Halomonas profundi sp. nov., isolated from deep-sea sediment of the Mariana Trench.

Two novel Gram-stain-negative, facultative anaerobic, non-flagellated, rod-shaped bacterial strains, designated MT13T and MT32, were isolated from sediment samples collected from the Mariana Trench at a depth of 8300 m. The two strains grew at -2-30 °C (optimum, 25 °C), at pH 5.5-10.0 (optimum, pH 7.5-8.0) and with 0-15 % (w/v) NaCl (optimum, 3-6 %). They did not reduce nitrate to nitrite nor hydrolyse Tweens 40 and 80, aesculin, casein, starch and DNA. The genomic G+C contents of draft genomes of strain MT13T and MT32 were 52.2 and 54.1 m ol%, respectively. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strains MT13T and MT32 were affiliated with the genus Halomonas, with the highest similarity to the type strain of Halomonas olivaria. The values of average nucleotide identity and in silico DNA-DNA hybridization between strain MT13T and MT32, and between strain MT13T and five closely related type strains of Halomonas species indicated that strains MT13T and MT32 belonged to the same species, but represented a novel species in the genus of Halomonas. The major cellular fatty acids of strains MT13T and MT32 were C16 : 0, summed feature 3(C16 : 1 ω7c/ω6c) and summed feature 8 (C18 : 1 ω7c/ω6c). Major polar lipids of strains MT13T and MT32 included phosphatidylglycerol, phosphatidylethanolamine and diphosphatidylglycerol. Ubiquinone-9 was the predominant respiratory quinone. Based on data from the present polyphasic study, strains MT13T and MT32 represent a novel species of the genus Halomonas, for which the name Halomonas profundi sp. nov. is proposed. The type strain is MT13T (=MCCC 1K06389T=KCTC 82923T).

Timing of surgical decompression for traumatic cervical spinal cord injury.

PURPOSE: Although there have been numerous studies aimed at determining the effects and safety of early vs. late surgical decompression for traumatic cervical spinal cord injury, controversies still exist regarding the optimal timing of surgery for this serious spinal trauma. This study was conducted to evaluate the effectiveness and safety of early vs. late surgical decompression for lower cervical spine trauma associated with spinal cord injury. METHODS: A retrospective review of was performed on consecutive patients who underwent surgical decompression for lower cervical (C3-C7) spine trauma associated with spinal cord injury at six institutions across China from January 2007 to January 2012. These patients were analysed according to the timing of surgical intervention. The early group comprised patients who underwent surgery within the first 72 hours after being injured, whilst the late group comprised patients who underwent surgery after the first 72 hours. For analysis of neurologic improvement, patients who had completed a follow-up of at least six months were assessed. Other outcomes analysed were hospitalisation periods, complications and mortality. RESULTS: A total of 595 patients were identified (456 men and 139 women at an average age of 41.4 years), with 212 in the early group and 383 in the late group. Patients in both groups had made a significant neurologic improvement in the final follow-up, but no statistically significant difference was noted between groups. Patients in the early group had a significantly shorter hospital stay (15.4 vs. 18.3 days, p <0.001) but realised no benefits in terms of intensive care unit length of stay and ventilator days. No significant differences were identified between groups with regards complications (pneumonia, pulmonary embolism, wound infection, sepsis and urinary tract infection). Compared with the late group, the early group had a significantly higher incidence of postoperative neurological deterioration (6.6 vs. 0.7 %, p <0.001) and mortality (7.1 vs. 2.1 %, p = 0.003). CONCLUSION: The timing of surgery for patients sustaining traumatic lower cervical spine injury with neurological involvement did not affect neurological recovery. Early surgical intervention was associated with a higher incidence of mortality and neurological deterioration compared with late surgical intervention, indicating that surgery after the first 72 hours might be relatively safe.

Early clinical effects of the Dynesys system plus transfacet decompression through the Wiltse approach for the treatment of lumbar degenerative diseases.

BACKGROUND: This study investigated early clinical effects of Dynesys system plus transfacet decompression through the Wiltse approach in treating lumbar degenerative diseases. MATERIAL AND METHODS: 37 patients with lumbar degenerative disease were treated with the Dynesys system plus transfacet decompression through the Wiltse approach. RESULTS: Results showed that all patients healed from surgery without severe complications. The average follow-up time was 20 months (9-36 months). Visual Analogue Scale and Oswestry Disability Index scores decreased significantly after surgery and at the final follow-up. There was a significant difference in the height of the intervertebral space and intervertebral range of motion (ROM) at the stabilized segment, but no significant changes were seen at the adjacent segments. X-ray scans showed no instability, internal fixation loosening, breakage, or distortion in the follow-up. CONCLUSIONS: The Dynesys system plus transfacet decompression through the Wiltse approach is a therapeutic option for mild lumbar degenerative disease. This method can retain the structure of the lumbar posterior complex and the motion of the fixed segment, reduce the incidence of low back pain, and decompress the nerve root.

Phytoplankton-derived polysaccharides and microbial peptidoglycans are key nutrients for deep-sea microbes in the Mariana Trench.

BACKGROUND: The deep sea represents the largest marine ecosystem, driving global-scale biogeochemical cycles. Microorganisms are the most abundant biological entities and play a vital role in the cycling of organic matter in such ecosystems. The primary food source for abyssal biota is the sedimentation of particulate organic polymers. However, our knowledge of the specific biopolymers available to deep-sea microbes remains largely incomplete. One crucial rate-limiting step in organic matter cycling is the depolymerization of particulate organic polymers facilitated by extracellular enzymes (EEs). Therefore, the investigation of active EEs and the microbes responsible for their production is a top priority to better understand the key nutrient sources for deep-sea microbes. RESULTS: In this study, we conducted analyses of extracellular enzymatic activities (EEAs), metagenomics, and metatranscriptomics from seawater samples of 50-9305 m from the Mariana Trench. While a diverse array of microbial groups was identified throughout the water column, only a few exhibited high levels of transcriptional activities. Notably, microbial populations actively transcribing EE genes involved in biopolymer processing in the abyssopelagic (4700 m) and hadopelagic zones (9305 m) were primarily associated with the class Actinobacteria. These microbes actively transcribed genes coding for enzymes such as cutinase, laccase, and xyloglucanase which are capable of degrading phytoplankton polysaccharides as well as GH23 peptidoglycan lyases and M23 peptidases which have the capacity to break down peptidoglycan. Consequently, corresponding enzyme activities including glycosidases, esterase, and peptidases can be detected in the deep ocean. Furthermore, cell-specific EEAs increased at 9305 m compared to 4700 m, indicating extracellular enzymes play a more significant role in nutrient cycling in the deeper regions of the Mariana Trench. CONCLUSIONS: Transcriptomic analyses have shed light on the predominant microbial population actively participating in organic matter cycling in the deep-sea environment of the Mariana Trench. The categories of active EEs suggest that the complex phytoplankton polysaccharides (e.g., cutin, lignin, and hemicellulose) and microbial peptidoglycans serve as the primary nutrient sources available to deep-sea microbes. The high cell-specific EEA observed in the hadal zone underscores the robust polymer-degrading capacities of hadal microbes even in the face of the challenging conditions they encounter in this extreme environment. These findings provide valuable new insights into the sources of nutrition, the key microbes, and the EEs crucial for biopolymer degradation in the deep seawater of the Mariana Trench. Video Abstract.

[Surgical treatment strategies of odontoid fractures].

OBJECTIVE: To explore the characteristics of both odontoid fractures and adjacent section instability so as to devise proper surgical strategies and achieve better curative effect. METHODS: A total of 37 patients (including 26 males and 11 females) with odontoid fractures treated from January 2005 to June 2012 with a mean age of (21-65) 36 years were analyzed retrospectively. Among 25 cases of simple odontoid fractures, there were type II (n = 20) and low type III (n = 5). There were 12 cases of odontoid fractures with adjacent section instability with C1/2 instability (n = 6), C2/3 instability (n = 4) and C1/2 and C2/3 instability (n = 2). The Frankel scale was used to assess nerve function. There were Grade A (n = 1), Grade B (n = 2), Grade C (n = 3) and Grade D (n = 6) at preoperation. Treatment included anterior and/or posterior pedicle screw fixation for reducing fracture and stabilizing upper cervical vertebrae. The Japanese Orthopedic Association (JOA) standards were used to evaluate the therapeutic effect. According to Frankel grade, nerve functional restoration of spinal cord injury was gauged. Fracture healing, bone graft fusion and spinal stability were monitored by radiology or computed tomography. RESULTS: All patients underwent surgery safely without severe complications. The average follow-up period was 18 (12-48) months. There was significant difference (t = 13.464, P = 0.000) in JOA score between pre-operation (12.11 ± 2.09) and post-operation (15.36 ± 3.17). And the rate of improvement was 90.8% ± 11.6% and that of "excellent" or "good" 98%. Degree 1-2 recovery of neural function was achieved in all except for 1 case of Frankel B. All patients were immobilized in a hard collar for 3 months postoperatively. Fusion occurred in all cases within a mean time of (3-6) 4.5 months. Radiology confirmed a proper screw position at postoperation. There were no occurrences of such complications as loosening, displacement or breakage of internal fixations. CONCLUSION: Proper surgical approaches may be selected according to the characteristics of both odontoid fractures and adjacent section instability.

[Short-segment fixation of thoracolumbar burst fractures using pedicle fixation at the level of fracture in patients with osteoporosis].

OBJECTIVE: To evaluate the curative effect of short-segment transpedicular fixation plus vertebra fracture fixation for thoracolumbar burst fractures in patients with osteoporosis. METHODS: The clinical data of thoracolumbar burst fractures in 46 patients with osteoporosis, single segment fracture and neurological intactness were analyzed retrospectively from January 2008 to January 2012. There were 20 males and 26 females with a mean age of 64.5 (56-78) years. The mechanisms of injury were fall (n = 20), traffic accident (n = 12), high falling injury (n = 8) and heavy pound injury (n = 4). The involved vertebrae included T11 (n = 5); T12 (n = 17); L1 (n = 21); L2 (n = 3). Pedicle screw was inserted into injured vertebra and the height of collapsed vertebra fractures reduced with position and instrument. Visual analogue scale (VAS) and short form-36 scoring systems were used to evaluate pain level and quality of life. The height restoration and kyphotic correction rates of fracture level were measured radiologically. RESULTS: All patients underwent surgery safely without severe complications. The average follow-up period was 20.5 (9-48) months. There was significant difference (t = 20.057, P = 0.000; t = 24.287, P = 0.000) in VAS score between last follow-up (3.09 ± 1.01) and post-operation (2.35 ± 1.02) versus pre-operation (7.22 ± 1.05) respectively. And also there was significant difference (P < 0.05) in SF-36 score between last follow-up (126.5 ± 22.3) and post-operation (96.7 ± 17.5). The Cobb angle was corrected to (5.6 ± 1.9)° of post-operation and (7.8 ± 3.3)° of last follow-up. The loss rate of vertebral was (4.8 ± 5.2)% of post-operation and (7.6 ± 2.9) % of last follow-up. There was no loosening or breakage of internal fixations. CONCLUSIONS: The approach of short-segment transpedicular fixation plus vertebra fracture fixation is both safe and effective to maintain reduction and reduce the rate of correction loss and instrument failure.

[Treatment of degenerative lumbar scoliosis with selective segmental transforaminal lumbar interbody fusion].

OBJECTIVE: To explore the treatment outcomes of degenerative lumbar scoliosis (DLS) with selective segmental transforaminal lumbar interbody fusion (TLIF). METHODS: The clinical data were analyzed for a total of 42 cases with degenerative scoliosis from November 2008 to March 2011.There were 14 males and 28 females with a mean age of 62.4 years (range, 41-76).The indications for TLIF of motion segment included segmental instability and significant upper endplate obliquities of L3 or L4.Interbody spinal fusion was performed for 3 segments in 3 cases; 2 in 17; 1 in 22.All patients were followed postoperatively with a mean duration of 1.6 years (range, 0.5-3).The imaging examinations included Cobb angle of scoliosis and lumbar lordosis angle.The clinical symptoms were evaluated with Oswestry disability index (ODI) score. RESULTS: The mean preoperative Cobb angle of 32.7° ± 12.4° was significantly corrected to 9.2° ± 5.5° at the final follow-up (t = 14.86, P < 0.05) with a correction rate of 71.8%. The mean preoperative lumbar lordosis angle of 25.5° ± 12.6° was also significantly corrected to 39.3° ± 8.5° (t = 12.11, P < 0.05) with a correction rate of 46.4%.There was significant difference (P < 0.05) in ODI between preoperation (43.8 ± 5.6) and postoperation (18.7 ± 1.8).But no significant difference (P > 0.05) existed in ODI between postoperation (18.7 ± 1.8) and the final follow-up (23.6 ± 2.3). And 86% of the patients showed considerable symptomatic improvement of neurogenic intermittent claudication. And clinical symptoms and functional tolerance for daily activities improved postoperatively in 92%. At the follow-up after 6 months postoperatively, all operated segments achieved fusion standard and no pseudoarthrosis formed. CONCLUSION: Selective segmental TLIF is helpful in correcting lumbar lordosis, segmental deformity and translation. And it offers better outcomes of posterior spinal fusion for the treatment of DLS.

[Selection of suitable procedure in the treatment of degenerative lumbar scoliosis based upon imaging studies].

OBJECTIVE: To compare the clinical efficacies of two different procedures in the treatment of degenerative lumbar scoliosis. METHODS: From August 2008 to August 2011, 28 patients of lumbar degenerative scoliosis were divided into one group (n = 14) undergoing modified transforaminal lumbar interbody fusion (TLIF) instrumented surgery and another group (n = 14) undergoing posterolateral fusion (PLF) instrumented surgery. There were 12 males and 16 females with a mean age of 66.2 years (range: 54-79). The operative durations and bleeding volumes of two groups were recorded. The post-operative efficacy was evaluated with VAS (visual analogue scale) for low back pain, ODI (Oswestry disability index), Cobb' angle and lumbar lordosis angle on plain film. RESULTS: The mean follow-up period was 25.9 months. The operative duration was 192.0 ± 44.7 min in modified TLIF group versus 163.0 ± 39.0 min in PLF group. The bleeding volume was 718.0 ± 197.2 ml in modified TLIF group versus 546.0 ± 226.6 ml in PLF group. All operated lumbar intervertebral achieved bony fusion in modified TLIF group by the last follow-up. Two cases had no bony fusion and there was one case of pseudarthrosis in PLF group. Significant differences existed between two groups in pre-operative and post-operative values of VAS, ODI, Cobb' s angle and lumbar lordosis angle (P < 0.05). There were significant differences between two groups in the values of pre-operative and post-operative VAS and lumbar lordosis angle (P < 0.05) but not in the values of pre-operative and post-operative ODI and Cobb' s angle (P > 0.05). CONCLUSION: As an alternative, safe and effective procedure, modified TLIF instrumented is superior to PLF instrumented in the treatment of lumbar degenerative scoliosis.

[Combination of bone marrow concentrate and PGA scaffolds enhancing bone marrow stimulation in the repair of rabbit articular cartilage].

OBJECTIVE: To observe the effects of bone marrow concentrate (BMC)-PGA scaffolds for bone marrow stimulation enhancement and repairing rabbit articular cartilage. METHODS: A rabbit model of articular cartilage defect was established for BMC-PGA stent implantation. After 8 weeks, the experimental animals were sacrificed. And the methods of hematoxylin and eosin stain, toluidine blue stain and immunohistochemistry were used to evaluate the effects of bone marrow stimulation enhancement and rabbit cartilage defect repairing. RESULTS: Visible new cartilage formation was evident after implantation. As compared with other groups, the repairing effect was better. CONCLUSION: The implantation of BMC-PGA scaffolds is both simple and effective in the repair of articular cartilage.

[Transforaminal lumbar interbody fusion in the treatment of lumbar intervertebral disc herniation with lumbar instability].

OBJECTIVE: To explore the surgical efficacy of transforaminal lumbar interbody fusion (TLIF) technique in the treatment of lumbar intervertebral disc herniation with lumbar instability. METHODS: From November 2008 to August 2011, 47 patients of lumbar intervertebral disc herniation underwent TLIF. There were 25 males and 22 females with an average age of 52 years (range: 30 - 68). The preoperative diagnoses included lumber intervertebral disc herniation plus lumbar instability (n = 16); lumbar degenerative spondylolisthesis (n = 9); lumbar spinal stenosis (n = 15) and degenerative lumbar scoliosis (n = 7). A total of 63 levels were fused, including single level (n = 31) and double levels (n = 16). Posterolateral fixation was secured with pedicle screw. Unilateral resections of inferior articular facet of superior vertebra and superior articular facet of inferior vertebra were performed to expose unilateral intervertebral vertebral foramen. Decompression of vertebral canal was expanded to the opposite side if symptoms recurred when never root was decompressed satisfactorily. Finally TLIF was performed routinely. The standard criteria of JOA (Japanese Orthopedic Association) and ODI (Oswestry disability index) were applied for efficacy evaluations. And the intervertebral height and bone fusion were observed radiologically. RESULTS: All patients underwent surgery smoothly without severe complications. The average follow-up period was 19.6 months (range: 6 - 36). Significant differences existed in JOA score between pre-operation (11.0 ± 2.8) and postoperation (15.4 ± 3.4) (P = 0.01) and ODI score between pre-operation (37.8 ± 4.6) and postoperation (18.8 ± 3.8). At 6.5 months postoperatively, all operated segments achieved fusion and there was no broken screw. There was 1 case of cage dislocation. CONCLUSION: In select patients of lumbar intervertebral disc herniation with spinal instability, TLIF may be performed easily and safely with fewer complications and total root decompression.

[Short fusion and long fusion for degenerative lumbar scoliosis with lumbar stenosis].

OBJECTIVE: To explore the indications, surgical techniques and prognostic factors of short fusion versus long fusion for elder patients with degenerative lumbar scoliosis. METHODS: Thirty-eight patients undergoing different kinds of surgical procedures for lumbar spinal scoliosis between June 2005 and October 2010 were recruited for this retrospective study. The mean patient age at surgery was 64.2 years (range: 61 - 75). The short fusion group included 13 patients and the long fusion group 25 patients. RESULTS: There were a variety of treatment methods of degenerative scoliosis based on the symptomatology and radiological measurements of scoliosis and stenosis. Thirty-eight patients were followed up for an average of 37 months. The number of fused levels was 2.8 ± 0.7 segments in the short fusion group versus 5.1 ± 1.4 in the long fusion group. The average preoperative Cobb angle was 18.6° (range: 12 - 27) in the short fusion group versus 33.5° (range: 3 - 42) in the long fusion group. The correction of Cobb angle averaged 40% in the short fusion group versus 67% in the long fusion group. Clinical symptoms and functional tolerance for daily activities improved postoperatively. Radiographic evaluations showed reduced deformity on the frontal and sagittal planes. There were no infections, pseudoarthrosis, instrument-related failures or reoperations. CONCLUSIONS: Long segment fusion is superior to its short segment counterpart in correcting scoliotic curvature and coronal imbalance and improving rotational subluxation of apical vertebra. Careful perioperative preparation is essential in the treatment of elder patients with lumbar spinal scoliosis.

[Application of C1-C2 pedicle screw fixation in atlantoaxial complex fracture].

OBJECTIVE: To explore the therapeutic effects of posterior transpedicular screw internal fixation in atlantoaxial complex fracture patients. METHODS: Among 17 patients, there were Anderson II type of odontoid plus atlas fracture (n = 10) and Hangman plus atlas fracture (n = 7). They were categorized by their preoperative spinal cord scores according to the Frankel classification: C-class (n = 2), D-class (n = 6) and E-class (n = 5). Transpedicular screw internal fixation was performed to stabilize atlas and axis in 8 cases. Granular allograft bone was planted onto the surface of posterior arches in both atlas and axis. And the other 5 cases underwent no bony fusion. RESULTS: All patients were followed up for an average of 24 months. All screws were successfully placed in atlas and axis. And the cases of atlantoaxial dislocation were reduced. Bony fusion was observed at Months 3 - 6 post-operation. Atlantoaxial rotational function restored satisfactorily in all patients. But axial rotation was partially lost. CONCLUSION: Posterior transpedicular screw internal fixation can regain atlantoaxial joint stability immediately and promote bony fusion. And it is an effective therapy for atlantoaxial complex fracture.

[Biomechanical study of atlantoaxial fixation for transverse ligament injury leading to atlantoaxial instability].

OBJECTIVE: To explore the three-dimensional movement of atlantoaxial joint, complete transverse ligament and cracked transverse ligament after posterior atlantoaxial fixation. METHODS: The fresh upper cervical cadaveric specimens were collected from 6 males dead from active craniocerebral injury. The average age was 39.7 years old (range: 26 - 57). The specimens were divided into 3 groups of intact (Group I), transverse ligament cracked (Group D) and posterior atlantoaxial fixation (Group F). They were tested consecutively. RESULTS: The range of sagittal movement increased when the transverse ligament became cracked. And it had significant difference compared with the Group I (P < 0.05). But the ranges of lateral flexion and rotation showed no significant difference. When posterior atlantoaxial fixation was performed, all three-dimensional movements decreased. And significant differences existed as compared with Group I (P < 0.05). CONCLUSION: Under normal conditions, the main movement of atlantoaxial joint is rotation with lesser sagittal movement and lest lateral flexion. The range of sagittal movement increases significantly when transverse ligament is cracked (P < 0.05), especially so for anteflexion movement. The increase of lateral flexion and rotation has no significant difference compared with Group I. When posterior atlantoaxial Fixation is performed, all three-dimensional movements decrease significantly as compared with Group I (P < 0.05), especially loss of rotation function.

[Posterior interbody fusion versus improved transforaminal lumbar interbody fusion in segmental spinal fixation for aged spondylolisthesis with lumbar spinal canal stenosis].

OBJECTIVE: To assess the clinical and radiographic outcomes of posterior lumbar fixation and posterior interbody fusion or improved transforaminal lumbar interbody fusion for Meyerding grade II/III spondylolisthesis so as to address the suitability of a dynamic stabilization. METHODS: A total of 28 consecutive patients underwent posterior lumbar fixation and posterior interbody fusion or improved transforaminal lumbar interbody fusion for Meyerding grade II/III spondylolisthesis. Among them, 13 patients underwent posterior interface fusion (PLIF) and pedicle screw fixation. And improved transforaminal lumbar interbody fusion (ITLIF) and placement of the same system were performed in 15 patients. Their clinical, economic, functional, and radiographic data were recorded both pre- and postoperatively. RESULTS: The average changes of economic and functional scores on the Prolo scale were 1.36 and 1.48 respectively. In patients with posterior interbody fusion; the average preoperative vertebral slippage was 46.9% (range: 25 - 75%) versus 14.6% (range: 15 - 25%) postoperatively. In patients with ITLIF, the average changes in economic and functional scores were 1.75 and 1.63 respectively. And the average preoperative vertebral slippage was 45.2% (range: 28 - 78%) compared with 26.3% (range: 14 - 28%) postoperatively. When two fusion techniques were compared, an overall superior reliability and resistance of systems was associated with the ITLIF procedure. But their clinical outcomes did not differ greatly (P > 0.05). CONCLUSIONS: The application of a segmental pedicle screw fixation is both feasible and efficacious.

Genome sequencing and comparative genomics analysis of Halomonas sp. MT13 reveal genetic adaptation to deep-sea environment.

Halomonas sp. MT13, a moderately psychrotolerant, piezotolerant and exopolysaccharide-producing bacterium, was isolated from deep-sea sediment of the Mariana Trench at the depth of 8300 m. Here, we report the complete genome sequence of strain MT13 and its genomic characteristics related to deep-sea environmental adaptation by comparing with its three closely related Halomonas species. The genome of strain MT13 contains one circular chromosome of 3,643,760 bp without any plasmid. Gene annotation, Cluster of Orthologous Groups (COG) and KEGG analysis showed that strain MT13 possesses a serial of genes involved in deep-sea environmental adaptation, including ectoine biosynthesis, osmolyte transport, and cold-shock response. Compared with type strains of three closely related Halomonas species, strain MT13 has higher proportions of genes assigned to translation, ribosomal structure and biogenesis, and coenzyme, lipid and inorganic ion transport and metabolism, but lacks genes involved in flagellar assembly. The genome of strain MT13 would deepen our knowledge on the adaptation strategies of microorganisms dwelling in deep-sea environment.

[Effect of siRNA-Cox-2 on the growth inhibition and apoptosis of cartilage endplate chondrocytes].

OBJECTIVE: To investigate the influence of siRNA-COX-2 gene upon the growth inhibition and apoptosis of cartilage endplate chondrocytes and provide new methods and evidence for siRNA in gene therapy of cartilage endplate chondrocytes. METHODS: According to the sequence of COX-2 mRNA, COX-2 siRNA was designed, synthesized, cloned into the GFP reporter pcDNA6.2GW/EmGFPmiR vector and transfected into Hep cell line. The integrity of inset fragment was detected by colony PCR (polymerase chain reaction) and sequencing analysis. The cultured cartilage endplate chondrocytes were divided into 4 groups: control group (untreated), negative siRNA group (treatment with 30 nmol/L negative control siRNA), siRNA1 group (treatment with 15 nmol/L COX-2 siRNA) and siRNA2 group (treatment with 30 nmol/L COX-2 siRNA). The biological activity of recombinants was identified with the interference efficiency of COX-2 siRNA recombinant by real-time PCR and Western blot. And the effects of COX-2 inhibitor on the growth of chondrocytes were detected by WST-8 and the mRNA expressions of survivin, bcl-2 and bax genes measured by real-time PCR. RESULTS: The sequences of inset fragment in 4 siRNA expressing recombinants were correct. After COX-2 transfection, the expression of COX-2 mRNA in chondrocytes was 51.3% ± 7.2% in the siRNA1 group and 35.4% ± 3.6% in the siRNA2 group. Western blot showed that the expression of COX-2 protein decreased, especially in siRNA2 group (P < 0.05). And the cell survival rate was 100.0% ± 8.3% in the control group, 84.9% ± 4.2% in the negative control siRNA group, 52.5% ± 6.7% in the siRNA1 group and 48.9% ± 5.4% in the siRNA2 group (P < 0.05). Meanwhile, the expressions of mRNA of survivin and bcl-2 decreased while the expression of bax mRNA increased in degenerative cartilage endplate chondrocytes transfected with COX-2 siRNA (P < 0.05). CONCLUSION: COX-2-targeting siRNA inhibits the expression of COX-2, suppresses the proliferation of chondrocytes and induces the cell apoptosis. These effects may be attributable to the up-regulation of survivin and bcl-2 and the down-regulation of bax.

[Biological characteristics of human umbilical cord-derived mesenchymal stem cells and their differentiation into chondrogenic and osteogenic cells].

OBJECTIVE: To investigate the isolation and expansion of mesenchymal stem cells (MSCS) from human umbilical cord Wharton's jelly and their biological identities, and explore the possibility of inducing human umbilical cord-derived MSCS to differentiate into chondrogenic and osteogenic cells. METHODS: The hUCMSCs were isolated form human umbilical cord by tissue adherence and digested with collagenase NB4, dispase II and hyaluronidase. The morphology, proliferation and immunophenotype of the 3rd passage cells were analyzed, and then the chondrogenic and osteogenic differentiation was tested and evaluated by specific staining methods.cells were induced to chondrogenic and osteogenic differentiation in vitro. RESULTS: The isolation of hUCMSCs by digestion with collagenase NB4, dispase II and hyaluronidase was efficient. After seeded for 24 hours, the adherent cells showed spindle shape and fibroblast cell-like shape and the size of hUCMSCs was homogeneous. Flow cytometry analysis revealed that the hUCMSCs were positive for CD44, CD105, CD90, CD73, but were negative for CD45, CD34, CD14, CD19 and HLA-DR. These cells could be induced to differentiate into chondrogenic and osteogenic cells under proper inducing conditions. The hUCMSCs retained the appearance and phenotype even after being expanded more than 40 passages in vitro. CONCLUSIONS: The human MSCs could be isolated from human umbilical cord Wharton's jelly, and it was easy to propagate these MSCs. An in vitro method for isolation and purification of hUCMSCs from human umbilical cord has been established. The cultured cells were composed of only undifferentiated cells and their biological properties were stable. The hUCMSCs are expected to be a new type of stem cells of tissue engineering.

[Treatment of combination atlantoaxial fractures with posterior fusion plus atlantoaxial pedicle screw].

OBJECTIVE: To explore the clinical feasibility, approach, efficacy and indications of posterior fusion plus pedicle screw fixation in the treatment of combination atlantoaxial fractures. METHODS: A retrospective analysis was conducted for 26 cases of Jefferson and dens fracture treated with atlantoaxial pedicle screw from June 2008 to May 2010. RESULTS: The postoperative radiographs verified an excellent position of all screws with a satisfactory atlantoaxial reduction. Operative time was (126 ± 26) min, and blood loss was (350 ± 107) ml. During an average follow-up period of 14 months (range: 6 - 28), it showed no spine cord and vertebral artery injury or interfixation failure. Atlantoaxial alignment and stability were restored without any instrumentation-related complication. CONCLUSION: Posterior atlantoaxial pedicle screw and rod fixation may provide immediate three-dimensional rigid fixation of atlantoaxial joint. This technique is more effective than other previously reported approaches.

[Treatment of degenerative lumbar scoliosis via posterior decompression and fusion with internal fixation].

OBJECTIVE: To explore the pathogenic mechanism, operative techniques and therapeutic efficacy of lumbar degenerative scoliosis. METHODS: A retrospective analysis was performed for 32 patients (14 males and 18 females with a mean age of 67.4 years old) with degenerative lumbar scoliosis undergoing posterior decompression and fusion with pedicle screw system from January 2007 to March 2010. The post-operative outcomes were radiologically evaluated with Oswestry disability index (ODI), Cobb' angle and lumbar lordosis angle. RESULTS: All patients received a mean follow-up of 28.5 months (range: 12 - 50). All lumbar joints achieved bony fusion at Month 6 post-operation. No complications occurred due to instrumentation. There was no pseudoarthrosis. The significant differences of ODI existed between pre-operation and post-operation [(60 ± 11)% vs (21 ± 6)%, P < 0.01], Cobb' angle [(28 ± 9)° vs (13 ± 5)°, P < 0.01] and lumbar lordosis angle [(41 ± 12)° vs (20 ± 10)°, P < 0.01]. CONCLUSION: Individualized operations should be performed for degenerative lumbar scoliosis patients. Proper lumbar decompression and the reconstruction of coronal and sagittal balances may relieve symptoms and improve the quality of life.

[Treatment of upper cervical spine instability with posterior fusion plus atlantoaxial pedicle screw].

OBJECTIVE: To evaluate the clinical efficacies, indications and application values of posterior fusion plus pedicle screw fixation in the treatment of upper cervical spine instability. METHODS: From May 2006 to December 2010, a total of 24 patients with atlantoaxial instability were treated with C1-2 pedicle screws and rod fixation under general anesthesia. There were 18 males and 6 females with a mean age of 49.8 years old (range: 17 - 69). RESULTS: The postoperative radiographs verified a good position of all screws with satisfactory atlantoaxial reduction. A mean follow-up period of 23 months (range: 3 - 45) showed no injury of spinal cord and vertebral artery or inter fixation failure. Atlantoaxial alignment and stability were restored without instrumentation-related complications. CONCLUSION: Posterior atlantoaxial pedicle screw and rod fixation provide immediate three-dimensional rigid fixation of atlantoaxial joint. It is a more effective technique than with previously reported techniques.