Prevalence of Vertebral artery anomaly in upper cervical and its surgical implications: a systematic review.

BACKGROUND: The presence vertebral artery (VA) abnormalities in the upper cervical may be a potential cause of catastrophic complication in the posterior approach of the upper cervical spine surgery. The aim of this study was to demonstrate the real incidence of the V3 segment anomaly in patients who need upper cervical surgery, and tried to find out the risk factors of V3 segment anomaly to evaluate the necessary of computed tomographic angiography (CTA) for upper cervical surgery. METHOD: This systematic review was conducted following the preferred reporting items for systematic reviews and meta-Analyses (PRISMA). Retrospective studies and reports of case series involving human subjects with data on anomalies of vertebral artery in upper cervical spine were included. Data on the prevalence of persistent first intersegmental artery (PIA), fenestration of the VA (FA), posterior inferior cerebellar artery (PICA) were extracted. RESULTS: A total of 16 articles involving 5927 subjects met the inclusion criteria. The total incidence of V3 segment anomaly in the patients with bony abnormalities was 25.9% (74/286): PIA was 17.5%, FA was 6.6% and PICA was 1.8%. The total incidence of V3 segment anomaly in the patients without bony abnormalities was 2.7% (152/5671): PIA was 1.76%, FA was 0.4% and PICA was 0.5%. The total incidence of V3 segment anomaly in Asian population without bony abnormalities was 5.8%, while in European and American population was 0.8 and 0.6%, respectively. CONCLUSION: Patients with bone abnormalities are high risk factor for VA abnormalities, CTA is of paramount importance to evaluate the variant VA anatomy. However, regarding to the low incidence of V3 variation in normal population, we do not recommend preoperative CT angiography as mandatory part of preoperative.

The inhibition of microRNA-326 by SP1/HDAC1 contributes to proliferation and metastasis of osteosarcoma through promoting SMO expression.

Osteosarcoma (OS) is a malignant bone cancer lacking of effective treatment target when the metastasis occurred. This study investigated the implication of MicroRNA-326 in OS proliferation and metastasis to provide the clue for the treatment of metastatic OS. This study knocked down SP1 in MG63 and 143B cells and then performed Microarray assay to find the expression of miRNAs that were influenced by SP1. MTT, EdU, wound-healing and cell invasion assays were performed to evaluated cell proliferation and invasion. OS metastasis to lung was detected in a nude mice model. ChIP assay and DAPA were applied to determine the regulatory effect of SP1 and histone deacetylase 1 (HDAC) complex on miR-326 expression. Human OS tissues showed lowly expressed miR-326 but highly expressed Sp1 and HDAC. Sp1 recruited HDAC1 to miR-326 gene promoter, which caused the histone deacetylation and subsequent transcriptional inhibition of miR-326 gene. miR-326 deficiency induced the stimulation of SMO/Hedgehog pathway and promoted the proliferation and invasion of 143B and MG63 cells as well as the growth and metastasis in nude mice. SP1/HDAC1 caused the transcriptional inhibition of miR-326 gene by promoting histone deacetylation; miR-326 deficiency conversely stimulated SMO/Hedgehog pathway that was responsible for the proliferation and metastasis of OS.

Extracellular Vesicles Derived from Epidural Fat-Mesenchymal Stem Cells Attenuate NLRP3 Inflammasome Activation and Improve Functional Recovery After Spinal Cord Injury.

Spinal cord injury (SCI) is a devastating event which caused high mortality and morbidity. Recently, nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasome has been showed to act a critical t role in the secondly injury phase of SCI. In current study, we aimed to investigate the effect and underlying molecular mechanisms of extracellular vesicles derived from epidural fat (EF)- mesenchymal stem cells (MSCs) for the treatment of SCI. Ninety-six Sprague-Dawley rats were used for current study and randomly divided into four groups: sham group, SCI group, SCI + Saline group, SCI + Extracellular vesicles group. Basso-Beattie-Bresnahan (BBB) scores was applied to evaluate the neurological functional recovery. Cresyl violet-stained was conducted evaluate the protective effect of EF-MSCs-Extracellular vesicles on lesion volume after SCI. ELISA, immunohistochemistry assay, TUNEL assay and western blotting were conducted to investigate the underlying molecular mechanisms. Our results demonstrated that the administration of EF-MSCs-Extracellular vesicles via tail vein injection improved neurological functional recovery and reduced the lesion volume after SCI. And systemic administration of EF-MSCs-Extracellular vesicles significantly inhibited NLRP3 inflammasome activation and reduced the expression of inflammatory cytokines. Additionally, the expression levels of proapoptotic protein Bax was decreased and antiapoptotic Bcl-2 was upregulated with the treatment of EF-MSCs-Extracellular vesicles after SCI. In summary, in current study, we demonstrated for the first time that the EF-MSCs-Extracellular vesicles can improve neurological functional recovery after SCI, and the underlying molecular mechanisms may partly through the inhibition of NLRP3 inflammasome activation.

Exosomes Derived from miR-126-modified MSCs Promote Angiogenesis and Neurogenesis and Attenuate Apoptosis after Spinal Cord Injury in Rats.

Spinal cord injury (SCI) is a devastating neurological event that results in incomplete or complete loss of voluntary motor and sensory function. Until recently, there has been no effective curative strategy for SCI. Our previous study showed that microRNA (miR)-126 promoted angiogenesis and attenuated inflammation after SCI; however, the effect of miR-126-based treatment is limited because of the low efficiency of miR delivery in vivo. Recently, accumulating evidence has indicated that exosomes can serve as a valuable therapeutic vehicle for miR delivery to the central nervous system (CNS). Thus, the present study aimed to investigate whether exosomes derived from mesenchymal stem cells (MSCs) can be used to deliver miR-126 to treat SCI. In this study, we found that MSCs can load miR-126 into secreted exosomes. In a rat model of SCI, exosomes transferred miR-126 to the injured site of the spinal cord, reduced the lesion volume and improved functional recovery after SCI. Additionally, miR-126-loaded exosomes promoted angiogenesis post-SCI. Moreover, the administration of miR-126 exosomes promoted neurogenesis and reduced cell apoptosis after SCI. In vitro, we observed that exosomes derived from miR-126-modified MSCs promoted the angiogenesis and migration of human umbilical venous endothelial cells (HUVECs) by inhibiting the expression of Sprouty-related EVH1 domain-containing protein 1 (SPRED1) and phosphoinositide-3-kinase regulatory subunit 2 (PIK3R2). In conclusion, our study demonstrated that exosomes derived from MSCs transfected with miR-126 may promote angiogenesis and neurogenesis, inhibit apoptosis and promote functional recovery after SCI. These findings suggest that exosomes derived from miR-126-modified MSCs may serve as a novel potential therapeutic strategy for treating SCI.

Second Sacral Alar Screw Fixation: Anatomic Study of Three-Dimensional Computed Tomography and Case Report.

OBJECTIVE: S2 alar screw would be an alternative choice without breaking the sacroiliac joint. The aim of this study was to measure radiographic parameters for optimal placement of posterior S2 alar screw for instrumentation and fusion. METHODS: Three-dimensional computed tomography scans of the pelvis of 60 normal adults were used to map the S2 alar screw. Entry point was typically chosen lateral and superior to the S2 dorsal foramen. Ideal S2 alar screw trajectories were explored by rotating the three-dimensional pelvis, while ensuring trajectories were of maximum length and width. After identification of an optimal trajectory, related linear anatomic parameters and sagittal and transverse angles were determined. RESULTS: Ideal S2 alar screw trajectories were identified in each computed tomography scan. According to this morphometric study, trajectories for female patients were more lateral in the transverse plane (female 33.73 ± 5.99° vs. male 29.82 ± 4.11°, P < 0.001). Maximal length of trajectory in male patients was significantly longer than in female patients (female 40.82 ± 4.29 mm vs. male 43.42 ± 4.02 mm, P = 0.001). Fourteen S2 alar screws were used in 7 patients with high-grade spondylolisthesis, scoliosis, or nonunion at lumbosacral site. No complications occurred during S2 alar screw placement. One S2 screw failed owing to severe local osteoporosis. No patient developed local pain or wound-related problems. CONCLUSIONS: S2 alar screw is an alternative sacral fixation point to provide additional biomechanical stability of lumbosacral constructs. A trajectory with maximum length through the S2 ala can be determined using three-dimensional computed tomography.

Systemic Administration of Exosomes Released from Mesenchymal Stromal Cells Attenuates Apoptosis, Inflammation, and Promotes Angiogenesis after Spinal Cord Injury in Rats.

Spinal cord injury (SCI) is one of the most common devastating injuries, which causes permanent disabilities such as paralysis and loss of movement or sensation. The precise pathogenic mechanisms of the disease remain unclear, and, as of yet, there is no effective cure. Mesenchymal stem cells (MSCs) show promise as an effective therapy in the experimental models of SCI. MSCs secrete various factors that can modulate a hostile environment, which is called the paracrine effect. Among these paracrine molecules, exosome is considered to be the most valuable therapeutic factor. Thus, exosomes from MSCs (MSCs-exosomes) can be a potential candidate of therapeutic effects of stem cells. The present study was designed to investigate the effect of whether systemic administration of exosomes generated from MSCs can promote the function recovery on the rat model of SCI in vivo. In the present study, we observed that systemic administration of MSCs-exosomes significantly attenuated lesion size and improved functional recovery post-SCI. Additionally, MSCs-exosomes treatment attenuated cellular apoptosis and inflammation in the injured spinal cord. Expression levels of proapoptotic protein (Bcl-2-associated X protein) and proinflammatory cytokines (tumor necrosis factor alpha and interleukin [IL]-1ß) were significantly decreased after MSCs-exosomes treatment, whereas expression levels of antiapoptotic (B-cell lymphoma 2) and anti-inflammatory (IL-10) proteins were upregulated. Further, administration of MSCs-exosomes significantly promoted angiogenesis. These results show, for the first time, that systemic administration of MSCs-exosomes attenuated cell apoptosis and inflammation, promoted angiogenesis, and promoted functional recovery post-SCI, suggesting that MSCs-exosomes hold promise as a novel therapeutic strategy for treating SCI.

[Operative results and prognosis of thoracic spinal stenosis].

OBJECTIVE: To discuss the clinical properties, operative results of thoracic spinal stenosis and factors correlating with prognosis. METHODS: From September 1992 to January 2001, 16 patients who suffered from thoracic spinal stenosis caused by degeneration, ossified ligamentum flavum, diffuse idiopathic hyperostosis and trauma, were decompressed by operation. The operative method was selected according to the compressed position of spinal cord. All patients were followed up 6 months to 9 years. The pain severity, ambulatory status and paraplegia index were compared between before operation and after operation. The correlation between prognosis and ages, the length of stenosis and the duration of disease was studied. RESULTS: The results of Wilcoxon Signed Ranks Test show significant difference in pain severity, ambulatory status and paraplegia index between before operation and after operation (P < 0.01). The results of partial correlation analyzing show that only the duration of disease was correlated with paraplegia index (P < 0.05). CONCLUSION: Thoracic spinal stenosis frequently develops in the lower-thoracic segments in middle and old aged men. Decompression by operation early can achieve a good clinical result. Duration of disease affects the prognosis.