Low-power pure-cut hot snare polypectomy for colorectal polyps 10-14 mm in size: a multicenter retrospective study

BACKGROUND AND AIM

Hot snare excision using electrocautery is widely used for large colorectal polyps (>10 mm); however, adverse events occur due to deep thermal injury. Colorectal polyps measuring 10-14 mm rarely include invasive cancer. Therefore, less invasive therapeutic options for this size category are demanding. We have developed hot snare polypectomy with low-power pure-cut current (LPPC HSP), which is expected to contribute to less deep thermal damage and lower risk of adverse events. This study aimed to evaluate the efficacy and safety of LPPC HSP for 10-14 mm colorectal polyps, compared with conventional endoscopic mucosal resection (EMR).

METHODS

In this multicenter, retrospective, observational study, clinical outcomes of EMR and LPPC HSP for 10-14 mm nonpedunculated colorectal polyps between January 2021 and March 2022 were compared using propensity score matching.

RESULTS

We identified 203 EMR and 208 LPPC HSP cases. After propensity score matching, the baseline characteristics between the groups were comparable, with 120 pairs. The en bloc and R0 resection rates were not significantly different between EMR and LPPC HSP groups (95.8% vs 97.5%, P = 0.72; 90.0% vs 91.7%, P = 0.82). The rates of delayed bleeding and perforation did not differ between the groups.

CONCLUSIONS

Compared with conventional EMR, LPPC HSP showed a similar resection ability without an increase in adverse events. These results suggest that LPPC HSP is a safe and effective treatment for 10-14 mm nonpedunculated colorectal polyps.

FOXA1/CK7-positive Esophageal Squamous Cell Carcinoma with Aggressive Liver Metastasis: A Case Report

Cytokeratin (CK) is a specific marker of adenocarcinoma. However, cases of CK7-positive esophageal squamous cell carcinoma (ESCC) have only rarely been reported. We herein report a case of unresectable CK7-positive ESCC with aggressive liver metastasis following nivolumab treatment initiation. Nivolumab treatment was discontinued after one course because of complications. Notably, the liver metastases exhibited accelerated growth. Immunostaining of the necropsy specimens revealed diffuse positivity for forkhead box protein A1 (FOXA1)/CK7, thus indicating a potent poor immune response. The potential correlation between CK7 expression and the immune checkpoint inhibitor response may offer valuable insights into the development of effective therapeutic strategies.

A case of early gastric cancer with metastatic recurrence following curative endoscopic submucosal dissection

A 70-year-old man was diagnosed with early gastric cancer with ulcerative findings. Endoscopic submucosal dissection as an absolute indication was performed, and en bloc resection was achieved. Pathological examination revealed a well-differentiated adenocarcinoma, 3 × 2 mm in size, intramucosal, with an ulcerative scar, no lymphovascular invasion, and a tumor-free margin. We diagnosed it as a curative resection and followed up with annual endoscopy. Sixteen months after endoscopic submucosal dissection, esophagogastroduodenoscopy revealed a singular ulcer scar; however, serum carcinoembryonic antigen level was elevated. Computed tomography scan showed wall thickening of the gastric antrum and an irregular mass on the dorsal side. Additionally, 18F-fluorodeoxyglucose positron emission tomography/coomputed tomography showed 18F-fluorodeoxyglucose uptake in the gastric antrum, irregular mass, and liver. Endoscopic ultrasonography revealed an internally heterogeneous mass in the gastric antrum region extending from the submucosal layer to the muscularis propria layer. Using an endoscopic ultrasonography-guided fine needle biopsy with a 22-gauge needle for the mass, we diagnosed local recurrence with the submucosal tumor-like appearance, lymph node metastasis, and liver metastases. Unfortunately, the patient died of gastric cancer 3 months after the diagnosis. Here, we report a rare case of local recurrence in the submucosal layer, lymph node metastasis, and liver metastases 16 months after curative endoscopic submucosal dissection.

Gel immersion endoscopic mucosal resection for early gastric neoplasms: a multicenter case series study

Several cases have been reported that suggest the efficacy of gel immersion endoscopic mucosal resection (GI-EMR) for gastric neoplasms. However, no study has evaluated treatment outcomes of GI-EMR for gastric neoplasms. This study aimed to investigate the efficacy and safety of GI-EMR for early gastric neoplasms. Nine patients (17 lesions) undergoing gastric GI-EMR were included, with a median lesion size of 10 mm (interquartile range [IQR] 5-13 mm). All lesions were protruding or flat elevated. The median procedure time was 3 minutes (IQR 2-5) and en bloc resection was achieved in all cases. Among 15 neoplastic lesions, the R0 resection rate was 86.7% (13/15 lesions). Adverse events included immediate bleeding requiring hemostasis in two cases, which was controlled endoscopically. No delayed bleeding or perforation occurred. In conclusion, GI-EMR may be a safe and effective treatment for early, small gastric neoplasms. However, due to the small sample in the present study, further investigation is required regarding the indication for this technique.

The diagnostic accuracy of endoscopic ultrasound-shear wave elastography in multiple pancreatic regions for chronic pancreatitis based on the Rosemont criteria

PURPOSE

Although endoscopic ultrasound (EUS) has been widely used for diagnosing chronic pancreatitis (CP), the assessment of fibrosis using the Rosemont criteria (RC) is generally subjective. Shear wave elastography using EUS (EUS-SWE) has been advocated as an objective approach to evaluating pancreatic fibrosis; however, it is unknown which pancreatic region should be selected for measurement. This study aims to compare the diagnostic accuracy in diagnosing CP by measurement site.

METHODS

Fifty patients with CP or suspected CP who underwent EUS-SWE were retrospectively analyzed. As per the RC, they were classified into two groups: CP and non-CP. Pancreatic stiffness was evaluated by measuring the velocities of the shear wave (Vs) in addition to determining the relevant cutoff value of Vs for diagnosing CP. The correlation between Vs and RC, and the RC factors affecting pancreatic stiffness were evaluated.

RESULTS

In the CP group, the Vs were notably higher in all regions (P < 0.001). The Vs for diagnostic accuracy of CP were highest in the body [area under the curve (AUC): 0.87]. A significant correlation was seen between the number of RC and Vs in all regions, with the correlation coefficient being highest in the pancreatic body (rs = 0.55). Multivariate analysis revealed that lobularity with honeycombing was an independent factor for pancreatic stiffness (P = 0.02).

CONCLUSION

The pancreatic body is a suitable region for assessing pancreatic stiffness using EUS-SWE. Additionally, quantifying Vs is a valuable objective indicator for diagnosing CP.

Comparison of quality of life and psychological distress in patients with tongue cancer undergoing a total/subtotal glossectomy or extended hemiglossectomy and free flap transfer: a prospective evaluation

The aim of this study was to assess changes in the quality of life and psychological distress of patients with tongue cancer undergoing total/subtotal glossectomy (TG) or extended hemiglossectomy (HG) and free flap transfer. Differences between the two groups were compared using the Short Form 8-Item Health Survey (SF-8) and Hospital Anxiety and Depression Scale (HADS). Of the 43 patients with tongue cancer, 24 (56%) underwent TG and 19 (44%) underwent HG. The general health and social functioning scores in the SF-8 and depression in the HADS were significantly worse in the TG group than in the HG group at 12 months after surgery, indicating that patients in the TG group may experience social isolation and psychological distress, and have difficulty in employability even 12 months after surgery. In contrast, all items of the SF-8 in the HG group were nearly equal to those in the general population. Due to the extensive psychological impact on patients with tongue cancer who are planned for an extended resection, curative surgery with free flap transfer and multidisciplinary psychiatric support are essential to improve quality of life and manage psychological distress.

Serum-Stable and Selective Backbone-N-Methylated Cyclic Peptides That Inhibit Prokaryotic Glycolytic Mutases

N-Methylated amino acids (N-MeAAs) are privileged residues of naturally occurring peptides critical to bioactivity. However, de novo discovery from ribosome display is limited by poor incorporation of N-methylated amino acids into the nascent peptide chain attributed to a poor EF-Tu affinity for the N-methyl-aminoacyl-tRNA. By reconfiguring the tRNA's T-stem region to compensate and tune the EF-Tu affinity, we conducted Random nonstandard Peptides Integrated Discovery (RaPID) display of a macrocyclic peptide (MCP) library containing six different N-MeAAs. We have here devised a "pool-and-split" enrichment strategy using the RaPID display and identified N-methylated MCPs against three species of prokaryotic metal-ion-dependent phosphoglycerate mutases. The enriched MCPs reached 57% N-methylation with up to three consecutively incorporated N-MeAAs, rivaling natural products. Potent nanomolar inhibitors ranging in ortholog selectivity, strongly mediated by N-methylation, were identified. Co-crystal structures reveal an architecturally related Ce-2 Ipglycermide active-site metal-ion-coordinating Cys lariat MCP, functionally dependent on two cis N-MeAAs with broadened iPGM species selectivity over the original nematode-selective MCPs. Furthermore, the isolation of a novel metal-ion-independent Staphylococcus aureus iPGM inhibitor utilizing a phosphoglycerate mimetic mechanism illustrates the diversity of possible chemotypes encoded by the N-MeAA MCP library.

Absence of the Anterior Communicating Artery on Selective MRA is Associated with New Ischemic Lesions on MRI after Carotid Revascularization

BACKGROUND AND PURPOSE

ICA-selective MRA using a pencil beam presaturation pulse can accurately visualize anterior communicating artery flow. We evaluated the impact of anterior communicating artery flow on the perioperative hemodynamic status and new ischemic lesions after carotid revascularization.

MATERIALS AND METHODS

Eighty-three patients with carotid artery stenosis were included. We assessed anterior communicating artery flow using ICA-selective MRA. The preoperative hemodynamic status was measured using SPECT. We also measured the change in regional cerebral oxygen saturation after temporary ICA occlusion. New ischemic lesions were evaluated by DWI on the day after treatment.

RESULTS

Anterior communicating artery flow was detected in 61 patients, but it was not detected in 22 patients. Preoperative cerebrovascular reactivity was significantly higher in patients with (versus without) anterior communicating artery flow with a mean peak systolic velocity of ≥200 cm/s (39.6% [SD, 23.8%] versus 25.2% [SD, 16.4%]; P = .030). The decrease in mean regional cerebral oxygen saturation was significantly greater in patients without (versus with) anterior communicating artery flow (8.5% [SD, 5.6%] versus 3.7% [SD, 3.8%]; P = .002). New ischemic lesions after the procedure were observed in 23 patients. The multivariate logistic regression analysis revealed that anterior communicating artery flow (OR, 0.07; 95% CI, 0.012-0.45; P = .005) was associated with new ischemic lesions.

CONCLUSIONS

The absence of anterior communicating artery flow influenced the perioperative hemodynamic status in patients with carotid stenosis and was associated with an increased incidence of new ischemic lesions after carotid revascularization.

Prevalence of and risk factors for depressive symptoms in non-tuberculous mycobacterial pulmonary disease

BACKGROUND: The presence of depressive symptoms in patients with non-tuberculous mycobacterial pulmonary disease (NTM-PD) is an important research topic; however, the prevalence of depressive symptoms and the factors that influence their development are unclear.OBJECTIVE: To analyse the association between CES-D (Center for Epidemiological Studies Depression Scale) scores and clinical parameters such as age, disease duration, pulmonary function, imaging findings, blood data, physical functions, sleep disturbances, respiratory symptoms and health-related quality of life (HRQOL).METHODS: We conducted a cross-sectional retrospective study of 114 patients with NTM-PD at a single centre from March 2016 to January 2021 to evaluate the relationship between CES-D scores and clinical parameters.RESULTS: Participants had a median age of 64 years; 32.5% of them had depressive symptoms. Disease duration, albumin, C-reactive protein, pulmonary function, dyspnoea, exercise capacity, respiratory symptoms, cough-related HRQOL and sleep disturbances were associated with depressive symptoms. Binomial logistic regression analyses indicated that the CES-D score was significantly associated with cough-related HRQOL and sleep disturbances.CONCLUSION: A high percentage of NTM-PD patients in this study experienced depressive symptoms, and these patients had abnormalities of various clinical parameters. Cough-related HRQOL and sleep disturbance had a strong influence on the development of depressive symptoms.

Efficacy of endoscopic samplings during initial biliary drainage for cases of pancreatic head cancer: United diagnostic yields of multiple pathological samplings

BACKGROUND/OBJECTIVES

The diagnostic ability of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has been fully studied; however, the efficacy of other endoscopic samplings (OESs) is less clear. The aim of this study was to examine the diagnostic efficacies of OESs for pancreatic head cancer (PHC).

METHODS

The diagnostic efficacies of endoscopic samplings were retrospectively analyzed in 448 PHC cases and 63 cases of mass-forming pancreatitis (MFP) during initial transpapillary biliary drainage. The OESs included duodenal biopsy (118 PHCs and 50 MFPs), biliary biopsy (218 and 51) with cytology (368 and 53), and pancreatic duct biopsy (23 and 13) with cytology (56 and 43). EUS-FNA was conducted in a different session (149 and 62). Factors associated with OES sensitivity were analyzed. The sensitivity of biliary biopsy was compared between 1.95 mm and 1.8 mm forceps.

RESULTS

Cancer cells were confirmed in 87.9% of the EUS-FNA samplings and in 64.1% (268/418) obtained by combined OESs (average 1.7 OES types per case): 68.6% by duodenal biopsy, 59.6% by biliary biopsy, 32.6% by biliary cytology, 73.9% by pancreatic duct biopsy, and 33.9% by pancreatic duct cytology. No MFP cases revealed cancer by any sampling. OESs did not increase adverse events. Duodenal stenosis, serum bilirubin, tumor size, and pancreatic juice amounts were associated with OES sensitivity. Biliary biopsy had the same sensitivity with different forceps.

CONCLUSION

EUS-FNA was the most diagnostic protocol; however, OESs can be safely applied during the initial biliary drainage to reduce the demand for EUS-FNA while providing good diagnostic yields.

Features of post-endoscopic submucosal dissection electrocoagulation syndrome for early gastric neoplasm

BACKGROUND AND AIM

Post-endoscopic submucosal dissection electrocoagulation syndrome (PECS) has become a common adverse event after colorectal endoscopic submucosal dissection (ESD) and esophageal ESD. However, little is known about PECS after gastric ESD. Therefore, this study aimed to investigate the clinical features of PECS after gastric ESD.

METHODS

Patients who underwent ESD for gastric cancer or adenoma between January 2016 and December 2017 were retrospectively investigated. PECS was clinically diagnosed based on the presence of upper abdominal pain and localized abdominal tenderness with a temperature of >37.5°C, without perforation. We analyzed the clinical features of PECS.

RESULTS

A total of 637 ESD cases were enrolled; PECS occurred in 32 patients (5.0%), all of whom were diagnosed on postoperative Day 1. Among PECS cases, unplanned prolongation of hospitalization or fasting period was observed in 15 patients (47%). As a result, the median durations of hospitalization and fasting period were significantly longer in PECS cases (P = 0.008 and P < 0.001, respectively); however, the mean differences were less than a day. Additionally, all PECS cases recovered with conservative treatment.

CONCLUSIONS

PECS is considered a common adverse event after gastric ESD. More than half of patients with PECS could start diets and be discharged as well as those without PECS.

URAT1-selective inhibition ameliorates insulin resistance by attenuating diet-induced hepatic steatosis and BAT whitening in mice

Background

Accumulating evidence suggests that high uric acid is strongly associated with obesity and metabolic syndrome and drives the development of non-alcoholic fatty liver disease (NAFLD) and insulin resistance. Although urate transporter-1 (URAT1), which is primarily expressed in the kidney, plays a critical role in the development of hyperuricemia, its pathophysiological implication in NAFLD and insulin resistance remains unclear.

Objectives

We hypothesizes that URAT1 plays an important role in obesity-induced metabolic disorders, and URAT1-selective inhibitor treatment ameliorates systemic insulin resistance, NAFLD and adipose tissue dysfunction using diet-induced obese mice.

Methods

Mice fed a high-fat diet (HFD) for 16 to 18 weeks or a normal-fat diet (NFD) were treated with or without a novel oral URAT1-selective inhibitor (dotinurad [50 mg/kg/day]) for another 4 weeks.

Results

Dotinurad administration significantly ameliorated HFD-induced obesity and insulin resistance. We found that URAT1 was also expressed in the liver and brown adipose tissue (BAT) other than kidney. HFD markedly induced NAFLD, which was characterized by severe hepatic steatosis, as well as the elevation of serum ALT activity and tissue inflammatory cytokine genes (Ccl2 and TNFα), all of which were attenuated by dotinurad. Likewise, HFD significantly increased URAT1 expression in BAT, resulting in the lipid accumulation (whitening of BAT) and increased production of tissue reactive oxygen species, which were reduced by dotinurad via UCP1 activation.

Conclusions

A novel URAT1-selective inhibitor, dotinurad, ameliorates insulin resistance by attenuating hepatic steatosis and promoting rebrowning of lipid-rich BAT in HFD-induced obese mice. URAT1 serves as a key regulator of the pathophysiology of metabolic syndrome, and may be a new therapeutic target for insulin-resistant individuals, particularly those with concomitant NAFLD.

Funding Acknowledgement

Type of funding sources: None.

Discovery of N-(6-(5-fluoro-2-(piperidin-1-yl)phenyl)pyridazin-3-yl)-1-(tetrahydro-2H-pyran-4-yl)methanesulfonamide as a brain-permeable and metabolically stable kynurenine monooxygenase inhibitor

Kynurenine monooxygenase (KMO) is expected to be a good drug target to treat Huntington's disease (HD). This study presents the structure-activity relationship of pyridazine derivatives to find novel KMO inhibitors. The most promising compound 14 resolved the problematic issues of lead compound 1, i.e., metabolic instability and reactive metabolite-derived side-effects. Compound 14 exhibited high brain permeability and a long-lasting pharmacokinetics profile in monkeys, and neuroprotective kynurenic acid was increased by a single administration of 14 in R6/2 mouse brain. These results demonstrated 14 may be a potential drug candidate to treat HD.

Long-term outcomes of salvage endoscopic submucosal dissection for local failure after chemoradiotherapy for esophageal squamous cell carcinoma

BACKGROUND

Salvage endoscopic submucosal dissection is considered a minimally invasive treatment for local failure after chemoradiotherapy for esophageal squamous cell carcinoma. However, the long-term outcomes have not been fully evaluated. This study investigated the short-term and long-term outcomes of salvage endoscopic submucosal dissection.

METHODS

Patients who underwent endoscopic submucosal dissection for local recurrence or residual tumor after chemoradiotherapy from January 2006 to December 2017 were retrospectively investigated. Follow-up included endoscopic examination and computed tomography at least once every 6 months after salvage endoscopic submucosal dissection. Risk factors for disease recurrence after salvage endoscopic submucosal dissection were assessed using the Cox hazards model.

RESULTS

A total of 30 patients (33 cases of esophageal squamous cell carcinoma: local recurrence, n = 27; residual tumor, n = 6) were included. The median endoscopic submucosal dissection procedure time was 40 min (interquartile range [IQR], 33-58.5 min). En bloc resection was achieved in 31 (94%) of 33 esophageal squamous cell carcinoma cases. One patient with intraoperative perforation did not require surgical intervention and recovered with conservative treatment. A total of 16 patients (53%) had disease recurrence at a median follow-up of 51 months (IQR, 33-81 months). The 3-year overall, disease-specific, recurrence-free and local recurrence-free survival rates were 75%, 82%, 58% and 90%, respectively. The positive vertical margin, submucosal invasion in the endoscopic submucosal dissection specimen and piecemeal resection were significantly associated with disease recurrence after salvage endoscopic submucosal dissection.

CONCLUSIONS

Salvage endoscopic submucosal dissection is a feasible treatment for local failure after chemoradiotherapy for esophageal squamous cell carcinoma with acceptable long-term outcomes. However, for cases with positive vertical margins and submucosal invasion in the endoscopic submucosal dissection specimen, salvage endoscopic submucosal dissection outcomes were insufficient and additional treatment might be required.

Health-related quality of life associates with clinical parameters in patients with NTM pulmonary disease

BACKGROUND: Previous studies have shown a reduction in health-related quality of life (HRQoL) in patients with non-tuberculous mycobacterial pulmonary disease (NTM-PD). However, the causes of this decline and the factors that contribute to it are unknown. This study was conducted to analyse the association between the St George´s Respiratory Questionnaire (SGRQ) and clinical parameters, including age, disease duration, body composition, pulmonary function, chest X-ray findings, blood data and physical function.METHODS: We performed a single-centre, cross-sectional, retrospective study of 101 patients with NTM-PD from December 2016 to October 2019. The relationship between the SGRQ scores and clinical parameters was evaluated.RESULTS: The median patient age was 67.0 years. Pulmonary function, radiological score, albumin levels, C-reactive protein levels and incremental shuttle walk test distance (ISWD) were significantly correlated with the total and component scores on the SGRQ. Multiple regression analysis showed that the SGRQ score was significantly associated with radiological score, pulmonary function and ISWD.CONCLUSION: This study was the first to assess the effect of clinical parameters on the SGRQ in patients with NTM-PD. HRQoL as determined using the SGRQ was associated with the radiological score, pulmonary function and ISWD in patients with NTM-PD.

N-(6-phenylpyridazin-3-yl)benzenesulfonamides as highly potent, brain-permeable, and orally active kynurenine monooxygenase inhibitors

Huntington's disease (HD) is one of the serious neurodegenerative diseases and no disease modifiers are available to date. The correction of unbalanced kynurenine pathway metabolites may be useful to treat disease progression and kynurenine monooxygenase (KMO) is considered an ideal drug target. A couple of KMO inhibitors have been reported, but their brain permeability was very poor. We found pyridazinylsulfonamide as a novel lead compound, and it was optimized to the brain-permeable and highly potent KMO inhibitor 12, which was equipotent with CHDI-340246 and superior to CHDI-340246 in terms of brain penetration. Compound 12 was effective in R6/2 mice (HD model mice), i.e. neuroprotective kynurenic acid was increased, whereas neurotoxic 3-hydroxykynurenine was suppressed. In addition, impaired cognitive function was improved. Therefore, the brain-permeable KMO inhibitor was considered to be a disease modifier for HD treatment.

Xanthine oxidase inhibition attenuates doxorubicin-induced cardiotoxicity in mice

Background

Accumulating evidence suggests that high serum uric acid (UA) is associated with left ventricular (LV) dysfunction. Although xanthine oxidase (XO) activation is a critical regulatory mechanism of the terminal step in ATP and purine degradation, the pathophysiological role of cardiac tissue XO in LV dysfunction remains unclear.

Objectives

We hypothesized that cardiac XO is activated in doxorubicin-induced LV dysfunction, and XO inhibitors ameliorate LV function by inhibiting cell death signals as well as by modifying cardiac purine metabolism.

Methods

Either doxorubicin (10 mg/kg) or vehicle was intraperitonially administered in a single injection to ICR mice. Mice were treated with or without oral XO inhibitors (febuxostat 3 mg/kg/day or topiroxostat 5 mg/kg/day) for 8 days starting 24 hours before doxorubicin-injection. The LV function was assessed by echocardiography at day 6 and by ex vivo heart perfusion at day 7.

Results

Cardiac tissue XO activity measured by a highly sensitive assay with liquid chromatography/mass spectrometry (n=8 each) and cardiac UA content (n=3–6) were significantly increased in doxorubicin-treated mice at day 7 and dramatically reduced by XO inhibitors. Accordingly, XO inhibitors substantially improved LV ejection fraction (n=8 each) and LV developed pressure (n=9 each) that had been impaired by doxorubicin administration. Intriguingly, the expression of GPX4, a negative regulator of ferroptosis, was decreased in doxorubicin-treated hearts but improved by XO inhibitors (n=6 each). Furthermore, metabolome analyses revealed an enhanced purine metabolism in doxorubicin-treated hearts, and XO inhibitors suppressed the serial metabolic reaction of hypoxanthine–xanthine–UA.

Conclusions

Doxorubicin administration induces cardiac tissue XO activation associated with an impaired LV function. XO inhibition attenuates the doxorubicin-induced cardiotoxicity partly through an anti-ferroptotic effect and the conservation of tissue ATP levels by modulating purine metabolism. The present study suggests that pharmacological XO inhibition represents a potential therapeutic strategy for the treatment of doxorubicin-induced cardiotoxicity.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): This study was supported in part by grants-in-aid for Ministry of Education Culture, Sports, Science and Technology.

Single-molecule imaging reveals control of parental histone recycling by free histones during DNA replication

During replication, nucleosomes are disrupted ahead of the replication fork, followed by their reassembly on daughter strands from the pool of recycled parental and new histones. However, because no previous studies have managed to capture the moment that replication forks encounter nucleosomes, the mechanism of recycling has remained unclear. Here, through real-time single-molecule visualization of replication fork progression in Xenopus egg extracts, we determine explicitly the outcome of fork collisions with nucleosomes. Most of the parental histones are evicted from the DNA, with histone recycling, nucleosome sliding, and replication fork stalling also occurring but at lower frequencies. Critically, we find that local histone recycling becomes dominant upon depletion of endogenous histones from extracts, revealing that free histone concentration is a key modulator of parental histone dynamics at the replication fork. The mechanistic details revealed by these studies have major implications for our understanding of epigenetic inheritance.

0141 A Novel, Orally Available Orexin 2 Receptor-Selective Agonist, TAK-994, Shows Wake-Promoting Effects Following Chronic Dosing in an Orexin-Deficient Narcolepsy Mouse Model

Introduction

The use of an orexin 2 receptor (OX2R) agonist may be a promising approach for the treatment of narcolepsy type 1. TAK-994 is a novel, orally available OX2R-selective agonist with &gt;700-fold selectivity against orexin 1 receptor. Single administration of TAK-994 ameliorates narcolepsy-like symptoms such as fragmentation of wakefulness and cataplexy-like episodes in orexin/ataxin-3 mice, a narcolepsy mouse model with orexin deficiency. In this study, we evaluated the effect of chronic dosing with TAK-994 on sleep/wakefulness states in orexin/ataxin-3 mice.

Methods

Orexin/ataxin-3 mice were grouped into two cohorts: a control group and a 14-day treatment group. In the control group, vehicle was administered orally to mice three times a day: zeitgeber time 12 (ZT12), ZT15 and ZT18, for 14 days. In the 14-day treatment group, TAK-994 was administered orally to mice at ZT12, ZT15 and ZT18 for 14 days. Electroencephalogram/electromyogram analysis was performed on day 1 and day 14 (ZT12-ZT21), and the subsequent sleep phase (ZT0-ZT10).

Results

On day 1, TAK-994 significantly increased wakefulness time, accompanied by a decrease in non-rapid eye movement (NREM) sleep time and rapid eye movement (REM) sleep time, in orexin/ataxin-3 mice compared with the control group. On day 14, TAK-994 also significantly increased wakefulness time, and decreased NREM sleep time and REM sleep time in orexin/ataxin-3 mice. There were no changes in the time spent in wakefulness, NREM sleep and REM sleep during the subsequent sleep phase after chronic dosing with TAK-994.

Conclusion

Wake-promoting effects of TAK-994 were observed following chronic dosing for up to 14 days in orexin/ataxin-3 mice with no rebound of sleep. Overall, there was no clear difference in efficacy between the single and repeated administration of TAK-994 in orexin/ataxin-3 mice.

Support

This work was conducted by Takeda Pharmaceutical Company Limited.

0142 TAK-925, an Orexin 2 Receptor-Selective Agonist, Enhanced Cortical Arousal in a Narcolepsy Mouse Model Different from Effects of Modafinil

Introduction

Patients with narcolepsy type 1 (NT1) suffer from distressing symptoms such as excessive daytime sleepiness (EDS) and cataplexy. Modafinil is widely used as a therapy for NT1; however, it has limited efficacy for EDS and no efficacy for cataplexy. TAK-925 is an orexin 2 receptor (OX2R)-selective agonist which improves multiple symptoms of narcolepsy such as fragmentation of wakefulness and cataplexy-like episodes, and also reduces weight gain, in orexin/ataxin-3 mice, a narcolepsy mouse model. An early proof of concept study showed TAK-925 increased wakefulness compared to placebo in individuals with NT1; however, a head-to-head comparison between TAK-925 and modafinil in NT1 has not been performed to date. In this study, we carefully compared the wake-promoting effects of TAK-925 and modafinil in orexin/ataxin-3 mice.

Methods

TAK-925 or modafinil was administered to orexin/ataxin-3 mice at zeitgeber time 12, and the sleep/wakefulness states were evaluated based on electroencephalogram (EEG) and electromyogram measurements. EEG spectral analysis was performed by fast Fourier transform during wakefulness. EEG frequency band was divided into five frequency bands: delta, theta, alpha, beta, and gamma.

Results

Both TAK-925 and modafinil significantly increased wakefulness time, and ameliorated fragmentation of wakefulness, in orexin/ataxin-3 mice during active phase. In contrast, TAK-925, but not modafinil, significantly decreased delta power, and increased alpha and gamma power during wakefulness in orexin/ataxin-3 mice, suggesting a shift in EEG power density toward higher frequencies.

Conclusion

TAK-925, but not modafinil, enhanced cortical arousal and suppressed signs of somnolence and drowsiness. In a phase 1 study in individuals with NT1, TAK-925 was found to have pronounced effects on the maintenance of wakefulness test, reaching a total duration of 40 minutes wake time at some doses tested. Spectral analysis will be evaluated in future studies in NT1 patients.

Support

This work was conducted by Takeda Pharmaceutical Company Limited.

Preoperative indicators of misdiagnosis in invasion depth staging of esophageal cancer: Pitfalls of magnifying endoscopy with narrow-band imaging

OBJECTIVES

The Japan Esophageal Society classification has been widely applied for predicting the invasion depth of superficial esophageal squamous cell carcinomas (SESCCs). Although Type B2 of the classification clinically corresponds to SESCCs with muscularis mucosa or slight submucosal invasion (MM/SM1), diagnostic yield based on Type B2 is insufficient. This study aimed to investigate risk factors for misdiagnosis in preoperative invasion depth staging.

METHODS

We included a total of 104 SESCCs in which Type B2 was observed by magnifying endoscopy. SESCCs were classified as either correct diagnosis (pMM/SM1, 39 lesions), overdiagnosis (epithelium or the lamina propria [pEP/LPM], 34 lesions), or underdiagnosis (deep invasion into the submucosa [pSM2-3], 31 lesions) based on pathological depth of invasion. The association between misdiagnosis and endoscopic features, including distinct features, was evaluated using logistic regression analysis. Distinct features were defined as nodular protrusion, thickness, and/or clearly depressed area. The diameter of type B2 area was endoscopically measured, and the cut-off value was determined using a receiver operating characteristic curve.

RESULTS

Type B2 area <6 mm (area under the curve, 0.776) and Type B2 vessels around erosion were significantly associated with overdiagnosis (odds ratio, 16.6 and 11.0, respectively), while distinct features were significantly associated with underdiagnosis (odds ratio, 8.7). Adjusted by these misdiagnosis factors, positive predictive value of Type B2 significantly improved from 38% to 65% (P < 0.01).

CONCLUSIONS

Lesions with a small Type B2 area (<6 mm) and/or Type B2 vessels around erosion should be diagnosed as EP/LPM and lesions with distinct features as SM2-3.

Oral function and vertical jump height among healthy older people in Japan

OBJECTIVE

Vertical jump height and oral function affect the general muscle condition. This study aimed to evaluate the association between vertical jump height and oral function among healthy older individuals.

BASIC RESEARCH DESIGN

Cross-sectional analytic study.

PARTICIPANTS

231 independent older people (mean age, 74.4 ± 5.6 years) who participated in the Kyoto Elders Physical Fitness Measurement Research Project. Individuals with partial or complete edentulousness who did not use a prosthetic device or complained of oral/maxillofacial pain were excluded from the study.

INTERVENTIONS

Grip strength was measured using a Smedley Hand Dynamometer. To measure masticatory performance, the participants were instructed to chew a gummy jelly on their habitual chewing side (left or right) for 20 s. Occlusal force, contact area, and pressure were also assessed.

MAIN OUTCOME MEASURES

The outcome variable was vertical jump height. The predictor variables were physical status (age, body mass index, and grip strength), oral status (number of present teeth and denture use), and oral function (masticatory performance, occlusal force, occlusal contact area, occlusal pressure, and tongue pressure). These relationships were evaluated with univariate analysis, and then multiple regression analysis was performed with age as the covariate for each male and female participant.

RESULTS

Vertical jump height was significantly associated with grip strength in both men and women. Moreover, in women, it was associated with masticatory performance, occlusal force, and occlusal contact area.

CONCLUSIONS

Vertical jump height was closely associated with oral function among healthy older women.

DWI for Monitoring the Acute Response of Malignant Gliomas to Photodynamic Therapy

BACKGROUND AND PURPOSE

Photodynamic therapy is a novel treatment that provides effective local control, but little is known about photodynamic therapy-induced changes on MR imaging. The aim of this study was to assess the utility of DWI and ADC in monitoring the response of malignant gliomas to photodynamic therapy.

MATERIALS AND METHODS

Time-dependent changes in DWI and ADC values after photodynamic therapy were analyzed in a group that received photodynamic therapy in comparison with a group that did not.

RESULTS

Twenty-four patients were enrolled (photodynamic therapy, n = 14; non-photodynamic therapy, n = 10). In all patients who received photodynamic therapy, linear high signals on DWI in the irradiated area were detected adjacent to the resection cavity and were 5-7 mm in depth from 1 day posttreatment and disappeared in about 30 days without any neurologic deterioration. The non-photodynamic therapy group did not show this change. The photodynamic therapy group had significantly lower ADC values from 1 day posttreatment (P < .001), which increased steadily and disappeared by 30 days. There was no decline or time-dependent change in ADC values in the non-photodynamic therapy group.

CONCLUSIONS

The acute response of malignant gliomas to photodynamic therapy was detected as linear high signals on DWI and as a decrease in ADC values. These findings were asymptomatic and transient. Although the photodynamic therapy-induced acute response on MR imaging disappeared after approximately 30 days, it may be helpful for confirming the photodynamic therapy-irradiated area.

P1809Impact of mitral regurgitation on clinical outcome in patients with cardiac sarcoidosis

Background

Mitral regurgitation (MR) is sometimes observed in cardiac sarcoidosis (CS), and might be related to worsening heart failure. However, mechanism and clinical significance of MR associated with CS remains undetermined.

Methods

We retrospectively analyzed consecutive 51 CS patients, and identified 16 patients with moderate to severe MR evaluated by quantitative echocardiography. According to the assessment of coaptation point and tenting height, main mechanisms of the 16 patients with MR were classified into prolapse (P) in 5, and tethering in 11 (T). Prednisolone was started from 30 mg/day, gradually tapered over a period of 6 months to a maintenance dose of 5 to 10 mg/day and continued a lifetime.

Results

At the first visit, patients with MR showed higher incidence of NYHA class IV heart failure as compared to those without MR (56 vs. 9%, p<0.001). Abnormal uptake of fluorine-18 fluorodeoxyglucose in the papillary muscle was more frequent in patients with MR than those without MR (63% vs. 23%, p<0.05). Patients with tethering MR showed higher incidence of complete atrioventricular block (T: 74% vs. P: 40% vs. without MR: 31%, p<0.05), significantly reduced left ventricular (LV) ejection fraction (T: 33±7% vs. P: 52±9% vs. without MR: 52±16%, p<0.001) and increased LV end-diastolic volume index (T: 100±52ml/m2 vs. P: 66±23ml vs. without MR: 62±21ml, p<0.001). During the mean follow-up of 108 months, cardiac-event free survival was significantly worse in patients with tethering MR as compared to the other patients (log-rank; 11.7, p<0.001). Six of the 11 patients with tethering MR received cardiac resynchronization therapy, and then did not experience further hospitalization due to decompensated heart failure for at least 2 years. Multivariate analysis identified tethering MR as an independent predictor of cardiac event (HR: 6.7, p<0.05).

Conclusions

MR associated with CS has variety of mechanisms including prolapse, tethering and inflammation of the LV papillary muscle, and may be related to ventricular remodeling and poor clinical outcome.

Performance verification of a precise vibrating-wire magnet alignment technique for next-generation light sources

The high-accuracy alignment of magnets is a key issue in the development of next-generation light-source rings. To obtain adequate dynamic apertures, the magnets must be aligned to an accuracy of 10 µm or better. Recently, a new technique that utilizes a vibrating wire has attracted attention for this purpose as it can directly determine with high resolution the magnetic centers in a series of multipole magnets on a straight section between bending magnets. In conventional vibrating-wire alignment techniques, wire sag, which causes alignment errors, is determined from the theoretical catenary curve. By contrast, in the present study, we have measured the sag profiles of various wires in the longitudinal direction to micrometer-order accuracy. We concluded that we can reduce deviations of the actual wire sag from the theoretical curve by choosing a suitable wire. By setting up a test bench of a vibrating-wire alignment system for a series of multipole magnet on a straight section, we have achieved the total error of the magnetic-center measurements of micrometer-order in the standard deviation. Moreover, two systematic error factors, the drift of the magnetic centers due to thermal deformations of the magnets after they are excited and the change in the magnetic centers due to reassembly of the magnets after installing the vacuum chamber, are included in practical magnet alignments. We have experimentally investigated these error factors using the test bench.

An open-type microdevice to improve the quality of fluorescence labeling for axonal transport analysis in neurons

Abnormal axonal transport of vesicles as well as organelles in a particular set of neurons is implicated in the pathogenesis of many neurodegenerative diseases such as amyotrophic lateral sclerosis, Alzheimer's disease, and Parkinson's disease. Although various types of microfluidic multicompartmental devices with closed microchannels have been recently developed and widely used for axonal transport analysis, most of the existing devices are troublesome and time-consuming to handle, such as culture maintenances, sample collections, and immunocytochemistry. In this study, we overcome such inherent shortcomings by developing a novel open-type device that enables easy cell maintenance and sample collections. In our device, microgrooves instead of microchannels were directly fabricated on a glass substrate, thereby making possible a high-resolution optical observation. Compared with the conventional closed-type devices, our newly designed device allowed us to efficiently and precisely label the axonal acidic vesicles by fluorescent dyes, facilitating a high-throughput analysis of axonal vesicular transport. The present novel device, as a user-friendly and powerful tool, can be implemented in molecular and cellular pathogenesis studies on neurological diseases.

Mathematical modeling of septic shock based on clinical data

Background

Mathematical models of diseases may provide a unified approach for establishing effective treatment strategies based on fundamental pathophysiology. However, models that are useful for clinical practice must overcome the massive complexity of human physiology and the diversity of patients’ environmental conditions. With the aim of modeling a complex disease, we choose sepsis, which is highly complex, life-threatening systemic disease with high mortality. In particular, we focused on septic shock, a subset of sepsis in which underlying circulatory and cellular/metabolic abnormalities are profound enough to substantially increase mortality. Our model includes cardiovascular, immune, nervous system models and a pharmacological model as submodels and integrates them to create a sepsis model based on pathological facts.

Results

Model validation was done in two steps. First, we established a model for a standard patient in order to confirm the validity of our approach in general aspects. For this, we checked the correspondence between the severity of infection defined in terms of pathogen growth rate and the ease of recovery defined in terms of the intensity of treatment required for recovery. The simulations for a standard patient showed good correspondence. We then applied the same simulations to a patient with heart failure as an underlying disease. The model showed that spontaneous recovery would not occur without treatment, even for a very mild infection. This is consistent with clinical experience.

We next validated the model using clinical data of three sepsis patients. The model parameters were tuned for these patients based on the model for the standard patient used in the first part of the validation. In these cases, the simulations agreed well with clinical data. In fact, only a handful parameters need to be tuned for the simulations to match with the data.

Conclusions

We have constructed a model of septic shock and have shown that it can reproduce well the time courses of treatment and disease progression. Tuning of model parameters for each patient could be easily done. This study demonstrates the feasibility of disease models, suggesting the possibility of clinical use in the prediction of disease progression, decisions on the timing of drug dosages, and the estimation of time of infection.