ABSTRACT
Objective:To investigate the efficacy of single locked-plate internal fixation combined with autologous iliac bone graft in the treatment of Rorabeck type II periprosthetic distal femural fracture (PDFF) after total knee arthroplasty (TKA).Methods:A retrospective case series study was made on 13 patients suffering from Rorabeck type II PDFF after primary TKA together with severe osteoporosis (T value≤ -2.5 SD) admitted to 940th Hospital of Joint Logistics Support Force of PLA from January 2016 to December 2020, including 4 males and 9 females, aged 65-85 years [(75.2±6.5)years]. All patients were treated with single locked-plate internal fixation combined with autologous iliac bone graft. Anti-osteoporosis and early standardized joint function rehabilitation were undertaken postoperatively. The operation time and intraoperative blood loss were recorded. The range of motion of knee joint was compared before operation, at postoperative 3, 6 and 12 months and at the last follow-up. The Hospital for Special Surgery (HSS) knee score was assessed at postoperative 3, 6 and 12 months and at the last follow-up to evaluate the recovery of knee joint function. The bone mineral density was reexamined at postoperative 6 months and 12 months to evaluate the therapeutic effect of anti-osteoporosis. Complications were detected as well.Results:All patients were followed up for 12-72 months [(43.2±19.9)months]. The operation time was 90-135 minutes [(103.8±12.6)minutes], with the intraoperative blood loss of 100-250 ml [(150.0±45.6)ml]. The range of motion of knee joint was (114.6±7.8)°, (90.4±8.0)°, (97.3±4.8)° and (98.1±6.3)° before operation and at postoperative 3, 6 and 12 months (all P<0.05). The HSS knee score was (80.2±2.2)points, (84.6±2.9)points and (87.3±3.3)points at postoperative 3, 6 and 12 months (all P<0.05). The knee joint function was excellent in 10 patients and good in 3 at postoperative12 months, and the excellent and good rate was 100%. The T value of bone mineral density was (-3.8±0.6)SD, (-3.4±0.6)SD and (-2.9±0.6)SD preoperatively and at postoperative 6 months and 12 months (all P<0.05). One patient experienced nonunion and was cured after secondary autologous iliac bone grafting combined with recombinant human bone morphogenetic protein-2 (rhBMP-2) bone grafting. Three patients developed venous thrombosis of lower limbs and were cured with oral administration of rivaroxaban. One patient had mild knee flexion and extension limitation and was improved after manual release under femoral nerve block anesthesia and subsequent functional rehabilitation. Conclusion:For patients with Rorabeck type II PDFF after TKA, single locked-plate internal fixation combined with autologous iliac bone graft has advantages of short operation time, few intraoperative bleeding, satisfactory knee range of motion and functional recovery as well as significant improvement of bone mineral density.
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We investigated the third-generation cephalosporins-resistant Shigella and its genotype in Ningbo,China,providing a basis for disease prevention and control.Pathogenic bacteria were analyzed by direct isolation combined with enrichment culture isolation.Antimicrobial susceptibility was determined by K-B disk diffusion method and PCR was used for detecting multidrug resistance genes like CTX-M,OXA,TEM and SHV.BLAST analysis was used to determine the genotype.Results showed that 69 strains of third-generation cephalosporins-resistant Shigella were detected by drug sensitivity screening,accounting for 74.19％ of ESBLs Shigella.Drug resistance gene CTX-M(CTM-M-1 and CTM-M-9),OXA and TEM were detected.The detection rate were 79.71％,79.01％ and 26.09％ respectively.With no CTX-M-2 and SHV,DNA sequence alignment showed CTX-M-1 group were mainly of CTX-M-15 type besides seven other types;CTX-M-9 group were mainly of CTX-M-14 type besides six other types;49 strains of OXA and 18 strains of TEM were sequenced to be type 1 (OXA-1 and TEM-1 type).The 21 Shigella strains carrying more than two drug resistance genes accounts for 30.43 ％.Shigella in Ningbo has high third-generation cephalosporins-resistance rate and many kinds of ESBLs enzymes were detected.The mainstream enzyme type was CTX-M,meanwhile they also carried a variety of drug resistance genes,which could bring difficulties to disease prevention and control.The high carrying rate of OXA-1 type suggests that we should pay more attention.The detection rate of group B was higher than that of group D,including not only the phenotype resistance but also the drug-resistance genes;these findings will be useful in the study of the drug resistance prevalence of Shigella.
ABSTRACT
Chromogranin A (CGA)-N46, a derived peptide of human chromogranin A, has antifungal activity. To further research the active domain of CGA-N46, a series of derivatives were designed by successively deleting amino acid from both terminus of CGA-N46, and the amino acid sequence of each derivative was analyzed by bioinformatic software. Based on the predicted physicochemical properties of the peptides, including half-life time in mammalian reticulocytes (in vitro), yeast (in vivo) and E. coli (in vivo), instability index, aliphatic index and grand average of hydropathicity (GRAVY), the secondary structure, net charge, the distribution of hydrophobic residues and hydrophilic residues, the final derivatives CGA-N15, CGA-N16, CGA-N12 and CGA-N8 were synthesized by solid-phase peptide synthesis. The results of bioinformatic analysis showed that CGA-N46 and its derivatives were α-helix, neutral or weak positive charge, hydrophilic, and CGA-N12 and CGA-N8 were more stable than the other derivatives. The results of circular dichroism confirmed that CGA-N46 and its derived peptides displayed α-helical structure in an aqueous solution and 30 mM sodium dodecylsulfate, but α-helical contents decreased in hydrophobic lipid vesicles. CGA-N15, CGA-N16, CGA-N12 and CGA-N8 had higher antifungal activities than their mother peptide CGA-N46. Among of the derived peptides, CGA-N12 showed the least hemolytic activity. In conclusion, we have successfully identified the active domain of CGA-N46 with strong antifungal activity and weak hemolytic activity, which provides the possibility to develop a new class of antibiotics.
Subject(s)
Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Peptides/chemistry , Peptides/pharmacology , Amino Acid Sequence , Animals , Chromogranin A/chemistry , Circular Dichroism , Hemolysis/drug effects , Humans , Hydrophobic and Hydrophilic Interactions , Peptides/adverse effects , Structure-Activity RelationshipABSTRACT
CGA-N46 is a small antifungal-derived peptide and consists of the 31st-76th amino acids of the N-terminus of human chromogranin A. Polycistronic expression of recombinant CGA-N46 in Bacillus subtilis DB1342 was used to improve its production, but the yield of CGA-N46 was still low. In the present study, response surface methodology (RSM) was used to optimize culture medium composition and growth conditions of the engineered strain B. subtilis DB1342(p-3N46) for the further increase in CGA-N46 yield. The results of two-level factorial experiments indicated that dextrin and tryptone were significant factors affecting CGA-N46 expression. Central composite design (CCD) was used to determine the ideal conditions of each significant factors. From the results of CCD, the optimal medium composition was predicted to be dextrin 16.6 g/L, tryptone 19.2 g/L, KH2PO4·H2O 6 g/L, pH 6.5. And the optimal culture process indicated inoculation of B. subtilis DB1342(p-3N46) seed culture into fresh culture medium at 5 % (v/v), followed by expression of CGA-N46 for 56 hours at 30 °C induced by 2 % (v/v) sucrose after one hour of shaking culture. To test optimal CGA-N46 peptide expression, the yeast growth inhibition assay was employed and it was found that under optimal culture conditions, CGA-N46 inhibited the growth of Candida albican by 42.17, 30.86 % more than that in the pre-optimization conditions. In summary, RSM can be used to optimize expression conditions of CGA-N46 in engineered strains B. subtilis DB1342(p-3N46).
Subject(s)
Antifungal Agents/metabolism , Antifungal Agents/pharmacology , Bacillus subtilis/metabolism , Bacterial Proteins/metabolism , Bacterial Proteins/pharmacology , Bioengineering/methods , Biostatistics/methods , Culture Media , Yeasts/drug effectsABSTRACT
CGA-N46 is a small antifungal derived peptide and consists of the 31st to 76th amino acids of the N-terminus of human chromogranin A. Polycistronic expression of recombinant CGA-N46 in Bacillus subtilis DB1342 was used to improve its production, but the yield of CGA-N46 was still low. In the present study, response surface methodology (RSM) was used to optimize culture medium composition and growth conditions of the engineered strain B. subtilis DB1342(p-3N46) for the further increase of CGA-N46 yield. The results of two-level factorial experiments indicated that dextrin and tryptone were significant factors affecting CGA-N46 expression. Central composite design (CCD) was used to determine the ideal conditions of each significant factors. From the results of CCD, the optimal medium composition was predicted to be dextrin 16.6 g/L, tryptone 19.2 g/L, KH2PO4·3H2O 6 g/L, pH 6.5. And the optimal culture process was indicated that B. subtilis DB1342(p-3N46) seed culture was inoculated into fresh culture medium at 5% (v/v), followed by expression of CGA-N46 for 56 hours at 30°C induced by 2% (v/v) sucrose after one hour of shaking culture. To test optimal CGA-N46 peptide expression, the yeast growth inhibition assay was employed and it was found that under optimal culture conditions, CGA-N46 inhibited the growth of C. albican by 42.17%, 30.86% more than that in the pre-optimization conditions. In summary, RSM can be used to optimize expression conditions of CGA-N46 in engineered strains B. subtilis DB1342(p-3N46).
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BACKGROUND:Studies have shown that theβ-tricalcium phosphate can be combined with other macromolecular compounds to improve the mechanical strength and histocompatibility, meeting the requirements of clinical application. ＜br> OBJECTIVE:To evaluate the selection and preparation methods of composite scaffold in bone tissue engineering, and to describe the problems we are facing. ＜br> METHODS:The first author retrieved PubMed, Google Scholar, CNKI, Wanfang, and VIP databases by computer using the keywords of“β-tricalcium phosphate,β-TCP, PLGA, PLA, scaffold, prepare”in English and Chinese, respectively. ＜br> RESULTS AND CONCLUSION:β-tricalcium phosphate combined with polylactic acid-glycolic acid/polylactic acid as bone tissue engineering scaffolds has achieved a great progress. At present, the organic polymer composite scaffolds can be prepared by microsphere sintering, fiber bonding, solvent casting/particulate leaching, emulsification/freeze drying technology, gas foaming method, phase separation technology, rapid prototyping technology and electrostatic spinning method.β-tricalcium phosphate composite scaffolds with polylactic acid-glycolic acid/polylactic acid can be customizable so as to meet different requirements for bone tissue engineering, which can improve the porosity, mechanical properties and biodegradation by improving fabrication techniques and processings, ratio of raw materials and fil er proportion.
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Objective To measure the transcription level of thermostable direct hemolysin gene (TDH)in 24 strains of Vibrio parahaemolyticus.Methods Total RNA was extracted from strains of Vibrio parahaemolyticus which were isolated from patients,seafood and environment.The RNA was proved TDH positive with routine PCR method;then the real -time fluorescent quantitative PCR was carried out to obtain the cycle of threshold (Ct)of THD and internal standard of 16s rRNA.Transcription level of THD compared with 16s rRNA was designated as ΔCt which was calculated as Ct value of THD minus Ct value of 16s rRNA.Results Ct values of THD,16s rRNA and the difference between them of the 24 strains was 18.04 ~25.95,8.30 ~10.93 and 8.28 ~15.34 respectively.The difference between the maximum and the minimum of ΔCt was 7.06;the highest transcription level was 133 (ΔΔCt =27.06 )times of the lowest one.Conclusion A great difference of transcription level of THD in Vibrio parahaemolyticus has been proved and further study is needed to clarify the possible molecular mechanisms and relationship between the transcription level of THD and pathogenic mechanism.
ABSTRACT
Rehmannia glutinosa, a traditional Chinese medicine herb, is unable to grow normally in a soil where the same species has recently been cultivated. The biological basis of this so called "replanting disease" is unknown, but it may involve the action of microRNAs (miRNAs), which are known to be important regulators of plant growth and development. High throughput Solexa/Illumina sequencing was used to generate a transcript library of the R. glutinosa transcriptome and degradome in order to identify possible miRNAs and their targets implicated in the replanting disease. A total of 87,665 unigenes and 589 miRNA families (17 of which have not been identified in plants to date) was identified from the libraries made from a first year (FP) and a second year (SP) crop. A comparison between the FP and SP miRNAs showed that the abundance of eight of the novel and 295 of the known miRNA families differed between the FP and SP plants. Sequencing of the degradome sampled from FP and SP plants led to the identification of 165 transcript targets of 85 of the differentially abundant miRNA families. The interaction of some of these miRNAs with their target(s) is likely to form an important part of the molecular basis of the replanting disease of R. glutinosa.
Subject(s)
Gene Expression Regulation, Plant , MicroRNAs/genetics , Tracheophyta/genetics , Transcriptome , Computational Biology , Gene Expression Profiling , High-Throughput Nucleotide Sequencing , Molecular Sequence AnnotationABSTRACT
The ability of cationic liposomes composed of DC-Chol and cholesterol to carry pDNA into 293 T cells was investigated. Lipoplexes formed between DC-Chol/cholesterol liposomes and pDNA (encoding green fluorescent protein, GFP) were analyzed in terms of morphology observation, turbidity determination, particle size and zeta potential measurement, differential scanning calorimetry (DSC), gel retardation assay, cytotoxicity analysis in 293 T cells and transfection efficiency. The results showed that liposome preparation at or above 66.7 mol% cholesterol in formulation exhibited a calorimetric transition caused by anhydrous cholesterol domain at about 41°C. In comparison with the control, DOPE-containing liposomes, DC-Chol/cholesterol carriers showed more stable particle size, lower turbidity, higher activity for transfecting cells in the presence of high concentration serum (50% FBS), primarily due to the neutral domain formation by increasing mole ratios of cholesterol in formulation, as well as relatively lower cytotoxicity. Based on the results, it is suggested that incorporating high contents of cholesterol might be a potentially applicable method for various kinds of cationic lipids to obtain the gene carriers with high capability for in vivo transfection.
