Carbon Nanotube-Doped 3D-Printed Silicone Electrode for Manufacturing Multilayer Porous Plasticized Polyvinyl Chloride Gel Artificial Muscles.

Plasticized polyvinyl chloride (PVC) gel has large deformation under an applied external electrical field and high driving stability in air and is a candidate artificial muscle material for manufacturing a flexible actuator. A porous PVC gel actuator consists of a mesh positive pole, a planar negative pole, and a PVC gel core layer. The current casting method is only suitable for manufacturing simple 2D structures, and it is difficult to produce multilayer porous structures. This study investigated the feasibility of a 3D-printed carbon nanotube-doped silicone electrode for manufacturing multilayer porous PVC gel artificial muscle. Carbon nanotube-doped silicone (CNT-PDMS) composite inks were developed for printing electrode layers of PVC gel artificial muscles. The parameters for the printing plane and mesh electrodes were explored theoretically and experimentally. We produced a CNT-PDMS electrode and PVC gel via integrated printing to manufacture multilayer porous PVC artificial muscle and verified its good performance.

Study on nonlinear dynamic characteristics of a two-speed transmission system at low speed.

A pure shear mechanical model of low gear of six-degree-of-freedom two-speed transmission system is established by using lumped parameter method. The Runge-Kutta method is used to numerically solve the aforementioned nonlinear system. The variation of transmission error between gears is analyzed by using global bifurcation, time domain diagram, phase diagram and Poincare cross section. Moreover, the transfer error bifurcation characteristics of the solar wheel and the first planetary wheel under different gear moduli are investigated. The results show that: by taking the excitation frequency as the control parameter, the system includes period-1 motion, period-2 motion, quasi-periodic motion, multiperiodic motion, and chaotic motion. With the increase of gear modulus, the system mainly presents chaotic motion in the medium frequency range (0.5<ωh≤2). It shows stable period-1 motion in the high frequency range (2<ωh≤3), and the higher the modulus, the wider the high frequency range of period-1 motion. The research results can provide reference for the design and optimization of this kind of two-speed transmission system in the future.

Transforaminal percutaneous endoscopic discectomy for symptomatic gas-filled discal cysts-report of three cases and literature review.

OBJECTIVE: The aim of this retrospective study is to review our experience in the diagnosis and role of transforaminal percutaneous endoscopic discectomy (TPED) for symptomatic gas-filled discal cysts. METHODS: Between May 2014 and June 2017, 3 patients from Lishui Center Hospital (Lishui China), who underwent TPED for symptomatic gas-filled discal cysts, were analyzed. The clinical features, imaging findings, operative findings, and treatment outcomes are presented. In addition, relevant literature regarding gas-filled discal cysts was searched using PubMed, and their characteristics, clinical features, therapeutic strategies, and survival outcomes were reviewed. RESULTS: The median age of the patients was 56.7 years (range, 55-60 years). In all patients, a discal cyst was located in the lumbar region, and the patients presented with backache and numbness in the lower extremities. The diagnosis was made by lumbar 3-dimensional computed tomography (3D-CT) or magnetic resonance imaging (MRI). All patients underwent TPED. All patients recovered successfully and were eventually discharged. Eighteen articles were identified from the searches of the database, and a total of 42 patients were included. There were 28 males and 14 females. The mean age was 56.8 years, ranging from 27 to 85 years. Lower back pain was the major symptom. Twenty-two patients underwent surgery, 4 patients underwent percutaneous needle aspiration, 2 patients underwent drug therapy, 13 patients received nonoperative treatment, and 1 patient was unknown. CONCLUSION: TPED for gas-filled discal cysts is feasible, effective, and successful, although it should be performed by an experienced surgeon with awareness of the potential risk of severe nerve root injury.

Successful medical drainage and surgical treatment for vertebral osteomyelitis and bilateral psoas abscess with gas formation caused by klebsiella pneumoniae in a diabetic patient.

OBJECTIVE: We describe the case of a diabetic patient who developed vertebral osteomyelitis and bilateral psoas abscess with gas formation due to klebsiella pneumoniae. METHODS: A 64-year-old woman with a 4-year history of type-2 diabetes mellitus was admitted to the Emergency Department. The subject had a 2-day history of high-grade fever associated with chills and a 5-hour history of consciousness. She received empirical treatment with febrifuge, after which her fever decreased. RESULTS: Her fever recurred after an interval of three hours. A computed tomography scan of the abdomen revealed vertebral osteomyelitis and bilateral psoas muscle abscess with gas formation. Blood culture and purulent fluid described the growth of the Klebsiella pneumoniae. The patient received antibiotic therapy and bilateral drainage therapy after the drainage catheter was placed into the abscess cavity by CT-guidance. Due to the serious damage to the vertebral column and permanent pain, the patient underwent minimally invasive internal spinal fixation and recovered successfully. CONCLUSION: A case of vertebral osteomyelitis and bilateral psoas abscess with gas formation caused by Klebsiella pneumoniae in a diabetic patient. Antibiotic therapy, drainage, and minimally invasive internal spinal fixation were performed, which enabled a good outcome.

Successful medical drainage and surgical treatment for vertebral osteomyelitis and bilateral psoas abscess with gas formation caused by klebsiella pneumoniae in a diabetic patient

SUMMARY OBJECTIVE: We describe the case of a diabetic patient who developed vertebral osteomyelitis and bilateral psoas abscess with gas formation due to klebsiella pneumoniae. METHODS: A 64-year-old woman with a 4-year history of type-2 diabetes mellitus was admitted to the Emergency Department. The subject had a 2-day history of high-grade fever associated with chills and a 5-hour history of consciousness. She received empirical treatment with febrifuge, after which her fever decreased. RESULTS: Her fever recurred after an interval of three hours. A computed tomography scan of the abdomen revealed vertebral osteomyelitis and bilateral psoas muscle abscess with gas formation. Blood culture and purulent fluid described the growth of the Klebsiella pneumoniae. The patient received antibiotic therapy and bilateral drainage therapy after the drainage catheter was placed into the abscess cavity by CT-guidance. Due to the serious damage to the vertebral column and permanent pain, the patient underwent minimally invasive internal spinal fixation and recovered successfully. CONCLUSION: A case of vertebral osteomyelitis and bilateral psoas abscess with gas formation caused by Klebsiella pneumoniae in a diabetic patient. Antibiotic therapy, drainage, and minimally invasive internal spinal fixation were performed, which enabled a good outcome.

RESUMO OBJETIVO: Descrever o caso de uma paciente diabética que desenvolveu osteomielite vertebral e abcesso bilateral do psoas com formação de gás causada por klebsiella pneumoniae. MÉTODOS: Uma mulher de 64 anos de idade, com 4 anos de histórico de diabetes mellitus tipo 2, foi admitida no Serviço de Emergência. A paciente apresentava um quadro de dias de febre alta acompanhada de calafrios e um histórico de 5 horas de consciência. Ela recebeu tratamento empírico com antitérmico, após o qual a febre diminuiu. RESULTADOS: A febre retornou após um intervalo de três horas. Uma tomografia computadorizada do abdome revelou osteomielite vertebral e abcesso bilateral do músculo psoas com formação de gás. A cultura do sangue e o fluido purulento revelaram o crescimento de Klebsiella pneumoniae. A paciente recebeu antibióticos e terapia de drenagem bilateral após o cateter de drenagem ser posicionado na cavidade do abscesso com auxílio de TC. Devido a sérios danos à coluna vertebral e a dor permanente, a paciente foi submetida à fixação vertebral interna minimamente invasiva e recuperou-se com sucesso. CONCLUSÃO: Um caso de osteomielite vertebral e abscesso do psoas bilateral com a formação de gás causada por Klebsiella pneumoniae em uma paciente diabética. Antibioticoterapia, drenagem e fixação vertebral interna minimamente invasiva foram realizadas, o que permitiu um bom resultado.

Macrophage migration inhibitory factor (MIF) inhibitor 4-IPP suppresses osteoclast formation and promotes osteoblast differentiation through the inhibition of the NF-κB signaling pathway.

Current pharmacological intervention for the treatment of osteolytic bone diseases such as osteoporosis focuses on the prevention of excessive osteoclastic bone resorption but does not enhance osteoblast-mediated bone formation. In our study, we have shown that 4-iodo-6-phenylpyrimidine (4-IPP), an irreversible inhibitor of macrophage migration inhibitory factor (MIF), can inhibit receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis and potentiate osteoblast-mediated mineralization and bone nodule formation in vitro. Mechanistically, 4-IPP inhibited RANKL-induced p65 phosphorylation and nuclear translocation by preventing the interaction of MIF with thioredoxin-interacting protein-p65 complexes. This led to the suppression of late osteoclast marker genes such as nuclear factor of activated T cells cytoplasmic 1, resulting in impaired osteoclast formation. In contrast, 4-IPP potentiated osteoblast differentiation and mineralization also through the inhibition of the p65/NF-κB signaling cascade. In the murine model of pathologic osteolysis induced by titanium particles, 4-IPP protected against calvarial bone destruction. Similarly, in the murine model of ovariectomy-induced osteoporosis, 4-IPP treatment ameliorated the bone loss associated with estrogen deficiency by reducing osteoclastic activities and enhancing osteoblastic bone formation. Collectively, these findings provide evidence for the pharmacological targeting of MIF for the treatment of osteolytic bone disorders.-Zheng, L., Gao, J., Jin, K., Chen, Z., Yu, W., Zhu, K., Huang, W., Liu, F., Mei, L., Lou, C., He, D. Macrophage migration inhibitory factor (MIF) inhibitor 4-IPP suppresses osteoclast formation and promotes osteoblast differentiation through the inhibition of the NF-κB signaling pathway.

Cement Distribution Patterns Are Associated with Recompression in Cemented Vertebrae After Percutaneous Vertebroplasty: A Retrospective Study.

OBJECTIVE: To reevaluate the cement distribution patterns and further investigate associations between cement distribution patterns and the occurrence rates of recompression in cemented vertebrae after percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures. METHODS: Two hundred twenty-four patients with a mean age of 71.9 years were enrolled and treated with single-level PVP between June 2012 and July 2015. The mean follow-up time was 16.5 months. Data from medical records and radiographs were collected and analyzed. Cement distribution patterns were divided into 4 cement distribution patterns extending from the traditional 2 patterns: interlocked solid pattern (LS) and uninterlocked solid pattern (ULS); contiguous trabecular pattern (CT) and discontiguous trabecular pattern (DCT). Differences in treatment efficacy and the occurrence rates of recompression in cemented vertebrae were compared for both groups using the Wilcoxon rank sum test and chi-squared test. RESULTS: Thirty-seven patients who underwent PVP developed recompression in cemented vertebrae. Recompression in cemented vertebrae was significantly more frequent in the ULS and DCT groups than in the LS and CT groups (P < 0.05 or 0.001), with the Visual Analogue Scale score at the time of final follow-up was also significantly higher in the ULS and DCT groups (P < 0.001). CONCLUSIONS: Significant associations were found between cement distribution patterns and recompression in cemented vertebrae, which affected the clinical outcome in patients after PVP. A higher incidence of recompression in cemented vertebrae was seen in patients with treated vertebrae exhibiting ULS pattern or DCT pattern.

Anterior reconstruction versus posterior osteotomy in treating Kümmell's disease with neurological deficits: A systematic review.

OBJECTIVE: This study aimed to conduct a systematic review of literature comparing the clinical effectiveness and safety between anterior reconstruction (AR) and posterior osteotomy (PO) in the treatment of Kümmell's disease with neurological deficits. METHODS: We systematically reviewed the literature in PubMed, EMBASE, Cochrane Database of Systematic Reviews, and the Web of Science for "spin*," "surg*," "Kümmell's disease," "Kummell's disease," "Kummell disease," "vertebral osteonecrosis," "vertebral pseudarthrosis," "intravertebral vacuum cleft," "delayed vertebral collapse," and "compression fracture nonunion". Quality was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation method. RESULTS: A total of 10 publications involving 268 Kümmell's disease patients with neurological deficits were included in this review, with 7 studies of low- or very low-quality. There were 37.7% and 62.3% of patients receiving AR and PO, respectively. For clinical outcomes, AR group showed no significant differences in pain, neurological dysfunction, and imaging outcome improvements compared with patients who underwent PO. However, the incidence of implant-related complications including loose screw, screw fracture, screw disconnection, and plate dislodgment, was higher in AR group compared with PO group (21.6% vs. 14.3%). As another major complication, AR group more often required a second surgery. CONCLUSION: This systematic review demonstrated that both AR and PO could improve pain, neurological dysfunction and imaging outcomes. However, serious comorbidities, multilevel corpectomies and/or severe osteoporosis highly required PO. Design discrepancies were found in the current studies, further higher-quality studies are warranted. LEVEL OF EVIDENCE: Level III, therapeutic study.

Association between menopause and lumbar disc degeneration: an MRI study of 1,566 women and 1,382 men.

OBJECTIVE: The aim of this study was to revisit and further investigate the association between menopause and disc degeneration in the lumbar spine using a magnetic resonance imaging-based eight-level grading system. METHODS: This study cohort comprised of 1,566 women and 1,382 age-matched men who were admitted for low back pain from June 2013 to October 2016. Data on age, weight, height, body mass index, age at natural menopause, and years since menopause (YSM) were obtained. Lumbar disc degeneration was assessed using a magnetic resonance imaging-based eight-level grading system. RESULTS: After adjustment for the confounding factors of age, height, and weight, young age-matched men were more susceptible to disc degeneration than premenopausal women (P < 0.05). However, after menopause, postmenopausal women had a significant tendency to develop more severe disc degeneration than their age-matched men (P < 0.05), and also compared with premenopausal and perimenopausal women (P < 0.01). Postmenopausal women were divided into nine subgroups by every 5 YSM. When YSM was less than 15 years, a positive trend was observed between YSM and severity of disc degeneration, respectively, at L1/L2 (r = 0.241), L2/L3 (r = 0.193), L3/L4 (r = 0.191), L4/L5 (r = 0.165), L5/S1 (r = 0.153), and all lumbar discs (r = 0.237) (P < 0.05 or 0.01). The analysis of covariance indicated a significant difference in each disc level (P < 0.05 or 0.01) between every two groups. When YSM was more than 15 years, the significant difference, however, disappeared in each disc level (P > 0.05). CONCLUSIONS: Menopause is associated with lumbar disc degeneration. The association occurred in the first 15 YSM, suggesting estrogen deficiency might be a risk factor of disc degeneration of the lumbar spine. Further studies need to be carried out for deciding whether age or menopause plays a more important role in the progression of disc degeneration in the lumbar spine.

Cleavage of fusion proteins on the affinity resins using the TEV protease variant.

It is documented that the tobacco etch virus protease (TEVp) variant TEVp3M is less efficient in cleaving the fusion protein bound to Ni-NTA resin at relatively low temperature. Here, we determined that, using the GFP fusion substrate bound to Ni-NTA or Strep-tactin agarose, activity of the TEVp5M variant was higher than that of the other TEVp construct, and about 15% higher than that of the TEVp3M. The GST fusion proteins immobilized on Strep-tactin agarose or Glutathione Sepharose were efficiently cleaved by purified TEVp5M at specified conditions using GFP reporter for visual track and detection. After on-column cleavage of three fusion constructs using the cognate TEVp5M constructs, two target proteins with relatively high purity were separated from Ni-NTA or Amylose agarose. With elution of the buffer containing 1 M NaCl, maize sulfiredoxin was released from Ni-NTA resin via on-column cleavage. Our results confirmed that TEVp5M efficiently cleaved the fusion proteins bound to the four affinity matrices. By combination with appropriate affinity handles, the cognate TEVp5M mediating tag removal enabled purification and cleavage of the fusion proteins, removal of the protease, and separation of the target proteins from the affinity resin to be accomplished in one step.

Pathogenesis of the intravertebral vacuum of Kümmell's disease.

In this review, we explored the progress of the pathogenesis of Kümmell's disease intravertebral vacuum. Using different expressions of the same disease including 'Kümmell's disease', 'avascular necrosis after vertebral compression fracture (VCF)', 'post-traumatic vertebral osteonecrosis', 'vertebral pseudarthrosis', 'intravertebral vacuum (cleft or gas)', 'delayed vertebral collapse', 'VCF nonunion', and by conducting a search of the PubMed database, we analyzed the results to examine the pathogenesis of the intravertebral vacuum of Kümmell's disease after referring to pertinent literature on intravertebral vacuum of ischemic necrosis after VCF, and exploring the progress of pathogenesis of this disease. A number of discrepancies were identified within the pathogenesis of the intravertebral vacuum after VCF. There were statements such as avascular necrosis of the vertebral body, bone biomechanics, gas forming and other types of claims, all of which obtained clinical and biomechanical supporting evidence. Collectively, most of the researchers believe that Kümmell vertebral fracture syndrome was the comprehensive effect of multiple factors including osteoporosis, avascular necrosis of the vertebral body, and biomechanical changes following fracture. However, there are a number of discrepancies to be resolved and future studies are therefore needed.

Plumbagin exerts protective effects in nucleus pulposus cells by attenuating hydrogen peroxide-induced oxidative stress, inflammation and apoptosis through NF-κB and Nrf-2.

Plumbagin, one of the constituents responsible for the various biological activities of Plumbago zeylanica has been demonstrated to possess antioxidant activity, which may inhibit lipid peroxidation in a dose- and time-dependent manner. In the present study, we aimed to examine the protective effects of plumbagin as well as the underlying mechansim through which plumbagin attenuates hydrogen peroxide (H2O2)-induced oxidative stress in nucleus pulposus cells (NPCs). For this purpose, the NPCs were incubated with fresh medium containing H2O2 (200 µM) at 37˚C in a humidified 5% CO2 atmosphere for 6 h, and cultured with various concentrations of plumbagin (0, 0.5, 1, 2, 5, 10 and 20 µM). Treatment with plumbagin significantly increased the viability of the H2O2-exposed NPCs in a dose­dependent manner. Moreover, plumbagin significantly reduced the generation of reactive oxygen species, lipid peroxidation, as well as the levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß and IL-6 in the H2O2­exposed NPCs. Glutathione (GSH) content, as well as the activity of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxdiase (GSH-Px) were increased. We found that the administration of plumbagin significantly inhibited the activity of caspase-9 and -3, and downregulated NF-κB expression and upregulated Nrf-2 expression in the H2O2-exposed NPCs. Taken together, these findings suggest that plumbagin exerts neuroprotective effects in NPCs by attenuating H2O2­induced oxidative stress, inflammation and apoptosis through mediating the expression of NF-κB and Nrf-2.

Intradural extramedullary capillary hemangioma: A case report and review of the literature.

Capillary hemangiomas are benign tumors frequently located in the skin and other soft tissues during childhood. However, intradural extramedullary capillary hemangioma is extremely rare. The current study reports a rare case of intradural extramedullary capillary in a 59-year-old woman who presented with backache and right lower limb numbness that had progressed over 20 days. Magnetic resonance imaging of the thoracic spine showed an ill-defined mass at the T8 level. All other examinations were normal. The patient underwent surgery and recovered successfully. Histopathological examinations showed that the tumor exhibited the typical histological findings of capillary hemangioma, as it was comprised of a proliferation of capillary-sized vessels. The patient remains alive with no evidence of tumor metastasis and recurrence at 24 months post-surgery.

Genome-wide analysis of the IQD gene family in maize.

IQD gene family plays important roles in plant developmental processes and stress responses. To date, no systematic characterization of this gene family has been carried out in maize. In this study, 26 IQD genes, from ZmIQD1 to ZmIQD26, were identified using Blast search tools. The phylogenetic analysis showed these genes were divided into four subfamilies (IQD I-IV) and members within the same subfamily shared conserved exon/intron distribution and motif composition. The 26 ZmIQD genes are distributed unevenly on 8 of the 10 chromosomes, with 9 segmental duplication events, suggesting that the expansion of IQDs in maize was due to the segmental duplication. The analysis of Ka/Ks ratios showed that the duplicated ZmIQDs had primarily undergone strong purifying selection. In addition, the 26 ZmIQDs displayed different expression patterns at different developmental stages of maize based on transcriptome analysis. Further, quantitative real-time PCR analysis showed that all 26 ZmIQD genes were responsive to drought treatment, suggesting their crucial roles in drought stress response. Yeast two-hybrid assay proved that ZmIQD2 and ZmIQD15 can interact with ZmCaM2 and IQ or I in IQ motif is required for ZmIQD15 to combine with CaM2. Our results present a comprehensive overview of the maize IQD gene family and lay an important foundation for further analysis aimed at uncovering the biological functions of ZmIQDs in growth and development.

Alterations in enterocyte mitochondrial respiratory function and enzyme activities in gastrointestinal dysfunction following brain injury.

AIM: To determine the alterations in rat enterocyte mitochondrial respiratory function and enzyme activities following traumatic brain injury (TBI). METHODS: Fifty-six male SD rats were randomly divided into seven groups (8 rats in each group): a control group (rats with sham operation) and traumatic brain injury groups at 6, 12, 24 h, days 2, 3, and 7 after operation. TBI models were induced by Feendy's free-falling method. Mitochondrial respiratory function (respiratory control ratio and ADP/O ratio) was measured with a Clark oxygen electrode. The activities of respiratory chain complex I-IV and related enzymes were determined by spectrophotometry. RESULTS: Compared with the control group, the mitochondrial respiratory control ratio (RCR) declined at 6 h and remained at a low level until day 7 after TBI (control, 5.42 ± 0.46; 6 h, 5.20 ± 0.18; 12 h, 4.55 ± 0.35; 24 h, 3.75 ± 0.22; 2 d, 4.12 ± 0.53; 3 d, 3.45 ± 0.41; 7 d, 5.23 ± 0.24, P < 0.01). The value of phosphate-to-oxygen (P/O) significantly decreased at 12, 24 h, day 2 and day 3, respectively (12 h, 3.30 ± 0.10; 24 h, 2.61 ± 0.21; 2 d, 2.95 ± 0.18; 3 d, 2.76 ± 0.09, P < 0.01) compared with the control group (3.46 ± 0.12). Two troughs of mitochondrial respiratory function were seen at 24 h and day 3 after TBI. The activities of mitochondrial complex I (6 h: 110 ± 10, 12 h: 115 ± 12, 24 h: 85 ± 9, day 2: 80 ± 15, day 3: 65 ± 16, P < 0.01) and complex II (6 h: 105 ± 8, 12 h: 110 ± 92, 24 h: 80 ± 10, day 2: 76 ± 8, day 3: 68 ± 12, P < 0.01) were increased at 6 h and 12 h following TBI, and then significantly decreased at 24 h, day 2 and day 3, respectively. However, there were no differences in complex I and II activities between the control and TBI groups. Furthermore, pyruvate dehydrogenase (PDH) activity was significantly decreased at 6 h and continued up to 7 d after TBI compared with the control group (6 h: 90 ± 8, 12 h: 85 ± 10, 24 h: 65 ± 12, day 2: 60 ± 9, day 3: 55 ± 6, day 7: 88 ± 11, P < 0.01). The changes in α-ketoglutaric dehydrogenase (KGDH) activity were similar to PDH, except that the decrease in KGDH activity began at 12 h after TBI (12 h: 90 ± 12, 24 h: 80 ± 9, day 2: 76 ± 15, day 3: 68 ± 7, day 7: 90 ± 13, P < 0.01). No significant change in malate dehydrogenase (MDH) activity was observed. CONCLUSION: Rat enterocyte mitochondrial respiratory function and enzyme activities are inhibited following TBI. Mitochondrial dysfunction may play an important role in TBI-induced gastrointestinal dysfunction.

Anti-allodynia effect of safranal on neuropathic pain induced by spinal nerve transection in rat.

In this study, we investigated the anti-allodynia effect of safranal, the main volatile constitute of saffron, in spinal nerve transection model of rats. Meanwhile, to elucidate the mechanism, we determined the dynamic expression changes of glial activation markers (GFAP and OX-42) and inflammatory cytokines (TNF-α and IL-1ß) in ipsilateral dorsal horn of lumbar enlargement post surgery. Results showed significant increase of these markers along with development of mechanical allodynia. Safranal (0.1 mg/kg, i.p.) attenuated the pain sensitivity and inhibited the expression of these markers. The results demonstrate that the antiallodynia effect of safranal after nerve injury might be attributed to its inhibiting effect on glial activation and inflammatory cytokine production in central nervous system.

Internal fixation with percutaneous kyphoplasty compared with simple percutaneous kyphoplasty for thoracolumbar burst fractures in elderly patients: a prospective randomized controlled trial.

PURPOSE: The impact of percutaneous internal fixation as a supplement to percutaneous kyphoplasty (PKP) for the management of thoracolumbar burst fractures in elderly patients is unclear. We conducted a clinical controlled trial to investigate the effect and outcomes of this technique in such patients. METHODS: Forty-three patients over 65 years old with thoracolumbar burst fractures without nerve injuries were enrolled. They were randomly assigned to treatment with simple PKP (control group, n = 22) or percutaneous short-segment pedicle screw internal fixation with PKP (treatment group, n = 21). The patients were followed for at least 2 years postoperatively and were assessed with regard to clinical and radiological outcomes. Clinical outcomes were evaluated mainly with use of visual analog scale (VAS) for pain and the Oswestry Disability Index (ODI) questionnaire. Radiological outcomes were assessed mainly on the basis of Cobb kyphosis angle and loss of kyphosis correction. RESULTS: There were no significant differences between the two groups with regard to preoperative indices. The treatment group had better VAS scores and greater postoperative improvement on the ODI compared with the control group (P < 0.05). Postoperative kyphosis angle correction in the treatment group was superior to that in the control group, and loss of correction postoperatively was significantly less (P < 0.05). In the control group, two patients suffered refractures of the injured vertebra postoperatively and one had a fracture in the adjacent vertebra. No postoperative complications needing management were noted in either group. CONCLUSIONS: Compared with simple PKP, percutaneous internal fixation with PKP is a valuable surgical option for the treatment of selected elderly patients with thoracolumbar burst fractures.

[Centerpiece plating in the cervical single open-door laminoplasty].

OBJECTIVE: To evaluate the value of the Centerpiece plate in the cervical single open-door laminoplasty and compared its advantages with conventional suture fixation methods. METHODS: From December 2009 to August 2011,32 patients with cervical spondylotic myelopathy were treated with operation. Of them, 15 cases underwent cervical single open-door laminoplasty and Centerpiece plate fixation (group A),there were 8 males and 7 females,aged from 51 to 65 years old with an average of 60.5 years and ranged in course of disease from 2 to 15 months; 17 cases underwent cervical single open-door laminoplasty and silk suture fixation (group B), there were 9 males and 8 females, aged from 49 to 66 years old with an average of 61.5 years and ranged in course of disease from 1 to 14 months. All the patients with unsteady gait symptom before operation and cervical MR imaging showed spinal cord compression and denaturation. According to standard of Japanese Orthopaedics Association (JOA) to evaluate the spinal nervers function before operation and at 6 months after operation;according to CT scan to determine the sagittal diameter (AP) of upper vertebral canal and cervical activity (ROM). RESULTS: All the patients were followed up from 8 to 20 months with an average of 13 months. All the incisions healed well and no complications such as internal fixation loosening and breakage,spinal cord injury, reclose-door were found. Postoperative symptoms relieved obviously and MRI and CT showed vertebral canal volume expanded significantly. Operative time and blood loss in group A were respectively (155.0+/-12.3) min, (407.0+/-11.8) ml and in group B were respectively (148.0+/-14.4) min, (398.0+/-15.4) ml. There was no significantly differenc, between two groups (P>0.05). JOA score in group A improved from preoperative 9.1+/-2.6 to postoperative 15.5+/-1.8 and in group B improved from preoperative 9.3 +/- 2.1 to postoperative 13.1 +/- 2.5 (P<0.05). CT sagittal diameter (AP) in group A increased from preoperative (10.7+/-2.4) mm to postoperative (17.6+/-3.2) mm and in group B increased from preoperative (11.6+/-1.7) mm to postoperative (15.9+/-2.0) mm (P<0.05). Cervical activity (ROM) in group A be- fore and after operation were respectively (51.0+/-2.6) degrees, (45.0+/-3.5) degrees and in group B were respectively (52.0+/-1.8) and (42.0+/-2.4). There was no significantly difference before operation between two groups (P>0.05) and there was significantly difference after operation between two groups (P<0.05). CONCLUSION: Treatment of cervical spondylotic myelopathy with posterior single open-door laminoplasty and Centerpiece plate fixation can enlarge spinal canal volume,keep original cervical activity, improve postoperative JOA score. The method has obviously advantages compared with traditional suture fixation methods.

A Unified Approach of Meta-Analysis: Application to an Antecedent Biomarker Study in Alzheimer's Disease.

This article provides a unified methodology of meta-analysis that synthesizes medical evidence by using both available individual patient data (IPD) and published summary statistics within the framework of likelihood principle. Most up-to-date scientific evidence on medicine is crucial information not only to consumers but also to decision makers, and can only be obtained when existing evidence from the literature and the most recent individual patient data are optimally synthesized. We propose a general linear mixed effects model to conduct meta-analyses when individual patient data are only available for some of the studies and summary statistics have to be used for the rest of the studies. Our approach includes both the traditional meta-analyses in which only summary statistics are available for all studies and the other extreme case in which individual patient data are available for all studies as special examples. We implement the proposed model with statistical procedures from standard computing packages. We provide measures of heterogeneity based on the proposed model. Finally, we demonstrate the proposed methodology through a real life example studying the cerebrospinal fluid biomarkers to identify individuals with high risk of developing Alzheimer's disease when they are still cognitively normal.

[Progress of enzyme in mitochondrial DNA repair system].

Mitochondrial DNA (mtDNA) encodes subunits of the mitochondrial electron transport system and the rRNAs and tRNAs required for constructing the mitochondrial translational machinery. Each subunit encoded by mtDNA is essential for normal oxidative phosphorylation. Thus, integrity of the mtDNA is crucial for the survival of organisms. It has long been held that there is no DNA repair in mitochondria. But in recent years,a number of repair factors have been found in mitochondrial extracts, suggesting the presence of DNA repair in mitochondria. This review summarized recent progress of enzyme in mitochondrial DNA repair processes.