Semi-rational evolution of ω-transaminase from Aspergillus terreus for enhancing the thermostability / 生物工程学报

ω-transaminase (ω-TA) is a natural biocatalyst that has good application potential in the synthesis of chiral amines. However, the poor stability and low activity of ω-TA in the process of catalyzing unnatural substrates greatly hampers its application. To overcome these shortcomings, the thermostability of (R)-ω-TA (AtTA) from Aspergillus terreus was engineered by combining molecular dynamics simulation assisted computer-aided design with random and combinatorial mutation. An optimal mutant AtTA-E104D/A246V/R266Q (M3) with synchronously enhanced thermostability and activity was obtained. Compared with the wild- type (WT) enzyme, the half-life t1/2 (35 ℃) of M3 was prolonged by 4.8-time (from 17.8 min to 102.7 min), and the half deactivation temperature (T1050) was increased from 38.1 ℃ to 40.3 ℃. The catalytic efficiencies toward pyruvate and 1-(R)-phenylethylamine of M3 were 1.59- and 1.56-fold that of WT. Molecular dynamics simulation and molecular docking showed that the reinforced stability of α-helix caused by the increase of hydrogen bond and hydrophobic interaction in molecules was the main reason for the improvement of enzyme thermostability. The enhanced hydrogen bond of substrate with surrounding amino acid residues and the enlarged substrate binding pocket contributed to the increased catalytic efficiency of M3. Substrate spectrum analysis revealed that the catalytic performance of M3 on 11 aromatic ketones were higher than that of WT, which further showed the application potential of M3 in the synthesis of chiral amines.

Profile and inspirations of learning health system abroad / 中华医院管理杂志

As a platform to learn authentic patient experiences, learning health system(LHS)acquires big data from clinical environment and other health-related events, analyzes data to produce new knowledge and applies these knowledge to constantly guide clinical decision and practice, thus contributing effectively to better quality of care and lower medical cost. The authors reviewed LHS in terms of its role model, organizational structure, infrastructure framework, core characteristic elements framework and researcher′s core competence framework. Based on the study, the authors recommended the integration of multi-source heterogeneous medical information platform data, and enhancement of synergy among medical institutions and multi-disciplinary teams in the introduction and localization of LHS into China.

The influence of sarcopenia on postoperative complications and its interventions in the elderly patients / 中华老年医学杂志

Sarcopenia is a common degenerative disease that often occurs in the elderly.It not only increases the risks of falling down and disability in the elderly patients, but also is related to the adverse outcome after operation.The early diagnosis and early intervention are of great clinical significance for improving the postoperative situation and increasing the survival rate of the patients.Based on the latest literature, this paper illustrates in detail the diagnosis of sarcopenia, its influences on postoperative complications, and perioperative clinical interventions in the elderly patients.

Software-aided detection and structural characterization of cyclic peptide metabolites in biological matrix by high-resolution mass spectrometry / 药物分析学报

Compared to their linear counterparts, cyclic peptides show better biological activities, such as anti-bacterial, immunosuppressive, and anti-tumor activities, and pharmaceutical properties due to their conformational rigidity. However, cyclic peptides could form numerous putative metabolites from po-tential hydrolytic cleavages and their fragments are very difficult to interpret. These characteristics pose a great challenge when analyzing metabolites of cyclic peptides by mass spectrometry. This study was to assess and apply a software-aided analytical workflow for the detection and structural characterization of cyclic peptide metabolites. Insulin and atrial natriuretic peptide (ANP) as model cyclic peptides were incubated with trypsin/chymotrypsin and/or rat liver S9, followed by data acquisition using TripleTOF? 5600. Resultant full-scan MS and MS/MS datasets were automatically processed through a combination of targeted and untargeted peak finding strategies. MS/MS spectra of predicted metabolites were interrogated against putative metabolite sequences, in light of a, b, y and internal fragment series. The resulting fragment assignments led to the confirmation and ranking of the metabolite sequences and identification of metabolic modification. As a result, 29 metabolites with linear or cyclic structures were detected in the insulin incubation with the hydrolytic enzymes. Sequences of twenty insulin metabolites were further determined, which were consistent with the hydrolytic sites of these enzymes. In the same manner, multiple metabolites of insulin and ANP formed in rat liver S9 incubation were detected and structurally characterized, some of which have not been previously reported. The results demonstrated the utility of software-aided data processing tool in detection and identification of cyclic peptide metabolites.

Identification and homology analysis of Ochrobactrum-like species infection in bloodstream of children / 临床检验杂志

Objective To identify and analyze the homology of Ochrobactrum isolated from clinical blood samples of children.Methods The 26 strains of Ochrobactrum anthropi were identified by Vitek 2 Compact and test strips of API 20 NE bacterial identification system.The biochemical phenotypes were identified by manual tests.The 16S rRNA and recA gene were amplified by PCR and sequenced.The drug sensitivity tests of Ochrobactrum anthropi were performed by Vitek 2 Compact and matched GN13 card.The homology was analyzed by pulsed field gel electrophoresis.Results Based on the identification of the instruments and the manual tests for biochemical phenotype,all the 26 experimental strains were Ochrobactrum anthropi.The results of sequencing for 16S rRNA and recA gene amplification products showed 25 strains were Pseudochrobactrum saccharolyticum and the other 1 was O.grignonensein.Drug sensitivity analysis showed that the all the 26 strains were resistant to aztreonam,but the sensitive rates to quinolones,aminoglycosides,trimethoprim sulfamethoxazole,four generation of cephalosporins and the antibiotics compound of piperacillin/tazobactam were all more than 80％.Pulsed field gel electrophoresis analysis showed that the 25 strains were highly homologous with differences of only 1 to 3 bands in fingerprint profiles.Conclusion Based on the biochemical phenotype and the sequencing of 16S rRNA and recA gene,the Ochrobactrum-like bacteria could be identified to the level of species.The highly homologous strains of Pseudochrobactrum saccharolyticum may be sourced from a clustered infection.

Hemostatic effect of carboxymethyl chitosan and its biosecurity properties / 中国组织工程研究

BACKGROUND:Carboxymethyl chitosan (CMCS),a chitin derivative,has a good application performance that makes it become a safe and effective hemostatic material.OBJECTIVE:To determine the hemostatic effect of CMCS and its biosecurity properties.METHODS:(1) CMCS powder was scattered on the caudal vein and liver wounds of Sprague-Dawley rats,and the hemostatic time was recorded as experimental group,while the time for natural haemostasis of the wound was recorded as control group.(2) CMCS powder was scattered on the tail,femoral artery and liver wounds of ICR mice,and the hemostatic time was recorded as experimental group,while the time for natural haemostasis of the wound was recorded as control group.(3) CMCS,Sodium dodecyl sulfate solution and distilled water were respectively applied on the skin of albino rabbits in a skin irritation test.(4) A delayed-type hypersensitivity test of CMCS was carried out by intradermal injection of CMCS in guinea pigs.(5) An intradermal irritation test was carried out by subcutaneous injection of normal saline containing CMCS and normal saline,respectively.Another intradermal irritation test was carried out by subcutaneous injection of the supernatant of CMCS olive oil extract and olive oil,respectively.RESULTS AND CONCLUSION:(1) Compared with the control group,the hemostatic time for caudal vein and liver wounds were significantly shortened in the Sprague-Dawley rats in the experimental group (P ＜ 0.01).(2) Compared with the control group,the time of hemostasis on the tail,femoral artery and liver wounds was significantly shortened in the ICR mice in the experimental group (P ＜ 0.05 or P ＜ 0.01).(3) The CMCS had no irritation to the skin of albino rabbits and no allergic reaction to the skin of guinea pigs.To conclude,the CMCS has good hemostatic effect on the wound in Sprague-Dawley rats and ICR mice,and has no skin irritation,allergic reactions and intradermal irritation reactions in albino rabbits and guinea pigs,which is a relatively safe hemostatic material.

Effects of penehyclidine hydrochloride injection combined with safflower injection on TLRs / NF-κB signaling pathway and T cell subsets in mononuclear cells of patients with organophosphorus pesticide poisoning / 中国生化药物杂志

Objective To investigate the effects of penehyclidine hydrochloride injection combined with safflower injection on TLRs/NF-κB signaling pathway and T cell subsets in mononuclear cells of patients with organophosphorus pesticide poisoning. Methods 80 cases of organophosphate poisoning patients from June 2014 to June 2016 in onglu first people's hospital were selected,randomly divided into control group and observation group, the control group was treated with penehyclidine hydrochloride,observation group were treated with Honghua injection based on the treatment of control group. The effects were compared between two groups of TLRs/NF-κB in peripheral blood mononuclear cells pathway and T cell subsets in peripheral blood, and compared two groups of patients with cholinesterase activity. Results On the third,fifth and 7th day of treatment,cholinesterase activity in both groups was higher than that before treatment,the activity of cholinesterase in the observation group was significantly higher than that in the control group (P<0.05).After treatment,compared with before treatment,the levels of TLR2,TLR4 and NF-κB in the two groups were significantly decreased,and TLR2,TLR4,NF-κB levels in the observation group were lower than those in the control group, the difference was statistically significant (P<0.05),Th17,Th17/Treg levels in the observation group were significantly lower,and lower than the control group,Treg content was significantly higher,and higher than the control group,the difference was statistically significant (P<0.05). Conclusion Penehyclidine hydrochloride injection combined with safflower injection can help to reduce Th17,Th17/Treg levels,increased Treg cell content,regulate the inflammatory response, and promote recovery of cholinesterase activity.

Analysis on interference effects of vitamin C on three kinds of glucose detection methods / 国际检验医学杂志

Objective To investigate the interference effects of vitamin C on three different detection methods of blood glucose.Methods According to CLSI EP7-A2 document,5% volume of vitamin C(series concentrations) solution was added to fresh mixed serum,then hexokinase method(A),glucose oxidase method(B) and glucose reductase electrode method(C) were used to detect the level of fresh mixed serum glucose.The interference level of vitamin C on three different detection methods of blood glucose was evaluated.Results In 1 250 mg/L vitamin C,there was no interference on the method A for detecting blood glucose.In 156 mg/L vitamin C,it caused unacceptable negative interference on the method B and unacceptable positive interference on the method C.Moreover the interference degree of these two methods was increased with vitamin C concentration increase,but the same concentration of vitamin C had no significant difference on detecting different blood glucose levels by the same detection method.Conclusion High concentration of vitamin C can cause significant interference on glucose detection by glucose oxidase method and glucose reductase electrode method.

Early diagnostic value of relevant platelet parameters and thrombelastogram detection for diabetic patients with angiopathy / 国际检验医学杂志

Objective To investigate the relationship between the relevant platelet parameters and the thromboelastographic in-dexes with the the occurrence and development of diabetic vascular complications so as to early find the high-risk group of vascular complications or early patients .Methods According to the WHO diagnostic criteria for diabetes ,268 patients with diabetes and 80 retired people with the physical examination (normal control group) were selected as the research subjects .268 cases were divided into the group A(HbA1c 6 .5% without vascular complications) and the group C(HbA1c >8 .0% with vascular complications ) .The Siemens ADVIA2120 fully automatic blood analyzer was adopt-ed to detect the platelet parameters of mean platelet volume (MPV) ,platelet distribution width(PDW) ,large-platelet(L-PLT) , MPM and mean platelet concentration(MPC);The TEG@ 5000 coagulation analyzer was adopted to perform the thromboelastogra-phy for detecting the values of R ,K ,Angle A and MA .All obtained data were statistically analyzed .Results L-PLT in the group B and the platelet parameters in the group C had statistical differences compared with the normal control group (P<0 .05) .The val-ues of R ,K ,Angle A in the group B and the values of R ,K ,Angle A and Ma in the group C had statistical differences compared with the normal control group (P<0 .05) .Conclusion Relevant platelet parameters and the thrombelastogram detection have the important significance to help to the clinical diagnosis of diabetic angiopathy ,guide the treatment and the condition monitoring ;the thrombelastogram is more sensitive than the detection of the relevant platelet parameters in early finding the patients with diabetic angiopathy .