[Potential geographical distribution and changes of Artemisia ordosica in China under future climate change]. / 未来气候变化下黑沙蒿在中国的潜在地理分布及变迁.

Artemisia ordosica is a forerunner species of wind-break and sand-fixation in desert steppe in China, which plays an important role in ecosystem restoration and reconstruction. How-ever, it could influence human health. Based on 89 valid data of current distribution of A. ordosica in China and 19 typical climatic factors, the MaxEnt model was used to simulate the potential distribution of A. ordosica in China under current and two scenarios (RCP 4.5 and RCP 8.5; 2050s and 2070s). The SDM toolbox of ArcGIS software was used to analyze the potential distribution range of A. ordosica and its changes in China. The importance of key climatic factors was evaluated by comprehensive contribution rate, Jackknife method, and response curve of environmental variables. The accuracy of model was tested and evaluated by area under the curve (AUC) of the test subject working characteristic (ROC). The results showed that the MaxEnt model worked well (AUC=0.980). which predicted that A. ordosica was mainly concentrated in and around Mu Us Sandy Land, consistent with the current actual distribution range. The distribution area of A. ordosica of potential high fitness under the future two scenarios decreased by 5.2%-26.8%, which was negatively affected by future climate change. Seasonal variation of temperature, mean precipitation in the coldest season, and mean annual temperature had the greatest impact. The core area of future potential distribution of A. ordosica in China was located in Mu Us Sandy Land, with a tendency for spreading to northeast (Jilin, Heilongjiang, Liaoning and some parts of Hebei).

Ginsenoside Rd Inhibits Glioblastoma Cell Proliferation by Up-Regulating the Expression of miR-144-5p.

miR-144-5p exhibits anti-tumor activities in various cancers. Although treatment for glioblastoma has progressed rapidly, novel targets for glioblastoma are insufficient, particularly those used in precision medicine. In the current study, we found that ginsenoside Rd reduced the proliferation and migration of glioblastoma cells. Ginsenoside Rd up-regulated the tumor-suppressive miR-144-5p in glioblastoma cells. Moreover, Toll-like receptor 2, which is a target of miR-144-5p, was down-regulated. After inhibition of miR-144-5p, the effect of Ginsenoside Rd on proliferation inhibition and down-regulation of Toll-like receptor 2 was reduced. These data demonstrated the ginsenoside Rd/miR-144-5p/Toll-like receptor 2 regulatory nexus that controls the glioblastoma pathogenesis of glioblastoma. Our work provided novel targets for glioblastoma diagnosis and treatment.

Gene expression analysis of primary gingival cancer by whole exome sequencing in thirteen Chinese patients.

OBJECTIVES: Early diagnosis of and markers for gingival oral squamous cell carcinoma (OSCC) is important for effective treatment. METHODS: The current study performed a whole exome sequencing of gingival OSCC tissues in thirteen Chinese patients to explore exonic mutants. RESULTS: Eighty-five genes emerged as mutants in patients with primary gingival OSCC. CCL4L1 presented a G>A transversion at chr17 17q12, position 36212480, exon 3. KDM5B presented a T>TA insertion at chr1 1q32.1, position 202766506, exon 6. ANKRD36C presented a C>G transition at chr2 2q11.1, position 95945175, exon 18. CONCLUSION: These three mutants might be new markers of gingival OSCC. The finding may provide new targets to diagnose and treat gingival OSCC.

Expression of miR-1304 in patients with esophageal carcinoma and risk factors for recurrence.

BACKGROUND: Esophageal carcinoma is a malignant gastrointestinal tumor with a very poor prognosis. MicroRNA (miR)-1304 is a newly discovered non-coding RNA, which shows differential expression in other cancers, and its clinical value in esophageal carcinoma remains unclear. AIM: To explore the expression of miR-1304 in patients with esophageal carcinoma and its clinical value. METHODS: The expression of miR-1304 in patients with esophageal carcinoma was analyzed based on the data on miR in esophageal carcinoma downloaded from The Cancer Genome Atlas database. Quantitative real-time polymerase chain reaction was adopted to determine the expression of miR-1304 in the tissues and serum of patients. The clinical diagnostic value of miR-1304 and independent factors for recurrence and prognosis of esophageal carcinoma were then analyzed. The potential target genes of miR-1304 were predicted, and then analyzed based on gene ontology, Kyoto Encyclopedia of Genes, and Genomes, and protein-protein interaction. RESULTS: The expression of miR-1304 in the tissues and serum of patients with esophageal carcinoma increased, and was also increased according to the database. Patients with high expression of miR-1304 suffered increased rates of tumor ≥ 3 cm, low differentiation and stage II + III. miR-1304 had a diagnostic value in identifying esophageal carcinoma, tumor size, differentiation and TNM stage. Tumor size, differentiation, TNM stage, and miR-1304 were independent risk factors for recurrence of esophageal carcinoma, and they had certain predictive and diagnostic value for the recurrence of esophageal carcinoma. Seventy-eight patients showed a 3-year survival rate of 38.46%, and patients with high expression of miR-1304 had a relatively lower survival rate. Multivariate analysis revealed that tumor size, differentiation, recurrence and miR-1304 were independent factors for the prognosis of patients. MiRTarBase, miRDB, and Targetscan predicted 20 target genes in total. Gene ontology enrichment analysis found 18 functions with a P < 0.05, and Kyoto Encyclopedia of Genes, and Genomes analysis found 11 signal pathways with a P < 0.05. String analysis of protein co-expression found 269 relationship pairs, of which co-expression with epidermal growth factor was the most common. CONCLUSION: miR-1304 can be used as a potential indicator for the diagnosis and recurrence of esophageal carcinoma and for survival of patients with this disease.

RP11-874J12.4 promotes oral squamous cell carcinoma tumorigenesis via the miR-19a-5p/EBF1 axis.

BACKGROUND: Oral squamous cell carcinoma (OSCC) ranks as the fifth most frequent cancer worldwide, and the recurrence and migration of OSCC still pose large threats to patients. Long non-coding RNAs (lncRNAs) have recently emerged as crucial players in cancer development, and it is of great significance to understand the regulatory nexus of lncRNAs in OSCC. METHODS: Here, we identified a novel lncRNA, RP11-874J12.4, which is ectopically expressed in OSCC and facilitates OSCC. RESULTS: RP11-874J12.4 directly binds to and regulates miR-19a-5p. Interestingly, RP11-874J12.4 and miR-19a-5p form a negative regulatory loop that inhibits the expression of miR-19a-5p in OSCC. The expression of an oncogenic transcription factor, EBF1, is unleashed in OSCC due to the low expression of miR-19a-5p, which promotes the growth and migration of OSCC. CONCLUSION: Our data illustrate a regulatory axis of RP11-874J12.4/miR-19a-5P/EBF1 and an inhibitory loop with RP11-874J12.4 and miR-19a-5p. These data provide insights into the tumorigenesis of OSCC and the novel drug targets for OSCC.

Controllable growth of three-dimensional CdS nanoparticles on TiO2 nanotubes to enhance photocatalytic activity.

Exploiting photocatalysts with characteristics of low cost, high reactivity and good recyclability is a great significance for environmental remediation and energy conversion. Herein, hollow TiO2 nanotubes were fabricated by a novel and efficient method via electrospinning and an impregnation calcination method. With the hydrothermal method, the CdS nanoparticles were modified on the surface and in walls of the TiO2 nanotubes. By changing the reaction conditions, the morphology of CdS nanoparticles presents a controllable three-dimensional (3D) structure. The morphology of the samples was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The structure and components of samples were characterized by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX) and X-ray photoelectron spectroscopy (XPS). The light absorption efficiency was detected using UV-vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL). The photocatalytic properties were evaluated by degradation of methyl orange (MO) and photocatalytic hydrogen evolution under visible light irradiation. From the results, the TiO2/CdS nanotubes exhibit better photocatalytic activity than the pure TiO2. The synthetic mechanism of TiO2/CdS heterostructures and a possible photocatalytic mechanism based on the experimental results were proposed.

Comprehensive multi-omics analysis identified core molecular processes in esophageal cancer and revealed GNGT2 as a potential prognostic marker.

BACKGROUND: Esophageal cancer is one of the most poorly diagnosed and fatal cancers in the world. Although a series of studies on esophageal cancer have been reported, the molecular pathogenesis of the disease remains elusive. AIM: To investigate comprehensively the molecular process of esophageal cancer. METHODS: Differential expression analysis was performed to identify differentially expressed genes (DEGs) in different stages of esophageal cancer from The Cancer Genome Atlas data. Exacting gene interaction modules were generated, and hub genes in the module interaction network were found. Further, through survival analysis, methylation analysis, pivot analysis, and enrichment analysis, some important molecules and related functions/pathways were identified to elucidate potential mechanisms in esophageal cancer. RESULTS: A total of 7457 DEGs and 14 gene interaction modules were identified. These module genes were significantly involved in the positive regulation of protein transport, gastric acid secretion, insulin-like growth factor receptor binding, and other biological processes as well as p53 signaling pathway, epidermal growth factor signaling pathway, and epidermal growth factor receptor signaling pathway. Transcription factors (including hypoxia inducible factor 1A) and non-coding RNAs (including colorectal differentially expressed and hsa-miR-330-3p) that significantly regulate dysfunction modules were identified. Survival analysis showed that G protein subunit gamma transducin 2 (GNGT2) was closely related to survival of esophageal cancer. DEGs with strong methylation regulation ability were identified, including SST and SH3GL2. Furthermore, the expression of GNGT2 was evaluated by quantitative real time polymerase chain reaction, and the results showed that GNGT2 expression was significantly upregulated in esophageal cancer patient samples and cell lines. Moreover, cell counting kit-8 assay revealed that GNGT2 could promote the proliferation of esophageal cancer cell lines. CONCLUSION: This study not only revealed the potential regulatory factors involved in the development of esophageal cancer but also deepens our understanding of its underlying mechanism.

Curcumin upregulates S100 expression and improves regeneration of the sciatic nerve following its complete amputation in mice.

The repair of peripheral nerve injury after complete amputation is difficult, and even with anastomosis, the rapid recovery of nerve function remains challenging. Curcumin, extracted from plants of the genus Curcuma, has been shown to have anti-oxidant and anti-inflammatory properties and to improve sciatic nerve crush injury in rats. Here, we determined whether curcumin had neuroprotective effects following complete peripheral nerve amputation injury. BALB/c mice underwent complete sciatic nerve amputation, followed by an immediate epineurium anastomosis. Mice were intragastrically administered curcumin at doses of 40 (high), 20 (moderate), and 10 mg/kg/d (low) for 1 week. We found that myelin in the mice of the high- and moderate-dose curcumin groups appeared with regular shape, uniform thickness, clear boundary, and little hyperplasia surrounding the myelin. High and moderate doses of curcumin markedly improved both action potential amplitude of the sciatic nerves and the conduction velocity of the corresponding motor neurons, and upregulated mRNA and protein expression of S100, a marker for Schwann cell proliferation, in L4-6 spinal cord segments. These results suggest that curcumin is effective in promoting the repair of complete sciatic nerve amputation injury and that the underlying mechanism may be associated with upregulation of S100 expression.

Knockdown of Nogo gene by short hairpin RNA interference promotes functional recovery of spinal cord injury in a rat model.

The specific myelin component Nogo protein is one of the major inhibitory molecules of spinal cord axonal outgrowth following spinal cord injury. The present study aimed to investigate the effects of silencing Nogo protein with shRNA interference on the promotion of functional recovery in a rat model with spinal cord hemisection. Nogo-A short hairpin RNAs (Nogo shRNAs) were constructed and transfected into rats with spinal cord hemisection by adenovirus-mediated transfection. Reverse transcription­polymerase chain reaction and western blotting were performed to analyze the expression of Nogo-A and Growth Associated Protein 43 (GAP-43). In addition, Basso Beattie Bresnahan (BBB) scores were used to assess the functional recovery of rats following spinal cord injury. The results demonstrated that expression of the Nogo­A gene was observed to be downregulated following transfection and GAP­43 expression was observed to increase. The BBB scores were increased following treatment with Nogo shRNAs, indicating functional recovery of the injured nerves. Thus, Nogo-A shRNA interference can knockdown Nogo gene expression and upregulate GAP-43 to promote the functional recovery of spinal cord injury in rats. This finding may advance progress toward assisting the regeneration of injured neurons through the use of Nogo-A shRNA.

Bone morphogenetic protein-2 sustained delivery by hydrogels with microspheres repairs rabbit mandibular defects.

Mandible defect is a difficult issue in dental surgery owing to limited therapeutic options. Recombinant human bone morphogenetic protein-2 (rhBMP2) is osteoinductive in bone regeneration. This article prepared chitosan/collagen hydrogels with rhBMP2-incorporated gelatin microsphere (GMs) for a sustained release of rhBMP2 to induce bone regeneration in rabbits. In experiments, mandibular defects of 8 mm in diameter and 3 mm in depth were surgically prepared on the right cheek of 27 rabbits. Either chitosan/collagen hydrogels alone, rhBMP2-incorporated hydrogels, or hydrogels with rhBMP2-incorporated GMs were implanted to the defect sites. The animals were euthanized at 2, 6, 12 weeks following surgery. In results, scanning electronic microscope images revealled spherical GMs. The complex delivery systems, hydrogels with rhBMP2-incorporated GMs, exhibited ideal release profiles in vitro. The complex delivery systems resulted in apparent new bone formation within 12 weeks, as evidenced by computed tomography and histological observations. All these results demonstrated that the chitosan/collagen hydrogels with rhBMP2-incorporated GMs had a better capacity to heal mandible defects than other two hydrogel scaffolds. Chitosan/collagen hydrogels with rhBMP2-incorporated GMs might be potential carriers of rhBMP2 for accelerating the repair of mandibular defects.

Study of bone-screw surface fixation in lumbar dynamic stabilization.

BACKGROUND: We aimed to use the animal model of dynamic fixation to examine the interaction of the pedicle screw surface with surrounding bone, and determine whether pedicle screws achieve good mechanical stability in the vertebrae. METHODS: Twenty-four goats aged 2-3 years had Cosmic ® pedicle screws implanted into both sides of the L2-L5 pedicles. Twelve goats in the bilateral dynamic fixation group had fixation rods implanted in L2-L3 and L4-L5. Twelve goats in the unilateral dynamic fixation group had fixation rods randomly fixed on one side of the lumbar spine. The side that was not implanted with fixation rods was used as a static control group. RESULTS: In the static control group, new bone was formed around the pedicle screw and on the screw surface. In the unilateral and bilateral dynamic fixation groups, large amounts of connective tissue formed between and around the screw threads, with no new bone formation on the screw surface; the pedicle screws were loose after the fixed rods were removed. The bone mineral density and morphological parameters of the region of interest (ROI) in the unilateral and bilateral dynamic fixation group were not significantly different (P > 0.05), but were lower in the fixed groups than the static control group (P < 0.05). This showed the description bone of the ROI in the static control group was greater than in the fixation groups. Under loading conditions, the pedicle screw maximum pull force was not significantly different between the bilateral and unilateral dynamic fixation groups (P > 0.05); however the maximum pull force of the fixation groups was significantly less than the static control group (P < 0.01). CONCLUSIONS: Fibrous connective tissue formed at the bone-screw interface under unilateral and bilateral pedicle dynamic fixation, and the pedicle screws lost mechanical stability in the vertebrae.

Extracellular matrix-coating pedicle screws conduct and induce osteogenesis.

BACKGROUND: The purpose of the present study was to study the effects of the extracellular matrix-coating pedicle screws on the conduction and induction of bone formation in young sheep. METHODS: Pedicle screws [coated with collagen/chondroitin sulfate (coll/CS), hydroxyapatite (HA), and coll/CS/HA or uncoated] were randomly implanted into the L2-L5 pedicles of sheep. In the first stage, a static experiment was performed. In the second stage, a loading test was performed by implanting connecting rods. After 3 months, the lumbar vertebrae with the screws were removed and examined by micro-CT, histological, and biomechanical analyses. RESULTS: Under non-loading conditions, there is bone formation around the surfaces of coated screws. Bone formation on the surface of the coll/CS/HA coating of pedicle screws was the highest. In terms of the trabecular bone morphology parameters of the region of interest around the surface of the pedicle screws, those associated with coll/CS/HA coatings were highest under non-loading conditions, the pullout strength of the coll-/CS-/HA-coated screws was the highest and that of the uncoated screws was minimal. Under loading conditions, the maximum pullout strength of each group of pedicle screws was less than that of the pedicle screws in the non-loading state. CONCLUSIONS: Under non-loading conditions, the organic and inorganic components of the titanium pedicle screw coatings can conduct or induce bone formation around the surface of the screws. The ability of the coll/CS/HA coating to induce bone formation was the strongest. Under loading conditions, a large amount of connective tissue formed around the surface of the screws in each group.

Comparison of one-level microendoscopy laminoforaminotomy and cervical arthroplasty in cervical spondylotic radiculopathy: a minimum 2-year follow-up study.

BACKGROUND: This study aims to compare the perioperative parameters and clinical results between microendoscopy laminoforaminotomy (MELF) and cervical arthroplasty (CA) in the treatment of one-level cervical spondylotic radiculopathy in a retrospective study. METHODS: From 2003 to 2007, a total of 97 patients with one-level cervical spondylotic radiculopathy were treated. Forty-five patients underwent CA. Fifty-two patients underwent MELF. Patient demographics and operative data were collected with a minimum 2-year follow-up. Perioperative parameters were compared. Clinical assessment in terms of neck disability index (NDI), short form (SF)-36, and visual analogue scale (VAS) of arm pain and neck pain was performed prior to surgery and at 1.5, 3, 6, 12, and 24 months after surgery. RESULTS: Fluoroscopy time (CA, 60.3 s; MELF, 12.1 s; P < 0.01) and surgical time (CA, 95.1 min; MELF, 24.0 min; P < 0.01) were significantly longer in the CA cases. Shorter hospitalized days (CA, 1.1 days; MELF, 0.13 days; P < 0.01) and less estimated blood loss (EBL; CA, 75.8 ml; MELF, 31.9 ml; P < 0.01) were observed in the MELF group. Both CA and MELF groups showed significant improvement in NDI, VAS of neck pain and arm pain, and SF-36 (P < 0.05 for each) at 1.5, 3, 6, 12, and 24 months after surgery, but there was no significant difference between them (P > 0.05). CONCLUSIONS: As alternatives of anterior cervical decompression and fusion (ACDF), both CA and MELF can produce satisfactory clinical outcomes. MELF has the additional benefits of less blood loss, less surgical time, less X-ray time, and shorter hospital stay.

Age-related differences in the biological parameters of vertebral cancellous bone from Chinese women.

BACKGROUND: With aging, the human fracture risks gradually increase. This is mainly due to the corresponding changes of the biomechanical parameters of human bone presents with aging. We measured the microstructural parameters of lumbar bone from women in several age groups by micro-computed tomography and scanning electron microscopy. We observed changes in lumbar cancellous bone mineral density and in biomechanical parameters with aging to elucidate the relationship between age and risk of fracture. We provide theoretical support for human pathology, fracture risk increased with age and the individualized of each age group. METHODS: Thirty-two fresh L3 vertebral bodies were donated from 32 women, aged 20-59 years and were divided into four age groups: 20 to 29 years (group A); 30 to 39 years (group B); 40 to 49 years (group C); and 50 to 59 years (group D). Conventional lumbar separation was performed by removing soft tissue and subsidiary structures, leaving only the vertebral body. The vertebral body was cut into halves along the median sagittal plane, maintaining the upper and lower end-plates of each half, and used for biomechanical, morphological, and density measurements. RESULTS: Comparing group A to B, the rod-like trabecular thickness (Tb.Th) decreased; the trabecular spacing (Tb.Sp) increased; the plate-like Tb.Th decreased; bone mineral density, tissue mineral density, bone volume fraction, and bone surface fraction decreased, and the elastic modulus and the ultimate stress decreased (all changes P < 0.05). Similar significant (P < 0.05) trends were obtained when comparing group C to D. With aging, the collagen cross-linking capacity declined, the thickness of the collagen fibrils was variable (ranging from almost the same to loose, sparse, or disordered), and the finer collagen fibrils between the thick filaments were disorganized. CONCLUSIONS: In women aged 20 to 59 years, the rod-like and plate-like Tb.Th of the vertebral body decreased, while Tb.Sp increased. Additionally, the density, elastic modulus, and ultimate stress of the cancellous bone decreased with age. These associated changes in bone microstructure, density, and biomechanics with age may lead to an increasing risk of osteoporosis and fracture.

Inhibition of Nogo expression to promote repair after spinal cord injury.

BACKGROUND: One of the reasons for poor neuroregeneration after central nervous system injury is the presence of inhibitory factors such as Nogo. Here, we tested the inhibition of Nogo by RNA interference both in vitro and in vivo, using recombinant adenovirus-mediated transfection of short hairpin RNAs, to explore a new method of treatment for spinal cord injury. METHODS: We designed and cloned two Nogo-specific short hairpin RNAs and an unrelated short hairpin RNA, packaged the clones into adenovirus, and amplified the recombinant virus in 293 cells. We then tested the inhibition of Nogo expression both in vitro in adenovirus-transfected oligodendrocytes and in vivo in spinal cord tissue from adenovirus-transfected spinal cord injury model rats. We tested Nogo expression at the mRNA level by reverse-transcription PCR and at the protein level by Western blotting and immunohistochemistry. RESULTS: In vitro, the two specific Nogo short hairpin RNAs decreased Nogo mRNA expression by 51% and 49%, respectively, compared with Nogo expression in cells transfected with the unrelated control small hairpin RNA (P < 0.005). Similarly, Nogo protein expression decreased by 50% and 48%, respectively (P < 0.005). In vivo, in spinal cord injury model rats, the two specific Nogo short hairpin RNAs decreased Nogo mRNA expression by 45% and 40%, respectively, compared with Nogo expression in spinal cord injury model rats transfected with the unrelated control short hairpin RNA (P < 0.005). The Nogo protein level was similarly decreased. CONCLUSIONS: We were successful in specifically downregulating Nogo at the mRNA and protein levels by adenovirus-mediated delivery of short hairpin RNAs, both in vitro and in vivo. This confirms the effectiveness of RNA interference for the inhibition of Nogo gene expression and the efficiency of using adenovirus for delivery. Thus gene therapy may be an effective treatment for spinal cord injury.

Age-related differences in microstructure, density and biomechanics of vertebral cancellous bone of Chinese males.

The conventional lumbar separation was performed by removing soft tissue, subsidiary structures and leaving only the vertebral body. The vertebral body was cut into two halves along the median sagittal plane, keeping the upper and lower end plates of each half, which were subsequently used for biomechanical, morphological and density experiments. From the age of 20-29 to 30-39 years, both the horizontal trabecular thickness (Tb.Th) and vertical Tb.Th decreased; the horizontal and vertical Tb.Sp increased; the plate-like trabecular Tb.Th decreased; the apparent density and volume ratio decreased; and the elastic modulus and the ultimate stress decreased; with all changes being statistically significant (p < 0.01). Similar trends were obtained from ages 40-49 to 50-59, although the changes were not significant (p > 0.05), except for the reduction in ultimate stress (p < 0.05). With aging, the collagen cross-linking capacity declined; the thicknesses of the collagen fibrils were variable, ranging from almost the same to loose, sparse or disordered thickness; and the finer collagen fibrils between the thick filaments were disorganized. In males aged from 20 to 59 years old, the horizontal and vertical Tb.Th and the plate-like Tb.Th of the vertebral body decreased, while the horizontal and vertical Tb.Sp increased. Additionally, the density, elastic modulus and the ultimate stress of the cancellous bone decreased with age. Thus, the associated changes of bone microstructure, density and biomechanics with age may lead to an increased risk of osteoporosis and fracture.

In vivo study of extracellular matrix coating enhancing fixation of the pedicle screw-bone's interface.

BACKGROUND: Based on in vivo research on the effect of the coating of the extracellular matrix composition of pedicle screws on the conduction and induction of bone formation in young sheep, the aim of this study was to investigate the application of coated pedicle screws in sheep with scoliosis whose spines are under constant development. METHODS: Four groups of pedicle screws were randomly implanted into bilateral L2-L5 pedicles of 2.5- to 3-month-old sheep. A static experiment was performed on one side and a loading test was performed on the other side by implanting connecting rods at the L2-L3 and L4-L5 segments. The changes in the force on the coated screws and the combination of the surface of the coated screws with the surrounding bone in the growth process of young sheep's spines with aging were observed. After 3 months, the lumbar vertebrae with the screws were removed and examined by micro-CT, histological, and biomechanical analyses. RESULTS: Under nonloading conditions, there is bone formation around the surfaces of coated screws. The bone forming on the surface of collagen/chondroitin sulfate/hydroxyapatite coating of pedicle screws is the most, the one of the collagen/chondroitin sulfate coating and hydroxyapatite coating is followed, and no significant difference between the two groups. In terms of the trabecular bone morphology parameters of the region of interest around the surface of the pedicle screws, such as bone mineral content, bone mineral density, tissue mineral content, tissue bone mineral density, bone volume fraction, and connection density, those associated with collagen/chondroitin sulfate/hydroxyapatite coatings are largest and those unassociated with coatings are smallest. Under nonloading conditions, the pullout strength of the collagen/chondroitin sulfate/hydroxyapatite-coated screws was largest, and that of the uncoated screws was minimal (P < 0.01). Under loading conditions, the maximum pullout strength of each group of pedicle screws was less than that of the pedicle screws in the nonloading state (P < 0.01) with no significant difference between the groups (P > 0.05). CONCLUSIONS: Under nonloading conditions, the coatings of both organic and inorganic components of the extracellular matrix of titanium pedicle screws can conduct or induce bone formation around the surface of the screws. The ability of collagen/chondroitin sulfate/hydroxyapatite coatings to induce bone formation is stronger; under loading conditions, a large amount of connective tissue formed around the surfaces of the screws in each group. No significant differences were found between the groups.

Feasibility of vertebral internal fixation using deer and sheep as animal models.

BACKGROUND: Studies on new vertebral internal fixations of animals are very important prior to clinical application. This study aimed to determine the feasibility of vertebral internal fixation on morphologic and biomechanical properties using deer and sheep as animal models and comparing to human data. METHODS: Thirty sets of fresh Sika deer lumbar, 30 sets of fresh sheep lumbar, and 20 sets of fresh lumbar from male cadavers were used. We examined the morphology of the centra and pedicles of the three groups, and determined the cancellous bone density and biomechanical properties in all groups. RESULTS: There were marked differences in all parameters measured between the different species. The sizes of the upper, middle, and lower transverse diameter were largest in the human, followed by the deer, then the sheep. The index of centrum transverse diameters and sagittal diameters were less than 0.8 (a triangle), and the deer was more similar to the human. The heights of the right vertebral pedicles and the anterior disc heights (IDH) were largest in the human, followed by the deer, then the sheep. The apparent density, elastic modulus, and ultimate load were largest in the sheep, followed by the deer, then the human. The range of motion (ROM) of functional lumbar units (FLUs) with a combined flexion-extension moment was largest in the human, followed by the deer then the sheep. CONCLUSIONS: The deer lumbar is more similar to that of human in anatomical form and biomechanics than the sheep lumbar. As such, deer is more appropriate as an animal model for use in vertebral internal fixation studies.