Endoscopic treatment of bile duct stones with benign choledochojejunal anastomotic stenosis.

[BACKGROUND AND AIMS]: Endoscopic interventions for bile duct stones (BDS) with benign choledochojejunal anastomotic stenosis (bCJS) are challenging. Therefore, we investigated endoscopic interventions for BDS with bCJS. [METHODS]: Seventeen patients with BDS with bCJS were retrospectively analyzed. Patient characteristics, technical success, adverse events (AEs), and recurrence were evaluated. [RESULTS]: In 17 patients, the median diameters of the bile duct and BDS were both 8 mm. The median number of BDS was 3. The technical success rate was 94% (16/17). Ten patients underwent balloon dilation at the choledochojejunal anastomotic site (CAS), the median diameter of balloon dilation was 10.5 mm, and waist disappearance was achieved in 2. Six patients had fully covered self-expandable metal stents (FCSEMS) with a diameter of 10 mm placed at the CAS. BDS were removed after balloon dilation or FCSEMS removal, and 6 out of 16 patients were treated with a combination of lithotripsy and 5 with peroral direct cholangioscopy (PDCS). Regarding AEs, perforation at the CAS by balloon dilation occurred in 1 patient. The median follow-up was 3701 days. Nine out of 16 patients (56%) had recurrence. The patients treated with combination of PDCS at BDS removal (p=0.022) and waist disappearance at the CAS by balloon dilation (p=0.035) had significantly fewer recurrences. [CONCLUSIONS]: Endoscopic interventions for BDS with bCJS are useful and relatively safe; however, long-term follow-ups showed frequent recurrences. Recurrence was common in patients not treated with the combination of PDCS at BDS removal and those without waist disappearance at the CAS by balloon dilation.

Bile duct MALT lymphoma diagnosed with direct cholangioscopy: a case report.

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) extremely rarely arise in extrahepatic biliary tract. Here, we report a case of bile duct MALT lymphoma diagnosed with direct cholangioscopy. The patient was an 80-year-old female with history of esophageal cancer, and had been occasionally treated with balloon dilatation for anastomotic stricture. She was referred to our hospital for treatment of choledocholithiasis. Since transesophageal endoscope insertion was impossible, stone extraction by transjejunal approach was performed. When gastroduodenoscope was directly inserted to the bile duct (direct cholangioscopy), accidentally two flat lesions with development of large atypical vessels in hilar region were noted. Biopsy revealed diffuse infiltration of CD20 positive small- to medium-sized atypical lymphocytes. A diagnosis of bile duct MALT lymphoma was made. The patient underwent eight courses of chemotherapy with rituximab alone, with no evident complications. Although biliary tract MALT lymphoma is rare, advances in cholangioscopy may promote encounter with such lesions. Accumulation of endoscopic figures of biliary tract MALT lymphoma is required.

Biliary stones or ulcers at the choledochojejunal anastomotic site involving the jejunal mucosa at stent removal may be recurrent factors in patients with benign choledochojejunal anastomotic stenosis undergoing endoscopic biliary stenting using fully covered self-expandable metal stents.

BACKGROUND: Temporary fully covered self-expandable metal stent (FCSEMS) placement is performed for benign choledochojejunal anastomotic stenosis (bCJS). However, recurrence may develop after stricture resolution. We investigated endoscopic biliary stenting using FCSEMS for bCJS. METHODS: Sixteen bCJS patients with FCSEMS placement were retrospectively analyzed. FCSEMS was removed endoscopically after 2 months. Technical success, stricture resolution, recurrence, and adverse events were evaluated. RESULTS: The technical success rate for FCSEMS placement was 94% (15/16). Biliary stones were detected and extracted in four patients. FCSEMS removal was successfully performed on 14 patients, excluding one with stent migration. At FCSEMS removal, stricture resolution was noted in 14 patients; however, four had anastomotic ulcers. The median follow-up was 319 days. Three patients with a history of repeated plastic stent placement had no recurrence. Four out of 15 patients (27%) had recurrence, and three had no recurrence after additional interventions. Biliary stones before first FCSEMS placement (P = .003) or anastomotic ulcers at FCSEMS removal (P = .018) were associated with recurrence. CONCLUSIONS: Although FCSEMS placement was useful for stricture resolution, recurrence was detected in patients with biliary stones before first FCSEMS placement or anastomotic ulcers at FCSEMS removal. Anastomotic ulcers are a risk factor for recurrence and only detected by endoscopy.

Large anomalous Nernst effect and nodal plane in an iron-based kagome ferromagnet.

Anomalous Nernst effect (ANE), converting a heat flow to transverse electric voltage, originates from the Berry phase of electronic wave function near the Fermi energy EF. Thus, the ANE provides a sensitive probe to detect a topological state that produces large Berry curvature. In addition, a magnet that exhibits a large ANE using low-cost and safe elements will be useful to develop a novel energy harvesting technology. Here, we report our observation of a high ANE exceeding 3 microvolts per kelvin above room temperature in the kagome ferromagnet Fe3Sn with the Curie temperature of 760 kelvin. Our theoretical analysis clarifies that a "nodal plane" produces a flat hexagonal frame with strongly enhanced Berry curvature, resulting in the large ANE. Our discovery of the large ANE in Fe3Sn opens the path for the previously unexplored functionality of flat degenerate electronic states and for developing flexible film thermopile and heat current sensors.

[A case of pancreatic actinomycosis diagnosed by EUS-FNA].

A 60-year-old male patient had alcoholic chronic pancreatitis. Three months prior, he had undergone an exchange of pancreatic duct stents. In December 201X-1, magnetic resonance imaging and computed tomography (CT) scan results showed a caput pancreatic mass and common bile duct dilatation. We considered that it was because of chronic pancreatitis and decided to follow up by imaging studies. Further, in March 201X, a CT scan result revealed worsening of the mass and bile duct dilation. We assessed the mass by endoscopic ultrasound and fine-needle aspiration. Histological findings revealed to an interstitial tissue infiltrated by several neutrophils and plasma cells and abscess-forming inflammation like sulfur granule. The mass was improved by antibiotic administration for 6 months.

The characteristics of the immune cell profiles in peripheral blood in cholangiocarcinoma patients.

BACKGROUND: Immune related cells are known to be closely related to the therapeutic effects and prognoses of cancer patients. In this study, we analyzed immune cell profiles (ICP) of cholangiocarcinoma patients (CCA). METHODS: To measure the frequency of immune cells, peripheral blood mononuclear cells of 41 CCA and 10 healthy volunteers (HV) were analyzed by FACS. RESULTS: There were significant differences between CCA and HV in ICP, and these differences were a consequence of tumor-bearing status, because many items in ICP before surgery were restored to levels in HV after surgery. Therefore, these changes were specifically attributable to cholangiocarcinoma, and we examined if they can function as biomarkers for therapeutic effects and prognoses. A shorter overall survival was associated with a lower frequency of helper T cells (HT) (p = 0.001), a higher frequency of effector regulatory T cells (eTregs) (p = 0.008), and a lower frequency of CD80 + eTregs (p = 0.024) in the best supportive care group, with a lower frequency of CD25 + naïve Tregs (nTregs) (p = 0.005) in the chemotherapy group, and with a lower frequency of OX40 + HT (p = 0.022), CD25 + CD8 + T cells (p = 0.017), and OX40 + CD8 + T cells (p = 0.032) in the surgery group. The recurrence factors were a higher frequency of CD4 + T cells (p = 0.009), CCR6 + nTregs (p = 0.014), and CXCR3 + nTregs (p = 0.012), and a lower frequency of PD-1 + HT (p = 0.006), OX40 + HT (p = 0.004), CD8 + T cells (p = 0.001), and CTLA-4 + CD8 + T cells (p = 0.036). CONCLUSIONS: The ICP in CCA are specifically attributable to cholangiocarcinoma, and may be biomarkers for therapeutic effects and prognoses.

Long-term outcomes after endoscopic retrograde pancreatic drainage for symptomatic pancreaticojejunal anastomotic stenosis.

There is limited evidence supporting the usefulness of endoscopic retrograde pancreatic drainage (ERPD) for symptomatic pancreaticojejunal anastomotic stenosis (sPJS). We examined the usefulness of ERPD for sPJS. We conducted a retrospective analysis of 10 benign sPJS patients. A forward-viewing endoscope was used in all sessions. Following items were evaluated: technical success, adverse events, and clinical outcome of ERPD. The technical success rate was 100% (10/10) in initial ERPD; 9 patients had a pancreatic stent (no-internal-flap: n = 4, internal-flap: n = 5). The median follow-up was 920 days. Four patients developed recurrence. Among them, 3 had a stent with no-internal-flap in initial ERPD, the stent migrated in 3 at recurrence, and a stent was not placed in 1 patient in initial ERPD. Four follow-up interventions were performed. No recurrence was observed in 6 patients. None of the stents migrated (no-internal-flap: n = 1, internal-flap: n = 5) and no stents were replaced due to stent failure. Stenting with no-internal-flap was associated with recurrence (p = 0.042). Mild adverse events developed in 14.3% (2/14). In conclusions, ERPD was performed safely with high technical success. Recurrence was common after stenting with no-internal-flap. Long-term stenting did not result in stent failure.Clinical trial register and their clinical registration number: Nos. 58-115 and R2-9.

Bipolar-current needle-knife with a water jet function (Jet B-knife) shortens the procedure time of endoscopic submucosal dissection for colorectal tumors.

BACKGROUND: Endoscopic submucosal dissection (ESD) is a technically difficult and time-consuming procedure for the treatment of large colorectal tumors. In Japan, the ball-tip bipolar-current needle-knife (BB-knife) has been used in ESD as a safe device that minimizes the damage to deeper tissues of colorectal neoplasms. In May 2012, a BB-knife combined with a water jet function (Jet B-knife) was newly developed. METHODS: This retrospective study was aimed at examining the effectiveness and safety of the Jet B-knife. The BB-knife was used in 276 lesions (BB-knife group), while the Jet B-knife was used in 245 lesions (Jet B-knife group). We evaluated tumor characteristics and the results of the ESD procedures, including the size of the resected tumor, histological diagnosis, time required for resection, frequency of using other electrical devices, en bloc resection rate, and incidence rate of associated complications. Then, the data obtained were compared between the two groups. RESULTS: The histological evaluation of the resected tumors revealed that the incidence of cancer was not significantly different between the two groups. The median time required for resection was 103 min (45-255) in the BB-knife group and 51 min (28-210) in the Jet B-knife group. The difference was statistically significant (p < 0.05). Furthermore, the median tumor diameters were 23.1 mm (18-50) and 26.2 mm (20-60) in the BB-knife and Jet B-knife groups, respectively, demonstrating a statistically significant difference (p < 0.05). Multivariate logistic regression analysis revealed that short resection time (p < 0.001) and reduced use of hemostatic devices (p < 0.01) were independent favorable features of Jet B-knife. The en bloc resection rate and the perforation rate were not statistically significant between the two groups. CONCLUSIONS: Use of the Jet B-knife may contribute to the development of a time-saving, cost-effective, and safe procedure for ESD of colorectal tumors.

Author Correction: Iron-based binary ferromagnets for transverse thermoelectric conversion.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Electrical manipulation of a topological antiferromagnetic state.

Electrical manipulation of phenomena generated by nontrivial band topology is essential for the development of next-generation technology using topological protection. A Weyl semimetal is a three-dimensional gapless system that hosts Weyl fermions as low-energy quasiparticles1-4. It has various exotic properties, such as a large anomalous Hall effect (AHE) and chiral anomaly, which are robust owing to the topologically protected Weyl nodes1-16. To manipulate such phenomena, a magnetic version of Weyl semimetals would be useful for controlling the locations of Weyl nodes in the Brillouin zone. Moreover, electrical manipulation of antiferromagnetic Weyl metals would facilitate the use of antiferromagnetic spintronics to realize high-density devices with ultrafast operation17,18. However, electrical control of a Weyl metal has not yet been reported. Here we demonstrate the electrical switching of a topological antiferromagnetic state and its detection by the AHE at room temperature in a polycrystalline thin film19 of the antiferromagnetic Weyl metal Mn3Sn9,10,12,20, which exhibits zero-field AHE. Using bilayer devices composed of Mn3Sn and nonmagnetic metals, we find that an electrical current density of about 1010 to 1011 amperes per square metre induces magnetic switching in the nonmagnetic metals, with a large change in Hall voltage. In addition, the current polarity along the bias field and the sign of the spin Hall angle of the nonmagnetic metals-positive for Pt (ref. 21), close to 0 for Cu and negative for W (ref. 22)-determines the sign of the Hall voltage. Notably, the electrical switching in the antiferromagnet is achieved with the same protocol as that used for ferromagnetic metals23,24. Our results may lead to further scientific and technological advances in topological magnetism and antiferromagnetic spintronics.

Iron-based binary ferromagnets for transverse thermoelectric conversion.

Thermoelectric generation using the anomalous Nernst effect (ANE) has great potential for application in energy harvesting technology because the transverse geometry of the Nernst effect should enable efficient, large-area and flexible coverage of a heat source. For such applications to be viable, substantial improvements will be necessary not only for their performance but also for the associated material costs, safety and stability. In terms of the electronic structure, the anomalous Nernst effect (ANE) originates from the Berry curvature of the conduction electrons near the Fermi energy1,2. To design a large Berry curvature, several approaches have been considered using nodal points and lines in momentum space3-10. Here we perform a high-throughput computational search and find that 25 percent doping of aluminium and gallium in alpha iron, a naturally abundant and low-cost element, dramatically enhances the ANE by a factor of more than ten, reaching about 4 and 6 microvolts per kelvin at room temperature, respectively, close to the highest value reported so far. The comparison between experiment and theory indicates that the Fermi energy tuning to the nodal web-a flat band structure made of interconnected nodal lines-is the key for the strong enhancement in the transverse thermoelectric coefficient, reaching a value of about 5 amperes per kelvin per metre with a logarithmic temperature dependence. We have also succeeded in fabricating thin films that exhibit a large ANE at zero field, which could be suitable for designing low-cost, flexible microelectronic thermoelectric generators11-13.

Successful biliary self-expandable metallic stenting using an ultra-slim endoscope for cholangitis caused by pancreatic cancer.

Highlight Kida and colleagues described their method for successfully performing biliary self-expandable metallic stenting with the through-the-scope technique using an ultra-slim endoscope for malignant biliary obstruction with duodenal stenosis. This procedure may be useful in cases of duodenal stenosis in which it is difficult to reach the major duodenal papilla.

Usefulness of endoscopic metal stent placement for malignant afferent loop obstruction.

BACKGROUND: Malignant afferent loop obstruction (mALO) can cause cholangitis, pancreatitis, and perforation due to blind loop dilatation. However, peritoneal dissemination, lymph node metastasis, and recurrence of the tumor are the main causes of mALO, and most cases are in the advanced stage with thoracicoabdominal fluid retention, for which surgery and percutaneous transhepatic treatment are challenging. At our hospital, endoscopic metal stent placement (EMSP) has been applied for such mALO. We retrospectively investigated the usefulness of EMSP for mALO. METHODS: We conducted a retrospective analysis of 11 mALO patients with EMSP between January 2008 and December 2018. The following items were evaluated: the characteristics of patients, technical success and adverse events of EMSP, clinical efficacy, and outcome after EMSP. RESULTS: The surgical procedures and reconstruction methods were distal gastrectomy with Billroth II reconstruction for 3 patients, pancreaticoduodenectomy with modified-Child reconstruction for 7, choledochojejunostomy with Roux-en-Y reconstruction for 1. The cause of mALO was peritoneal dissemination for 6 patients, local recurrence for 3, lymph node metastasis for 1, and afferent loop invasion for 1. EMSP was attempted in 13 sessions for 11 patients, and successful in 12 of 13 sessions. There were no adverse events. The clinical efficacy was high in successful EMSP. The median survival time after EMSP was 118 days. Ten patients died of primary disease and one patient died of uncontrollable cholangitis after the failure of EMSP. mALO recurred and EMSP was repeated for 2 of 10 patients who died of primary disease. CONCLUSIONS: The success rate of EMSP for mALO was high in patients with poor general conditions due to advanced-stage malignant tumors and it was able to be safely performed, suggesting its high clinical efficacy. The incidence of mALO recurrence after EMSP was low.

Unveiling hidden multipolar orders with magnetostriction.

Broken symmetries in solids involving higher order multipolar degrees of freedom are historically referred to as "hidden orders" due to the formidable task of detecting them with conventional probes. In this work, we theoretically propose that magnetostriction provides a powerful and novel tool to directly detect higher-order multipolar symmetry breaking-such as the elusive octupolar order-by examining scaling behaviour of length change with respect to an applied magnetic field h. Employing a symmetry-based Landau theory, we focus on the family of Pr-based cage compounds with strongly correlated f-electrons, Pr(Ti,V,Ir)2(Al,Zn)20, whose low energy degrees of freedom are purely higher-order multipoles: quadrupoles [Formula: see text] and octupole [Formula: see text]. We demonstrate that a magnetic field along the [111] direction induces a distinct linear-in-h length change below the octupolar ordering temperature. The resulting "magnetostriction coefficient" is directly proportional to the octupolar order parameter, thus providing clear access to such subtle order parameters.

Giant Anisotropic Magnetoresistance due to Purely Orbital Rearrangement in the Quadrupolar Heavy Fermion Superconductor PrV_{2}Al_{20}.

We report the discovery of giant and anisotropic magnetoresistance due to the orbital rearrangement in a non magnetic correlated metal. In particular, we measured the magnetoresistance under fields up to 31.4 T in the cubic Pr-based heavy fermion superconductor PrV_{2}Al_{20} with a non magnetic Γ_{3} doublet ground state, exhibiting antiferroquadrupole ordering below 0.7 K. For the [100] direction, we find that the high-field phase appears between 12 and 25 T, accompanied by a large jump at 12 T in the magnetoresistance (ΔMR∼100%) and in the anisotropic magnetoresistivity ratio by ∼20%. These observations indicate that the strong hybridization between the conduction electrons and anisotropic quadrupole moments leads to the Fermi surface reconstruction upon crossing the field-induced antiferroquadrupole (orbital) rearrangement.

Phase II clinical trial of second-line weekly paclitaxel plus trastuzumab for patients with HER2-positive metastatic gastric cancer.

BACKGROUND: Combination therapy with fluorouracil, platinum, and trastuzumab (Tmab) is the first-line treatment for human epidermal growth factor receptor 2 (HER2)-positive gastric cancer, and there is currently no established second-line therapy. We evaluated the efficacy and safety of weekly paclitaxel plus Tmab as second-line chemotherapy for HER2-positive gastric cancer patients. PATIENTS AND METHODS: Eligible patients were older than or equal to 20 years, had histologically confirmed gastric adenocarcinoma that was HER2 positive (immunohistochemistry 3+ or immunohistochemistry 2+ and fluorescence in-situ hybridization positive or dual color in-situ hybridization positive), and had been treated previously with chemotherapy (pretreated or not with Tmab). Patients received weekly paclitaxel plus Tmab as the second-line chemotherapy. The primary endpoint was the overall response rate (ORR; threshold ORR=20% and expected ORR=35%). RESULTS: Twenty-eight patients were enrolled. ORR was 21.4%. The median progression-free survival (PFS) was 4.6 months. The median overall survival (OS) was 9.6 months. No significant differences were observed in ORR, PFS, or OS between the Tmab beyond progression (TBP) group (n=20) and the non-TBP group (n=8). However, in the TBP group, a therapeutic effect was associated with the duration of PFS in the first-line Tmab treatment [≥6 months PFS in the first-line Tmab treatment (n=10) vs. <6 months (n=10); ORR: 40 and 10%, P=0.303, PFS: 6.2 and 2.8 months, P=0.005, OS: 15.8 and 6.5 months, P=0.006, respectively]. CONCLUSION: Weekly paclitaxel plus Tmab was not superior as second-line chemotherapy for HER2-positive gastric cancer patients, but may be effective for patients who showed better responses to Tmab-combined chemotherapy in the first-line treatment.