Xenogeneic/Allogeneic bone materials are among the hot research interests of biological scaffolds.These materials are ideal materials for repairing bone defects because they have the structure and morphology of the natural bones,are able to be degraded and absorbed in the body,and are less immunogenic through appropriato treatment.Through further modification with biological molecules such as growth factors,they could provide a better microenvironment for the bone cells to grow into and fully differentiate.This article summarizes the factors affecting the immunogenicity of xenogeneic/allogeneic bone and the methods of removing immunogenicity.Advances in sintered bone materials,defatted bone materials,deproteinated bone materials,decalcifying bone materials,and composite materials are reviewed in greater details.

The etiology in Basic of TCM was six exopathogens (wind, cold, summer heat, wet, dryness, and fire),seven emotions, blood stasis, phlegm retention, improper diet, exhaustion, infectious damp heat, trauma and bitten by animal and insect. Through years of observation, we found that some diseases could not be explained by such etiologies and thus put forward some new etiologies, including pollution poison gas, drugs, chemicals and radiation. These new etiologies had some significance in improving TCM theories and guiding clinical practice.

ObjectTo establish HPLC fingerprint for the identification and evaluation of Caulis Spatholobi. Methods HPLC system was used to obtain the chromatograms of Caulis Spatholobi and the clustering analysis was applied for data analysis. Results There are 11 peaks in total, among them five are common, the relative retention time is 0.046, 0.664, 1.000, 1.198, 1.383, the relative peak area is 0.819,0.221,1.000,0.331,0.458. There was obvious difference among chromatographic fingerprints of Caulis Spatholobi and its easily-confused species. The 11 measured peaks could be used as the fingerprint features. Conclusion Chromatographic fingerprint of HPLC can be used for identifying the Caulis Spatholobi and its easily-confused species.

Nano-hydroxyapatite biomimetic bone materials have become a hotspot in the field of tissue engineering research due to the similarity of the structure and composition to natural bone. This article describes a variety of preparation of nano-hydroxyapatite and synthesis of nano-hydroxyapatite composite, as well as the properties of nano-hydroxyapatite composite materials. Through surface-modification nanohydroxyapatite composite materials will have a potential application foreground including bone defects repair,drug carrier for cancer treatment. In this paper, research progress of nano-hydroxyapatite biomimetic bone materials in recent years were reviewed.

Objective To evaluate the effects of cerebral ischemia/reperfusion or/and icariin on expression of cytochrome C oxidase subunitⅡ(COⅡ) mRNA in mice. Methods The mouse model of transient cerebral ischemia/reperfusion was made by bilateral occlusion of common carotid arteries and ischemic hypotension/reperfusion. The mice were divided into several groups at random: normal control group, model group and icariin preventive treatment group (100 mg/kg). The changes in expression levels of COⅡ mRNA in mice cerebral tissue were detected by RT-PCR at different time points. Results The levels of CO Ⅱ mRNA in model group had no significant changes at 1 h and 24 h after cerebral ischemia/reperfusion as compared with that in control group, but decreased remarkably at 3 h (P

ObjectiveTo investigate the changes of the opposite structures with the minimally invasive transforaminal lumbar interbody fusion and unilateral fixation.MethodsFrom January 2009 to January 2010,a total of 34 patients with low back pain underwent the minimally invasive transforaminal lumbar interbody fusion and unilateral internal fixation were retrospectively analyzed.Visual analogue scale (VAS) and Japanese Orthopaedic Association(JOA) low back pain scores were used to assess the outcome of the surgery.All patients were followed up for at least 6 months after surgery.The opposite structures of the segments with fusion and unilateral fixation were investigated with CT scans.CT imaging of the patients with opposite low back pain after surgery were analyzed for exploring possible causes of the pain.ResultsThere were significant differences between the pre- and post-operation in VAS and JOA scores(P＜0.01).Four patients met pain in the opposite lumbosacral area after surgery.The CT scans showed that the rebuilding of the lordosis and disc height of the opposite side were more difficult.Rotation could happen in the progress of surgery.For the 4 patients with opposite low back pain after surgery,the insufficiency of the rebuilding of lordosis and disc height of the opposite side,and the rotation between the vertebras were more obvious,and changes were observed in the opposite facet joint on the post-operational CT scan of one patient.Conclusion The minimally invasive transforaminal lumbar interbody fusion and unilateral fixation are effective for patients with low back pain.It's important to pay more attention to the rebuilding of the lordosis and disc height of the opposite side,and the rotation of the vertebras in the surgery.

Genetic modification technology is a new molecular tool for targeted genome modification. It includes zinc finger nucleases (ZFN) technology, transcription activator-like effector nucleases (TALEN) technology and clustered regularly interspaced short palindromic repeat (CRISPR)-associated (Cas) (CRISPR-Cas) nucleases technology. All of these nucleases create DNA double-strand breaks (DSB) at chromosomal targeted sites and induce cell endogenous mechanisms that are primarily repaired by the non-homologous end joining (NHEJ) or homologous recombination (HR) pathway, resulting in targeted endogenous gene knock-out or exogenous gene insertion. In recent years, genetic modification technologies have been successfully applied to bacteria, yeast, human cells, fruit fly, zebra fish, mouse, rat, livestock, cynomolgus monkey, Arabidopsis, rice, tobacco, maize, sorghum, wheat, barley and other organisms, showing its enormous advantage in gene editing field. Especially, the newly developed CRISPR-Cas9 system arose more attention because of its low cost, high effectiveness, simplicity and easiness. We reviewed the principles and the latest research progress of these three technologies, as well as prospect of future research and applications.
Animals ; CRISPR-Cas Systems ; DNA Breaks, Double-Stranded ; Endonucleases ; Genetic Engineering ; methods ; Humans ; Mutagenesis, Insertional ; Mutagenesis, Site-Directed ; Plants ; Zinc Fingers

Objective To investigate the correlation between MR imaging and pathological features of nucleus pulposus degeneration in the lumbar disc, and to provide a reliable evidence to evaluate the nucleus pulposus degeneration by MR imaging relative signal intensity. Methods From January 2001 to December 2001, 91 patients who underwent operative treatment for lumbar disc diseases were recruited for the study, while 4 lumbar fracture patients with no previous low back pain and 2 fresh brain-injury cadavers were recruited for contrast study. Before operation, the relative signal intensity was measured in MRI T2WI images. All 117 specimens were dyed with HE and Alcian blue CEC. The water content was also detected. The correlation between MRI relative signal intensity and chondroitin sulfate index, water content was analyzed with SPSS 10.0 software, the correlation between chondroitin sulfate index and water content was analyzed as well. Results There was significant difference between the above mentioned two groups when MRI relative signal intensity, chondroitin sulfate index and water content was compared. Whereas there was no significant statistical difference when keratin sulfate index was compared between the two groups. MRI relative signal intensity positively correlated with water content and chondroitin sulfate index, and the chondroitin sulfate index positively correlated with water content. Conclusion The MRI relative signal intensity reflects not only the water content, but also the pathological characteristics of nucleus pulposus degeneration. The quantitative classification of relative signal intensity in MRI is a method to identify the grades of nucleus pulposus degeneration.

Objective To investigate the safe directions of screw trajectory in atlas via posterior arch and lateral mass and its clinical significance. Methods Lateral radiographs and CT axial scans of atlases were performed in 30 cases with normal morphology of atlases and axes. The minimal height of posterior arch, the maximum inclination of screw projection relative to sagittal plane, and the maximum medial angle of screw projection relative to axial plane were evaluated radiologically. According to the safe directions obtained radiologically 21 cases of atlantoaxial instability were treated with screw fixation atlas via posterior arch and lateral mass. During operation the influence of screws on surrounding structures was investigated and postoperative neural symptoms were documented also. Preoperative and postoperative radiographs and CT scans of 13 patients were available and some related parameters were measured to evaluate the safety of the screw placements. Results 1) The maximum angle of screw projection to sagittal plane is about 10? cephalad to 6? caudal, with the tendency of increasing maximum angle as the minimal height of posterior arch increases. 2) When the entry point on the posterior arch was switched laterally, the medial angle of screw projection should be adjusted from 0? to 30?, correspondingly. 3) The actual directions of screw trajectory might differ from preoperative ones, but all were in the estimation range. 4) All screws were placed successfully, and the postoperative radiographs and CT scans shows no neural or vascular complications relative to atlantal screws placed in traditional way. Conclusion There is a safe range to insert atlas screw via posterior arch and lateral mass both in sagittal and axial plane.

Objective To demonstrate the histopathological changes of sequestration-type herniated disc, and investigate the related factors of its absorption. Methods 39 tissue samples were surgically removed from 37 patients with sequestration-type lumbar disc herniation. All the tissues were performed with HE stain and immunohistochemical study. In HE stain, the origin of tissue was identified; in immunohistochemical study, anti-CD34 antibody was used for detecting the vascular endothelial cells, and anti-CD68 for macrophages. The sequestration-type lumbar disc was divided into 3 groups according to the content of nucleus pulposus: nucleus pulposus group, nucleus pulposus contained group and non-nucleus pulposus group. The correlation between the extent of angiogenesis and macrophage infiltration and the factor of age, disease duration, origin of sequestrated tissue and imaging features was studied. Results 62% (24/39) of the sequestrated tissues were mainly originated from nucleus pulposus. Granulation tissue with many macrophages around new blood vessels was found in 92%(36/39) of the sequestrated tissues. There was a significant difference of the extent of angiogenesis and macrophage infiltration among these 3 groups in terms of the content of nucleus pulposus group(F=5.663, P=0.008; F=3.604, P=0.038). There was no significant correlation between the extent of angiogenesis and macrophage infiltration and age or disease duration, whereas, a positive significant correlation was found for the size of sequestrated tissue (r=0.342, P=0.033; r=0.440, P=0.005). Furthermore, the extent of angiogenesis and macrophage infiltration was significant when the relative signal intensity of sequestrated tissue on MRI was in 0.30-0.72. Conclusion The origin of sequestration-type herniated disc is mainly from nucleus pulposus, and most of the sequestration tissue can be absorbed in different extent. The extent of spontaneous absorption was mainly depended on the origin of the sequestration tissue, but not the age or disease duration. Predominant absorption is found in bigger size of the sequestration tissue and their relative signal intensity on MRI being 0.30-0.72.