ABSTRACT
Blood vessel growth is regulated by angiogenic and angiostatic CXC chemokines, and radiation is a vasculogenic stimulus. We investigated the effect of radiation on endothelial cell chemokine signaling, receptor expression, and migration and apoptosis. Human umbilical vein endothelial cells were exposed to a single fraction of 0, 5, or 20 Gy of ionizing radiation (IR). All vasculogenic chemokines (CXCL1-3/5-8) increased 3-13-fold after 5 or 20 Gy IR. 20 Gy induced a marked increase (1.6-4-fold) in angiostatic CXC chemokines. CXCR4 expression increased 3.5 and 7-fold at 48 h after 5 and 20 Gy, respectively. Bone marrow progenitor cell chemotaxis was augmented by conditioned media from cells treated with 5 Gy IR. Whereas 5 Gy markedly decreased intrinsic cell apoptosis (0 Gy=16%+/-3.6 vs. 5 Gy=4.5%+/-0.3), 20 Gy increased it (21.4%+/-1.2); a reflection of pro-survival angiogenic chemokine expression. Radiation induces a dose-dependent increase in pro-angiogenic CXC chemokines and CXCR4. In contrast, angiostatic chemokines and apoptosis were induced at higher (20 Gy) radiation doses. Cell migration improved significantly following 5 Gy, but not 20 Gy IR. Collectively, these data suggest that lower doses of IR induce an angiogenic cascade while higher doses produce an angiostatic profile.
Subject(s)
Angiostatic Proteins/metabolism , Chemokines, CXC/metabolism , Endothelial Cells/radiation effects , Gene Expression Regulation/radiation effects , Angiogenesis Inducing Agents/metabolism , Angiostatic Proteins/genetics , Angiostatic Proteins/radiation effects , Apoptosis/radiation effects , Cell Line , Cell Movement/radiation effects , Dose-Response Relationship, Immunologic , Dose-Response Relationship, Radiation , Endothelial Cells/immunology , Flow Cytometry , Humans , Immunoblotting , RNA, Messenger/metabolism , Receptors, CXCR4/metabolism , Receptors, CXCR4/radiation effects , Signal Transduction/radiation effectsABSTRACT
BACKGROUND CONTEXT: Anterior fusion through an open thoracotomy restores kyphosis more reliably than posterior techniques in patients with thoracic adolescent idiopathic scoliosis (AIS). Video-assisted thoracoscopic spinal fusion and instrumentation (VATS) minimizes the morbidity, from soft tissue and muscle dissection that accompanies traditional open thoracotomy. To our knowledge, there has not been a comprehensive analysis of VATS with respect to radiographic and clinical outcomes in the sagittal plane. PURPOSE: To measure the radiographic and clinical outcomes after VATS with emphasis on the sagittal plane. STUDY DESIGN/SETTING: A retrospective, radiographic review of 26 consecutive patients with Lenke type-I AIS who underwent VATS. METHODS: Radiographs of 26 consecutive patients with Lenke type-I AIS curves operated by a single surgeon were retrospectively reviewed after VATS. Sagittal and coronal parameters were compared with reported data for open anterior and posterior procedures. RESULTS: There was an increase in kyphosis from baseline to final follow-up by 6.6 degrees (25%) from T2 to T12 (p<.0001), 8.7 degrees (50%) from T5 to T12 (p<.0001), and 8 degrees (54%) in the instrumented segment (p<.0001). Junctional kyphosis did not occur. No differences were detected in sagittal measurements between the first postoperative erect and the final radiographs. Patients experienced significant improvements from baseline to 2 years in Scoliosis Research Society-22 Health-Related Quality-of-Life Outcome Questionnaire scores (p<.0001). CONCLUSIONS: Video-assisted thoracoscopic spinal fusion and instrumentation, in agreement with results reported for open anterior instrumentation, reliably restores or increases thoracic kyphosis while preserving junctional alignment in thoracic AIS.
Subject(s)
Scoliosis/surgery , Spinal Fusion/instrumentation , Spinal Fusion/methods , Thoracic Surgery, Video-Assisted/instrumentation , Thoracic Surgery, Video-Assisted/methods , Adolescent , Child , Female , Humans , Male , Treatment OutcomeABSTRACT
Treatment of high-grade isthmic and dysplastic spondylolisthesis in children and adolescents remains a challenge. Surgical treatment of spondylolisthesis has been recommended in adolescents with pain refractory to nonoperative modalities, slippage progression, or > 50% slippage on presentation. Controversy exists as to the optimal surgical approach for high-grade spondylolisthesis. In this report, we describe 5 cases of high-grade isthmic and dysplastic spondylolisthesis in adolescents and review the literature on surgical treatment for this entity. Operative records, charts, x-rays, and Scoliosis Research Society outcome questionnaires (SRS-22) were retrospectively evaluated for 5 consecutive patients diagnosed with and treated for high-grade spondylolisthesis. Each patient received treatment consisting of decompression, reduction, and circumferential fusion with transpedicular and segmental fixation from a posterior approach. Two patients had transient L5 nerve root deficit, which resolved within 3 months. Reduction benefits include a decrease in shear stresses (and resulting decreased rates of postoperative pseudarthrosis and slip progression), restoration of sagittal alignment and lumbosacral spine balance, and improvement in clinical deformity.