Regional biomechanical characterization of the spinal cord tissue: dynamic mechanical response.

Characterizing the dynamic mechanical properties of spinal cord tissue is deemed important for developing a comprehensive knowledge of the mechanisms underlying spinal cord injury. However, complex viscoelastic properties are vastly underexplored due to the spinal cord shows heterogeneous properties. To investigate regional differences in the biomechanical properties of spinal cord, we provide a mechanical characterization method (i.e., dynamic mechanical analysis) that facilitates robust measurement of spinal cord ex vivo, at small deformations, in the dynamic regimes. Load-unload cycles were applied to the tissue surface at sinusoidal frequencies of 0.05, 0.10, 0.50 and 1.00 Hz ex vivo within 2 h post mortem. We report the main response features (e.g., nonlinearities, rate dependencies, hysteresis and conditioning) of spinal cord tissue dependent on anatomical origin, and quantify the viscoelastic properties through the measurement of peak force, moduli, and hysteresis and energy loss. For all three anatomical areas (cervical, thoracic, and lumbar spinal cord tissues), the compound, storage, and loss moduli responded similarly to increasing strain rates. Notably, the complex modulus values of ex vivo spinal cord tissue rose nonlinearly with rising test frequency. Additionally, at every strain rate, it was shown that the tissue in the thoracic spinal cord was significantly more rigid than the tissue in the cervical or lumbar spinal cord, with compound modulus values roughly 1.5-times that of the lumbar region. At strain rates between 0.05 and 0.50 Hz, tan δ values for thoracic (that is, 0.26, 0.25, 0.06, respectively) and lumbar (that is, 0.27, 0.25, 0.07, respectively) spinal cord regions were similar, respectively, which were higher than cervical (that is, 0.21, 0.21, 0.04, respectively) region. The conditioning effects tend to be greater at relative higher deformation rates. Interestingly, no marked difference of conditioning ratios is observed among all three anatomical regions, regardless of loading rate. These findings lay a foundation for further comparison between healthy and diseased spinal cord to the future development of spinal cord scaffold and helps to advance our knowledge of neuroscience.

Low TLR and PSMA-TV predict biochemical response to abiraterone acetate in metastatic prostate cancer patients developing castration resistance after chemohormonal therapy at hormone-sensitive stage.

OBJECTIVE: To explore whether 68Ga-PSMA-11 PET/CT-derived parameters could predict biochemical response to abiraterone acetate (AA) treatment and prognosis in metastatic prostate cancer patients developing castration resistance after chemohormonal therapy at hormone-sensitive stage. METHODS: The clinicopathologic data of 106 mCRPC cases receiving AA treatment were retrospectively analyzed. Logistic regression analysis was used to determine the independent predictors of biochemical response to AA treatment. Cox analyses were applied to investigate the independent prognostic factors for time to biochemical progression (TTBP) and radiological progression-free survival (rPFS). Survival analysis and ROC curve were also used. RESULTS: Multivariable Logistic analysis demonstrated that prior ADT duration ≥ 12 months, low prostate specific membrane antigen receptor-expressing tumor volume (PSMA-TV), low tumor to liver ratio (TLR) were independent predictors of biochemical response to AA treatment. Multivariate Cox analysis demonstrated that low PSMA-TV and low TLR were independent prognostic factors of longer TTBP and rPFS. The TTBP and rPFS of patients with higher PSMA-TV or TLR were significantly decreased compared with that of patients with lower PSMA-TV and TLR. The area under ROC curve (AUC) of combining ADT duration, PSMA-TV and TLR was 0.82 for predicting biochemical response to AA, which was significantly increased compared with that of other 68Ga-PSMA-11 PET/CT-derived parameters alone. CONCLUSIONS: Low PSMA-TV, low TLR were vital independent predictors of biochemical response to AA treatment and were associated with preferable prognosis in mCRPC patients. Combining ADT duration, PSMA-TV and TLR performed well in distinguishing AA responders from non-responders in mCRPC patients.

Morphology of Herniated Disc as a Predictor for Outcomes of Posterior Percutaneous Full-endoscopic Cervical Discectomy in Treating Cervical Spondylotic Radiculopathy.

OBJECTIVE: To quantitively characterize the morphology of cervical disc herniation (CDH) causing cervical spondylotic radiculopathy (CSR) and investigate whether the morphological features of CDH are associated with clinical outcomes in CSR patients treated by posterior percutaneous full-endoscopic cervical discectomy (PPECD). METHODS: This is a single-center retrospective study. Eighty-seven PPECD-treated patients meeting the inclusion criteria were included between May 2017 and May 2019. Based on preoperative T2-weighted magnetic resonance imaging (MRI), we designed and measured six morphological parameters of CDH for all patients to reflect its relative position to cervical spinal cord and protruding degree: DC-SC distance from the center of disc (DC) and the center of spinal cord (SC); DC-DP distance from the center of cervical disc (DC) to the peak of herniation (DP); internal diameter of the disc; axial length of CDH; central angle of CDH formed by central axes of CDH and spinal cord; the modified index of CDH. We recorded general information, neck disability index (NDI) scores, visual analog scale (VAS) scores of neck and arm of all patients preoperatively and postoperatively at 1-year follow-up. The association of preoperative general variables and morphological parameters with clinical outcomes were explored by utilizing logistic regression and receiver operating characteristic curve (ROC) analysis. RESULTS: The preoperative neck-VAS, arm-VAS, and NDI were significantly decreased after PPECD and remained at a low value at follow-up. In regards to the morphological parameters of CDH, the mean value of DC-SC distance, DC-DP distance, internal diameter of the disc, axial length of CDH, central angle of CDH, and modified index of CDH were 1.61 ± 0.30 cm, 1.66 ± 0.32cm, 1.04 ± 0.21 cm, 0.63 ± 0.19cm, 39.38° ± 11.94°, and 0.39 ± 0.24, respectively. For patients grouped by difference in the recovery rate of NDI and arm-VAS (excellent improved group, EI; and limited improved group, LI), there were no differences in the age, gender, surgical segments, and morphological parameters, except for the central angle of CDH. According to binary logistic regression analysis, only the preoperative central angle of CDH was significantly associated with postoperative NDI recovery (odds ratio: 0.873; 95% confidence interval: 0.819-0.931, P = 0.002). ROC analysis showed the optimal cut-off value of the central angle of CDH for predicting the postoperative improvement of functional outcomes is 33.788°. CONCLUSION: Preoperative morphology of CDH is related to the outcomes of CSR patients after PPECD. Patients with a large central angle of CDH (>33.788°) have more likelihood of ameliorating neurological symptoms of CSR. There is the potential to select the central angle of CDH as a predictor for outcomes of PPECD in treating CSR.

Sonographic and pathological features of metaplastic squamous cell carcinoma of the breast: a case series.

OBJECTIVE: The aim of this study was to evaluate the sonographic features and to compare the sonographic findings with the pathologic features. METHODS: The sonographic and pathological features of all patients were retrospectively reviewed. RESULTS: All these 9 patients presented with a palpable breast mass first found by the patient before presentation. The median diameters were 3.67 cm. On two-dimensional imaging, 8 masses showed mixed echogenicity with both solid and cystic components, and only 1 mass showed hypoechoic. All the masses had irregular shapes. 1 mass had indistinct margin and 8 masses had microlobulated margins. Calcifications was seen in 1 mass. On color Doppler flow imaging, 8 masses had high vascularity with high resistance index; 5 masses had grade III blood flow signal; 3 masses had grade II blood flow signal. On histopathological examination, 5 masses were adenocarcinoma with squamous metaplasia, and 4 masses were pure SCC. On immunohistochemical staining, estrogen receptors (ER), progesterone receptors (PR) and human epidermal growth factor receptor (HER2) were negative in 5 masses. There were 2 patients with lymph node metastasis. CONCLUSIONS: Most of the sonographic features of MSCC were mixed echogenicity with central cystic components, posterior echo enhancement, abundant vascularity with high resistance.

[High-frequency ultrasonography for evaluation of the urethral stricture model in rats].

OBJECTIVE: To explore the methodology for the establishment of the urethral stricture model in rats, the methods of end-point imaging evaluation of the model establishment and their efficiency. METHODS: Twenty-four adult male rats were randomly divided into a blank control (n = 6) and a model group (n = 18), and the model was established by cutting the penile segment of the urethra to induce incomplete urethral rupture. Then the model rats were treated by injection of transforming growth factor-ß1 (the TGF group, n = 6) or mesenchymal stem cells (the MSC group, n = 12) into the urethral cavernosum. At 4 weeks after modeling, the urethral condition of all the rats was evaluated blindly using high-frequency ultrasound combined with water bath, followed by comparison among different groups. RESULTS: Compared with the blank controls, the model rats showed evident urethral stricture, with more significant urethral fibrous tissue hyperplasia in the TGF than in the MSC group. Ultrasonography revealed significantly narrowed echo strips (P < 0.01), decreased echo intensity and blurred echoes in some strips. The grouping of the model rats according to the assigned values to the ultrasonographic changes was consistent with the actual condition. The area under the ROC curve for distinguishing between the TGF and MSC groups was 0.972, with a sensitivity of 100.0% and a specificity of 83.3% when ultrasound assignment score was 7.5. CONCLUSIONS: High-frequency ultrasonography combined with water bath is effective for evaluating urethral stricture in rats and may give some guidance in the establishment of the urethral stricture model.

Thermosensitive injectable decellularized nucleus pulposus hydrogel as an ideal biomaterial for nucleus pulposus regeneration.

Extracellular matrix loss is one of the early manifestations of intervertebral disc degeneration. Stem cell-based tissue engineering creates an appropriate microenvironment for long term cell survival, promising for NP regeneration. We created a decellularized nucleus pulposus hydrogel (DNPH) from fresh bovine nucleus pulposus. Decellularization removed NP cells effectively, while highly preserving their structures and major biochemical components, such as glycosaminoglycan and collagen II. DNPH could be gelled as a uniform grid structure in situ at 37°C for 30 min. Adding adipose marrow-derived mesenchymal stem cells into the hydrogel for three-dimensional culture resulted in good bioactivity and biocompatibility in vitro. Meanwhile, NP-related gene expression significantly increased without the addition of exogenous biological factors. In summary, the thermosensitive and injectable hydrogel, which has low toxicity and inducible differentiation, could serve as a bio-scaffold, bio-carrier, and three-dimensional culture system. Therefore, DNPH has an outstanding potential for intervertebral disc regeneration.

Dynamic Bioreactor Culture for Infiltration of Bone Mesenchymal Stem Cells within Electrospun Nanofibrous Scaffolds for Annulus Fibrosus Repair.

OBJECTIVE: To compare the ability of three culture strategies of static culture, intermittent centrifugal culture and dynamic bioreactor culture in promoting the infiltration of bone marrow mesenchymal stem cells (BMSCs) throughout electrospun nanoporous aligned nanoyarn scaffold (AYS). METHODS: AYS was constructed by the method of conjugated electrospinning, using the blended solution of poly (L-lactide-co-caprolactone) (P (LLA-CL)) and gelatin. Then the bone marrow mesenchymal stem cells (BMSCs) were transplanted on the scaffolds. Culture the scaffold-cells using three methods of static culture, intermittent centrifugal culture and dynamic bioreactor culture. After 7 and 14 days in culture, the infiltration depth of the cells were observed and measured by hematoxylin and eosin (HE) or 4', 6-diamidino-2-phenylindole (DAPI) staining. RESULT: In the current study, on the 7th day, the BMSCs in the scaffolds of static culture group, intermittent centrifugal culture group, and dynamic bioreactor culture group infiltrated to an average depth of 11.88 ± 1.82 µm, 21.17 ± 13.17 µm, and 26.27 ± 7.42 µm, respectively. There were differences between the bioreactor culture group with the static culture group and the intermittent centrifugal culture group. On the time point of 14 days, the depth of infiltration of BMSCs in dynamic bioreactor culture was the most (115.13 ± 25.44 µm, P < 0.05), and the infiltration of the cells in the intermittent centrifugal culture group was 42.53 ± 13.07 µm, deeper than that of the static culture group (24.53 ± 6.06, P < 0.05). CONCLUSION: Dynamic bioreactor culture may be a preferred method for tissue engineering approaches involving scaffolds with a low porosity, such as those needed for repair of the annulus fibrosus (AF).

Removal of calcified lumbar disc herniation with endoscopic-matched ultrasonic osteotome - Our preliminary experience.

Objective: To evaluate the clinical efficacy, practicability, and safety of an ultrasonic osteotome for percutaneous transforaminal endoscopic discectomy (PTED) in patients with calcified lumbar disc herniation (CLDH).Methods: A total of 25 CLDH patients who underwent PTED at our department between December 2017 and August 2018 were analyzed retrospectively. Post-operative lumbar spine CT was used to evaluate residual calcification. Efficacy was evaluated by pre- and post-operative with the pain visual analog scale (VAS), Oswestry disability index (ODI), and the Modified MacNab Scale; the incidence of intra- and postoperative complications was also analyzed.Results: All procedures were successfully completed and none of the patients was lost to follow-up. Postoperative CT verified the successful removal of calcified protrusions. VAS and ODI scores improved significantly after surgery. Based on the Modified MacNab scale, >90% patients achieved good or excellent outcomes. There were no complications such as dural tear and infection. Seven patients had varying degrees of postoperative dysesthesia. One patient experienced recurrence of herniation within 1 week after operation; successful recovery was achieved after repeat PTED.Conclusions: Use of this ultrasonic osteotome for PTED facilitated effective removal of calcified disc protrusion, relieved nerve compression, and protected the adjacent neurovascular tissues. The instrument may help expand the indications for endoscopic surgery and avoid open surgery for some CLDH patients.

TNF-α-induced exosomal miR-146a mediates mesenchymal stem cell-dependent suppression of urethral stricture.

The effective treatment of urethral stricture remains a medical problem. The use of proinflammatory cytokines as stimuli to improve the reparative efficacy of mesenchymal stem cells (MSCs) towards damaged tissues represents an evolving field of investigation. However, the therapeutic benefits of this strategy in the treatment of urethral stricture remain unknown. Here, we enriched exosomes derived from human umbilical cord-derived MSCs pretreated with or without tumor necrosis factor alpha (TNF-α) to evaluate their therapeutic effects in an in vivo model of TGFß1-induced urethral stricture. Male Sprague-Dawley rats received sham (saline) or TGFß1 injections to urethral tissues followed by incisions in the urethra. Animals in the TGFß1 injection (urethral fibrosis) cohort were subsequently injected with vehicle control, or with exosomes derived from MSCs cultured with or without TNF-α. After 4 weeks, rats underwent ultrasound evaluation and, following euthanasia, urethral tissues were harvested for histological and molecular analysis. In vitro, the effects of MSC-derived exosomes on fibroblast secretion of collagen and cytokines were studied by enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (qRT-PCR), and western blot analysis. Exosomes derived from MSCs pretreated with TNF-α were more effective in suppressing urethral fibrosis and stricture than exosomes from untreated MSCs. We found that miR-146a, an anti-inflammatory miRNA, was strongly upregulated in TNF-α-stimulated MSCs and was selectively packaged into exosomes. Moreover, miR-146a-containing exosomes were taken up by fibroblasts and inhibited fibroblast activation and associated inflammatory responses, a finding that may underlie the therapeutic mechanism for suppression of urethral stricture. Inhibition of miR-146a in TNF-α-treated MSCs partially reduced antifibrotic effects and increased the release of proinflammatory factors of exosomes derived from these cells. Together these findings demonstrate that exosomes derived from TNF-α-treated MSCs are of therapeutic benefit in urethral fibrosis, suggesting that this strategy may have utility as an adjuvant therapy in the treatment of urethral stricture diseases.

Doppler ultrasonographic and clinical features of middle aortic syndrome.

OBJECTIVES: To discuss Doppler ultrasonographic and clinical features of middle aortic syndrome (MAS). MATERIALS AND METHODS: Doppler ultrasonographic images and clinical dates of 11 patients with MAS confirmed by angiography were retrospectively analyzed from January 2004 to September 2016. RESULTS: The median age of 11 patients was 10 years (1-39 years). Ten patients presented with hypertension, only 2 cases presented with symptomatic intermittent claudication, and 1 case presented with abdominal pain. The ultrasonographic features of 11 patients with MAS included: (a) Gray-scale image showed significant segmental narrowing of the aorta in 9 cases. (b) Color Doppler demonstrated aliasing in the suspicious narrowed vessels of all cases. (c) On Spectral Doppler image, peak systolic velocity in the location of aorta coarctation was significantly elevated (range, 2.3~4.8 m/s). When infrarenal aorta was involved, a tardus-parvus waveform was only seen in the distal aorta. When suprarenal or inter-renal aorta was involved, a tardus-parvus pattern was seen in the distal aorta as well as renal artery. CONCLUSIONS: Significant segmental narrowing and a tardus-parvus waveform are the important ultrasonographic features in patients with MAS, the latter may be more reliable. Doppler ultrasound can be used as a simple screening method, especially for children and adolescents suspected of having a vascular cause of refractory hypertension.

Internal Versus External Drainage With a Pancreatic Duct Stent For Pancreaticojejunostomy During Pancreaticoduodenectomy for Patients at High Risk for Pancreatic Fistula: A Comparative Study.

BACKGROUND: The aim of this study was to determine whether internal or external drainage with a pancreatic duct stent is the optimal pancreaticojejunostomy method to prevent pancreatic fistula (PF) after pancreaticoduodenectomy (PD) for subgroups of patients at high risk for PF. MATERIALS AND METHODS: A total of 495 patients who underwent PD were reviewed. Univariate and multivariate analyses were used to identify risk factors for PF after PD. We further compared the incidence of PF and outcomes between the internal and external drainage groups for subgroups of patients at high risk for PF. RESULTS: There was no difference in the incidence of complications according to the Clavien-Dindo classification or the rate of PF after PD in both groups (P = 0.961 and P = 0.505, respectively). The incidence of mortality was 3.8% in the internal drainage group and 3.9% in the external drainage group (P = 0.980). Univariate and multivariate analyses identified male gender (odds ratio [OR] = 2.93; 95% confidence interval [CI], 1.78-4.83; P = 0.000), pancreatic duct diameter (<3 mm) (OR = 2.58; 95% CI, 1.57-4.23; P = 0.000), and soft pancreatic texture (OR = 2.92; 95% CI, 1.71-4.98; P = 0.000) as independent risk factors for PF after PD. No differences in the incidence of PF for the subgroups of patients with one, two, or three risk factors were observed between the internal and external drainage groups (P = 0.334, P = 1.000, and P = 0.936, respectively). No differences in total complications, delayed gastric emptying, postpancreatectomy hemorrhage, biliary fistula, infection complications, reoperation, perioperative mortality, or postoperative hospital stay were noted. In addition, liquid loss and tube-related complications occurred in the external drainage group. CONCLUSIONS: Internal drainage is the optimal method to prevent PF after PD for subgroups of patients at high risk for PF because the surgical procedure is simple and prevents liquid loss and tube-related complications associated with external drainage. However, no differences in the incidence of PF and other complications after PD were observed between the two approaches.

Polycystic kidney and hepatic disease 1 gene mutations in von Meyenburg complexes: Case report.

Von Meyenburg complexes (VMCs) are a rare type of ductal plate malformation. We herein report two Chinese families with VMCs, and the suspicious gene mutation of this disease. Proband A was a 62-year-old woman with abnormal echographic presentation of the liver. She received magnetic resonance imaging (MRI) examination and liver biopsy, and the results showed she had VMCs. Histologically proved hepatocellular carcinoma was found 1 year after the diagnosis of VMCs. Proband B was a 57-year-old woman with intrahepatic diffuse lesions displayed by abdominal ultrasonography. Her final diagnoses were VMCs, congenital hepatic fibrosis, and hepatitis B surface e antigen-negative chronic hepatitis B after a series of examinations. Then, all the family members of both proband A and proband B were screened for VMCs by MRI or ultrasonography. The results showed that four of the 11 family members from two families, including two males and two females, were diagnosed with VMCs. DNA samples were extracted from the peripheral blood of those 11 individuals of two VMCs pedigrees and subjected to polymerase chain reaction amplification of the polycystic kidney and hepatic disease 1 (PKHD1) gene. Two different mutation loci were identified. Heterozygous mutations located in exon 32 (c.4280delG, p.Gly1427ValfsX6) in family A and exon 28 (c.3118C>T, p.Arg1040Ter) in family B were detected. We speculate that PKHD1 gene mutations may be responsible for the development of VMCs.

Effectiveness of Bi-Needle Technique (Hybrid Yeung Endoscopic Spine System/Transforaminal Endoscopic Spine System) for Percutaneous Endoscopic Lumbar Discectomy.

OBJECTIVE: The bi-needle technique is a new technique for percutaneous endoscopic lumbar discectomy. This technique combines the advantages of Yeung endoscopic spine system (YESS) and transforaminal endoscopic spine system (TESSYS) techniques. The aim of this study was to evaluate effectiveness of the bi-needle technique for percutaneous endoscopic lumbar discectomy and compare it with the TESSYS technique. METHODS: We reviewed 86 patients with single-level lumbar disc herniation treated by percutaneous endoscopic lumbar discectomy in our hospital from June 2013 to December 2015. Bi-needle technique was used in 49 patients (30 men, 19 women; average age 40.4 ± 5.2 years). TESSYS technique was used in 37 patients (19 men, 18 women; average age 42.8 ± 6.4 years). Clinical results were evaluated and compared between the 2 groups. RESULTS: Symptoms in both groups were significantly improved at the last follow-up (P < 0.01). There was no statistical difference in visual analog scale and lumbar Japanese Orthopaedic Association scores between bi-needle and TESSYS groups at last follow-up (P = 0.69 and P = 0.33, respectively). Operative time was shorter in the bi-needle group (P < 0.01). Recurrence rate and reoperation rate were lower in the bi-needle group (P = 0.04 and P = 0.03, respectively). Discitis was diagnosed in 2 patients in the TESSYS group. There were no patients with postoperative discitis in the bi-needle group. CONCLUSIONS: The bi-needle technique is safe and effective for treatment of lumbar disc herniation. Compared with TESSYS technique, operative time is shorter, and recurrence and reoperation rates are lower.

Clinical characteristics and neurologic recovery of patients with cervical spinal tuberculosis: should conservative treatment be preferred? A retrospective follow-up study of 115 cases.

OBJECTIVE: To present the clinical characteristics and prognostic factors of neurologic recovery in patients with cervical spinal tuberculosis (CST). METHODS: General description and multivariate analysis were used to detect possible predictors of the outcome of patients with neurologic deficit. Follow-up data were used to generate a Kaplan-Meier curve of neurologic recovery. RESULTS: Protective factors in neurologic recovery included less involved vertebrae, surgery, and higher Japanese Orthopaedic Association score before treatment; not shorter symptom duration was not a protective factor. Normal neurologic function was present in 30% of patients 6 months after treatment, in 56% of patients 12 months after treatment, and in 93% of patients 28 months after treatment. The cumulative complete neurologic recovery rates at 6 months, 12 months, and 28 months were 44%, 68%, and 91.7% in the surgery group and 16.7%, 38.8%, and 94.4% in the nonsurgery group. CONCLUSIONS: Surgery and Japanese Orthopaedic Association score before treatment are important predictors of neurologic recovery in patients with CST. A neurologic recovery curve could predict neurologic recovery in patients with CST and indicate in patients with neurologic deficit how long it will take to achieve complete neurologic recovery. The effect of surgery is quick, and the effect of conservative treatment is slower, but no difference in neurologic recovery was found in the long-term. Conservative treatment should be tried in every patient with CST with no obvious indication for surgery. In contrast to patients with tuberculosis without cervical spine involvement but with more complications, comprehensive conservative therapy should be preferred for patients with neurologic deficit to avoid unnecessary surgery and overtreatment and to conserve medical resources. Indications for surgical intervention for CST should be carefully selected.

[Osteogenetic capacity of cross-linked adjustable anti-tuberculosis drug sustained-release artificial composite].

OBJECTIVE: To explore the osteogenetic capacity of cross-linked adjustable anti-tuberculosis drug sustained-release artificial composite (TPB/SA-RFP/PLA). METHODS: The model of femur bone defect was established in rabbits.TPB/SA-RFP/PLA complex was implanted into defect parts in the experimental group while TPB/SA/PLA in the blank control group. At Weeks 4, 8 and 12, gross specimens received radiographic, histological and immunohistochemical examinations to determine the osteogenetic performance of TPB/SA-RFP/PLA. RESULTS: As compared with the control group, TPB/SA-RFP/PLA complex had excellent osteogenic capacities while the TPB/SA/PLA group had no obvious osteogenic difference. Lane-sandhu histological and radiographic ratings demonstrated significant difference between TPB/SA-RFP/PLA (8.3 ± 0.3) and blank groups (2.2 ± 0.4) (P < 0.05). And TPB/SA/PLA showed no significant intragroup significance (P > 0.05). Two groups immunohistochemical Alkaline phosphatase was strongly positive in two test groups and weakly positive in the control group. CONCLUSION: TPB/ SA-RFP/PLA has excellent profiles of bone conductivity and regeneration.And the incorporation of rifampin does not affect its osteogenetic capacity.

Brain-derived neurotrophic factor is up-regulated in severe acute cauda equina syndrome dog model.

To determine the level of brain-derived neurotrophic factor (BDNF) in experimental dog model of severe acute cauda equina syndrome, which was induced by multiple cauda equina constrictions throughout the entire lumbar (L), sacral (S) and coccygeal (Co) spinal cord and their central processes of the dorsal root ganglia neurons. Adult male mongrel dogs were randomly divided into 2 groups. The experiment group (n=4) was subjected to multiple cauda equina constrictions. The control group (n=4) was subjected to cauda equina exposure without constrictions. Level of BDNF in the spinal cord and the dorsal root ganglion cells (L7, S1-S3) was assessed 48 hours after multiple constrictions by immunohistochemical and histopathological analyses. 48 hours after multiple constrictions of cauda equina, up-regulation of BDNF within lumbosacral (L7-S3) spinal cord and dorsal root ganglion was observed in experimental group as compared to control group. Our result suggests that BDNF might play a role in the inflammatory and neuropathic pain as a result of multiple cauda equina constrictions. Regulation of BDNF level could potentially provide a therapy for treating cauda equina syndrome.

The prognostic value of elevated vascular endothelial growth factor in patients with osteosarcoma: a meta-analysis and systemic review.

BACKGROUND: Osteosarcoma is a primary malignancy of bone. Although new therapies continue to emerge, osteosarcoma-related morbidity and mortality remain high. Various studies have evaluated the prognostic value of VEGF levels in osteosarcoma patients, but they have yielded conflicting results. METHODS: The 5-year survival of each study was aggregated following a methodological assessment, and a systematic review of eligible studies with meta-analysis and univariate analysis was performed to quantitatively review the correlation of VEGF overexpression with 5-year survival in patients with osteosarcoma. RESULTS: A total of 387 patients in eleven papers were finally considered to be eligible for inclusion in our analysis. Aggregation of the 6 positive results in Kaplan-Meier curve showed a risk ratio of 2.84 (95% CI: 1.39-5.83, P = 0.004) associated with VEGF-positive conditions in comparison with VEGF-negative conditions, suggesting that there was significant association between VEGF positive and the 5-year mortality. But univariate analysis of eleven studies showed that there was a small inverse but not significant relationship between VEGF expression level and the 5-year survival of osteosarcoma patients, but stage III, neo-chemotherapy, the primary tumor location, osteoblastic histological subtype and the source of patients showed a significant impact on the 5-year survival of patients. CONCLUSIONS: The prognostic significance of VEGF expression in all its isoforms is still unknown based on the limited data available, but we find VEGF165 may play an important role. Future studies should examine the relationship between VEGF isoform expression and patients' survival and the relationship between VEGF isoform expression and EMMPRIN expression, which could be helpful for predicting the prognosis of patients with osteosarcoma. Once the conclusion of whether the VEGF and its isoforms playing a role in osteosarcoma were reached, it would help guide clinical decision-making regarding therapy and outcomes. In addition, we recommend a >25% positive staining of the cells as a VEGF-positive cut-off value in immunohistochemistry, since we find a relatively strict detecting method is likely to yield significant result in the 5-year survival of patients.

[Morphologic and apoptotic changes of cervical posterior longitudinal ligament fibroblasts in response to in vitro mechanical stretch].

OBJECTIVE: To investigate the effect of mechanical stretch force on the morphologic and apoptotic changes of fibroblasts derived from the OPLL (ossification of posterior longitudinal ligaments) patients. METHODS: The third passage cells were collected and subjected to 10% elongations cyclic mechanical stretching for 6 h and 24 h with Flexercell 4000(TM) strain unit. Their morphologic changes were observed and the post-stretching apoptotic rates quantified by flow cytometer. The gene expressions of alkaline phosphatase (ALP), collagen types I (COL I) and osteocalcin (OC) were examined. RESULTS: The treated cells were arranged along the vertical direction of force. Stretch force led to a slight increase of apoptosis rate at 6 h and a significant increase of apoptosis rate at 24 h. No significant difference in cellular senescence was observed between control group and treated group. The mRNA expressions of ALP, COL I and OC were positively up-regulated by cyclic stretch at 24 h. CONCLUSION: Stretching force can affect the cellular morphology, promote the osteogenic differentiation and enhance the cellular apoptosis.

[Biomechanical performance of different wires and cable fixation devices in posterior instrumentation for atlantoaxial instability].

OBJECTIVE: To compare the biomechanical performances of different wires and cable fixation devices in posterior instrumentation for atlantoaxial instability, and test the effect of different fixation strengths and fixation approaches on the surgical outcomes. METHODS: Six specimens of the atlantoaxial complex (C0-C3) were used to establish models of the normal complex, unstable complex (type II odontoid fracture) and fixed complex. On the wd-5 mechanical testing machine, the parameters including the strength and rigidity of anti-rotation, change and strength of stress, and stability were measured for the normal complex, atlantoaxial instability complex, the new type titanium cable fixation system, Atlas titanium cable, Songer titanium cable, and stainless wire. RESULTS: The strength and rigidity of anti-rotation, change and strength of stress, stability of flexion, extension and lateral bending of the unstable atlantoaxial complex fixed by the new double locking titanium cable fixation system were superior to those of the Songer or Atlas titanium cable (P<0.05) and medical stainless wire (P<0.05). Simultaneous cable fastening on both sides resulted in better fixation effect than successive cable fastening (P<0.05). Better fixation effect was achieved by fastening the specimen following a rest (P<0.05). CONCLUSIONS: The fixation effects can be enhanced by increased fastening strengths. The new type double locking titanium cable fixation system has better biomechanical performance than the conventional Songer and Atlas titanium cables. Fastening the unstable specimens after a rest following simultaneous fastening of the specimen on both sides produces better fixation effect.