Computer-aided polyp detection in gastric gastroscopy has been the subject of research over the past few decades. However, despite significant advances, automatic polyp detection in real time is ...still an unsolved problem. In this paper, we report on a convolutional neural network (CNN) for polyp detection that is constructed based on Single Shot MultiBox Detector (SSD) architecture and which we call SSD for Gastric Polyps (SSD-GPNet). To take full advantages of feature maps' information from the feature pyramid and to acquire higher accuracy, we re-use information that is abandoned by Max-Pooling layers. In other words, we reuse the lost data from the pooling layers and concatenate that data as extra feature maps to contribute to classification and detection. Meanwhile, in the feature pyramid, we concatenate feature maps of the lower layers and feature maps that are deconvolved from upper layers to make explicit relationships between layers and to effectively increase the number of channels. The results show that our enhanced SSD for gastric polyp detection can realize real-time polyp detection with 50 frames per second (FPS) and can improve the mean average precision (mAP) from 88.5% to 90.4%, with only a little loss in time-performance. And the further experiment shows that SSD-GPNet has excellent performance in improving polyp detection recalls over 10% (p = 0.00053), especially in small polyp detection. This can help endoscopic physicians more easily find missed polyps and decrease the gastric polyp miss rate. It may be applicable in daily clinical practice to reduce the burden on physicians.
Platelet-derived growth factor receptor A (PDGFRA) mutations occur in approximately 10–15% of gastrointestinal stromal tumors (GISTs). These tumors with PDGFRA mutations have a different ...pathogenesis, clinical characteristics, and treatment response compared to tumors with receptor tyrosine kinase protein (KIT) mutations (60–70%). Many clinical studies have investigated the use of tyrosine kinase inhibitors mainly in patients with KIT mutations; however, there is a lack of attention to the PDGFRA-mutated molecular subtype. The main effective inhibitors of PDGFRA are ripretinib, avapritinib, and crenolanib, and their mechanisms and efficacy in GIST (as confirmed in clinical trials) are described in this review. Some multi-targeted tyrosine kinase inhibitors with inhibitory effects on this molecular subtype are also introduced and summarized in this paper. This review focuses on PDGFRA-mutated GISTs, introduces their clinical characteristics, downstream molecular signaling pathways, and existing resistance mechanisms. We focus on the most recent literature that describes the development of PDGFRA inhibitors and their use in clinical trials, as well as the potential benefits from different combination therapy strategies.
Background
A Western diet is a risk factor for the development of inflammatory bowel disease (IBD). High levels of fecal deoxycholic acid (DCA) in response to a Western diet contribute to bowel ...inflammatory injury. However, the mechanism of DCA in the natural course of IBD development remains unanswered.
Aims
The aim of this study is to investigate the effect of DCA on the induction of gut dysbiosis and its roles in the development of intestinal inflammation.
Methods
Wild-type C57BL/6J mice were fed an AIN-93G diet, either supplemented with or without 0.2% DCA, and killed at 24 weeks. Distal ileum and colon tissues were assessed by histopathological analysis. Hepatic and ileal gene expression was examined by qPCR, and the gut microbiota was analyzed by high-throughput 16S rRNA gene sequencing. HPLC–MS was used for fecal bile acid quantification.
Results
Mice fed the DCA-supplemented diet developed focal areas of ileal and colonic inflammation, accompanied by alteration of the composition of the intestinal microbiota and accumulation of fecal bile acids. DCA-induced dysbiosis decreased the deconjugation of bile acids, and this regulation was associated with the repressed expression of target genes in the enterohepatic farnesoid X receptor–fibroblast growth factor (FXR–FGF15) axis, leading to upregulation of hepatic de novo bile acid synthesis.
Conclusions
These results suggest that DCA-induced gut dysbiosis may act as a key etiologic factor in intestinal inflammation, associated with bile acid metabolic disturbance and downregulation of the FXR–FGF15 axis.
Gastric precancerous diseases (GPD) may deteriorate into early gastric cancer if misdiagnosed, so it is important to help doctors recognize GPD accurately and quickly. In this paper, we realize the ...classification of 3-class GPD, namely, polyp, erosion, and ulcer using convolutional neural networks (CNN) with a concise model called the Gastric Precancerous Disease Network (GPDNet). GPDNet introduces fire modules from SqueezeNet to reduce the model size and parameters about 10 times while improving speed for quick classification. To maintain classification accuracy with fewer parameters, we propose an innovative method called iterative reinforced learning (IRL). After training GPDNet from scratch, we apply IRL to fine-tune the parameters whose values are close to 0, and then we take the modified model as a pretrained model for the next training. The result shows that IRL can improve the accuracy about 9% after 6 iterations. The final classification accuracy of our GPDNet was 88.90%, which is promising for clinical GPD recognition.
Background and Aims ERCP is recommended for patients considered high risk for choledocholithiasis after biochemical testing and abdominal US. Our aim was to determine whether the American Society for ...Gastrointestinal Endoscopy (ASGE) guidelines accurately select patients for whom the risk of ERCP is justified. Methods Consecutive patients hospitalized with suspected choledocholithiasis at Sir Run Run Shaw Hospital who received biochemical testing, abdominal US, and definitive testing for choledocholithiasis (MRCP, EUS, ERCP, intraoperative cholangiogram, and/or common bile duct CBD exploration) were identified. Patients with choledocholithiasis on abdominal US, with bilirubin levels >4 mg/dL (normal values <1.2 mg/dL), bilirubin levels ≥1.8 mg/dL plus a dilated CBD and/or clinical cholangitis were considered high risk per ASGE guidelines. Results Of 2724 patients with suspected choledocholithiasis, 1171 (43%) met high-risk criteria. Definitive testing (MRCP in 2442 90%, EUS in 67 2%, ERCP in 659 24%, intraoperative cholangiogram in 229 8%, and CBD exploration in 447 16%) revealed choledocholithiasis in 1076 40% patients. The specificity of the ASGE high-risk criteria was 74% (95% confidence interval CI, 72%-77%) and positive predictive value was 64% (95% CI, 61%-67%). Using a more restrictive criteria (choledocholithiasis on abdominal US, bilirubin >4 mg/dL plus dilated CBD) improved the specificity to 94% (95% CI, 93%-95%) and positive predictive value to 85% (95% CI, 82%-88%). Doubling or more of bilirubin to >4 mg/dL and ≥1.8 mg/dL at second testing had specificities of 98% (95% CI, 96%-99%) and 95% (95% CI, 93%-96%), with positive predictive values of 62% (95% CI, 48%-76%) and 54% (95% CI, 44%-65%), respectively. Conclusions Although ASGE high-risk criteria demonstrated >50% probability of the patient having choledocholithiasis, more than a third of the patients would receive diagnostic ERCPs. Criteria with choledocholithiasis on abdominal US and/or bilirubin levels >4 mg/dL plus a dilated CBD showed higher specificity and positive predictive value.
Inflammatory bowel disease (IBD) is associated with gut dysbiosis and dysregulation of bile acid metabolism. A high luminal content of deoxycholic acid (DCA) with consumption of a Westernized diet is ...implicated in the pathogenesis of IBD. The aim of the study is to explore the role of intestinal microbiota and bile acid metabolism in mice with DCA-induced intestinal inflammation.
4-week-old wild-type C57BL mice were fed with AIN-93G (control diet), AIN-93G+0.2% DCA, AIN-93G+0.2% DCA+6 weeks of fexaramine (FXR agonist), or AIN-93G+0.2% DCA+antibiotic cocktail for 24 weeks. Histopathology, Western blotting, and qPCR were performed on the intestinal tissue. Fecal microbiota was analyzed by 16S rDNA sequencing. Fecal bile acid and short-chain fatty acid (SCFA) levels were analyzed by chromatography.
Gut dysbiosis and enlarged bile acid pool were observed in DCA-treated mice, accompanied by a lower farnesoid X receptor (FXR) activity in the intestine. Administration of fexaramine mitigated DCA-induced intestinal injury, restored intestinal FXR activity, activated fibroblast growth factor 15, and normalized bile acid metabolism. Furthermore, fexaramine administration increased the abundance of SCFA-producing bacteria. Depletion of the commensal microbiota with antibiotics decreased the diversity of the intestinal microbiota, attenuated bile acid synthesis, and reduced intestinal inflammation induced by DCA.
DCA induced-intestinal inflammation is associated with alterations of gut microbiota and bile acid profiles. Interventions targeting the gut microbiota-FXR signaling pathway may reduce DCA-induced intestinal disease.
As one of the most common mesenchymal malignancies in the digestive system, gastrointestinal stromal tumors (GISTs) occur throughout the alimentary tract with diversified oncological characteristics. ...With the advent of the tyrosine kinase inhibitor era, the treatment regimens of patients with GISTs have been revolutionized and GISTs have become the paradigm of multidisciplinary therapy. However, surgery resection remains recognized as the potentially curative management for the radical resection and provided with favorable oncological outcomes. The existing available surgery algorithms in clinical practice primarily incorporate open procedure, and endoscopic and laparoscopic surgery together with combined operation techniques. The performance of various surgery methods often refers to the consideration of risk evaluation of recurrence and metastases; the degree of disease progression; size, location, and growth pattern of tumor; general conditions of selected patients; and indications and safety profile of various techniques. In the present review, we summarize the fundamental principle of surgery of GISTs based on risk assessment as well as tumor size, location, and degree of progress with an emphasis on the indications, strengths, and limitations of current surgery techniques.
(HP) infection is closely associated with the development of chronic gastritis, peptic ulcer, and gastric cancer. However, the resistance rate of
strains to antibiotics such as clarithromycin, ...metronidazole, and levofloxacin has increased significantly, resulting in a significant decrease in the eradication efficacy of commonly used regimens. Tetracycline has received the attention of domestic and foreign scholars because of its low resistance. The purpose of this review is to provide an update on the tetracycline-containing bismuth quadruple eradication therapy for
infection and review the efficacy and safety of the regimens, hoping to provide guidance for clinical practice.
Gastroscopy plays an important role in the diagnosis of gastric disease. In this paper, we develop an image panoramic system to assist endoscopists in improving lesion surveillance and reducing many ...of the tedious operations associated with gastroscopy. The constructed panoramic view has two categories: 1) the local view broadens the endoscopist's field of view in real time. Combining with the original gastroscopic video, this mosaicking view enables the endoscopist to diagnose the lesion comprehensively; 2) the global view constructs a large-area panoramic scene of the internal gastric surface, which can be used for intraoperative surgical navigation and postoperative scene review. Due to the irregular texture and inconsistent reflection of the gastric internal surface, common registration methods cannot accurately stitch this surface. Thereby, a six degree of freedom position tracking endoscope is devised to accommodate for the accumulated mosaicking error and provide efficient mosaicking results. For the global view, a dual-cube constraint model and a Bundle Adjustment algorithm are incorporated to deal with the mosaicking error caused by the irregular inflation and nonrigid deformation of the stomach. Moreover, texture blending and frame selection schemes are developed to make the mosaicking results feasible in real-clinical applications. The experimental results demonstrate that our system performs with a speed of 7.12 frames/s in a standard computer environment, and the mosaicking mean error is 0.43 mm for local panoramic view and 3.71 mm for global panoramic view.
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