Design principle and research development of artificial lumbar disc prosthesis / 中国组织工程研究

BACKGROUND:Artificial Lumbar disc replacement as a new choice for the treatment of degenerative disc disease has aroused widespread concern by clinicians because of the preservation of lumbar vertebra’s biomechanical characteristics during pain eliminating. While the design of the prosthesis structure and material needs further study and validation. OBJECTIVE:To review the structure and material types of several newly designed artificial lumbar discs, then to discuss the trends in the optimization design of prosthesis, in order to provide instruction for the design and assessment of new lumbar artificial disc prosthesis. METHODS:The PubMed database, CNKI database and SinoMed database were searched for related articles. New articles related to artificial lumbar disc structure, material, in vivo and in vitro biomechanics were included. Repetitive studies and stale perspectives were excluded. A total of 46 articles were summarized and discussed in the end. RESULTS AND CONCLUSION:Artificial lumbar disc has developed for nearly 30 years, the design of structure and biological material has been in continuous improvement. At first, we summarized the principle and current situation in the design of movement reservation, movement constraint, instant fixation, base material, weight-bearing material and coating material of artificial lumbar disc prosthesis, then combined with the exist newly in vivo and in vitro biomechanical results to evaluate different kinds of design with the recent research trend to prospect the development of biomimetic design, material improvement, the optimization design of prosthesis and assisted devices.

Clinical application of artificial lumbar disc replacement:Present and future / 中国组织工程研究

BACKGROUND:The basic idea of artificial disc replacement is the intension to minimize the impact on adjacent segments based on the premise of stabilizing index segment, then prevent and reduce the incidence of adjacent segment degeneration. OBJECTIVE:To explore the indications and contraindications of artificial disc replacement, peri-operative economics considerations, long-term complications, as wel as the effect of artificial lumbar disc replacement combined with fusion surgery. METHODS:The PubMed database, CNKI database and SinoMed database over the past decade were searched for the related articles. The retrospective and prospective clinical trials of artificial lumbar disc replacement were included. Repetitive studies and stale perspectives were excluded. A total of 34 articles were summarized and analyzed in the end. RESULTS AND CONCLUSION:Since the first artificial lumbar disc prosthesis designed to be commercial y distributed in 1982, there have been a plenty of clinical trials on lumbar disc replacement. However, there is no answer to many problems that encountered in clinical trials. The effect of the number of replaced segment on the clinical outcomes, the effect of facet joint degeneration on the clinical outcomes, selection of the patients with the history of lumbar disc surgery, age of the patients and the rest time before disc replacement should be taken into consideration in the researches on indications and contraindications of artificial disc replacement. The intraoperative blood loss, operation time and hospital stay after replacement can be used to evaluate whether lumbar disc replacement is better than the traditional lumbar fusion surgery or not. The complications after lumbar disc replacement include heterotopic ossification, implants mechanical failure, and facet joint and adjacent segment degeneration. The combination of lumbar disc replacement and fusion surgery for the treatment of multi-segmental lumbar disc diseases can achieve complement and thus obtaining the efficacy that better than the application of one surgery alone.

Experimental study on phosphatidylinositol 3 kinase signal transduction pathway in Barrett esophagus genesis / 中华消化杂志

Objective To explore the relationship between phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt)/mammals target protein rapamycin (mTOR) signal transduction pathway and Barrett esophagus genesis.Methods A total of 140 rats were divided into sham operated group (n=10),iron group (n =10),esophageal duodenal side anastomosis group (n =30),esophageal duodenal side anastomosis plus iron group (n-30),esophageal gastric duodenal side anastomosis group (n=30) and esophageal gastric duodenal anastomosis plus iron group (n=30).In the end,10 normal esophagus tissue specimens,62 reflux esophagitis tissue specimens and 34 Barrett's esophagus tissue specimens were obtained.The expression levels of epidermal growth factor receptor (EGFR),Akt,phospho Akt (p-Akt),phospho-mTOR (p-mTOR) protein were detected by immunohistochemistry.Single factor analysis of variance,SNK between two groups and nonparametric correlation analysis were performed for statistical analysis.Results The protein expression levels of EGFR,Akt,p-Akt,p-mTOR in Barret(s esophagus tissues were higher than those in reflux esophagitis tissues and normal esophagus tissues (EGFR 0.1799±0.0367 vs 0.0438±0.0025 and 0.0277±0.0069,q=6.79,4.13; Akt 0.1874±0.0250 vs 0.0986±0.0093 and 0.0383±0.0048,q=6.51,3.56; p-Akt 0.1418±0.0130 vs 0.0592±0.0027 and 0.0281 ±0.0017,q=7.68,3.99; p-mTOR 0.1591±0.0275 vs 0.0674 ±0.0059 and 0.0112±0.0017,q=5.62,4.11; all P＜0.05).The protein expression levels of EGFR,Akt,p-Akt,and p-mTORin reflux esophagitis tissues were higher than those in normal esophagus tissues(q=4.67,4.29,4.27,4.03; all P＜0.05).Conclusion PI3K/Akt/mTOR signal transduction pathway were activated in reflux esophagitis and Barrett's esophagus,which provided theoretical basis for clinical multi-target treatment for diseases.

The role of p38 signal transduction pathway in the pathogenesis of Barrett esophagus / 中华消化杂志

Objective To investigate the role of deoxycholic acid (DCA) in the pathogenesis of Barrett esophagus.Methods Normal human esophageal mucosal epithelial cells were cultured in vitro with defined keratinocyte serum-free media (D-KSFM).The cultured cells were treated with different concentrations of DCA and specific p38 mitogen activated protein kinase (MAPK) inhibitor. The expression of p38,phosphorylated p38 (p-p38) and caudal-related homeodomain transcription 2 (CDX2) at protein level were assessed by Western blot.The correlation between p-p38 and CDX2 was analyzed.The data were analyzed by one way ANOVA and LSD test.Results After being cultured with DCA for 24 h,the expression of p-p38 and CDX2 increased along with the increasing of DCA concentration.Compared with the control group (p-p38 was 13.7％ ± 1.0％ and CDX2 protein was 0),the difference was statistically significant (P＜ 0.05).When DCA was at 500 μmol/L,the expression of p-p38 and CDX2 reached the highest level (44.0％ ± 1.7％ and 8.59± 1.25).After pretreated with SB203580 for two hours and then 500 μmol/L DCA was added into cell culture,both expression level of p-p38 and CDX2 decreased compared with 500μmol/L DCA group (p-p38:28.3％ ±2.2％ vs50.5％±9.5％,CDX2:0.94±0.13 vs 2.31±0.41) after 24 h.Conclusions DCA can induce the expression of CDX2 in normal human esophageal mucosal epithelial cells,which is related with the activation of p38.The phosphorylation of p38 maybe involved in the pathogenesis of Barrett esophagus.

DNA demethylation of ARHI and cell apoptosis in pancreatic cancer / 中华胰腺病杂志

H1 gene inactivation.Demethylation agent inhibits human pancreatic cancer cell line growth in association with ARH1 re-expression and reduced p-stat3 expression.