Peptide cyclization, a pivotal approach to modifying linear precursors of proteins and pepticles, has been used to enhance their biological activities and serum stabilities. Recently, sortase A (SrtA) from Staphyloccus aureus becomes a promising new technology for efficiently incorporating site specific modifications into proteins, conjugating the cell surface and cyclizing the linear peptides. In this study, we constructed two recombinant expression systems, one with chitin binding domain and the other with six-histidine tag and chitin binding domain on the N-terminal of SrtA, separately. The results of enzymatic kinetics indicate that the two recombinant tags do not impair the transpeptidase activity of SrtA compared with the standard reaction reported under the same reaction condition. The two synthesized peptides with N-ternimal three glycines and C-terminal penta-amino acid motif, LPETG, were cyclized using immobilized and recycled SrtA. The SrtA-based cyclization promises to represent a simple method for easy and efficient enzymatic synthesis of large cyclic peptides.

Millettia nitida var.hirsutissima is a Chinese herbal medicine used for the treatment of gynecological diseases.An HPLC/DAD/ESI-MSn method was established for the rapid separation and characterization of bioactive flavonoids in M.nitida var.hirsutissima.A total of 32 flavonoids were detected,of which 14 compounds were unambiguously characterized by comparing their retention time,UV,and MS spectra with those of the reference standards,and the others were tentatively identified based on their tandem mass spectrometry fragmentation data obtained in the negative ionization mode on line.Nineteen of these compounds characterized were reported from this plant for the first time.

Three cyclotides were isolated from the whole plant of Viola yedoensis in this study. The two, vary peptide E and cycloviolacin Y5, were previously reported, and a novel cycloviolacin VY1 was characterized according to the interpretation of MS/MS fragmentation of peptides which were produced from the reduced and alkylated parent peptide with the digestion of Endo Lys-C, trypsin and chymotrypsin, separately. The stability of remarkable resistance to proteolytic degradation by trypsin and chymotrypsin, and that of thermal denaturation was confirmed again. Besides, the IC50 value of cycloviolacin VYI against influenza A H1N1 virus was (2.27 +/- 0.20) microg x mL(-1). It is the first cyclotide reported with anti-influenza A H1N1 virus activity in vitro assay.

Objective:To investigate the diagnostic value of serum CircRNA_0048211 expression level in postmenopausal osteoporosis (PMOP) and its correlation with bone-specific alkaline phosphatase (BALP), osteopontin (OPN), procollagen type I N-terminal propeptide (PINP) and β-crosslaps (β-CTX). Methods:Data of postmenopausal women who underwent physical examination in our hospital from January 2019 to December 2021 were collected. All subjects were measured bone mineral density (BMD) by dual-energy X-ray absorptiometry and divided into PMOP group, decreased bone mass group and normal bone mass group according to BMD level. The serum CircRNA_0048211, BALP, OPN, PINP and β-CTX levels were compared in each group. Binary logistic regression was used to analyze the risk factors of PMOP, the receiver operating characteristic curve (ROC) was drawn to analyze the diagnostic value of CircRNA_0048211, BALP, OPN, PINP and β-CTX on PMOP. The correlation between CircRNA_0048211 expression level and BALP, OPN, PINP and β-CTX was analyzed by Pearson correlation analysis. Results:A total of 218 patients were included in this study. Age is 60.52±6.83 years (range, 47-76 years), body mass index is 24.27±2.28 kg/m 2 (range, 22.18-25.73 kg/m 2) and menopausal time is 10.16±4.25 years (range, 2.30-21.80 years). There were 40 cases in PMOP group, 97 cases in osteopenia group and 81 cases in normal bone mass group. The serum CircRNA_ 0048211, BALP, OPN, PINP and β-CTX was significantly different between PMOP group, osteopenia group and normal group ( F=21.15, P<0.001; F=12.52, P<0.001; F=17.86, P<0.001; F=14.32, P<0.001; F=15.52, P<0.001). The serum CircRNA_0048211 level in PMOP group (0.37±0.08) were significantly lower than that of osteopenia group (1.05±0.46) and normal bone mass group (1.73±0.81), the difference was statistically significant ( P<0.05). The levels of BALP (28.42±7.35 μg/L), OPN (17.28±7.30 ng/ml), PINP (58.40±14.37 ng/ml) and β-CTX (1.52±0.28 μg/L) in PMOP group were significantly higher than those in osteopenia group (22.61±5.93 μg/L, 11.95±5.64 ng/ml, 49.16±11.24 ng/ml, 0.81±0.17 μg/L) and normal bone mass group (16.30±4.18 μg/L, 7.62±3.25 ng/ml, 35.48±7.12 ng/ml, 0.37±0.10 μg/L), the difference was statistically significant ( P<0.05). Binary logistic regression analysis showed that decreased CircRNA_0048211 expression level [ OR=3.53, 95% CI (2.73, 10.32)] was a risk factor for the occurrence of PMOP ( P<0.001). ROC curve showed that CircRNA_0048211≤0.76 has a diagnostic significance on PMOP, and its combination of BALP, OPN, PINP and β-CTX has the highest AUC [0.95, 95% CI (0.89, 1.00)] in diagnosing PMOP. Correlation analysis showed that CircRNA_0048211 expression level were negatively correlated with BALP, OPN, PINP and β-CTX ( r=-0.46, P<0.001; r=-0.80, P<0.001; r=-0.81, P<0.001; r=-0.69, P<0.001). Conclusion:The CircRNA_0048211 showed low expression in PMOP, which was negatively correlated with BALP, OPN, PINP and β-CTX. The combination of these five factors has certain clinical value in the diagnosis of PMOP.

Objective:To evaluate the effect of individualized blood pressure management on postoperative delirium in elderly hypertensive patients undergoing radical resection for gastrointestinal tumor.Methods:One hundred and sixty elderly hypertensive patients of both sexes, aged 60-80 yr, with body mass index of 19-28 kg/m 2, of American Society of Anesthesiologists Physical Status classification Ⅱ or Ⅲ, scheduled for elective radical resection for gastrointestinal tumor under general anesthesia, were divided into 2 groups ( n=80 each) using a random number table method: standardized blood pressure management group (group S) and individualized blood pressure management group (group I). Combined intravenous-inhalational anesthesia was performed, and BIS values were maintained at 40-60 and heart rate at 50-100 times/min during surgery in both groups. In group S, intraoperative systolic blood pressure was maintained above 90 mmHg with a decrease of less than 30% of the baseline value, while intraoperative fluctuation of systolic blood pressure was maintained less than 10% of the baseline value in group I. The use of vasoactive agents, numerical rating scale scores within 3 days after operation, and length of hospital stay were recorded. Postoperative delirium was evaluated by Confusion Assessment Method within 5 days after surgery. Results:Compared with group S, the intraoperative usage rate of norepinephrine was significantly increased, the incidence of postoperative delirium was reduced( P<0.05), and no significant change was found in the numerical rating scale scores and length of hospital stay in group I ( P>0.05). Conclusions:Individualized blood pressure management can reduce the development of postoperative delirium in elderly hypertensive patients undergoing radical resection for gastrointestinal tumor.

OBJECTIVE：To study the protective effects of butein on oxidative stress injury of PC12 cell and its effects on mitochondrial function. METHODS：Rats PC12 cells were divided into normal control group，model group，solvent control group（1 ‰ dimethyl sulfoxide），butein high，medium and low concentration groups（2，1，0.5 μmol/L）. The latter 4 groups were given relevant reagent/medicine for intervention；24 h later，other groups were given 100 mU/mL glucose oxidase to induce oxidant stress model except for normal control group. After 4 h culture，cell survival rate，apoptosis rate，the levels or activities of ROS，MDA，SOD，CAT，GSH-Px，ATP，IL-1β and TNF-α as well as the change of MMP were detected. RESULTS：Compared with normal control group，cell survival rate，the levels or activities of SOD，CAT，GSH-Px and ATP were all decreased significantly，and apoptotic rate，the content of ROS，the levels of MDA，IL-1β and TNF-α were all increased significantly（P＜0.05 or P＜0.01），while the MMP was decreased significantly. Compared with model group，above indexes of solvent control group had no significant change （P＞0.05），cell survival rates，the levels or activities of SOD （except for medium and low concentration groups），CAT，GSH-Px（except for medium and low concentration groups），ATP（except for low concentration group）were increased significantly in butein high，medium and low concentration groups，while apoptotic rates，the content of ROS，the levels of MDA，IL-1 β and TNF-α were decreased significantly（P＜0.05 or P＜0.01），while the MMP were increased significantly. CONCLUSIONS：Butein can increase the antioxidant enzyme activity， stabilize mitochondrial function， inhibit oxidative stress and inflammationthus， increase energy generation inhibiting neuronal cell apoptosis ultimately exerting a neuroprotective effect.