ABSTRACT
Objective To explore the predictive value of plasma cell-free DNA (cf-DNA) for prognosis in patients with sepsis. Methods 105 patients with sepsis admitted to department of emergency of the First Hospital of Quanzhou Affiliated to Fujian Medical University from June 2015 to June 2017 were enrolled. Patients were divided into sepsis group (n = 50) and severe sepsis group (n = 55). At the same time, 50 cases of physical examination center in our hospital were randomly selected as the healthy control group. The differences of cf-DNA, procalcitonin (PCT) and acute physiology and chronic health evaluation Ⅱ(APACHEⅡ) score among the three groups were compared. The correlation between cf-DNA and PCT or APACHEⅡ were analyzed by Bivarite method. Logistic regression was used to analyze the independent predictors of sepsis. The receiver operating characteristic curve (ROC) was made to evaluate cf-DNA, PCT, APACHEⅡ alone or combined ability to predict the prognosis of sepsis. Results The PCT, APACHE Ⅱ and cf-DNA in the sepsis group and severe sepsis group were significantly higher than those in the healthy control group [PCT (μg/L):5.80 (3.28, 8.85), 17.53 (8.40, 29.61) vs. 0.02 (0.01, 0.03); APACHEⅡ: 13.04±3.03, 23.29±8.02 vs. 2.10±1.05;cf-DNA (μg/L): 1 438.0 (1 154.0, 1 576.0), 2 595.0 (2 162.0, 5 198.0) vs. 17.0 (13.0, 20.5); all P﹤0.05], and the indicators in the severe sepsis group were further higher than the sepsis group (all P < 0.05). Correlation analysis showed that cf-DNA was significantly positive correlated with PCT [r = 0.675, 95% confidence interval (95%CI) = 0.575-0.766, P < 0.001] and APACHEⅡ (r = 0.911, 95%CI = 0.874-0.939, P < 0.001). ROC curve analysis showed that the areas under ROC curve (AUC) of PCT, APACHEⅡ, cf-DNA, PCT+APACHEⅡ, cf-DNA+PCT, cf-DNA+APACHEⅡ, cf-DNA+PCT+APACHEⅡ to predict the prognosis of sepsis patients were 0.898, 0.905, 0.961, 0.941, 0.974, 0.976 and 0.982, respectively. It was shown that when predicted alone with PCT, APACHEⅡ and cf-DNA, the AUC of cf-DNA was the largest (0.961), the sensitivity was 100%, and the specificity was 81.43%; the combined prediction of cf-DNA with PCT or APACHEⅡ could further increase AUC, and the combined prediction of cf-DNA, PCT and APACHEⅡhad the highest AUC (0.982), the sensitivity was 94.29%, the specificity was 98.57%. Conclusions cf-DNA, PCT and APACHEⅡ have certain predictive value for the prognosis of sepsis. The value of cf-DNA was the highest when predicted alone, but the predictive ability of cf-DNA combined with PCT and APACHEⅡ was the best.
ABSTRACT
BACKGROUND:Current research has shown that many cellgrowth factors can promote the proliferation and differentiation of epiphysis stem cells, and this regulation is closely related to Sox-9. OBJECTIVE:To investigate the effects of smal interfering RNA-induced specific silence of Sox-9 gene on the proliferation and apoptosis of epiphysis stem cells. METHODS:Epiphysis stem cells were isolated from the ring of La Croix with enzyme digestion and purified with magnetic activated cellsorting, identified by immunocytochemistry assay. The cells in good conditions were selected to be transfected by Sox-9 silenced by smal interfering RNA with fluorescent marker, and then were observed under the fluorescent microscope to check the transfection efficiency. Next step, epiphysis stem cells were divided into 2 groups:group one was cultured normal y as control group;group two was transfected by Sox-9 silenced by smal interfering RNA through LipofectamineTM 2000 as experimental group. RESULTS AND CONCLUSION:The primary epiphysis stem cells were separated and purified, which were of stable growth and tightly attachment. The results of immunohistochemistry and immunofluorescence showed the epiphysis stem cells expressed cel-specific markers, fibroblast growth factor receptor 3. After transfection, reverse transcription-PCR results showed that Sox-9 gene expression in epiphysis stem cellwas inhibited specifical y;3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide results showed that cellproliferation in experimental group decreased significantly compared with the control group (P<0.05), and the cellapoptosis detected by flow cytometry showed that the experimental group increased as compared with the control group (P<0.05). Sox-9 gene plays an important role in regulating the proliferation and apoptosis of rat epiphysis stem cells.
ABSTRACT
Objective To evaluate the biomechanical characteristics of the long U-shaped hollow pedicle screw system for percutaneous fixation of thoracolumbar fractures.Methods Models of vertebral compression fracture were created by flexion in 8 fresh cadaveric samples of thoracolumbar spine.The models were divided into 2 equal groups according to the fixation system applied.In group A conventional pedicle screws were used while in group B long U-shaped hollow pedicle screws were used.The yield compressive strength,axial compression stiffness,bending stiffness,torque and torsional stiffness of all the fixated spines in the 2 groups were tested by the bio-mechanical electrical measurement and compared as well.Results The conventional pedicle screws and long U-shaped hollow pedicle screws showed no significant differences regarding yield compressive strength (3450.02 ± 110.03 MPa vs.3430.04 ± 102.12 MPa),axial compressionstiffness (407.52 ± 33.02 N/mm vs.395.04 ± 26.46 N/mm),bending stiffness (305.14 ± 26.53 N · cm/Degvs.295.12±23.80 N · cm/Deg),torque (6.45±0.25 N · m vs.6.25±0.21 N · m) or torsional stiffness (0.54±0.04N·cm/Degvs.0.52±0.03N·cm/Deg) (P＞ 0.05).Conclusion The long U-shaped hollow pedicle screw system can satisfy the biomechanical requirements for fixation of thoracolumbar fractures and can function as well as the conventional pedicle screw system.