The objective of the study was to clone avian beta-defensin (AvBD) 5 gene from pigeon bone marrow tissues and liver tissues, to express the recombinant AvBD5 protein in E. coli, and to determine its antimicrobial activity. The mRNA of duck AvBD5 was cloned from pigeon bone marrow tissues and liver tissues by RT-PCR. In addition, phylogenetic relationships between amino acid sequence of the pigeon AvBD5, AvBDs from other avian species, and some mammalian beta-defensin-5 were analyzed. The cDNA of pigeon AvBD5 was sub-cloned into pGEX-6p-1 vector to construct recombinant plasmid pGEX-pigeon AvBD5. The recombinant protein was expressed into E. coli and purified. Antimicrobial activity and physical-chemical stability of the recombinant fusion protein were measured in vitro. The complete nucleotide sequence of both cDNAs contained 201 bp nucleotides, encoding a polypeptide of 66 amino acids. Both beta-defensins have six conserved cysteines. Phylogenetic relationships were analyzed. Both pigeon AvBDs shared the highest amino acid homology (87.9% and 78.8%) with duck AvBD5. So it was named as pigeon AvBD5alpha (bone marrow) and AvBD5beta (liver). Both recombinant plasmids were transformed into E. coli BL21 and the bacteria were induced with Isopropyl beta-D-1-Thiogalactopyranoside (IPTG). After purification, antibacterial activity of the purified was investigated. In addition, effect of ionic strength on the antibacterial activity, and hemolytic recombinant protein activity of the purified recombinant protein were investigated. A 32 kDa protein was highly expressed. Both purified recombinant pigeon AvBD5alpha and AvBD5beta exhibited extensive antimicrobial activities against 12 bacteria, including Gram-positive and Gram-negative. In high salt ions concentrations, antibacterial activity of both recombinant proteins was decreased. In addition, the hemolysis activity of recombinant protein was extremely low.
Amino Acid Sequence ; Animals ; Anti-Infective Agents ; metabolism ; pharmacology ; Avian Proteins ; biosynthesis ; genetics ; pharmacology ; Cloning, Molecular ; Columbidae ; genetics ; Escherichia coli ; genetics ; metabolism ; Molecular Sequence Data ; Recombinant Proteins ; biosynthesis ; genetics ; pharmacology ; beta-Defensins ; biosynthesis ; genetics ; pharmacology

The objective of the study was to clone avian beta-defensin (AvBD) 3 gene from goose tissues, express the recombinant AvBD3 protein in Escherichia coli, and determine its antimicrobial activity. The mRNA of goose AvBD3 was cloned from spleen and bursa of Fabricius of the gooses by RT-PCR. The sequence analysis showed that the genefragment of AvBD3 contained 182 bp, and encoded 60 amino acids. Homology analysis showed that goose AvBD3 shared the highest percentage of amino acid homology (100%) with chicken AvBD3. The cDNA of goose AvBD3 was sub-cloned into BamH I and Sal I sites of pGEX-6p-1 vector to construct recombinant plasmid pGEX-goose AvBD3. The recombinant plasmid was transformed into E. coli BL21 and the bacteria was induced with IPTG It was demonstrated by SDS-PAGE that a 31 kDa protein which was equal to goose AvBD3 protein in molecular weight was highly expressed. The purified recombinant goose AvBD3 exhibited extensive antimicrobial activity against twelve bacteria strains, including Gram-positive and Gram-negative investigated. At high salt ions conditions, antimicrobial activity of recombinant goose AvBD3 protein against both Staphylococcus aureus and Pasteurella multocida decreased significantly. In addition, hemolysis activity of the recombinant protein was extremely low, and the recombinant protein remained antimicrobial activity under different pH values.
Amino Acid Sequence ; Animals ; Anti-Bacterial Agents ; chemistry ; metabolism ; pharmacology ; Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Geese ; genetics ; metabolism ; Molecular Sequence Data ; Recombinant Proteins ; biosynthesis ; genetics ; pharmacology ; beta-Defensins ; genetics ; isolation & purification ; metabolism

Objective The finite element method was used to analyze the effect of height of bone graft on adjacent segment stress after anterior cervical decompression and fusion.Methods One healthy adult male was included in this study.A detailed,geometrically accurate three-dimensional cervical spine model had been successfully developed from computed tomography (CT) scanning of a healthy adult male.A pure moment of 1.0 N· m was applied in different directions on the upper endplate of C3 to simulate flexion,extension,left-right lateral bending,and left-right axial rotation.We did biomechanical experiment with goat cervical specimens in terms of the moment-rotation responses.The finite element (FE) model was compared and validated with the experimental data.The relevant data in the literature was also applied for comparison and validation.To construct the post-surgery model,we turned the property of disk annulus and disk nucleus into that of the cancellous bone at C4-5.The internal fixation systems were also implanted.We changed the height of bone graft in C4-5 to be 90％,150％,175％ and 200％ of the height between C4-5 pre-surgery.The finite element models were built to simulate the post-surgery scenarios with different bone graft height,respectively.A stress analysis was conducted on the bone graft and adjacent disks.Results Under different height of bone graft,the maximum yon Mises stress on C3-4 showed when the height of bone graft was 200％.The values were 0.99 MPa,0.85 MPa,0.91 MPa and 0.89 MPa in different loading condition.The values at 150％ of the height between C4-5 pre-surgery were only 81％,73％,80％ and 87％ of the values at 200％.For C5-6,the maximum yon Mises stress were 0.77 MPa,0.83 MPa,0.91 MPa and 0.81 MPa,observed at the height of bone graft was 175％ except extension.The values at 150％ of the height between C4-5 pre-surgery were only 76％,93％,86％ and 78％ of the biggest values.With regard to C4-5,the biggest yon Mises stress was 1.25 MPa,1.77 MPa,1.75 MPa and 1.81 MPa.It was observed when the height of bone graft was 200％ of the height between C4-5 pre-surgery.The values were smallest under height of 150％ of the height between C4-5 pre-surgery.The smallest values were 63％,63％,75％ and 52％ of the biggest values.The higher the bone graft was,the bigger the maximum von Mises stress on bone graft.In a word,it seems that the smallest stress was observed when the bone graft height was 150％.Concltusion The height of bone graft makes an important difference on the stress of adjacent segment after anterior cervical decompression and fusion.150％ of the height between C4-5 presurgery was proper bone graft height.In this case,the stress on the adjacent segments intervertebral disc is smaller.The probability of adjacent segments degeneration is smaller.

BACKGROUND:There is no consensus on the optimal bone tunnel position in the lateral clavicle,which guides coracoclavicular ligament reconstruction.Postoperative complications such as enlargement of the lateral clavicle bone tunnel,bone osteolysis,clavicle fracture,and failure of internal fixation are likely to occur.Bone mass density plays an important role in the strength and stability of endophytic fixation.Regional differences in the bone mass density of the distal clavicle should not be overlooked in the repair and reconstruction of acromioclavicular dislocation.Currently,there are no quantitative clinical studies in humans regarding the bone mass density of the distal clavicle. OBJECTIVE:To measure the magnitude of bone mass density in different regions of the distal clavicle by quantitative CT to provide a reference for surgeons to repair and reconstruct the coracoclavicular ligament. METHODS:101 patients undergoing quantitative CT checking in Fuyang People's Hospital Affiliated to Anhui Medical University from October to December 2022 were enrolled,from which 1 616 samples of subdivisional bone mass density of the distal clavicle were measured.For each of the quantitative CT samples,firstly,the distal clavicle was divided medially to laterally into the following four regions:conical nodal region(region A),inter-nodal region(region B),oblique crest region(region C)and distal clavicular region(region D).Secondly,each region was divided into the first half and the second half to determine eight subdivisions,then setting semiautomatic region of interest(ROI)in each subdivision:(ROI A1,A2,B1,B2,C1,C2,D1,and D2).Thirdly,each quantitative CT scan was transferred to the quantitative CT pro analysis workstation,and cancellous bone mass density was measured in the distal clavicle ROI.Finally,the clavicular cortex was avoided when measuring. RESULTS AND CONCLUSION:(1)There was no statistically significant difference in bone mineral density on the different sides of the shoulder(P＞0.05).(2)The analysis of bone mineral density in eight sub-areas of the distal clavicle A1,A2,B1,B2,C1,C2,D1,and D2 showed statistically significant differences(P＜0.05).It could be considered that there were differences in bone mineral density in different areas of the distal clavicle.After pairwise comparison,there was no statistically significant difference in bone mineral density between A1 and A2,D1 and D2,A2 and B1(P＞0.05),and there was a statistically significant difference in bone mineral density between the other sub-areas(P＜0.05).(3)The bone mineral density in the region A2 of the anatomical insertion of the conical ligament was significantly higher than that in the inter-nodular area(region B)(P＜0.05).The bone mineral density in the region A1 was higher than that in the region A2,but the difference was not statistically significant(P＞0.05).The bone mineral density in the region C1 of the anatomical insertion of the trapezium ligament was higher than that in regions C2,D1 and D2,and the bone mineral density in the inter-nodular area(region B)was significantly higher than that in regions C and D(P＜0.05).(4)These results have suggested that there are differences in bone mass density in different regions of the distal clavicle;regional differences in bone mass density in the distal clavicle during repair and reconstruction of acromioclavicular dislocation cannot be ignored.Consideration should be given not only to biomechanical factors but also to the placement of implants or bone tunnels in regions of higher bone mass density,which could improve the strength and stability of implant fixation and reduce the risk of complications such as bone tunnel enlargement,osteolysis,fracture and implant failure.