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A nitrite electrochemical sensor based on electrodeposition of zirconium dioxide nanoparticles on reduced graphene oxide modified electrode was successfully constructed for the detection of nitrite. The electrochemical behavior of the modified electrode was investigated by cyclic voltammetry and amperometric i-t curve. Under the optimal conditions, the amperometric i-t curve response of the electrode showed a linear relationship with nitrite concentration in the range of 3.0×10Symbolm_7-1.0×10Symbolm_6 mol/L and 1.0×10Symbolm_6-6.0×10Symbolm_6 mol/L, and the detection limit was 1.0×10Symbolm_7 mol/L (S/N=3). The fabricated sensor exhibited high sensitivity, good stability and high reproducibility. This sensor was applied for the detection of nitrite in sausage samples with favorable recoveries of 93.7％-110.4％ and relative standard deviation (RSD) of 1.6％-2.1％.
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Objective:To development a new method for sensitive detection of Porphyromanus gingivalis (P.gingivalis) based on magnetic encoding nanospheres and upconversion fluorescent encoding nanospheres.Methods:Magnetic and upconversion fluorescent encoding nanospheres were prepared by sol-gel method respectively,combined the monoclonal antibodies specific to P.gingivalis after modifying the surface of nanospheres.The system was used to detect P.gingivalis from mixed bacteria solution of P.gingivalis,F.nucleatum and S.mutans.Fluorescent microscopy with an external 980 nm near-infrared hght pulse laser,scanning and transmission microscope were used to evaluate the effectiveness of the detection system.Results:Magnetic and upconversion encoding nanospheres had better dispersion,particle size uniformity and homogeneous morphology.Besides,the magnetic encoding nanospheres had good magnetic properties and strong fluorescence intensity.P.gingivalis was captured by magnetic and upconversion encoding nanospheres in a mixed solution of the 3 bacteria with a detection limit of 10 CFU/ml.Conclusion:The method designed in this study can capture P.gingivalis sensitively in a mixed bacteria liquid.
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Objective Recombinant human parathyroid hormone(1-34) [ rhPTH(1-34)] is the unique anabolic substance acting on the skeleton. The efficacy and safety of long-term administration of rhPTH(1-34) in Chinese postmenopausal women have not been evaluated. This study compared the clinical efficacy and safety of rhPTH(1-34) with elcatonin for treating postmenopausal women with osteoporosis in 11 urban areas of China. Methods A total of453 postmenopausal women with osteoporosis were enrolled in an 18-month, multi-center, randomized, controlled study. They were randomized to receive either rhPTH(1-34) 20 μg(200 U) daily for 18 months, or elcatonin 20 U weekly for 12 months. Lumbar spine ( L1-4) and femoral neck bone mineral density (BMD), fracture rate, back pain as well as biochemical markers of bone turnover ( serum bone-specific alkaline phosphatase was measured by radioimmunoassay; C-telopeptide/ creatinine ( CTX/ Cr) measured by quantitative sandwich enzyme-linked immunosorbent assay) at 6, 12, and 18 months. Adverse events were recorded. Results rhPTH(1-34) increased lumbar BMD more significantly than that did by elcatonin at 6 months( M6), 12 months (M12), and 18 months(M18; 4. 3% vs 1. 94% , 6. 8% vs 2. 72% , 9. 51% vs 2. 86% , P<0. 01). There was only a small but significant increase of femoral neck BMD at M18(2. 64% , P<0. 01) in rhPTH(1-34) groups. There were greater increases in bone turnover markers in the rhPTH(1-34) group than in the elcatonin group at M6, M12, and M18[serum bone-specific alkaline phosphatase(BSAP) 93. 67% vs -3. 56% , 117. 78% vs -4. 12% , 49. 24% vs-5. 81% , P<0. 01; urinary CTX/ Cr 250% vs -29. 5% , 330% vs -41. 4% , 273 % vs -10. 6% , P<0. 01]. rhPTH (1-34) showed similar effect of pain relief as elcatonin. The incidence of clinical fractures was 5. 36% (6 / 112) in elcatonin group and 3. 23% ( 11 / 341 ) in rhPTH ( 1-34 ) group ( P = 0. 303 ). Both treatments were well tolerated. Hypercaluria(9. 38% ) and hypercalcemia(7. 04% ) in rhPTH(1-34) group was transient and caused no clinical symptoms. Pruritus(8. 21% vs 2. 68, P=0. 044) and redness of injection site(4. 40% vs 0, P=0. 024) were more frequent in rhPTH(1-34). Nausea / vomiting(16. 07% vs 6. 16% , P = 0. 001) and hot flushes(7. 14% vs 0. 59% , P<0. 001) were more common in elcatonin group. Conclusion rhPTH(1-34) treatment was associated with greater increases in lumbar spine BMD and bone formation markers. It could increase femoral BMD after 18 months treatment. rhPTH(1-34) could ameliorate back pain effectively. The results of the present study indicate that rhPTH(1-34) is an effective, and safe agent in treating postmenopausal women with osteoporosis.
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BACKGROUND:Adiponectin and periodontal disease are closely related with type 2 diabetes. OBJECTIVE:To detect the expression of adiponectin in periodontal tissue of Kunming mice of diabetes periodontitis, and explore the effects on periodontal tissue pathology and prognosis. METHODS:Sixty 3-week-old Kunming mice were divided into three groups according to the different modeling methods:control group (normal feeding), diabetes group (diabetic model was established by injection of al oxan), diabetes and periodontitis group (periodontitis model was established by local ligation and bacteria developed). Each group contained 20 rats. RESULTS AND CONCLUSION:At 20 days after modeling, the blood glucose, fasting insulin and insulin resistance index of mice in the diabetes group were higher than that in the control group (P<0.05). ELISA, RT-PCR and western blot analysis results showed that, adiponectin gene and protein expression levels in periodontal tissues were the highest in the control group, then in the diabetes group, and the lowest in the diabetes and periodontitis group, at 1, 3, 6, months postoperatively, respectively (P<0.05). The periodontal gum tissue inflammation and histopathological changes were observed at 1, 3, 6, months postoperatively. The results showed that, the inflammation in periodontal tissues was the most obvious in the diabetes and periodontitis group, and was visible in the diabetes group, but the inflammation was not present in the control group. Experimental findings indicate that, the down-regulation of adiponectin expression in the periodontal tissue is one of the important factors that trigger and aggravate the onset of periodontitis.
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Objective To evaluate the bactericidal effect of diode laser on Porphyromonas gingivalis (Pg),and to explore an optimized protocol for a safe dose of photodynamic therapy (PDT) to eliminate periodontal pathogens as well as the impact on the implant surfaces,so as to provide theoretical and experimental basis for PDT in periimplantitis therapy.Methods Artificial in vitro models were formatted by culturing Pg standard strain and ITI (International Team for Implantology) implants together in CDC broth.Then artificial in vitro models were treated by different doses of hematoporphyrin monomethyl ether (HMME) and different energy density of laser (EDL) for 60 s.The cultures were counted by colony form unit (CFU),and SPSS 17.0 statistical software was used for data statistical analysis to select the best EDL and HMME dose.Finally,ITI implants were observed by scanning electron microscope (SEM) to evaluate the impact of HMME-PDT on Pg of implant surfaces.Results When EDL was 12 J/cm2 and mass concentration of HMME was 25 μg/ml,SEM observations showed that PDT could effectively kill Pg ((13.00±5.00) CFU)without damaging the implant surfaces.Conclusions PDT therapy combining 630 nm diode laser with photosensitizer HMME have good bactericidal effect on Pg,and the EDL and HMME dose is as small as the clinical applicable safe dose.
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BACKGROUND:Insulin-like growth factor-1 can promote mitosis of fibroblasts as wel as periodontal cellgrowth, differentiation and synthesis of extracelular matrix. OBJECTIVE: To observe the effects of chitosan/colagen composite scaffold carrying insulin-like growth factor-1 on proliferation of human periodontal ligament cels. METHODS: The human periodontal ligament cels were seeded on chitosan/colagen composite scaffold carrying insulin-like growth factor-1 and ordinary colagen scaffold. The release of recombinant human transforming growth factor-β1 was detected at 1, 24 hours and 1 week after culture; celladhesion and proliferation were detected at days 1, 7 and 28. RESULTS AND CONCLUSION:The release rate of recombinant human transforming growth factor-β1 in the composite scaffold was significantly lower than that in the ordinary colagen scaffold at 1, 24 hours and 1 week after cellseeding (P < 0.01). The celladhesion and proliferation showed no difference between two groups at day 1 after cellseeding, but became significantly higher in the composite scaffold than that in the ordinary colagen scaffold at days 7 and 28 (P < 0.01). These findings indicate that chitosan/colagen composite scaffold carrying insulin-like growth factor-1 can significantly promote the proliferation of the human periodontal ligament cels.