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BACKGROUND:In the treatment of skin trauma with active repair,tissue engineering techniques are needed to generate new tissue to replace necrotic tissue.Skin scaffolds have a good application prospect in the field of wound repair.Skin scaffolds need to present three-dimensional porous structures with certain mechanical strength to meet the needs of cell proliferation and division.However,the mechanical strength of the currently used gelatin-based biomaterials is weak and cannot meet the requirements of the use of skin scaffolds. OBJECTIVE:To study the 3D printing process used in the preparation of tissue engineering skin scaffolds by gelatin/oxidized nanocellulose composites,and focus on the relationship between the porosity and mechanical strength of the scaffolds prepared under different process parameters. METHODS:Oxidized nanocellulose whiskers at 10%concentration were extracted from Humulus scandens and then compounded with 5%gelatin to obtain gelatin/oxidized nanocellulose composites.The elastic modulus of gelatin and gelatin/oxidized nanocellulose composite was determined.Skin scaffolds were prepared by 3D printing extrusion molding using gelatin/oxidized nanocellulose composite as the base material.Mechanical and rheological properties of the composite were tested to determine extrusion molding parameters(filling gap 1.5-2.5 mm,uniform distribution of 0.1 mm;air pressure of 160-200 kPa),and the skin scaffold with a three-dimensional porous structure was prepared.The compressive performance of the skin scaffold was tested and compared with the finite element analysis results.The relationship between the filling gap and the porosity and mechanical strength of the scaffold was demonstrated. RESULTS AND CONCLUSION:(1)The elastic modulus of 5%gelatin was increased by 8.84 times by adding 10%oxidized nanocellulose whisker.A gel filament with a diameter of 1 mm was obtained by extrusion at the air pressure of 160 kPa.When the filling gap increased from 1.5 mm to 2.5 mm,the theoretical porosity of the scaffold increased from 33%to 60%,but the compressive strength decreased from 230 000 Pa to 95 000 Pa.(2)These findings showed that the skin scaffold with theoretical porosity of 50%and elastic modulus of 160 000 Pa was prepared by using 2 mm filling gap.The scaffold had a clear three-dimensional porous structure.
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Objective To identify the activity of HCV IRES translation differences and identify the relationship between HCV IRES translation activity and ROS in different concentrations of ferric ammonium citrate ( FAC) in-duction.Methods 1 ) Expression plasmid pCI-Rluc-HCV IRES-Fluc was confirmed by endonuclease digestion as well as luciferase transient expression in Huh-7 cell;2) Controlled by dual-luciferase reporter assay, the differ-ent translation activity of HCV internal ribosomal entry site ( IRES ) was examined in a concentration of 50 μmol/L and 300μmol/L of FAC induction;ROS fluorescent staining method was used to detect the activity of ROS in Huh-7 cells, Western blot method was used to detect the protein expression changes of Nrf2 in Huh-7 cells;3) On the basis of the above experiments, 100 μmol/L DPI was added in 300 μmol/L FAC experimental group, to analyse the changes of HCV replication and ROS production after joining DPI.Results The generation of ROS and the activity of luciferase in the model group were significantly higher than that in the control group ( P<0.05 ) .FAC can enhance the expression of HCV IRES and increase the production of ROS , then causing Nrf2 expression in Huh-7 cell.However,after adding ROS inhibitor DPI, the above functions in Huh-7 cell were weakened.Conclusions The increase of HCV IRES expression induced by FAC is related to excessive ROS pro-duction induced by FAC in Huh-7 cells.
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Objective@#To explore the effects of hypertonic sodium saline (HSS) resuscitation on the liver damage of rats at early stage of severe scald.@*Methods@#Fifty-six SD rats were divided into sham injury group (SI, n=8), lactated Ringer′s solution group (LRS, n=24), and group HSS (n=24) according to the random number table. Rats in group SI were sham injured without resuscitation, while rats in the other two groups were reproduced deep partial-thickness to full-thickness scald model with 30% total body surface area on the back. Rats in group LRS were resuscitated with LRS, while rats in group HSS were resuscitated with 300 mmol/L sodium ion solution according to the Parkland formula. Blood of abdominal aorta and liver of 8 rats in group SI immediately post injury and in the other two groups at post injury hour (PIH) 2, 8, and 24 respectively were collected. Then liver water content was determined by dry-wet weight method. Serum content of alanine aminotransferase (ALT) and aspartate transaminase (AST) was detected by automatic biochemical analyzer. Serum content of tumor necrosis factor α (TNF-α), interleukin-1 (IL-1), and high mobility group box 1 (HMGB1) was determined by enzyme-linked immunosorbent assay. Liver content of malondialdehyde (MDA) and superoxide dismutase (SOD) was detected by ultraviolet spectrophotometer. Pathologic changes of liver were observed by HE staining. Data were processed with one-way analysis of variance and SNK test.@*Results@#(1) At PIH 2, 8, and 24, liver water content of rats in group LRS was higher than that in group SI and group HSS (P<0.05 or P<0.01). (2) At PIH 2, serum ALT content of rats in the three groups was similar (with P values above 0.05). At PIH 8 and 24, serum ALT content of rats in group HSS and group LRS was higher than that in group SI (P<0.05 or P<0.01), and serum ALT content of rats in group HSS was lower than that in group LRS (with P values below 0.01). At PIH 2, 8, and 24, serum AST content of rats in group HSS and group LRS was higher than that in group SI (with P values below 0.01). At PIH 2 and 8, serum AST content of rats in group HSS was lower than that in group LRS (P<0.05 or P<0.01). (3) At PIH 2 and 8, serum TNF-α content of rats in group LRS was (123±39) and (153±38) pg/mL respectively, higher than that in group SI [(60±18) pg/mL] and group HSS [(85±10) and (94±16) pg/mL respectively, with P values below 0.01]. At PIH 8, serum TNF-α content of rats in group HSS was higher than that in group SI (P<0.05). At PIH 24, serum TNF-α content of rats in the three groups was similar (with P values above 0.05). At PIH 2, 8, and 24, serum IL-1 content of rats in group LRS was (122±35), (141±30), and (122±31) pg/mL respectively, and that in group HSS was (80±12), (93±15), and (80±11) pg/mL respectively, all higher than that in group SI [(40±17) pg/mL, with P values below 0.01]; serum IL-1 content of rats in group HSS was lower than that in group LRS (with P values below 0.01). At PIH 2, serum HMGB1 content of rats in the three groups was similar (with P values above 0.05). At PIH 8 and 24, serum HMGB1 content of rats in group LRS was (0.386±0.146) and (0.590±0.188) ng/mL respectively, higher than that in group SI [(0.050±0.027) ng/mL] and group HSS [(0.143±0.038) and (0.309±0.095) ng/mL respectively, with P values below 0.01]. At PIH 24, serum HMGB1 content of rats in group HSS was higher than that in group SI (P<0.01). (4) At PIH 2, 8, and 24, liver MDA content of rats in group HSS and group LRS was higher than that in group SI and their liver SOD content was lower than that in group SI (with P values below 0.01); liver MDA content of rats in group HSS was lower than that in group LRS and their liver SOD content was higher than that in group LRS (with P values below 0.01). (5) Compared with those of rats in group SI, liver cells of rats in group LRS showed massive steatosis at each time point, and liver cell-edema appeared at PIH 8 and 24; while liver cells of rats in group HSS showed little steatosis only at PIH 8 and 24, and the liver cell-edema never appeared.@*Conclusions@#Compared with LRS, HSS resuscitation can alleviate liver injury of rats at the early stage of severe scald through relieving inflammatory mediators and reducing degree of oxidative stress, etc.
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Objective To investigate the effects of three different concentrations of hypertonic sodium salt (HS) resuscitation on liver injury of rats at the early stage of severe burned.Methods 104 female Sprage-Dawley (SD) rats were randomly divided into five groups: sham group (n = 8), lactated Ringer solution (LR) group (n = 24), 600, 800, 1000 mmol/L HS groups (HS600, HS800, and HS1000 groups,n = 24). Rats in LR group and HS groups were subjected to full-thickness scald with 30% total body surface area (TBSA), and then given liquid resuscitation treatment with LR and the corresponding HS. These rats were sacrificed at 2, 8 and 24 hours post injury to collect blood and liver tissue. Rats in sham group were given simulation of burns without resuscitation, which were immediately sacrificed and the specimens were harvested. The levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected by automatic biochemical analyzer. The levels of liver tissue malondialdehyde (MDA) and superoxide dismutase (SOD) were detected by ultraviolet spectrophotometry. The expression of liver tissue p38 mitogen-actirated protein kinase (p38MARK) was detected by Western Blot.Results Compared with sham group, the levels of ALT, AST, MDA and p38MAPK were increased, and the activities of SOD were decreased in LR group and different degrees in HS groups at each time point after injury. Compared with LR group, the levels of ALT, AST, MDA and p38MAPK were decreased and the activities of SOD were increased in different degrees with HS groups, among which HS600 group changed most significantly [ALT (U/L): 147±52 vs. 227±60 at 8 hours, 138±47 vs. 191±41 at 24 hours; AST (U/L):288±79 vs. 548±237 at 2 hours, 567±167 vs. 841±338 at 8 hours, 515±180 vs. 712±159 at 24 hours; MDA (nmol/mg): 0.287±0.036 vs. 0.395±0.041 at 2 hours, 0.298±0.030 vs. 0.392±0.018 at 8 hours, 0.278±0.033 vs. 0.422±0.036 at 24 hours; SOD (U/mg): 230±16 vs. 159±30 at 2 hours, 251±14 vs. 194±15 at 8 hours, 296±8 vs. 243±11 at 24 hours; p-p38MAPK/p38MAPK (A value): 0.778±0.040 vs. 1.065±0.066 at 2 hours, 0.791±0.046 vs. 0.967±0.041 at 8 hours, 0.733±0.027 vs. 1.020±0.043 at 24 hours; allP < 0.05]. The levels of ALT and AST in HS600 group were significantly lower than those in HS1000 group at 2 hours and in HS800 group at 8 hours. The levels of MDA and p38MAPK in HS600 group were significantly lower than those of HS800 group and HS1000 group, and the level of SOD in HS600 group was significantly higher than that in HS800 group and HS1000 group at each time point after injury. There were no significant differences in all test indicators between HS800 group and HS1000 group at each time point after injury.Conclusions High concentration of HS can reduce the early liver injury in severely scalded rats, of which the curative effect of HS 600 mmol/L is best.
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OBJECTIVE: To investigate the effects of arc-track private lock pedicle orthopedic fixation system Ⅱ (ALPF Ⅱ) on treatment of spinal diseases. METHODS: A total of 86 patients with spinal diseases were treated using self-made ALPF in the Wendeng Orthopaedic Hospital and were included in this study. Of these patients, 14 suffered from cervical spinal stenosis complicated by cervical vertebral destabilization, 29 from thoracolumbar fractures and dislocations, 15 from lumbar spinal stenosis complicated by lumbar vertebral destabilization, 2 from lumbar spondylolisthesis, 8 from spinal tuberculosis, 6 from ankylosing spondylitis, 9 from idiopathic scoliosis, and 3 from congenital scoliosis. According to conditions, different therapeutic regimens were selected. Postoperatively, regular follow-up was performed to observe vertebral healing, intervertebral height, spinal column sequence, and neurological function recovery. RESULTS: All patients were followed up for 9-30 months (average 12 months). The improvement rate of neurological function, spinal mobility, back pain, and melosalgia was 94.1%, 65.9%, 92.1%, and 87.4%, respectively. The postoperative anterior and posterior vertebral heights were apparently recovered, and kyphotic angle was well corrected. No screw, rod loosening or breakage was found. CONCLUSION: Self-made ALPF Ⅱ is an internal fixation method for treatment of spinal diseases. It provides good reduction, reliable curative effects, less complications, and no biocompatibilities.
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OBJECTIVE:To study the tumor targeting of RGD-PEG-liposomes METHODS:RGD-PEG-liposome was prepared by reverse phase evaporation method and combination with GRGDS peptide Tumor targeting was studied in Colon 26 tumor bearing mice RESULTS:RGD-PEG-liposomes showed good tumor targeting effect on colon 26 tumor bearing mice CONCLUSION:RGD containing polypeptide conjugated,long-cyclic lipsome may become a new-type,receptor-mediated targeting agent
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OBJECTIVE:To discuss the significance of pharmacoeconomics applying in essential medicine system(EMS) and the duty of licensed pharmacist. METHODS:The relationship between theory of pharmacoeconomics and EMS was analyzed. Moreover,the theory of pharmacoeconomics served as technique to apply in EMS. RESULTS&CONCLUSION:Pharmacoeconomics is the theoretical basis of establishment of EMS so that it is important significance to guide the choice of essential medicines,establishment and improvement the production,supplication and using system of essential medicines. Medical staff should carry out the monitory and evaluation of national essential medicine system(NEMS) in practice and implement NEMS consciously.