Objective To assess whether highly cross-linked polyethylene liners are superior to conventional polyethylene liners in total hip arthroplasty (THA).Methods Randomized controlled trials (RCTs) of highly cross-linked and conventional polyethylene liners in THA were retrieved from MEDLINE,PubMed,EMBASE,Cochrane Central,CBMdisc,CBM,and VIP.Until April 2012,reference lists of the included articles and related reviews were manually searched as supplements.Meta analysis was performed with RevMan 5.1.Mean difference (MD) was used to assess the linear wear rate in highly cross-linked group versus conventional group.Odds ratio (OR) was used to estimate the osteolysis and revision incidence in the two groups.Results Meta analysis indicated that the two-dimensional linear wear rate [MD =-0.08,95％ CI (-0.1,0.06),P ＜ 0.05],three-dimensional linear wear rate [MD=-0.15,95％CI (-0.22,0.08),P＜0.05],volumetric wear rate [MD=-53.03,95％ CI (-84.39,-21.67,P＜0.05],total linear wear [MD=-0.19,95％CI (-0.23,-0.15),P＜0.05],and osteolysis incidence [OR =0.23,95％ C1 (0.13,0.39),P ＜ 0.05] were significantly reduced in highly cross-linked group than in conventional group.There were no statistical differences between the two groups concerning the creep value of the polyethylene liners and revision incidence.Conclusions Highly cross-linked polyethylene liners for primary THA present a low incidence of wear and osteolysis.As the number and quality of the included studies are limited,a long-term follow-up of more large-sample and high-quality RCTs are needed to evidence the outcome.

BACKGROUND: Disuse osteoporosis is bone mass loss caused by muscular inactivity and reduced weight bearing. OBJECTIVE: To observe bone structure and mineral matter content as well as bone biomechanicai performance change at different time points during the development of disuse osteoporosis. DESIGN, TIME AND SETTING: The present randomized, controlled, and self-controlled animal experimental was performed in the General Hospital of Tianjin Medical University between September and November 2003. MATERIALS: A total of 55 male Japanese rabbits, aged 8 months, weighing 2.5-3.0 kg were enrolled for this study. METHODS: The right hind limbs of 50 randomly selected rabbits were immobilized by cast (experimental sides). The corresponding left hind limbs were untouched (control sides). The remaining 5 rabbits were raised for 3 months, and their bilateral hind limbs were used for controls. Ten rabbits were sacrificed by intravenous injection of air at each time point (2, 4, 6, 8, and 12 weeks after immobilization). MAIN OUTCOME MEASURES: Mechanical test was performed on bilateral tibiofibula for determination of calcium content. Hematoxylin-eosin staining and Masson staining of bilateral metatarsal bones were performed for histological observation. RESULTS: There was significant difference in indices of tibiofibula on the experimental sides, including maximum loading, elastic modulus, and calcium content among different time points, while significant difference also existed between the experimental side and the blank controls (P＜0.05). There was no significant difference in above-mentioned indices between the control side and blank controls as well as between control sides (P＞0.05). The experimental side limbs exhibited thinned cortical bone, increased pores, sparse and fine trabecular bone with several fragmentations, expanded medullary cavity, and increased osteoblasts. Masson staining results demonstrated that with disuse time going, collagen was decreasingly formed. The control side and blank control limbs showed thickened metatarsal bone and cortical bone, a few pores, and compactly arranged trabecular bone with normal structure. CONCLUSION: During the development of disuse osteoporosis, calcium content and the entire biomechanical performance are gradually and slowly decreased to accommodate the stress environment and functional status.

The incidence rate of anxiety and depression is significantly higher in patients with inflammatory bowel diseases (IBD) than in the general population. The mechanisms underlying dextran sulfate sodium (DSS)-induced depressive-like behaviors are still unclear. We clarified that IBD mice induced by repeated administration of DSS presented depressive-like behaviors. The paraventricular thalamic nucleus (PVT) was regarded as the activated brain region by the number of c-fos-labeled neurons. RNA-sequencing analysis showed that lipocalin 2 (Lcn2) was upregulated in the PVT of mice with DSS-induced depressive behaviors. Upregulating Lcn2 from neuronal activity induced dendritic spine loss and the secreted protein induced chemokine expression and subsequently contributed to microglial activation leading to blood-brain barrier permeability. Moreover, Lcn2 silencing in the PVT alleviated the DSS-induced depressive-like behaviors. The present study demonstrated that elevated Lcn2 in the PVT is a critical factor for DSS-induced depressive behaviors.
Mice ; Humans ; Animals ; Lipocalin-2/genetics* ; Midline Thalamic Nuclei ; Brain ; Inflammatory Bowel Diseases ; Proto-Oncogene Proteins c-fos ; Mice, Inbred C57BL