Objective:To construct a recombinant bioluminescent bacteriophage (HT7) targeting Escherichia coli, and evaluate its ability to identify Escherichia coli. Methods:Initially, pCRISPR-sg (1-10) and PFN-1000 plasmid strains were constructed by genetic engineering, and the most efficient small guild RNA (sgRNA) were screened by bilayer plate. By the gene editing technique, which comprised homologous recombination and clustered regularly interspaced short palin dromic repeats (CRISPR)-Cas system, the Nanoluc luciferase gene was integrated into the downstream non-coding region of 10A gene of T7 phage, to constructe the bioluminescent phage HT7 successfully. The difference of biological characteristics between HT7 phage and T7 phage was evaluated by plaque assay and liquid amplification assay. In addition, 51 strains of Escherichia coli, 20 strains of Klebsiella pneumoniae, 14 strains of Staphylococcus aureus, 6 strains of Enterococcus faecium, 5 strains of Enterococcus faecalis, 3 strains of Acinetobacter baumannii and 1 strain of Pseudomonas aeruginosa were collected and isolated to evaluate the limit of detection and specificity of HT7 phage. Results:Among the 10 CRISPR-targeted cleavage systems constructed, sgRNA8 exhibited the highest cleavage efficiency, with a cleavage rate of 0.18. After three rounds of recombination screening using the pCas9/pCRISPR/PFN-1000 triple-plasmid system, PCR validation yielded recombinant phage bands at 2 798 bp, indicating the successful construction of the HT7 phage. The recombinant phage showed significant differences in biological characteristics in terms of lysis efficiency ( P<0.001), one-step growth curve ( P=0.001), and infection multiplicity ( P=0.031). Both lysis burst time and log growth node were extended by 10 min, with the optimal infection multiplicity being 0.1. Clinical sample testing identified lysis of 6 strains of Escherichia coli within 4.5 h, while other strains remained unaffected, with detection of pathogenic bacteria below 10 CFU/ml. Conclusions:The developed pCas9/pCRISPR/PFN-1000 triple-plasmid editing system efficiently edits the bacteriophage genome. The constructed HT7 fluorescent bacteriophage enables the detection of Escherichia coli below 10 CFU/ml within 4.5 hours, demonstrating low detection limits and high detection specificity.

Objective To observe the effect of X-ray-guided placement of intestinal obstruction tube for treating malignant bowel obstruction(MBO)caused by gynecological malignant tumors.Methods Data of 60 patients with intestinal MBO after surgical operations of malignant gynecological tumors,including 30 cases underwent X-ray-guided intestinal obstruction tube placement(group A)and 30 cases underwent traditional nasogastric tube placement(group B),all followed by continuous gastrointestinal decompression were retrospectively analyzed.The remission of MBO symptoms,time of exhaust and defecation,so as diet recovery after treatment were compared between groups.The mean drainage volume within 24 h,tube retention time and treatment-related complications were recorded,and the survival of patients within 1 year after treatment were followed up.Results All 60 patients were successfully catheterized.The time of exhaust and defecation,oral feeding and tube retention time after catheterization in group A were shorter than those in group B(all P＜0.05),while the mean drainage volume within 24 h in group A was larger than that in group B(P＜0.05).No significant difference of relief rate of intestinal obstruction symptoms was found between groups(P=0.472).Minor nasal bleeding occurred in 8 cases,and oropharyngeal discomfort occurred in 4 cases in group A,while each in 5 cases in group B,all relieved without special treatments.No significant difference of treatment-related complication was observed between groups(P=0.361).One year after treatments,28 cases were followed up and 2 cases were lost in both groups,and no significant difference of survival rate was detected between group A(7/28,25.00%)and group B(5/28,17.86%)(P=0.745).Conclusion X-ray-guided placement of intestinal obstruction tube was safe and effective for treating MBO caused by malignant gynecological tumor.

Chylothorax is one of the complications of surgery and lymphatic diseases. The incidence rate of chylothorax has been increasing in recent years. X-ray-guided interventional therapy is a new method for treating chylothorax, and its curative effect is no less than the traditional surgical treatment. Based on discussing the aetiology and diagnosis of chylothorax, this paper briefly summarizes the application progress of X-ray-guided interventional therapy for chylothorax to provide further reference and a basis for clinical practice.

Objective:To analyze and summarize the causes of unscheduled suspension of knee and hip arthroplasty and to provide the method for optimizing the patient's pre-operative management and improving the efficiency of medical resources as well as the patient's satisfaction.Methods: The data for this report was retrospectively collected from September 2013 to August 2014 in our hospital,from cases of knee and hip arthroplasty that were suspended before the scheduled operation time.Acquisition data from the collected cases including the patients' gender,age and the surgical procedure.At the same time,the suspension reasons were recorded and analyzed.All the decisions of suspension was made by the surgeons and the anesthesiologists according to the abnormal result of preoperative examinations,after communicating with the patients and their families and obtaining their understandings.Results: In the collecting period,our department scheduled 1 146 cases of knee and hip arthroplasty,among which 1 003 were completed,143 suspended (12.5％ suspension rate).Among the causes of suspension,the top four common causes were cardiovascular disease (44/143,31％),other infections (20/143,14％),bacteriuria (18/143,13％) and inappropriate surgical indication (16/143,11％).Other causes include surgeon's reason,Blood system abnormalities,high inflammatory index,deep vein thrombosis,other diseases uncontrolled,abnormal liver function and poor diabetes mellitus control,etc.For the rate of suspension,there was no significant difference between the patients with different genders (male: 15.0％,and female: 11.7％,P=0.149),or age (≤50 years: 13.0％;51-65 years: 11.6％;66-80 years 13.3％;>80 years 11.1％;P=0.864).However compared with knee arthroplasty,hip arthroplasty had a higher suspension rate (knee arthroplasry 11.1％,hip arthroplasry 16.1％,P=0.021).Conclusion: It is important to educate and manage the patients before their knee and hip arthroplasty.Through clear diagnosis,detailed medical history analysis careful physical examination,and targeted outpatient examinations and tests for which priority was focused on cardiovascular or other system diseases we could minimize the occurrence of operative suspension post hospitalization,therefore improving the efficiency of the use of medical resources.

Objective:To compare the pain control efficiency of continuous adductor canal block (ACB) and femoral nerve block (FNB) in total knee arthroplasty.Methods:From April to September 2016,patients with severe knee osteoarthritis undergoing primary unilateral total knee arthroplasty (TKA) were prospectively observed,and all the patients were randomized received ultrasound-guided continuous ACB or FNB after surgery.Numeric pain rating scales (NPRS)pain scores in rest and activity 2,6,12,24 and 48 h after surgery were collected,and the preoperative and postoperative quadriceps strength at 24 and 48 h were analyzed.Opioids consumption and anesthesia related adverse effects were also recorded.Results:In the study,40 patients were enrolled,with 20 patients in each group,male ∶female =7 ∶ 33,the age:(63.8 ± 10.1) years,and the body mass index (BMI):(28.5 ± 3.5) kg/ m2.The general conditions were comparable between the two groups.Though the rest pain 2 h after surgery [ACB =0.0(0,6),FNB =3.0(0,5),P=0.004] and activity pain 12 h post operation [ACB =3.0(3,0),FNB =5.5(0,10),P =0.004] were lower in ACB group compared with FNB group,there was no statistical difference in the other pain checking points between the two groups.The quadriceps strength 24 h and 48 h after surgery were (85.3-± 27.6) N and (80.0 ± 30.1) N in ACB group,(69.0 ± 29.4) N and (64.4 ± 32.0) N in FNB group,both of them were declined by time.The exact data were higher in ACB group,however,there was no statistical difference between the two group by repeated measurements variance analysis(F =2.703,P =0.108).Four patients in ACB group and five in FNB acquired additional use of dolantin once (100 mg/per time) within 24 h.And among them,three patients acquired once dolantin in ACB,two in FNB,from 24 to 48 h postoperation.There were five patients who suffered nausea postoperation in ACB group,and one who reported xerostomia.Four patients in FNB had nausea with vomiting,and three experienced xerostomia.Deep vein thrombosis appeared in 2 patients in FNB group,but no one in ACB group.Conclusion:Continuous ACB is not superior in pain control after TKA compared with FNB,and the quadriceps strength could be reserved more by this method,which performed early benefits in fast rehabilitation.

Objective To compare the operative results of three kinds VATS on the treatment of young people with SP. Methods 108 young SP patients treated with VATS were involved in the research. 42 cases re?ceived three?port,35 cased double port and 31 cases uniport. Operation period,perioperative blood loss,time of intrathoracic drain tube,postoperative length of stay and postoperative pain were compared. Results No statistical difference was found in terms of operation duration between three?port VATS and double port VATS group (P >0.05). The postoperative pain in double port VATS and uniportal VATS lighter than uniportal VATS (P<0.05) . No statistical difference was found in terms of postoperative pain between double port VATS and uniport VATS group (P>0.05). Perioperative blood loss ,time of intrathoracic drain tube and postoperative length of stay showed no dif?ference in 3 groups (P>0.05). Conclusions Double port VATS has both the advantages of shorter operation time and lighter postoperative pain and was worth being popularized.

The continuing education system at the Peking University Health Science Center for vis-iting scholars (Research program for young and middle-aged doctors) is a relatively advanced and compre-hensive medical continuing education system in China, among which, the tutorial system is a good method to guide the visiting scholars of continuing education. On this basis we conducted scholars learning effect questionnaire survey and combined with the feedback results, discussed the advantages and disadvantages of the current educational system of visiting scholars in China, and put forward some concrete suggestions on the development of the continuing education in China.

Objective:To evaluate the efficiency of the tibial coronal alignment after total knee arthro-plasty with the extramedullary cutting system guided by the tibial tubercle and anterior tibial tendon,and to discuss the potential risk factors for the postoperative malalignment.Methods:A retrospective study of 212 primary unilateral TKA surgeries (in 188 patients)in our hospital between June to December in 2014 had been analysed.All the cases were performed by one surgical group.An extramedullary tibial cutting guide system had been used,with a landmark of one third inner-medial tibial tubercle as a proxi-mal anatomy reference,and anterior tibial tendon as a distal marker.The mechanical axis of lower ex-tremity in full-length X-ray was measured before surgery,and the tibial prosthetic coronal alignment was checked two weeks postoperation,evaluating the accuracy of this extramedullary cutting system guided by our method.Results:Since good alignment was defined as an angle within 3 degrees of the perpendicular to the mechanical axis,the tibial component positions were acceptable in 191 knees (90.1%),five knees were in valgus postoperative,and sixteen knees were in varus.There were seventeen(8.7%)in 179 knees with a preoperative varus presented malalignment after surgery,and four in 12 preoperative valgus kneess howed malalignment also,no statistical difference was found by Chi-square test (χ2 =2.778,P=0.096),which cannot define the relationship between the varus or valgus deformity preopera-tion and the malalignmentposition in tibial prosthesis after surgery.Twenty-two knees suffered a severe preoperative deformity as a varus or valgus angle larger than 20 degrees with absolute value of mechanical axis before surgery and tibial prosthetic coronal alignment were 21.95°(20.00°,26.90°)and 1.85° (0.10°,7.10°),showed a significant difference (Z =2.11,P =0.035 )compared with the data [10.65°(0.50°,19.80°)in preoperative mechanical axis and 1.10°(0.00°,4.60°)in the tibial pros-thetic coronal alignment]of 190 knees who presented a mild deformity before surgery(less than 20 de-grees),the result indicated the severe preoperative deformity might be a potential mal-alignment risk fac-tor within this cutting system in TKA surgery.Conclusion:The tibial coronal alignment after total knee arthroplasty could achieve good results with extramedullary cutting guide,by using one third inner-medial tibial tubercle and anterior tibial tendon as a proximal and distal anatomy marker.Postoperative varus might occur in this system,and tibial prosthetic malalignment appeared more often in the patients who suffered a severe deformity before surgery.

Toxascaris leonina is a common parasitic nematode of wild mammals and has significant impacts on the protection of rare wild animals. To analyze population genetic characteristics of T. leonina from South China tiger, its mitochondrial (mt) genome was sequenced. Its complete circular mt genome was 14,277 bp in length, including 12 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and 2 non-coding regions. The nucleotide composition was biased toward A and T. The most common start codon and stop codon were TTG and TAG, and 4 genes ended with an incomplete stop codon. There were 13 intergenic regions ranging 1 to 10 bp in size. Phylogenetically, T. leonina from a South China tiger was close to canine T. leonina. This study reports for the first time a complete mt genome sequence of T. leonina from the South China tiger, and provides a scientific basis for studying the genetic diversity of nematodes between different hosts.
Animals ; Animals, Wild ; Bias (Epidemiology) ; China* ; Codon, Initiator ; Codon, Terminator ; DNA, Intergenic ; Genes, rRNA ; Genetic Variation ; Genome ; Genome, Mitochondrial* ; Mammals ; Phylogeny ; RNA, Transfer ; Sequence Analysis* ; Tigers* ; Toxascaris*

Objective To explore the expression characteristic of T regulatory cell (Treg)/T help cell (Th)17 and the correlation to disease progression in chronic hepatitis B (CHB) patients undergoing antivirus treatment,and to explore their roles in pathogenesis of CHB.Methods A total of 53 patients with CHB (CHB group) and 21 healthy controls (healthy control group) were selected,CHB patients included mild 18 cases,moderate 16 cases and severe 19 cases.The expression of Treg and Th17 were detected by flow cytometry and compared.The levels of alanine aminotransferase (ALT),total bilirubin (TBIL),cholinesterase,albumin were measured by automatic biochemical machine and for correlation analysis.Results The levels ofTh17,Treg,Treg/Th17 were (2.13 ± 0.65)％,(2.99 ± 0.68)％ and (6.07 ± 1.18)％,(5.14 ± 0.96)％ and 2.86 ± 0.67,1.73 ± 0.45 in CHB group before and after treatment for 24 weeks and (3.59 ± 0.75)％,(4.02 ± 0.77)％,1.04 ± 0.34 in healthy control group.There were significant differences (F =14.78,10.12,17.19; P ＜ 0.01).The level of Th17 in mild,moderate and severe CHB was gradually decreased,but there was no significant difference (F =1.10,P =0.337).The level of Treg in mild,moderate and severe CHB patients was gradually increased,but there was no significant difference (F =0.54,P =0.585).The level of Treg/Th17 was gradually increased with aggravation (2.58 ± 0.59,2.76 ± 0.63,3.21 ± 0.71),and there was significant difference (F =3.15,P ＜ 0.01),the level of Treg/Th17 in severe CHB patients was significantly higher than that in mild,moderate CHB patients (P ＜0.05).The level of Treg/Th17 had significantly positive correlation with ALT,TBIL (r =0.272,P=0.000; r =0.226,P=0.000).Conclusion Treg/Th17 balance not only relates with the pathogenesis of CHB,but also with the related immune inflammatory of liver tissue.