ABSTRACT
Objective The feasibility of predicting the B-cell epitopes of human Neutrophil Gelatinase-Associated Lipocalin (NGAL) was discussed by applicating bioinformatics technology.Linear epitope molecules that have diagnostic value were screened and these recombinant linear multi-epitope peptides were constructed,and expressed.The immunogenicity of the recombinant linear multi-epitope peptides were also identified.Methods NGAL amino acid sequence was got from GenBank in the Department of Clinical Laboratory of the Second Affiliated Hospital of Nanjing Medical University in July 2015,the Predicted,ABCpred,BepiPred,BcePred,and Lasergene softwares were used to predict the linear B cell epitope prediction.The predict epitopes were constructed and prokaryotic expressed,and then the single epitope antigens which could reacted with commercially available polyclonal NGAL antibody were screened out by Western blot.Finally,the multi-epitope peptide was constructed,expressed,and identified through immunoreactions.Results Eight possible epitopes were obtained after prediction.pET32a-N1-N8 prokaryotic expression vector were used to express the predict epitopes.After purification and Western blot analysis,three of the epitopes have strong antigenicity,and then a soluble fusion protein was expressed and obtained from the multi-epitope prokaryotic expression vector pET22b-Ngal_MEP1.The fusion protein was successfully purified by Ni2 + affinity column.Western blot analysis showed that the fusion protein had a strong antigenicity.Conclusions The constructed multi-epitope linear NGAL antigen peptides can obtain high soluble expression in prokaryotic expression system,and have a strong immunoreactivity,which can be used in subsequent antibody preparation.
ABSTRACT
Objective: To compare the peri-implant tissue stability between immediate implant and delayed implant in maxillary anterior region after loading 2 years.Methods: In the study, 38 patients with single anterior tooth loss in the Second Clinical Division of Peking University School and Hospital of Stomatology from October 2010 to December 2011 were enrolled , and 43 implants were inserted .The gin-gival contour was induced using implant-supported temporary crowns prior to restoration till permanent prostheses delivered .The gingival papilla height , labial gingival margin level and peri-implant bone level were measured immediately after the permanent restoration and 2 years later .Results: In the study , 16 patients were treated by immediate implant for 17 implants;22 patients were treated by delayed im-plant for 26 implants .The implant stability quotient ( ISQ ) value of the 2 groups showed no significant difference before permanent restoration (P>0.05).In all the cases after loading 2 years, the average mesial gingival papilla height in the implant area of the immediate group and delayed group increased by (0.15 ±0.42) mm and (0.06 ±0.65) mm, respectively;the distal gingival papilla height increased by (0.06 ±0.50) mm and (0.02 ±0.57) mm respectively;while the labial gingival margin level shrinka-ges were (0.15 ±0.23) mm and (0.15 ±0.46) mm, respectively.The peri-implant bone losses in the mesial side were (0.67 ±0.35) mm and (0.69 ±0.49) mm, respectively, while in the distal side were (0.73 ±0.31) mm and (0.75 ±0.48) mm, respectively.All these indicators showed no significant difference between the 2 groups ( P>0 .05 ) .Conclusion:Both the cases obtained optimizer results after loading 2 years, and the soft and hard tissues around the implant were very stable , which means that both the protocols can achieve reliable therapeutic effects .If we can handle the indications , immediate implant for anterior teeth shows similar efficacy with delayed implant in the short term .But immediate implant in terms of shortening the course of treatment is clearly superior to delayed implant .
ABSTRACT
Objective:To analyze the biomechanics trait of one-piece computer aided design and com-puter aided manufacture ( CAD/CAM ) zirconia post and core by the three-dimensional finite element . Methods:The three-dimensional finite element models of three upper central incisors restored with one -piece CAD/CAM zirconia post and core ( group 1 ) , refabricated zirconia post and hot-pressed porcelain core ( group 2 ) , and cast gold alloy post and core ( group 3 ) were built by geometry method respectively . 100 N vertical loading through the central incisor models long axis and 100 N loading along directing at an angle of 45°with the models long axis were used to imitate the central incisor stress state in biting and mandible physiological protraction movement .Results:Under vertical loading , the restored teeth without dentin ferrule, the maximum Von-Mises stress value of the tooth root in group 1 was the least(11.02 N), which was the largest (13.17 N)in group 2.The stress became weaker from the upper to the lower of the tooth root.The maximum Von-Mises stress value of the tooth root , post and core became smaller while the restored teeth with the 2.0 mm high dentin ferrule.Under directing at an angle of 45°loading, without the design of dentin ferrule in the restored teeth , the maximum Von-Mises stress value of the post and core in group 1 was the greatest(20.45 N), while that stress of post and core in group 3 was the smallest (13.61 N).With 2.0 mm high dentin ferrule design in the restored teeth , the tooth root stress became weaker.The maximum Von-Mises stress value of the tooth root was the greatest (14.10 N) in group 3, but which was the lowest (13.38 N) in group 1.Conclusion:The results of the three-dimensional finite element analysis infers that one-piece zirconia post and core restoration is more beneficial to disperse the bite force than the prefabricated zirconia post and the cast gold alloy post and core .The one-piece of zirconia post and core is good to protect the teeth and keep the restoration intact .