Identification of a novel histone H2A mono-ubiquitination-inhibiting cell-active small molecule.

Histone H2A mono-ubiquitination plays important roles in epigenetic gene expression and is also involved in tumorigenesis. Small molecules controlling H2A ubiquitination are of interest as potential chemical tools and anticancer drugs. To identify novel small molecule inhibitors of H2A ubiquitination, we synthesized and evaluated several compounds designed based on PRT4165 (1), which is a reported histone ubiquitin ligase RING1A inhibitor. We found that compound 11b strongly inhibited the viability and reduced histone H2A mono-ubiquitination in human osteosarcoma U2OS cells. Therefore, compound 11b is a promising lead compound for the development of H2A histone ubiquitination-inhibiting small molecules.

Structural optimization of a lysine demethylase 5 inhibitor for improvement of its cellular activity.

Lysine demethylase 5 (KDM5) subfamily proteins are important in epigenetic gene regulation. They are involved in the growth and drug resistance of cancer cells. Therefore, KDM5s are potential cancer therapeutic targets, and their inhibitors hold promise as anti-cancer drugs. Several KDM5 inhibitors, including KDM5-C49 (2a), have exhibited potent KDM5-inhibitory activities in in vitro enzyme assays. However, they do not show enough cellular activity despite being converted to their prodrugs. We hypothesized that their poor lipophilicity should prevent them from sufficiently penetrating the cell membrane, and introducing more lipophilic groups should improve cellular activities. In this study, we investigated 2a and KDM5-C70 (3a), a prodrug of 2a, and attempted to improve its cellular activity by replacing the N,N-dimethyl amino group of 3a with more lipophilic groups. N-Butyl, N-methyl amino compound 2e exhibited potent and selective KDM5-inhibitory activity equal to that of 2a. Furthermore, the cell membrane permeability of 3e, an ethyl ester prodrug of 2e, was six times higher than that of 3a in a parallel artificial membrane permeation assay. In addition, western blot analysis indicated that treating human lung cancer A549 cells with 3e increased histone methylation levels more strongly than that with 3a. Thus, we identified compound 3e as a more cell-active KDM5 inhibitor that has sufficient cell membrane permeability.

Design, synthesis, and biological evaluation of phenylcyclopropylamine-entinostat conjugates that selectively target cancer cells.

Small molecule-based selective cancer cell-targeting can be a desirable anticancer therapeutic strategy. Aiming to discover such small molecules, we previously developed phenylcyclopropylamine (PCPA)-drug conjugates (PDCs) that selectively release anticancer agents in cancer cells where lysine-specific demethylase 1 (LSD1) is overexpressed. In this work, we designed PCPA-entinostat conjugates for selective cancer cell targeting. PCPA-entinostat conjugate 12 with a 4-oxybenzyl group linker released entinostat in the presence of LSD1 in in vitro assays and selectively inhibited the growth of cancer cells in preference to normal cells, suggesting the potential of PCPA-entinostat conjugates as novel anticancer drug delivery small molecules.

Safety of skipping the tract dilation step for EUS-guided biliary drainage in patients with unresectable malignant biliary obstruction (with video).

BACKGROUND: Thin delivery system stents can be inserted directly without the need for a tract dilation step and are expected to reduce bile leakage during endoscopic ultrasound-guided biliary drainage (EUS-BD). The present study retrospectively compared the safety and efficacy of EUS-BD using a thin metal stent (< 7.5 Fr) with those of EUS-BD using a conventional stent (≥ 7.5 Fr). METHODS: The present study enrolled 112 patients who underwent EUS-BD using metal stents for unresectable malignant biliary obstruction between April 2016 and July 2022. The primary endpoint was the rate of adverse events (AEs). The secondary endpoints were clinical success rate, procedure time, procedure success rate in the absence of the tract dilation step, recurrent biliary obstruction rate, time to biliary obstruction, and overall survival. Risk factors associated with early AEs were also evaluated. RESULTS: The rate of early AEs was significantly lower (12% vs. 35%, P = 0.013) and the procedure success without the tract dilation step was significantly higher (82% vs. 33%, P < 0.001) in the thin than in the conventional delivery system stent group. None of the other secondary endpoints differed significantly between the two groups. Multivariate analysis showed that employing the tract dilation step during EUS-BD was a significant independent risk factor for early AEs (skipping vs. employing; HR, 9.66; 95% CI, 1.13-83.0, P = 0.028). CONCLUSION: Employing the tract dilation step during EUS-BD was a significant risk factor for early AEs. Metal stents with a delivery diameter < 7.5 Fr can be inserted directly without the tract dilation step, resulting in lower early AE rates.

Endoscopic ultrasound-guided hepaticogastrostomy vs. antegrade metal stent placement keeping an access route in patients with malignant biliary obstruction.

BACKGROUND: Few studies have compared endoscopic ultrasound (EUS)-guided hepaticogastrostomy (HGS) with EUS-guided antegrade metal stent placement (AGMS). The purpose of this study was to compare times to recurrent biliary obstruction (TRBO) in patients who underwent HGS using metal stents (MS) and those who underwent AGMS keeping access routes with plastic stents (AGMS-AR). METHODS: This study retrospectively evaluated consecutive patients who underwent HGS or AGMS between September 2016 and December 2022. TRBO, overall survival (OS), and adverse event (AE) rates were compared in the two groups. The risk factors for RBO were determined using a multivariable Cox proportional hazards model. RESULTS: This study included 32 patients in the HGS group and 30 in the AGMS-AR group. Technical success rate was significantly higher in the HGS than in the AGMS-AR group (100 vs. 80%; P = 0.009). The technical success rate without tract dilation was significantly higher in the AGMS-AR than in the HGS group (83 vs. 38%; P < 0.001). RBO rates were significantly higher in the HGS than in the AGMS-AR group (53 vs. 17%; P = 0.024), whereas AE rates did not differ significantly. TRBO differed significantly in the HGS and AGMS-AR groups (159 days vs. not reached, P = 0.011), whereas OS did not differ significantly. Multivariable analysis revealed that HGS was an independent risk factor for RBO (hazard ratio, 6.48, P = 0.014). CONCLUSION: TRBO was significantly longer in patients who underwent AGMS with PS than HGS. AGMS with PS may be effective after the failure of ERCP in patients with malignant biliary obstruction.

Impact of sarcopenia on recurrent biliary obstruction after EUS-guided biliary drainage in patients with malignant biliary obstruction.

BACKGROUND AND AIMS: Sarcopenia is an important prognostic factor for cancer patients. The aim of this study was to assess the ability of sarcopenia to predict recurrent biliary obstruction (RBO) in patients with unresectable cancer after EUS-guided biliary drainage (EUS-BD). METHODS: The study enrolled 113 patients who underwent EUS-BD using the self-expandable metal stent (SEMS) for unresectable malignant biliary obstruction (MBO) between April 2016 and December 2021 at Wakayama Medical University Hospital. The skeletal muscle index at the third lumbar spine level (L3) was calculated from computed tomography images. We analyzed the cumulative incidence of RBO at 180 days after stent insertion. Univariate and multivariate analyses were performed to identify variables significantly associated with RBO. RESULTS: Seventy-six patients were assigned to the sarcopenia group, and 37 were assigned to the non-sarcopenia group. The 180-day cumulative incidence of RBO was 11% in the non-sarcopenia group and 29% in the sarcopenia group (p = 0.034). The time to RBO was significantly shorter for the sarcopenia group (p = 0.028; Gray's test). Multivariate analyses identified sarcopenia as an independent prognostic factor for RBO (present vs absent; HR 4.61; 95% CI 1.76-12.10, p = 0.001). The rates of biliary sludge/food impaction were significantly higher in the sarcopenia group for the causes of RBO (p = 0.048). There were no significant differences between the sarcopenia and the non-sarcopenia groups with respect to related EUS-BD adverse events. CONCLUSION: Sarcopenia is an independent indicator of RBO in patients with MBO who receive EUS-BD with SEMS.

Epigenetic Inhibitors as Alzheimer's Disease Therapeutic Agents.

Alzheimer's disease (AD) is the leading cause of senile dementia, and the rapid increase in the frequency of AD cases has been attributed to population aging. However, current drugs have difficulty adequately suppressing symptoms and there is still a medical need for symptomatic agents. On the other hand, it has recently become clear that epigenetic dysfunctions are deeply involved in the development of cognitive impairments. Therefore, epigenetics-related proteins have attracted much attention as drug targets for AD. Early-developed epigenetic inhibitors were inappropriate for AD treatment because of their limited potential for oral administration, blood-brain barrier penetration, high target selectivity, and sufficient dose-limiting toxicity which are essential properties for small molecule drugs targeting chronic neurodegenerative diseases such as AD. In recent years, drug discovery studies have been actively performed to overcome such problems and several novel inhibitors targeting the epigenetics-related proteins are of interest as promising AD therapeutic agents. Here, we review the small molecule inhibitors of histone deacetylase (HDAC), lysine-specific demethylase 1 (LSD1) or bromodomains and extra-terminal domain (BET) protein, that enable memory function improvement in AD model mice.

A Structure-Activity Relationship Study of SNAIL1 Peptides as Inhibitors of Lysine-Specific Demethylase 1.

Peptides have recently garnered attention as middle-molecular-weight drugs with the characteristics of small molecules and macromolecules. Lysine-specific demethylase 1 (LSD1) is a potential therapeutic target for lung cancer, neuroblastoma, and leukemia, and some peptide-based LSD1 inhibitors designed based on the N-terminus of SNAIL1, a member of the SNAIL/SCRATCH family of transcription factors, have been reported. The N-terminus of SNAIL1 peptide acts as a cap of the catalytic site of LSD1, inhibiting interactions with LSD1. However, the structure-activity relationship (SAR) of these inhibitors is not yet fully understood. Therefore, in the present study, we aimed to uncover the SAR and to identify novel SNAIL1 peptide-based LSD1 inhibitors. We synthesized peptide inhibitor candidates based on truncating the N-terminus of SNAIL1 or substituting its amino acid residues. In the truncation study, we found that SNAIL1 1-16 (2), which was composed of 16 residues, strongly inhibited LSD1. Furthermore, we investigated the SAR at residues-3 and -5 from the N-terminus and found that peptides 2j and 2k, in which leucine 5 of the parent peptide is substituted with unnatural amino acids, cyclohexylalanine and norleucine, respectively, strongly inhibited LSD1. This result suggests that the hydrophobic interaction between the inhibitor peptides and LSD1 affects the LSD1-inhibitory activity. We believe that this SAR information provides a basis for the development of more potent LSD1 inhibitors.

Identification of a Histone Deacetylase 8 Inhibitor through Drug Screenings Based on Machine Learning.

Histone deacetylase 8 (HDAC8) is a zinc-dependent HDAC that catalyzes the deacetylation of nonhistone proteins. It is involved in cancer development and HDAC8 inhibitors are promising candidates as anticancer agents. However, most reported HDAC8 inhibitors contain a hydroxamic acid moiety, which often causes mutagenicity. Therefore, we used machine learning for drug screening and attempted to identify non-hydroxamic acids as HDAC8 inhibitors. In this study, we established a prediction model based on the random forest (RF) algorithm for screening HDAC8 inhibitors because it exhibited the best predictive accuracy in the training dataset, including data generated by the synthetic minority over-sampling technique (SMOTE). Using the trained RF-SMOTE model, we screened the Osaka University library for compounds and selected 50 virtual hits. However, the 50 hits in the first screening did not show HDAC8-inhibitory activity. In the second screening, using the RF-SMOTE model, which was established by retraining the dataset including 50 inactive compounds, we identified non-hydroxamic acid 12 as an HDAC8 inhibitor with an IC50 of 842 nM. Interestingly, its IC50 values for HDAC1 and HDAC3-inhibitory activity were 38 and 12 µM, respectively, showing that compound 12 has high HDAC8 selectivity. Using machine learning, we expanded the chemical space for HDAC8 inhibitors and identified non-hydroxamic acid 12 as a novel HDAC8 selective inhibitor.

Identification of Proteolysis Targeting Chimeras (PROTACs) for Lysine Demethylase 5 and Their Neurite Outgrowth-Promoting Activity.

Lysine demethylase 5 (KDM5) proteins are involved in various neurological disorders, including Alzheimer's disease, and KDM5 inhibition is expected to be a therapeutic strategy for these diseases. However, the pharmacological effects of conventional KDM5 inhibitors are insufficient, as they only target the catalytic functionality of KDM5. To identify compounds that exhibit more potent pharmacological activity, we focused on proteolysis targeting chimeras (PROTACs), which degrade target proteins and thus inhibit their entire functionality. We designed and synthesized novel KDM5 PROTAC candidates based on previously identified KDM5 inhibitors. The results of cellular assays revealed that two compounds, 20b and 23b, exhibited significant neurite outgrowth-promoting activity through the degradation of KDM5A in neuroblastoma neuro 2a cells. These results suggest that KDM5 PROTACs are promising drug candidates for the treatment of neurological disorders.

Shear-wave versus strain elastography in endoscopic ultrasound for the diagnosis of chronic pancreatitis.

BACKGROUND: /Objectives: Endoscopic ultrasound (EUS) elastography is a non-invasive diagnostic method for evaluating tissue elasticity. The aims of this study were to compare shear-wave elastography (SWE) and conventional strain elastography (SE) in determination of the diagnosis and degree of chronic pancreatitis (CP). METHODS: Forty-nine patients who underwent computed tomography (CT), EUS-SWE, EUS-SE, and pancreatic exocrine function testing between January 2019 and January 2022 were prospectively evaluated. CP was diagnosed according to Japan Pancreatic Society criteria (JPSC) 2019, Rosemont criteria (RC), CT findings, and pancreatic exocrine dysfunction. The cut-off values, sensitivity, and specificity for CP diagnosed according to the four criteria were calculated for EUS-SWE and EUS-SE. Relationships between values measured by either of the EUS elastography methods and the number of EUS features were also assessed. RESULTS: EUS-SWE values were positively correlated with the severity grades of RC and JPSC, but EUS-SE values were not. EUS-SWE was significantly better than EUS-SE for diagnosing CP defined according to CT findings (area under the receiver operating characteristics curve [AUROC]: 0.77 vs. 0.61, P < 0.001), RC (AUROC: 0.85 vs. 0.56, P < 0.001), JPSC 2019 (AUROC: 0.83 vs. 0.53, P < 0.001), and exocrine dysfunction (AUROC: 0.78 vs. 0.61, P < 0.001). EUS-SWE values were positively correlated with the number of EUS features, but EUS-SE values were not. CONCLUSIONS: EUS-SWE provides objective assessment for diagnosing and assessing the degree of CP defined according to the criteria of CT findings, RC, JPSC, or exocrine dysfunction, and it can be considered a non-invasive diagnostic tool for CP and exocrine dysfunction.

Utility of contrast-enhanced harmonic endoscopic ultrasonography for prediction of pathological response after neoadjuvant chemotherapy in patients with pancreatic cancer.

OBJECTIVES: Contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) plays an important role in the diagnosis of pancreatic lesions. The aim of this study was to evaluate whether CH-EUS is useful for predicting the treatment efficacy of neoadjuvant chemotherapy (NAC) determined by pathological response. METHODS: Patients who underwent CH-EUS before chemotherapy and surgical resection were divided into two groups according to poor (group-P) or rich tumor vascularity (group-R) determined by enhancement pattern on early- and late-phase CH-EUS. The pathological response to chemotherapy was categorized according to Evans' classification. Pathological analysis showing tumor cell destruction (>50 %) defined a good response. RESULTS: Early-phase CH-EUS classified 44 patients into group-R and 50 into group-P, whereas late-phase CH-EUS classified 10 into group-R and 84 into group-P. Early-phase CH-EUS classification resulted in significantly higher numbers of patients with a good response in the rich group (n = 19) than in the poor group (n = 4; P = 0.0015). Multivariate analysis showed that assignment to the rich group was the strongest independent factor associated with chemosensitivity (P = 0.006, hazard ratio = 5.66, 95 % confidence interval: 1.17-19.27). In resectable patients, the enhancement pattern was the only independent factor associated with chemosensitivity (group-P vs. group-R, P = 0.003; HR [95 % CI], 14.59 [1.38-154.38]). Late-phase CH-EUS did not reveal a significant difference between group-P and group-R. CONCLUSIONS: Evaluation of vascular pattern on CH-EUS could be useful for predicting the efficacy of NAC in patients with pancreatic cancer. The enhancement pattern on CH-EUS could be a one of the useful features for determining NAC indications in resectable pancreatic cancer patients.

Uncovered versus covered expandable metal stents for malignant gastric outlet obstruction caused by intrinsic and extrinsic tumors: meta-analysis and meta-regression analysis.

BACKGROUND AND AIMS: Malignant gastric outlet obstruction (GOO) can be palliated by endoscopic placement of self-expandable metal stents (SEMSs). Studies comparing uncovered (USEMSs) and covered (CSEMSs) SEMSs have yielded inconclusive results. This meta-analysis compared USEMSs with CSEMSs in patients with GOO caused by intrinsic and extrinsic tumors. METHODS: Potentially relevant articles were identified by searching PubMed, the Cochrane Library, and Medline. The primary outcome was stent dysfunction. Relationships between characteristics of tumors causing GOO and the stent dysfunction rate following USEMSs and CSEMS placement were assessed. RESULTS: Overall, six randomized controlled trials and 12 observational studies, including 2431 patients, were identified. Rate of stent dysfunction did not differ significantly between USEMSs and CSEMSs (odds ratio [OR], 0.95; 95% confidence interval [CI], 0.73-1.25, I2 = 44%), but there was heterogeneity. Meta-regression analysis showed that heterogeneity of stent dysfunction was caused by a difference in the ratio of intrinsic-to-extrinsic tumors causing GOO between studies (coefficient, 0.944; 95% CI, 0.30-1.58). Studies were divided into intrinsic and extrinsic tumor groups. Subgroup analysis showed that the stent dysfunction rate did not differ between USEMSs and CSEMSs in the intrinsic tumor group (OR, 1.10; 95% CI, 0.85-1.41; I2 = 32%). In the extrinsic tumor group, USEMS was associated with a lower rate of stent dysfunction than CSEMS (OR, 0.64; 95% CI, 0.47-0.87; I2 = 25%). CONCLUSION: USEMS and CSEMS placement generally showed comparable outcomes among patients with GOO. USEMS was more effective than CSEMS for patients with GOO caused by extrinsic tumors.

Contrast-enhanced harmonic endoscopic ultrasonography for predicting the efficacy of first-line gemcitabine and nab-paclitaxel chemotherapy in pancreatic cancer.

BACKGROUND AND AIMS: The purpose of this study was to assess prognosis with different intratumoral vascularity on contrast-enhanced endoscopic harmonic ultrasonography (CH-EUS) in pancreatic cancer patients receiving chemotherapy. METHODS: Patients with unresectable pancreatic cancer who underwent CH-EUS before first-line gemcitabine and nab-paclitaxel (GEM and nab-PTX) therapy were classified into four groups according to vascularity on the early and late phases of contrast enhancement: "Group A″, poor on both phases; "Group B″, rich and poor on the early and late phases, respectively; "Group C″, poor and rich on the early and late phases; "Group D″, rich on both phases. Subgroups were compared in terms of progression-free survival (PFS) and overall survival (OS). We also assessed whether the results with CH-EUS correlate with those of contrast-enhanced computed tomography (CE-CT). RESULTS: On CH-EUS, 57, 64, 0, and 24 patients were classified into Groups A, B, C, and D, respectively. The median PFS of patients in groups A, B, and D was 3.9, 7.6, and 10.8 months, respectively, and the median OS were 9.5, 13.1, and 18.6 months, respectively. Both PFS and OS were longest in Group D (p < 0.001 and p < 0.001, respectively). The results of CE-CT were consistent with those of CH-EUS, and there was a correlation between CE-CT and CH-EUS. CONCLUSIONS: Evaluation of intratumoral vascularity by CH-EUS may be useful for predicting the efficacy of chemotherapy in patients with pancreatic cancer. A better response to GEM and nab-PTX can be expected in patients showing rich vascularity at both the early and late phases.

Impact of sarcopenia on prediction of progression-free survival and overall survival of patients with pancreatic ductal adenocarcinoma receiving first-line gemcitabine and nab-paclitaxel chemotherapy.

BACKGROUND AND AIMS: Sarcopenia is an important prognostic factor for cancer patients. Here, we assessed the effects of sarcopenia on progression-free survival (PFS) and overall survival (OS) of patients with pancreatic ductal adenocarcinoma (PDAC) who underwent treatment with first-line gemcitabine and nab-paclitaxel (GEM and nab-PTX). METHODS: The study enrolled patients with unresectable PDAC who underwent chemotherapy between April 2016 and May 2020. The skeletal muscle index (SMI) at the third lumbar spine level (L3) was calculated from computed tomography (CT) images. Propensity score analysis was used to compare PFS and OS in the sarcopenia and non-sarcopenia groups. Univariate and multivariate analyses were performed to determine variables significantly associated with prognosis. RESULTS: Of the 176 patients who received first-line GEM and nab-PTX, 84 were selected and divided into two groups of 42 (the sarcopenia and the non-sarcopenia groups) by propensity score matching. The median PFS of the sarcopenia and the non-sarcopenia groups was 5.0 and 8.0 months, respectively (p = 0.004). The median OS was 10.3 and 18.1 months, respectively (p = 0.001). Multivariate analyses revealed that sarcopenia was an independent prognostic factor for PFS and OS (p = 0.004, p = 0.001, respectively). The rates of major grade 3 or 4 AEs were significantly higher in the sarcopenia group (p = 0.008). CONCLUSIONS: Sarcopenia is an independent indicator of a poor prognosis in patients with PDAC treated with first-line GEM and nab-PTX.

Covered versus uncovered metal stent for endoscopic drainage of a malignant distal biliary obstruction: Meta-analysis.

OBJECTIVES: The role of a covered vs. an uncovered self-expandable metal stent (SEMS) for malignant distal biliary obstruction (MDBO) is not clear. This meta-analysis compared the efficacy of covered vs. uncovered SEMS for patients with MDBO after endoscopic insertion. METHODS: A systematic meta-analysis of all relevant articles listed in PubMed, the Cochrane Library, and Google Scholar databases was performed. Fixed effects or random effects models were used to investigate pooled effects with 95% confidence intervals (CIs). RESULTS: The meta-analysis included 2358 patients from 12 eligible studies. Time to recurrent biliary obstruction (RBO) was significantly longer for covered SEMS (mean difference, 45.51 days; 95% CI 11.79-79.24). Although there was no significant difference in the RBO rate, subgroup analysis in pancreatic cancer occupying more than 90% (PC) revealed that the RBO rates were significantly lower for covered SEMS (odds ratio [OR] 0.43, 95% CI 0.25-0.74). Stent migration, sludge formation, and overgrowth were significantly more common with a covered SEMS (OR 7.92, 95% CI 4.01-15.64; OR 3.25, 95% CI 1.89-5.59; OR 2.03, 95% CI 1.20-3.43, respectively). The rate of ingrowth was significantly lower for covered SEMS. There was no significant difference in total procedure-related adverse events between the two types of SEMS. CONCLUSIONS: A covered SEMS is superior to an uncovered SEMS with respect to prevention of RBO in patients with MDBO, particularly those caused by PC.

Identification of Novel Histone Deacetylase 6-Selective Inhibitors Bearing 3,3,3-Trifluorolactic Amide (TFLAM) Motif as a Zinc Binding Group.

Pharmacological inhibition of histone deacetylase 6 (HDAC6) is an effective therapeutic strategy for cancer and immunological diseases. Most of the previously reported HDAC6 inhibitors have a hydroxamate group as a zinc binding group (ZBG), which coordinates to the catalytic zinc ion of HDAC6. The hydroxamate group is liable to metabolically generate mutagenetic hydroxylamine; therefore, non-hydroxamate HDAC6 inhibitors would be advantageous. In this study, to identify novel non-hydroxamate HDAC6-selective inhibitors, screening of a chemical library and the subsequent structural optimization were performed, which led to the identification of HDAC6-selective inhibitors with 3,3,3-trifluorolactic amide (TFLAM) as a novel ZBG. The identified inhibitor showed potent and selective HDAC6-inhibitory activity in cells and induced regulatory T (Treg) cell differentiation.

Usefulness of a newly designed laser-cut metal stent with an anchoring hook and thin delivery system for EUS-guided hepaticogastrostomy in experimental settings (with video).

BACKGROUND AND AIMS: EUS-guided hepaticogastrostomy (EUS-HGS) is associated with high rates of adverse events. The present study evaluated the feasibility of a newly designed stent equipped with a dilatation and antimigration system for EUS-HGS in phantom and animal models. METHODS: The newly designed stent was a partially covered laser-cut stent with antimigration anchoring hooks and a thin tapered tip (7.2F). The feasibility of these stents for biliary obstruction was compared with that of conventional stents. Evaluated outcomes were resistance force to migration in phantom and ex vivo models, rates of technical success and adverse events, and histology in an in vivo model. RESULTS: The resistance forces on the distal (3.59 vs 1.73 N and 6.21 vs 1.74 N) and proximal (3.58 vs 1.5 N and 5.97 vs 1.67 N) sides in phantom and ex vivo models were significantly higher for hook stents than for conventional stents. Although EUS-HGS was successfully performed in all cases with both stents (100% [10/10] vs 100% [8/8]), the success rate of EUS-HGS without using a fistulous tract dilation device was significantly higher with hook stents (100% [10/10]) than with conventional stents (13% [1/8]). No adverse events occurred with either stent. Pathologic examination showed adhesion between the stomach and liver. CONCLUSIONS: The strong resistance to migration and the absence of the dilation step are important advantages of newly designed hook stents. These stents may therefore be feasible and safe for EUS-HGS.

Contrast-enhanced EUS for the characterization of mural nodules within pancreatic cystic neoplasms: systematic review and meta-analysis.

BACKGROUND AND AIMS: Pancreatic cystic neoplasms (PCNs) carry a considerable malignancy risk. Along with main duct dilation, the presence of enhanced mural nodules represents a significant risk factor for malignancy. Several articles assessed the role of contrast-enhanced EUS (CE-EUS) for the identification of malignant features in mural nodules. We evaluate the pooled diagnostic performance of CE-EUS for the identification of high-grade dysplasia or invasive carcinoma among mural nodules in PCNs. METHODS: A systematic review (Medline, PubMed, EMBASE) and meta-analysis were conducted. Subgroup analysis was used to assess the usefulness of a dedicated contrast-harmonic (CH-EUS). The primary outcome was pooled sensitivity for identification of high-grade dysplasia or invasive carcinoma. RESULTS: Ten studies (532 patients) were included. Pooled sensitivity of CE-EUS was 88.2% (95% confidence interval [CI], 82.7%-92.5%), specificity 79.1% (95% CI, 74.5%-83.3%), and diagnostic accuracy 89.6% (95% CI, 83.4%-95.8%). Eight studies (320 patients) were conducted using CH-EUS: pooled sensitivity increased to 97.0% (95% CI, 92.5%-99.2%), specificity to 90.4% (95% CI, 85.2%-94.2%), and diagnostic accuracy to 95.6% (95% CI, 92.6%-98.7%). At 42% disease prevalence (pretest probability), a positive CH-EUS increased the disease probability to 88%, whereas a negative test decreased the disease probability to 2%. The number needed to diagnose was 1.5 (95% CI, 1.7-1.3) for CE-EUS and just 1.2 (95% CI, 1.3-1.1) for CH-EUS. CONCLUSIONS: This study provided robust evidence on CE-EUS value for the characterization of mural nodules within PCNs. A dedicated contrast-harmonic mode, namely CH-EUS, provided an increased diagnostic yield in the identification and characterization of malignant mural nodules.

Endoscopic ultrasonography shear wave as a predictive factor of endocrine/exocrine dysfunction in chronic pancreatitis.

BACKGROUND AND AIM: Chronic pancreatitis (CP) leads to permanent impairment of exocrine and endocrine functions. The endoscopic ultrasonography (EUS)-based Rosemont classification plays an important role in diagnosing CP. However, it is based on subjective judgment. In contrast, EUS shear wave measurement (EUS-SWM) has been established to be a precise method for evaluating tissue hardness. This study aimed to evaluate the utility of EUS-SWM in diagnosing CP and determining exocrine and endocrine dysfunctions. METHODS: We evaluated 40 patients who underwent EUS-SWM between January 2019 and January 2020. They were classified into the normal pancreas and early, probable, and definite CP groups following the Japan Pancreatic Society criteria. EUS-SWM value was compared between the normal pancreas group and the early, probable, and definite CP groups. The relationship between EUS-SWM value and exocrine/endocrine dysfunctions was also assessed. The cut-off value of EUS-SWM for diagnosing CP and exocrine/endocrine dysfunctions was investigated. RESULTS: The EUS-SWM value was positively correlated with the Japan Pancreatic Society criteria stages. The probable and definite CP groups had significantly higher EUS-SWM values than the normal group. The areas under the receiver operating characteristic curve for the diagnostic accuracy of EUS-SWM for CP, exocrine dysfunction, and endocrine dysfunction were 0.92, 0.78, and 0.63, respectively. The cut-off values of 1.96, 1.96, and 2.34 for diagnosing CP, exocrine dysfunction, and endocrine dysfunctions had 83%, 90%, and 75% sensitivity, respectively, and 100%, 65%, and 64% specificity, respectively. CONCLUSIONS: Endoscopic ultrasonography shear wave measurement provides objective assessment and can thus be an alternative diagnostic tool for diagnosing CP and exocrine/endocrine dysfunctions.