[High mechanical stretch stress promotes degeneration of the human nucleus pulposus cells through NF-κb signaling pathway]

Objective: To investigate the effect of high mechanical stretch stress(HMS)on human nucleus pulposus cells and its regulatory mechanism. Methods: The non-degenerated nucleus pulposus tissue (Pfirrmann<grade Ⅲ) removed from the patient's surgery was harvested and the human nucleus pulposus cells were isolated and cultured. In the presence or absence of pretreatment with the NF-κB specific blocker Bay11-7082, the cultured human nucleus pulposus cells were loaded cyclic mechanical stretch stress(CMS) with different parameters using the Flexercell system.The cell culture medium was collected and the secretion of inflammatory cytokines was detected by Elisa. The nucleus pulposus cells loaded with cyclic mechanical stretch stress(CMS) was collected, the changes of NF-κB/P65 signal pathway were detected, The mRNA and protein levels' expression changes were detected by RT-PCR and WB; after human nucleus pulposus cells were exposed to IL-1β, with or without Bay11-7082, the changes of P65 were detected by immunofluorescence. Results: Those mechanical stretch stress of high amplitude (9%, 19%), low frequency (0.01 Hz) and long duration (72 h) led to degeneration of human nucleus pulposus cells, while the mechanical stretch stress of low amplitude (3%), low frequency and long duration could not promote the degeneration process; the mechanical stretch stress of high amplitude(19%), low-frequency(0.01 Hz) could promote the release of inflammatory cytokines of human nucleus pulposus cells after 24 h duration; high-amplitude, low-frequency mechanical stretch stress could activate the NF-κB signaling pathway in human nucleus pulposus cells, Bay11-7082 could block the process; immunofluorescence showed that IL-1β could promote the phosphorylation of P65 in the cytoplasm of human nucleus pulposus cells and promote the entry of P65 into the cell nucleus process, Bay11-7082 could block those processes; Bay11-7082, the specific blocking agent of NF-κB signaling pathway, could block the degeneration process of human nucleus pulposus cells induced by high cyclic mechanical stretch stress(CMS) in a dose-dependent. Conclusions: High cyclic mechanical stretch stress promotes human nucleus pulposus cells degeneration through NF-κB signaling pathway.

[Analysis of a three-dimensional finite element model of atlas and axis complex fracture]

Objective: To explored the clinical application of the three-dimensional finite element model of atlantoaxial complex fracture. Methods: A three-dimensional finite element model of cervical spine (FEM/intact) was established by software of Abaqus6.12.On the basis of this model, a three-dimensional finite element model of four types of atlantoaxial complex fracture was established: C(1) fracture (Jefferson)+ C(2) fracture (type Ⅱfracture), Jefferson+ C(2) fracture(type Ⅲfracture), Jefferson+ C(2) fracture(Hangman), Jefferson+ stable C(2) fracture (FEM/fracture). The range of motion under flexion, extension, lateral bending and axial rotation were measured and compared with the model of cervical spine. Results: The three-dimensional finite element model of four types of atlantoaxial complex fracture had the same similarity and profile.The range of motion (ROM) of different segments had different changes.Compared with those in the normal model, the ROM of C(0/1) and C(1/2) in C(1) combined Ⅱ odontoid fracture model in flexion/extension, lateral bending and rotation increased by 57.45%, 29.34%, 48.09% and 95.49%, 88.52%, 36.71%, respectively.The ROM of C(0/1) and C(1/2) in C(1) combined Ⅲodontoid fracture model in flexion/extension, lateral bending and rotation increased by 47.01%, 27.30%, 45.31% and 90.38%, 27.30%, 30.0%.The ROM of C(0/1) and C(1/2) in C(1) combined Hangman fracture model in flexion/extension, lateral bending and rotation increased by 32.68%, 79.34%, 77.62% and 60.53%, 81.20%, 21.48%, respectively.The ROM of C(0/1) and C(1/2) in C(1) combined axis fracture model in flexion/extension, lateral bending and rotation increased by 15.00%, 29.30%, 8.47% and 37.87%, 75.57%, 8.30%, respectively. Conclusions: The three-dimensional finite element model can be used to simulate the biomechanics of atlantoaxial complex fracture.The ROM of atlantoaxial complex fracture is larger than nomal model, which indicates that surgical treatment should be performed.

Identifying hub genes and potential mechanisms associated with senescence in human annulus cells by gene expression profiling and bioinformatics analysis

The aim of the present study was to reveal the potential hub genes and regulatory mechanisms associated with senescence in human annulus cells by analyzing microarray data using bioinformatics. The gene expression dataset GSE17077, of senescent and non‑senescent annulus cells obtained from patients with disc degenerative diseases (DDD), was downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were identified. Functional and pathway annotations were performed using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes terms, respectively. Web‑based Gene Set Analysis Toolkit and Chip Enrichment Analysis were used to identify key transcription factors (TFs). A protein‑protein interaction (PPI) network was constructed to analyze the hub genes associated with senescence in DDD. A total of 667 DEGs were screened, including 368 up‑ and 299 down‑regulated genes. These DEGs were enriched in phosphorylation, regulation of apoptosis and regulation of programmed cell death. In addition, DEGs were involved in axon guidance, natural killer cell‑mediated cytotoxicity, purine metabolism and the mitogen‑activated protein kinase (MAPK) signaling pathway. The TFs activator protein 1 (AP1), specificity protein 1 and aryl hydrocarbon receptor may serve regulatory roles in gene expression in senescent cells. Certain key target genes of TFs, including heat shock protein 90 (HSP90) and C‑X‑C motif chemokine 5 (CXCL5), within the DEGs were revealed to have a high connectivity degree by PPI analysis. The results of the present study indicated that the MAPK‑regulated AP1 pathway may contribute to senescence‑associated disc degeneration. The DEGs, including HSP90 and CXCL5, with a high degree of connectivity may be potential targets for future investigations into molecular biomarkers.

[Gene expression profiles of long non-coding RNAs in human degenerated intervertebral disc tissue]

Objective: To investigate the gene expression profiles of long non-coding RNAs (lncRNA)in human degenerated intervertebral disc degeneration (IDD). Methods: An lncRNA-mRNA microarray analysis of human nucleus pulposus (NP) was employed. Bioinformatics prediction was also applied to delineate the functional roles of the differentially expressed lncRNAs. Several lncRNAs and mRNAs were chosen for quantitative real-time PCR (qRT-PCR) validation. Results: A total of 1 570 lncRNAs expressed in degenerate group compared with the nondegenerate group. Of these, the expression level of 428 lncRNAs was upregulated >2-fold compared with nondegenerate group while that of 584 was downregulated. Bioinformatics analysis (GO and pathway analyses) revealed that some classical pathways participating in extracellular matrix (ECM) and cell apoptosis were aberrantly expressed in the intervertebral disc (P<0.05). Enhancer-like lncRNAs and their nearby coding genes were analyzed. Three lncRNAs were identified as potential enhancers. Several lncRNAs were validated in the intervertebral disc using RT-qPCR. Conclusion: The lncRNAs express differentially in the intervertebral disc. LncRNAs may therefore be novel candidate biomarkers and potential targets for intervertebral disc degeneration therapy in the future.

Deep Western Boundary Current in the South China Sea

Deep western boundary current (DWBC) was observed for the first time by an array of 6 current meter moorings southeast of the Zhongsha Islands in the South China Sea (SCS) deep basin during the period from August 2012 to January 2014. In the mean, the DWBC in the SCS flows southwestward with core velocity of 2.0 cm/s and a volume transport of 1.65 Sv (1 Sv = 1 × 106 m3/s). Its temporal variability is dominated by intraseasonal fluctuations with period around 90 days. The main axis of the DWBC, characterized by a low temperature core, tends not to shift with the 90-day fluctuation.

Mechanism of microRNA-146a-mediated IL-6/STAT3 signaling in lumbar intervertebral disc degeneration

The aim of the study was to investigate the mechanism of microRNA (miR)-146a-mediated activation of interleukin-6/signal transducer and activator of transcription 3 (IL-6/STAT3) in lumbar intervertebral disc degeneration. To obtain intervertebral tissue, we recruited 5 patients with lumbar intervertebral disc herniation (experimental group) and 5 patients with lumbar burst fracture (control group). Nucleus pulposus tissue was extracted by surgery and cultured. miR-146a empty vector, mimic, and inhibitor were transfected into the two groups of cells for 24 h and the levels of IL-6, type II collagen (Col II), aggrecan, STAT3, matrix metalloproteinase (MMP)-3, and a disintegrin and metalloproteinase with thrombospondin type I motifs (ADAMTS) were detected. We found no differences in the levels of IL-6, Col II, aggrecan, STAT3, MMP-3, and ADAMTS before and after treatment in the control group. However, the levels of miR-146a, IL-6, STAT3, MMP-3, and ADAMTS were significantly elevated, whereas Col II and aggrecan levels were lower in the experimental group before treatment. The levels of IL-6, STAT3, MMP-3, and ADAMTS were elevated after treatment with miR-146a mimic when compared with the miR-146a empty vector in the experimental group, and Col II and aggrecan levels were decreased. However, the cells treated with miR-146a inhibitor had the opposite result. Thus, the IL-6/STAT3 signaling pathway can be mediated by a high expression of miR-146a to regulate the occurrence of lumbar intervertebral disc degeneration.

Research on the function and related mechanism of P27 gene in the intervertebral disc degeneration of mice

This study aims to investigate the function and related mechanism of P27 gene in intervertebral disc (IVD) degeneration of mice. X-ray, immunohistochemical staining, and alkaline phosphatase (ALP) histochemical staining were used to analyze the phenotypic difference of the intervertebral discs of 4-week-old mice with P27 gene knockout (P27-/-) and wild-type (WT) mice in the same brood. Protein in the intervertebral disc was extracted and western blot analysis was employed to detect the changes in the expression of related molecules in the Shh-signal pathways, including Shh, Patched, Smoothened and Gli2. As a result, the ALP histochemical staining revealed that the ALP-positive area of mice in the P27-/- group was obviously increased compared to the 4-week-old mice of the same brood in the WT group. In addition, the Col-I immunohistochemical staining showed that the Col-I-positive area of mice in the P27-/- group was significantly increased compared to mice in the WT group. Furthermore, Smo-positive cell rate of mice in the P27-/- group was apparently increased compared to mice in the WT group. Western blot analysis revealed that in terms of changes of protein expression levels of Shh, Patched, Smoothened and Gli2 in the intervertebral disc, protein expression levels of Shh, Patched, Smoothened and Gli2 of mice in the P27-/- group were significantly increased compared to those of mice in the WT group. The results show that P27 deficiency activates the expression of Shh-signal pathway and promotes the proliferation of osteoblast, thus, playing a role in promoting IVD degeneration, which provides a scientific and reliable experimental basis for the treatment of the IVD degeneration-related diseases in clinical practice.

Lack of evidence for involvement of TonEBP and hyperosmotic stimulus in induction of autophagy in the nucleus pulposus

Nucleus pulposus (NP) cells reside in a physiologically hyperosmotic environment within the intervertebral disc. TonEBP/NFAT5 is an osmo-sensitive transcription factor that controls expression of genes critical for cell survival under hyperosmotic conditions. A recent report on NP and studies of other cell types have shown that hyperosmolarity triggers autophagy. However, little is known whether such autophagy induction occurs through TonEBP. The goal of this study was to investigate the role of TonEBP in hyperosmolarity-dependent autophagy in NP. Loss-of-function studies showed that autophagy in NP cells was not TonEBP-dependent; hyperosmolarity did not upregulate autophagy as previously reported. NP tissue of haploinsufficient TonEBP mice showed normal pattern of LC3 staining. NP cells did not increase LC3-II or LC3-positive puncta under hyperosmotic conditions. Bafilomycin-A1 treatment and tandem mCherry-EGFP-LC3B reporter transfection demonstrated that the autophagic flux was unaffected by hyperosmolarity. Even under serum-free conditions, NP cells did not induce autophagy with increasing osmolarity. Hyperosmolarity did not change the phosphorylation of ULK1 by mTOR and AMPK. An ex vivo disc organ culture study supported that extracellular hyperosmolarity plays no role in promoting autophagy in the NP. We conclude that hyperosmolarity does not play a role in autophagy induction in NP cells.

MiR-21 promotes fibrosis and hypertrophy of ligamentum flavum in lumbar spinal canal stenosis by activating IL-6 expression

The molecular mechanism underlying the fibrosis of ligamentum flavum(LF) in patients with lumbar spinal canal stenosis(LSCS) remains unknown. MicroRNAs are reported to play important roles in regulating fibrosis in different organs. The present study aimed to identify fibrosis related miR-21 expression profile and investigate the pathological process of miR-21 in the fibrosis of LF hypertrophy and associated regulatory mechanisms. 15 patients with LSCS underwent surgical treatment were enrolled in this study. For the control group, 11 patients with lumbar disc herniation(LDH) was included. The LF thickness was measured on MRI. LF samples were obtained during the surgery. Fibrosis score was assessed by Masson's trichrome staining. The expression of miR-21 in LF tissues were determined by RT-PCR. Correlation among LF thickness, fibrosis score, and miR-21 expression was analyzed. In addition, Lentiviral vectors for miR-21 mimic were constructed and transfected into LF cells to examine the role of miR-21 in LF fibrosis. Types I and III collagen were used as indicators of fibrosis. IL-6 expression in LF cells after transfection was investigated by RT-PCR and ELISA. Patients in two groups showed similar outcomes regarding age, gender, level of LF tissue. The thickness and fibrosis score of LF in the LSCS group were significantly greater than those in LDH group (all P < 0.05). Similarly, the expression of miR-21 in LSCS group was substantially higher than that in LDH group(P < 0.05). Furthermore, the miR-21 expression exhibited positive correlations with the LF thickness (r = 0.595, P < 0.05) and fibrosis score (r = 0.608, P < 0.05). Of note, miR-21 over-expression increased the expression levels of collagen I and III (P < 0.05). Also, IL-6 expression and secretion in LF cells was elevated after transfection of miR-21 mimic. MiR-21 is a fibrosis-associated miRNA and promotes inflammation in LF tissue by activating IL-6 expression, leading to LF fibrosis and hypertrophy.

IL-1β increases asporin expression via the NF-κB p65 pathway in nucleus pulposus cells during intervertebral disc degeneration

Disc degeneration (DD) is a multifaceted chronic process that alters the structure and function of intervertebral discs. The pathophysiology of degeneration is not completely understood, but the consensus is that changes in genes encoding extracellular matrix (ECM) proteins in the disc are the leading factors contributing to DD. Asporin is an ECM protein that has been shown to be increased in degenerated intervertebral discs, but little is known about how asporin is regulated during DD. In exploring the intricate mechanism, we confirmed that asporin was abundantly increased in patients’ degenerated nucleus pulposus. Consistently, the increased asporin expression with degeneration was also proved by rabbit intervertebral disc degeneration (IDD) model. Mechanistically, IL-1β upregulated asporin expression by activating the p65 pathway in human nucleus pulposus cells. Furthermore, p65 mediated asporin expression by binding to −41/−31 bp on asporin promoter. Functionally, asporin was the intermediator of IL-1β-inhibited aggrecan and collagen Π expression and played a negative role in TGF-β-induced aggrecan and collagen Π formation in human nucleus pulposus cells. Therefore, identifying asporin as a negative regulator of aggrecan and collagen Π and elucidating its induction mechanisms in human nucleus pulposus cells provides new insight for asporin induction during IDD.

Marine Group II Dominates Planktonic Archaea in Water Column of the Northeastern South China Sea

Temperature, nutrients, and salinity are among the important factors constraining the distribution and abundance of microorganisms in the ocean. Marine Group II (MGII) belonging to Euryarchaeota commonly dominates the planktonic archaeal community in shallow water and Marine Group I (MGI, now is called Thaumarchaeota) in deeper water in global oceans. Results of quantitative PCR (qPCR) and 454 sequencing in our study, however, showed the dominance of MGII in planktonic archaea throughout the water column of the northeastern South China Sea (SCS) that is characterized by strong water mixing. The abundance of ammonia-oxidizing archaea (AOA) representing the main group of Thaumarchaeota in deeper water in the northeastern SCS was significantly lower than in other oceanic regions. Phylogenetic analysis showed that the top operational taxonomic units (OTUs) of the MGII occurring predominantly below 200 m depth may be unique in the northeastern SCS based on the observation that they are distantly related to known sequences (identity ranging from 90–94%). The abundance of MGII was also significantly correlated with total bacteria in the whole column, which may indicate that MGII and bacteria may have similar physiological or biochemical properties or responses to environmental variation. This study provides valuable information about the dominance of MGII over AOA in both shallow and deep water in the northeastern SCS and highlights the need for comprehensive studies integrating physical, chemical, and microbial oceanography.

[Expression of NF-κB in a degenerative human intervertebral disc model]

Objective: To investigate the changes in the expression of NF-κB signaling pathway in human degenerative intervertebral discs. Methods: From October 2014 to March 2016, 55 nucleus pulposus of surgical patients with degenerative human intervertebral disc were collected for study in Department of Orthopedic Surgey, Hospital of Zaozhuang Mining Corporation, and Department of Orthopedics, Shanghai General Hospital Affiliated Shanghai Jiaotong University, School of Medicine.The collected nucleus pulposus tissues were divided into two groups: experimental group(30) and control group(25). Cell culture observed normal and degenerative nucleus pulposus cells morphological changes; immunofluorescence observed NF-κB p65 changes in the nucleus of nucleus pulposus cells.Real-time PCR was observed changes in aggregated proteoglycans and matrix metalloproteinase gene mRNA.Finally, the use of blockers of nucleus pulposus cells were treated 24 hours, Western blot analysis the changing of p65, ADAMTS-4, MMP-13, aggregate proteoglycans and collagen Ⅱ protein expression. Results: Compared with the experimental group, the nucleus pulposus cells in the control group had larger cell volume, abundant cytoplasm and faster growth rate.Cell immunofluorescence show Nondegenerative nucleus pulposus cells p65 protein was mainly localized in the cytoplasm, degeneration of nucleus pulposus cells p65 protein was mainly concentrated in the nucleus.RT-PCR showed degenerative group of matrix metalloproteinases (MMP-1, MMP-3, MMP-13), aggrecanase(ADAMTS-4, ADAMTS-5) and IL-6 mRNA expression was significantly higher than Nondegenerative group; aggrecan and type Ⅱ collagen expression than those without degeneration group was significantly lower.Expression of nucleus pulposus degeneration in nuclear protein p65 with the degenerative level increased gradually increased.BAY11-7082 blocked the activity of NF-κB signaling pathway, which could significantly down-regulate the expression of ADAMTS-4 and MMP-13 protein and significantly up-regulate the expression of Agg and COLⅡ protein.With the increase of BAY11-7082 concentration, gradually strengthened. Conclusion: The activation of the NF-κB signaling pathway in a degenerative intervertebral disc is gradually increased, regulating the over-expression of matrix-degrading enzymes.It plays an important role in the degradation of extra-cellular matrix.

The Changes in the Expression of NF-KB in a Degenerative Human Intervertebral Disc model

We aim at determining the changes in the expression of NF-kB signaling pathway in degenerative intervertebral discs. We collected normal and degenerated intervertebral discs tissues. The normal and degenerated cells were cultivated and their histopathology and immunofluoresence studies were used to observe the position of NF-kB p65 in the cell. We also treated the nucleus pulposus cells with inflammatory factors and inhibitors. Western blot was used to analyze the expression of different proteins. Real time fluorescence-based quantitative PCR was used for observation of NF-kB regulation of change in gene expression. Immunofluorescence showed that in the non-degenerative group the p65 was found in the cytoplasm of the nucleus pulposus cell while in the degenerated cell group the p65 protein was found in the nucleus of the cell. The expression of p65 increased with increase in the degree of degenerative change of the nucleus pulposus cell. RT-PCR showed that the expression of matrix metalloproteinases, aggrecanases and IL-6 was higher in the degenerative group. The amount of aggrecan and type II collagen was significantly decreased in the degenerative group. IL-1β was able to upregulate the activation of NF-kB and the expression of MMP-13 and ADAMTS-4 was also significantly increased. The effect of these proteins can be inhibited by the NF-kB inhibitor, BAY11-7082. The activation of the NK-kB signaling pathway in a degenerative intervertebral disc is gradually increased, regulating the over-expression of matrix-degrading enzymes. It plays an important role in the degradation of extracellular matrix.

[Clinical effects of different methods of the proximal fusion for long segmental lumbar vertebrae fusion in treatment of degenerative lumbar scoliosis]

Objective: To explored the clinical effects of different methods of the proximal fusion for long segmental lumbar vertebrae fusion in treatment of degenerative lumbar scoliosis(DLS). Methods: From January 2007 to March 2014 fifty-five cases of DLS treated by the posterior proximal fusion of long segmental lumbar vertebrae fusion were analyzed in Department of Orthopaedics, Shanghai general Hospital of Nanjing Medical University (35)HuaiAn The First Hospital Affiliated to Nanjing Medical University(20). According to various upper instrumented vertebra(UIV) the patients were divided into Group A(upper horizontal vertebra, UHV, n=17), Group B (upper natural vertebra, UNV n=18 ), and Group C(upper end vertebra, UEV, n=20). The VAS, ODI, spinal balance parameters and postoperative complications in each group were assessed. Results: Except for 1 case death of serious lung infection in early postoperative, 54 cases were received 2-4 years follow-up. No statistical differences in improvements and fusion rates were found among 3 groups (P>0.05). The improvements of the coronal Cobb's angle in the A group were significantly more than the C group (75.8%±12.8%, 69.6%±11.8%, 63.4%±15.3%, P<0.05). The incidences of early postoperative complications in A group were the highest, next in B group, and lowest C group (52.9%, 22.0%, 15.0%, P<0.05). The incidences of proximal ASD in the C group were significantly more than the A group (12.5%, 22.2%, 50.0%, P=0.045). Conclusion: UHV, UNV and UEV had similar clinical outcomes for treatment of degenerative lumbar scoliosis in short term. Correction of the coronal deformity of UHV was superior to UEV. UEV was beneficial to reduce early complications, but more likely to happen proximal adjacent segment degeneration in the long run.

Investigation of candidate genes for osteoarthritis based on gene expression profiles

OBJECTIVE

To explore the mechanism of osteoarthritis (OA) and provide valid biological information for further investigation.

METHODS

Gene expression profile of GSE46750 was downloaded from Gene Expression Omnibus database. The Linear Models for Microarray Data (limma) package (Bioconductor project, http://www.bioconductor.org/packages/release/bioc/html/limma.html) was used to identify differentially expressed genes (DEGs) in inflamed OA samples. Gene Ontology function enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enrichment analysis of DEGs were performed based on Database for Annotation, Visualization and Integrated Discovery data, and protein-protein interaction (PPI) network was constructed based on the Search Tool for the Retrieval of Interacting Genes/Proteins database. Regulatory network was screened based on Encyclopedia of DNA Elements. Molecular Complex Detection was used for sub-network screening. Two sub-networks with highest node degree were integrated with transcriptional regulatory network and KEGG functional enrichment analysis was processed for 2 modules.

RESULTS

In total, 401 up- and 196 down-regulated DEGs were obtained. Up-regulated DEGs were involved in inflammatory response, while down-regulated DEGs were involved in cell cycle. PPI network with 2392 protein interactions was constructed. Moreover, 10 genes including Interleukin 6 (IL6) and Aurora B kinase (AURKB) were found to be outstanding in PPI network. There are 214 up- and 8 down-regulated transcription factor (TF)-target pairs in the TF regulatory network. Module 1 had TFs including SPI1, PRDM1, and FOS, while module 2 contained FOSL1. The nodes in module 1 were enriched in chemokine signaling pathway, while the nodes in module 2 were mainly enriched in cell cycle.

CONCLUSION

The screened DEGs including IL6, AGT, and AURKB might be potential biomarkers for gene therapy for OA by being regulated by TFs such as FOS and SPI1, and participating in the cell cycle and cytokine-cytokine receptor interaction pathway.

[Effect of lumbar dorsal muscle injuries on lumbar vertebral bone quality of rat]

Objective: To explored the effects of lumbar dorsal muscle damage on local lumbar vertebral bone quality. Methods: Thirty SD female rats, at age of 20 weeks, were randomly divided into three groups: control group, or say pseudo surgery group, an incision in the back were performed as CNT; bilateral erector spinal muscle group in which group bilateral lumbar erector spinal muscle were removed as RESM; castration group in which bilateral ovaries were resected as OVX.After three months, bone mineral density, microscopic CT and vertebral compression test were taken in lumbar vertebral (L4-6) in turn. Results: After three months bone mineral density in RESM group was obviously lower than the control group [(0.211±0.028) g/cm² vs(0.253±0.021) g/cm², P<0.01], however, there was no significant difference between OVX and RESM[(0.197±0.015) g/cm² vs(0.211±0.028) g/cm², P>0.05]. In microscopic CT three-dimensional reconstruction and bone histomorphometry analysis, compared with control group CNT , in the experimental groups OVX and RESM, bone trabecula of vertebral bodies were more sparse, the overall number and interconnection of trabecula were less.Especially in the OVX, osteoporotic trend of trabecular network trend is more obvious.In vertebral compression test, the maximum load, energy absorption, the maximum stress and elastic modulus in both OVX and RESM were significantly reduced (P<0.01). In the RESM the above four biomechanical parameters were significantly higher than those of OVX (P<0.05). Conclusion: Integrity and vigor of paravertebral muscles would be of great significance to maintain adjacent vertebral bone quality.Resection of lumbar dorsal muscles could lead to a significant decrease of local vertebral bone quality.Damage and atrophy of lumbar dorsal muscle could cause osteoporosis of vertebral bodies.

An extreme internal solitary wave event observed in the northern South China Sea

With characteristics of large amplitude and strong current, internal solitary wave (ISW) is a major hazard to marine engineering and submarine navigation; it also has significant impacts on marine ecosystems and fishery activity. Among the world oceans, ISWs are particular active in the northern South China Sea (SCS). In this spirit, the SCS Internal Wave Experiment has been conducted since March 2010 using subsurface mooring array. Here, we report an extreme ISW captured on 4 December 2013 with a maximum amplitude of 240 m and a peak westward current velocity of 2.55 m/s. To the authors' best knowledge, this is the strongest ISW of the world oceans on record. Full-depth measurements also revealed notable impacts of the extreme ISW on deep-ocean currents and thermal structures. Concurrent mooring measurements near Batan Island showed that the powerful semidiurnal internal tide generation in the Luzon Strait was likely responsible for the occurrence of the extreme ISW event. Based on the HYCOM data-assimilation product, we speculate that the strong stratification around Batan Island related to the strengthening Kuroshio may have contributed to the formation of the extreme ISW.

Diagnostic value of transvaginal color Doppler ultrasound on endometrial lesions

OBJECTIVE

To discuss the diagnostic value of transvaginal color Doppler ultrasound on endometrial lesions.

MATERIALS AND METHODS

The study included 126 cases diagnosed with endometrial lesions by transvaginal color Doppler ultrasound that were examined by hysteroscopy, biopsy, and curettage pathology, and compared with pathology.

RESULTS

The transvaginal color Doppler ultrasound diagnosis corresponded to 92.6% (117 of 126 cases) of the pathology diagnosis.

CONCLUSIONS

Transvaginal color Doppler ultrasound has important diagnostic value in the case of endometrial lesions, has a high rate of detection and diagnostic on endometrial lesions, and is the best method for diagnosis of endometrial lesions.

[A comparison of results between percutaneous transforaminal endoscopic discectomy and fenestration discectomy for lumbar disc herniation in the adolscents]

OBJECTIVE

To compare the preliminary clinical outcomes of percutaneous transforaminal endoscopic discectomy (PTED) and fenestration discectomy (FD) for lumbar disc herniation in the adolscents and further to summarize the clinical experience.

METHODS

The data of 56 patients with single segment lumbar disc herniation who were adopted by our department from January 2011 to December 2013 were retrospectively studied. All patients were divided into 2 groups, including 30 patients undergoing PTED and 26 patients undergoing FD respectively. The factors including the length of skin incision, amount of intraoperative bleeding, operation time and duration of hospitalization were compared. Pfirrmann grading system was used for assessment of lumbar disc degeneration preoperatively and 1 year later. The visual analogue scale (VAS), Oswestry Disability Index (ODI) and Japanese Orthopedic Association (JOA) scores were used to measure the clinical outcomes.

RESULTS

There were significant differences in the observation factors such as the skin incision length, amount of intraoperative bleeding, operation time and duration of hospitalization between the PTED and FD groups (P < 0.05). After surgery, the patients in both groups were followed up for 12 months on average respectively. The postoperative lumbar disc degeneration in PTED group was decreased than that of in FD group. The postoperative VAS scores, ODI and JOA scores at each follow-up time point in both groups were significantly improved when compared with the preoperative ones (P < 0.05). There were no statistically significant differences between the 2 groups in the JOA score improvement rate (P > 0.05). According to 'the modified MacNab criteria, there were no statistically significant differences between the 2 groups in the excellent and good rate (P > 0.05).

CONCLUSIONS

The preliminary clinical efficacy of both PTED and FD in the treatment of single segment lumbar disc herniation in the adolscents is satisfactory. However, PTED is a better minimally invasive surgical method with such advantages as less trauma, less blood loss, early function recovery, less effect on lumbar spinal stability and so on. The short-term outcomes of PTED are similar to that of FD.

IL-1β promotes ADAMTS enzyme-mediated aggrecan degradation through NF-κB in human intervertebral disc

Background

The purpose of this study is to investigate IL-1β regulation of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS-4 and ADAMTS-5) expression through nuclear factor kappa B (NF-κB) in human nucleus pulposus (NP) cells.

Methods

qRT-PCR and Western blot were used to measure ADAMTS expression. Transfections and gene silencing were used to determine the role of NF-κB on cytokine-mediated ADAMTS expression and its role in aggrecan degradation.

Results

IL-1β increased ADAMTS expression in NP cells. Treatment with NF-κB inhibitors abolished the inductive effect of the cytokines on ADAMTS expression. Silencing of p65 confirmed their role in IL-1β-dependent ADAMTS-4 and ADAMTS-5 expression and aggrecan degradation.

Conclusions

By controlling the activation of NF-κB signaling, IL-1β modulates the expression of ADAMTS in NP cells. To our knowledge, this is the first study that shows the contribution of both ADAMTS-4 and ADAMTS-5 to aggrecan degradation in human NP cells.

Impact of ischemic preconditioning on ischemia-reperfusion injury of the rat sciatic nerve

The aim of this study was to assess the preventive effects of ischemic preconditioning (IPC) on ischemia-reperfusion (IR) injury in the sciatic nerve of the rat hind limb. This study included two experiments. For Experiment 1, 40 Sprague-Dawley (SD) rats were randomly divided into 4 equal groups that received different IPC treatments prior to IR. Serum concentrations of aspartate aminotransferase (AST), lactate dehydrogenase (LDH), malondialdehyde (MDA), and superoxide dismutase (SOD) were assessed following reperfusion. Furthermore, we tested the electrophysiological response and ultrastructural changes in the ipsilateral sciatic nerve after IR. After determining the best IPC protocol for protection, we performed a second experiment with 30 SD rats randomly divided into 3 equal groups. Each group underwent 1, 2, or 3 IPC cycles before prolonged ischemia and reperfusion. The same analyses as in Experiment 1 were performed. In Experiment 1, the AST, LDH, and MDA concentrations were decreased in all IPC groups compared with the control group. Concentration of these enzymes showed decreases with increasing IPC cycle number in Experiment 2; however, the difference between 2 and 3 cycles of IPC did not reach significance. Conversely, SOD activity increased in the rapid and delayed groups, and with increasing cycles of IPC. The electrophysiological test showed a decrease in amplitude and increase in conduction velocity with increasing IPC cycles. Moreover, ultrastructural damage decreased with increasing IPC cycles. IPC protected against IR injury in the peripheral nerves. This effect was positively correlated with the number of IPC cycles.

[Comparison of minimally invasive using a tubular retraction system versus open transforaminal lumbar interbody fusion for the treatment of lumbar degenerative diseases]

OBJECTIVE

To compare the clinical effect of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) using a tubular retraction system with traditional transforaminal lumbar interbody fusion (TLIF) for the treatment of lumbar degenerative diseases.

METHOD

From June 2009 to June 2013, a total of 96 patients in Department of Orthopaedics, Armed Police Jiangxi Corps Hospital, suffering from lumbar degenerative diseases were divided into 2 groups randomly. 42 patients underwent MIS-TLIF using a tubular retraction system. There were 23 males and 19 females with the age of 64.4 ± 4.9. The preoperative diagnosis included lumbar disc herniation with instability (17 cases), lumbar spinal stenosis (13 cases), lumbar degenerative spondylolisthesis (12 cases). 54 patients underwent traditional TLIF. There were 32 males and 22 females with the age of 66.5 ± 7.6. The preoperative diagnosis included lumbar disc herniation with instability (22 cases), lumbar spinal stenosis (17 cases), lumbar degenerative spondylolisthesis (15 cases). The general data, operating time, blood loss and volume of drainage after operation were compared between two groups. VAS, ODI evaluating standards were applied to evaluate the therapeutic effect. The intervertebral fusion were observed by X ray or CT scan.

RESULTS

All patients underwent surgery safely without severe complication occurred. There was no significant difference in operation time between MIS-TLIF group (96±37) min and TLIF group (83 ± 25) min, P>0.05; the blood, volume of drainage after operation in MIS-TLIF group were significantly less than TLIF group (P<0.05). The follow-up time was( 26 ± 7) months in MIS-TLIF group and (27 ± 8) months in TLIF group. Compared with preoperative parameters, the scores of VAS and ODI were significantly decreased after surgery and at the final follow-up in both groups (P<0.05). Compared with TLIF group, VAS in MIS-TLIF group of post-operation and the final follow-up were improved, respectively (P<0.05), but there is no significant difference in ODI score. There occurred cage dislocation with no nerve symptom in MIS-TLIF group in 1 case and fat liquefaction in TLIF group in 1 case. At the follow-up after 6.5 months postoperatively, all the operated segments achieved fusion standard and no internal screw were loose or broken.

CONCLUSION

MIS-TLIF technique could provide less operation trauma, blood lose and achieve the similar satisfied short-term effect as traditional TLIF.

Two-dimensional longitudinal strains and torsion analysis to assess the protective effects of ischemic postconditioning on myocardial function: a speckle tracking echocardiography study in rabbits

The reperfusion injury that occurs in the early reperfusion often results in myocardial dysfunction. This study evaluated global and regional left ventricular (LV) function using speckle tracking echocardiography (STE) in a rabbit ischemia-reperfusion (I/R) model with and without ischemic postconditioning (I-PostC). The aim is to investigate the potential benefit of I-PostC for myocardial function and validate whether regional longitudinal strain is an appropriate index to indicate myocardial dysfunction. Forty rabbits were divided into an ischemia-reperfusion group (group I) and an I-PostC group (group II). After the coronary arteries were ligated, LV systolic strain and twist parameters decreased, and absolute value of strain rate of isovolumetric relaxation period (SRivr) and post-systolic strain index (PSI) increased significantly in both groups (all p<0.05). After reperfusion, regional longitudinal systolic strain rate (SRsys), systolic strain (Ssys), LV twist and untwisting rate increased, and SRivr and PSI decreased in group II. These changes were not seen in group I. All STE parameters were correlated with area of necrosis (AN)/area at risk (AR) (all p<0.05). The correlations were morerelevant between SRsys and AN/AR (r=-0.673) and between Ssys and AN/AR (r=-0.777) (both p<0.001). The intra- and inter-observer repeatability of STE parameters were good with correlation coefficients (CCs) >0.8 or 0.6. The sensitivities of GSRsys, GSsys, SRsys, Ssys, and LV twist to detect the myocardial infarction were 81.3%, 62.5%, 87.5%, 93.8% and 81.3%, respectively. And the specificities of those parameters were 75.0%, 81.2%, 75.0%, 87.5% and 68.7%. These results indicate that STE is useful for quantitative detection on myocardial function improvement induced by I-PostC in a rabbit I/R model. The regional index-Ssys is an appropriate parameter to indicate myocardial dysfunction because of its sensitivity, specificity, and repeatability.