Experimental Study of the Effects of Hypoxia Simulator on Osteointegration of Titanium Prosthesis in Osteoporotic Rats

Abstract

Purpose: Poor osseointegration is the key reason for implant failure after arthroplasty, whether in osteoporotic or normal bone conditions. To date, osseointegration remains a major challenge. Recent studies have shown that deferoxamine(DFO) can accelerate osteogenesis by activation of the hypoxia signal pathway. The purpose of this study is to test the following hypothesis: after knee replacement, intra-articular injection of DFO will promote osteogenesis and osseointegration with titanium prosthesis in the bones of osteoporotic rats.Materials and Methods: 90 female sprague-dawley rats were used for the experiment. Ovariectomy and knee arthroplasty were performed. Then, the rats were randomly divided into DFO and control group(n=40 per group). The two groups were treated by intraarticular injection of DFO and saline respectively. After 2 weeks, polymerase chain reaction(PCR) and immunohistochemistry were used to evaluate the levels of HIF-1a, VEGF and CD31. After 12 weeks, the specimens were examined by micro CT, biomechanics and histopathology to evaluate osteogenesis and osseointegration.Results: The results of PCR showed mRNA levels of VEGF and CD31 in DFO group were significantly higher than those in control group. The immunohistochemistry results indicated positive cell expressions of HIF-1a, VEGF and CD31 in DFO group were also higher. Compared to control group, the microCT parameters of BMD, BV/TV, TB.N, TB.Th were significantly higher. The maximal pull-out force and the bone-to-implant contact (BIC) value were also higher . Conclusions: The local administration of DFO which is used to activate HIF-1a signaling pathway can promote osteogenesis and osseointegration with the prosthesis in osteoporotic bone.

Research Progress on Mechanism of Acupuncture Treatment for Insomnia

“…Five-hydroxytryptamine (5-HT) has a dual regulating effect on sleep-wake cycle, which can not only promote awakening, but also a necessary condition for non-rapid eye movement sleep, so 5-HT is one of the hubs of sleep and awakening [13]. 5-hydroxyindoleacetic acid (5-HIAA) is a metabolite of 5-HT, and the increase of 5-HIAA content indirectly indicates the increase of 5-HT production and metabolism [14]. Luo Benhua et al [15] found that the content of 5-HT and 5-HIAA in hippocampus of PCPA insomnia rats was significantly lower than that of normal rats (P&lt; After acupuncture treatment, the insomnia symptoms of rats were significantly improved, and the contents of 5-HT and 5-HIAA in hippocampus were significantly increased, which were significantly different from those before treatment (P<0.05).…”