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Current revision surgery to remove the infected interbody cage following transforaminal lumbar interbody fusion (TLIF) surgery is challenging and traumatic. The purpose of this study is to introduce a novel surgical technique to remove the infected interbody cage for chronic infection. Three patients with chronic infection following TLIF surgery underwent revision surgery. Instrumentations were removed and a spinal endoscope was obliquely inserted to the disc space through the initial annular breach. Under endoscope, the cage was found, released, turned around, and dragged to the posterior edge of the disc space. The cage was then removed without distracting the dural sac and nerve roots. For two cases, appropriately sized structural iliac bone grafts were used for interbody fusion without extra instrumentations. Using endoscope, the interbody cage was easy to identify and expose without disrupting the dural sac and nerve roots. With various endoscopic tools, the cage was easily released and removed. In this case series, the infected interbody cage was removed within thirty minutes without dural sac rupture and nerve root injury. The infection was controlled after the surgery, and the patients obtained good clinical outcomes. At 6-month follow-up, bony fusion was achieved in two patients who underwent interbody fusion. This endoscopy assisted technique simplified the revision surgery for chronic infection followed TLIF surgery, with the advantages of no disruption of the neural tissues, bright surgical field and complete disc debridement. [ABSTRACT FROM AUTHOR]

Purpose: Although signal intensity on T2W axial images is sensitive in detection of fatty infiltration to assess paraspinal muscle degeneration, it is affected by inhomogeneities of magnetic fields and individual variabilities. The purpose of this study was to propose reference adjusted signal measures on T2W axial images and determine their capacities in reflecting age-related lumbar paraspinal muscle degeneration. Methods: Lumbar MR images of 421 population-based subjects (177 men and 244 women, mean age 53.1 years, range 19.8–87.9 years) were studied. A custom software Spine Explore (Tulong 2.0) was used to automatically obtain paraspinal measurements of multifidus, erector spinae and psoas major. FCSA/TCSA was defined as functional cross-sectional area relative to total cross-sectional area of paraspinal muscle. Two new signal measures were canal-adjusted and cerebrospinal fluid (CSF)-adjusted signal, defined as the ratio between mean signal measurements and the mean signal of the canal and CSF. Results: The raw signal measurements of the paraspinal muscles were weakly correlated to age (r = 0.28–0.39, P < 0.001). When the signal of canal (r = 0.43–0.59, P < 0.001) or CSF (r = 0.45–0.61, P < 0.001) was used as reference, the correlations substantially increased. Signal measurements of three paraspinal muscles, adjusted or not, were strongly associated with Goutallier score (ρ = 0.60–0.65, P < 0.001) and FCSA/TCSA (r = −0.64 to −0.82, P < 0.001). Greater Goutallier score was associated with greater age (r = 0.38–0.60, P < 0.001), while Lumbar indentation value (LIV) not. Conclusion: On routine T2W axial MR images the adjusted signal measurements using an internal reference of CSF or canal can better reflect age-related degenerative changes in the paraspinal muscles. [ABSTRACT FROM AUTHOR]

A new kind of redox responsive nanoparticles was prepared through the modification and crosslinking reaction of xanthan gum. The nanoparticles had regular spherical shapes with diameters ranging from 110 to 180 nm. The nanoparticles showed good redox responsiveness. Doxorubicin (DOX) was loaded in the nanoparticles via ionic interaction with SO3-, for increasing the drug loading rate and avoiding drug leakage. The in vitro drug release could be controlled by pH and reduction conditions simulated to the internal environment of tumor cells. The nanoparticles were biocompatible and could be potentially applied as anti-cancer drug vehicles for targeted release. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the role of gravity in the sedimentation of lumbar spine nerve roots using magnetic resonance (MR) imaging of various body positions.Methods: A total of 56 patients, who suffered from back pain and underwent conventional supine lumbar spine MR imaging, were selected from sanmen hospital database. All the patients were called back to our hospital to perform MR imaging in prone position or lateral position. Furthermore, the sedimentation sign (SedSign) was determined based on the suspension of the nerve roots in the dural sac on cross-sectional MR images, and 31 cases were rated as positive and another 25 cases were negative.Results: The mean age of negative SedSign group was significantly younger than that of positive SedSign group (51.7 ± 8.7 vs 68.4 ± 10.5, P < 0.05). The constitutions of clinical diagnosis were significantly different between patients with a positive SedSign and those with a negative SedSign (P < 0.001). Overall, nerve roots of the vast majority of patients (48/56, 85.7%) subsided to the ventral side of the dural sac on the prone MR images, although that of 8 (14.3%) patients remain stay in the dorsal side of dural sac. Nerve roots of only one patient with negative SedSign did not settle to the ventral dural sac, while this phenomenon occurred in 7 patients in positive SedSign group (4% vs 22.6%, P < 0.001). In addition, the nerve roots of all the five patients subsided to the left side of dural sac on lateral position MR images.Conclusions: The nerve roots sedimentation followed the direction of gravity. Positive SedSign may be a MR sign of lumbar pathology involved the spinal canal. [ABSTRACT FROM AUTHOR]

Study Design: A cross-sectional magnetic resonance (MR) imaging study.Objective: To classify and characterize endplate defects using routine lumbar MR images and to determine associations of endplate defects with Modic changes (MCs) and disc degeneration.Summary Of Background Data: Previously, a cadaveric study revealed that endplate lesions were common and associated with back pain history. New in vivo approaches appropriate for clinical studies are needed to further this potentially important line of research on the clinical significance of endplate lesions, including their relation with MCs, disc degeneration, and back pain.Methods: Using a MRI archive, 1564 endplates of 133 subjects (59 men and 74 women, mean age 58.9 ± 11.9 years) with the presence of MCs were retrospectively collected from April of 2014 to June of 2015. On the basis of morphological characteristics, a protocol was proposed to identify three distinct types of endplate defects, including focal, corner, and erosive defects. The location, size, and distribution patterns of various endplate lesions were characterized. MCs and disc degeneration were measured to examine their associations with endplate defects.Results: Endplate defects were observed in 27.8% of endplates studied. Greater age was associated with the presence of endplate defects. Focal defects were the most common (13.5%), followed by erosive defects (11.1%) and corner defects (3.2%). Defect types also differed in size and distribution patterns. Endplate defects and MCs had similar distribution patterns in the lumbar spine. The presence of endplate defects were associated with the presence of MCs (odds ratio = 4.29, P < 0.001), and associated with less disc signal intensity and disc height, and greater disc bulging (P < 0.05).Conclusion: The three endplate defects identified on routine MR images appear to represent different pathologies and may play a key role in the pathogenesis of MCs. This classification system may facilitate clinical studies on endplate defects.Level Of Evidence: 4. [ABSTRACT FROM AUTHOR]

Background: While bisphosphonates (BPs) are commonly used in clinical treatment for osteoporosis, their roles on osteoporosis treatment for rheumatic patients remain unclear. We performed a meta-analysis to evaluate the efficacy of BPs on fractures prevention and bone mass preserving in rheumatic patients. Methodology/Principal Findings: We searched PubMed, EmBase, and the Cochrane Central Register of Controlled Trials for relevant literatures with a time limit of Jan. 6, 2012. All randomized clinical trials of BPs for adult rheumatic patients with a follow-up of 6 months or more were included. We calculated relative risks (RRs) for fractures and weighted mean difference (WMD) for percent change of bone mineral density (BMD). Twenty trials were included for analysis. The RR in rheumatic patients treated with BPs was 0.61 (95%CI [0.44, 0.83], P = 0.002) for vertebral fractures, and 0.49 (95%CI [0.23, 1.02], P = 0.06) for non-vertebral fractures. The WMD of BMD change in the lumbar spine was 3.72% (95%CI [2.72, 4.72], P<0.001) at 6 months, 3.67% (95%CI [2.84, 4.50], P<0.001) at 12 months, 3.64% (95%CI [2.59, 4.69], P<0.001) at 24 months, and 5.87% (95%CI [4.59, 7.15], P<0.001) at 36 months in patients using BPs, as compared with those treated with calcium, vitamin D or calcitonin. In subgroup analyses, rheumatic patients using BPs for osteoporosis prevention had greater WMD than those using BPs for treating osteoporosis at 6 months (4.53% vs. 2.73%, P = 0.05) and 12 months (4.93% vs. 2.91%, P = 0.01). Conclusions/Significance: In both short-term and middle-term, BPs can preserve bone mass and reduce the incidence of vertebral fractures in rheumatic patients, mainly for those who have GC consumption. The efficacy of BPs is better when using BPs to prevent rather than to treat osteoporosis in rheumatic patients. [ABSTRACT FROM AUTHOR]

Poly(N-isopropylacrylamide) was grafted on the surface of ultrafine silica beads through coupling reaction of semi-telechelic poly(N-isopropylacrylamide) (PNIPAm) and the silica beads. The synthetic route included the preparation of semi-telechelic PNIPAm with triethoxysilan group at the polymer chain end and the coupling reaction of the semi-telechelic PNIPAm with silica particles. The characterizations by infrared spectrometry, differential scanning calorimetry, scanning electron microscopy, and thermogravimetry analysis confirmed the formation of core-shell composites of silica-PNIPAm. The composites were thermo-sensitive and were used as a packing material in high-performance liquid chromatography (HPLC) for separating organic compound mixtures. The result indicated that satisfactory separations could be achieved by controlling the column temperature. [ABSTRACT FROM PUBLISHER]

Background: Annulus fibrosis (AF) defects have been identified as the primary cause of disc herniation relapse and subsequent disc degeneration following discectomy. Stem cell-based tissue engineering offers a promising approach for structural repair. Menstrual blood-derived mesenchymal stem cells (MenSCs), a type of adult stem cell, have gained attention as an appealing source for clinical applications due to their potential for structure regeneration, with ease of acquisition and regardless of ethical issues. Methods: The differential potential of MenSCs cocultured with AF cells was examined by the expression of collagen I, SCX, and CD146 using immunofluorescence. Western blot and ELISA were used to examine the expression of TGF-β and IGF-I in coculture system. An AF defect animal model was established in tail disc of Sprague-Dawley rats (males, 8 weeks old). An injectable gel containing MenSCs (about 1*106/ml) was fabricated and transplanted into the AF defects immediately after the animal model establishment, to evaluate its repairment properties. Disc degeneration was assessed via magnetic resonance (MR) imaging and histological staining. Immunohistochemical analysis was performed to assess the expression of aggrecan, MMP13, TGF-β and IGF-I in discs with different treatments. Apoptosis in the discs was evaluated using TUNEL, caspase3, and caspase 8 immunofluorescence staining. Results: Coculturing MenSCs with AF cells demonstrated ability to express collagen I and biomarkers of AF cells. Moreover, the coculture system presented upregulation of the growth factors TGF-β and IGF-I. After 12 weeks, discs treated with MenSCs gel exhibited significantly lower Pffirrmann scores (2.29 ± 0.18), compared to discs treated with MenSCs (3.43 ± 0.37, p < 0.05) or gel (3.71 ± 0.29, p < 0.01) alone. There is significant higher MR index in disc treated with MenSCs gel than that treated with MenSCs (0.51 ± 0.05 vs. 0.24 ± 0.04, p < 0.01) or gel (0.51 ± 0.05 vs. 0.26 ± 0.06, p < 0.01) alone. Additionally, MenSCs gel demonstrated preservation of the structure of degenerated discs, as indicated by histological scoring (5.43 ± 0.43 vs. 9.71 ± 1.04 in MenSCs group and 10.86 ± 0.63 in gel group, both p < 0.01), increased aggrecan expression, and decreased MMP13 expression in vivo. Furthermore, the percentage of TUNEL and caspase 3-positive cells in the disc treated with MenSCs Gel was significantly lower than those treated with gel alone and MenSCs alone. The expression of TGF-β and IGF-I was higher in discs treated with MenSCs gel or MenSCs alone than in those treated with gel alone. Conclusion: MenSCs embedded in collagen I gel has the potential to preserve the disc structure and prevent disc degeneration after discectomy, which was probably attributed to the paracrine of growth factors of MenSCs. [ABSTRACT FROM AUTHOR]

Due to suboptimal pain control under conventional local anesthesia, percutaneous endoscopic interlaminar discectomy is typically performed under general anesthesia. The purpose of this study was to develop a stepwise approach of local anesthesia for endoscopic interlaminar discectomy and evaluate its efficacy. A stepwise local anesthesia was developed, which mainly includes 3 steps: conventional local anesthesia from skin to laminae, epidural injection, and nerve root block. From June 2015 to May 2017, consecutive patients who underwent endoscopic interlaminar discectomy were included. Local anesthesia or general anesthesia was used based on patients' preference. Anesthetic effectiveness was evaluated as excellent, good, or poor, and adverse events were recorded. Hospitalization expense was compared between the 2 groups. Clinical outcomes were assessed using the Visual Analog Scale and the Oswestry Disability Index. There were 98 patients included in the study. Among them, 48 received stepwise local anesthesia and the other 50 received general anesthesia. In the stepwise local anesthesia group, 40 (83.3%) patients rated anesthetic effectiveness as excellent, 7 (14.6%) as good, and 1 (2.1%) as poor. Nine patients had complications that may be associated with local anesthesia, including dyspnea, temporary paresis of legs, and temporary worsened dysesthesia or numbness in legs. After surgery, the patients' leg pain and Oswestry Disability Index significantly improved in both groups. On average, hospitalization expense was approximately 20% less when local anesthesia was used, as compared with using general anesthesia. The stepwise local anesthesia can achieve satisfactory pain control and seems to be a good choice for endoscopic interlaminar discectomy. [ABSTRACT FROM AUTHOR]

Rice axillary meristems (AMs) are essential to the formation of tillers and panicle branches in rice, and therefore play a determining role in rice yield. However, the regulation of inflorescence AM development in rice remains elusive. In this study, we identified no spikelet 1-Dominant (nsp1-D), a sparse spikelet mutant, with obvious reduction of panicle branches and spikelets. Inflorescence AM deficiency in nsp1-D could be ascribed to the overexpression of OsbHLH069. OsbHLH069 functions redundantly with OsbHLH067 and OsbHLH068 in panicle AM formation. The Osbhlh067 Osbhlh068 Osbhlh069 triple mutant had smaller panicles and fewer branches and spikelets. OsbHLH067, OsbHLH068, and OsbHLH069 were preferentially expressed in the developing inflorescence AMs and their proteins could physically interact with LAX1. Both nsp1-D and lax1 showed sparse panicles. Transcriptomic data indicated that OsbHLH067/068/069 may be involved in the metabolic pathway during panicle AM formation. Quantitative RT-PCR results demonstrated that the expression of genes involved in meristem development and starch/sucrose metabolism was down-regulated in the triple mutant. Collectively, our study demonstrates that OsbHLH067, OsbHLH068, and OsbHLH069 have redundant functions in regulating the formation of inflorescence AMs during panicle development in rice. Author summary: Axillary meristems (AMs) generate branches and determine the inflorescence pattern, and further define the overall architecture of plants. In addition, they have great impacts on the tiller number and panicle size, and therefore significantly influence the seed number and yield of crops. Hence, understanding the molecular mechanism for AM development is of both scientific and application significance. Although some genes involved in panicle development of rice have been reported to date, the underlying mechanism remains largely unknown in rice. In this study, we reported that OsbHLH067, OsbHLH068, and OsbHLH069 redundantly regulate the formation of inflorescence AMs in rice. OsbHLH067, OsbHLH068, and OsbHLH069 were preferentially expressed in developing inflorescence AMs. Overexpression of OsbHLH069 resulted in sparse panicles. The Osbhlh067 Osbhlh068 Osbhlh069 triple mutant exhibited small panicles with fewer branches and spikelets. OsbHLH067/068/069 were found to interact with LAX1, which might be involved in the metabolism pathway and influence the gene expression related to panicle development. [ABSTRACT FROM AUTHOR]

Objectives: The integrity of endplate is important for maintaining the health of adjacent disc and trabeculae. Yet, pathological impacts of traumatic vertebra and endplate fractures were less studied using clinical approaches. This study aims to investigate their effects on the development of adjacent disc degeneration, segmental kyphosis, Modic changes (MCs), and high-intensity zones (HIZs). Materials and methods: Magnetic resonance (MR) images of patients with acute traumatic vertebral compression fractures (T11-L5) were studied. On MR images, endplate fractures were evaluated as present or absent. Disc signal, height, bulging area, sagittal Cobb angle, MCs, and HIZs were measured on baseline and follow-up MR images to study the changes of the disc in relation to vertebra fractures and endplate fractures. Results: Ninety-seven patients were followed up for 15.4 ± 14.0 months. There were 123 fractured vertebrae, including 79 (64.2%) with endplate fractures and 44 (35.8%) without. Both the adjacent and control discs decreased in signal and height over time (p < 0.001), and the disc adjacent to vertebral fractures had greater signal and height loss than the control disc (p < 0.05). In the presence of endplate fractures, the adjacent discs had greater signal decrease in follow-up (p < 0.05), as compared to those without endplate fractures. Sagittal Cobb angle significantly increased in segments with endplate fractures (p < 0.05). Vertebra fractures were associated with new occurrence of MCs in the fractured vertebra (p < 0.001) but not HIZs in the adjacent disc. Conclusions: Traumatic vertebral fractures were associated with accelerated adjacent disc degeneration, which appears to be further promoted by concomitant endplate fractures. Endplate fractures were associated with progression of segmental kyphosis. [ABSTRACT FROM AUTHOR]

Copolymers of poly(n-butyl methacrylate-co-glycidyl methacrylate) were prepared by a free radical polymerization. The structures of the copolymers were characterized. The copolymers could be added to a powder epoxy resin (E663) to form modified epoxy resins. It was found that toughness of the cured modified epoxy resins were greatly improved, impact strength increased 3 times and fracture elongation increased 20% compared to the cured unmodified E663 resin. This is because that the copolymers had epoxy groups and flexible butyl groups, the former were involved in cross-linking reaction of the E663, and the latter made contribution to the toughness improvement. [ABSTRACT FROM AUTHOR]

Objectives: The integrity of endplate is important for maintaining the health of adjacent disc and trabeculae. Yet, pathological impacts of traumatic vertebra and endplate fractures were less studied using clinical approaches. This study aims to investigate their effects on the development of adjacent disc degeneration, segmental kyphosis, Modic changes (MCs), and high-intensity zones (HIZs). Materials and methods: Magnetic resonance (MR) images of patients with acute traumatic vertebral compression fractures (T11-L5) were studied. On MR images, endplate fractures were evaluated as present or absent. Disc signal, height, bulging area, sagittal Cobb angle, MCs, and HIZs were measured on baseline and follow-up MR images to study the changes of the disc in relation to vertebra fractures and endplate fractures. Results: Ninety-seven patients were followed up for 15.4 ± 14.0 months. There were 123 fractured vertebrae, including 79 (64.2%) with endplate fractures and 44 (35.8%) without. Both the adjacent and control discs decreased in signal and height over time (p < 0.001), and the disc adjacent to vertebral fractures had greater signal and height loss than the control disc (p < 0.05). In the presence of endplate fractures, the adjacent discs had greater signal decrease in follow-up (p < 0.05), as compared to those without endplate fractures. Sagittal Cobb angle significantly increased in segments with endplate fractures (p < 0.05). Vertebra fractures were associated with new occurrence of MCs in the fractured vertebra (p < 0.001) but not HIZs in the adjacent disc. Conclusions: Traumatic vertebral fractures were associated with accelerated adjacent disc degeneration, which appears to be further promoted by concomitant endplate fractures. Endplate fractures were associated with progression of segmental kyphosis. [ABSTRACT FROM AUTHOR]

Study Design: An experimental study.Objective: The aim of this study was to determine the effect of polymethylmethacrylate (PMMA) augmentation on the adjacent disc.Summary Of Background Data: Vertebral augmentation with PMMA reportedly may predispose the adjacent vertebra to fracture. The influence of PMMA augmentation on the adjacent disc, however, remains unclear.Methods: Using a retroperitoneal approach, PMMA augmentation was performed for 23 rabbits. For each animal, at least one vertebra was augmented with 0.2 to 0.3 mL PMMA. The disc adjacent to the augmented vertebra and a proximal control disc were studied using magnetic resonance (MR) imaging, histological and molecular level evaluation at 1, 3, and 6 months postoperatively. Marrow contact channels in the endplate were quantified in histological slices and number of invalid channels (those without erythrocytes inside) was rated. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) was performed to determine disc cell apoptosis.Results: On MR images, the signal and height of the adjacent disc did not change 6 months after vertebral augmentation. Histological scores of the adjacent disc increased over time, particularly for the nucleus pulposus. The adjacent disc had greater nucleus degeneration score than the control disc at 3 months (5.7 vs. 4.5, P < 0.01) and 6 months (6.9 vs. 4.4, P < 0.001). There were more invalid marrow contact channels in the endplate of augmented vertebra than the control (43.3% vs. 11.1%, P < 0.01). mRNA of ADAMTS-5, MMP-13, HIF-1α, and caspase-3 were significantly upregulated in the adjacent disc at 3 and 6 months (P < 0.05 for all). In addition, there were more TUNEL-positive cells in the adjacent disc than in the control disc (43.4% vs. 24.0%, P < 0.05) at 6 months postoperatively.Conclusion: Vertebral augmentation can induce early degenerative signs in the adjacent disc, which may be due to impaired nutrient supply to the disc.Level Of Evidence: N/A. [ABSTRACT FROM AUTHOR]

Study Design: A radiological study of type II Modic changes (MCs).Objectives: The aim of this study was to determine the characteristics of type II MCs on fat suppression (FS) magnetic resonance (MR) images and its association with radiological disc degeneration.Summary Of Background Data: Type II MCs are common endplate signal changes on MR images. On the basis of limited histological samples, type II MCs are thought to be stable fat degeneration. FS technique on MR, which can quantify fat content, may be an alternative to explore the pathology of MCs. To date, however, the characteristics of type II MCs on FS sequence have not been studied.Methods: Lumbar MR images conducted in a single hospital during a defined period were reviewed to include those with type II MCs and FS images. On FS images, signal status of type II MCs was visually classified as suppressed or not-suppressed. Signal intensity of vertebral regions with and without MCs was measured quantitatively on T2-weighted (T2W) and FS images to calculate fat content index and validate the visual classification. Using image analysis program Osirix, MCs size and adjacent disc degeneration were measured quantitatively. Paired t-tests and logistic regressions were used to determine the associations studied.Results: Sixty-four lumbar MRIs were included and 150 endplates with type II MCs were studied. Although signal of 37 (24.7%) type II MCs was suppressed on FS images, that of 113 (75.3%) was not suppressed. The discs adjacent to type II MCs had lower signal intensity (0.13 ± 0.003 vs. 0.14 ± 0.004, P < 0.001), lesser disc height (9.73 ± 1.97 vs. 11.07 ± 1.99, P < 0.001) and greater bulging area (80.0 ± 31.4 vs. 61.3 ± 27.5 for anterior bulging, 33.72 ± 21.24 vs. 27.93 ± 12.79 for posterior bulging, and 113.7 ± 39.9 vs. 89.2 ± 35.2 for total bulging, P < 0.05) than normal controls. Type II MCs that were not suppressed on FS image were associated with greater age [odds ratio (OR) = 1.11, P < 0.001], lower height (OR = 0.94, P < 0.05), and greater posterior bulging (OR = 1.05, P < 0.001) at the adjacent disc.Conclusion: Signal of most type II MCs was not suppressed on FS MR images, suggesting that there are ongoing complicated pathologies. Type II MCs may not merely represent fat replacement.Level Of Evidence: 3. [ABSTRACT FROM AUTHOR]