The nature of interactions of phenol with various molecules (Y = HF, HCl, H2O, H2S, NH3, PH3, MeOH, MeSH) is investigated using ab initio calculations. The optimized geometrical parameters and spectra for the global energy minima of the complexes match the available experimental data. The contribution of attractive (electrostatic, inductive, dispersive) and repulsive (exchange) components to the binding energy is analyzed. HF favors sigma O-type H-bonding, while H2O, NH3, and MeOH favor sigma H-type H-bonding, where sigma O-/sigma H-type is the case when a H-bond forms between the phenolic O/H atom and its interacting molecule. On the other hand, HCl, H2S, and PH3 favor pi-type H-bonding, which are slightly favored over sigma O-, sigma H-, sigma H-type bonding, respectively. MeSH favors chi H-type bonding, which has characteristics of both pi and sigma H. The origin of these conformational preferences depending on the type of molecules is elucidated. Finally, phenol-Y complexes are compared with water-Y complexes. In the water-Y complexes where sigma O/sigma H-type involves the H-bond by the water O/H atom, HF and HCl favor sigma O-type, H2O involves both sigma O-/sigma H-type, and H2S, NH3, PH3, MeOH, and MeSH favor sigma H-type bonding. Except for HF, seven other species have larger binding energies with a phenol molecule than a water molecule.

Background and Aims Gastric mucosal swab may be a more sensitive sampling method than a biopsy since Helicobacter pylori (H. pylori) resides within the mucus layer. We compared the diagnostic performance of the rapid urease test (RUT) and bacterial load of H. pylori between swabs and tissue biopsy. Methods Overall, 276 RUTs (138 swab‐RUTs (S‐RUT) and 138 tissue‐RUTs (T‐RUT)) were performed. To diagnose H. pylori infection, RUT, H. pylori PCR, and 16S ribosomal RNA gene sequencing of tissue and swab were used, and its infection was defined as at least two positives of the six test results. The diagnostic performances of RUTs and the H. pylori bacterial load using qPCR were compared between swab and biopsy. Results The positivity rates of S‐RUT and T‐RUT were 35.5% (49/138) and 25.4% (35/138), respectively. The sensitivity, specificity, and accuracy of S‐RUT were 98.0%, 100.0%, and 99.2%, while those of T‐RUT were 70.0%, 100%, and 89.1%, respectively. The sensitivity and accuracy were significantly higher for S‐RUT than for T‐RUT (p < 0.05). In the patients with atrophic gastritis and intestinal metaplasia, S‐RUT showed significantly higher sensitivity than T‐RUT. qPCR showed that the swab contained a significantly higher H. pylori bacterial load than tissue biopsy (22.92‐fold and 31.61‐fold in the antrum and body (p < 0.05), respectively). Conclusions Gastric mucosal swabs showed higher RUT accuracy and H. pylori bacterial load than a tissue biopsy. This may be an alternative to a biopsy when diagnosing H. pylori infection during endoscopy is necessary. (http://clinicaltrials.gov, NCT05349578).

No abstract

No abstract

Background: Lymphovascular invasion is a criterion for noncurative resection in patients who have undergone endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). We aimed to determine the rate of extragastric metastasis (EGM) and identify predictors of EGM in patients with negative resected margins (R0 resection) and lymphovascular invasion in their post-ESD pathology.Methods: Among 2,983 consecutive patients, 110 were treated with ESD with follow-up pathology of R0 resection and lymphovascular invasion. Patients received additional gastrectomy (n=63) or further follow-up without gastrectomy (n=47).Results: The 110 patients were assigned to one of three groups according to ESD indications based on post-ESD pathology. Group 1 satisfied the absolute indication of ESD (n=18), group 2 satisfied the expanded indication of ESD (n=34), and group 3 was beyond indication (n=58). The number of occurrences of EGM in each group was 1 (5.6%), 3 (8.8%), and 3 (5.2%), respectively. The logistic regression analysis, which adjusted for age, sex, tumor size, and indication of ESD, showed that larger tumor size was associated with EGM (odds ratio 1.76, 95% confidence interval 1.00–3.10, p=0.048). By contrast, ESD indication criteria did not affect EGM (p=0.349).Conclusions: Tumor size was the only predictive indicator for EGM in patients with R0 resection and lymphovascular invasion in their post-ESD pathology. Even patients with pathology corresponding to the absolute indication criteria of ESD had lymphovascular invasion, which means they require an additional gastrectomy due to the risk of EGM.