Objective To investigate the clinical features of aortic dissection (AD) and emergency treatments. Methods Data from 784 patients with aortic dissection were collected in the Department of Emergency from January 2000 through December 2009. A retrospective analysis was carried out to determine the survival rate, mortality rate and treatment efficiency. Results Pain was the most common onset symptom (77.7% , 609/784). The majority of patients (86.5%) had essential hypertension (678/784). All the patients with preoperative diagnosis of aortic dissection underwent emergency medical intervention by internists resulting in 81.5% survival rate (639/784) and 18.5% mortality rate (145/784). There were 157 patients without improvement (20.0% ) and the total efficiency rate was (83. 1% ). The efficiency rate of conventional treatment was 76.4% , while the efficiency rate of triple four-procedure treatment was 89. 8% (P<0.05). Of them, 139 patients (17. 7% ) died in the hospital. Among them,. 26 patients died within 24 hours (18.4% ) and 47 cases died within 48 hours (33. 8% ) and 66 patients died within 72 hours (47.2% ). There were 92 patients who refused treatments after diagnosis, and among them, 81 patients died within 72 hours (88.04% ). The difference in mortality rate between two groups was significant (P<0.05). Conclusions The diagnosis of aortic dissection depends on detailed history, physical examination and CT or MRI imaging. Analgesia, sedation and control of blood pressure are essential for emergency treatments. Early diagnosis and effective emergency treatments are the critical strategy for the early surgical intervention and time window for further treatment to improve the survival rate of AD.

In order to overcome the challenges of insufficient restriction enzyme sites, and construct a fusion-expression vector with flexible fusion direction, we designed an LB cloning system based on the type IIS and type IIT restriction enzymes LguⅠ and BbvCⅠ. The LB cloning system is constructed by inserting the LB fragment (GCTCTTCCTCAGC) into the multiple cloning site region of the broad-host plasmid pBBR1MCS-3 using PCR. The LB fragment contains partially overlapped recognition sites of LguⅠ and BbvCⅠ. Therefore, the same non-palindromic sequence will be generated by these two restriction endonucleases digestion. This feature can be used to quickly and flexibly insert multiple genes into the expression vector in a stepwise and directed way. In order to verify the efficacy of the cloning system, two glycosyltransferase genes welB and welK of Sphingomonas sp. WG were consecutively fused to the LB cloning vector, and the recombinant plasmid was transferred into Sphingomonas sp. WG by triparental mating. The results showed that gene fusion expression has little effect on sphingan titer, but enhanced the viscosity of sphingan. The viscosity of the sphingan produced by recombinant strain Sphingomonas sp. WG/pBBR1MCS-3-LB-welKB was 24.7% higher than that of the wild strain after fermentation for 84 h, which would be beneficial for its application. In conclusion, the application of LB cloning system were verified using Sphingomonas sp. WG. The LB cloning system may provide an efficient tool for fusion expression of target genes.
Base Sequence ; Cloning, Molecular ; Fermentation ; Plasmids/genetics* ; Sphingomonas/metabolism*