BACKGROUND: Histomorphological change of endplate may affect the nntritional transmission of intervertebral disk, eventually leading to intervertebral disc degeneration. OBJECTIVE: To observe the effects of endplate concavity variation on mechanical response of lumbar motion segment. DESIGN, TIME AND SETTING: Repeated measurement design, biomechanical analysis of finite element models, performed at the Laboratory of Biomechanics, Department of Orthopedics, the Second Affiliated Hospital of Medical College of Zhejiang University between January 2005 and January 2007. MATERIALS: SOMATOM SENSATION 16 spiral CT machine (Siemens, German) and ANSYS (Inc. Pennsylvania, USA).METHODS: A three-dimensional nonlinear geometrical and mechanical accurate finite element model of lumbar L<,4-5> segment was developed. Parametric studies were undertaken by studying endplate of three different concave angles, whereas disc angle, the gap of facet joint, finite element mesh density, and all other parameters were kept constant. Biomechanical parameters of three kinds of finite element models were tested under 5 different loading conditions, including vertical compression, flexion, extension, and anterior and posterior shearing loading. MAIN OUTCOME MEASURES: Endplate-intervertebral disc interface strain, intervertebral disc stiffness, nucleus pulposus pressure, annular fiber stress, radial disc bulge, stress in the annulus ground substance, stresses in posterior structure and facet contact force. RESULTS: The decrease in the endplate concavity stimulated by an increasing endplate concave angle would result in decreased strains of endplate-intervertebral disc interface, increased disc stiffness and nucleus pulposus pressure, decreased annular fiber stress, radial disc bulge and stress in the annulus ground substance, and simultaneously produce decreased facet contact force and stresses in posterior structure. CONCLUSION: The decrease of endplate concavity enhances the protective effects of the disc on vertebral body breakage. Small endplate deformation results from decreased endplate concavity would contribute to the reduction of nutritional diffusion to the intervertebral disc.

[Objective] The efleet of sagittal orientations of articular facet on the contact force and contact regions of a lumbar spine segment was evaluated.[Methods] [Results]Three-dimensional geometrical and mechanical accurate finite element models of the lumbar L4、5 motion segment representing three sagittal-orientations articular facet were generated and invalidated by an effective CAD method.Contact force and contact regions of the articular facets of three finite element models were predicted under the pure shearing loads.[Result] Under anterior shear condition,the contact force on the facet decreased with the increase of sagittal 0rientation of articular facet.however.in posterior shear load,the contact force on the facet increased with the increase of sagittal orientation.Meanwhile,under both pure shear loading,the percentages of the sagittal and the transversal components are increased with the dectease of the sagittal angle.However,under the salne load condition,there are no difference between the contact regions of the three models with different facet joint angle.[Conclusion]The spatial orientation and geometric forms of the coronal facet articular surfaces are more effective in restricting motion in transversal and sagittal planes while assuming a minor role in resisting axial force or motion than sagittal facet articular surface.It Was presumed that anterior shear force play a more prominent contribution on the degeneration of the facet joint with coronal articular surface compared with posterior shear force.

AIM:To investigate the inhibitory effect of aliskiren on the angiogenesis of human umbilical vein endothelial cells ( HUVECs) induced by lipopolysaccharide ( LPS) and to explore its possible mechanism.METHODS:HUVECs were cultured and randomly divided into blank group and renin group.The levels of tumor necrosis factor-α(TNF-α) and intercellular adhesion molecule-1 (ICAM-1) in the culture supernatant were detected by ELISA.The protein levels of Toll-like receptor 4 ( TLR4) and ICAM-1 in the HUVECs were determined by Western blot.HUVECs were cul-tured and randomly divided into control group, LPS group, low-dose (1μmol/L) aliskiren group, middle-dose (10μmol/L) aliskiren group and high-dose (100 μmol/L) aliskiren group.The proliferation of HUVECs was detected by MTT and BrdU assays.The mobility of HUVECs was measured by Transwell assay.The formation of the vessels was judged by ob-serving the formation of the luminal structure by HUVECs in Matrigel.The levels of TNF-α, ICAM-1 and monocyte chemo-tactic protein 1 ( MCP-1) in the culture supernatant were measured by ELISA.The expression of renin, TLR4, matrix me-talloproteinases-2 (MMP-2) and matrix metalloproteinases-9 (MMP-9) at mRNA and protein levels in the HUVECs was determined by RT-PCR and Western blot.RESULTS:Renin stimulated the expression of inflammatory factors and TLR4 in the HUVECs.Aliskiren inhibited the growth, migration and angiogenesis of HUVECs in a dose-dependent manner, de-creased the levels of TNF-α, ICAM-1 and MCP-1 and the expression of renin, MMP-2 and MMP-9, and inhibited TLR4 expression (P<0.05).CONCLUSION:Aliskiren inhibits LPS-induced angiogenesis of HUVECs, which may be related to the down-regulation of renin expression, the inhibition of TLR4-mediated inflammatory reaction, and the formation of MMP-9 and MMP-2.

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

Objective To research the connection between the sagittal orientation of facet joints and disc degeneration in lumbar spine and to investigate the contribution of which to development the degenerative spondylolisthesis. Methods A new effective CAD method was used to accurately establish 9 finite element models(FEM)which were assembled respectively with facet-joint angle 65?, 45?, 25?, with normal disc, light degenerative disc and severe degenerative disc. The biomechanical parameters of 9 finite element models were measured under axial compressive load within physiological range. Results Compared with FEMs with facet-joint angle 45? and 25?, anterior displacement of L4 vertebra in FEMs with facet-joint angle 65? was increased, where the maximum von Mises stresses on facet surface, isthmus and the contact force on facet surface in horizontal orientation were obviously increased. Meanwhile, FEMs with facet-joint angle 65? showed a decrease in end-plate bulge and an increase in stress of annular matrix. The stiffness in light degenerative disc FEMs was reduced and the von Mises stresses on facet surface and isthmus was slightly increased compared with the normal disc FEMs. Among all, the FEM with facet-joint angle 65? combined with light degenerative disc showed the poorest resisting anterior shear force. Conclusion Sagittal orientation of facet joints is not only the primary inducement of the degenerative spondylolisthesis but the secondary pathological change of remodeling of the facet-joints induced by the regional stress change. The inherent instability of lumbar motion segment of sagittal orientation of facet joints is influenced by the lumbar disc degeneration. The lumbar disc degeneration has no manifested contribution to the aggravation of the sagittal orientation of facet joints.

Based on the investigation of the rehabilitation demand of disabled persons and the functional advantage of existing health care and services network in Heilongjiang provincial reclamation area, a structural design of community-based rehabilitation development has been drawn out, which including integrating existing three-level health care network, applying appropriate rehabilitation techniques, to establish a convenient, effective, and economical community-based rehabilitation system.

AIM: This study aimed at investigating the effects and mechanism of total alkaloids from Rhizoma Coptidis (TA) on ethanol-induced gastric mucosal injury in rats. METHODS: The experimental gastric damages were established by intragastric ethanol, and the protective effects of TA were evaluated by calculating lesion indices contents and superoxide dismutase (SOD) activity from rat gastric mucosa were measured to explore the interrelation between therapeutic effects of TA and these factors. The expressions of neuronal nitrogen monoxide synthase (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS)from ethanol-damaged gastric mucosa in rats were analysised using immunohistochemical method. RESULTS: TA significantly inhibited the gastric injury induced by ethanol ,in dose-dependent manner,and the effect of TA was superior to that of Berberine (Ber). TA obviously antric mucosa. TA significantly suppressed ethanol-induced decreasing nNOS and eNOS expression and elevation of iNOS expression in rat gastric mucosa. CONCLUSION: Rhizoma Coptidis is a potent candidate in therapeutic drugs of human alcohol-induced gastric injury. Its anti-injury effects involve in Ber and other ingredients of TA. The protective mechanisms of TA involve in inhibiting generation of oxygen-derived free radical, accelerating scavenging of free radicals, relieving lipid peroxidation, and maintaining NO content in normal level by inhibiting decreasing of nNOS and eNOS expression and elevation of iNOS expression.

Objective To optimize the antibacterial drug regimen in ICU common staphylococcal infection.Methods The pharmacokinetic and pharmacodynamic parameters of antibacterial drugs were collected in combination with the hospital ICU anti-microbial drug resistance monitoring reports from the national antimicrobial resistance investigation net (Mohnarin)of the Ministry of Health and the performance standards for antimicrobial susceptibility testing (2013)issued by the clinical and laboratory stand-ards institute (CLSI),the minimum inhibitory concentration (MIC)of staphylococci was set by using the discrete uniform distribu-tion method and 16 kinds of administration regimens with 6 antimicrobial agents were worked out.The best initially antimicrobial regimen was optimized by using the pharmacokinetic and pharmacodynamic models and Monte Carlo simulations of cumulative frac-tion of response (CFR)from 5 000 patients.Results The alternative initially drug regimens to the infectious bacteria were:linezolid 0.40 g twice daily and vancomycin 0.75 g twice daily for staphylococcus aureus;amikacin 0.60 g once daily and linezolid 0.40 g twice daily,and vancomycin 0.75 g twice daily for hemolytic staphylococci and staphylococcus epidermidis;linezolid 0.40 g twice daily and vancomycin 0.75 g twice daily for methicillin-resistant Staphylococcus aureus;ampicillin/sulbactam 1.50 g 4 times daily, cefuroxime 0.75 g 4 times daily,amikacin 0.60 g once daily,moxifloxacin 0.40 g once daily for methicillin-sensitive staphylococcus aureus.Conclusion In the Staphylococcus aureus infection occurred in ICU,if which being methicillin-sensitive could be deter-mined,ampicillin/sulbactam,cefuroxime,amikacin and moxifloxacin could be selected for treatment,and linezolid or vancomycin could be selected for treating possible methicillin-resistant Staphylococcus aureus infection or undetermined whether being methicil-lin-resistant Staphylococcus aureus infection.

Objective To investigate the relationship between circulating tumor cells(CTCs) in peripher-al blood and the prognosis of pancreatic cancer patients. Method From Mar 2010 to Mar 2015, patients with pancreatic cancer in guangzhou first people′s hospital were enrolled in this study. Immunomagetic negative en-richhment together with immunofluorescence were used to identify CTCs. The clinical data of all patients were analyzed. Result No CTCs were found in peripheral blood of healthy control cases. The detection date of CTCs was 60.0%. The positive rate of CTCs was closely correlated with cell differentiation and the clinical stage. Con clusion CTCs count in old patients with pancreatic cancer can reflect the status of the patients and is help-ful for the diagnosis of micrometastasis , re-determination of the clinical stage and the guidance of patients′s treatment. CTCs count can predict the survival time of elderly patients with pancreatic cancer.