Toroidal orders and related phenomena in nonmagnetic and magnetic materials.

In this short article, we overview a concept of electronic toroidal multipoles, and their ordering with associated physical properties in non-magnetic and magnetic materials. The toroidal multipoles are introduced as microscopic electronic variables in view of symmetry and connection to Dirac theory. They are classified according to crystallographic and magnetic point groups, which allows us to discuss various possible cross correlations in a transparent and unified manner. The representative examples of toroidal orders and related phenomena, and the mutual relationship between these orders are given, with focusing on monopoles and dipoles. The concept of toroidal multipoles would promote future studies toward observations and identifications of unknown electronic phases and their related physical phenomena. .

Prophylactic endoscopic transpapillary gallbladder stenting to prevent acute cholecystitis induced after metallic stent placement for malignant biliary strictures: a retrospective study, Japan.

Background/Aims: Endoscopic biliary drainage using self-expandable metallic stents (SEMSs) for malignant biliary strictures occasionally induces acute cholecystitis (AC). This study evaluated the efficacy of prophylactic gallbladder stents (GBS) during SEMS placement. Methods: Among 158 patients who underwent SEMS placement for malignant biliary strictures between January 2018 and March 2023, 30 patients who attempted to undergo prophylactic GBS placement before SEMS placement were included. Results: Technical success was achieved in 21 cases (70.0%). The mean diameter of the cystic duct was more significant in the successful cases (6.5 mm vs. 3.7 mm, p<0.05). Adverse events occurred for 7 patients (23.3%: acute pancreatitis in 7; non-obstructive cholangitis in 1; perforation of the cystic duct in 1 with an overlap), all of which improved with conservative treatment. No patients developed AC when the GBS placement was successful, whereas 25 of the 128 patients (19.5%) without a prophylactic GBS developed AC during the median follow-up period of 357 days (p=0.043). In the multivariable analysis, GBS placement was a significant factor in preventing AC (hazard ratio, 0.61; 95% confidence interval, 0.37-0.99; p=0.045). Conclusions: GBS may contribute to the prevention of AC after SEMS placement for malignant biliary strictures.

Plain computed tomography for differentiating neoplastic and non-neoplastic pedunculated gallbladder polyps.

AIMS: Surgery is recommended for large pedunculated gallbladder polyps (PGPs), which measure 10 mm or more in size, because they tend to be neoplastic polyps (NPs), such as adenomas and adenocarcinomas. However, after resection, they are often found to be non-neoplastic polyps (non-NPs). This study aimed to evaluate the usefulness of plain CT in distinguishing NPs from non-NPs. METHODS: Of the 80 patients who underwent cholecystectomy for PGPs ( 10 mm between January 2008 and February 2021, 46 who underwent plain and contrast-enhanced CT (CE-CT) before resection were included in this study. We retrospectively assessed the polyp detection rate (PDR) using CT and calculated the difference in the CT values between PGPs and the surrounding bile. RESULTS: Twenty-one patients had NPs (12 adenomas, 5 carcinomas in adenoma, and 4 adenocarcinomas). The others were non-NPs (24 cholesterol polyps and one hyperplastic polyp). The PDR using plain CT was significantly higher in the NP group than in the non-NP group (38% (8/21) vs. 0% (0/25), p <0.01). The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of NPs were 38%, 100%, 100%, 66%, and 72%, respectively. The difference in the CT values between PGPs and the surrounding bile was significantly larger in the NP group than in the non-NP group (14.12 ± 11.38 HU, 5.04 ± 6.15 HU, p <0.01). CONCLUSIONS: PGPs detected using plain CT had a high probability of being NPs. Plain CT is therefore considered to be useful for differentiating NPs from non-NPs.

Pancreatic ductal adenocarcinomas concomitant with intraductal papillary mucinous neoplasms of the pancreas: A investigation of those clinicopathological features by analyzing 48 patients who underwent surgery for those lesions.

BACKGROUND: Differences between pancreatic ductal adenocarcinomas (PDACs) concomitant with intraductal papillary mucinous neoplasm (IPMN) (C-PDACs), those without IPMN (NC-PDACs) and invasive cancers derived from IPMN (IC-Ds) have not been fully clarified. METHODS: Forty-eight patients with C-PDAC were included to investigate the differences in 1) clinicopathological features and 2) post-operative courses among the three invasive cancer groups. RESULTS: 1) Characteristics of C-PDACs were mostly similar to those of NC-PDACs; whereas, between C-PDACs and IC-Ds, the rate of mucinous carcinoma (2%/25%, p = 0.003) and pathological stage (IA, 15%/36%, p = 0.033; III, 31%/4%, p = 0.015) significantly differed. Most C-PDACs coexisted with small, multifocal IPMNs without mural nodules. 2) Cumulative 5-year recurrence-free survival (RFS) rate related to extra-pancreatic recurrence was significantly worse in C-PDACs than in IC-Ds (35%/69%, p = 0.008) and was not significantly different between C-PDACs and NC-PDACs (35%/18%). This related to intra-pancreatic recurrence tended to be poor in the order of IC-Ds, C-PDACs, and NC-PDACs (69%/82%/93%). CONCLUSIONS: Because characteristics of IPMNs remarkably differed between C-PDACs and IC-Ds, another algorithm specific to the early detection of C-PDACs is necessary. Appropriate post-operative managements according to the two types of recurrences may contribute to the improvement in the prognoses of C-PDACs/IC-Ds.

Pancreatic duct lavage cytology combined with a cell-block method for patients with possible pancreatic ductal adenocarcinomas, including pancreatic carcinoma in situ.

BACKGROUND/AIMS: This study aimed to clarify the efficacy and safety of pancreatic duct lavage cytology combined with a cell-block method (PLC-CB) for possible pancreatic ductal adenocarcinomas (PDACs). METHODS: This study included 41 patients with suspected PDACs who underwent PLC-CB mainly because they were unfit for undergoing endoscopic ultrasonography-guided fine needle aspiration. A 6-Fr double lumen catheter was mainly used to perform PLC-CB. Final diagnoses were obtained from the findings of resected specimens or clinical outcomes during surveillance after PLC-CB. RESULTS: Histocytological evaluations using PLC-CB were performed in 87.8% (36/41) of the patients. For 31 of the 36 patients, final diagnoses (invasive PDAC, 12; pancreatic carcinoma in situ, 5; benignancy, 14) were made, and the remaining five patients were excluded due to lack of surveillance periods after PLC-CB. For 31 patients, the sensitivity, specificity, and accuracy of PLC-CB for detecting malignancy were 94.1%, 100%, and 96.8%, respectively. In addition, they were 87.5%, 100%, and 94.1%, respectively, in 17 patients without pancreatic masses detectable using endoscopic ultrasonography. Four patients developed postprocedural pancreatitis, which improved with conservative therapy. CONCLUSION: PLC-CB has an excellent ability to detect malignancies in patients with possible PDACs, including pancreatic carcinoma in situ.

Diagnostic value of homogenous delayed enhancement in contrast-enhanced computed tomography images and endoscopic ultrasound-guided tissue acquisition for patients with focal autoimmune pancreatitis.

BACKGROUND/AIMS: We aimed to investigate (1) promising clinical findings for the recognition of focal type autoimmune pancreatitis (FAIP) and (2) the impact of endoscopic ultrasound (EUS)-guided tissue acquisition (EUS-TA) on the diagnosis of FAIP. METHODS: Twenty-three patients with FAIP were involved in this study, and 44 patients with resected pancreatic ductal adenocarcinoma (PDAC) were included in the control group. RESULTS: (1) Multivariate analysis revealed that homogeneous delayed enhancement on contrast-enhanced computed tomography was a significant factor indicative of FAIP compared to PDAC (90% vs. 7%, p=0.015). (2) For 13 of 17 FAIP patients (76.5%) who underwent EUS-TA, EUS-TA aided the diagnostic confirmation of AIPs, and only one patient (5.9%) was found to have AIP after surgery. On the other hand, of the six patients who did not undergo EUS-TA, three (50.0%) underwent surgery for pancreatic lesions. CONCLUSION: Homogeneous delayed enhancement on contrast-enhanced computed tomography was the most useful clinical factor for discriminating FAIPs from PDACs. EUS-TA is mandatory for diagnostic confirmation of FAIP lesions and can contribute to a reduction in the rate of unnecessary surgery for patients with FAIP.

Chiral phonons: circularly polarized Raman spectroscopy and ab initio calculations in a chiral crystal tellurium.

Recently, phonons with chirality (chiral phonons) have attracted significant attention. Chiral phonons exhibit angular and pseudoangular momenta. In circularly polarized Raman spectroscopy, the peak split of the Γ 3 mode is detectable along the principal axis of the chiral crystal in the backscattering configuration. In addition, peak splitting occurs when the pseudoangular momenta of the incident and scattered circularly polarized light are reversed. Until now, chiral phonons in binary crystals have been observed, whereas those in unary crystals have not been observed. Here, we observe chiral phonons in a chiral unary crystal Te. The pseudoangular momentum of the phonon is obtained in Te by an ab initio calculation. From this calculation, we verified the conservation law of pseudoangular momentum in Raman scattering. From this conservation law, we determined the handedness of the chiral crystals. We also evaluated the true chirality of the phonons using a measure with symmetry similar to that of an electric toroidal monopole.

Mixed neuroendocrine-non-neuroendocrine neoplasm with mucinous adenocarcinoma and amphicrine carcinoma components in the bile duct: an autopsy case.

We report the first case of bile duct mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN) that had a mucinous carcinoma component. An 88-year-old man with biliary obstruction was diagnosed as having distal bile duct cancer using imaging examinations and endoscopic biopsy. The patient received the best supportive care without surgical resection for 13 months until death. An autopsy revealed a bulky mass involving the distal bile duct and multiple metastases in intra-abdominal lymph nodes, the liver, and the lungs. The primary cancer was microscopically diagnosed as a MiNEN, which consisted of mucinous adenocarcinoma and large cell-type neuroendocrine carcinoma (NEC) components. Metastatic lesions in the liver and lungs were composed of only NEC with rich extracellular mucin without adenocarcinoma cells. Using electron microscopy and immunohistochemistry, it was proved that all NEC cells in both primary and metastatic lesions had amphicrine features. On the basis of pathological findings, we thought that the MiNEN was initially derived from a mucinous adenocarcinoma that dedifferentiated to amphicrine NEC cells with mucin production.

Prospective feasibility study on the efficacy and safety of a novel spiral dilator for endoscopic ultrasound-guided drainage.

Objectives: A difficult step in endoscopic ultrasound (EUS)-guided drainage procedures is dilation of the puncture tract before stent deployment. The efficacy and safety of a novel spiral dilator, Tornus ES, for EUS-guided drainage were investigated in this study. Methods: This study was conducted as a prospective, single-arm, observational study at Sendai City Medical center. Dilation of the puncture tract using a spiral dilator was attempted for all EUS-guided drainage cases. The primary outcome was the technical success rate which was defined as successful stent placement in the puncture tract. Secondary outcomes were the success rate of dilation using a spiral dilator, procedure time, and adverse events related to the procedures. Results: A total of 10 patients were enrolled between January and March 2022. Seven patients underwent EUS-guided biliary drainage (hepaticogastrostomy for six and hepaticojejunostomy for one), and the remaining three patients underwent EUS-guided gallbladder drainage. The technical success rate and the success rate of dilation using a spiral dilator were both 100%. The mean procedure time was 27 min. No adverse events related to the procedure occurred in all cases. Conclusions: Dilation of the puncture tract using a spiral dilator was effective and safe and might make it easier to perform EUS-guided drainage.

Treatment Strategy for Acute Cholecystitis Induced by a Metallic Stent Placed in Malignant Biliary Strictures: Role of Percutaneous Transhepatic Gallbladder Aspiration.

Objective The present study evaluated the strategic role of percutaneous transhepatic gallbladder aspiration (PTGBA) for acute cholecystitis (AC) induced by a metallic stent (MS) placed in a malignant biliary stricture in comparison with percutaneous transhepatic gallbladder drainage (PTGBD). Methods The treatment outcomes for 31 patients who underwent PTGBA as the initial intervention for MS-induced AC were evaluated and compared with those for 12 who underwent PTGBD. Results The technical success rate was 100% for both groups. PTGBA was ineffective for 11 patients, all of whom recovered with additional intervention, whereas PTGBD was effective for all patients except for 1 who died of sepsis (clinical success rate, 65% vs. 90%, p=0.16). Adverse events (AEs) were observed in only 1 case (3%) in the PTGBA group (mild bile peritonitis). Among the clinically effective cases, AC recurred in 20% of the PTGBA group and 33% of the PTGBD group (p=0.72). In the PTGBA group, the clinical success rate was significantly higher for patients without cancer invasion to a feeding artery of the gallbladder than in those with invasion (75% without invasion vs. 29% with invasion; p=0.036). According to the multivariate analysis, this factor was an independent factor for clinical success of PTGBA (odds ratio, 9.27; p=0.040). Conclusion Although the clinical success rate of PTGBA for MS-induced AC was lower than that of PTGBD, PTGBA remains a viable option because of its safety and procedural simplicity, especially for cases without tumor invasion to a feeding artery.

Generalization of microscopic multipoles and cross-correlated phenomena by their orderings.

The generalization of the atomic-scale multipoles is discussed. By introducing the augmented multipoles defined in the hybrid orbitals or in the site/bond-cluster, any of electronic degrees of freedom can be expressed in accordance with the crystallographic point group. These multipoles are useful to describe the cross-correlated phenomena, band-structure deformation, and generation of effective spin-orbit coupling due to antiferromagnetic ordering in a systematic and comprehensive manner. Such a symmetry-adapted multipole basis set could be a promising descriptor for materials design and informatics.

Rotation, Electric-Field Responses, and Absolute Enantioselection in Chiral Crystals.

The microscopic origin of chirality, possible electric-field induced static rotational lattice deformation, and rotation-field induced electric polarization are investigated. By building up a realistic tight-binding model for the elemental Te crystal in terms of a symmetry-adapted basis, we identify the microscopic origin of the chirality and essential couplings among polar and axial vectors with the same time-reversal properties. Based on this microscopic model, we elucidate quantitatively that an interband process, driven by nearest-neighbor spin-dependent imaginary hopping, is the key factor in the electric-field induced rotation and its inverse response. From the symmetry point of view, these couplings and responses are characteristic and common to any chiral material, leading to a possible experimental approach to achieve absolute enantioselection by simultaneously applied electric and rotation fields, or a magnetic field and electric current, and so on, as a conjugate field of the chirality.

Early and long-term clinical outcomes of endoscopic interventions for benign pancreatic duct stricture/obstruction-the possibility of additional clinical effects of endoscopic ultrasonography-guided pancreatic drainage.

OBJECTIVES: For benign pancreatic duct strictures/obstructions (BPDS/O), endoscopic ultrasonography-guided pancreatic drainage (EUS-PD) is performed when endoscopic transpapillary pancreatic drainage (ETPD) fails. We clarified the clinical outcomes for patients with BPDS/O who underwent endoscopic interventions through the era where EUS-PD was available. METHODS: Forty-five patients with BPDS/O who underwent ETPD/EUS-PD were included. We retrospectively investigated overall technical and clinical success rates for endoscopic interventions, adverse events, and clinical outcomes after successful endoscopic interventions. RESULTS: The technical success rates for ETPD and EUS-PD were 77% (35/45) and 80% (8/10), respectively, and the overall technical success rate using two drainage procedures was 91% (41/45). Among the 41 patients who underwent successful endoscopic procedures, the clinical success rates were 97% for the symptomatic patients (35/36). The rates of procedure-related pancreatitis after ETPD and EUS-PD were 13% and 30%, respectively. After successful endoscopic interventions, the cumulative 3-year rate of developing recurrent symptoms/pancreatitis was calculated to be 27%, and only two patients finally needed surgery. Continuous smoking after endoscopic interventions was shown to be a risk factor for developing recurrent symptoms/pancreatitis. CONCLUSIONS: By adding EUS-PD to ETPD, the technical success rate for endoscopic interventions for BPDS/O was more than 90%, and the clinical success rate was nearly 100%. Due to the low rate of surgery after endoscopic interventions, including EUS-PD, for patients with BPDS/O, EUS-PD may contribute to their good clinical courses as a salvage treatment for refractory BPDS/O.

Endoscopic Ultrasonography-guided Fine-needle Aspiration Cytology Combined with a Cell-block Method for Gastrointestinal Subepithelial Lesions.

Objective The diagnostic accuracy of an endoscopic ultrasound-guided fine-needle aspiration cytology/biopsy combined with a cell-block method (FNA-CB) for gastrointestinal subepithelial lesions (GI-SELs) has not been fully studied. Methods A total of 109 patients (with 110 GI-SELs) were evaluated to clarify the rate of obtaining evaluable histology specimens using FNA-CB. In addition, we investigated the following: 1) the accuracy for determining the histology, 2) effects of the number of cell clusters obtained via FNA-CB, 3) correlation of the Ki67 labelling index (Ki67LI) of the gastrointestinal stromal tumor (GIST) lesions between FNA-CB and resected specimens, and 4) clinical courses for patients followed up after FNA-CB. Results Of the 110 GI-SELs for which FNA-CB was performed, 95 (86%) were able to be histologically evaluated using the first FNA-CB. For the 70 resected GI-SELs, the accuracy of FNA-CB to determine histology was 96%, remaining at 90% even when only a few cell clusters were obtained. The concordance rate of the risk-grouping of GIST (high-risk, Ki67LI ≥8; low-risk, <8) between FNA-CB and resected specimens was 84%. Of the 29 patients followed up after the first FNA-CB, 12 with benign GI-SELs determined using the first FNA-CB showed no obvious increases in their GI-SEL sizes. Conclusion Since FNA-CB can be used to determine the histology and reproductive activity of GI-SELs accurately, not only preoperative histological confirmation but also reliable information to determine clinical plans, such as follow-up without surgery or neoadjuvant chemotherapy, can be obtained.

Accurate endoscopic identification of the afferent limb at the Y anastomosis using the fold disruption sign after gastric resection with Roux-en-Y reconstruction.

In patients with Roux-en-Y (RY) reconstruction for gastric resection, the newly defined "fold disruption" (FD) sign can be useful to distinguish the afferent limb from the efferent limb at the Y anastomosis when balloon endoscopy-assisted endoscopic retrograde cholangiopancreatography (BE-ERCP) is performed. The FD sign was defined as endoscopic findings of the internal folds disrupted toward the afferent limb and continued toward the efferent limb at the Y anastomosis. In this prospective observational study, the accuracy of the FD sign was evaluated for those who underwent BE-ERCP after gastric resection with RY reconstruction. Of 28 patients for whom the accuracy could be evaluated among 30 enrolled patients, the afferent limb was identified using the FD sign with 100% accuracy. For the other two patients, the scope could not reach the target lumen due to severe intestinal adhesion in one and reached the target lumen without recognition of the Y anastomosis in the other. There was no patient for whom the FD sign could not be judged for any reason, such as a blurred anastomosis line, unclear folds, sticky discharge and blood coating the surface, when the Y anastomosis was recognized. The FD sign was a highly accurate tool for distinguishing the afferent limb from the efferent limb in patients after gastric resection with RY reconstruction. This study was registered in UMIN (issued ID, UMIN000038326).

Pancreatic Ductal Adenocarcinoma Concomitant with Main Duct Type Intraductal Papillary Mucinous Neoplasm of the Pancreas: A Case Report.

BACKGROUND Intraductal papillary mucinous neoplasm of the pancreas (IPMN) and pancreatic ductal adenocarcinoma (PDAC) often coexist in the same pancreas. Almost all IPMNs involving PDACs concomitant with IPMN have been shown to be branch duct type IPMNs (BD-IPMNs), and their histological subtypes are gastric type. Therefore, PDACs concomitant with main duct type IPMNs (MD-IPMNs) are considered to be rare. We herein report a rare case preoperatively diagnosed as being a PDAC concomitant with MD-IPMN on the basis of imaging findings and histological findings of pancreatic specimens endoscopically obtained from 2 lesions. CASE REPORT A 67-year-old man was referred to our hospital due to an enlarged pancreas. Using imaging studies, a solid mass was found in the pancreatic head and intraductal papillary masses in the dilated main pancreatic duct of the body and tail with a fistula in the duodenum. On the basis of histological results using specimens endoscopically obtained from each of the 2 lesions, total pancreatectomy was planned due to suspected PDAC concomitant with an MD-IPMN. Finally, resected specimens were used to confirm the presence of a rare case of PDAC concomitant with MD-IPMN. CONCLUSIONS We encountered a rare case of a PDAC concomitant with an MD-IPMN which could be preoperatively diagnosed by using imaging studies and histological specimens endoscopically obtained. In addition to invasive cancers derived from IPMNs, PDACs concomitant with IPMNs can rarely develop in the pancreas involving MD-IPMNs.

Endoscopic Interventions for the Early and Remission Phases of Acute Biliary Pancreatitis: What are the More Concrete and Practical Situations for Performing Them?

BACKGROUND/AIMS: The use of endoscopic intervention (EI) for acute biliary pancreatitis (ABP) remains controversial because the severity of biliary obstruction/cholangitis/pancreatitis is not reflected in the indications for early EI (EEI). METHODS: A total of 148 patients with ABP were included to investigate 1) the differences in the rate of worsening cholangitis/pancreatitis between the EEI group and the early conservative management (ECM) group, especially for each severity of cholangitis/pancreatitis, and 2) the diagnostic ability of imaging studies, including endoscopic ultrasound (EUS), to detect common bile duct stones (CBDSs) in the ECM group. RESULTS: No differences were observed in the rate of worsening cholangitis between the EEI and ECM groups, regardless of the severity of cholangitis and/or the existence of impacted CBDSs. Among patients without impacted CBDSs and moderate/severe cholangitis, worsening pancreatitis was significantly more frequent in the EEI group (18% vs. 4%, p=0.048). In patients in the ECM group, the sensitivity and specificity for detecting CBDSs were 73% and 98%, respectively, for EUS, whereas the values were 13% and 92%, respectively, for magnetic resonance cholangiopancreatography. CONCLUSION: EEI should be avoided in the absence of moderate/severe cholangitis and/or impacted CBDSs because of the high rate of worsening pancreatitis. EUS can contribute to the accurate detection of residual CBDSs, for the determination of the need for elective EI.

Safety and Recipient Satisfaction of Propofol Sedation in Outpatient Endoscopy: A 24-Hour Prospective Investigation Using a Questionnaire Survey.

BACKGROUND/AIMS: The aim of this study was to evaluate the safety of sedation with propofol as an alternative to benzodiazepine drugs in outpatient endoscopy. METHODS: In this prospective study, examinees who underwent outpatient endoscopy under propofol sedation and submitted a nextday questionnaire with providing informed consent were evaluated. Periprocedural acute responses, late adverse events within 24 hours, and examinee satisfaction were evaluated. RESULTS: Among the 4,122 patients who received propofol in the 17,978 outpatient-based endoscopic examinations performed between November 2016 and March 2018, 2,305 eligible examinees (esophagogastroduodenoscopy for 1,340, endoscopic ultrasonography for 945, and total colonoscopy for 20) were enrolled, and their responses to a questionnaire were analyzed. The mean propofol dose was 69.6±24.4 mg (range, 20-200 mg). Diazepam, midazolam, and/or pentazocine in combination with propofol was administered to 146 examinees. Mild oxygen desaturation was observed in 59 examinees (2.6%); and mild bradycardia, in 2 (0.09%). Other severe reactions or late events did not occur. After eliminating 181 invalid responses, 97.7% (2,065/2,124) of the patients desired propofol sedation in future examinations. CONCLUSION: Propofol sedation was found to be safe-without severe adverse events or accidents-for outpatient endoscopy on the basis of the patients' next-day self-evaluation. Given the high satisfaction level, propofol sedation might be an ideal tool for painless endoscopic screening.