Impact of clinical characteristics of colonic diverticular bleeding in extremely elderly patients treated with direct oral anti-coagulant drugs: a retrospective multi-center study.

Since there were no available data about colonic diverticular bleeding in extremely elderly patients (>80 years old) treated with direct oral anticoagulants (DOACs), we tried to determine clinical characteristics in those with colonic diverticular bleeding taking DOACs and to compare clinical outcomes of those in DOAC-treated to those in warfarin-treated . We enrolled DOAC-treated (n = 20) and warfarin-treated (n = 23) extremely elderly patients with diverticular bleeding diagnosed by colonoscopy. We performed a retrospective review of patients' medical charts and endoscopic findings. We classified colonic diverticular bleeding based on endoscopic features due to modified previous study following three groups, type A (active bleeding), type B (non-active bleeding) and type C (bleeding suspected). Clinical outcomes such as number of recurrent bleeding, thrombotic events and mortality were estimated. There were no differences in endoscopical features and clinical characteristics between patients treated with DOAC and warfarin therapy. However, the number of recurrent bleeding, frequency of required blood transfusions and units of blood transfusion in warfarin-treated patients were significantly higher (p<0.05) compared to those in DOAC-treated groups. In addition, mortality and thrombotic events did not differ between DOAC- and warfarin-treated patients. Clinical outcomes suggest that DOACs can be recommended for extremely elderly patients with colonic diverticular disease.

Linked Color Imaging and the Kyoto Classification of Gastritis: Evaluation of Visibility and Inter-Rater Reliability.

BACKGROUND/AIMS: To compare white light imaging (WLI) with linked color imaging (LCI) and blue LASER imaging (BLI) in endoscopic findings of Helicobacter pylori presently infected, previously infected, and uninfected gastric mucosae for visibility and inter-rater reliability. METHODS: WLI, LCI and BLI bright mode (BLI-bright) were used to obtain 1,092 endoscopic images from 261 patients according to the Kyoto Classification of Gastritis. Images were evaluated retrospectively by 10 experts and 10 trainee endoscopists and included diffuse redness, spotty redness, map-like redness, patchy redness, red streaks, intestinal metaplasia, and an atrophic border (52 cases for each finding, respectively). Physicians assessed visibility as follows: 5 (improved), 4 (somewhat improved), 3 (equivalent), 2 (somewhat decreased), and 1 (decreased). Visibility was assessed from totaled scores. The inter-rater reliability (intraclass correlation coefficient) was also evaluated. RESULTS: Compared with WLI, all endoscopists reported improved visibility with LCI: 55.8% for diffuse redness; LCI: 38.5% for spotty redness; LCI: 57.7% for map-like redness; LCI: 40.4% for patchy redness; LCI: 53.8% for red streaks; LCI: 42.3% and BLI-bright: 80.8% for intestinal metaplasia; LCI: 46.2% for an atrophic border. For all endoscopists, the inter-rater reliabilities of LCI compared to WLI were 0.73-0.87. CONCLUSION: The visibility of each endoscopic finding was improved by LCI while that of intestinal metaplasia was improved by BLI-bright.

Regulatory T-cell dysfunction induces autoantibodies to bullous pemphigoid antigens in mice and human subjects.

BACKGROUND: Regulatory T (Treg) cells play a crucial role in peripheral immune tolerance in multiple organs, including the skin. Thus far, the effect of peripheral immune tolerance failure on autoantibody-related autoimmune reactions to the skin is unclear. OBJECTIVE: We sought to elucidate the target autoantigens in the skin under the condition of Treg cell dysfunction caused by forkhead box P3 (Foxp3) gene mutations in scurfy mice and patients with immunodysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome. METHODS: Sera and skin from scurfy mice and sera from patients with IPEX syndrome were analyzed to detect target autoantigens by using immunofluorescence studies, ELISAs, and immunoblotting. The pathogenicity of scurfy IgG was examined by using a passive transfer experiment. CD4+ T cells from scurfy mice were transferred to immunodeficient mice to examine their pathogenicity. Signal transducer and activator of transcription 6 (Stat6)-/- scurfy mice were analyzed to further clarify the molecular pathway of autoantibody production. Follicular helper T-cell counts are measured in Stat6-/- scurfy mice and scurfy mice. RESULTS: Scurfy mice spontaneously generated IgG autoantibodies to the dermal-epidermal junction, which had been class-switched from IgM within 12 days after birth. The target autoantigens were murine BP230 and type XVII collagen (COL17). The scurfy polyclonal autoantibodies did not induce skin fragility in neonatal mice. Autoantibody production was induced by CD4+ T cells from scurfy mice and was ameliorated by Stat6 gene knockout in association with a decrease of follicular helper T cells. We also identified autoantibodies to COL17 and BP230 in patients with IPEX syndrome and found an association between production of autoantibodies to COL17 and an eczematous skin phenotype. CONCLUSIONS: Dysregulation of Treg cells generates autoantibodies to COL17 and BP230 in vivo.

Improved Visibility of Barrett's Esophagus with Linked Color Imaging: Inter- and Intra-Rater Reliability and Quantitative Analysis.

BACKGROUND/AIMS: To evaluate the usefulness of linked color imaging (LCI) and blue LASER imaging (BLI) in Barrett's esophagus (BE) compared with white light imaging (WLI). METHODS: Five expert and trainee endoscopists compared WLI, LCI, and BLI images obtained from 63 patients with short-segment BE. Physicians assessed visibility as follows: 5 (improved), 4 (somewhat improved), 3 (equivalent), 2 (somewhat decreased), and one (decreased). Scores were evaluated to assess visibility. The inter- and intra-rater reliability (intra-class correlation coefficient) of image assessments were also evaluated. Images were objectively evaluated based on L* a* b* color values and color differences (ΔE*) in a CIELAB color space system. RESULTS: Improved visibility compared with WLI was achieved for LCI: 44.4%, BLI: 0% for all endoscopists; LCI: 55.6%, BLI: 1.6% for trainees; and LCI: 47.6%, BLI: 0% for experts. The visibility score of trainees compared with experts was significantly higher for LCI (p = 0.02). Intra- and inter-rater reliability ratings for LCI compared with WLI were "moderate" for trainees, and "moderate-substantial" for experts. The ΔE* revealed statistically significant differences between WLI and LCI. CONCLUSION: LCI improved the visibility of short-segment BE compared with WLI, especially for trainees, when evaluated both subjectively and objectively.

Loss of interaction between plectin and type XVII collagen results in epidermolysis bullosa simplex.

Plectin is a linker protein that interacts with intermediate filaments and ß4 integrin in hemidesmosomes of the epidermal basement membrane zone (BMZ). Type XVII collagen (COL17) has been suggested as another candidate plectin binding partner in hemidesmosomes. Here, we demonstrate that plectin-COL17 binding helps to maintain epidermal BMZ organization. We identified an epidermolysis bullosa (EB) simplex patient as having markedly diminished expression of plectin and COL17 in skin. The patient is compound heterozygous for sequence variants in the plectin gene (PLEC); one is a truncation and the other is a small in-frame deletion sequence variant. The in-frame deletion is located in the putative COL17-binding domain of plectin and abolishes the plectin-COL17 interaction in vitro. These results imply that disrupted interaction between plectin and COL17 is involved in the development of EB. Our study suggests that protein-protein binding defects may underlie EB in patients with unidentified disease-causing sequence variants.

Autoantibodies of non-inflammatory bullous pemphigoid hardly deplete type XVII collagen of keratinocytes.

Type XVII collagen (COL17) and the non-collagenous 16A (NC16A) domain is regarded as the major pathogenic domains for bullous pemphigoid (BP). Some patients with BP have autoantibodies against parts of COL17 outside the NC16A domain (hereinafter the non-NC16A domain) and show less inflammatory manifestations. There were no significant differences in titres and IgG subclasses between NC16A-BP and non-NC16A-BP as determined by indirect immunofluorescent microscopy. The neutrophil activation capacities determined by ROS release did not differ between NC16A-BP and non-NC16A-BP. However, NC16A-BP IgG depleted COL17 in a dose-dependent manner. Treatment with NC16A-BP IgG, but not with non-NC16A-BP IgG, significantly decreased the adhesion strength. We speculate that the differences in clinical severity between NC16A-BP and non-NC16A-BP relate to the degree of COL17 depletion.

A Randomized, Double-Blind, Pilot Study of the Effect of Famotidine on Acotiamide Treatment for Functional Dyspepsia.

BACKGROUND/AIMS: Acotiamide, a prokinetic drug, is used to treat functional dyspepsia (FD), especially postprandial distress syndrome (PDS). However, a treatment for FD patients with PDS and/or epigastric pain syndrome (EPS) has not been established. We investigated the efficacy of famotidine in combination with acotiamide for FD. METHODS: Fifty blindly randomized FD patients received placebo with acotiamide, or famotidine with acotiamide, for 4 weeks. Treatment efficacy was assessed by overall treatment effects (OTE), total, PDS and EPS symptom scores, and impairment of quality of life (QOL). RESULTS: After OTE assessment, patients who felt affected by treatment comprised 40.9 and 57.9% of famotidine and placebo groups, respectively, after 4 weeks' treatment, with no significant difference between groups. A significant decrease was seen in total, PDS, and EPS symptom scores, and in QOL impairment, after 4 weeks' treatment compared with pretreatment scores for famotidine and placebo groups, but was not observed between groups. The proportion of patients showing a ≥50% decrease in EPS symptom scores was greater in the famotidine than that in the placebo group for every observation point, with the greatest difference observed after 2 weeks' treatment. CONCLUSION: The effectiveness of famotidine and acotiamide combination therapy in FD was similar to the effectiveness of acotiamide therapy alone.

Macropinocytosis of type XVII collagen induced by bullous pemphigoid IgG is regulated via protein kinase C.

Macropinocytosis is an endocytic pathway that is involved in the nonselective fluid uptake of extracellular fluid. Bullous pemphigoid (BP) is an autoimmune subepidermal blistering disease associated with autoantibodies to type XVII collagen (COL17), which is a component of hemidesmosome. When keratinocytes are treated with BP-IgG, COL17 internalizes into cells by way of the macropinocytosis. We investigated the mechanism of COL17 macropinocytosis using DJM-1 cells, a cutaneous squamous cell carcinoma cell line. First, non-hemidesmosomal COL17 was preferentially depleted by stimulation with the BP-IgG in the DJM-1 cells. To investigate the signaling involved in COL17-macropinocytosis, the inhibition of small GTPase family members Rac1 and Cdc42 was found to strongly repress COL17 internalization; in addition, the Rho inhibitor also partially blocked that internalization, suggesting these small GTPases are involved in signaling to mediate COL17-macropinocytosis. Western blotting using Phostag-SDS-PAGE demonstrated high levels of COL17 phosphorylation in DJM-1 cells under steady-state condition. Treatment with BP-IgG increased the intracellular calcium level within a minute, and induced the overabundant phosphorylation of COL17. The overabundant phosphorylation of COL17 was suppressed by a protein kinase C (PKC) inhibitor. In addition, PKC inhibitor repressed COL17 endocytosis using cell culture and organ culture systems. Finally, the depletion of COL17 was not observed in the HEK293 cells transfected COL17 without intracellular domain. These results suggest that COL17 internalization induced by BP-IgG may be mediated by a PKC pathway. In summary, BP-IgG initially binds to COL17 distributed on the plasma membrane, and COL17 may be internalized by means of a macropinocytic pathway related to the phosphorylation of the intracellular domain by PKC.

Context-Dependent Regulation of Collagen XVII Ectodomain Shedding in Skin.

Pemphigoid is a common autoimmune blistering disorder in which autoantibodies target transmembrane collagen XVII (COL17), a component of hemidesmosomes in basal keratinocytes. The ectodomain of COL17 can be cleaved from the cell surface within the juxtamembranous extracellular NC16A domain, and, interestingly, certain autoantibodies of pemphigoid patients preferentially react with the shed ectodomain. These findings suggest that COL17 ectodomain shedding generates neoepitopes on the shed form; however, the regulatory mechanism of the shedding in in vivo skin and the pathogenicity of the neoepitope-targeting antibodies still are uncertain. To address these issues, we produced rabbit antibodies specifically reacting with N-terminal cleavage sites of the shed COL17 ectodomain. The antibodies showed that certain amounts of the human COL17 ectodomain are cleaved physiologically at Gln(525) in in vivo skin. In contrast, migrating human keratinocytes cleave COL17 at Leu(524) but not at Gln(525). The passive transfer of antibodies reacting with an N-terminal cleavage site of the mouse COL17 ectodomain into neonatal wild-type mice failed to induce blister formation, even though the antibodies bound to the dermal-epidermal junctions, indicating that cleavage site-specific antibodies have reduced or absent pathogenicity for blister formation. This study shows the ectodomain shedding of COL17 to be a physiological event in in vivo human skin that probably generates nonpathologic epitopes on the cleavage sites.

Bullous pemphigoid autoantibodies directly induce blister formation without complement activation.

Complement activation and subsequent recruitment of inflammatory cells at the dermal/epidermal junction are thought to be essential for blister formation in bullous pemphigoid (BP), an autoimmune blistering disease induced by autoantibodies against type XVII collagen (COL17); however, this theory does not fully explain the pathological features of BP. Recently, the involvement of complement-independent pathways has been proposed. To directly address the question of the necessity of the complement activation in blister formation, we generated C3-deficient COL17-humanized mice. First, we show that passive transfer of autoantibodies from BP patients induced blister formation in neonatal C3-deficient COL17-humanized mice without complement activation. By using newly generated human and murine mAbs against the pathogenic noncollagenous 16A domain of COL17 with high (human IgG1, murine IgG2), low (murine IgG1), or no (human IgG4) complement activation abilities, we demonstrate that the deposition of Abs, and not complements, is relevant to the induction of blister formation in neonatal and adult mice. Notably, passive transfer of BP autoantibodies reduced the amount of COL17 in lesional mice skin, as observed in cultured normal human keratinocytes treated with the same Abs. Moreover, the COL17 depletion was associated with a ubiquitin/proteasome pathway. In conclusion, the COL17 depletion induced by BP autoantibodies, and not complement activation, is essential for the blister formation under our experimental system.

Frequent occurrence of fever in patients who have undergone endoscopic submucosal dissection for colorectal tumor, but bacteremia is not a significant cause.

BACKGROUND: We examined the incidence of and factors associated with fever, as well as the frequency of bacteremia, in patients who had undergone endoscopic submucosal dissection (ESD) for colorectal tumor. METHOD: A total of 199 patients (120 male and 79 female) were included. The patients were classified into two groups based on the body temperature on the day after ESD treatment: group A, body temperature <37 °C; and group B, body temperature ≥37 °C. The following factors were analyzed to determine their potential association with post-ESD fever: gender, age, tumor size, form, location, and presence or absence of intraoperative perforation. In addition, blood samples from 50 patients were obtained for blood culture and 16S rRNA gene analysis by polymerase chain reaction. RESULTS: Group A included 106 patients (70 male and 36 female), with a median age of 63 years. Group B included 93 patients (50 male and 43 female), with a median age of 70 years. The incidence of post-ESD fever in the entire cohort was 46.7%. Univariate analysis based on comparison between groups A and B showed that the following factors were significantly associated with post-ESD fever: age [mean ± standard deviation (SD)], 64.5 ± 9.2 versus 68.5 ± 10.8 years, P = 0.006; and tumor size (mean ± SD) 30.6 ± 10.8 versus 39.1 ± 16.6 mm, P < 0.001. Logistic regression analysis for post-ESD fever also found that age {odds ratio 1.04 (95% CI [1.01-1.07], P = 0.009)} and lesion size {odds ratio 1.05 (95% CI [1.03-1.08], P = 0.0002)} were closely associated with post-ESD fever. Of the 50 patients who had blood samples cultured and 16S rRNA gene analyzed, bacteria in blood culture and the 16S rRNA gene were not detectable in any of the samples from the 50 patients. CONCLUSIONS: This study indicated that older patients and patients with large tumors were more likely to develop post-ESD fever, but there was a low probability that bacteremia was the cause of fever.

Phylogeography and genetic diversity of the Japanese mud shrimp Upogebiamajor (Crustacea, Decapoda, Upogebiidae): Natural or anthropogenic dispersal?

Upogebiamajor (De Haan, 1841) is known for forming huge burrows in sandy, intertidal areas that can extend to depths of over 2 m. Despite its widespread distribution in East Asia and Russia, the genetic relatedness of its regional populations remains uncertain, likely owing to difficulties in specimen collection. Therefore, to appraise the phylogeographic patterns, genetic diversity, and morphological variety of U.major, the mitochondrial DNA of specimens collected from Japan, Korea and China were subjected to molecular phylogenetic analyses of COI genes, alongside morphological assessment. As a result, we discovered four principal groups; of these, Group 1 consisted predominantly of Japanese specimens, while Groups 3 and 4 were interpreted as having originated from the continent. Group 2 exhibited genetic segregation from both continental and Japanese descent. Group 1 mostly comprising Japanese specimens implies that the planktonic larvae of U.major were disseminated north and south by ocean currents encompassing the Japanese archipelago. In contrast, individuals probably originating from the continent were discovered in Lake Notoro, Hokkaido and Matsukawa-ura, Fukushima in northeastern Japan, indicating possible introduction from the continent through ocean currents or unintentional introduction with other organisms imported. Additionally, one of the specimens collected from Matsukawa-ura exhibited significant genetic and morphological differences from other specimens, suggesting the possibility of being a subspecies. The outcomes of this study not only offer valuable insights into the origins of distribution of U.major but also introduce a novel challenge of assessing the coexistence of two routes: natural and anthropogenic dispersion.