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.

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).

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.

[Three dimensional finite element analysis of optimal distribution model of fillers in vertebroplasty].

OBJECTIVE: To establish a three-dimensional finite element model of osteoporosis and to study the stiffness recovery of injured vertebrae and stress analysis of adjacent vertebrae after percutaneous vertebroplasty under different perfusion and distribution conditions by simulating fluid flow into the vertebral body. METHODS: A male healthy volunteer was selected. CT scans were performed from T11 to L2. Mimics 15.0 and ABAQUS 6.11 software were used to extract CT images. The vertebral model of osteoporotic fracture was established. The flow physical field and conduction and diffusion physical field were coupled to simulate the process and parts of the injection of bone cement into the vertebral fracture model. The amount of bone cement injected into the vertebral fracture model was 2 ml, 4 ml, 6 ml respectively. The diffusion range of bone cement was simulated on the image, and the post injection model of bone cement was obtained. Vertical downward, forward and backward pressure of 300 N were applied on the surface of the model to simulate vertebral movement. The stress changes of upper and lower vertebrae and diseased vertebrae under different conditions were calculated. RESULTS: (1) The VonMises stress of T12 inferior endplate was the largest in the three states before and after fracture.(2) The VonMises stress of the intervertebral disc and each endplate after fracture was significantly higher than before fracture. When percutaneous vertebroplasty was applied, as the amount of bone cement injection increases, the VonMises stress of the adjacent vertebral endplates increases. In the diseased vertebrae, as the amount of bone cement increases, the VonMises stress of the vertebral body endplate showed a downward trend. CONCLUSION: Reliable biomechanical model of lumbar vertebral fracture can be established by using CT scanning data through software simulation. Vertebral fracture and vertebroplasty will cause biomechanical changes of adjacent vertebral bodies. With the increase of bone cement injection, the influence of biomechanical changes will increase significantly. Neighbouring vertebral fractures are more likely. For this experiment, percutaneous vertebroplasty has a suitable amount of cement injection of 4 ml.

[Application of Gemstone Spectrum Imaging for anterior spinal artery in patients with cervical spinal injury].

OBJECTIVE: To discuss the value of Gemstone Spectrum Imaging (GSI) CT anterior spinal artery angiography in the patients with cervical spinal cord injury, and to evaluate the correlation between the change of the blood flow of the anterior spinal artery and the postoperative recovery of nerve function. METHODS: From January 2014 to June 2016, thirty patients who underwent cervical open door laminoplasty for spinal cord injury were retrospective analyzed and included 21 males and 9 females with an average age of (46.4±9.7) years old ranging from 33 to 59 years. Within 2 weeks after injury, open door laminoplasty was performed through cervical posterior approach. Among them, there were 8 cases of 3 segments of open door decompression, 18 cases of 4 segments, 4 cases of 5 segments. GSI CT were performed at 3 days before operation and 5 days after operation. The anterior spinal artery was reconstructed and evaluated the improvement of blood flow after operation. The cervical JOA score was calculated at 1 day before operation, 5 days after operation and 1, 6 and 12 months after operation, and the JOA score improvement rate of the corresponding follow-up points was calculated. RESULTS: All patients were followed up for 12 to 30 months with an average of (17.4±7.6) months. The iodine content ratio (ASA/VA) of the anterior spinal artery before and after operation was 0.75±0.20 and 0.89±0.02 respectively, the postoperative improvement was significantly higher than that before operation(P<0.01). The average ASA/VA improvement rate was(21.05±12.45)% after operation. There was a positive linear correlation between the improvement of blood flow and the improvement of JOA score at 1, 6 and 12 months after operation. CONCLUSIONS: GSI CT anterior spinal artery angiography is safe and feasible, the imaging is satisfactory, it can quantitatively evaluated the blood flow of the anterior spinal artery. There was a positive linear correlation between the improvement of blood flow in anterior spinal artery and the recovery of neurological function. Early postoperative improvement of blood flow in the anterior spinal artery can be used as a reference index for predicting the recovery of neurological function in patients.

Leptin-induced inflammation by activating IL-6 expression contributes to the fibrosis and hypertrophy of ligamentum flavum in lumbar spinal canal stenosis.

The ongoing chronic inflammation and subsequent fibrosis play an important role in ligamentum flavum (LF) fibrosis and hypertrophy in patients with lumbar spinal canal stenosis (LSCS). Leptin is a chronic inflammatory mediator and involved in the fibrotic process in multiple organ systems. The present study aimed to investigate the role of leptin in LF fibrosis and its related regulatory mechanisms. The LF specimens were obtained during the surgery from 12 patients with LSCS (LSCS group) and 12 control patients with lumbar disc herniation (LDH) group. The morphologic changes and fibrosis score of LF were assessed by Hematoxylin and eosin (H&E) and Masson's trichrome staining respectively. The location and expression of leptin in LF tissues were determined. Then, the LF cells were cultured and exposed to recombinant human leptin (rhleptin). Collagen I and III were used as fibrosis markers and IL-6 was used as the inflammatory factor. As a result, the LF thickness and fibrosis score in the LSCS group were significantly higher than those in the LDH group (P<0.05). Leptin was detected in the hypertrophied LF and its expression was substantially increased in the LSCS group and positively correlated with LF thickness and fibrosis score (P<0.05). Moreover, our in vitro experiments revealed that rhleptin treated LF cells elevated the expression of collagen I and III. Finally, leptin administration induced IL-6 expression via nuclear factor-κB (NF-κB) pathway in LF cell (P<0.05). Our study demonstrated novel molecular events for leptin-induced inflammation in LF tissue by promoting IL-6 expression and thus might have potential implications for clarifying the mechanism underlying LF fibrosis and hypertrophy.

Bioinformatics analysis of the gene expression profiles in human intervertebral disc degeneration associated with inflammatory cytokines.

BACKGROUND: To investigate the microarray data on the gene expression profiles of intervertebral disc degeneration related to cytokine exposure. The purpose of the study was to identify the key genes that were differentially expressed in these disc cells compared to cells without inflammatory cytokine treatment, using bioinformatics analyses, and to explore the related signaling pathways and interaction networks, providing clues to the molecular mechanisms of disc degeneration for future experimental studies. METHODS: The gene expression profiles data were obtained using the same microarray platform for two groups of patients suffering from degenerative disc diseases: GSE41883 (Human annulus disc cells exposed to TNF-a; 4 samples) and GSE27494 (Human annulus disc cells exposed to IL-1ß; 4 samples). The genes that were differentially expressed in these two datasets compared to control disc cells (without cytokine exposure; 4 samples each) were identified using the R language, and were pooled using the Excel software program to select the common differentially expressed genes in the two datasets. The initial functional clustering, signaling pathways and protein-protein interaction relationship analyses were conducted using the DAVID and STRING software programs. RESULTS: Of the 255 concomitantly and differentially expressed genes identified after respective treatment with TNF-α and IL-1ß, 141 were up-regulated and 114 were down-regulated. The gene ontology annotation analysis showed that these differentially expressed genes were primarily associated with cytokine activity, growth factor activity, the inflammatory reaction and the response to injury. The signaling pathway analysis showed that these differentially expressed genes were mainly related to the interactions of cytokines, apoptosis and NOD-like receptor signaling pathways. The interaction network analysis indicated that PTGS2, ICAM1, NOV and other genes may play a role in disc degeneration. CONCLUSIONS: We found that ICAM1 and other genes may play a role in the development of disc degeneration induced by inflammatory reactions using a bioinformatics analysis of the gene expression profiles of degenerative intervertebral disc cells stimulated with inflammatory factors, suggesting that bioinformatics methods can be used to identify potential target for intervertebral disc degeneration.

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.

Outcomes of surgery for unstable odontoid fractures combined with instability of adjacent segments.

BACKGROUND: At present, traumatic atlantoaxial dislocation or C2-3 instability complicating odontoid fractures remains rarely reported. The aim of this study was to further investigate the surgical treatment strategies and curative effects for odontoid fractures combined with instability of adjacent segments. METHODS: This is a retrospective study of 12 patients (5 females and 7 males; age, 21-65 years) who underwent internal fixation for odontoid fractures (type II and shallow type III) and atlantoaxial instability in 6 cases, C2-3 instability in 4 cases, simultaneous C1-2 and C2-3 instability in 2 cases between January 2005 and June 2012. Accordingly, individualized surgeries were performed. Fracture healing and bone fusion were determined on X-ray scan. Upper limbs, lower limbs and sphincter functions were assessed using the Japanese Orthopaedic Association (JOA) score. Frankel grading system was used for the evaluation of neurological situation. RESULTS: Mean follow-up time of all 12 cases was 16.4 months (range, 12 to 48 months). Odontoid fracture healing was obtained in all patients within 9 months, and graft fusion was achieved within 6 months. JOA score was significantly improved from 6.3 ± 3.1 preoperatively to 11.1 ± 4.6 at 12 months after operation (P = 0.007), with 50.5 ± 25.7% recovery rate and 66.7% excellent and good rate. Except one patient still had Frankel grade B neurological injury at 12 months after surgery, the other patients improved their neurological situation (at 1 grade in Frankel scale). One patient developed wound fat liquefaction which resolved by changing the dressing. Cerebrospinal fluid leakage occurred in three patients, which resolved after the continuous drainage for 2 days. CONCLUSIONS: According to the characteristics of odontoid fractures, the individualized operative procedure should be performed, resulting in high fracture healing rate, function recovery rate, and less, transient complications.

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.

Classification and surgical management for the axis fracture complicated with adjacent segment instability.

This study was to classify the axis fracture complicated with adjacent segment instability and to explore its significance to surgical management. 42 patients (25 males and 17 females) with axis fractures with an average age of 44.14 years (range, 23 to 65) who received surgery between January 2006 and June 2012 were analyzed retrospectively. Results suggest that all patients underwent surgery safely without spinal cord injury, cerebrospinal fluid leakage or vertebral artery injury. The average follow up was 18 months (12-48 months). There was significant difference (t = 2.339, P = 0.011) in JOA score between pre-operation (13.10 ± 4.51) and post-operation time points (15.24 ± 3.86). 1-2 degree improvement of neurofunction was achieved in all except 1 Frankel B. After operation, all patients were immobilized in a hard collar for 3 months. Fusion was achieved in all cases (mean 4.5 months). X-ray showed no malposition of the screws. No instrument failure was noted during follow up. Thus, axis fracture complicated with adjacent segment instability should be treated individually based on the fracture type and adjacent segment instability. Our classification can be used to guide the surgical management.

[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.

[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.

[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.

PPARγ forms a bridge between DNA methylation and histone acetylation at the C/EBPα gene promoter to regulate the balance between osteogenesis and adipogenesis of bone marrow stromal cells.

The balance between osteogenesis and adipogenesis of bone marrow stromal cells is impaired in many human diseases. Knowledge of how to fine-tune this balance is of medical importance. CCAAT/enhancer binding protein α (C/EBPα) has been shown to regulate the balance between osteogenesis and adipogenesis of C3H10T1/2 cells, with epigenetic modifications of the C/EBPα promoter playing an important role. The present study aimed to elucidate the underlying molecular mechanisms. The results showed that peroxisome proliferator-activated receptor γ (PPARγ) binds the -1286 bp/-1065 bp region of the C/EBPα promoter to activate C/EBPα expression during osteogenesis and adipogenesis of C3H10T1/2 cells. DNA hypermethylation in the -1286 bp/-1065 bp region, observed at the terminal stage of osteogenesis, prevented PPARγ binding, and then histone deacetylase 1 (HDAC1) occupied this region to reduce the level of histone acetylation. We regulated the balance between osteogenesis and adipogenesis of mouse bone marrow stromal cells through modulation of DNA methylation and histone acetylation status. In addition, in bone marrow stromal cells from the glucocorticoid-induced osteoporosis (GIO) mouse, hypomethylation of CpG sites, higher binding of PPARγ, acetylated histones 3 and 4, and reduced binding of HDAC1 in the -1286 bp/-1065 bp region of C/EBPα promoter were observed, compared with normal mice. This study provides a deeper insight into the molecular mechanisms underlying the balance between osteogenesis and adipogenesis regulated by C/EBPα in synergy with PPARγ, and suggests a molecular model for how DNA methylation and histone acetylation are linked by PPARγ to regulate differentiation of bone marrow stromal cells.

[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.

Non-spinal-associated injuries with lumbar transverse process fractures: influence of segments, amount, and concomitant vertebral fractures.

BACKGROUND: Lumbar transverse process fractures (LTPFs) are often with concomitant non-spinal-associated injuries (NSAIs). The purpose of this study was to analyze the correlation between the NSAIs and the LTPFs of different segments, amount, and concomitant thoracolumbar/lumbar vertebral fractures. METHODS: A total of 1,181 patients with LTPFs or thoracolumbar/lumbar vertebral fractures were chosen between September 2006 and June 2010. The patients were divided into three groups: thoracolumbar/lumbar vertebral fractures without LTPFs, with associated LTPFs, and isolated LTPFs (iLTPFs). The correlation of the NSAIs of different sites and the LTPFs of different segments, amount, and concomitant thoracolumbar/lumbar vertebral fractures were analyzed between and within groups by χ test and logistic regression analysis. RESULTS: The incidence of NSAIs with iLTPFs and aLTFP groups were significantly higher than that of vertebral fractures without LTPF group (55.73% and 64.49% vs. 21.32%, respectively, p = 0.000). However, the incidence was not significantly different between the iLTPFs and the aLTFP groups (p = 0.106). The results with NSAIs of different sites were almost the same. L5TPFs were a stronger risk factor to NSAIs (relative risk [RR] = 15.72; 95% confidence interval [CI], 4.47-55.37; p = 0.000) in the iLTPF group (RR = 21.92; 95% CI, 6.68-71.92; p = 0.000) and in the vertebral fractures with associated LTPF group (RR = 9.42; 95% CI, 1.19-74.72; p = 0.034). L5TPFs were also a very important risk factor for pelvic injuries (RR = 46.10; 95% CI, 22.40-94.88; p = 0.000); 65.1% in L5iTPFs were accompanied with Tile-C pelvic injuries, slightly higher than in L5aTPFs (46.7%). L4TPFs were a risk factor to abdominal injuries within iLTPFs (RR = 2.27; 95% CI, 1.23-4.20; p = 0.009). CONCLUSIONS: The incidence of NSAIs is very high in cases with LTPFs, particularly with L5TPFs. A detailed investigation should be performed to search for NSAIs once LTPFs are identified so that appropriate treatment can be initiated. LEVEL OF EVIDENCE: Level III.

[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.

[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.