Aim To look for novel small-molecule inhibitors of CDK9 through structure-based virtual screening and biological activity determination.Methods Homology modeling of CDK9 was based on the 3-D structure of other cyclin-dependent kinase family members,and then virtual screening by DOCK(molecular docking)of database of small molecule was carried on.MTT method was used in inhibition of tumor cell growth in vitro,while Western blot was used for further study of molecular mechanisms.Results From the top 1000 compounds with the best DOCK energy score,27 compounds were selected for biological assay based on the diversity of chemical structure and functional group.12 of 27 selected compounds showed significantly inhibition activity on tumor cell proliferation,and only one compound in 12 with half-maximum inhibition concentration(IC50)values less than 20 ?mol?L-1 named C-21 was selected for further molecular mechanism study.The western blotting data showed C-21 compound could effectively inhibit CDK9 from phosphorylating large subunit C-terminal of RNA polymerase Ⅱ in a dose-dependent manner.Conclusions Through homology modeling,virtual screening by computer,determination of biological activity and experimental studies of molecular mechanism,a new promising lead compound targeted for CDK9 was found and confirmed.

BACKGROUND:Poultry mesenchymal stem cels are a particular subset of pluripotent adult stem cels derived from the mesoderm, which have great application prospects because of their strong proliferation and multi-directional differentiation potential. OBJECTIVE:To review the source, separation, purification, culture and differentiation of poultry mesenchymal stem cels, and to provide the theoretical foundation and experimental basis for the further research and application of poultry mesenchymal stem cels. METHODS:PubMed and CNKI databases were searched by the first author using key words of “mesenchymal stem cels, poultry, chicken, isolation, culture, differentiation” in English and in Chinese, respectively, to retrieve relevant articles published from 1990 to 2014. Literatures addressing induced poultry mesenchymal stem cels were included, and 42 articles were chosen for further analysis eventualy. RESULTS AND CONCLUSION: Poultry mesenchymal stem cels have great application prospects in the aspects of establishingin vitro model of poultry cels, studying poultry disease pathogenesis, animal nutrition and meat quality control. Its origin source is wide and easy to obtain. Isolation, purification, culture and biological characteristics of mesenchymal stem cels from different tissues are different. But, the study on poultry mesenchymal stem cels is stil in the exploration process, and there are many technical problems to be solved.

Objective To assess the relationship between the recurrence of esophageal varices fol?lowing endoscopic esophageal varix ligation (EVL) and esophageal collateral veins(ECV)under endoscopic ultrasound ( EUS) , and analyze the predictive value of EUS for recurrence of esophageal varices. Methods Sixty patients with cirrhotic portal hypertension combined with esophageal varices underwent EVL for eradica?tion of varices. Endoscopy and EUS were performed before ligation to detect and describe the type of esopha?geal varices, and grade, location, and the number of ECV. Over a 12?month period, variceal recurrence was examined. The statistical analyses were performed to assess the relationship between esophageal varices fol?lowing EVL and ECV. Results Of the 60 patients, 29 ( 48?3%) had variceal recurrence within 12 months after EVL. Univariate logistic regression analysis showed that severe peri?ECV ( OR=22?67;95%CI:4?37? 117?47, P<0?001) ,severe para?ECV( OR=16?31;95%CI:0?84?108?14, P=0?018) , multiple peri?ECV ( OR=22?67;95%CI:4?37?117?47, P<0?001) , and the presence of perforating veins ( OR=6?67,95%CI:1?46?30?43,P=0?014) were significantly related to the variceal recurrence after EVL. Multivariate logis?tic regression model showed that severe peri?ECV ( OR=24?39;95%CI:2?34?253?78,P=0?008) and mul?tiple peri?ECV (OR=24?39;95%CI: 2?34?253?78,P=0?008) severe para?ECV(OR=19?42; 95%CI:4?84?148?54,P=0?012) remained independent prognostic factors for variceal recurrence. The sensitivity and specificity of multivariate logistic regression model in predicting variceal recurrence were 89?2% and 90?5%, respectively (prognostic value AUC=0?946).The sensitivity and specificity were 86?4% and 87?7% in pre?dicting variceal recurrence( prognostic value AUC=0?871) . Conclusion Recurrence rate of esophageal var?ices after EVL is high. EUS can clearly depict ECV. Severe peri?ECV and multiple peri?ECV are significant and independent prognostic factors associated with variceal recurrence risk. EUS before EVL will help predict variceal recurrence after EVL.

Objective To assess the clinical value of endoscopic ultrasonography ( EUS ) for predicting esophageal varices ( EV ) progression in patients with hepatitis B virus ( HBV )-related hepatocirrhosis. Methods A retrospective cohort study was performed on 299 HBV-related hepatocirrhosis patients with light EV in Tianjin Second People′s Hospital admitted from September 2014 to September 2015. The diameter and number of peri-esophageal collateral veins ( ECV ) and para-ECV were measured and described by EUS. The first EUS examination time was the starting point, and the follow-up of 24 months or EV progression was the end. Risk factors of EV progression were evaluated by multivariate Cox regression model, and the predictive value of EUS for EV progression was analyzed by receiver operating characteristic ( ROC) curve. Results The cumulative incidence of EV progression was 2. 3％ ( 7/299 ) , 14. 8％( 44/297) , 33. 7％ ( 96/285) and 40. 0％ ( 120/273) at 6 months, 12 months, 18 months and 24 months of follow-up, respectively. The results of multivariate Cox regression analysis showed that the diameter of peri-ECV ( P=0. 0112, HR=1. 3232, 95％CI: 1. 0656-1. 6429 ) , the number of peri-ECV ( P=0. 0001, HR=1. 3666, 95％CI:1. 1634-1. 6052) and para-ECV diameter ( P=0. 0002, HR=1. 3641, 95％CI:1. 1558-1. 6100) were risk factors for EV progression. The use of nucleoside analogues treating HBV (P=0. 0020, HR=0. 4969, 95％CI: 0. 3186-0. 7751) and non-selective β-blockers descending portal venous pressure ( P=0. 0765, HR=0. 5732, 95％CI:0. 3097-1. 0611) were the protective factors for EV progression. The results of ROC curve analysis showed that the diameter of peri-ECV[ P<0. 001, area under the curve (AUC)= 0. 850, 95％CI: 0. 804-0. 895], the number of peri-ECV (P<0. 001, AUC=0. 831, 95％CI: 0. 784-0. 878), the diameter of para-ECV (P<0. 001, AUC=0. 924, 95％CI: 0. 895-0. 954) , and the number of para-ECV ( P<0. 001, AUC=0. 761, 95％CI: 0. 704-0. 817 ) had higher predictive value for EV progression;and the optimum cut-off values of each index were 1. 85 mm, 3. 5, 3. 35 mm, and 4. 5, respectively. The accuracies of prediction for EV progression were 76. 60％, 75. 19％, 84. 48％ and 70. 29％, respectively. Conclusion EUS can be used to predict EV progression in HBV-related hepatocirrhosis patients. Peri-ECV diameter>1. 85 mm, number>3. 5, and para-ECV diameter>3. 35 mm, number>4. 5 suggest a high risk of EV progression. For patients with HBV-related hepatocirrhosis complicated with mild EV, nucleoside analogues to anti-HBV and non-selective β-blockers to reduce portal hypertension can prevent EV progression.

Objective To assess the predictive value of endoscopic ultrasonography(EUS)for esophageal varices(EV)bleeding by studying the relationship between esophageal collateral veins(ECV), portal vein(PV)trunk with its main branches and EV bleeding. Methods A retrospective cohort study of 114 cases of moderate and severe EV was conducted. The ECV level was determined through EUS. At the same time,diameters of PV,azygos vein(AIV)and spleen vein(SV)were measured through EUS. The predictive value of ECV level and diameters of PV, AIV, SV for EV bleeding were assessed during the 1-year follow-up, which started from the first EUS examination to EV bleeding or the end of follow-up. Results Single factor Cox regression analysis showed severe peri-ECV varices had higher risk than mild in EV bleeding(HR=4.081,95%CI:1.833-9.086,P=0.001); severe para-ECV varices had higher risk than mild in EV bleeding(HR= 4.042, 95%CI:1.814-9.005,P= 0.001). Multivariable Cox retrospective analysis showed ECV level was an effective predictor for EV bleeding, when the peri-ECV and para-ECV were severe varices, EV bleeding risk increased to 3.831 3(P=0.004 3)and 3.493 3(P=0.003 1) times compared with mild respectively. Diameters of PV,AIV and SV could predict EV bleeding(PV AUC=0.959,P<0.001;AIV AUC=0.958,P<0.001;SV AUC=0.830,P<0.001).In addition, when diameter of PV>13.65 mm(sensitivity=0.94, specificity=0.84), AIV>8.65 mm(sensitivity=0.94, specificity=0.89),SV>9.45 mm(sensitivity=0.90, specificity=0.67), EV bleeding risk increased significantly. Conclusion EUS is helpful to predict the risk of moderate and severe EV bleeding, and severe varices of ECV,PV,AIV,and SV can be used as indicators to predict risk of EV bleeding.

Objective:To compare reconstruction of acromioclavicular ligament versus internal fixation of acromioclavicular joint with clavicle hook plate in the treatment of Rockwood Ⅲ-Ⅴ acromioclavicular dislocation by reconstruction of coracoclavicular ligament with suture anchor.Methods:A retrospective analysis was conducted of the 56 patients who had been treated for Rockwood Ⅲ-Ⅴ acromioclavicular dislocation from January 2015 to June 2019 at Department of Orthopaedic Trauma, Qilu Hospital of Shandong University (Qingdao). Of them, 26 were treated by reconstruction of coracoclavicular ligament with suture anchor plus reconstruction of acromioclavicular ligament (reconstruction group) and 30 by reconstruction of coracoclavicular ligament with suture anchor plus internal fixation of acromioclavicular joint with clavicle hook plate (plate group). The 2 groups were compared in terms of operation time, intraoperative blood loss, Constant-Murley score and Subjective Shoulder Rating System (SSRS) score at the last follow-up, and complications.Results:The 2 groups were comparable because there were no significant differences between them in the baseline data before operation ( P>0.05). The reconstruction group was followed up for 6 to 15 months (average, 7.9 months) while the plate group for 7 to 18 months (average, 11.3 months). The average operation time was (79.9±12.6) min for the reconstruction group and (69.1±8.5) min for the plate group, showing a significant difference ( P<0.05). No significant difference was found between the 2 groups in the intraoperative blood loss [(68.5±19.1) mL versus (65.0±16.6) mL] ( P>0.05). The differences were statistically significant between the 2 groups in Constant-Murley score (87.9±3.4 for the reconstruction group versus 91.9±3.5 for the plate group) and in SSRS score (85.1±4.1 for the reconstruction group versus 88.6±3.0 for the plate group) ( P<0.05). All the wounds healed well in the reconstruction group except for one patient who reported numbness around the wound which disappeared spontaneously 3 months postoperation. In the plate group, incision infection occurred in 2 cases, the redness and swelling in one which responded to dressing change 3 weeks later and numbness around the incision in one which was recovered 5 months after operation. Conclusions:Both surgical procedures can achieve good to excellent clinical outcomes. Although reconstruction of both acromioclavicular and coracoclavicular ligaments takes more operation time, it may lead to better Constant-Murley and SSRS scores and fewer complications, and spare secondary operation.

Objective: To study clinical characteristics and treatment after colonscopic perforation, and to determine risk factors for postoperative complications. Methods: Cases diagnosed as colonoscopic perforation within 7 days after colonoscopy in Peking Union Medical College Hospital between January 2010 and January 2017 were reviewed. Data regarding demography (age, sex), clinical information (comorbidities, medication history of glucocorticoid, length of hospital stay), colonoscopy (whether endoscopic therapy or anesthesia was performed, intestinal cleanliness), perforation (region, diagnosing time) and operation (laparotomy or laparoscopic operation, procedure, post-operational complications) were collected. Single factor analysis and Spearman correlation analysis were employed to determine the risk factors of postoperative complications. Results: A total of 14 colonoscopic perforation cases were identified and included in this study, and the overall perforation rate was 0.03%. Most perforations occurred in rectum (2 cases) and sigmoid colon (8 cases). Twelve perforation patients received operational treatment, of who 6 developed postoperative complications, including 3 cases of incision infection, 2 cases of peritoneal infection, 1 case of catheter-related infection and 1 case of pulmonary embolism. Spearman correlation analysis showed that preoperative medication of glucocorticoid and non-rectosigmoid perforation were positively related to postoperative complications (both correlation coefficients were 0.707, P=0.01), while perforation diagnosed immediately and satisfying intestinal cleanliness were negatively related to it (both correlation coefficients were -0.667, P<0.05). Conclusion Perforations are rare but severe complications of colonoscopy, and surgical interventions are necessary in most cases. Postoperative complications were significantly related to perforation sites, preoperative medication of glucocorticoid, perforation diagnosis time and intestinal cleanliness.

Objective:To investigate the clinical and genetic characteristics of cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) with replication factor C subunit 1 (RFC1) gene mutation to improve the understanding of this disease.Methods:A case of CANVAS diagnosed in the Peking University Third Hospital in January 2021 was reported. Detailed genetic analyses of ataxia were performed with DNA extracted from the peripheral blood of the patient. Studies including pathogenic variants of RFC1 gene causing CANVAS were reviewed and the clinical and genetic characteristics of the disease were summarized.Results:The patient was a 51-year-old female with the prominent manifestation of progressive walking instability. And the clinical data met the diagnostic criteria of CANVAS. The genetic tests excluded other hereditary ataxia mutations and identified the biallelic expansion of the pathogenic variant structure (AAGGG)exp repeat amplification in RFC1 gene. A total of 14 studies on CANVAS with RFC1 gene mutation were reviewed. The overall mutation rate of RFC1 gene in CANVAS was 68%-100%, and it varied in sporadic and familial CANVAS. And the mutation had ethnic differences.Conclusions:Among adult patients with late-onset ataxia, the combination of brain magnetic resonance imaging, electrophysiology tests and vestibular function examination is beneficial to the identification of CANVAS. And the genetic test of RFC1 gene has significant value in the diagnosis of this disease. This patient with CANVAS expands the disease spectrum of ataxia in China, and confirms that RFC1 gene mutation is of great significance in the screening of ataxia disorders in the Chinese population.

Objective To investigate the effects from head angle and locking times of locking screws on mechanical properties of the screw-plate system, so as to provide a theoretical basis for doctors to select appropriate locking screws and master the locking times in clinical surgical procedure. Methods Locking screws with different head angles were selected to match with locking compression plates in the case of different locking times, and cantilever bending method was used to compare the differences of mechanical properties in each group. Results There were significant differences in failure load and bending stiffness between locking compression plate and locking screw with different head angles (P<0-05). The mechanical properties of the screw-plate system with the best locking degree were optimum. There was no significant difference between 3 time-locking and 1 time-locking (P>0-05). The failure modes of locking screw with different head angles and different locking times were different, and the failure mode of locking screw had a positive correlation with its head angle and locking times. Conclusions The differences in mechanical properties between locking screw with different head angles and locking compression plate cannot be neglected. It is suggested that doctors should choose locking screw and locking compression plate with the best locking degree in clinical procedure, and choose the right torque wrench to lock in multiple times if necessary, thus to prevent screw loosening from affecting recovery of the patients.

We constructed and expressed an anti-CD3/anti-Pgp (P-glycoprotein) diabody previously. However, the two chains of diabody are associated non-covalently, resulting in being capable of dissociating. The aim of this study is to enhance the stability of the diabody. We introduced cysteine residues into the CD3 or Pgp V-domain to covalently lock the two chains together. The disulphide crosslinked diabody were expressed by Escherichia coli (E. coli) 16C9 and purified by a cation exchange column and an anti-Etag affinity chromatography. The purified proteins were verified through SDS-PAGE. Flow cytometry (FCM) was used to analyse the binding properties, competitive binding capacity and stability in vitro. The dsPpg-diabody failed to form disulphide bond properly. The designed disulphide bridge between the different chains of dsCD3-diabody was formed correctly. FCM demonstrated the dsCD3-diabody has specific antigen binding activity, the same binding activity and competitive binding activity as its parent diabody. The dsCD3-diabody retained the full activity even after 72 h incubation at 37 degrees C in human serum, in contrast, the parent diabody began to lose activity after only 1 h and lose all its activity 24 hours later. The induced disulphide bond in the CD3 V-domain effectively enhanced the stability of anti-CD3/anti-Pgp diabody. The method of stabilizing a diabody by introducing a disulphide bond into is practical.
ATP Binding Cassette Transporter, Sub-Family B ; immunology ; Antibodies, Bispecific ; biosynthesis ; chemistry ; genetics ; immunology ; Binding, Competitive ; CD3 Complex ; immunology ; Cell Line ; Disulfides ; chemistry ; Drug Stability ; Escherichia coli ; genetics ; metabolism ; Humans