A Novel Hemostatic Peptide Solution for Common Acute Gastrointestinal Bleeding Diseases: First Case Series Study on the Treatment Results of Endoscopic Hemostasis by Nonexpert Endoscopists.

INTRODUCTION: We investigated the hemostatic effect and safety of a hemostatic peptide solution for the treatment of gastrointestinal bleeding requiring emergency endoscopy. METHODS: We retrospectively examined the patient backgrounds, hemostatic results, and procedural safety in patients who were treated with a hemostatic peptide solution for hemostasis during emergency endoscopies for gastrointestinal bleeding. All hemostatic procedures were performed by nonexpert physicians with less than 10 years of endoscopic experience. All of the cases were treated at a single institution over the months from January 2022 to January 2023. RESULTS: Twenty-six consecutive patients (17 males and 9 females) with a median age of 74 (45-95) years were included. Their conditions requiring emergency endoscopy were melena in 8 patients, hematochezia in 2, hematemesis in 8, anemia in 6, and bleeding during esophagogastroduodenoscopy in 2. The sites of bleeding were the esophagus in 3 patients, the stomach in 17, the duodenum in 3, the small intestine in 2, and the colon in 1. Hemostasis was obtained with another hemostasis device used in conjunction with the hemostatic peptide solution in 13 cases and with the hemostatic peptide solution alone in 13 cases. The hemostasis success rate was 100%, with no complications. Rebleeding occurred within 1 week in 4 cases. CONCLUSION: Hemostasis with the hemostatic peptide solution was safe and provided a temporary high hemostatic effect in emergency gastrointestinal endoscopy.

Learning curve for peroral endoscopic myotomy in therapeutic endoscopy experts and nonexperts: Large single-center experience.

OBJECTIVES: Reports on learning curve for peroral endoscopic myotomy (POEM) in therapeutic endoscopy nonexperts are limited. We aimed to assess the number of cases required to achieve POEM proficiency for endoscopic submucosal dissection (ESD) experts and nonexperts. METHODS: This is a retrospective study at the largest POEM referral center in Japan. POEM between April 2014 and December 2020 were included. Nonexperts and ESD experts were divided by training phases: A, 1-20; B, 21-40; C, 41-60; D, 61-80; and E, 81-100 cases. Primary outcome was operation time, and the phase to reach target time (83 min) was investigated. Secondary outcomes were clinical success rate, adverse events, and post-POEM gastroesophageal reflux disease (GERD). RESULTS: Five hundred and sixty-six cases were performed by 14 nonexperts, and 555 cases by 15 ESD experts. As the primary outcome, operation time in nonexperts was: A, 95 (79-115.8); B, 86.5 (71-105); C, 80 (70-100); D, 73 (64.5-100.5); and E, 73.5 (57.8-88.8) min, while in ESD experts: A, 90 (74-128); B, 77 (70-92); and C, 77 (70-93.5) min (median [interquartile range]). Operation time decreased significantly as experience increased in both groups (P < 0.001), and nonexperts required 41-60 cases to achieve proficiency, while experts required 21-40 cases. As secondary outcomes, in nonexperts, clinical success was 96.9-100%, adverse events were 5.0-9.2%, symptomatic GERD was 11.8-26.5%, and proton pump inhibitor (PPI) intake was 11.5-18.7% in each phase. While in experts, clinical success was 96.2-100%, adverse events were 3.0-5.8%, symptomatic GERD was 14.6-22.0%, and PPI intake was 12.6-17.9%. There were no significant differences among training phases. CONCLUSIONS: Non-ESD experts require more cases to achieve proficiency in POEM. These results are useful for establishing POEM training programs and institutional implementation of the procedure.

Novel modified side-by-side balloon dilatation method for esophagogastric junction strictures: Single-/double-barrel techniques.

Endoscopic balloon dilatation is an established treatment for benign gastrointestinal strictures. In order to dilatate safely, it is necessary to dilatate gradually and preferably under direct endoscopic visualization. However, it is currently difficult to achieve dilatation widths of 20-30 mm with commercial products and of over 30-mm with endoscopic visualization. Therefore, a safe and innovative application technique is needed for patients who need these 20-mm or greater dilatation widths. We have developed two methods that enable more than 20-mm dilatation under direct visualization. (i) Single-barrel method: an endoscopic balloon dilatation catheter was fixed with grasping forceps at the tip of the endoscope and carried into the stomach. The balloon catheter was released from the endoscope to create a retroflexed view. The endoscope and balloon were positioned adjacent to each other at the gastric cardia. The balloon was inflated gradually and the esophagogastric junction was dilatated under direct visualization. (ii) Double-barrel method: the same procedure was repeated with two balloons. Theoretically, we achieved a dilatation of >30-mm in diameter. These modified methods may be helpful for esophagogastric junction strictures, such as esophageal achalasia (serving as an initial endoscopic balloon dilatation prior to using a 30-mm achalasia balloon), or for functional strictures after Nissen fundoplication. In conclusion, our simple, modified method enables safe and gradual dilatation under direct endoscopic visualization. Additionally, combination of the sizes of one or two balloons can achieve various widths of dilatation.

Self-adaptive control of infrared emissivity in a solution-processed plasmonic structure.

Active control of optical properties, particularly in the infrared (IR) regime, is critical for the regulation of thermal emission. However, most photonic structures and devices are based on a sophisticated design, making the dynamic control of their IR properties challenging. Here, we demonstrate self-adaptive control of IR absorptivity/emissivity in a simple stacked structure that consists of an oxide plasmonic nanocrystal layer and a phase change material (VO2) layer, both fabricated via a solution process. The resonance wavelength and emission intensity for this structure depend on the phase of the VO2. This has potential applications for thermal emission structures (e.g., self-adaptive radiative cooling and IR camouflage). The proposed structure is a candidate low-cost and scalable active photonic platform.

Self-adaptive radiative cooling based on phase change materials.

With the ability of harvesting the coldness of universe as a thermodynamic resource, radiative cooling technology is important for a broad range of applications such as passive building cooling, refrigeration, and renewable energy harvesting. However, all existing radiative cooling technologies utilize static structures, which lack the ability of self-adaptive tuning based on demand. Here we present the concept of self-adaptive radiative cooling based on phase change materials such as vanadium dioxide. We design a photonic structure that can adaptively turn 'on' and 'off' radiative cooling, depending the ambient temperature, without any extra energy input for switching. Our results here lead to new functionalities of radiative cooling and can potentially be used in a wide range of applications for the thermal managements of buildings, vehicles and textiles.

Effects of Tissue Component Volumes on Vascular Resistance in Free Flaps.

Background A successful free flap transfer is achieved, in part, by having a thorough understanding of vascular anatomy and blood flow dynamics. We previously reported that vascular resistance differs by type of free flap. To test the hypothesis that the difference reflects the proportion of tissue components within free flaps, we calculated blood flow and vascular resistance for free flaps in which we determined the volume of each tissue component. Methods Measurements and calculations were made for 40 free flap transfers performed at our hospital: 7 radial forearm flaps, 14 anterolateral thigh flaps, and 19 rectus abdominis myocutaneous flaps. Results The vascular resistance of free flaps was inversely related to the volume of each tissue component. Univariate regression analysis revealed that muscle volume correlated most closely with resistance (r = 0.881), followed by skin (r = 0.622), and fat (r = 0.577). Multiple regression analysis confirmed the relationship between combined muscle and fat volume and resistance (R2 = 0.865). Conclusions A strong inverse correlation exists between vascular resistance and combined muscle and fat tissue volume in flaps. It may be helpful to consider these relationships when making decisions regarding choice of free flap and recipient vessels.

Upper thoracic empyema and concomitant superior vena cava syndrome treated with reconstructive surgery using a pedicled omental flap.

Superior vena cava (SVC) syndrome refers to a constellation of symptoms secondary to obstruction of blood flow through the SVC. In this condition, venous blood that usually drains into the SVC is diverted into the inferior vena cava (IVC) via collateral veins. Reconstructive surgery is challenging in such cases owing to the anomalous venous system. In this case report, we describe reconstructive surgery using a pedicled omental flap in a patient with upper thoracic empyema and concomitant SVC syndrome. A 68-year-old man underwent resection of malignant thymoma, the bilateral brachiocephalic veins, and a part of the right upper lobe, followed by polytetrafluoroethylene (PTFE) graft placement for venous system reconstruction, 2 years prior to presentation. He developed postoperative upper thoracic cavity empyema, which necessitated PTFE graft removal. Although the infection was controlled after 2 months, multiple right upper lobe pulmonary fistulas persisted, and the patient was referred to our department for further evaluation. Contrast-enhanced computed tomography revealed SVC syndrome characterized by SVC obstruction and consequent drainage of venous blood from the upper trunk into the IVC via collateral vessels. We debrided necrotic and infected tissues, and a pedicled omental flap was placed for upper lobe fistula coverage. The patient showed an uncomplicated postoperative course, and no recurrent empyema or pulmonary fistulas were observed 3 years postoperatively. Flaps associated with the SVC system show high venous pressures. The use of a pedicled omental flap was deemed feasible because this graft reaches the upper thorax even though it is associated with the IVC system.

Per-oral endoscopic myotomy as treatment for Killian-Jamieson diverticulum.

Killian-Jamieson diverticulum (KJD) is a rare type of esophageal diverticulum less commonly encountered compared with Zenker's diverticulum (ZD). Endoscopic approach for these diverticula has been rapidly evolving. Currently, a flexible endoscopic septum division is considered the first-line treatment for symptomatic ZD patients, however reported recurrence rates are over 10% according to recent literature. With the advent of submucosal tunneling technique established by per-oral endoscopic myotomy for achalasia, it has been applied to treat ZD named as Zenker's diverticulum per-oral endoscopic myotomy (Z-POEM) as a minimally invasive treatment. Although there are very few reports utilizing submucosal tunneling approach to KJD, we have opted to perform Z-POEM in order to safely perform complete dissection of the muscle septum while maintaining mucosal integration. Due to the difficulty of anatomical location of KJD, we created mucosal incision and subsequent submucosal tunnel directly at the level of the septum as opposed to creating a submucosal tunnel few centimeters proximal to the septum as being previously proposed. We report a case in which this technique was successfully performed with complete resolution of dysphagia without any adverse event. This technique permits to perform complete myotomies without the fear of causing perforation. Although larger cohorts are required to assess its safety and efficacy, Z-POEM to treat KJD seems to be promising.

Treatment of achalasia with peroral endoscopic myotomy in situs inversus totalis.

Peroral endoscopic myotomy (POEM) has become established as a safe, effective, and versatile minimally invasive endoscopic treatment for achalasia and other esophageal motility disorders. Situs inversus totalis is a rare congenital disorder characterized by a completely reversed position (mirror-image) of the thoracic and abdominal visceral organs. This case report demonstrated a successful treatment of achalasia in a situs inversus totalis by POEM. Similar to the POEM procedure in a normal patient, it is important to maintain the orientation throughout the submucosal tunneling while keeping in mind the reversed orientation and anatomical landmarks. The submucosal tunnel and myotomy were created by an anterior approach which is in this case located at the reversed axis, at 10 o'clock position. There were no major technical modifications needed to be carried out by the operator. No adverse events were noted. Improvement in the Eckardt Symptom Score as well as the barium esophagogram and high-resolution manometry findings on 2-month follow-up exhibited that although POEM was performed in a reversed orientation, similar effects and outcomes were achieved, indicating a successful procedure in this case. In summary, by keeping in mind the reversed positioning and anatomical landmarks in situs inversus totalis, POEM shows to be a safe, effective, and versatile intervention in treating achalasia in situs inversus totalis without the need for major modifications in the procedural technique.

Association between endoscopic pressure study integrated system (EPSIS) and high-resolution manometry.

Background and study aims The endoscopic pressure study integrated system (EPSIS), a novel diagnostic tool for gastroesophageal reflux disease (GERD), allows evaluation of the anti-reflux barrier using endoscopy by monitoring the intragastric pressure (IGP) during insufflation. In this study, we evaluated the association between EPSIS results and lower esophageal sphincter (LES) function measured by high-resolution manometry (HRM) to elucidate whether EPSIS can evaluate the LES function. Patients and methods A retrospective, single-center study of patients with GERD symptoms who underwent endoscopy, pH-impedance monitoring, EPSIS, and HRM was conducted. The primary outcome was basal LES pressure and the secondary outcomes were end-respiratory LES pressure and integrated relaxation pressure (IRP). As EPSIS parameters, the following were measured: 1) pressure difference (mmHg), the difference between maximum and basal IGP; and 2) pressure gradient (mmHg/s), calculated by dividing pressure difference by the insufflating time. Pressure difference < 4.7 mmHg or pressure gradient < 0.07 mmHg/s was defined as an EPSIS GERD pattern. Results Forty-seven patients (median age: 53 years, 37 female) were analyzed. Pressure difference and pressure gradient significantly correlated with basal LES pressure (ρ = 0.29; P =  0.04 and ρ = 0.29; P =  0.04). Patients with EPSIS GERD pattern showed significantly lower basal LES pressure [13.2 (4.8-26.6) vs 25.3 (10.4-66.7) mmHg, P =  0.002], lower end-respiratory LES pressure [8.5 (1.1-15.9) vs 15.5 (1.9-43.9) mmHg, P =  0.019] and lower IRP [5.9 (1.0-12.0) vs 9.8 (1.3-17.8) mmHg, P =  0.020]. Conclusions This study showed a close association between EPSIS results and LES pressures measured by HRM. This indicates that EPSIS can evaluate the LES function during endoscopy and endorse the role of EPSIS as a diagnostic tool for GERD.

Comparison of scope holding sign on endoscopy and lower esophageal sphincter contraction on high-resolution manometry: A pilot study.

Objectives: Lower esophageal sphincter (LES) plays a key role in gastroesophageal reflux disease (GERD) pathogenesis. In retroflexion and under sufficient insufflation, it can be seen how the lower esophagus grasps the endoscope, which we named scope holding sign (SHS). This study aimed to compare the SHS and LES pressure on high-resolution manometry (HRM), to elucidate whether the sphincter can be visualized endoscopically. Methods: This was a single-center, prospective pilot study. Patients with symptoms of GERD, who underwent endoscopy and HRM between February 2021 and April 2021, were included. A manometry catheter and an ultra-slim endoscope were inserted, and the resting LES pressure was measured. The lower esophagus holding (SHS-positive) and releasing (SHS-negative) the endoscope and catheter were observed. The LES pressures during SHS-positive and SHS-negative were compared. Results: Eleven patients (median age: 57 years; eight men) with normal esophageal motility were analyzed. The median LES pressure in SHS-positive was significantly higher than the resting LES pressure (40.4 [22.9-74.0] vs. 25.9 [2.0-66.7] mm Hg; p = 0.001) and the LES pressure in SHS-negative (4.6 [1.5-9.3]; p = 0.001). Furthermore, the LES pressure in SHS-negative was significantly lower than the resting LES pressure (4.6 [1.5-9.3] vs. 25.9 [2.0-66.7] mm Hg; p = 0.005). Conclusions: This study demonstrated that the SHS parallels LES pressure, indicating that the sphincter can be observed endoscopically. This may enable us to evaluate LES function during endoscopy in patients with GERD, thus, deserving further evaluation in future studies.

L1 Cell adhesion molecule (L1CAM) expression at the cancer invasive front is a novel prognostic marker of pancreatic ductal adenocarcinoma.

BACKGROUND AND OBJECTIVES: Pancreatic ductal adenocarcinoma (PDAC) is one of the most extremely aggressive cancers with a poor prognosis after curative resection. L1 cell adhesion molecule (L1CAM) is a 200-220 kDa type I transmembrane glycoprotein of the immunoglobulin superfamily, which has been shown to affect the prognosis of several cancers. No clinicopathological significance of L1CAM expression has been examined at the invasive front of PDAC. In this study, we examined the relationship between L1CAM expression and clinicopathological features in PDAC by immunohistochemistry. METHODS: One hundred seven surgically resected specimens of PDAC were immunohistochemically examined using a monoclonal antibody against L1CAM. RESULTS: Positive expression of L1CAM was found in 23 of 107 cases with PDAC. In most cases (21/23), L1CAM expression was localized at the invasive front of the tumor tissue. Positive expression of L1CAM was significantly correlated with the histological grade, lymph node involvement, and distant metastasis. In univariate analysis, a positive expression of L1CAM was associated with short overall survival (P = 0.0002), and this was significant in multivariate analysis (P = 0.009). CONCLUSIONS: L1CAM could play an important role in the invasive process in vivo, and is thought to be a good indicator of prognosis in PDAC.

Correlation between blood flow, tissue volume and microvessel density in the flap.

The purpose of this study was to assess the correlation between tissue volume and blood flow of the flap in an animal model. Using animal model, tissue volume can be attenuated, and precise change of blood flow could be evaluated. We further investigate the relationship between blood flow and vascular density in the tissue. In this study, we assessed flap conductance (ml/min/mm Hg) as to evaluate the conductivity of blood flow into the flap. Japanese white rabbit was used (n = 7) for this study. The amount of blood flow of jejunal and latissimus dorsi muscle (LD) flaps was measured while removing the distal portion of the flap sequentially. Conductance at each time was calculated from blood pressure and blood flow volume. The tissue volume at each time was also measured. The correlation between conductance and volume was analyzed using a linear mixed model. Immunohistochemical evaluation of microvessel densities (MVD) in these tissues was also performed for CD31/PECAM1 positive area. Conductance and tissue volume were significantly correlated in both jejunal and LD flaps. As the volume increases by 1 cm3, the conductance increased significantly by 0.012 ml/min/mm Hg in jejunum, and by 0.0047 ml/min/mm Hg in LD. Mean MVD was 1.15 ± 0.52% in the jejunum and 0.37 ± 0.29% in the LD muscle. In this study, we revealed that flap conductance is proportional to volume and proportional constant is different between the type of tissue. It suggests that the difference of MVD creates the unique conductance of each tissue.

Dynamic and Asymmetric Changes of the Microbial Communities after Cohousing in Laboratory Mice.

Horizontal transmission of the microbiota between different individuals is widely used to normalize the microbiota in laboratory mice. However, little is known about the dynamics of microbial communities and the level of microbiota transmission after cohousing. We extensively analyzed the fecal microbiota in Jackson and Taconic C57BL/6 mice to study horizontal transmission after weaning. Changes in the microbiota were clearly detected on day 3, almost plateaued on day 7, and resulted in near-comparable composition by day 28 after cohousing. Notably, the transmission of bacterial species was asymmetric in kinetics and abundance, resulting in a microbiota that is more similar to that of Jackson mice than Taconic. Several operational taxonomic units (OTUs) increased their abundance rapidly after cohousing in Taconic mice whereas several OTUs including two mucus-associated bacteria increased their abundance with delayed kinetics in Jackson mice. These studies provide insight into the dynamics and normalization of the microbiota during horizontal transmission.

Cloning and characterization of liver progenitor cells from the scattered cell clusters in primary culture of porcine livers.

The scattered cell clusters that can differentiate into hepatocytes or biliary epithelial cells have been isolated from primary cultures of adult porcine livers. We have generated 11 clonal cell lines from this system and identified liver progenitor cells (LPCs) among the clonal lines. These clonal lines expressed c-kit, HNF-1, HNF-6, and/or CK19 mRNA. An immunocytochemical study of the clonal lines indicated that clonal line CL-11 expressed liver epithelial cell markers CK14, vimentin, CK18, and BD-1. The expression of albumin and alpha1-antitrypsin (alpha1-AT) mRNA was only upregulated in CL-11 among the clonal lines when they were grown as aggregates. Under these conditions, CL-11 also exhibited ammonia metabolic activity and several indicators that suggest hepatocytic differentiation, including the upregulation of liver-specific genes such as dipeptidyl peptidase IV, CYP1A1, and CYP3A4 mRNA, and the downregulation of biliary cell markers such as gamma-glutamyltrans-peptidase (GGT), CK19, and HNF6 mRNA. After culturing CL-11 in Matrigel, the expression of GGT and HNF6 mRNA was upregulated. These results indicate that CL-11 has dual potential: the ability to differentiate as hepatocytes or as bile duct cells. The isolation of scattered cells could provide a simple method to generate LPC lines from adult livers.

Membranous Nephropathy with an Enhanced Granular Expression of Thrombospondin Type-1 Domain-containing 7A in a Pregnant Woman.

A 30-year-old woman with proteinuria first noted at 26 weeks of gestation was admitted to undergo further evaluation. A renal biopsy revealed membranous nephropathy (MN). There was no evidence of any secondary MN. Prednisolone was initiated 6 months after delivery. Four months later, her urine protein became negative. Enhanced granular staining for thrombospondin type-1 domain-containing 7A (THSD7A) in the glomeruli was retrospectively detected in a biopsy specimen. A literature review revealed that 60% of cases of THSD7A-related MN occurred in women of childbearing age. Therefore, THSD7A-related MN should be considered in female patients presenting with idiopathic MN in childbearing age.

Fast Dissociation and Reduced Auger Recombination of Multiple Excitons in Closely Packed PbS Nanocrystal Thin Films.

Exciton decay dynamics in chemically treated PbS quantum-dot (QD) films have been studied using femtosecond transient-absorption (TA) spectroscopy. In photoconductive QD films, a decay component with a lifetime of a few nanoseconds appeared in the TA signals because of exciton dissociation under weak excitation. Increasing excitation fluence resulted in additional fast-decay components corresponding to the lifetimes of multiple excitons, which decreased with increasing photoconductivity of the closely packed QD films. Auger recombination in photoexcited QDs was suppressed in highly photoconductive films. Our findings clearly show that the carrier transfer between the QDs dominates the lifetimes of single and multiple excitons.

Catalytic Enantioselective Protonation of Lithium Ester Enolates Generated by Conjugate Addition of Arylthiolate to Enoates.

A chiral ligand, a catalytic amount of lithium cation, and no chiral proton source: These are features of the present asymmetric addition-protonation of propenoates with 2-trimethylsilylbenzenethiol. The reaction is catalyzed by a combination of lithium 2-trimethylsilylbenzenethiolate and the chiral ligand 1. Desulfurization of the product affords 2-substituted propanoates with high ee values and without racemization. Furthermore, 1 can be recovered quantitatively for reuse.