In modern biology and biotechnology research, recombinant gene expression has been the most popular method to obtain the target protein. In recent years, many foreign genes have been efficiently expressed in Escherichia coli. However, proteins encoded by animal, plant or mesophilic microbial genes often lose activities or become denatured within a few hours at regular growth temperatures for E. coli; some other target proteins are toxic to host cells and therefore difficult to be over-expressed. The new T-vector, pEXC-T, was constructed by combining TA cloning and cold-shock induction to obtain high expression levels with low costs. This paper reports the construction of pEXC-T and optimization of induction techniques for gene expression. Two instable proteins were tested and successfully expressed in soluble form by using pEXC vector. The development of pEXC-T offers a convenient technique for the preparations of recombinant proteins to be used in structure/function studies, or as diagnostic markers and medicinal proteins.
Biotechnology ; Cold Temperature ; Escherichia coli ; genetics ; Gene Expression ; Genetic Vectors ; Plasmids ; genetics ; Recombinant Proteins

Objective To retrospectively review the experience of anesthesia for aortic valve insufficiency complicated with extremely dilated left ventricle.Methods The patients were premedieated with morphine 10 mg and scopolamine 0.3 mg IM.Anesthesia was induced with etomidate 0.1-0.2 ms/ks.sufentanil 1μ/kg and pipecuronium 0.1 mg/kg.After the patients were intubated,anesthesia wag maintained beween 1.0%and 1.5% isoflurane and intermittent Ⅳ boluses of sufentanil and pipecuronium.ECG,direct BP,SpO2,PET CO2,CVP and body temperature were monitored during anesthesia.Result All patients Were rehabilitated without ventricular fibrillation and arrhythmia.Conlusions Measures are taken before the surgery to maintain preload,increase heart rate,reduce afterload moderately and maintain myocardial contractility.After the surgery,maintenance of preload is helpful for ensuring adequate forward flow and benefcial to patients using dopamine and nitrolycerin.

IL-18, as a polyphonic cytokine, is important in immune response and physiologic function. We designed one pair of primers, amplified the porcine IL-18 gene fused with a C-terminal 6xHistidine tag, and then subcloned into the pFastBacDual of Baculovirus transfer vector and transformed into DH10Bac containing a shuttle vector of Bacmid. After co-transfecting the recombinant plasmid into insect cells, the 18 kDa expressed protein of porcine IL-18 was detected by SDS-PAGE; the specificity of expressed protein was confirmed by Western blotting. The purified porcine IL-18 protein induced obvious proliferation of porcine T lymphocytes in vitro, which indicated that the expression of IL-18 had high biological activity.
Animals ; Baculoviridae ; genetics ; metabolism ; Cells, Cultured ; Genetic Vectors ; genetics ; Insecta ; genetics ; metabolism ; Interleukin-18 ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Swine ; Transfection

Objective:To evaluate the feasibility and clinical effectiveness of placing a nasointestinal ileus tube (NTI) during extensive adhesive bowel obstruction (ABO) surgery.Methods:A retrospective analysis was performed for the clinical and follow-up data of 60 patients with extensive ABO admitted to the Department of General Surgery of Daxing District Hospital of Capital Medical University from April 2019 to April 2021, of which 30 patients underwent intraoperative NIT intraintestinal alignment (observation group) and 30 patients who did not undergo NIT intraintestinal alignment (control group) during the same period. There were 12 males and 18 females in the observation group. There were 16 males and 14 females in the control group. The operation time, gastrointestinal function recovery time, discharge time, total effective rate and postoperative complication rate were compared between the two groups, and the quantitative data of the recurrence rate of intestinal obstruction at 24 months after surgery were expressed as mean ± standard deviation ( ± s), and the t-test was used for comparison between groups. Numerological data were presented as cases (percentage) [ n (%)], and chi-square tests were used for comparison between groups. Results:All patients were successfully completed the surgery and discharged from the hospital. There was no statistically significant difference in total effective rate between the control group and the observation group( χ2=3.16, P=0.237). The surgical time in the observation group was slightly longer than that in the control group [(110.6±4.6) min vs (94.3±2.5) min, t=17.27, P=0.001]. The recovery time of gastrointestinal function and hospitalization time in the observation group were shorter than those in the control group[(8.13±1.00) d vs (8.70±0.70) d, t=2.53, P=0.014; (12.83±1.57) d vs (13.67±1.03) d, t=0.03, P=0.018]. The incidence of postoperative complications was lower than that in the control group (10% vs 30%, P=0.028), and the difference was statistically significant. Conclusion:Intraoperative application of NIT is safe and effective, and can significantly reduce the recurrence rate of postoperative intestinal obstruction.

Objective:To investigate the associations of articular depression depth (ADD) and tibial plateau widening (TPW) by pre-operative CT measurement with incidence of lateral meniscal tear in patients with Schatzker type Ⅱ tibial plateau fracture.Methods:Included in this retrospective study were 131 patients who had been admitted to Emergency Center of Trauma, The Third Hospital Affiliated to Hebei Medical University from January 2016 to January 2020 for Schatzker type Ⅱtibial plateau fractures. They were 88 males and 51 females, aged from 18 to 60 years (average, 41.5 years), with 74 right and 57 left sides injured. All patients were treated with closed reduction and internal fixation assisted by bidirectional traction. Arthroscopy was used to detect the status of lateral meniscus immediately after closed reduction and internal fixation of the fracture fragments. Furthermore, patients were divided into 2 groups according to the integrity of lateral meniscus: meniscal tear group ( n=70) and tear-free group ( n=61). The 2 groups were compared in terms of age, gender, body mass index(BMI), injury side, time interval from injury to surgery, TPW and ADD. The receiver operating curve (ROC) was drafted to calculate the cut-off values of TPW and ADD in complication of lateral meniscal tear in patients with Schatzker type Ⅱ tibial plateau fracture. Results:The overall incidence of lateral meniscal tear in this cohort was 53.4% (70/131). There was no statistically significant difference in terms of age, gender, injury side, BMI or time interval from injury to surgery between the 2 groups ( P>0.05); TPW and ADD were significantly higher in the meniscal tear group than in the tear-free group ( P<0.05). To predict lateral meniscal tear in patients with Schatzker type Ⅱtibial plateau fracture, the area under ROC was 0.656 (95% CI: 0.562 to 0.750, P=0.002) for TPW and 0.709 (95% CI: 0.619 to 0.800, P<0.001) for ADD, respectively; the cut-off values of TPW and ADD were 4.3 mm and 6.1 mm. Conclusion:TPW and ADD may be effective predictors for prediction of lateral meniscal tear in patients with Schatzker type Ⅱ tibial plateau fracture.

Objective To compare and analyze the epidemiological features of adult patients with scapular fracture between eastern and western areas in China from 2010 to 2011. Methods The data of adult patients with scapular fracture who had been treated from January 2010 to December 2011 in 63 hospitals in the eastern and western areas in China were collected through the PACS system and case reports checking system. The data from the eastern 35 hospitals were classified as group A and those from the 28 western hospitals as group B. The analytic items included gender, age and AO classification. Results A total of 2, 063 cases were collected. The median age was 44 years ( interquartile range, from 33 to 56 years ) and gender ratio 3. 50:1 in Group A of 1, 376 cases; the median age was 41 years ( interquartile range, from 31 to 51 years ) and gender ratio 3. 09:1 in Group B of 687 cases. There was a significant difference between the 2 groups in median age ( Z= -3. 798, P=0. 000 ) . There was no significant difference between the 2 groups in gender ratio or constituent ratio of fracture peak age ( P > 0. 05 ) . The proportions of patients from 16 to 20 and from 31 to 40 years old in group A were significantly lower than in group B ( P <0. 05 ) . The proportion of middle-aged patients was significantly higher and that of young patients significantly lower in group A than in group B. The proportion of AO type 14-A fractures in group A ( 66. 49％) was significantly higher than in group B ( 55. 60％) while the proportion of AO type 14-C fractures was significantly lower ( 21. 37％) in group A than in group B ( 29. 55％) . Conclusions Most scapular fractures occurred in male patients. The proportion of young patients in the eastern area was lower than in the western area, but the proportion of middle-aged patients was higher in the eastern area than in the western area. The proportion of AO type 14-A fractures in the eastern area was significantly higher than in the western area while the proportion of AO type 14-C fractures in the eastern area significantly lower than in the western area.