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To investigate the characteristics of low activity ChiC from A. veronii B565 and break the bottleneck of its application, this experiment established a recombined ChiC pichia engineering bacteria GS115/PIC9-ChiC, carried out methanol induction expression and purification, and studied its basic enzymology properties. The result indicated that ChiC was expressed in P. pastoris with a yield of 232.6 mg/L after 48 h methanol induction. The purified ChiC showed optimal specific activity of 7.6 U/mg at pH 8.0 and 40°C. ChiC had broad adaptability for pH and temperature. It retained over 80% optimal activity at pH 3.0~10.0 at 40°C or the temperature 0~40°C at pH 7.0. The chitin binding protein CBP21 from Serratia marcescens GIM1.217 was expressed in E. Coli. The affinity of CBP21 for shrimp shell chitin and colloidal chitin were different, the chitinase activity of ChiC was increased significantly from 2 (colloidal chitin as substrate) to 9 (shrimp shell chitin as substrate) fold, when acted synergistically with CBP21. This study laid a theoretical foundation for further slurrying chitinase gene, and provided a possible solution for breaking the bottleneck of this low enzyme activity of chitinase application. [ABSTRACT FROM AUTHOR]

Purpose: To explore the mechanism of SETDB1 inhibiting epithelial mesenchymal transition (EMT),migration and invasion in oral cancer via SOX 7 methylation., Methods: SETDB1 and SOX7 mRNA and protein expression levels in KB cells of oral cancer and oral mucosal epithelial ATCC cells were determined by qRT-PCR and Western blot (WB). SETDB1 si-RNA was structured, then transfect into KB cells of oral cancer by liposome-mediated method. siRNA-SETDB1 was the experimental group (si-S), siRNA empty vector was the negative control group (si-N), and untransfected KB cells were the blank control group(NC). SETDB1 mRNA and protein expression levels were detected by qRT-PCR and Western blot(WB), to verify the transfection effect. The methylation levels of SOX7 were determined by pyrosequencing. The expression of N-cadherin, Vimentin, β-catenin, and Slug proteins was detected by WB. Cell viability was measured by MTT assay, migration ability was tested by scratch healing assay, and invasion ability was tested by Transwell chamber assay. Statistical analysis was performed with SPSS 21.0 software package., Results: The results of Rt-qPCR and WB showed that the SETDB1 mRNA and protein expression decreased significantly in si-S group(P＜0.05). Pyrosequencing test results showed that the regulation of SETDB1 could significantly reduce the SOX7 methylation rate and increased the SOX7 protein expression. WB results showed that knockdown of SETDB1 significantly inhibited the expression of EMT-related proteins N-cadherin, Vimentin, β-catenin and Slug in oral cancer KB cells (P＜0.05). The results of cell functology experiments showed that knockdown of SETDB1 could significantly inhibit survival, migration and invasion of KB cells., Conclusions: Downregulation of SETDB1 could suppress EMT, migration and invasion of oral cancer cells by regulating SOX7 methylation level, providing new ideas and targets for the diagnosis and treatment of oral cancer.

Objective: To prepare Pluronic F-127 composite gel loaded with transforming growth factor β 3 (TGF-β 3 ) and bone marrow mesenchymal stem cells (BMSCs) and observe its osteogenesis and angiogenesis effects in vivo and in vitro ., Methods: BMSCs were isolated from the tibial and femoral bone marrow of New Zealand white rabbits and passaged, and the 3rd generation cells were used for subsequent experiments after identification of osteogenic and adipogenic induction. Pluronic F-127 powder and TGF-β 3 were dissolved in L-DMEM medium to prepare Pluronic F-127 gel, TGF-β 3 +Pluronic F-127 gel, BMSCs+Pluronic F-127 gel, and TGF-β 3 +BMSCs+Pluronic F-127 gel. The 3rd generation of BMSCs were cultured with L-DMEM medium (group A), osteogenic induction medium (group B), osteogenic induction medium containing Pluronic F-127 gel (group C), and osteogenic induction medium containing TGF-β 3 +Pluronic F-127 gel (group D), respectively. After 14 days of culturing, alkaline phosphatase (ALP) staining and Alizarin red staining were used to observe the osteogenesis. In addition, the BMSCs were cultured with L-DMEM medium containing Pluronic F-127 gel (experimental group) and L-DMEM medium (control group) for 1, 2, 3, and 4 days, respectively. And the cell proliferation was detected by MTT assay. Ten New Zealand white rabbits were taken to prepare the maxillary sinus lift models, and Pluronic F-127 gel (group A), TGF-β 3 +Pluronic F-127 gel (group B), BMSCs+Pluronic F-127 gel (group C), and TGF-β 3 +BMSCs+Pluronic F-127 gel (group D) were injected into the bone defects, respectively. On the 8th week, imaging examination and HE staining were used to observe the formation of new bone, immunohistochemical staining was used to observe the expression of vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2) in bone tissue, and Western blot was used to detect the relative expressions of VEGF, oncostatin M (OSM), and BMP-4 proteins in bone tissue., Results: Osteogenic and adipogenic induction identified the isolated and cultured cells as BMSCs. In vitro staining showed that ALP activity and Alizarin red concentration in group D were significantly higher than those in other groups ( P <0.05). MTT assay showed that the absorbency ( A ) value of the two groups increased gradually, and there was no significant difference between the groups at each time point ( P >0.05). In vivo experimental imaging examination showed that the bone mineral density and osteogenic continuity of group D were the best, and the proportion of new bone volume was superior to other groups ( P <0.05). HE staining showed that compared with other groups, bone trabeculae in group D were dense and arranged regularly, on which a large number of osteoblasts and osteoclasts were distributed, and a large number of new bone formation could be seen. Immunohistochemical staining showed the strong positive expressions of BMP-2 and VEGF in group D ( P <0.05); Western blot detection showed that the relative expressions of VEGF, OSM, and BMP-4 proteins in group D were significantly higher than those in other groups ( P <0.05)., Conclusion: The BMSCs in Pluronic F-127 composite gel loaded with TGF-β 3 and BMSCs can be induced to differentiate into osteoblasts, and the composite gel has no toxic effect on cells, and has obvious osteogenesis and angiogenesis in the maxillary sinus of rabbits.

Objective: To investigate the causes and clinical features of children with traumatic brain injury (TBI) who need hospitalization or emergency observation., Methods: A retrospective analysis was performed for the clinical data of 126 children with TBI who were admitted to the emergency department from January 1, 2014 to August 31, 2016, including causes of injury and clinical features., Results: Of the 126 children, there were 95 boys and 31 girls, with a mean age of 2.8 years (range 0.8-5.5 years). The children aged <1 year accounted for 38.1% (48/126), and 26 children died. The two most common types of TBI were epidural hematoma (54.0%) and subarachnoid hemorrhage (50.8%). Of the 126 children, 83 (65.9%) had a Glasgow Coma Scale score of ≤8 within 24 hours after admission. There were different causes of TBI and places where TBI occurred in different age groups. The two leading causes of TBI were falls (51.6%) and road traffic injuries (42.9%). Compared with those in the other age groups, the children in the age <1 year group were most likely to experience injury due to falls (46%; P=0.023). Thirty-five percent of all TBI due to road traffic injuries occurred in the children aged 3-6 years (P<0.001). Most TBI cases occurred at home (47.6%) or on roads/streets (45.2%). Among those who experienced TBI at home, the children aged <1 year accounted for the highest proportion of 48% (P=0.002), and 53% of the patients aged 3-6 years experienced TBI on roads/streets. The most common cause of death in children with TBI was road traffic injury, which accounted for 69%. Among those who died, the children aged <1 year accounted for the highest proportion (62%)., Conclusions: There are different causes of TBI and places where TBI occurs in different age groups. Among children with TBI, the children aged <1 year account for the highest proportion and have the highest number of deaths, with falls at home as the most common cause of TBI. Children aged 3-6 years tend to suffer TBI due to road traffic injury. Road traffic injury is the leading cause of death.

Objective: To investigate the changes in expression level of human leucocyte antigen-DR (HLA-DR) on CD14(+) monocyte (CD14(+)/HLA-DR) in the patients after orthotopic liver transplantation, and its role in monitoring postoperative infection., Methods: Sixty-three patients with liver transplantation were divided into three groups, non-infection group with 47 cases, infection group with 10 cases and septic shock group with 6 cases [according to the definition of septic shock of American College of Chest Physicians/Society for Critical Care Medicine (ACCP/SCCM)]. CD14(+)/HLA-DR expression ratio was assessed with flow cytometer, and its clinical implication was evaluated by receiver operating characteristic (ROC) curve assay., Results: CD14(+)/HLA-DR expression ratio in infection group [(29.6+/-7.2)%] and septic shock group [(16.3+/-10.5)%] were significantly lower than that in non-infection group [(62.3+/-18.3)%, both P<0.01], but no significant difference of CD14(+)/HLA-DR expression ratio was found between infection group and septic shock group (P=0.128). Total area under ROC curve of CD14(+)/HLA-DR expression ratio for the infection was 0.965, its sensitivity and specificity at 36.35% cut off were 100.0% and 93.6%, respectively. Total area under ROC curve of CD14(+)/HLA-DR expression ratio to predict septic shock was 0.968, its sensitivity and specificity at 31.97% cut off were 100.0% and 87.7%, respectively. Comparing the change of CD14(+)/HLA-DR expression, it was lower in the infection group and septic shock group (P<0.05 and P<0.01), and the expression rate was lowest during period of serious infection in the two groups [infection group: (29.6+/-7.2)%, septic shock group: (16.3+/-0.5)%, all P<0.01]., Conclusion: For the patients with possible infection after liver transplantation, sequential assessment of CD14(+)/HLA-DR expression ratio would be a good marker for the judgment of patient's conditions and outcome. CD14(+)/HLA-DR expression ratio below 36.35% could be used as the prewarning value for the diagnosis of postoperative infection, and 31.97% could be used as the critical value for the diagnosis of septic shock.

Objective: To summarize the reasons for bile duct injury (BDI) after laparoscopic cholecystectomy (LC), and to determine the effect of multiple treatment after BDI., Methods: A retrospective cohort study was performed. The medical records of 110 patients diagnosed with BDI after LC from October 1993 to November 2007, in ten large hospitals in Guangdong of China, were reviewed., Results: Among 110 patients with BDI, 58 cases (52.7%) were local patients, whereas 52 cases (47.3%) were transferred from outside hospitals. Reasons for BDI following LC were: (1) Lack of experience of the LC operator (48.2%); (2) LC performed during acute cholecystitis (20.0%); (3) The structure of Calot triangle was unclear (15.5%); (4) Variable anatomical position (11.8%); (5) Intra-operation bleeding (4.5%). The commonest sites of injury were the choledochus and common hepatic duct (76.4%). Following BDI, endoscopic stenting or operative repair was performed in 106 patients. The overall success rate was 95.3% (101/106), with a mortality rate was 0.9% (1/106). Cholangitis occurred in 3.8% (4/106) cases. Choledocho-enterostomy operation was performed in almost 60.0% (63/106) cases, and the success rate was 93.7% (59/63). Endoscopic stenting or operative repair was performed immediately following BDI in 23.6% (25/106) patients, the success rate was 100%; and within 30 days in 63.2% (67/106) patients. Eighty-eight out of 106 patients who underwent repair were successful following the first operative procedure., Conclusions: Factors such as an un-experienced operator and unclear anatomical position were causes of BDI following LC. Early operative repair should be regarded as the treatment of choice, in patients diagnosed with BDI. Early refer to an experienced hepatobiliary operator ensures a high success rate.

Objective: To assess the value of the model for end-stage liver disease (MELD) in predicting the early-stage outcome of liver transplantation in patients with end-stage liver disease., Methods: The MELD scores of 87 liver transplantation recipients with end-stage liver disease were calculated, and their early-stage complications and mortality were analyzed., Results: The incidence of severe complications was 20.7%; in these recipients, with the 28-day and 3-month survival rates of 89.7%; and 88.5%;, respectively. The mean MELD scores showed significant differences between the complication-free group and survival group (14.6 vs 12.9, P<0.05), and also between the complication group and death group (21.6 vs 29.4, P<0.05). Compared to patients with MELD no greater than 15, patients with MELD between 16 and 24 showed significantly increased complication rate but had comparable survival rate (P>0.05); but in patients with MELD no less than 25, the survival rate was significantly decreased with also increased complication rate., Conclusions: A higher MELD score before liver transplantation is associated with greater likeliness of early-stage complication rate and mortality. High MELD score (over 25) can be a useful index in predicting severe complications and death in patients undergoing liver transplantation.