MiR-34a Inhibits Spinal Cord Injury and Blocks Spinal Cord Neuron Apoptosis by Activating Phatidylinositol 3-kinase (PI3K)/AKT Pathway Through Targeting CD47.

OBJECTIVE: Dysregulation of miR-34a has been reported for its implication in neuronal development. This study aims to explore the effect and possible mechanism of miR-34a on neuron apoptosis induced by Spinal Cord Injury (SCI). MATERIALS AND METHODS: SCI model was established using Allen's weight-drop method and rats in the sham group were performed with laminectomy without weight-drop injury. Basso Bcattie Bresnahan (BBB) rating scale was applied to evaluate the locomotor function of rats. Pathological changes of spinal cord tissues in SCI rats were observed after hematoxylin and eosin (HE) staining. Rats were separately injected with miR-34a agomir, miR-34a agomir NC, si-CD47 and si- CD47 NC before their spinal cord tissues were collected for terminal-deoxynucleoitidyl Transferase Mediated nick end labeling (TUNEL) staining. Expressions of miR-34a, si-CD47, apoptosis related proteins and AKT pathway related proteins were measured by quantitative reverse transcription- polymerase chain reaction (qRT-PCR) and western blot. RESULTS: SCI rat models were successfully established evidenced by decreased BBB scores and HE staining. Injection of miR-34a agomir and/or si-CD47 could suppress neuron cell apoptosis, with deceased apoptotic index (AI) and pro-apoptotic protein (cleaved caspase-3 and Bax) levels, and increased expressions of anti-apoptotic proteins (Bcl-2 and Mcl-1). Phosphorylated levels of phatidylinositol 3-kinase (PI3K) and AKT were further increased in rats injected with miR-34a agomir and si-CD47, compared with miR-34a agomir or si-CD47 injection alone. CONCLUSION: MiR-34a can downregulate CD47 expression to activate PI3K/AKT signal pathway, and thus inhibit SCI induced spinal neuron apoptosis.

[Endophytic bacterial diversity in Codonopsis pilosula, Ephedra sinica, and Lamiophlomis rotate: a study with LH-PCR].

To investigate the endophytic bacterial diversity in the three medicinal plant species Codonopsis pilosula, Ephedra sinica, and Lamiophlomis rotata in Ganzi of Sichuan, Southwest China, the total DNA of the three species were extracted by stringent surface sterilization, and studied with length heterogeneity-PCR (LH-PCR) method. For the same plant species, their root-, stem-, and leaf LH-PCR profiles were in a high level of similarity, with little differences in band richness. However, there existed great differences in the LH-PCR profiles among different plant species. C. pilosula had the biggest band richness, followed by E. sinica, and L. rotata. In the three plant species, the endophytic bacteria with an approximately 474 bp DNA length were dominant. The endophytic bacterial diversity of the plants was negatively correlated with rhizosphere soil available phosphorus content, but positively correlated with rhizosphere soil pH. Elevation and rhizosphere soil total nitrogen content were the important environmental factors affecting the distribution of enophytic bacteria in these plant species. The information of population diversity obtained from LH-PCR could more intuitively reflect the differences of bacterial diversity among different plant species, and thus, LH-PCR would be available to be used for analyzing the endophytic bacterial diversity in medicinal plants, providing information and guidance for the further isolation of microbial resources.

[Screening of antifungi endophytic actinomyces strains from salvia przewalskii in Tibean Plateau].

Twenty-four endophytic actinomycetes strains were isolated from the Salvia przewalskii in Tibetan Plateau of China by tablet coating method. Fusarium moniliforme, Helminthosporium turcicum and Bipolaris maydis were selected as indicator fungi to test the antimicrobial activities of these endophytic actinomycetes by tablet confrontation method. The results showed that 21 strains can produce antimicrobial substances which accounts for 85.7% of the total separates number. Four strains of endogenous actinomyces have more obvious antifungi activity. According to results of morphology and culture properties and 16S rDNA sequences of endophytic actinomyces, it is concluded that all of the isolates were streptomycetes trains.

The Protective Effect of Sodium Hyaluronate on the Cartilage of Rabbit Osteoarthritis by Inhibiting Peroxisome Proliferator-Activated Receptor-Gamma Messenger RNA Expression

PURPOSE: The purpose of this study was to study the protective effect and influence of sodium hyaluronate (Na-HA) on mRNA expression of peroxisome proliferators-activated receptor gamma (PPAR-gamma) in cartilage of rabbit osteoarthritis (OA) model. MATERIALS AND METHODS: Forty eight white rabbits were randomly divided into A, B, and C groups. Group A was normal control group, B and C groups underwent unilateral anterior cruciate ligament transection (ACLT). The rabbits in group B were injected normal saline after ACLT; and Group C received intraarticular1% sodium hyaluronate (HA) injection 5 weeks after surgery, 0.3 mL once a week. At 11th week after surgery, all the rabbits were sacrificed. The cartilage changes on the medial femoral condyles were graded separately. Cartilage sections were stained with safranin-O and HE, and messenger RNA (mRNA) expression of PPAR-gamma was detected by using real time polymerase chain reaction (Real Time-PCR). RESULTS: Cartilage degeneration in group B was significantly more severe than in A and C injection group. The grey value of Safranin-O of B group was higher than A and C groups. Expression of PPAR-gamma mRNA in group B was higher than group A and C. CONCLUSION: This study shows that Na-HA has a protective effect on articular cartilage degeneration, and the inhibitory effect on the PPAR-gamma mRNA expression may be one of therapeutic mechanism of Na-HA.

Comparison of therapeutic effect between percutaneous vertebroplasty and kyphoplasty on vertebral compression fracture / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To compare the clinical efficacy of percutaneous vertebroplasty (PVP) with percutaneous kyphoplasty (PKP) in the treatment of vertebral compression fracture (VCF).</p><p><b>METHODS</b>Ninety-eight patients with VCF were treated by PVP (n=42) or PKP (n=56). The anterior midline and posterior heights of vertebrae body, preoperative and postoperative visual analogue scale (VAS), operation time and amount of blood loss were compared between 2 groups.</p><p><b>RESULTS</b>There was statistical difference in vertebral height between two groups (P < 0.01). No significant difference was seen in VAS, operation time and blood loss between two groups (P < 0.05).</p><p><b>CONCLUSIONS</b>PKP and PVP have the similar therapeutic efficacy in treatment of VCF with minimal invasion, less operation time and blood loss. However, PKP is superior in the recovery of vertebral height.</p>

Effect of allograft compound vertebra on vertebral reconstruction in rabbits / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To study the effect of allograft compound vertebra on vertebral reconstruction in rabbits so as to provide biomechanical direction for manufacturing and selecting vertebral reconstruction materials.</p><p><b>METHODS</b>Twenty-five healthy New Zealand white rabbits were divided randomly into three groups: normal group (Group A, n equal to 5),iliac bone graft group (Group B, n equal to 10) and allograft compound vertebra group (Group C, equal to 10). After C4 was resected, iliac bone implantation and allograft bone cage transplantation were fulfilled in Group B and Group C, respectively. Every 5 rabbits from Group B and Group C were selected to test the biomechanical strength and biological activity one and two months postoperatively.</p><p><b>RESULTS</b>No significant statistical difference was found between Group A and Group C one and two months postoperatively (P larger than 0.05). The biomechanical strength of Group B was much weaker than that of Group A and Group C one month postoperatively (P less than 0.05), but at two months postoperatively, no statistical difference was found among the three groups. The biological activity and vertebral moulding ability of Group C were better than those of Group B at one and two months postoperatively.</p><p><b>CONCLUSIONS</b>Compound vertebra, which is made up of allograft cortical bone cage and autogenous cancellous bone, shows instantaneous and permanent biomechanical stability and biological activity, therefore, it is an ideal material for vertebral reconstruction.</p>

Comparison of therapeutic effect between percutaneous kyphoplasty and pedicle screw system on vertebral compression fracture / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To compare the clinical efficacy of percutaneous kyphoplasty (PKP) with pedicle screw system (PS) in the treatment of vertebral compression fracture(VCF).</p><p><b>METHODS</b>Eighty-six patients with VCF were treated either by PKP (Group A, n equal to 30) or PS (Group B, n equal to 56). The anterior, intermediate, and posterior heights of the vertebrae body, visual analogue pain scale (VAS) before and after operation, the duration of operation, and amount of blood loss between two groups were compared.</p><p><b>RESULTS</b>No statistical difference was noted regarding the vertebral height between two groups. Significant difference was seen in VAS, duration of operation and amount of blood loss between the two groups (P less than 0.01).</p><p><b>CONCLUSIONS</b>Percutaneous kyphoplasty has the similar therapeutic efficacy with pedicle screw system in treatment of VCF with a minimal invasion, less operation time and blood loss. For those with posterior wall destruction, PS is deemed favorable.</p>

Biomechanical analysis of fracture fixation with external fixator in vivo / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the different ways of measuring the main axial strain during treatment with an external fixator and to find the suitable compression loaded by the external fixator at an early stage.</p><p><b>METHODS</b>Eighteen healthy big-ear rabbits were randomly divided into two groups according to different measuring methods: Group A and Group B. In Group A, a strain gauge was affixed to the external tibial cortex with 502 glue, and in Group B, a bone cement-coated strain gauge was installed on the internal tibial cortex. Groups A and B were divided into two subgroups A1, A2 and B1, B2, respectively, according to the pressure of half of and the same as the body weight. A Z-shaped left mid-shaft tibial osteotomy was performed and fixed by an external fixator.</p><p><b>RESULTS</b>The scaler curves of Group A changed dramatically during the early stage. The trendlines of the internal and external cortex went consistently after reaching the stable stage while the latter strain value was higher than the former. The time for Group B reaching the stable stage was short, but its absolute strain value was less than that of Group A. Before they were pressed to the stable stage, the declined speed of Subgroup A1 was more slowly than that of Subgroup A2 while the results of Subgroups B1 and B2 were same. Group A had an ascending trend after it declined while Group B didn't have. After they reached the stable stage, both Subgroups A1 and A2 had a declining trend while Subgroup A2 was more quickly than Subgroup A1, Subgroup B1 was kept at a definite level while Subgroup B2 fluctuated.</p><p><b>CONCLUSIONS</b>The axial strain under external fixator can be measured by bone cement coated-strain gauge in vivo. The data may suggest that half of the body weight load was suitable for external fixator.</p>