To construct a recombinant expression system for a single-domain antibody targeting the urease of Helicobacter pylori(Hp),this study employed several strategies.First,using artificial intelligence(AI)auxiliary tools such as Pymol,I-TASSER,and ClussPro2,the molecular interactions between different antibodies and Hp urease subunit B(UreB)were analyzed.The fully humanized single-domain antibody UreBAb was identified as the primary research target.Next,the UreBAb gene sequence was optimized based on Escherichia coli codon preferences,and was inserted into expression vectors such as pET28a and pE-SUMO.The resulting recombinant expression strains were obtained by transforming Escherichia coli Rosetta(DE3).Recombinant antibody proteins were prepared through IPTG induction,and its activity was detected using extracted Hp urease as the antigen.SDS-PAGE analysis confirmed the correct expression of both UreBAb and SUMO-UreBAb,with protein yields of 0.34 mg/mL and 0.41 mg/mL,respectively.Unidirectional immunodiffusion experiments further confirmed that both recombinant antibodies exhibited strong affinity for Hp UreB antigen,with inhibition rates of 51.27%and 74.07%,respectively.Additionally,leveraging artificial intelligence tools such as AlphaFold2,cluspro2,mCSM-AB,OSPREY,and FoldX,the study evaluated and analyzed key binding sites and mutational strategies affecting the stability of the antigen-antibody complex.Subsequently,nine UreBAb evolution mutants were constructed,and their binding activities with the antigen were enhanced.Among these,the I107W mutant showed the most significant improvement,achieving a 24.95%increase compared to the wild-type UreBAb.This research lays a solid foundation for the development of fully humanized single-domain antibodies against Hp.

Objective To explore the effect of glioma stem cells with high expression of protein tyrosin phosphatase receptor type Z1 (PTPRZ1 )on the phenotypic polarization and phagocytosis of tumor-associated macrophages and its regulatory mechanism.Methods GSCs and non-stem tumor cells (NSTCs) were screened out from human glioblastoma (GBM) specimens using flow cytometry,and the PTPRZ1 expression in paired GSCs and NSTCs were detected.Human peripheral blood mononuclear cells (PBMC)-derived CD14+monocytes were exposed to the conditioned medium from glioma cells or recombinant chemokine C-C motif ligand 20 (CCL20)for TAM polarization.Stable PTPRZ1 knockout GSCs (PTPRZ1-KO GSCs) were constructed using CRISPR/Cas9. TAM phagocytosis to GSCs,NSTCs,PTPRZ1-Control GSCs (PTPRZ1-Ctrl GSCs)and PTPRZ1-KO GSCs and the expression of immunosuppressive phenotype (M2) polarization marker CD163 were examined using flow cytometry.Differentially expressed genes (DEGs ) between paired GSCs and NSTCs were determined using a bulk RNA-sequencing dataset (GSE54791 )from Gene Expression Omnibus (GEO).A gene set informing worse outcome of patients with GBM was generated using The Cancer Genome Atlas (TCGA)-GBM cohort.By intersecting the aforementioned gene set with the gene set that encodes for human membrance proteins,the PTPRZ1 gene is obtained.Gene set enrichment analysis (GSEA)was used for pathway enrichment analysis to compare the differentially regulated pathways between GBMs with high or low PTPRZ1 expression.Bulk RNA sequencing,qRT-PCR and Western blotting were used to identify the DEGs between PTPRZ1-KO GSCs and PTPRZ1-Ctrl GSCs.Results GSCs were more capable of escaping from TAM phagocytosis than NSTCs (P<0.05 )and had specifically up-regulated PTPRZ1 expression.PTPRZ1-KO significantly suppressed GSCs escaping from TAM phagocytosis (P<0.01 ). GBMs with high PTPRZ1 expression showed significant inhibition of pathways mediating phagocytosis (P<0.05).The expression of CCL20 as a M2 TAM polarization chemokine was significantly down-regulated in PTPRZ1-KO GSCs (P<0.05 ).Treatment with recombinant CCL20 up-regulated the expression of CD163 as a M2 TAM marker in TAM.Conclusion PTPRZ1+GSCs mediate M2 TAM polarization and inhibit TAM phagocytosis,which may be related to the up-regulation of CCL20 in PTPRZ1+GSCs.

A 3-year-old male patient was diagnosed with neurofibromatosis type 1(NF1) for two years. The patient has multiple neurofibromas in retroperitoneum, lumbococcygeal paravertebral, lumbosacral spinal canal, and foramina. Due to retroperitoneal mass compression, the child suffered from urological complications such as hydronephrosis, ureterdilation, neurogenic bladder, etc., which seriously affected the urination function and resulted in multiple surgical treatments. Currently, the patient has been treated with mitogen activates extracelluar signal-regulated kinases(MEK) inhibitor selumetinib targeted therapy, and has voluntarily urinated, and his general state is better than before medication. The diagnosis and treatment of this case reflects the importance of multidisciplinary collaboration in the diagnosis and treatment of rare diseases.

Objective:To evaluate the efficacy and safety of endoscopic retrograde cholangiopancreatography (ERCP) after pancreaticoduodenectomy and endoscopic selection strategies.Methods:Clinical data of 34 patients treated with ERCP after pancreaticoduodenectomy at the Endoscopic Center of the First Affiliated Hospital of Air Force Medical University from January 2013 to December 2021 were retrospectively analyzed. The success rates of endoscopic insertion, diagnosis, treatment and ERCP, and the incidence of adverse events were analyzed.Results:Fifty ERCP treatments were performed in 34 patients. The success rates of endoscopic insertion, diagnosis, treatment, and ERCP after pancreaticoduodenectomy were 92.0% (46/50), 93.5% (43/46), 88.4% (38/43) and 76.0% (38/50), respectively. The success rates of ERCP assisted with colonoscope and balloon-assisted enterosocpe were 76.0% (19/25) and 75.0% (18/24), respectively. There were 3 adverse events, including 1 case of anastomotic mucosa tear during surgery, 1 case of cardiopulmonary arrest and 1 case of postoperative cholangitis.Conclusion:ERCP is effective and safe after pancreaticoduodenectomy in general. ERCP assisted with colonoscope and balloon-assisted colonoscope shows similar success rate after pancreaticoduodenectomy.

To investigate the effects of the S-curve leakage testing method on the detection of flexible endoscope and occurrence of medium to high-level faults of flexible endoscope. A convenience sampling method was used to study the information of endoscopic leak detection at the digestive endoscopic centre of the First Affiliated Hospital of Air Force Medical University. From July 2016 to December 2017, 58 endoscopes which received conventional leakage testing were set as the control group (29 116 tests). From January 2018 to June 2019, 56 endoscopes which received S-curve leakage testing were set as the observation group (28 112 tests). The results showed that the detection proportion of angular abnormalities in the observation group was higher than that in the control group [65.6% (59/90) VS 40.4% (36/89), χ2=11.330, P<0.001]. However, the detection proportion of medium to high-grade faults such as damaged charge coupled device (CCD) components and broken insertion section in the observation group was lower than that in the control group [0.04% (10/28 112) VS 0.08% (23/29 116), χ2=4.680, P=0.030]. Moreover, the overall maintenance cost was lower in the observation group than that in the control group (313.7 thousand yuan VS 942.6 thousand yuan). It is indicated that the S-curve leakage testing method can detect low-level endoscopic faults early such as angular abnormalities, and reduce the occurrence of medium to high-level endoscopic faults, which contributes to cost reduction and efficiency increase.

Objective:To explore the efficacy of endoscopic retrograde cholangiopancreatography (ERCP) biliary stent implantation in patients with unresectable malignant biliary stricture (MBS) and the influencing factors of overall survival.Methods:The clinical data of 346 patients who underwent ERCP biliary stent implantation due to MBS from May 2013 to October 2016 in Xijing Digestive Disease Hospital of Air Force Military Medical University, Shanxi Bethune Hospital and Mengchao Hepatobiliary Hospital of Fujian Medical University were retrospectively analyzed, and the efficacy, complications and risk factors affecting overall survival were also analyzed.Results:After ERCP biliary stent implantation, the levels of total bilirubin, γ-glutamyl transpeptidase, alkaline phosphatase and alanine aminotransferase were lower than those before surgery (all P < 0.01). The incidence of infection after operation was 14.7% (51/346), and the incidence of biliary infection was 13.0% (45/346). The incidence of post-ERCP pancreatitis (PEP) was 4.6% (16/346). The median survival time after ERCP was 131.0 d (70.3 d, 246.5 d). Multivariate Cox regression analysis showed that the independent risk factors affecting the overall survival patients included the hilar bile duct stenosis ( HR = 1.85, 95% CI 1.44-2.38, P < 0.01), preoperative bilirubin level exceeding the upper limit of normal level by 5 times ( HR = 1.75, 95% CI 1.30-2.36, P < 0.01), carbohydrate antigen 199 level exceeding the upper limit of normal level by 10 times ( HR = 1.27, 95% CI 1.00-1.61, P = 0.050), vascular and organ metastasis ( HR = 1.32, 95% CI 1.04-1.69, P = 0.023), and the poor jaundice decreasing level ( HR = 1.37, 95% CI 1.02-1.85, P = 0.037) . Conclusions:The ERCP biliary stent implantation is a safe and effective therapy for MBS. ERCP biliary stent implantation MBS patients with hilar bile duct stenosis, preoperative bilirubin levels more than 5 times of the upper limit of normal level, carbohydrate antigen 199 levels more than 10 times of the upper limit of normal level, vascular and organ metastasis, and poor jaundice decreasing level may have poor overall survival.

Objective:To evaluate the efficacy and safety of endoscopic retrograde cholangiopancreatography (ERCP) for patients with liver cirrhosis combined with biliopancreatic diseases.Methods:Data of 99 patients with liver cirrhosis combined with biliopancreatic diseases who received ERCP at Xijing Digestive Hospital from November 2008 to December 2017 for the first time were retrospectively studied. Success rate of ERCP and incidence of complications were analyzed.Results:The 99 cases of liver cirrhosis were mainly caused by hepatitis B virus infection (40.4%, 40/99) and unknown reasons (30.3%, 30/99), and the mean model for end-stage liver disease score was 15.4±5.3. The common bile duct stones and bile duct stricture were the most common biliopancreatic diseases, accounting for 49.5% (49/99) and 33.3% (33/99), respectively. The success rate of ERCP was 100.0%(99/99). The total postoperative complication incidence was 14.1% (14/99), among which liver cirrhosis-related complications was 3.0% (3/99); ERCP-related complications was 11.1% (11/99), including 9.1% (9/99) biliary tract infection, and 2.0% (2/99) delayed bleeding. No post-ERCP pancreatitis, perforation or death occurred.Conclusion:ERCP is safe and effective for liver cirrhosis combined with biliopancreatic diseases.

Objective: To investigate the effect of simple artifacts on the calculation of radiation dose in actual clinical operations by the aid of artificially caused CT artifacts. Methods: The phantom was scanned using CT before and after replacing the titanium alloy component. Then, the CT values were measured at different distances before and after replacement. After correcting the CT value of the titanium alloy region to the CT value of the water phantom, the doses to the phantom were calculated by using Varian′s AAA algorithm, AXB algorithm and Pinnacle system′s CCC algorithm. The absolute dose values at different distances were furtherly analyzed. Results: Varian system was consistent with Pinnacle system in evaluating the CT values. When the CT value deviated by less than 30 HU for a uniform phantom, the dose deviations of the three different algorithms were within 6.0 %-12.0 % at a distance of 0.5 cm from the body surface, and less than 1.0% at a distance of more than 1.5 cm from the body surface. When the CT value deviated by 15 HU for the lung phantom, both Varian′s AAA algorithm and Varian′s AXB algorithm showed about 1.0% dose deviation. However, the CCC algorithm of the Pinnacle system had a significant difference (5.0%) in dose values under the same conditions. Conclusions CT artifacts have noticeable effects on the calculation of radiation dose and change tissue dose distribution which may result in insufficient or excessive exposure doses.

Endoscopic retrograde cholangiopancreatography(ERCP)is a well-established advanced endoscopic technique for the diagnosis and treatment of pancreatobiliary diseases. New advances have been made in the treatment concept and techniques of ERCP in recent years. This article elaborates on the recent advances in ERCP,including the application of pancreatic duct stent,non-steroidal anti-inflammatory drugs,and aggressive hydration to prevent postoperative pancreatitis,covered metal stent for the treatment of benign bile duct stenosis,in-traluminal radiofrequency ablation for malignant bile duct stenosis,extracorporeal shockwave lithotripsy and covered metal stent for the treat-ment of chronic pancreatitis,peroral choledochoscopy for qualitative diagnosis of bile duct stenosis and huge refractory stones,definition of difficult intubation,timing of pre-cut technique,and ERCP after gastrointestinal reconstruction.

Objective To estimate the diagnostic value of cytology, DNA-ICM(DNA-image cytometry),cytology combined with DNA-ICM for pancreatic malignancy,and to explore the cut-off value for DNA-ICM. Methods Patients with suspicious pancreatic malignancy were retrospectively identified. In total,145 EUS-FNA specimens acquired from 140 separate patients were examined by cytology and DNA-ICM. Diagnostic values among cytology, DNA-ICM and the combination of the techniques in detecting pancreatic malignancy were compared. Results Compared with cytology, DNA-ICM had a lower sensitivity (63.0% VS 82.4%)and accuracy(69.7% VS 85.5%). After combining the techniques, the diagnostic value for pancreatic malignancy significantly improved compared with that by cytology(0.941 VS 0.912, P=0.007 0)or DNA-ICM only(0.941 VS 0.815, P<0.000 1). By using the Youden index, the cut-off value for DNA-ICM to detect pancreatic malignancy was one cell with DI(DNA index)≥2.5. Notably,with this standard, the sensitivity and accuracy of DNA-ICM significantly increased to 72.3% and 77.2%, and those of the combined techniques increased to 91.6% and 93.1%, respectively. Conclusion Automated DNA-ICM is an objective and effective method for pancreatic malignancy. Although DNA-ICM has a lower diagnostic value than that of conventional cytology, an improved value was obtained after combining the techniques.