plasmacytoid dendritic cells (pDCs) able to produce large amounts of type 1 interferons (IFN-I) play beneficial roles in host defense against viral infections, excessive activation of pDCs, followed by robust production of IFN-I, causes autoimmune disorders including systemic lupus erythematosus (SLE) and psoriasis. Autoimmune pancreatitis (AIP), which is recognized as a pancreatic manifestation of systemic immunoglobulin G4-related disease (IgG4-RD), is a chronic fibroinflammatory disorder driven by autoimmunity. IgG4-RD is a multi-organ autoimmune disorder characterized by elevated serum concentrations of IgG4 antibody and infiltration of IgG4-expressing plasmacytes in the affected organs. Although the immunopathogenesis of IgG4-RD and AIP has been poorly elucidated, recently, we found that activation of pDCs mediates the development of murine experimental AIP and human AIP/IgG4-RD via the production of IFN-I and interleukin-33 (IL-33). Depletion of pDCs or neutralization of signaling pathways mediated by IFN-I and IL-33 efficiently inhibited the development of experimental AIP. Furthermore, enhanced expression of IFN-I and IL-33 was observed in the pancreas and serum of human AIP/IgG4-RD. Thus, AIP and IgG4-RD share their immunopathogenesis with SLE and psoriasis because in all these conditions, IFN-I production by pDCs contributes to the pathogenesis. Because the enhanced production of IFN-I and IL-33 by pDCs promotes chronic inflammation and fibrosis characteristic for AIP and IgG4-RD, neutralization of IFN-I and IL-33 could be a new therapeutic option for these disorders. In this Mini Review, we discuss the pathogenic roles played by the pDC-IFN-I-IL-33 axis and the development of a new treatment targeting this axis in AIP and IgG4-RD.

Behçet's disease (BD) is a rare inflammatory condition characterized by oral and genital ulcers, skin lesions, as well as ophthalmological, neurological, and gastrointestinal manifestations. BD involving the gastrointestinal tract is known as intestinal BD. The mucosa of the gastrointestinal tract of patients with intestinal BD exhibits enhanced levels of proinflammatory cytokines, such as IL-1β, IL-6, and TNF-α. These proinflammatory cytokines play pathogenic roles in the development of BD, as evidenced by the fact that biologics targeting these cytokines effectively induce BD remission. It should be noted, however, that the molecular mechanisms by which the blockade of these cytokines suppresses chronic inflammatory responses in BD are poorly understood. Herein, we report a case of intestinal BD resistant to prednisolone that was successfully treated with infliximab (IFX). The induction of remission by IFX was accompanied by a marked elevation of IL-6 and forkhead box P3 (FOXP3) at mRNA level. This case suggests that induction of remission by IFX is mediated not only by the suppression of TNF-α-mediated signaling pathways, but also by the promotion of IL-6 expression and accumulation of regulatory T cells expressing FOXP3.

Double expressor lymphoma (DEL), defined as overexpression of BCL2 and MYC, is an aggressive subtype of diffuse large B cell lymphoma (DLBCL). Here we report a case of a 64-year-old female diagnosed with abdominal DEL transformed from jejunum follicular lymphoma (FL). 18F-fluorodeoxyglucose (FDG)-positron emission tomography showed diffuse accumulation of FDG into the peritoneum and small bowel wall. Double balloon-assisted enteroscopy revealed whitish submucosal tumors in the proximal jejunum. Aggregation of atypical lymphocytes positive for CD20, CD79a, and BCL2 was seen in the jejunal biopsy samples. These atypical lymphocytes were monoclonal since cell surface expression of Ig light chains was limited to κ chain by flow-cytometry. Thus, immunohistochemical and flowcytometric analyses data were consistent with FL of the jejunum. Neoplastic lymphocytes obtained from ascites were positive for CD10, CD20, CD79a, BCL2, and BCL6. Fluorescence in situ hybridization (FISH) showed formation of BCL2/IgH fusion gene and extra copies of MYC, the former of which is a characteristic chromosomal abnormality of FL. These genetic alterations and protein expression profiles of ascitic fluid cells were consistent with those of DEL transformed from FL. Given that a significant population of patients with indolent FL of the gastrointestinal tract developed into aggressive DLBCL, it is likely that primary FL of the jejunum transformed into the abdominal aggressive DEL in this case. This case is unique in that concurrent occurrence of FL and DEL was confirmed by immunohistochemical and FISH analyses and that abdominal DEL transformed from jejunal FL was highly suspected.

Inflammatory bowel diseases (IBDs) are becoming more frequent worldwide. A significant fraction of patients with IBD are refractory to various types of therapeutic biologics and small molecules. Therefore, identification of novel therapeutic targets in IBD is required. Receptor-interacting serine/threonine kinase 2 (RIPK2), also known as receptor-interacting protein 2 (RIP2), is a downstream signaling molecule for nucleotide-binding oligomerization domain 1 (NOD1), NOD2, and Toll-like receptors (TLRs). RIPK2 is expressed in antigen-presenting cells, such as dendritic cells and macrophages. Recognition of microbe-associated molecular patterns by NOD1, NOD2, and TLRs leads to the interaction between RIPK2 and these innate immune receptors, followed by the release of pro-inflammatory cytokines such as TNF-α, IL-6, and IL-12/23p40 through the activation of nuclear factor kappa B and mitogen-activated protein kinases. Thus, activation of RIPK2 plays a critical role in host defense against microbial infections. Recent experimental and clinical studies have provided evidence that activation of RIPK2 is involved in the development of autoimmune diseases, especially IBDs. In addition, the colonic mucosa of patients with IBD exhibits enhanced expression of RIPK2 and associated signaling molecules. Furthermore, the blockage of RIPK2 activation ameliorates the development of experimental murine colitis. Thus, activation of RIPK2 underlies IBD immunopathogenesis. In this review, we attempt to clarify the roles played by RIPK2 in the development of IBD by focusing on its associated signaling pathways. We also discuss the possibility of using RIPK2 as a new therapeutic target in IBD.

Autoimmune pancreatitis (AIP) is a chronic fibro-inflammatory disorder of the pancreas. Recent clinicopathological analysis revealed that most cases of AIP are pancreatic manifestations of systemic IgG4-related disease (IgG4-RD), a newly established disease characterized by enhanced IgG4 antibody responses and the involvement of multiple organs. Although the immuno-pathogenesis of AIP and IgG4-RD has been poorly defined, we recently showed that activation of plasmacytoid dendritic cells (pDCs) with the ability to produce large amounts of IFN-α and IL-33 mediates chronic fibro-inflammatory responses in experimental and human AIP. Moreover, M2 macrophages producing a large amount of IL-33 play pathogenic roles in the development of human IgG4-RD. Interestingly, recent studies including ours provide evidence that compositional alterations of gut microbiota are associated with the development of human AIP and IgG4-RD. In addition, intestinal dysbiosis plays pathological roles in the development of chronic pancreatic inflammation as dysbiosis mediates the activation of pDCs producing IFN-α and IL-33, thereby causing experimental AIP. In this Mini Review, we focus on compositional alterations of gut microbiota in AIP and IgG4-RD to clarify the mechanisms by which intestinal dysbiosis contributes to the development of these disorders.

Convolutional neural networks (CNNs) are widely used for artificial intelligence (AI)-based image classification. Residual network (ResNet) is a new technology that facilitates the accuracy of image classification by CNN-based AI. In this study, we developed a novel AI model combined with ResNet to diagnose colorectal polyps. In total, 127,610 images consisting of 62,510 images with adenomatous polyps, 30,443 with non-adenomatous hyperplastic polyps, and 34,657 with healthy colorectal normal mucosa were subjected to deep learning after annotation. Each validation process was performed using 12,761 stored images of colorectal polyps by a 10-fold cross validation. The efficacy of the ResNet system was evaluated by sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy. The sensitivity, specificity, PPV, NPV, and diagnostic accuracy for adenomatous polyps at WLIs were 98.8%, 94.3%, 90.5%, 87.4%, and 92.8%, respectively. Similar results were obtained for adenomatous polyps at narrow-band imagings (NBIs) and chromoendoscopy images (CEIs) (NBIs vs. CEIs: sensitivity, 94.9% vs. 98.2%; specificity, 93.9% vs. 85.8%; PPV, 92.5% vs. 81.7%; NPV, 93.5% vs. 99.9%; and overall accuracy, 91.5% vs. 90.1%). The ResNet model is a powerful tool that can be used for AI-based accurate diagnosis of colorectal polyps.

Purpose of our research is to improve the movement performance of small leg typed rovers using effects caused by vibration propagation. When the loose ground is given vibration, there are two effects. One is to increase density of the loose ground, and the other is to increase sinkage of legs. If the density of the ground is increased by vibration/stop, the rovers are not easy to slip. This means that the shearing strength becomes large since the loose ground is given effect of vibration/stop. Moreover, when the sinkage of legs are increased, the supporting force becomes large. The difference of ground before and after vibrating are confirmed by implemented some experiments such as measurement of shearing strength, sinkage and earth pressure. As results, the value of shearing strength and sinkage of leg were increased after vibration. Also, the value of earth pressure was increased after vibration. Furthermore, these effects given by vibration/stop are confirmed using multi-legged rover. In experimental results, walking distance of proposed rovers with vibration was longer than one without vibration. From theses experimental results, we could get knowledge that the method using vibration/stop was very effective for the leg typed rovers.

Dopamine has multiple functions in the modulation of social behavior and promotion of reproduction in eusocial Hymenoptera. In the honey bee, there are sex-specific differences in the regulation of dopamine production in the brain. These different dopaminergic systems might contribute to the maintenance of sex-specific behaviors and physiology. However, it is still not fully understood how the dopaminergic system in the brain is regulated by endocrinal factors and social stimuli in the colony. In this review, we focus on the regulation of dopamine production in queens, workers, and males in the honey bee. Dopamine production can be controlled by queen substance, juvenile hormone, and exogenous tyrosine from food. Queens can control dopamine production in workers via queen substance, whereas workers can manipulate the supply of tyrosine, a precursor of dopamine, to queens and males. The regulation of dopamine production through social interaction might affect the reproductive states of colony members and maintain sex-specific behaviors in unpredictable environments.

Background: Pancreatic cancer (PC) exhibits extremely rapid growth; however, it remains largely unknown whether the early stages of PC also exhibit rapid growth speed equivalent to advanced PC. This study aimed to investigate the natural history of early PCs through retrospectively assessing pre-diagnostic images. Methods: We examined the data of nine patients, including three patients with carcinoma in situ (CIS), who had undergone magnetic resonance cholangiopancreatography (MRCP) to detect solitary main pancreatic duct (MPD) stenosis >1 year before definitive PC diagnosis. We retrospectively analyzed the time to diagnosis and first-time tumor detection from the estimated time point of first-time MPD stenosis detection without tumor lesion. Results: The median tumor size at diagnosis and the first-time tumor detection size were 14 and 7.5 mm, respectively. The median time to diagnosis and first-time tumor detection were 26 and 49 months, respectively. Conclusions: No studies have investigated the PC history, especially that of early PCs, including CIS, based on the initial detection of MPD stenosis using MRCP. Assessment of a small number of patients showed that the time to progression can take several years in the early PC stages. Understanding this natural history is very important in the clinical setting.

Even in the current era of metagenomics, the interpretation of nucleotide sequence data is primarily dependent on knowledge obtained from a limited number of microbes isolated in pure culture. Thus, it is of fundamental importance to expand the variety of strains available in pure culture, to make reliable connections between physiological characteristics and genomic information. In this study, two sulfur oxidizers that potentially represent two novel species were isolated and characterized. They were subjected to whole-genome sequencing together with 7 neutrophilic and chemolithoautotrophic sulfur-oxidizing bacteria. The genes for sulfur oxidation in the obtained genomes were identified and compared with those of isolated sulfur oxidizers in the classes Betaproteobacteria and Gammaproteobacteria. Although the combinations of these genes in the respective genomes are diverse, typical combinations corresponding to three types of core sulfur oxidation pathways were identified. Each pathway involves one of three specific sets of proteins, SoxCD, DsrABEFHCMKJOP, and HdrCBAHypHdrCB. All three core pathways contain the SoxXYZAB proteins, and a cytoplasmic sulfite oxidase encoded by soeABC is a conserved component in the core pathways lacking SoxCD. Phylogenetically close organisms share same core sulfur oxidation pathway, but a notable exception was observed in the family ‘Sulfuricellaceae’. In this family, some strains have either core pathway involving DsrABEFHCMKJOP or HdrCBAHypHdrCB, while others have both pathways. A proteomics analysis showed that proteins constituting the core pathways were produced at high levels. While hypothesized function of HdrCBAHypHdrCB is similar to that of Dsr system, both sets of proteins were detected with high relative abundances in the proteome of a strain possessing genes for these proteins. In addition to the genes for sulfur oxidation, those for arsenic metabolism were searched for in the sequenced genomes. As a result, two strains belonging to the families Thiobacillaceae and Sterolibacteriaceae were observed to harbor genes encoding ArxAB, a type of arsenite oxidase that has been identified in a limited number of bacteria. These findings were made with the newly obtained genomes, including those from 6 genera from which no genome sequence of an isolated organism was previously available. These genomes will serve as valuable references to interpret nucleotide sequences.

Hypoglossal nerve palsy (HNP) is a potential cause of dysphagia. A 66-year-old man presented to our hospital with dysphagia and neck pain. One year prior to his first visit, he had been diagnosed with upper cervical tuberculosis and had undergone posterior C1-2 fixation. The physical examination led to the diagnosis of dysphagia with HNP, and he had severe weight loss. Radiographic examination revealed that the O-C kyphosis had been exacerbated and that the deformity was likely the primary cause of HNP. To restore the swallowing function, O-C fusion surgery was performed. Postoperatively, the patient showed immediate improvement of dysphagia with gradual recovery of hypoglossal nerve function. In the last follow-up evaluation, swallowing function was confirmed with no signs of HNP. Our results indicate that HNP could be more prevalent in cases with severe cervical kyphosis, being underdiagnosed due to the more apparent signs of the oropharyngeal narrowing.

Background: This study aimed to evaluate and identify the specific CT findings by focusing on abnormalities in the main pancreatic duct (MPD) and pancreatic parenchyma in patients with small pancreatic cancer (PC) including carcinoma in situ (CIS). Methods: Nine CT findings indicating abnormalities of MPD and pancreatic parenchyma were selected as candidate findings for the presence of small PC ≤ 10 mm. The proportions of patients positive for each finding were compared between small PC and benign MPD stenosis groups. Interobserver agreement between two independent image reviewers was evaluated using kappa statistics. Results: The final analysis included 24 patients with small PC (including 11 CIS patients) and 28 patients with benign MPD stenosis. The proportion of patients exhibiting partial pancreatic parenchymal atrophy (PPA) corresponding to the distribution of MPD stenosis (45.8% vs. 7.1%, p < 0.01), upstream PPA arising from the site of MPD stenosis (33.3% vs. 3.6%, p = 0.01), and MPD abrupt stenosis (45.8% vs. 14.3%, p = 0.03) was significantly higher in the small PC group than in the benign MPD stenosis group. Conclusions: The presence of partial PPA, upstream PPA, and MPD abrupt stenosis on a CT image was highly suggestive of the presence of small PCs including CIS.

Cap polyposis is a rare gastrointestinal disease characterized by multiple inflammatory polyps located between the distal colon and the rectum. Despite the lack of clarity regarding its pathogenesis, mucosal prolapse, chronic inflammatory responses, and Helicobacter pylori infection are considered key contributors to the development of this disease entity. Although it is now generally accepted that dysbiosis of gut microbiota is associated with intestinal and extra-intestinal diseases, alterations of intestinal microbiota have been poorly defined in cap polyposis. Here, we report a patient with H. pylori-negative cap polyposis who was successfully treated with antibiotics and exhibited dramatic alterations in intestinal microbiota composition after antibiotic treatment. The patient was treated with oral administration of ampicillin and metronidazole and showed regression of cap polyposis 6 months after antibiotic treatment. Fecal microbiota analysis using the next-generation sequencing technology revealed a significant alteration in the intestinal microbiota composition following antibiotic treatment—a marked reduction of Blautia, Dorea, and Sutterella was observed concomitant with a marked increase in Fusobacterium. These data suggest that cap polyposis may originate from dysbiosis and that microbiome-targeted therapy may be useful in this disorder.

Our case is a first report of autoimmune pancreatitis with multiple masses within the pancreas which was pathologically diagnosed by endoscopic ultrasound-guided fine needle aspiration and treated by steroid. The masses disappeared by steroid therapy. Our case is informative to know that autoimmune pancreatitis sometimes exhibits multiple masses within the pancreas and to diagnose it without unnecessary surgery.

Planktonic sulfur oxidizers are important constituents of ecosystems in stratified water bodies, and contribute to sulfide detoxification. In contrast to marine environments, taxonomic identities of major planktonic sulfur oxidizers in freshwater lakes still remain largely unknown. Bacterioplankton community structure was analyzed in a stratified freshwater lake, Lake Mizugaki in Japan. In the clone libraries of 16S rRNA gene, clones very closely related to a sulfur oxidizer isolated from this lake, Sulfuritalea hydrogenivorans, were detected in deep anoxic water, and occupied up to 12.5% in each library of different water depth. Assemblages of planktonic sulfur oxidizers were specifically analyzed by constructing clone libraries of genes involved in sulfur oxidation, aprA, dsrA, soxB and sqr. In the libraries, clones related to betaproteobacteria were detected with high frequencies, including the close relatives of Sulfuritalea hydrogenivorans.

Infection of the stomach with Helicobacter pylori is an important risk factor for gastritis, peptic ulcer, and gastric carcinoma. Although it has been well established that persistent colonization by H. pylori is associated with adaptive Th1 responses, the innate immune responses leading to these Th1 responses are poorly defined. Recent studies have shown that the activation of nucleotide-binding oligomerization domain 1 (NOD1) in gastric epithelial cells plays an important role in innate immune responses against H. pylori. The detection of H. pylori-derived ligands by cytosolic NOD1 induces several host defense factors, including antimicrobial peptides, cytokines, and chemokines. In this paper, we review the molecular mechanisms by which NOD1 contributes to mucosal host defense against H. pylori infection of the stomach.

IgA vasculitis (Henoch-Schönlein purpura) affects various organs, including the skin, gastrointestinal (GI) tract, joints and kidneys. Its clinical course typically consists of two phases: initial appearance of purpura and delayed onset of arthralgia, GI symptoms and haematuria. We report the case of an adult patient with IgA vasculitis of the small bowel, without skin involvement, complicated by cytomegalovirus (CMV) enteritis following prednisolone administration. Single-balloon enteroscopy revealed mucosal oedema, redness, erosions and transverse ulcers of the duodenum and jejunum. Jejunal biopsy specimens showed IgA deposition in the capillary walls. CMV reactivation was confirmed by PCR and immunostaining using jejunal biopsy specimens. This case report strongly suggests that adult patients with IgA vasculitis can present with isolated GI involvement, without characteristic skin purpura. Furthermore, CMV reactivation needs to be considered in patients with IgA vasculitis showing poor response to glucocorticoids. [ABSTRACT FROM AUTHOR]

IgG4-related disease (IgG4-RD) is a newly defined multi-organ disease proposed by Japanese physicians. IgG4-RD is characterized by elevated serum levels of IgG4 and massive infiltration of IgG4-expressing plasma cells in the affected organs. Recent studies have shown that abnormal adaptive immune responses mediated by T helper type 2 cells, regulatory T cells, follicular helper T cells, cytotoxic CD4þ T cells, and plasmablasts are involved in IgG4-RD immunopathogenesis. In addition to adaptive immune responses, innate immune responses play pathogenic roles in IgG4-RD. Plasmacytoid dendritic cells (pDCs), M2 macrophages, and basophils are activated to produce various kinds of cytokines in IgG4-RD. Recent studies highlight the importance of type I IFN and IL-33 produced by pDCs in IgG4-RD immunopathogenesis. [ABSTRACT FROM AUTHOR]

Myelodysplastic syndrome [MDS] is a clonal disorder of bone marrow [BM] cells, caused by acquired chromosomal abnormalities and gene mutations. Pro-inflammatory antigen-presenting cells [APCs] originating from BM cells bearing chromosomal abnormalities and gene mutations can cause immune-mediated disorders including inflammatory bowel disease [IBD]. Here, we report the first case with MDS-associated IBD that was successfully treated with the DNA methyltransferase inhibitor, azacitidine [AZA]. A 75-year-old man with a 5-year history of MDS was admitted for examination of diarrhoea and high fever. Blood examination revealed pancytopenia and a marked elevation of C-reactive protein. Colonoscopy revealed multiple round ulcers from the terminal ileum to the sigmoid colon. Pathological examination of the endoscopic biopsy specimens showed destruction of crypt architecture and infiltration of CD3+ T cells and CD68+ macrophages. Surprisingly, administration of AZA, which has been approved for the treatment of high-risk MDS, improved the symptoms, and the multiple round ulcers disappeared. AZA treatment markedly decreased the expressions of tumour necrosis factor-a, interleukin-12 (IL-12)/23p40 and IL-17 in colonic biopsy samples, as assessed by quantitative reverse transcription polymerase chain reaction. In contrast, AZA treatment did not change the expression of forkhead box P3, a master regulator of regulatory T cells. These data suggest that AZA treatment led to complete remission in MDS-associated IBD through suppression of pro-inflammatory cytokine responses. [ABSTRACT FROM AUTHOR]

Background: Transarterial chemoembolization (TACE) is recommended for patients with hepatocellular carcinoma (HCC) in Barcelona Clinic Liver Cancer (BCLC) stage B. However, because of the heterogeneity of HCC in BCLC stage B; various subclassification systems have been proposed to predict the prognosis of patients. Previously, we proposed the Kinki criteria for precise classification of HCC cases in BCLC stage B. In this study, we compared the time to TACE refractoriness in HCC patients with Kinki criteria substages B1 and B2-HCC. Summary: Between January 2006 and December 2013, 592 HCC patients (substage B1, n = 118; substage B2, n = 170) underwent TACE. Time to progression under TACE treatment was defined as the time to untreatable progression (TTUP). TTUP and changes in liver function were analyzed in patients with substages B1 and B2-HCC. The median TTUP was 25.7 months (95% CI 19.3-37.3) and 16.4 months (95% CI 13.1-20.2) in patients with substage B1-HCC and substage B2-HCC, respectively ( p = 0.0050). In patients with substage B2-HCC, median Child-Pugh scores after the first TACE session was significantly different from those after third and fifth TACE sessions (first-third, p = 0.0020; first-fifth, p = 0.0008). Key Message: TACE refractoriness occurred earlier in patients with substage B2-HCC than those with substage B1-HCC; deterioration of liver function with repeated TACE was more obvious in HCC cases with stage-B1 tumor. Shorter TTUP and impaired liver function due to repeated TACE could be responsible for the shorter survival in patients with substage B2-HCC. [ABSTRACT FROM AUTHOR]

Background: Tumors classified based on the Barcelona Clinic Liver Cancer (BCLC) stage B hepatocellular carcinoma (HCC) are heterogeneous in nature. Previously, the Kinki criterion was proposed for a more precise subclassification of tumors in BCLC-stage B. However, tumors in sub-stage B2 include various size and number of HCCs even with the Kinki criteria, which could lead to heterogeneity for overall survival (OS). In this study, we assessed how the size and number of tumors affect the OS and time to progression (TTP) in patients with Kinki criteria stage B2 tumors and treated with transarterial chemoembolization (TACE). Methods: Of 906 HCC patients treated with TACE at Kindai University Hospital, 236 patients with HCC considered as Kinki criteria stage B2 were examined. They were classified into the following 4 groups according to the maximum tumor diameter and number of tumors: B2a group, tumor size ≤6 cm and total number of tumors ≤6; B2b group, size ≤6 cm and number >6; B2c group, size >6 cm and number ≤6; and B2d group, size >6 cm and number >6. The OS and TTP of patients in each group were compared. Results: There were 131 patients (55.5%) in the B2a group, 58 (24.6%) in the B2b group, 41 (17.4%) in the B2c group, and 6 (0.03%) in the B2d group. Comparison of the survivals revealed that the median OS was 2.8 years (95% CI 2.0-3.5) in the B2a group, 2.8 years (95% CI 2.0-3.3) in the B2b group, 1.9 years (95% CI 0.8-4.0) in the B2c group, and 2.3 years (95% CI 1.2-ND [no data]) in the B2d group, respectively (p = 0.896). The median TTP in B2a, B2b, B2c, and B2d sub-substage HCC were13.2, 12.1, 13.8, and 11.5 months, respectively (p = 0.047). The median TTP in B2a + B2c sub-substage patients was longer than that in B2b + B2d sub-substage HCC patients (14.0 months and 10.4 months; p = 0.002). Conclusion: No significant differences were observed in the OS among HCC patients subclassified based on the maximum tumor diameter and tumor number in Kinki criteria stage B2. Consequently, Kinki criteria stage B2 HCC is a homogeneous subgroup in terms of OS prediction. However, shorter TTP in B2b+B2c sub-substage HCC patients than that in B2a + B2c sub-substage HCC patients suggests that different treatment strategy, such as systemic therapy with targeted agents instead of TACE, may be suitable to preserve the liver function. [ABSTRACT FROM AUTHOR]

Background and Aims: Direct-acting antivirals (DAAs) dramatically improve the sustained virological response (SVR) of chronic hepatitis C (CHC) patients. However, continuous liver damage after SVR may be a risk of hepatocellular carcinoma (HCC). We clarified pretreatment characteristics related to sustained liver damage after SVR. Methods: A total of 286 CHC patients were treated with an interferon-free DAA regimen. Among them, 250 patients achieved SVR for 12 weeks after the end of treatment (SVR12); these individuals were classified based on α-fetoprotein (AFP) and alanine transaminase (ALT) levels posttreatment. Baseline characteristics significantly associated with AFP >5 ng/mL and ALT level ≥ 20 IU/L after SVR were clarified using multivariate analyses. Results: Among the pretreatment factors examined, serum AFP values and the presence of fatty liver (FL) were significantly associated with abnormal AFP ( p < 0.0001) and ALT levels 12 weeks after SVR12 (SVR24; p = 0.0109). For 126 patients who showed an increase in baseline AFP level, FL, fibrosis-4 (FIB-4) index, and albumin levels before treatment were related to abnormal AFP at SVR24 ( p = 0.0005, 0.0232, and 0.0400 for FL, FIB-4 index, and albumin, respectively). Similarly, for 150 patients with abnormal baseline ALT levels, FL was associated with an ALT level ≥ 30 IU/L after SVR ( p = 0.0430). Conclusions: High FIB-4 index, low albumin level, and FL before DAA treatment were associated with a risk of sustained liver damage with AFP and ALT elevation after SVR; patients with these factors should be carefully monitored for emergence of HCC. [ABSTRACT FROM AUTHOR]

Objective: It is a generally accepted fact that eradication of hepatitis virus C inhibits the subsequent development of hepatocellular carcinoma (HCC). On the contrary, a significant population of patients developed HCC despite sustained virological responses (SVRs) to interferon (IFN) therapy. Methods: A total of 415 patients with chronic hepatitis C, who were treated at our hospital between 2004 and 2014, were enrolled for this study. We examined the risk factors for HCC development after IFN therapy. Results: After analyzing various clinical parameters, it was concluded that a serum albumin (ALB) level <4.0 g/dL and the presence or absence of SVR achievement were risk factors for the development of HCC. When analyzing pre- and posttreatment factors, only a serum ALB level <4.0 g/dL was considered a significant risk factor. The presence or absence of liver fibrosis progression was not identified as a risk factor. Conclusions: In patients with a serum ALB level <4.0 g/dL before IFN therapy, hepatic carcinogenesis after SVR achievement need to be considered. Furthermore, the serum ALB level may be more useful than the degree of fibrosis for the prediction of HCC after SVR in chronic hepatitis C. [ABSTRACT FROM AUTHOR]

In previous studies, we found that human IgG4-related autoimmune pancreatitis (AIP) and murine AIP are driven by activation of plasmacytoid dendritic cells (pDCs) producing IFN-α. In the present studies we examined additional roles of pDC-related mechanisms in AIP pathogenesis, particularly those responsible for induction of fibrosis. We found that in murine AIP (MRL/Mp mice treated with polyinosinic-polycytidylic acid) not only the pancreatic infiltration of immune cells but also the development of fibrosis were markedly reduced by the depletion of pDCs or blockade of type I IFN signaling; moreover, such treatment was accompanied by a marked reduction of pancreatic expression of IL-33. Conversely, polyinosinic-polycytidylic acid-induced inflamed pancreatic tissue in murine AIP exhibited increased expression of type I IFNs and IL-33 (and downstream IL-33 cytokines such as IL-13 and TGF-β1). pDCs stimulated by type I IFN were the source of the IL-33 because purified populations of these cells isolated from the inflamed pancreas produced a large amount of IL-33 upon activation by TLR9 ligands, and such production was abrogated by the neutralization of type I IFN. The role of IL-33 in murine AIP pathogenesis was surprisingly important because blockade of IL-33 signaling by anti-ST2 Ab attenuated both pancreatic inflammation and accompanying fibrosis. Finally, whereas patients with both conventional pancreatitis and IgG4-related AIP exhibited increased numbers of acinar cells expressing IL-33, only the latter also exhibited pDCs producing this cytokine. These data thus suggest that pDCs producing IFN-&3945; and IL-33 play a pivotal role in the chronic fibro-inflammatory responses underlying murine AIP and human IgG4-related AIP. [ABSTRACT FROM AUTHOR]