Phosphine-functionalized amidinate ligated rare-earth metal complexes for highly 3,4-selective living polymerization of 1,3-conjugated dienes.

A series of rare-earth metal bis(alkyl) complexes have been prepared via protonolysis reactions of tris(aminobenzyl) complexes (Ln(CH2C6H4N(Me)2-o)3) with phosphine-functionalized amidinated ligands (DippNCN(CH2)nPPh2, n = 2 (L1-H) and n = 3 (L2-H)). The X-ray diffraction of P2-Sc (DippNCN(CH2)3PPh2Sc(CH2C6H4N(Me)2-o)2) showed the un-coordination of the diphenylphosphine group due to the inherent saturation of the central metal ion. In conjunction with [Ph3C][B(C6F5)4], all the rare-earth metal complexes showed a high catalytic activity for the polymerization of 1,3-conjugated dienes (isoprene, ß-myrcene and ß-farnesene), affording highly 3,4-regular polymers (up to 100% 3,4-) with high molecular weight and narrow molecular weight distribution. After the abstraction of the alkyl moiety -CH2C6H4N(Me)2-o of P1-Sc by [Ph3C][B(C6F5)4], the species with the coordination of the diphenylphosphine group to the central metal probably formed, as shown in the 31P NMR spectra and DFT calculation results, and it might serve as the true active species in the 3,4-selective polymerization of 1,3-conjugated dienes.

Access to Derivatizable Octahydrofluorenyl Ligand: Half-Sandwich Rare-Earth Metal Complexes for Highly Syndiospecific (Co)Polymerization of Styrene.

A simple and facile synthetic pathway for accessing new derivatizable bulky-demanding octahydrofluorenyl (OHF) ligands has been developed, and a series of half-sandwich rare-earth metal (Sc, Y, Lu) complexes bearing the OHF ancillary ligands have been synthesized. In conjunction with a borate, the OHF-ligated Sc complexes exhibited high catalytic activity for styrene (co)polymerization to afford polymers with highly syndiotactic polystyrene sequence (>99% rrrr).

Combined use of calcium phosphate cement, mesenchymal stem cells and platelet-rich plasma for bone regeneration in critical-size defect of the femoral condyle in mini-pigs.

Aim: To investigate the outcome of autologous bone marrow mesenchymal stem cells (BMMSCs) and platelet-rich plasma in combination with calcium phosphate cement (CPC) scaffold to reconstruct femoral critical bone defects in mini-pigs. Materials & methods: Scanning electron microscopy, micro-computed tomography evaluation and quantitative histological assessment were used. Results & conclusion: BMMSCs were attached to the CPC scaffold after 7 days of culture and decreased the residual CPC material in each group at 12 weeks compared with 6 weeks. The newly formed bone area was higher in the CPC+SC+P group than in the CPC group at each time point (all p < 0.05). The strategy of CPC combined with BMMSCs and platelet-rich plasma might be an effective method to repair bone defects.

Endoplasmic reticulum stress regulates cell injury in lipopolysaccharide-induced nerve cells.

OBJECTIVE: Sepsis-associated encephalopathy (SAE) is a common complication of sepsis, and excessive endoplasmic reticulum (ER) stress is closely correlated with the cell injury caused by sepsis. This study aimed to analyze the possible role of ER stress in SAE cell models. METHODS: PC12 and MES23.5 cells were treated with increasing concentrations of lipopolysaccharides (LPS). The Cell Counting Kit-8 assay was used to detect cell viability and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was performed to assess cell apoptosis. In addition, the protein expression levels of ER stress markers [GRP78, CHOP, inositol-requiring enzyme 1 (IRE1), and PKR-like ER kinase (PERK)] and apoptosis-related proteins (Bax, Bcl-2, caspase-3, and cleaved caspase-3) were analyzed using western blotting. RESULTS: LPS treatment activated ER stress markers in both the PC12 and MES23.5 cells. The overexpression of GRP78 significantly reduced cell viability and enhanced cell apoptosis in a time-dependent manner. An ER stress inhibitor, 4-PBA, significantly enhanced cell viability and inhibited the cell apoptosis induced by LPS. Therefore, an enhanced unfolded protein response (UPR) and UPR suppression may regulate cell apoptosis. CONCLUSIONS: UPR was shown to be involved in regulating LPS-induced neuron injury. UPR could be a potential therapeutic target in SAE.

A Modified Percutaneous Endoscopic Technique to Remove Extraforaminal Disk Herniation at the L5-S1 Segment.

OBJECTIVE: To introduce a modified percutaneous endoscopic lumbar diskectomy (PELD) technique to remove extraforaminal disk herniation at the L5-S1 segment, including the technical essentials and preliminary results. METHODS: The geometric parameters of the transverse process, facet joint, and sacrum (TFS) space based on imaging examination were measured in 100 common patients. The technical essentials, including working cannula placement and disk removal involved in the technique, were described. Ten cases (7 men and 3 women) with extraforaminal disk herniation at L5-S1 were surgically treated with the PELD technique through the TFS space from June 2015 to March 2017. RESULTS: The maximum diameter of the TFS space varied from 2.73 to 11.81 mm (6.84 ± 2.01 mm) on the left and 3.00 to 10.47 mm (7.02 ± 2.05 mm) on the right. The distance of possible skin entry points from midline varied from 33.28 to 84.18 mm, and the distance of external iliac vessels to skin varied from 70.05 to 119.14 mm. All 10 patients who underwent the modified PELD technique were back to previous activities in 1 month. Visual analog scale (VAS) or Oswestry Disability Index (ODI) scores reduced to 2.5 ± 2.0 or 25.4 ± 10.8 from 7.5 ± 1.3 or 75.2 ± 13.3, respectively, 1 day after operation. At 30 days after the operation, the VAS score was 1.0 ± 0.6 and ODI score was 10.2 ± 3.2. No neurologic deficit or surgical site infection occurred. CONCLUSIONS: We introduced a modified PELD technique to remove extraforaminal disk herniation at the L5-S1 segment. This technique was less invasive, effective, and safe. We also summarized a detailed protocol to identify and remove the herniated disk for nerve protection.

Is Short Same-Segment Fixation Really Better than Short-Segment Posterior Fixation in the Treatment of Thoracolumbar Fractures?

STUDY DESIGN: A retrospective study. OBJECTIVE: This retrospective study assessed whether short same-segment fixation (SSSF) is better than short-segment posterior fixation (SSPF) for reducing thoracolumbar fractures, improving the kyphosis angle, maintaining vertebral height, or reducing the incidence of broken screws. SUMMARY OF BACKGROUND DATA: In clinical practice, single-segment thoracolumbar fractures were then more likely to be treated with SSPF that included pedicle fixation at the level of the fracture (short same-segment fixation, or SSSF). Whether SSSF could really achieve vertebral height recovery, improve the kyphosis, reduce postoperative kyphosis loss, and reduce the incidence of internal fixation failure better than SSPF. METHODS: Patients treated with SSPF or SSSF at our institution during 2006 to 2014 were reviewed. Effects of thoracolumbar fracture reduction, improved kyphosis angle, and maintaining vertebral height were compared between groups. Logistic regression analysis was used to identify factors related to instrumentation breakage and correlation analysis to assess possible relations between loss of correction of the kyphosis angle (LAWAC) and other factors. RESULTS: Altogether, 130 patients were enrolled (53 SSPF, 77 SSSF). SSPF (22F, 31M) group's mean (range) age was 37.7 (16-60) years, and the follow-up was 26.2 (9-120) months. SSSF (27F, 50M) group's mean (range) age was 39.3 (17-61) years, and the follow-up was 23.2 (9-60) months. All patients underwent either internal fixation or screw repair. Immediately postoperatively, restoration after middle vertebral fractures was better in SSSF patients than in SSPF patients (P = 0.003), with no differences in other fracture-related factors (P > 0.05). Only LAWAC was significantly associated with instrumentation breakage (P < 0.05). Also, immediately postoperatively, the anterior/posterior vertebral heights ratio was negatively related to LAWAC. CONCLUSION: Pedicle fixation of the fracture did not obtain better recovery of anterior or posterior vertebral heights nor did it improve AWA restoration. There was no significant difference in LAWAC between groups or in the incidence of broken screws. LAWAC may increase the incidence of broken screws. LEVEL OF EVIDENCE: 4.

Bone regeneration in minipigs via calcium phosphate cement scaffold delivering autologous bone marrow mesenchymal stem cells and platelet-rich plasma.

Macroporous calcium phosphate cement (CPC) with stem cell seeding is promising for bone regeneration. The objective of this study was to investigate the effects of co-delivering autologous bone marrow mesenchymal stem cells (BMSCs) and autologous platelet-rich plasma (PRP) in CPC scaffold for bone regeneration in minipigs for the first time. Twelve female adult Tibet minipigs (12-18 months old) were used. A cylindrical defect with 10 mm height and 8 mm diameter was prepared at the femoral condyle. Two bone defects were created in each minipig, one at each side of the femoral condyle. Three constructs were tested: (1) CPC scaffold (CPC control); (2) CPC seeded with BMSCs (CPC-BMSC); (3) CPC seeded with BMSCs and PRP (CPC-BMSC-PRP). Two time points were tested: 6 and 12 weeks (n = 4). Good integration of implant with surrounding tissues was observed in all groups. At 12 weeks, the CPC-BMSC-PRP group had significantly less residual CPC remaining in the defect than the CPC-BMSC group and the CPC control (p < 0.05). The residual CPC volume for the CPC-BMSC-PRP group was half that of the CPC control. New bone formation for CPC-BMSC-PRP was more than two-fold that of the CPC control (p < 0.05). CPC-BMSC-PRP had new blood vessel density that was nearly two-fold that of the CPC control (p < 0.05). In conclusion, CPC scaffold with autologous BMSC-PRP doubled the new bone regeneration and blood vessel density in minipigs compared with the CPC control. In the present study, the new macroporous CPC system with co-delivered BMSC-PRP has been shown to promote scaffold resorption and bone regeneration in large defects. Copyright © 2017 John Wiley & Sons, Ltd.

The Effects of Orientation of Lumbar Facet Joints on the Facet Joint Contact Forces: An In Vitro Biomechanical Study.

STUDY DESIGN: A biomechanical human cadaveric study. OBJECTIVE: The aim of this study was to measure L2-L3 facet joint contact forces in a flexibility test using thin film electroresistive sensors, and facet joint orientation on computed tomographic (CT) scan images, to examine the effects of orientation of lumbar facet joint on the facet joint contact forces. SUMMARY OF BACKGROUND DATA: Biomechanically, the bilateral facet joints play a critical role in maintaining stability of the lumbar spine. The effect of orientation of lumbar facet joints on the contact forces remains unknown. METHODS: Eight human cadaveric lumbar spine specimens (L2-L3) were tested by applying a pure moment of ±7.5 Nm in three directions of loading (flexion-extension, lateral bending, and axial rotation) with and without a follower preload of 300 N. The orientation of the lumbar facet joints at the L2-L3 was measured on axial CT scans. Bilateral facet contact forces were measured during flexibility tests using thin film electroresistive sensors (Tekscan 6900). RESULTS: The average total peak facet loads was 66 N in axial rotation, 27 N in extension, and 20 N in lateral bending under a pure moment. Under a pure moment with a follower preload of 300 N, the average total peak facet loads was 53 N in axial rotation, 43 N in extension, and 24 N in lateral bending. The facet joint forces were correlated positively and significantly with the orientation in all directions with and without a compressive follower preload (P < 0.05). In addition, the facet joint contact forces at neutral position with a follower preload were correlated positively with the orientation (rs = 0.759, P = 0.001). CONCLUSION: This study identified that the greater coronal orientation of lumbar facet joints is, the higher the facet joint contact forces are. LEVEL OF EVIDENCE: 3.

Facet Sagittal Orientation: Possible Role in the Pathology of Degenerative Lumbar Spinal Stenosis.

STUDY DESIGN: A retrospective case-control study. OBJECTIVE: This study aimed to elucidate the association between facet joint orientation and degenerative lumbar spinal stenosis (DLSS). SUMMARY OF BACKGROUND DATA: Many studies have demonstrated the relationship between sagittal facet orientation and degenerative lumbar spondylolisthesis. However, the associations between facet orientation and DLSS have rarely been studied. METHODS: Ninety-one age-matched and sex-matched patients with DLSS (LSS group) and 91 control participants were consecutively enrolled. Their lumbar facet angles and the dural sac cross-sectional area at L2-L3, L3-L4, L4-L5, and L5-S1 were measured using axial magnetic resonance imaging. The intersection angle of the midsagittal line of the vertebra to the facet line represents the orientation of the facet joint. RESULTS: The facet angles on the left side or right side of the LSS group were significantly smaller than the respective ones of the control group. Outcomes of the groups revealed significantly and consistently increasing facet angles from L2-L3 to L5-S1. The dural sac cross-sectional area of the LSS group had significantly smaller measurements values than that of the control group at L2-L3, L3-L4, L4-L5, and L5-S1. CONCLUSION: Sagittalization of lumbar facet joints was considered to be a risk factor for DLSS and may play a role in the pathology of DLSS. LEVEL OF EVIDENCE: 3.

[Delayed decompression for cauda equina syndrome secondary to lumbar disc herniation: long-term follow-up results].

OBJECTIVE: To assess the impact of delayed decompression on long-term neurological and bladder function recovery in patients with cauda equina syndrome (CES) secondary to lumbar disc herniation (LDH). METHODS: The clinical data of 35 patients receiving delayed decompression surgery for CES secondary to LDH were reviewed. The bladder empty function, bowel control, sexual ability and neurological functions of the lower limbs were evaluated after the operation, and the urodynamic changes were assessed in 6 patients with urodynamic data before and after the operation. RESULTS: Surgical decompression was performed at 4.1∓3.9 weeks in 12 patients with complete CES and at 5.5∓7.6 weeks in 23 patients with incomplete CES after the onset of symptoms. The patients were followed up for a mean of 43.0∓28.9 months (3-110 months). In the 23 patients with incomplete CES, 19 obtained full recovery, 4 had slight sensory alterations in the saddle area or the lower limbs. In the 12 patients with complete CES, 2 had full recovery, 4 reported slight sensory alterations in the saddle area or the lower limbs (including 2 with occasional constipation); 6 still had sense deficit in the saddle area and difficulties in bladder or bowl emptying, but they all reported significant improvements compared to the condition before operation. Urodynamic analysis in the 6 patients with pre- and postoperative urodynamic data showed increased abdominal pressure when voiding with significantly reduced residual urine in all the 6 patients; 4 patients with abnormal first desire volume before operation reported recovery after the operation. CONCLUSION: Patients with LDH-induced CES who missed the chance of early decompression can still expect favorable functional recovery in the long term. The improvement of bladder function following decompression is probably a result of recovery of bladder sensation and the compensation by increased intra-abdominal pressure. The key strategy to promote bladder function recovery in these patients is to promote the detrusor recovery.

Minipig-BMSCs Combined with a Self-Setting Calcium Phosphate Paste for Bone Tissue Engineering.

Calcium phosphate cements (CPCs) are a new generation of bone repair materials with good biocompatibility for various stem cells. The minipig is a recommended large animal model for bone engineering research. This study aimed to evaluate the feasibility of utilizing CPC scaffolds for the adhesion, proliferation, and osteogenic differentiation of minipig's bone marrow mesenchymal stem cells (pBMSCs). Passage 3 pBMSCs were seeded on the CPC scaffold and cultured with osteogenic culture medium (osteogenic group) or normal medium (control group). The density of viable cells increased in both groups, and pBMSCs firmly attached and spread well on the CPC scaffold. The alkaline phosphatase (ALP) activity in the osteogenic group had significantly increased on day 7 (D7) and peaked on D14. qRT-PCR revealed that mRNA levels of ALP and three osteogenic marker genes were significantly higher on D4, D7, and D14 in the osteogenic group. Alizarin Red S staining showed a significantly higher degree of bone mineralization from D7, D14 to D21 in the osteogenic group. These results indicated that pBMSCs can attach, proliferate well on CPC scaffold, and be successfully induced to differentiate into osteogenic cells. Our findings may be helpful for bone tissue engineering and the studies of bone regeneration.

Is duration of preoperative anti-tuberculosis treatment a risk factor for postoperative relapse or non-healing of spinal tuberculosis?

PURPOSE: This study evaluated the relationship between spinal TB postoperative recurrence or non-healing and duration of preoperative anti-TB treatment (ATT). METHODS: From January 2004 to January 2013, patients who underwent surgery for spinal TB and met this study's inclusion criteria were retrospectively reviewed. Observed parameters were age, sex, initial ESR, preoperative ESR, degree of ESR change, initial CRP, preoperative CRP, degree of CRP change, duration of preoperative ATT, surgical approach, presence of internal fixation, location of spinal lesion, number of involved segments, duration of operation, and intraoperative blood loss. The data were analyzed by univariate and multivariate analyses for spinal TB recurrence or non-healing to determine related risk factors. RESULTS: A total of 223 patients met the inclusion criteria. There were 84 female and 139 male patients with a mean age of 42.2 years (range 2-85 years). The follow-up period was 18-72 months (average 28.7 months). Among 223 patients observed, 23 patients had postoperative relapse or non-healing (10.3 %) during the follow-up period. Statistical analysis indicated that the location of a spinal lesion was significantly associated with postoperative relapse or non-healing. Risk of postoperative relapse or non-healing in thoracolumbar TB was 2.524-fold (95 % CI 1.026-6.580) that of lumbosacral TB. CONCLUSIONS: Duration of preoperative ATT may not be a risk factor for postoperative recurrence or non-healing of spinal TB. Junctional zones such as the lumbosacral and thoracolumbar junction have a higher recurrence rate than non junctional.

Clinical outcomes after decompressive laminectomy for symptomatic ossification of ligamentum flavum at the thoracic spine.

Ossification of the ligamentum flavum (OLF) is a rare disease that causes acquired thoracic spinal canal stenosis and thoracic myelopathy. The aim of this study was to investigate clinical outcomes of symptomatic thoracic OLF treated using posterior decompressive laminectomy. We retrospectively analyzed the medical records of 22 patients who underwent posterior decompressive laminectomy for symptomatic thoracic OLF. The surgical results were evaluated using the modified Japanese Orthopaedic Association (JOA) scoring system and Hirabayashi recovery rate. The intensity of pain was evaluated using a visual analog scale (VAS). The mean duration of follow-up was 35.6months. The mean JOA score was significantly improved at final follow-up (9.18±standard deviation of 1.53 points [range, 6-11 points]) compared with before surgery (5.64±2.04 points [range, 3-9 points]) (P<0.001). The mean Hirabayashi recovery rate was 65.49% (range, 20-100%). Recovery outcomes were excellent in nine patients, good in eight patients, fair in four patients and unchanged in one patient. No patient was classified as deteriorated. The VAS scores were 2.82±3.08 before surgery and 0.59±1.05 at final follow-up (P=0.001). Surgical complications, which resolved after appropriate and prompt treatment, included dural tear in five patients, cerebrospinal fluid leakage in one patient, immediate postoperative neurologic deterioration in one patient, epidural hematoma in one patient, and wound infection in one patient. Our findings suggest that posterior decompressive laminectomy is an effective treatment for symptomatic thoracic OLF and provides satisfactory clinical improvement, but surgery for thoracic OLF is associated with a relatively high incidence of complications.

[Establishment of a rabbit model of scoliosis induced by asymmetric load using springs].

OBJECTIVE: To establish rabbit model of scoliosis induced with stable asymmetric lumbar loads. METHODS: Scoliosis was induced in 10 two-month-old New Zealand rabbits using 316L stainless steel springs placed between the unilateral transverse processes of L2 and L5. Serial radiographs were documented before and at 1, 4, 8, 9 and 12 weeks after the operation. At weeks, the rabbits were randomly divided into SR group (n=5) with the spring removed and SK group (n=5) without spring removal. RESULTS: All the rabbits survived the experiment with Cobb angle all greater than 10 degree at the end of the experiment. Significant changes were found in the Cobb angles and kyphotic angles at 1, 4 and 8 weeks after the operation (P<0.05). At 8 weeks, the Cobb angle, the kyphotic angle and the length of the spring were similar between SR and SK groups (P>0.05), and in the 4 weeks following spring removal in SR group, the Cobb angle and the kyphosis decreased significantly compared with those in SK group (P<0.05). Micro-CT showed that the BV/TV of the concave side was greater than that of the convex side. The length of the spring did not show obvious changes during the experiment (P>0.05). CONCLUSIONS: Asymmetric lumbar loading is a convenient, time-saving, and highly reproducible approach for establishing rabbit models of scoliosis.

Risk factors of new symptomatic vertebral compression fractures in osteoporotic patients undergone percutaneous vertebroplasty.

PURPOSE: This study evaluated the risk factors of new vertebral compression fractures (VCFs) following percutaneous vertebroplasty (PVP). METHODS: From June 2005 to January 2011, patients with osteoporotic VCFs (OVCFs) who were treated with PVP and met this study's inclusion criteria were retrospectively reviewed. Observed parameters were age, sex, bone mineral density, body mass index, amount of bone cement, cement leakage into the disk, preoperative kyphosis, preoperative degree of anterior vertebral compression, preoperative degree of middle vertebral compression, kyphosis correction, anterior vertebral height restoration, middle vertebral height restoration, and number of initial symptomatic fractures (levels treated). The data were analyzed by univariate and multivariate analysis for the emergence of new fractures after PVP to determine related risk factors. RESULTS: A total of 182 patients met the inclusion criteria. There were 155 female and 27 male patients with a mean age of 69.7 years (range 49-91 years). The follow-up period was 24-50 months (average 26.4 months). A total of 294 VCFs among 182 patients were observed, 28 new VCFs occurred in 21 patients (21/182, 11.5 %) during the follow-up period. Statistical analysis indicated that higher BMI (P = 0.004) and a greater number of initial symptomatic fractures (P = 0.017) were significantly associated with new VCFs after PVP. It is the most obvious that the risk of new fractures increased 2.518-fold (95 % CI 1.176-5.395), when the number of initial VCFs increased by one level. CONCLUSIONS: The incidence of new symptomatic VCFs after PVP was higher in osteoporotic patients with initial multiple-level fractures.

[Clinical efficacy of unipedicular versus bipedicular percutaneous vertebroplasty for Kummell's disease].

OBJECTIVE: To compare the clinical efficacy and safety of percutaneous vertebroplasty by unipedicular and bipedicular approach for treatment of Kummell's disease. METHODS: The clinical data of patients with Kummell's disease undergoing percutaneous vertebroplasty via unilateral or bilateral approach between January, 2006 and January, 2011 were reviewed. The clinical efficacy, operation time, bone cement injection volume, incidence of cement leakage, degree of vertebral height restoration, and degree of kyphosis correction were compared between the patients receiving surgery via the two approaches. RESULTS: The operation time was shorter in the unipedicular group than in the bipedicular group (P<0.05), but bone cement injection volume, incidence of cement leakage, degree of anterior vertebral height restoration, degree of middle vertebral height restoration, degree of kyphosis correction, and VAS scores were all comparable between the two groups (P>0.05). In both groups, the VAS scores at 24 h, 3 months and at the last follow-up after the surgery were lowered compared to the preoperative scores (P<0.05). CONCLUSION: Both unipedicular and bipedicular percutaneous vertebroplasty can achieve satisfactory analgesia in the treatment of Kummell's disease with similar clinical efficacy. The unipedicular approach is sufficient for treatment of Kummell's disease.

Age-related changes in the orientation of lumbar facet joints.

STUDY DESIGN: A measurement and analysis of the orientation of the lumbar facet joints at the L4-L5 level of different age groups. OBJECTIVE: To explore the correlation between age and orientation of the lumbar facet joints. SUMMARY OF BACKGROUND DATA: Previous studies have shown an association between sagittal orientation of the lumbar facet joints and degenerative spondylolisthesis, however, there is no information available on the association between orientation of the lumbar facet joints and age. This article studied the association between orientation of the lumbar facet joints and age. METHODS: Three hundred spinal disease-free people coming for periodic physical examination during May 2007 and 2008 in our hospital accepted lumbar computed tomography (CT) scanning and were randomly selected. All the subjects were divided into 6 groups based on age (group I: <30 years of age, group II: 31-40 years, group III: 41-50 years, group IV: 51-60 years, group V: 61-70 years, and group VI: >70 years of age). CT scans of the lumbar spine were stored in digitized form for measurement and analysis. The orientation of the lumbar facet joints at the L4-L5 was measured on axial CT scans, and the intersection angle of the midsagittal line of vertebra to the facet line represent the orientation of the facet joint. RESULTS: The angles of the L4-L5 facet joints to the vertebral sagittal plane of group I to VI are 50.61 degrees +/- 6.55 degrees, 47.05 degrees +/- 7.53 degrees, 46.56 degrees +/- 7.38 degrees, 43.39 degrees +/- 6.19 degrees, 40.95 degrees +/- 7.27 degrees, and 39.89 degrees +/- 9.05 degrees, respectively (P = 0.000). CONCLUSION: The coronal orientation of the L4-L5 facet joints was negatively correlated to age (r = -0.456, P = 0.000), which could be one of the explanations that the aging people are prone to degenerative spondylolisthesis.

[Status and application prospect in repair of spinal cord injury by stem cells].

OBJECTIVE: To review the status and application prospect in repair of spinal cord injury by stem cells. METHODS: The related articles in recent years were extensively reviewed, the biological characteristics of stem cells, the experimental and clinical studies on repair of spinal cord injury by stem cells, the mechanism of the therapy and the problem were discussed and analyzed. RESULTS: The foundational and clinical study indicated that the great advance was made in repair of spinal cord injury, the stem cells could immigrate in the spinal cord, and differentiate into neuron and secrete neurotrophic factors. So it could promote the repair effects. CONCLUSION: Repair of spinal cord injury by stem cells is an effective therapy strategy, but many problems remain to be resolved.

Preparation and characterization of bisphenol A-cationized bovine serum albumin.

To detect BPA residue in the environment quickly by immune method, preparation of high quality antibody against BPA was the most critical step of project. Based on Mannich-type reaction and EDC method, we produced BPA-cBSA and BHPVA-BSA against BPA and the conjugates were characterized by UV-Vis and FT-IR spectroscopy. Compared with BSA, cBSA as carrier protein could improve the efficiency of coupling and significantly enhance the immune response against BPA. The mole coupling ratio of BPA-cBSA (8:1) was greater than that of BHPVA-BSA (5:1). We also observed that the similar sensitivity of antisera against BPA between the BPA-cBSA group and BHPVA-BSA group.

[Perioperative complications of single-stage surgical management for spinal tuberculosis].

OBJECTIVE: To analyze the causes of perioperative complications of single-stage surgical management for spinal tuberculosis. METHODS: One hundred and twenty patients with thoracic, lumbar and lumbosacral spinal tuberculosis were treated by single-stage surgical management from January 1997 to January 2006 in our unit, including seventy-five males and forty-five females. The mean age was 34.5 (range 17 to 68) years old. The lesion ranged from T(6) to S(1). The anterior procedures of anterior debridement, interbody fusion and anterior fixation were carried out in sixty-five cases, posterior procedures in twenty-six cases, and combined anterior and posterior procedures in twenty-nine cases, respectively. The complications that occurred during surgical procedure and 1 month after operation were recorded. Underlying causes were analysed. RESULTS: There were 10 cases (8.3%) were recorded of mild to severe complications during perioperative period in 120 patients. The complications and underlying causes were as follows: (1) A patient died from liver failure and blood coagulation dysfunction after operation due to inappropriate surgical timing (n = 1), in which case the patient with lumbosacral spinal tuberculosis also suffered from alcoholic liver sclerosis and dysfunction. (2) False diabetes insipidus (n = 1) and deep vein thrombosis of lower limbs (n = 1) occurred as result of surgical trauma. (3) Tear of iliac vein (n = 1) occurred with lumbosacral spinal tuberculosis because of unclear anatomical relationships when anterior debridement was performed. Injury of lumbar nerve roots (n = 3) and hemothorax (n = 1) also occurred due to mispractice of surgical procedures. (4) Paralysis intestinal obstruction and hypokalemia (n = 2) occurred after anterior procedures for lumbar spinal tuberculosis as a result of other reasons. CONCLUSIONS: Improper perioperative care will lead to complications of single-stage surgical procedures for spinal tuberculosis. Emphasis should be put on preoperative evaluation, surgical planning, and postoperative caring for prevention of complications.