Short shaft ratio: A novel predictor for dural ossification in patients with ossification of the ligamentum flavum.

Background: Dural ossification (DO) is strongly correlated with an increased incidence of complications during the surgery for the patients with thoracic ossification of the ligamentum flavum (OLF). Some methods for predicting DO have emerged, but the accuracy remains to be improved. We aimed to find a more accurate way to predict the appearance of DO. Methods: Retrospective study was adopted in this study. According to the intraoperative findings, ninety-one patients with thoracic OLF were ultimately included and divided into two groups based on the presence or absence of DO. Patient characteristics and radiographic data were recorded. The residual area ratio (RAR, residual area/cross-section area of normal spinal canal × 100%) and the short shaft ratio (SSR, the length of short shaft of the ellipse-like shape/the length of the spinal canal × 100%) were measured and calculated by 2 independent observers, followed by statistical analysis. The receiver operating characteristic curve was used to evaluate the accuracy of the SSR and RAR in predicting DO. Results: No significant differences were found in sex, age and BMI between the DO group and the non-DO group. The mean RAR (and standard deviation) in the Non-DO group (62.6% ± 10.2%) was significantly higher (p < 0.001) than that in the DO group (46.1% ± 10.5%). The mean SSR (and standard deviation) in the Non-DO group (61.6% ± 6.0%) was significantly higher (p < 0.001) than that in the DO group (43.6% ± 9.2%). The receiver operating characteristic curve indicated that the SSR and RAR can be used as the efficient indicators to identify DO, and the SSR has a higher accuracy in indicating the presence of DO, with a cutoff value of ＜48.71% (sensitivity of 100% and specificity of 85.0%). Conclusion: The SSR can be used as a supplement parameter to traditional methods to predict DO, and it could be a better predictor. And, compared with bilateral and bridged type, unilateral type of OLF was more likely to develop DO with a larger SSR.

ASXL1 interacts with the cohesin complex to maintain chromatid separation and gene expression for normal hematopoiesis.

ASXL1 is frequently mutated in a spectrum of myeloid malignancies with poor prognosis. Loss of Asxl1 leads to myelodysplastic syndrome-like disease in mice; however, the underlying molecular mechanisms remain unclear. We report that ASXL1 interacts with the cohesin complex, which has been shown to guide sister chromatid segregation and regulate gene expression. Loss of Asxl1 impairs the cohesin function, as reflected by an impaired telophase chromatid disjunction in hematopoietic cells. Chromatin immunoprecipitation followed by DNA sequencing data revealed that ASXL1, RAD21, and SMC1A share 93% of genomic binding sites at promoter regions in Lin-cKit+ (LK) cells. We have shown that loss of Asxl1 reduces the genome binding of RAD21 and SMC1A and alters the expression of ASXL1/cohesin target genes in LK cells. Our study underscores the ASXL1-cohesin interaction as a novel means to maintain normal sister chromatid separation and regulate gene expression in hematopoietic cells.

Anterior cervical discectomy and fusion versus anterior cervical corpectomy and fusion in multilevel cervical spondylotic myelopathy: A meta-analysis.

BACKGROUND: Both anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF) are used to treat multilevel cervical spondylotic myelopathy (mCSM); however, which one is better treatment for mCSM remains considerable controversy. A meta-analysis was performed to compare clinical outcomes, radiographic outcomes, and surgical outcomes between ACDF and ACCF in treatment for mCSM. METHODS: An extensive search of literature was performed in Pubmed/MEDLINE, Embase, the Cochrane library, CNKI, and WANFANG databases on ACDF versus ACCF treatment for mCSM from January 2011 to August 2016. The following variables were extracted: length of hospital stay, blood loss, operation time, Japanese Orthopedic Association (JOA) scores, Neck Disability Index (NDI) score, fusion rate, Cobb angles of C2 to C7, dysphagia, hoarseness, C5 palsy, infection, cerebral fluid leakage, donor site pain, epidural hematoma, graft subsidence, graft dislodgment, pseudoarthrosis, and total complications. Data analysis was conducted with RevMan 5.3 and STATA 12.0. RESULTS: A total of 8 studies containing 878 patients were included in our study. The results showed that ACDF is better than ACCF in the angle of C2 to C7 at the final follow-up (P < 0.00001, standardized mean difference = 4.76 [3.48, 6.03]; heterogeneity: P = 0.17, I = 43%), C5 plasy (P = 0.02, odds ratio [OR] 0.42, 95% confidence interval [CI] 0.21, 0.86; heterogeneity: P = 0.52, I = 0%), blood loss (P < 0.00001, standardized mean difference = -53.12, 95% CI -64.61, -41.64; heterogeneity: P = 0.29, I = 20%), fusion rate (P = 0.04, OR 2.54, 95% CI 1.05, 6.11; heterogeneity: P = 0.29, I = 20%), graft subsidence (P = 0.004, OR 0.11, 95% CI 0.02, 0.48; heterogeneity: P = 0.94, I = 0%), and total complications (P = 0.0009, OR 0.56, 95% CI 0.40, 0.79; heterogeneity: P = 0.29, I = 18%).However, there are no significant differences in length of hospital stay, operation time, JOA scores, NDI scores, preoperative angle of C2 to C7, dysphagia, hoarseness, infection, cerebral fluid leakage, donor site pain, epidural hematoma, graft dislodgment, and pseudoarthrosis (all P > 0.05). CONCLUSIONS: Based on our meta-analysis, our results suggest that both ACDF and ACCF are good plans in clinical outcomes; however, ACDF is a better choice in radiographic outcomes and total complications for the treatment of multilevel CSM.