Orthodontic rubber band traction to facilitate endoscopic resection of gastric submucosal tumor.

BACKGROUND AND STUDY AIMS: Endoscopic submucosal excavation (ESE) and endoscopic full-thickness resection (EFTR) are common endoscopic minimally invasive methods for treatment of gastric submucosal tumors (SMTs). However, it is sometimes difficult to expose the tumor optimally. This study aimed to explore the safety and effectiveness of tumor traction using orthodontic rubber band (ORB) combined with clips to assist ESE and EFTR of gastric SMTs. PATIENTS AND METHODS: The data of patients with gastric SMTs who underwent ESE or EFR at the Endoscopy Center of the 900th Hospital of PLA from January 2021 to May 2022 were retrospectively analyzed. Baseline characteristics and clinical outcomes, including operation time and postoperative adverse events, were compared between patients receiving ORB-ESE/EFTR and conventional ESE/EFTR. RESULTS: A total of 52 patients were enrolled: 16 patients who underwent ORB-ESE /EFTR and 36 patients who underwent conventional ESE/EFTR. Median procedure time was significantly shorter in the ORB-ESE/EFTR group than in the conventional ESE/EFTR group (32 [IQR, 23.8, 38.0] minutes vs. 39.0 [IQR, 34.6-67.3] minutes, P = 0.002). Baseline characteristics, en bloc resection rate, incidence of postoperative adverse events, and postoperative pathology results were comparable between the two groups (P > 0.05). CONCLUSION: Use of ORB with clips-assisted traction during ESE/EFTR of gastric SMT can shorten the surgical time. Further large prospective studies are needed to confirm the findings of this study.

Novel beagle model of gastric local fibrotic target lesions for the evaluation and training of endoscopic techniques.

BACKGROUND: Novel endoscopic techniques used in the treatment of gastric lesions with local submucosal fibrosis need preclinical evaluation and training due to safety limitations. Therefore, the purpose of our study was to establish an animal model of gastric local fibrotic target lesions and assess its feasibility in the evaluation and training of endoscopic techniques. METHODS: In six experimental beagles, a 50% glucose solution was injected into three submucosal areas of the fundus, body, and antrum of the stomach to create gastric local fibrotic target lesions (experimental group). On post-injection day (PID) 7, the injection sites were assessed endoscopically to confirm the presence of submucosal fibrosis formation, and the dental floss clip traction assisted endoscopic submucosal dissection (DFC-ESD) procedure was performed on the gastric local fibrotic target lesions to confirm its feasibility after endoscopic observation. The normal gastric mucosa of six control beagles underwent the same procedure (control group). All the resected specimens were evaluated by histological examination. RESULTS: All 12 beagles survived without postoperative adverse events. On PID 7, 16 ulcer changes were observed at the injection sites (16/18) under the endoscope, and endoscopic ultrasonography confirmed the local submucosal fibrosis formation in all ulcer lesions. The subsequent DFC-ESD was successfully performed on the 32 gastric target lesions, and the mean submucosal dissection time in the ulcer lesions was greater than that in the normal gastric mucosa (15.3 ± 5.6 vs. 6.8 ± 0.8 min; P < 0.001). There was no difference in rates of en bloc resection, severe hemorrhage, or perforation between the two groups. Histological analysis of the ulcer lesions showed the absence of epithelial or muscularis mucosae and extensive submucosal fibrous tissue proliferations compared with normal gastric mucosa. Overall, endoscopists had high satisfaction with the realism and feasibility of the animal model. CONCLUSION: We developed a novel animal model of gastric local fibrotic target lesions to simulate difficult clinical situations, which strongly appeared to be suitable for the preclinical evaluation and learning of advanced endoscopic techniques.

Magnetic ring-assisted endoscopic submucosal dissection for gastric lesions with submucosal fibrosis: A preliminary study in beagle model.

BACKGROUND: During endoscopic submucosal dissection (ESD) for gastric lesions with fibrosis, appropriate traction could provide clear submucosal dissection visualization to improve safety and efficiency of procedures. Therefore, the aim of this study was to evaluate the feasibility of magnetic ring-assisted ESD (MRA-ESD) for gastric fibrotic lesions. METHOD: In the eight healthy beagles, 2-3 mL of 50% glucose solution was injected into submucosal layer of the stomach to induce gastric fibrotic lesions. A week after submucosal injection, two endoscopists at different levels performed MRA-ESD or standard ESD (S-ESD) for gastric simulated lesions, respectively. The magnetic traction system consisted of external handheld magnet and internal magnetic ring. The feasibility and procedure outcomes of the magnetic traction system were mainly evaluated. RESULTS: Forty-eight gastric simulated lesions with ulceration were confirmed to have submucosal fibrosis formation by preoperative endoscopic ultrasonography. The magnetic traction system could be easily established, only took 1.57 min, and allowed excellent submucosal visualization. The total procedure time was significantly shorter in the MRA-ESD group than in the S-ESD group for both endoscopists (mean: 46.83 vs. 25.09 min, p < 0.001), and this difference was accentuated in non-skilled endoscopist. There was significant difference between two groups in bleeding and perforation rates. Histological analysis showed the depth of resected specimens was a little deeper around the fibrotic portion in the S-ESD group (p < 0.001). CONCLUSION: The magnetic ring-assisted ESD technique may be an effective and safe treatment for gastric fibrotic lesions and may shorten the endoscopic learning curve for non-skilled endoscopists.

Experimental Study on Gastric Labeling by Magnetic Detector Combined With Magnetic Bead.

OBJECTIVE: Preoperative labeling of gastric cancer is an important means to determine the surgical margin. At present, there are many commonly used labeling methods. However, which is more accurate and has fewer complications remains to be studied. Through animal experiments, this study explored the feasibility, accuracy, and safety of a magnetic detector combined with magnetic beads for the preoperative labeling of gastric cancer. METHODS: A total of 10 beagle dogs were included in the study. Each dog was randomly labeled with magnetic beads in the gastric body and antrum. After labeling, the magnetic detector was used to explore the gastric serosa surface, and the positioning titanium clip was released at the detected magnetic bead. The main monitoring index was to measure the distance between the labeled magnetic beads and the positioning titanium clamped. The secondary indexes were detection time, magnetic induction intensity, magnetic bead shedding rate, mucosal injury rate, bleeding, and leukocyte and C-reactive protein levels before and 24 hours after the operation. RESULTS: All 10 beagle dogs completed the marking and exploration successfully. The average distance between the magnetic beads and the positioning titanium clip in 20 cases was 5.90±2.36 mm. The average detection time was 1.60±0.69 min, and the average magnetic induction intensity was 3.76±1.11 mT. No magnetic beads were found to fall off, 1 case had a mild mucosal injury, and 2 cases had a small amount of bleeding when releasing the positioning titanium clip. The white blood cells before and 24 hours after the operation were 7.43±0.94(×10 9 /L) versus 7.79±0.67(×10 9 /L) ( P =0.34). The C-reactive protein before and 24 hours after the operation were 5.24±0.97 µg/mL versus 5.95±1.02 µg/mL ( P =0.13). CONCLUSION: A magnetic detector combined with magnetic beads for gastric cancer labeling is feasible, accurate, and safe. It is expected to be further applied in the clinic.

Antimicrobial prophylaxis in patients undergoing endoscopic mucosal resection for 10- to 20-mm colorectal polyps: A randomized prospective study.

BACKGROUND AND PURPOSE: Endoscopic mucosal resection (EMR) is frequently used for the removal of colorectal neoplasms. However, the use of prophylactic antibiotics in patients undergoing EMR is debatable. The aim of this randomized controlled trial was to assess whether antimicrobial prophylaxis is crucial in the perioperative period of EMR, especially for 10- to 20-mm lesions in this setting. METHODS: Two hundred and sixty-four patients were randomized equally into 2 groups, the antibiotic (cefixime) group and the control group. The occurrence of adverse events was examined at 1 to 3 days after EMR. Plasma levels of inflammatory markers were analyzed at pre-operation, 1 day post-operation and 3 days post-operation. Blood samples collected at 1 day post-operation were used for culture. RESULTS: A total of 264 and 268 polyps were removed by EMR in the antibiotic group and the control group, respectively. There were 5 cases of fever, with 2 in the antibiotic group and 3 in the control group. In the antibiotic group, 12 patients had abdominal pain and 10 suffered bleeding, whereas in the control group, abdominal pain and bleeding were observed in 10 and 11 patients, respectively. There were no significant differences in the proportion of patients with fever or the incidences of postoperative complications between the groups. No significant differences between the groups were reported in plasma levels of white blood cell count, erythrocyte sedimentation rate, C-reactive protein or procalcitonin at pre-operation or post-operation. No patients provided positive blood cultures. CONCLUSIONS: The use the prophylactic antibiotics for EMR procedures in the perioperative period is no longer required when the lesions are 10 to 20 mm in size.

Bladder epithelial cell phosphate transporter inhibition protects mice against uropathogenic Escherichia coli infection.

Urinary tract infections are predominantly caused by uropathogenic Escherichia coli (UPEC). UPEC infects bladder epithelial cells (BECs) via fusiform vesicles, escapes into the cytosol to evade exocytosis, and establishes intracellular bacterial communities (IBCs) for the next round of infection. The UPEC vesicle escape mechanism remains unclear. Here we show that UPEC senses host immune responses and initiates escape by upregulating a key phospholipase. The UPEC phospholipase PldA disrupts the vesicle membrane, and pldA expression is activated by phosphate reduction in vesicles. The host phosphate transporter PIT1 is located on the fusiform vesicle membrane, transporting phosphate into the cytosol. UPEC infection upregulates PIT1 via nuclear factor κB (NF-κB), resulting in phosphate reduction. Silencing PIT1 blocks UPEC vesicle escape in BECs, inhibits IBC formation in mouse bladders, and protects mice from UPEC infection. Our results shed light on pathogenic bacteria responding to intracellular phosphate shortage and tackling host defense and provide insights for development of new therapeutic agents to treat UPEC infection.

Transcriptional Activator GmrA, Encoded in Genomic Island OI-29, Controls the Motility of Enterohemorrhagic Escherichia coli O157:H7.

Enterohemorrhagic Escherichia coli O157:H7 is a major human enteric pathogen capable of causing large outbreaks of severe infections that induce bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome. Its genome contains 177 unique O islands (OIs) including those carrying the main virulence elements, Shiga toxin-converting phages (OI-45 and OI-93) and locus for enterocyte effacement (OI-148). However, many of these islands harbor only genes of unknown function. Here, we demonstrate that OI-29 encodes a newly discovered transcriptional activator, Z0639 (named GmrA), that is required for motility and flagellar synthesis in O157:H7. GmrA directly binds to the promoter of fliA, an RNA polymerase sigma factor, and thereby regulates flagellar genes controlled by FliA. Expression of gmrA is maximal under host conditions (37°C, neutral pH, and physiological osmolarity), and in the presence of host epithelial cells, indicative of a role of this gene in infection by promoting motility. Finally, GmrA was found to be a widespread regulator of bacterial motility and flagellar synthesis in different pathotypes of E. coli. Our work largely enriches our understanding of bacterial motility control, and provides another example of regulators acquired laterally that mediate flagellar synthesis.