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OBJECTIVE: To explore the protective effect of tea polyphenols and its mechanism in potassium dichromate(PD)-induced acute renal injury in mice. METHODS: The specific pathogen free weaned Kunming mice were divided into control group, model group and low-, middle-and high-dose tea polyphenols groups, with 12 mice in each group. Mice in the control group were given 0.9% sodium chloride solution, and mice in other four groups were given PD solution with 4.275 mg/kg body weight every morning by intragastric administration. Then, mice in the control group and model group were given 0.9% sodium chloride solution in the afternoon, while mice in the low-, middle-and high-dose tea polyphenols groups were given 0.3 mL tea polyphenols solution with a dose of 200, 400 or 600 mg/kg body weight, respectively by gavage, once a day for two consecutive weeks. The body mass of mice was weighed during the experiment. At the end of the experiment, the mice were sacrificed. The kidneys were removed and weighed. The kidney organ coefficients were calculated. The levels of urea nitrogen and creatinine in serum were determined by two-point method, the activities of catalase(CAT) and glutathione peroxidase(GSH-Px) in serum of mice were detected by colorimetry. The pathological change of kidney in mice was observed. RESULTS: The body weight of mice in the model group decreased(P<0.05), while the kidney mass, renal organ coefficient, serum levels of urea nitrogen and creatinine increased(all P<0.05), and the serum activities of CAT and GSH-Px decreased(all P<0.05) compared with the control group. The body weight of mice in the three tea polyphenols groups increased(all P<0.05), while the kidney mass, renal organ coefficient, urea nitrogen and creatinine levels in serum decreased(all P<0.05), and the activities of CAT and GSH-Px in serum increased with the increasing intervention dose of tea polyphenols(all P<0.05) compared with the model group. The change of acute renal injury was mainly caused by renal tubular injury in the model group. The pathological changes of renal tissue in the three tea polyphenols intervention groups were improved compared to that in the model group, and the improvement showed a dose-effect relationship with the intervention of tea polyphenols. CONCLUSION: Tea polyphenols have a protective effect on PD-induced acute renal injury with a dose-effect relationship. Its mechanism of action is related to the fact that tea polyphenols can reduce or reverse oxidative stress and inflammation in the kidney.
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Objective@#To investigate the stress corrosion and electrochemical corrosion resistance of titanium produced through laser rapid forming (LRF), and to provide a basis for their clinical application.@*Methods@#Forged commercial pure titanium (CP-Ti) was used as control group and LRF pure titanium was used as LRF group. All samples were placed in acidic artificial saliva containing fluorine (pH=7), and loaded with a stress of 1.2 × σ0.2 Pa (σ0.2 represents the yield strength of material). Stress corrosion resistance of specimens that have been soaked for 30 days was analyzed by naked eye observation, X-ray diffraction analysis and scanning electron microscopy. For samples placed in artificial saliva, neutral fluoride solution (pH=7) and acidic fluoride solution (pH=3) (4 test pieces in each corrosive medium), and their electrochemical corrosion resistance was evaluated by free corrosion potential (Ecorr) measurements, corrosion current (Icorr), electrochemical impedance spectroscopy (EIS), and anodic polarization curves.@*Results@#With the prolongation of immersion time, the corrosion products gradually increased. The stress corrosion of CP-Ti group was significantly more than that of LRF-Ti group, and the pit diameter was significantly larger than that of LRF-Ti group. The electrochemical corrosion results showed that the Ecorr (-469 mV) of LRF-Ti in artificial saliva was higher than that of CP-Ti (-555 mV), and the Ecorr (-925 mV) of LRF-Ti was higher than that of CP-Ti (-943 mV) in neutral fluoride solution. In acid fluoride solution, the Ecorr (-943 mV) of LRF-Ti was higher than that of CP-Ti (-956 mV). The Ecorr of the same metal was the highest in artificial saliva and the lowest in acid fluoride solution; the Icorr of the same metal was the lowest in artificial saliva and the highest in acid fluoride solution.@*Conclusions@#Under the same corrosion conditions, LRF Ti demonstrated better stress and electrochemical corrosion resistance than CP-Ti.
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Objective@#To evaluate the antiseptic effect of combined using of 5% sodium hypochlorite and calcium silicate-based root canal sealer against Enterococcus faecalis (Ef) biofilms in infected dentinal tubules in vitro.@*Methods@#Cells of Ef were inoculated into the dentinal tubules of single-rooted teeth (without caries, periapical lesions and malformations extracted due to periodontal disease or orthodontic reasons; collected from Department of Maxillofacial Surgery, The First Affiliated Hospital of Zhengzhou University) with centrifugation and incubated in brain-heart infusion (BHI) to form 3-week-old biofilms. The infected samples were subjected to sodium hypochlorite or sterile water bathing for 10 minutes followed by calcium silicate-based root canal sealer (iRoot SP) (calcium silicate-based group), Gutta-percha group and sterile water group placed on the root canal wall for 1, 4 and 12 weeks. There were two samples in each treatment at each point. The antiseptic effectiveness of combined use of sodium hypochlorite and calcium silicate-based root canal sealer was analyzed by laser scanning confocal microscope (LSCM), ANOVA and LSD-t test.@*Results@#After treatment with 5% sodium hypochlorite, in calcium silicate-based group for 4 and 12 weeks more Ef biofilm cells [(75.3±3.5)% and (74.8±3.8)%] were killed than in Gutta-percha group [(65.9±4.1)% and (63.0±3.7)%] and sterile water group [(63.9±4.0)% and (64.2±3.5)%] (P<0.05). After being treated with sterile water, the proportion of dead bacterial cells in calcium silicate-based group for 1, 4 and 12 weeks [(27.5±4.6)%, (43.0±4.4)% and (40.3±6.1)%] were more than those in Gutta-percha group and sterile water group (P<0.05). After being treated with 5% sodium hypochlorite or sterile water, more biofilm bacteria were killed in calcium silicate-based group for 4 and 12 weeks than in calcium silicate-based group for 1 week (P<0.05).@*Conclusions@#The combined use of sodium hypochlorite and calcium silicate-based root canal sealer kills more biofilm cells in infected dentinal tubules.
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OBJECTIVE@#The purpose of the study was to analyze the characteristics of elder patients with maxillofacial fracture.@*METHODS@#We retrospectively analyzed the characteristics of maxillofacial fractures in the elder patients, who were treated from July 2010 to October 2017. The clinical characteristics of the etiology, fracture site, combined injury, systemic disease, and treatment method were analyzed.@*RESULTS@#In the 198 elderly patients with maxillofacial fractures, the male-to-female ratio was 3.95︰1, and the mean age was 66.15 years old. Traffic accident injury (78 patients, 39.39%), fall injury (49 patients, 24.75%), high fall injury (33 patients, 16.67%) were the main factors of maxillofacial fracture in elderly patients. The most frequently observed fracture site was the mandible (120 patients). A total of 60 patients demonstrated associated injuries, in which limb injuries were the most prevalent (28 patients); whereas 66 patients had other systemic medical conditions, in which cardiovascular diseases was the most frequent (50 patients). The main treatment method of 198 patients was rigid internal fixation with small or micro-plates.@*CONCLUSIONS@#Falling and traffic accidents are the main factors of maxillofacial fracture in elderly patients. Thus, interference measures should be observed for the prevention of maxillofacial fractures in elderly patients.
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Aged , Female , Humans , Male , Accidental Falls , Accidents, Traffic , Fracture Fixation, Internal , Maxillofacial Injuries , Retrospective StudiesABSTRACT
Objective@#To evaluate the antimicrobial activity of nonequilibrium plasma against Enterococcus faecalis (Ef) biofilms in vitro and to obtain novel evidence of root canal disinfection with nonequilibrium plasma.@*Methods@#Sterile cover slips and single-rooted canals were filled with Ef and incubated to form 1-week-old and 3-week-old biofilms, respectively. The infected samples were subjected to nonequilibrium plasma, 2% chlorhexidine digluconate (CHX) and saline for 3, 10 and 30 minutes, respectively. After treatment, the killing effectiveness of nonequilibrium plasma was analyzed by using laser scanning confocal microscopy (LSCM) and colony forming unit (CFU) counting.@*Results@#The 3-dimentional reconstruction LSCM images showed that about 48.3%-79.8% of 1-week-old Ef biofilm cells and 40.0%-67.4% of 3-week-old biofilm cells were killed by nonequilibrium plasma and 2% CHX compared to saline (P<0.05). The proportion of killing activity was lower after 3 minutes (40.0%-50.9% killing) than after 10 minutes (65.3%-77.8% killing) and 30 minutes (66.4%-79.8% killing) (P<0.05). And the killing of biofilm bacteria was fastest during the first 3 minutes (13.3%-17.0% killing per minute) and slow down greatly after 10 minutes. Remarkably more bacteria were killed in 1-week-old Ef biofilms (48.3%-79.8% killing) than in 3-week-old biofilms (P<0.05).@*Conclusions@#The nonequilibrium plasma killed more Ef biofilm cells in infected root canals showed promotional as an additional approach against bacterial biofilms during root canal disinfection.