Novel endoscopic duodenal observation protocol based on Seven Pictures Rule for detecting duodenal neoplasms during esophagogastroduodenoscopy: Prospective observational study.

OBJECTIVES: No protocol for esophagogastroduodenoscopic examination of the duodenum has been established. We examined the feasibility and ability to detect neoplasms of a novel duodenal examination protocol. METHODS: This was a two-facility, prospective, observational study. Our protocol, the Seven Pictures Rule (7PR), requires pictures of the following seven locations: anterior and posterior to the bulb, area of and contralateral to the superior duodenal angle, area of and contralateral to the ampulla, and the transverse duodenum. The primary outcome was rate of completion of 7PR. Secondary outcomes were overall rates of detecting neoplasms, rates of detecting neoplasms for each location, examination time, and completion rates for standard or ultrathin endoscopes. RESULTS: There were 1549 participants. The 7PR completion rate was 81.1% and the detection rates of overall neoplasms, adenomas, and carcinomas were 0.84%, 0.71%, and 0.06%, respectively. The area in which most neoplasms was detected was contralateral to the ampulla (69.2%), and the fewest the transverse duodenum (0%). Mean duration of duodenal examination was 53.1 s. Completion rates for standard vs. ultrathin were 84.4% (1077/1276) vs. 65.6% (179/273) (P < 0.01), respectively. CONCLUSIONS: Seven Pictures Rule is acceptable for duodenal examination and a potential quality indicator.

A geminal theory based on the generalized electron pairing.

As in the hierarchy of the Hartree-Fock theory in terms of spin symmetry, the extension of spin functions in a theory of two-electron units or geminal, was developed in this study. A trial wave function is constructed as an antisymmetrized product of geminals, in which singlet and triplet two-electron functions are fully mixed. We present a variational optimization method for this generalized pairing wave function in the strong orthogonality condition. The present method is considered an extension of the antisymmetrized product of strongly orthogonal geminals or perfect pairing generalized valence bond methods, maintaining the compactness of the trial wave function. The obtained broken-symmetry solutions were similar to the unrestricted Hartree-Fock wave functions in terms of spin contamination while giving lower energy due to the inclusion of the electron correlation effect in geminals. The degeneracy of the obtained broken-symmetry solutions in the Sz space is reported for the tested four-electron systems.

Comparison of purse-string suture versus over-the-scope clip for gastric endoscopic full-thickness closure: traction and leak pressure testing in ex vivo porcine model.

BACKGROUND: The recently developed endoscopic full-thickness resection technique requires reliable closure. The main closure methods are the purse-string suture (PSS) technique and over-the-scope clip (OTSC) technique; however, basic data on the closure strength of each technique are lacking. This study was performed to compare the closure strengths of these two methods in an ex vivo porcine model. METHODS: In the traction test, a virtual 5-cm full-thickness closure line was closed by the following six methods three times each: conventional hemoclips, mucosal PSS, seromuscular PSS, mucosal OTSC, seromuscular OTSC, and surgical suture. The primary endpoint was the tension at the starting point of dehiscence, measured in Newtons (N) by an automatic traction machine. In the leak test, a 15-mm gastric full-thickness defect was closed by PSS or OTSC six times each, and the closed stomach was then pressurized in a water container. The primary endpoint was the leak pressure when air bubbles appeared. The secondary endpoints were the procedure time and presence of complete inverted closure. RESULTS: The mean tension was 2.16, 3.68, 5.15, 18.30, 19.30, and 62.40 N for conventional hemoclips, mucosal PSS, seromuscular PSS, mucosal OTSC, seromuscular OTSC, and surgical suture, respectively. Complete inverted closure was observed for seromuscular PSS, seromuscular OTSC, and surgical suture. The mean leak pressure was 13.7 and 24.8 mmHg in the PSS and OTSC group, respectively (P < 0.01). The mean procedure time was 541 and 169 s in the PSS and OTSC group, respectively (P < 0.01). Complete inverted closure was observed in OTSC alone. CONCLUSION: The OTSC, which allows complete inverted closure, showed greater closure strength than PSS. Considering the size limitation suitable for single OTSC, a therapeutic strategy for closing the larger size is further warranted.

A catalyzed E/Z isomerization mechanism of stilbene using para-benzoquinone as a triplet sensitizer.

Sensitizer molecules affect not only the quantum yield but also the selectivity of photochemical reactions. For an appropriate design of sensitized photochemical processes, we need to elucidate the reaction mechanism in detail. Here we investigated the mechanism of photoisomerization of stilbene via the triplet state with a para-benzoquinone sensitizer using density functional theory. In general, the isomerization of stilbene via the triplet state exhibits (Z)-selectivity (cis-selectivity); however, the para-benzoquinone sensitizer changes it to (E)-selectivity (trans-selectivity). The calculations showed that stilbene and para-benzoquinone form stable exciplexes having a preoxetane structure. The E/Z isomerization occurred via this exciplex, in which para-benzoquinone acted as a photocatalyst rather than a sensitizer only providing excitation energy. The spin-density distribution of the exciplex differed from the isolated stilbene in the triplet state. Therefore, the stilbene moiety could take (E)-conformation in the exciplex. The intermolecular charge-transfer drove the exciplex formation. This specific reaction mechanism originated from the electron-accepting ability of para-benzoquinone in the triplet state.

Solvation in nitration of benzene and the valence electronic structure of the Wheland intermediate.

Nitration of benzene is a representative aromatic substitution reaction related to the σ-complex (arenium ion or "Wheland" intermediate) concept. This reaction is typically carried out in a mixed acid solution to generate nitronium ions, and how solvent molecules play roles in the reaction has been of great interest. Here we will shed new light on the reaction, namely the electronic structure and the microscopic insights of the solvation, which have been rarely discussed so far. We studied this process using the reference interaction site model-self consistent field with constrained spatial electron density distribution (RISM-SCF-cSED) method, considering sulfuric acid or water molecules as a solvent. In this method, the electronic structure of the solute and the solvation structure are self-consistently determined based on quantum chemistry and statistical mechanics of molecular liquids. The solvation free energy surfaces in solution and solvation structures were verified. In the bond formation process of benzene and nitronium ions, the solvation structure by sulfuric acid molecules drastically changes and the solvation effect on the free energy is quite large. We revealed largely contributing resonance structures in the π-electron system of the σ-complex in gas and solution phases by analysing the valence electronic structures.

Extraction of local spin-coupled states by second quantized operators.

We present a methodology for analyzing chemical bonds embedded in the electronic wave function of molecules, especially in terms of spin correlations or so-called "local spin." In this paper, based on biorthogonal second quantization, the spin correlation functions of molecules are naturally introduced, which enables us to extract local singlet and local triplet elements from the wave function. We also clarify the relationship between these spin correlations and traditional chemical concepts, i.e., resonance structures. Several chemical reactions, including the intramolecular radical cyclization and the formation of preoxetane, are demonstrated to verify the analysis method numerically.

An analysis of valence electronic structure from a viewpoint of resonance theory: Tautomerization of formamide and diazadiboretidine.

The resonance theory is still very useful in understanding the valence electron structure. However, such a viewpoint is not usually obtained by general-purpose quantum chemical calculations, instead requires rather special treatment such as valence bond methods. In this study, we propose a method based on second quantization to analyze the results obtained by general-purpose quantum chemical calculations from the local point of view of electronic structure and analyze diazadiboretidine and the tautomerization of formamide. This method requires only the "PS"-matrix, consisting of the density matrix (P-matrix) and overlap matrix, and can be computed with a comparable load to that of Mulliken population analysis. A key feature of the method is that, unlike other methods proposed so far, it makes direct use of the results of general-purpose quantum chemical calculations.

Effective and Secure Closure after Duodenal Endoscopic Submucosal Dissection: Combination of Endoscopic Ligation with O-Ring Closure and Over-the-Scope Clip.

Duodenal endoscopic submucosal dissection (ESD) is associated with high incidences of intraoperative complications and delayed adverse events (AEs). Delayed AEs can be reduced by closing the post-ESD defects. We developed a new method of closure after duodenal ESD, combining endoscopic ligation with O-ring closure (E-LOC) with an over-the-scope clip (OTSC) (Band OTSC; B-OTSC). Here, we conducted a single-center, retrospective, observational study to investigate the efficacy and safety of the B-OTSC method for preventing delayed AEs in patients undergoing duodenal ESD. The study included nine patients with superficial nonpapillary duodenal epithelial tumors who underwent ESD and were closed with B-OTSC from February 2021 to February 2023. There were no delayed AEs (0%), the mean (± standard deviation) closure time was 53 ± 21.6 min, the complete closure rate was 100%, and the mean hospital stay was 7.8 ± 1.8 days. The sustained closure rates at postoperative days 3 and 7 were 88.9% and 88.9%, respectively. The historical analysis indicated a significant difference in cost between B-OTSC and conventional OTSC (p < 0.01). In conclusion, B-OTSC was a safe, secure, and cost-effective method of closure after duodenal ESD, even in patients with post-ESD defects of more than half the circumference.

Comparison of Needle Knife versus Scissors Forceps for Colorectal Endoscopic Submucosal Dissection: A Prospective Randomized Study.

BACKGROUND AND AIM: To evaluate the efficacy and safety of a grasping-type knife, called Clutch Cutter (CC), for colorectal endoscopic submucosal dissection (C-ESD). METHODS: This was a randomized prospective study. Patients who underwent C-ESD for colorectal neoplasms >20 mm and <50 mm in size were enrolled, dividing into two groups: ESD using needle type of dual knife alone (D-group) and circumferential incision using dual knife followed by submucosal dissection using CC (CC-group). The primary outcome was the self-completion rate. The secondary outcomes were intraoperative complication rate, procedure time, and en bloc resection rate. RESULTS: A total of 45 patients were allocated to the D-group and 43 to the CC-group were allocated. The self-completion rate was higher in the CC-group (87% [39/45] vs. 98% [42/43]). All of the six patients with an incomplete procedure in the D-group were completely resected with CC use. The intraoperative complication rate was not significant in either group (D vs. CC: 2% vs. 0%). The mean procedure time was significantly shorter in the D-group than that in the CC-group (62.0 vs. 81.1 min; p = 0.0036). The en bloc resection rate was 100% in the D-group and 98% in the CC-group. CONCLUSIONS: While dual knife use is superior to CC in terms of time efficiency, the use of CC may be a safe and efficacious option for achieving complete C-ESD.

Acceptability of Hybrid Endoscopic Submucosal Dissection Using Multifunctional Snare for Small-sized Gastric Neoplasms: A Prospective Observational Study.

BACKGROUND AND AIMS: The most suitable procedure for resecting small-sized gastric neoplasms remains unclear. Endoscopic mucosal resection leads to non-curative resection owing to slippage of the snare, and technically difficult endoscopic submucosal dissection (ESD) is instrumentally uneconomical. A novel, cost-effective, multifunctional snare called SOUTEN is available as a hybrid ESD (h-ESD) device developed for facilitating ESD. This study aimed to assess the acceptability of h-ESD using the SOUTEN for resecting small-sized gastric neoplasms. METHODS: This was a prospective observational study conducted at our single institution between March 2019 and March 2021. Fifty-seven consecutive patients who underwent h-ESD using SOUTEN for small-sized gastric neoplasms ≤15 mm involving adenoma and tubular-type mucosal carcinoma without ulceration were enrolled. The primary outcome was curative resection rate for h-ESD. Secondary outcomes were the rates of conversion to ESD, rate of total (h-ESD + ESD) curative resection, procedure time, rates of intra-and post- operative complications, and presence of additional knives excluding hemostatic forceps. RESULTS: The curative resection rate of h-ESD was 89.5% (51/57). The total (h-ESD + ESD) curative resection rate was 94.7% (54/57). The mean procedure time was 21.2 (±16.5) minutes. One case of delayed bleeding occurred. Additional knives were applied in two cases. CONCLUSIONS: The cost-efficient h-ESD using SOUTEN can be an acceptable procedure for resecting small- sized gastric neoplasms.

White Spot, a Novel Endoscopic Finding, May Be Associated with Acid-Suppressing Agents and Hypergastrinemia.

White globe appearance (WGA) is defined as a microendoscopic white lesion with a globular shape underlying the gastric epithelium and is considered a marker of gastric cancer. We recently reported that endoscopically visualized white spot (WS) corresponding to WGA appeared on the nonatrophic mucosa of patients with acid-suppressing agents (A-SA) use. We evaluated patients undergoing routine esophagogastroduodenoscopy and divided the patients into an A-SA group (n = 112) and a control group (n = 158). We compared the presence of WS in both groups. We also compared WS-positive- (n = 31) and -negative (n = 43) groups within the A-SA group regarding these patients' backgrounds and serum gastrin concentrations. Comparing the A-SA group with controls, the prevalence of WS was significantly higher (31/112 vs. 2/158; p < 0.001). The number of patients with high serum gastrin concentrations was significantly higher in the WS-positive group (18/31) vs. the WS-negative group (5/43) (p < 0.001). Within the A-SA group, the prevalence of WS was also significantly higher in patients taking potassium-competitive acid blockers vs. proton-pump inhibitors (21/31 vs. 10/31, p < 0.001). The WS-positive group had a significantly greater percentage of patients, with a high serum gastrin level (p < 0.001). WS may be associated with hypergastrinemia and potassium-competitive acid blockers.