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BACKGROUND:Most of the silver coating materials prepared using active screen plasma technology in the past do not involve the nanotechnology field.The formed silver coating is in a"thin film"form,which is coated on the surface of the substrate,and the distribution of silver particles on the surface is uneven.Its long-term antibacterial ability is challenged. OBJECTIVE:To prepare nano silver coatings capable of being"buried"within stainless steel(SS)substrates using active screen plasma surface modification(ASPSM)and to observe antibacterial activity. METHODS:The nano-silver coating was prepared by ASPSM technique on stainless steel substrate.Three groups of coating samples were prepared by adjusting the bombardment time(1,2,and 4 hours),which were denoted as 1 h-Ag-ASPSM@SS,2 h-Ag-ASPSM@SS and 4 h-Ag-ASPSM@SS,respectively.The antibacterial activity of the coatings was analyzed by antibacterial ring test and Gram staining.The antibiotic coating samples of gentamicin combined with vancomycin were prepared by using stainless steel as substrate and were recorded as ACNs.Stainless steel,2 h-Ag-ASPSM@SS,and ACNs were inserted into Staphylococcus aureus or Pseudomonas aeruginosa suspension,respectively.The long-acting(84 days)antibacterial activity of the samples was analyzed by coating plate method.Bone marrow mesenchymal stem cells were co-cultured with stainless steel,2 h-Ag-ASPSM@SS,and ACNs,respectively.CCK-8 assay,dead/alive staining,and lactate dehydrogenase activity of cell supernatant were detected.Stainless steel,2 h-Ag-ASPSM@SS,and ACNs were taken after continuous exposure to Staphylococcus aureus suspension for 12 weeks.The amount of residual viable bacteria on the surface of the material was evaluated by spread plate method.Vancomycin drug sensitive disk method was used to evaluate the resistance of residual live bacteria on the surface of materials. RESULTS AND CONCLUSION:(1)With increasing bombardment time,the diameter of nano silver on the sample surface and the silver content in the coating gradually increased.Among them,the 2 h-Ag-ASPSM@SS exhibited the highest surface silver content while forming uniformly spherical nanoparticles.(2)Antibacterial ring test and Gram staining results demonstrated that compared with 1 h-Ag-ASPSM@SS and 4 h-Ag-ASPSM@SS,the 2 h-Ag-ASPSM@SS exhibited better inhibitory effect on Staphylococcus aureus and pseudomonas aeruginosa.After co-culturing with bacteria for 42 and 84 days,the number of viable bacteria on the spread plate method was significantly lower in the 2 h-Ag-ASPSM@SS group compared to the stainless steel and ACNs groups.After co-culturing with Staphylococcus aureus for 84 days and Pseudomonas aeruginosa for 42 days,the number of viable bacteria on the surface of the eluate from the ACNs group was higher than that of the stainless steel group.(3)CCK-8 assay,live/dead staining and lactate dehydrogenase activity of cell supernatant displayed that 2 h-Ag-ASPSM@SS did not have obvious cytotoxicity.ACNs showed obvious cytotoxicity.(4)After co-culture with Staphylococcus aureus for 12 weeks,the residual viable bacteria on the surface of 2 h-Ag-ASPSM@SS group was less than that of stainless steel group,and the residual viable bacteria on the surface of the ACNs group was more than that of stainless steel group.Compared with the stainless steel group,the sensitivity to vancomycin was significantly decreased in the ACNs group(P<0.001),and there was no significant change in sensitivity to vancomycin in 2 h-Ag-ASPSM@SS group(P>0.05).(5)The above results indicate that the silver nanoparticle coated stainless steel greatly improves the deposition efficiency of silver nanoparticles on the stainless steel surface and has long-lasting antibacterial properties and good cell compatibility.
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Objective To isolate, culture and expand SD rat synovial mesenchymal stem cells in vitro and identify their potential multilineage differentiation. Methods Traumatic osteoarthritis models were made in SD rats. Synovial tissue was collected under aseptic conditions. The synovial tissue was digested with type I collagenase to isolate synovial mesenchymal stem cells. Cells were purified by limiting dilution of the monoclonal culture and expanded in vitro. After the third passage of culture, growth curve determination, adipogenesis induction, osteoinduction and chondrogenesis induction were performed. Real-time qPCR and Western blot were used to detect the expression of proteoglycan and type Ⅱ collagen after chondrogenic differentiation. Results In the present study, rat synovial mesenchymal stem cells exhibited a homogeneous, fibroblast-like, spindle-shaped morphology after passage in vitro. Synovial mesenchymal stem cells were subjected to adipogenesis induction, osteoinduction and chondrogenesis induction and being identified. Under the influence of inflammatory factors, mRNA of type Ⅱ collagen and proteoglycans was positively expressed in differentiated cells induced by chondrocytes using real-time qPCR and Western blot. Conclusion Rat-derived synovial mesenchymal stem cells still have good chondrogenic potential in inflammatory environment.
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Objective To evaluate the efficacy of ultrasound-guided quadratus lumborum block for analgesia after laparoscopic cholecystectomy. Methods Sixty American Society of Anesthesiologists physi-cal statusⅠorⅡ patients, aged 18-64 yr, with body mass index of 20-27 kg∕m2 , scheduled for elective laparoscopic cholecystectomy, were divided into 2 groups ( n=30 each) using a random number table meth-od: ultrasound-guided transversus abdominis plane block group ( group T) and ultrasound-guided quadratus lumborum block group (group Q). In T and Q groups, bilateral ultrasound-guided transversus abdominis plane block and quadratus lumborum block were performed after general anesthesia induction, respectively, with 0. 25% ropivacaine 20 ml for each side. All the patients received patient-controlled intravenous analge-sia with morphine after surgery, and visual analoge scale scores were maintained≤3 in the two groups. The cumulative consumption of morphine was recorded at 2, 4, 6, 12, 24 and 48 h after surgery. The occur-rence of adverse reactions such as nausea, vomiting, pruritus, over-sedation and respiratory depression was observed and recorded in the analgesic period. The operation time for nerve blocks and nerve blocks-related complications such as bleeding, accidental puncture into the abdominal cavity or intestinal injuries were re-corded. Results Compared with group T, the cumulative consumption of morphine was significantly de-creased at 6, 12, 24 and 48 h after surgery in group Q ( P<0. 05) . There was no significant difference in the operation time for nerve blocks between the two groups ( P>0. 05 ) . There were no adverse reactions such as nausea, vomiting, pruritus, over-sedation and respiratory depression or nerve blocks-related compli-cations in the two groups. Conclusion Ultrasound-guided quadratus lumborum block provides better effica-cy than transversus abdominis plane block when used for analgesia after laparoscopic cholecystectomy.
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BACKGROUND:Mechanical, inflammatory, and biochemical factors, particularly matrix metaloproteinases and reactive oxygen lead to chondrocyte degeneration in osteoarthritis. Curcumin has been shown to be a potent antioxidant; however, its protective effects against chondrocyte degeneration in osteoarthritis remain unclear. OBJECTIVE:To investigate the potential molecular mechanisms underlying the protective effects of curcumin on articular cartilage of osteoarthritis in rats. METHODS:A total of 30 Sprague-Dawley rats were used and randomly divided into model group (positive control,n=15) and normal group (negative control,n=15). Rat models of traumatic osteoarthritis were established, and then cartilage cels were isolated from articular cartilage and culturedin vitro. Chondrocytes were treated with curcumin (curcumin group) or PDTC (an inhibitor of nuclear factor-kappa B) for 24 hours. The expression level of nuclear factor-kappa B P65 in nucleus and cytoplasm in chondrocytes were determined by western blot assay and immunofluorescence. Moreover, mRNA expressions of type II colagen, matrix metaloproteinase-1 and -13 were analyzed using RT-qPCR. RESULTS AND CONCLUSION: Nuclear factor-kappa B P65 protein was mainly expressed in nucleus, but few in cytoplasm in positive control group; the reversed results were found in the curcumin group. Nuclear translocation of nuclear factor-kappa B P65 was observed mainly in nucleus in the positive control group; however, that was observed mainly in cytoplasm in the negative control, curcumin, and PDTC groups. Matrix metaloproteinase-1 and -13 mRNA expressions were significantly decreased, while type II colagen mRNA expression was significantly increased in the curcumin group compared with the positive control group. These findings indicated that curcumin protect chondrocytes against degeneration through inhibiting the activation of nuclear factor-kappa B signaling pathway, suppressing nuclear translocation of nuclear factor-kappa B P65 and inhibiting the expressions of matrix metaloproteinase-1 and -13, which are responsible for upregulation of type II colagen expression.
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Objective To evaluate the optimum ratio of medicine dosage for dexmedetomidine mixed with sufentanil used for patient?controlled intravenous analgesia ( PCIA) after Nuss procedure in pedi?atric patients with pectus excavatum. Methods Sixty pediatric patients diagnosed with pectus excavatum, aged 5-12 yr, weighing 18-50 kg, of ASA physical statusⅠorⅡ, scheduled for elective Nuss procedure under general anesthesia, were randomly divided into 3 equal groups using a random number table:different ratios of medicine dosage while dexmedetomidine was added to sufentanil groups ( SD1-3 groups) . Postopera?tive analgesia was as follows: group SD1 received sufentanil 1 μg∕kg + dexmedetomidine 2 μg∕kg; group SD2 received sufentanil 1 μg∕kg + dexmedetomidine 3 μg∕kg; group SD3 received sufentanil 1 μg∕kg +dexmedetomidine 4 μg∕kg. A mixture of tropisetron 0?1 mg∕kg and dexamethasone 0?1 mg∕kg ( in 100 ml of normal saline) was added in each group. The PCA pump was programmed to deliver 0?5 ml with a lockout interval of 15 min and background infusion at 2 ml∕h. The PCA pump was connected immediately after the end of operation, and sufentanil with a dosage of 0?1μg∕kg was used as a rescue analgesic within 48 h post?operatively. The VAS score was maintained below 4. The requirement for rescue analgesics was recorded. The Ramsay sedation scores was recorded at 4, 8, 12, 24 and 48 h postoperatively, and the occurrence of adverse reactions such as nausea and vomiting, bradycardia, over?sedation, respiratory depression, agitation and shivering was recorded within 48 h after surgery. Results No pediatric patients developed nausea and vomiting, respiratory depression, bradycardia, over?sedation, and shivering. No pediatric patients required rescue analgesics in SD2 and SD3 groups. Compared with group SD1 , the requirement for rescue analgesics and incidence of agitation were significantly decreased, and Ramsay sedation scores were increased at 4 and 8 h after operation in SD2 and SD3 groups. Ramsay sedation scores were significantly higher at 4 h after oper?ation in SD3 group than in SD2 group. Conclusion Dexmedetomidine 3 μg∕kg mixed with sufentanil 1μg∕kg is the optimum ratio of medicine dosage when used for PCIA after Nuss procedure in pediatric patients with pectus excavatum.