Piper nigrum L. is an evergreen climbing vine, which belongs to the genus Piperia in the Piperaceae family. Piper nigrum L., which known as the “king of spices”, is used as both food and medicine. The main active substances in Piper nigrum L. are alkaloids mainly composed of amides, and essential oil, as well as phenolic compounds. In this paper, the chemical compositions, especially amide alkaloids, and their biological activities of Piper nigrum L. were summarized. These studies showed that Piper nigrum L., as a medicinal and food plant, had a wide range of biological activities and was deserved further research and in-depth utilization.

Glutathione peroxidase （GSH-Px） is a key selenoenzyme that protects the body from oxidative damage. A series of small molecular organic selenium compounds have been designed and synthesized as functional mimics of GPx, among which isoselenazolones are the most widely studied. Taking ebselen as a representative, the catalytic mechanism of isoselenazolones in mimicing GSH-Px activity in vivo, the therapeutic effects of isoselenazolones in stroke, sensorineurium deafness and tinnitus, treatmentresistant depression （TRD） and coronavirus disease 2019 （COVID-19）, and research on their chemical synthesis methods were summarized and discussed in this paper.

Aldehyde dehydrogenase 2 (ALDH2) is one of important factors against from the damage under oxidative stress in human body. A high proportion of East Asians carry ALDH2 inactive mutation gene. There are many diseases closely related to ALDH2, such as cardiovascular diseases, neurodegenerative diseases and liver diseases. Recent studies also have found that ALDH2 is associated with ferroptosis. Therefore, ALDH2 has becoming a potential target for the treatment of the above related diseases. Several types of small molecule activators with potential value of clinical application have been reported. The research progress on the structure and function of ALDH2 , the relationship with human diseases and its activators were summarized in this paper.

Over the years of exploration and development, the surgical techniques and prognosis of liver transplantation in China have been significantly improved, resulting in a notable decrease in the prevalence of postoperative complications. However, ischemic-type biliary lesion remain a non-negligible issue. The Third Affiliated Hospital of Sun Yat-sen University formulated and published the "Expert Consensus on the Diagnosis and Treatment of Ischemic-Type Biliary Lesions after Liver Transplantation in Mainland China" in 2015, which has now been updated into a guideline based on current conditions and literature reports. This guideline elaborates in detail on the definition, incidence, pathogenesis, diagnosis, prevention of high-risk factors, and treatment of ischemic-type biliary lesion, aiming to provide standardized and normative guidance for the diagnosis and treatment of ischemic-type biliary lesion after liver transplantation, thereby reducing the rate of re-transplantation and fatality, and to improve the overall quality of life of liver transplant recipients.

Objective To explore the preventive effect of percutaneous endoscopic gastrostomy (PEG) on aspiration pneumonia in patients with dysphagia.Methods The clinical data of 43 patients undertaking PEG was retrospectively collected and the incidence of aspiration pneumonia,microbiological examination of sputum and antibiotics use before and after PEG in all the patients were compared.Results After PEG,the incidence of aspiration pneumonia decreased significantly from 90.7％ to 53.5％ according to clinical diagnosis,from 70.4％ to 18.5％ according to the chest imaging.The use of β-lactamase inhibitor compound decreased significantly,but the detection rate of pseudomonas aeruginosa increased significantly compared with that before PEG.Conclusion PEG can decrease the incidence of aspiration and antibiotics use,and may increase the chances of pseudomonas aeruginosa colonization in the lower respiratory tract.

Objective: To analyze the distribution and the molecular biological characteristics of variant subtypes (H5, H7 and H9) of avian influenza virus (AIV) in the live poultry related external environment of Quanzhou form 2014 to 2017, and provide regional references for the prevention, control and early-warning of human infections. Methods: Samples from monitoring sites of live poultry were collected in Quanzhou from 2014 to 2017. Influenza A and variant subtypes of AIV (H5, H7 and H9) were detected by real time RT-PCR, and the detection results were further analyzed statistically. Furthermore, the HA and NA genes of four representative H7N9 strains were sequenced, and the results were further analyzed with DNAstar and MEGA7.0. Results: Among the samples from external environment, the positive rate of nucleic acid of influenza A was 29.04% (377/1 289), of which the positive rates of H5, H7 and H9 subtypes were 3.80%, 13.34% and 12.02%, respectively. The positive rate of H7N9 was higher than those of the other subtypes in all monitored years, of which the highest rate was found in 2017 (21.88%). As to the different types of samples, chopping board possessed the highest positive rate of influenza A (65.4%), followed by waste water (59.3%) and drinking water for the poultry (29.6%). Among the different monitoring sites, the positive rate of poultry farm is 6.94%, far lower than that in the open air (61.7%) and the live poultry trading market (52.8%). Sequencing of the HA and NA genes of four strains of H7N9 showed that the strains from external environment and the strains from H7N9 patients belonged to Pearl River Delta and Yangtze River Delta lineage, respectively. The cleavage sites of HA proteins of these four strains were all PKGR/G without highly pathogenic mutation. Meanwhile, they were low pathogenic H7N9 without oseltamivir resistant mutation (R292 K in NA), while they all possessed the E627 K mutation in the PB2 genes associated with virulence. Conclusions H7N9 AIV existed in the live poultry related external environment of Quanzhou, especially the farmers’ and the live poultry trading market, so that more persistent surveillance could be needed in the future.

ObjectiveTo explore the influence of portal vein thrombosis (PVT) on the clinical efifcacy of endoscopic esophageal variceal ligation (EVL) in cirrhotic patients with esophagogastric variceal hemorrhage (EVH).MethodsClinical data of 314 cirrhotic patients with EVH who underwent endoscopic EVL and were followed up for more than 6 months in the Third Afifliated Hospital of Sun Yat-sen University between January 2005 and December 2014 were retrospectively analyzed. The informed consents of all patients were obtained and the local ethical committee approval was received. The patients were divided into the PVT group and the control group according to whether they had PVT during treatment. Among the 72 patients in the PVT group, 61 were males and 11 were females with the mean age of (50±11) years old.Among the 242 patients in the control group, 206 were males and 36 were females with the mean age of (47±11) years old. The clinical efifcacy of two groups was compared, and the correlation between PVT and the elimination rate of esophageal varices (EV) as well as the recurrent bleeding rate of EV was analyzed. The number of EVL treatment period in two groups was compared usingt test and the rate was compared using Chi-square test. Univariate logistic regression analysis was conducted for the correlation between PVT and the elimination rate, recurrent bleeding rate of EV.ResultsThirty-six patients in the PVT group and 115 patients in the control group developed acute EVH. After EVL, the emergency hemostatic rate of both groups was 100%. The elimination rate of EV in the PVT group was 76%(55/72), signiifcantly lower than 90%(218/242) in the control group (χ2=9.166,P<0.05). The number of EVL treatment period in the PVT group was 3.4±1.6, significantly more than 2.8±1.1 in the control group (t=3.065,P<0.05). The recurrent bleeding rate of EV in the PVT group was 36%(26/72), signiifcantly higher than 21%(51/242) in the control group (χ2=6.779,P<0.05). PVT was a risk factor for both the elimination rate of EV (OR=0.356, 95%CI: 0.179-0.709,P<0.05) and the recurrent bleeding rate of EV (OR=2.383, 95%CI: 1.354-4.196,P<0.05). ConclusionPVT is a risk factor for both the elimination rate of EV and the recurrent bleeding rate of EV in cirrhotic patients with EVH treated by endoscopic EVL.

ObjectiveTo investigate the application value of endoscopic retrograde cholangiopancreatography (ERCP) in biliary stricture following liver transplantation (LT).MethodsClinical data of 47 patients with biliary stricture following LT treated with ERCP in the Third Affiliated Hospital of Sun Yat-sen University between January 2008 and January 2014 were retrospectively studied. The informed consents of all patients were obtained and the local ethical committee approval had been received. Among the 47 patients, 41 were males and 6 were females with the age ranging from 24 to 62 years old and the median of 51 years old. Anastomotic stricture was observed in 31 cases and non-anastomotic stricture in 16 cases. ERCP was performed on patients to localize biliary stricture and then papillotomy was performed under the support of guide wire. The stricture was dilated progressively by dilating catheter or columnar balloon through the guide wire. Endoscopic nasobiliary drainage or plastic stent placement was chosen according to the ERCP results. The evaluation of curative effect was graded by cure, improvement, inefifcacy and restenosis.ResultsAll the 47 patients underwent ERCP successfully with totally 112 times. Nasobiliary drainage was performed 79 person-times, stent placement 33 person-times. Among the 31 patients with anastomtic stricture, 28 were cured and 3 were improved. Among the 16 patients with non-anastomtic stricture, 5 were cured, 3 were improved, and 8 were ineffective. The total cured rate of all the patients was 70% (33/47) and the effective rate was 83% (39/47). The incidence of complications was 9% (4/47), including 2 cases of mild pancreatitis, 1 case of hyperamylasemia and 1 case of biliary tract infection.ConclusionERCP is safe, effective and integrated in diagnosis and treatment for biliary stricture following LT, which is the ifrst choice for non-surgery treatment.

ObjectiveTo investigate the changes and role of β-arrestin 1 in the course of non-alcoholic fatty liver disease (NAFLD) progressing to hepatocellular carcinoma (HCC). MethodsEighty healthy male C57BL/6 mice were randomized into the vegetarian diet group and the high fat diet group according to the random number table with 40 mice in each group. Mice in the vegetarian diet group were fed with vegetarian diet (13% calories in fat) and mice in the high fat diet group were fed with high fat diet (58% calories in fat). Eight mice in each group were decapitated at the end of 9 and 24 weeks. The rest mice in each group were decapitated at the end of 48 weeks. The incidence of HCC of two groups was observed. The expression of proteinβ-arrestin 1 in the liver tissues of mice was detected by Western blot and the mRNA level was examined using TaqMan real time fluorescence quantitative RT-PCR. The incidence of HCC in two groups was compared using Fisher's exact test, and the protein β-arrestin 1 expression and mRNA level of two groups were compared usingt test. Spearman correlation analysis was used to evaluate the relationship between protein β-arrestin 1 expression, mRNA level and the feeding duration of high fat diet in high fat diet group.ResultsThe incidence of HCC in the high fat diet group was 18% (4/22), which was significantly higher than 0 (0/23) in the vegetarian diet group (P=0.034). The expression level of protein β-arrestin 1 in liver tissues of mice in the high fat diet group was 2.4±0.5 in the 9th week, which was significantly higher than 1.5±0.4 in the vegetarian diet group (t=2.779,P<0.05). The β-arrestin 1 mRNA level in liver tissues of mice in the high fat diet group in the 9th, 24th and 48th week were 4.1±0.8, 7.8±2.1 and 12.5±1.2 respectively, which were all significantly higher than 2.6±0.7, 3.6±0.6 and 6.9±1.2 in the vegetarian diet group (t=4.029, 5.522, 9.487;P<0.05) . The protein β-arrestin 1 and mRNA level in HCC tissues of mice in the high fat diet group in the 48th week were 4.6±0.5 and 22.0±3.2, which were signiifcantly higher than 1.6±0.4 and 12.5±1.2 in liver tissues at the same period (t=9.600, 7.837;P<0.05). The protein β-arrestin 1 and mRNA level in high fat diet group were positively correlated with the duration of high fat diet (r=0.949, 0.922;P<0.05). Conclusions It is likely to develop NALFD for the mice fed with high fat diet, and the incidence of HCC is signiifcantly increased. β-arrestin 1 may play a role of accelerating the course of NAFLD progressing to HCC.

Objective To investigate the perioperative management of endoscopic retrograde cholangiopancreatography (ERCP) in the treatment of biliary complications following liver transplantation (LT). Methods A total of 102 patients with biliary complications following LT undergoing ERCP in Digestive Endoscopy Center, the Third Afifliated Hospital of Sun Yat-sen University from December 2008 to December 2012 were included in this prospective study. There were 90 males and 12 females with the age ranging from 23 to 65 years old and a median of 56 years old. The informed consents of all patients were obtained and the ethical committee approval was received. Positive preoperative preparations were given to the patients:personalized psychological counseling, strict disinfection of surgical instruments, application of preoperative drugs, et al. The operators and nursing staff cooperated closely during the operation. Symptomatic treatments such as fasting, transfusion, anti-infection, antacids, somatostatin were given to the patients after operation. The nasobiliary ducts were properly ifxed and the conditions were closely observed. Health guidance was given to the patients after hospital discharge. Results In 102 patients, 94 patients were treated by ERCP successfully with the success rate of 92.2% (94/102). The curative rate was 77%(72/94), the improvement rate was 20%(19/94) and the total effective rate was 97%(91/94). Postoperative complications were observed in 15 cases including hyperamylasemia (n=8), mild pancreatitis (n=4), bleeding of the papillary muscles incision (n=3), and all were cured by conservative treatments. Conclusions Positive preoperative psychological counseling, close collaboration of medical staff during the operation, close observation on the postoperative complications and health guidance after hospital discharge are important factors for the success of ERCP in treating biliary complications following LT.