Sonic hedgehog expression in a rat model of chronic pancreatitis

AIM:To analyze the activation of sonic hedgehog(SHh)signaling pathways in a rat model of chronic pancreatitis.METHODS:Forty Wistar rats were randomly divided into 2 groups:experimental group and control group(20rats in each group).Dibutyltin dichloride was infused into the tail vein of the rats to induce chronic pancreatitis in the experimental group.The same volume of ethanol and glycerol mixture was infused in the control group.The expression of Ptch,Smo and Gli were analyzed using immunohistochemistry,and real-time reverse transcription polymerase chain reaction(RT-PCR).RESULTS:Compared with the control group,significant histological changes in terms of the areas of abnormal architecture,glandular atrophy,fibrosis,pseudo tubular complexes,and edema were observed at week 4 in the experimental group.The expression of Ptch1,Smo and Gli1 in the pancreatic tissue increased significantly in the experimental group.Using RT-PCR,mRNA levels of Ptch,Smo and Gli in the experimental group increased significantly compared with the control group.CONCLUSION:The SHh signaling pathway is aberrantly activated in rats with chronic pancreatitis.The SHh signaling pathway plays an important role in the development of chronic pancreatitis.These results may be helpful in studies focusing on the relationship between chronic pancreatitis and pancreatic cancer.

Establishing a model to measure and predict the quality of gastrointestinal endoscopy

BACKGROUND Tens of millions of gastrointestinal endoscopic procedures are performed every year in China,but the quality varies significantly and related factors are complex.Individual endoscopist-and endoscopy division-related factors may be useful to establish a model to measure and predict the quality of endoscopy.AIM To establish a model to measure and predict the quality of gastrointestinal endoscopic procedures in China's Mainland.METHODS Selected data on endoscopy experience,equipment,facility,qualification of endoscopists,and other relevant variables were collected from the National Database of Digestive Endoscopy of China.The multivariable logistic regression analysis was used to identify the potential predictive variables for occurrence of medical malpractice and patient disturbance.Linear and nonlinear regressions were used to establish models to predict incidence of endoscopic complications.RESULTS In 2012,gastroscopy/colonoscopy-related complications in China's Mainland included bleeding in 4,359 cases(0.02%)and perforation in 914(0.003%).Endoscopic-retrograde-cholangiopancreatography-related complications included severe acute pancreatitis in 593 cases(0.3%),bleeding in 2,151(1.10%),perforation in 257(0.13%)and biliary infection in 4,125(2.11%).Moreover,1,313(5.0%)endoscopists encountered with medical malpractice,and 5,243(20.0%)encountered with the disturbance from patients.The length of endoscopy experience,weekly working hours,weekly night shifts,annual vacation days and job satisfaction were predictors for the occurrence of medical malpractice and patient disturbance.However,the length of endoscopy experience and the ratio of endoscopists to nurses were not adequate to establish an effective predictive model for endoscopy complications.CONCLUSION The workload and job satisfaction of endoscopists are valuable predictors for medical malpractice or patient disturbance.More comprehensive data are needed to establish quality-predictive models for endoscopic complications.

Application of an artificial intelligence system for endoscopic diagnosis of superficial esophageal squamous cell carcinoma

BACKGROUND Upper gastrointestinal endoscopy is critical for esophageal squamous cell carcinoma(ESCC)detection;however,endoscopists require long-term training to avoid missing superficial lesions.AIM To develop a deep learning computer-assisted diagnosis(CAD)system for endoscopic detection of superficial ESCC and investigate its application value.METHODS We configured the CAD system for white-light and narrow-band imaging modes based on the YOLO v5 algorithm.A total of 4447 images from 837 patients and 1695 images from 323 patients were included in the training and testing datasets,respectively.Two experts and two non-expert endoscopists reviewed the testing dataset independently and with computer assistance.The diagnostic performance was evaluated in terms of the area under the receiver operating characteristic curve,accuracy,sensitivity,and specificity.RESULTS The area under the receiver operating characteristics curve,accuracy,sensitivity,and specificity of the CAD system were 0.982[95%confidence interval(CI):0.969-0.994],92.9%(95%CI:89.5%-95.2%),91.9%(95%CI:87.4%-94.9%),and 94.7%(95%CI:89.0%-97.6%),respectively.The accuracy of CAD was significantly higher than that of non-expert endoscopists(78.3%,P<0.001 compared with CAD)and comparable to that of expert endoscopists(91.0%,P=0.129 compared with CAD).After referring to the CAD results,the accuracy of the non-expert endoscopists significantly improved(88.2%vs 78.3%,P<0.001).Lesions with Paris classification type 0-IIb were more likely to be inaccurately identified by the CAD system.CONCLUSION The diagnostic performance of the CAD system is promising and may assist in improving detectability,particularly for inexperienced endoscopists.

Photodynamic therapy of cancer-Challenges of multidrug resistance

Photodynamic therapy(PDT)of cancer is a two-step drug device combination modality,which involves the topical or systemie administration of a photosensitizer followed by light ilumnination of cancer site.In the presence of oxygen molecules,the light illmnination of photosensitizer(PS)can lead to the generation of cytotoxic reactive oxygen species(ROS)and consequently destroy cancer.Similar to many other anticancer therapies,PDT is also subject to intrinsic cancer resistance mediated by mutidrug resistance(MDR)mechanisms.This paper will review the recent progress in understanding the interaction between MDR transporters and PS uptalke.The strategies that can be used in a clinical setting to owercome or bypass MDR will also be discussed.