Enhanced Antibacterial and Osteogenic Properties of Graphene Oxide Loaded with Berberine on Biomedical Titanium.

Internal implants are widely used in most orthopedic surgeries, of which titanium and its alloys are most widely used owing to the excellent corrosiveness resistance, low elastic modulus and good biocompatibility. However, implant failure still occurs for that titanium and its alloys themselves do not own antibacterial and osteogenic properties. In this work, we successfully fabricated berberine-loaded graphene oxide (GO) on the surface of biomedical titanium and systematically investigated its capabilities of antibacteria and osteogenesis. In vitro results showed that berberine had low antibacterial activity, but GO loaded with berberine on titanium (Ber&GO@Ti) exhibited superior antibacterial activity against Staphylococcus aureus (S. aureus) with the synergistic effect of GO and berberine. Meanwhile, Ber&GO@Ti performed satisfactory cytocompatibility and was capable of promoting osteogenic differentiation of MC3T3-E1 cells. In the vivo experiment, Ber&GO@Ti showed excellent antibacterial properties and inflammatory cells e.g., neutrophils had seldom been found. No visceral toxicity had been found. This multifunctional coating showed great potential in orthopedic implants.

How much space of the spinal canal should be restored by hoisting the vertebrae-OPLL complex for sufficient decompression in anterior controllable antedisplacement and fusion? A multicenter clinical radiological study.

BACKGROUND CONTEXT: Anterior controllable antedisplacement and fusion (ACAF) is a novel surgical technique for the treatment of ossification of the posterior longitudinal ligament (OPLL). Its prognostic factors for decompression have not been well studied. Additionally, no detailed radiological standard has been set for hoisting the vertebrae-OPLL complex (VOC) in ACAF. PURPOSE: To identify the possible prognostic factors for decompression outcomes after ACAF for cervical OPLL, to determine the critical value of radiological parameters for predicting good outcomes, and to establish a radiological standard for hoisting the VOC in ACAF. STUDY DESIGN: This was a retrospective multicenter study. PATIENT SAMPLE: A total of 121 consecutive patients with OPLL who underwent ACAF at a point between January 2017 and June 2018 at any one of seven facilities and were monitored for at least 1 year afterward were enrolled in a multicenter study. OUTCOME MEASURES: Japanese Orthopedic Association (JOA) scores, recovery rate (RR) of neurologic function, and surgical complications were used to determine the effectiveness of ACAF. METHODS: Patients were divided into two groups according to their RR for neurologic function. Patients with an RR of ≥50% and an RR of <50% were designated as having good and poor decompression outcomes, respectively. The relationship between various possible prognostic factors and decompression outcomes was assessed by univariate and multivariate analysis. The receiver operating characteristic curve was used to determine the optimal cutoff value of the radiological parameters for prediction of good decompression outcomes. Next, the patients were redivided into three groups according to the cutoff value of the selected radiological parameter (postoperative anteroposterior canal diameter [APD] ratio). Patients with postoperative APD ratios of ≤80.7%, 80.7%-100%, and ≥100% were defined as members of the incomplete, optimal, and excessive antedisplacement groups, respectively. Differences in decompression outcomes among the three groups were compared to verify the reliability of the postoperative APD ratio and assess the necessity of excessive antedisplacement. RESULTS: Multivariate logistic regression analysis showed that patients' age at surgery (odds ratio [OR]=1.18; 95% confidence interval [CI]=1.08-1.29; p<.01) and postoperative APD ratio (OR=0.83; 95% CI=0.77-0.90; p<.01) were independently associated with decompression outcomes. The optimal cutoff point of the postoperative APD ratio was calculated at 80.7%, with 86.2% sensitivity and 73.5% specificity. There were no significant differences in the postoperative JOA scores and RRs between the excessive antedisplacement group and optimal antedisplacement group (p>.05). However, a lower incidence of cerebrospinal fluid leakage and screw slippage was observed in the optimal antedisplacement group (p<.05). CONCLUSIONS: Patients' age at surgery and their postoperative APD ratio are the two prognostic factors of decompression outcomes after ACAF. The postoperative APD ratio is also the most accurate radiological parameter for predicting good outcomes. Our findings suggest that it is essential for neurologic recovery to restore the spinal canal to more than 80.7% of its original size (postoperative APD ratio >80.7%), and restoration to less than its original size (postoperative APD ratio <100%) will help reduce the incidence of surgical complications. This may serve as a valuable reference for establishment of a radiological standard for hoisting the VOC in ACAF.

HIF1/2α mediates hypoxia-induced LDHA expression in human pancreatic cancer cells.

Glycolysis is a typical conduit for energy metabolism in pancreatic cancer (PC) due to the hypoxic microenviroment. Lactate dehydrogenase A (LDHA) catalyzes the conversion of pyruvate to lactate and is considered to be a key checkpoint of anaerobic glycolysis. The aim of the present study was to explore the mechanism of interactions between hypoxia, HIF-1/2α and LDHA, and the function of LDHA on PC cells by analyzing 244 PC and paratumor specimens. It was found that LDHA was over-expressed and related to tumor stages. The result of in vitro study demonstrated that hypoxia induced LDHA expression. To explore the relationship between HIF and LDHA, chromatin immunoprecipitation assay and luciferase assay were performed. The result showed that HIF-1/2α bound to LDHA at 89bp under the hypoxic condition. Furthermore, knockdown of endogenous HIF-1α and HIF-2α decreased the LDHA expression even in the hypoxic condition, which was accompanied with a significant decrease in lactate production and glucose utilization (p < 0.01). Immunofluorescence in the 244 specimens showed that HIF-1/2α was over-expressed and associated with LDHA over-expression (p < 0.0001). Forced expression of LDHA promoted the growth and migration of PC cells, while knocking down the expression of LDHA inhibited the cell growth and migration markedly. In summary, the present study proved that HIF1/2α could activate LDHA expression in human PC cells, and high expression of LDHA promoted the growth and migration of PC cells.

HIF-1α activates hypoxia-induced BCL-9 expression in human colorectal cancer cells.

B-cell CLL/lymphoma 9 protein (BCL-9), a multi-functional co-factor in Wnt signaling, induced carcinogenesis as well as promoting tumor progression, metastasis and chemo-resistance in colorectal cancer (CRC). However, the mechanisms for increased BCL-9 expression in CRC were not well understood. Here, we report that hypoxia, a hallmark of solid tumors, induced BCL-9 mRNA expression in human CRC cells. Analysis of BCL-9 promoter revealed two functional hypoxia-responsive elements (HRE-B and HRE-C) that can be specifically bound with and be transactivated by hypoxia inducible factors (HIF) -1α but not HIF-2α. Consistently, ectopic expression of HIF-1α but not HIF-2α transcriptionally induced BCL-9 expression levels in cells. Knockdown of endogenous HIF-1α but not HIF-2α by siRNA largely abolished the induction of HIF by hypoxia. Furthermore, there was a strong association of HIF-1α expression with BCL-9 expression in human CRC specimens. In summary, results from this study demonstrated that hypoxia induced BCL-9 expression in human CRC cells mainly through HIF-1α, which could be an important underlying mechanism for increased BCL-9 expression in CRC.

En Bloc Resection of Primary Malignant Bone Tumor in the Cervical Spine Based on 3-Dimensional Printing Technology.

OBJECTIVE: To investigate the feasibility and safety of en bloc resection of cervical primary malignant bone tumors by a combined anterior and posterior approach based on a three-dimensional (3-D) printing model. METHODS: Five patients with primary malignant bone tumors of the cervical spine underwent en bloc resection via a one-stage combined anteroposterior approach in our hospital from March 2013 to June 2014. They comprised three men and two women of mean age 47.2 years (range, 26-67 years). Three of the tumors were chondrosarcomas and two chordomas. Preoperative 3-D printing models were created by 3-D printing technology. Sagittal en bloc resections were planned based on these models and successfully performed. A 360° reconstruction was performed by spinal instrumentation in all cases. Surgical margins, perioperative complications, local control rate and survival rate were assessed. RESULTS: All patients underwent en bloc excision via a combined posterior and anterior approach in one stage. Mean operative time and estimated blood loss were 465 minutes and 1290 mL, respectively. Mean follow-up was 21 months. Wide surgical margins were achieved in two patients and marginal resection in three; these three patients underwent postoperative adjuvant radiation therapy. One vertebral artery was ligated and sacrificed in each of three patients. Nerve root involved by tumor was sacrificed in three patients with preoperative upper extremity weakness. One patient (Case 3) had significant transient radiculopathy with paresis postoperatively. Another (Case 4) with C 4 and C 5 chordoma had respiratory difficulties and pneumonia after surgery postoperatively. He recovered completely after 2 weeks' management with a tracheotomy tube and antibiotics in the intensive care unit. No cerebrovascular complications and wound infection were observed. No local recurrence or instrumentation failure were detected during follow-up. CONCLUSION: Though technically challenging, it is feasible and safe to perform en bloc resection of cervical primary bone tumors. This is the most effective means of managing cervical spine tumors. Preoperative 3-D printing modelling enables better anatomical understanding of the relationship between the tumor and cervical spine and can assist in planning the surgical procedure.

The valuation of using FDG PET-CT in detecting osteoid osteoma of the cervical spine.

STUDY DESIGN: Osteoid osteomas (OOs) are bone tumors that rarely occur in the cervical spine. The current study is a retrospective analysis on 10 patients who were diagnosed with this rare spinal bone tumor. We have excised OOs of the cervical spine with the use of FDG Positron emission tomography-computed tomography (PET-CT) for preoperative diagnosis. OBJECTIVE: With the help of the FDG PET-CT, we can confidently remove the nidus of the OOs, while minimize iatrogenic injury of the surrounding normal bone elements, and preserve the stability of the cervical spine. SUMMARY OF BACKGROUND DATA: OO of the cervical spine is frequently located at the nerve root adjacent to the vertebral artery, spinal cord. PET-CT is a sensitive tool with applications in the detection of bone lesions, especially in patients with difficult diagnosis or continuing misdiagnosis of tumors. MATERIALS AND METHODS: Ten patients (8 male and 2 female patients) underwent surgery for tumor removal using PET-CT in our department. Various diagnostic imaging modalities including x-ray, magnetic resonance imaging, CT, bone scintigraphy, and PET-CT were used. PET-CT scan results were measured using standard uptake value. (The size of the cases series was from 4×5 mm to 12×15 mm.) Pain was evaluated using the visual analogue score. Clinical outcome was evaluated immediately postoperatively and at a mean follow-up of 49.8±0.2 months (range, 7-92 mo). RESULTS: All tumors were successfully diagnosed with the use of PET-CT. The average standard uptake value was 2.7±0.1 (range, 2.0-3.4). The nidus of the OO was detected and removed, and the peripheral elements were preserved. The visual analogue score was 8.1±0.1 preoperation, and it significantly decreased to 2.5±0.3 (P<0.01) postoperation and 0.2±0.1 (P<0.01) at the final visit. Immediately after surgery, the patients were relieved of their pain symptoms. There was no injury of the vertebral artery, leakage of cerebrospinal fluid, infectious complications, and neurological injury during the procedure. CONCLUSIONS: It is valuable of using of PET-CT to diagnose OOs of the cervical vertebra. Subsequently, it is a good way that helps us in efficient removal of the OOs completely.

Transient early neurotrophin release and delayed inflammatory cytokine release by microglia in response to PAR-2 stimulation.

Activated microglia exerts both beneficial and deleterious effects on neurons, but the signaling mechanism controlling these distinct responses remain unclear. We demonstrated that treatment of microglial cultures with the PAR-2 agonist, 2-Furoyl-LIGRLO-NH2, evoked early transient release of BDNF, while sustained PAR-2 stimulation evoked the delayed release of inflammatory cytokines (IL-1 ß and TNF-α) and nitric oxide. Culture medium harvested during the early phase (at 1 h) of microglial activation induced by 2-Furoyl-LIGRLO-NH2 (microglial conditioned medium, MCM) had no deleterious effects on cultured neurons, while MCM harvested during the late phase (at 72 h) promoted DNA fragmentation and apoptosis as indicated by TUNEL and annexin/PI staining. Blockade of PAR-1 during the early phase of PAR-2 stimulation enhanced BDNF release (by 11%, small but significant) while a PAR-1 agonist added during the late phase (24 h after 2-Furoyl-LIGRLO-NH2 addition) suppressed the release of cytokines and NO. The neuroprotective and neurotoxic effects of activated microglial exhibit distinct temporal profiles that are regulated by PAR-1 and PAR-2 stimulation. It may be possible to facilitate neuronal recovery and repair by appropriately timed stimulation and inhibition of microglial PAR-1 and PAR-2 receptors.

[Anterior multilevel corpectomy for the treatment of severe ossification of posterior longitudinal ligament in the cervical spine].

OBJECTIVE: To discuss the surgical indications, outcomes and complications of anterior multilevel corpectomy for the treatment of severe ossification of posterior longitudinal ligament (OPLL) in the cervical spine. METHODS: Between April 2006 and March 2008, a total of 25 patients (20 males and 5 females, age range: 42 - 75 yr, mean: 53. 2 yr) underwent anterior multilevel corpectomy for severe ossification of posterior longitudinal ligament in the cervical spine. Radiological studies showed that the type of OPLL was distributed as follows: 7 local, 5 segmental, 8 continuous and 5 mixed. The OPLL extended an average of 2. 8 vertebrae (2 - 4) and the stenotic rate of spinal canal was 68.4% (50% - 97%). After corpectomy and removal of OPLL, titanium mesh cage and anterior plate were employed to restore cervical stability in all patients. RESULTS: Among these patients, 16 underwent two-level corpectomy and 9 three-level corpectomy. After a follow-up of 2 - 18 months, the mean JOA score increased from 9. 3 (5 - 12) points pre-operation to 14.2 (11 - 16) points post-operation. The mean improvement rate of neurological status was 63.2% (22.2% - 87.5%). The complications included CSF leakage in 6 cases (intermittent CSF pseudocyst in 4), nerve root palsy in 2, hematoma in 1 and transient neurological deterioration in 1. CONCLUSION: Anterior multilevel corpextomy can achieve a better clinical outcome in the treatment of severe cervical ossification of posterior longitudinal ligament. But it is technically demanding and carries a higher risk.

The clinical features and surgical treatment of degenerative lumbar scoliosis: a review of 112 patients.

OBJECTIVE: To investigate the clinical features, radiological characteristics and surgical results of degenerative lumbar scoliosis (DLS). METHODS: One hundred and twelve cases of DLS treated surgically from June 2001 to February 2006 were retrospectively reviewed for clinical features, characteristics of nerve root compression and imaging presentations. According to the preoperative clinical manifestations and imaging findings, different surgical modalities were performed, including simple nerve decompression and decompression with short or long posterior fusion (less or more than three segments, respectively). RESULTS: The mean age of 47 male and 65 female patients was 54.7 years. Clinical manifestations included lower back pain (76.8%), radiculopathy (79.5%) and claudication (48.2%). Plain lumbar radiograph showed right scoliosis in 87 and left scoliosis in the other 25 cases; the Cobb angle was 10°-46°; the apex of scoliosis mostly located at L3 (48.2%); L3 and L4 nerve roots were usually compressed on the concave side and L5 and S1 nerve roots on the convex side. The Cobb angle and physiologic lordosis angle of patients who underwent multi-segment (>3 segments) fusion improved to a greater extent than did that of patients who had simple decompression without fusion. A mean 5.7-year follow-up showed that the average improvement in Oswestry disability index (ODI) scores was 32.6, 26.3 and 13.5 for long segment fusion, short segment fusion and simple decompression without fusion, respectively. CONCLUSION: Decompression surgery with or without fusion, the main purpose of which is to relieve nerve root compression and stabilize the spinal column, is an effective treatment for chronic DLS. The treatment should be individualized according to the patient's age, general and economic factors, severity of deformity and other coexisting lumbar degenerative disorders.

[Concentration of endogenous agmatine in normal and injured spinal cord: experiment with rats].

OBJECTIVE: To detect the concentration of endogenous agmatine in normal and injured rats' spinal cord. METHODS: Forty-two SD rats were randomized to sham-operation group and 1 hour, 4 hours, 8 hours, 24 hours, 48 hours, 72 hours after operation groups. The modified Allen's model of spinal cord injury was established. The endogenous agmatine was detected both in normal and injured rats' spinal cord by high-performance liquid chromatography (HPLC) with fluorescence detection and OPA derivatization. RESULTS: The endogenous agmatine level in naive rats' spinal cord were (0.643 +/- 0.111) microg/g wet weight. After spinal cord injury, the concentration had a transient drop followed by significantly increase, and then decreased by degrees. CONCLUSION: Up to now, little has been known about the endogenous agmatine levels in mammalian tissues. The results reported by different authors varied up to hundred times. According to our results and other articles, the endogenous agmatine levels in mammals' central nervous system arranged from 0.2 microg/g to 1.1 microg/g wet weight. Although there was a significant increase after spinal cord injury, the peak concentration was extremely lower than what it needed to take its neuroprotective effect in vitro.

[Diagnosis and treatment for the injury of cervical disc and longitudinal ligament].

OBJECTIVES: To study the diagnosis and treatment for the injury of cervical disc and longitudinal ligament. METHODS: From 2001 to 2005, the clinical data of sixty-three patients with cervical disc and longitudinal ligament injury were studied. Early treatment was done based on spinal cord injuries and spinal stabilities by X rays and MRI. Early operation was done in fifty-four cases and early non-operation in nine cases. RESULTS: The follow-up time was six to forty-one months in all patients. The neurological recovery was found in two of eight complete SCI post-operation, thirty-one in thirty-nine incomplete SCI. Cervical collar or plaster orthotic were used in nine cases with four to six weeks. Evidence of instability was noted in four patients, who were operated with anterior decompression fusion. Neck chronic pain was found in two patients, anterior decompression and fusion was done in one with cervical spinal cord compression. CONCLUSIONS: MRI examination is the most value measure for the diagnosis of cervical disc and longitudinal ligament injury. Early anterior decompression and fusion was an important approach for cervical disc and longitudinal ligament injury.

[Key points about atlanto-axial internal-fixation and fusion using Gallie's technique].

OBJECTIVE: To study the clinical problems about posterior atlanto-axial internal-fixation and fusion for atlanto-axial instability or dislocation. METHODS: Surgical treatments of 138 cases with atlanto-axial instability or dislocation were reviewed. There were 62 cases of odentoid malformation, 54 cases of odentoid fracture or rupture of transverse ligament, 22 cases of subluxation and rotation. All cases were treated using Gallie's technique. Six cases were also fixed with transarticular screws, and protected with Philadelphia collar. Other patients were fixed with plaster paris brackets. The followed-up period was 1 to 12 years with an average of 3 year and 5 months. RESULTS: According to Sumi's criteria, excellent 70 cases (50.7%), good 40 cases (29.0%), fair 15 cases (10.9%), poor 13 cases (9.4%). 9 cases with bone graft postponed fusion were cured by enhance external-fixation. 2 cases with nonunion were treated with revision surgery. Complication of cord injury happened in 1 case. CONCLUSION: Gallie's fusion technique is an effective method to manage the atlanto-axial instability or dislocation. Skull distraction before operation and reliable external-fixation post operative are important assistant measures. Key points for successful operation are careful wiring or cable traversing, decortication of posterior arc of C1, and maintaining the physiological height between C1 and C2 posterior arc. Indications and objectives should be conformed before revision surgery for failure cases.