As internal protein elements , inteins are self-excised from their host protein and catalyze ligation of exteins with a peptide bond .They are widely found in all the three domains of the biological kingdom , and in viral proteins .Intein-mediated protein splicing is a posttranslational autocatalytic process that does not require auxiliary enzymes or cofactors . Protein splicing involves four intramolecular reactions and a small number of key catalytic residues in the intein and exteins . The development of expressed protein ligation ( EPL ) and protein trans-splicing ( PTS ) is assisted by inteins and protein splicing.This review introduces the biosynthesis of backbone-cyclized peptides libraries , and describes the applications of cyclic polypeptides and their prospective applications in the future .

Objective To investigate the effectiveness and safety of dexmedetomidine combining with sufentanyl in controlling PCIA after laryngeal carcinoma surgery. Methods One hundred laryngeal carcinoma patients (ASAⅠorⅡ) were randomly assigned into 2 groups (n = 50, in each group). Group SF: sufentanil 0.04 mg/(kg·h)+dolasetron 12.5 mg; Group DE: dexmedetomidine 0.1 mg/(kg·h) +sufentani 0.02 mg/(kg· h) +dolasetron 12.5 mg, in which all drugs were dissolved in 100 mL 0.9% normal saline. Parameters: Infusion speed 2 mL/h; PCIA dosage 0.5 mL each time; monitor time: 15 min. PCIA were administrated after anesthesia recovery; BP, HR, SpO2, RR, RPP, pain and sedation score, side effect formation rate at 4、12、24、48 h after surgery were also recorded. Results MAP, RPP and HR in group DE were significant decreased compared with group SF at each time point,(P < 0.05); VAS scores had no significant difference between the two groups(P >0.05); Ramsay calm scores in group DE were significant better than that in group SF at each time point after surgery (P < 0.05); Frequency of nausea,vomiting and chills in group DE were significant lower than those in group SF (P < 0.05). Conclusion Small dose dexmedetomidine combination with sufentanil administration in PCIA after laryngeal carcinoma surgery could acquire satisfied analgesic effect , also could eliminate the patient anxious mood , enhance the security in the perioperative period and improve the patients' satisfaction degree , whichis very suitable for multi mode analgesia acquirement.

AIM:Todeterminetheeffectofsalviaextractonangiogenesisofthemyocardiumintheratswith myocardial infarction (MI) and to analyze its possible mechanism .METHODS: Left coronary artery of Sprague-Dawley rats was ligated to establish a MI model .The rats were randomly divided into MI model group , 3 different dose groups of salvia (10, 20 and 40 mg? kg-1? d-1), and sham operation group.Each group consisted of 8 rats.The rats in all treat-ment groups were orally administered with the salvia extract , and the rats in MI group and sham operation group were fed with the same volume of saline .The rats were sacrificed 4 weeks later .The hemodynamic changes of the rats were deter-mined , and the segmental heart samples were used for morphological observation by hematoxylin and eosin staining , Masson staining, or electron microscopic analysis.The expression of vascular endothelial growth factor (VEGF) and cluster of dif-ferentiation 34 ( CD34 ) was analyzed according to immunohistochemistry .RESULTS: Compared with sham operation group, the morphological changes of the myocardium in MI group were disordered , part of myocardial cell outline disap-peared , and obvious fibrosis in the necrosis myocardial tissue and fuzzy or disappearing microvascular ultrastructure were al -so observed .Compared with MI group , the number of new microvessels in all the treatment groups increased obviously , and the morphological changes of the endothelial cells were relatively complete according to electron microscopy .Compared with sham operation group , the protein expression of VEGF and CD 34 in the cytoplasm of the myocardial tissues in MI group in-creased only a little .Compared with MI group , the protein expression of VEGF and CD 34 in the cytoplasm of the myocardi-al tissues in all treatment groups increased significantly ( P<0.01 ) .CONCLUSION: Salvia extract obviously promotes angiogenesis of the myocardial tissues in the rats after myocardial infarction .

Objective To evaluate the efficacy and safety of actovegin against acute oral mucositis through a randomized controlled multicenter trial for nasopharyngeal carcinoma(NPC) patients treated by chemo-radiotherapy. Methods From February 2006 to May 2007,a total of 161 patients with newly diagnosed stage Ⅱ-ⅣA(1992 Fuzhou Stage) NPC were randomly assigned to the prevention group,the treatment group and the control group. All patients received current chemo-radiotherapy ± neoadjuvant chemotherapy. Radiation technique and dose were similar among the three groups. Intravenous infusion of aeovegin was started when radiation started in the prevention group and when grade 2 mueositis occurred in the treatment group,which was given 30 ml daily ,5 times per week until the end of radiotherapy. Criteria of NCI CTC 2.0 and VRS were used to evaluate acute oral mueositis and pain degree,respectively. Results 154 patients were eligible for the efficacy analysis,including 49 in the prevention group,53 in the treatment group and 52 in the control group. In the prevention group and the control group, the incidence was 31% and 56% (P=0.011) for grade 3-4 mucositis,59% and 83% (P=0.009) for grade 2-3 pain. In the treatment group and the control group,the corresponding number was 38% and 60% (P=0.023) ,70% and 90%, (P=0.014). The prevention group had a lower incidence(P=0.021) and longer average interval(P=0.009) of grade 2 mucositis when comparing with the control group. No drug-related adverse event was observed. Conclusions Prophylactic or therapeutic use of actovegin by intravenous infusion can significantly reduce the severity of ehemo-radiotherapy induced oral mucositis and pain. The prophylactic use may also postpone and decrease the incidence of grade 2 mucositis,which deserves clinic application.

Critical care medicine has developed rapidly and has become an indispensable comprehensive subject in clinical medicine at home and abroad.In recent years,the government has vigorously implemented the "Healthy China" strategy and strived to achieve a higher level of national health.The Henan Provincial People's Hospital has set up a network of interconnected "Wisdom · Critical Care Medicine Specialist League" to meet the major strategic needs of the country,and to play a role in attracting large hospitals to promote the sinking of quality medical resources and the improvement of grassroots service capabilities.Complementary advantages and resource sharing are conducive to achieve win-win cooperation and coordinated development between the third-grade class-A hospital and grassroots hospitals.

Objective To explore the effect of astragalus extracts on adherence, migration, cell viability, microvascular formation, and eNOS expression in bone marrow-derived endothelial progenitor cells (EPCs) of rats. Methods EPCs were cultured, isolated and identified in vitro and divided into four groups: low titer group (10-4 g/L of astragalus extracts), middle titer group (10-3 g/L of astragalus extracts), high titer group (10-2 g/L of astragalus extracts) and control group. The effects of astragalus extract on adhesion, migration or microvascular formation were observed under the inverted microscope and com?pared between all groups;Cell viability was detected by MTT assay;mRNA transcription and protein expression levels of en?dothelial nitric oxide synthase (eNOS) in EPCs were detected by reverse transcription PCR (RT-PCR) and Western blot re?spectively. Results Compared with the control group, cell adhesion, migration and microvascular formation of EPCs all en?hanced with addition of astragalus extracts in a dose dependent manner (F=15.256, 13.633, 97.549 respectively, and P <0.05 in all cases); Cell vitality of EPCs increased with administration of astragalus extracts in a time and dose dependant manner. (F=9.755 for time and F=10.18 for dose). mRNA transcription and protein expression of eNOS in EPCs were up-reg?ulated with addition of astragalus extracts in a dose dependent manner (F=56.356 and 77.125 respectively, and P<0.05 in both cases). Conclusion Astragalus extracts play important role in angiogenesis in EPCs probably through up-regulating expressions of eNOS.

Objective To investigate the influence of“double low”technology(low concentration iodinated contrast agent and low-dose scan) combined with body mass index(BMI) on radiation dose and image quality of contrast-enhanced upper abdominal CT examination. Methods One hundred and twenty patients who received upper abdominal enhanced CT examination were randomly divided into 4 groups:group A1, the iodinated contrast agent iodixanol(270 mg/ml), BMI<18.5 kg/m2 and 80 kVp;group A2, the iodinated contrast agent iodixanol(270 mg/ml), 18.5 kg/m2≤BMI≤24.9 kg/m2 and 100 kVp; group B1, the iodinated contrast agent ioversol(320 mg/ml),<18.5 kg/m2 and 120 kVp; group B2, the iodinated contrast agent ioversol(320 mg/ml), 18.5 kg/m2≤BMI≤24.9 kg/m2 and 120 kVp. Image quality was subjectively scored, the objective parameters(noise, CT values of abdominal aorta and liver parenchyma, contrast noise ratio of abdominal aorta and liver parenchyma) were evaluated and radiation dose was recorded. The differences of the indexes between A1 and B1 groups, A2 and B2 groups were compared with Mann-Whitney U test and pared-samples t test. Results All CT images were good. No images with 4 scores were obtained. No significant difference was found between group A1 and B1, between group A2 and B2(P>0.05). There was no significant difference in contrast noise ratio of liver parenchyma(P>0.05), while significant differences existed in CT values of abdominal aorta and liver parenchyma, contrast noise ratio of abdominal aorta between group A1 and B1(P<0.05). Significant differences existed in the parameters above mentioned between group A2 and B2, respectively(P<0.05). Radiation dose was lower in group A1 than in group B1 and in group A2 than in group B2(P<0.05), respectively. Radiation dose was decreased by 40.1%(0.89/2.22) in group A1 than group B1 while radiation dose decreased by 56.9%(3.02/5.31) in group A2 than group B2. Conclusion According to BMI, the low concentration iodinated contrast agent and low-dose scan CT scanning technology could effectively reduce radiation dose and generate ideal images during the contrast-enhanced upper abdominal CT examination.

Aim To explore the effect of protein kinase D1 (PKD1 )on adherence,migration,proliferation, microvascular formation,and eNOS expression in bone marrow-derived endothelial progenitor cells(EPCs)of rats.Method The EPCs were isolated from bone marrow of rats,cultured and detected,the effects of PKD1 and its specific blocking agent CID755673 on adhesion,migration,proliferation,or microvascular formation were observed,as well as mRNA and protein expression of endothelial nitric oxide synthase (eNOS ) in EPCs.Results PKD1 significantly promoted adhe-sion,migration,proliferation and microvascular forma-tion of EPCs,and upregulated the mRNA and protein expression of eNOS in EPCs,according to the cell cul-ture experiments of EPCs in vitro.Conclusion PKD1 has the role of angiogenesis through regulation of EPCs,which might be dependent on eNOS.

Objective To study the phylogenetic evolution and genetic variations of gag gene among the prevalent human immunodeficiency virus (HIV )‐1 strains in Guangxi Zhuang Autonomous Region . Methods Plasma samples of 158 HIV‐1 infected patients in Guangxi area were collected during October 2011 to March 2012 .The gag gene fragments of HIV‐1 were amplified by reverse transcription/nested‐polymerase chain reaction and then sequenced .MEGA 5 .03 was utilized to construct phylogenetic tree and to calculate the genetic distances and selection pressures (globle ω) of gag gene and its coding regions . The comparisons between two groups were tested by Student′s t test ,and the comparisons of multiple groups were tested by one‐way ANOVA .Results A total of 140 amplification products of gag gene were obtained from 158 samples .Four subtypes of HIV‐1 were found ,including CRF01_AE (80 ,57 .1% ) , CRF08_BC (46 ,32 .9% ) ,CRF07_BC (10 ,7 .1% ) ,and subtype B (B′) (4 ,2 .9% ) .The genetic distances of gag gene of the above subtypes were 0 .036 ± 0 .001 ,0 .031 ± 0 .002 ,0 .043 ± 0 .003 and 0 .102 ± 0 .006 ,respectively ,with statistical significance (F=220 .62 ,P<0 .01) .The p17 and p24 coding regions suffered negative selection pressure (globleω<1) .Neither the globle ω in p17 region nor that in p24 region had significant differences among different subtypes (F=0 .761 ,P=0 .469 and F=0 .037 ,P=0 .964 , respectively ) . Conclusion CRF01_AE is the major subtypes of HIV‐1 in Guangxi Zhuang Autonomous Region .The coding regions of gag gene are relatively conserved during evolution .Changes of HIV‐1 prevalence ,however ,may affect the genetic variation of gag gene ,which should be continuously monitored .

Objective To design and construct a new non-fusion soluble expression vector pTIG-mSUMO(small ubiq-uitin-related modifier) using the widely used solubility promoting protein SUMO and based on the translational coupling phenomenon in order to enable the non-fusion soluble expression of the broad-spectrum antiviral protein RA in Escherichia coli by pTIG-mSUMO.Methods The smt3 gene coding for SUMO protein was cloned from yeast genome DNA by PCR. After directed-site silent mutation to eliminate the EcoRⅠsite, the mutant mSUMO was inserted into pET-22b to obtain the translational coupling expression vector pTIG-mSUMO.The RA was subject to PCR amplification and cloned into the pTIG-mSUMO to obtain the expression plasmid pTIG-mSUMO/RA which was supposed to direct the soluble expression of RA by the translational coupling with mSUMO.Results A translational coupling expression vector pTIG-mSUMO which could di-rect/drive the SUMO and heterogonous protein non-fusion expression simultaneously was designed and constructed.The Western blotting result indicated that pTIG-mSUMO could direct the high-level expression of RA, around 40%of which was soluble.Conclusion A translational coupling expression vector pTIG-mSUMO is obtained.After coupling with SUMO, RA is highly expressed in E.coli and both the expression level and solubility are greatly improved.pTIG-mSUMO might contrib-ute to soluble expression of other proteins.