Comparison of blood loss between tranexamic acid-soaked absorbable Gelfoam and topical retrograde injection via drainage catheter plus clamping in cervical laminoplasty surgery.

BACKGROUND: To compare the safety and efficacy of tranexamic acid (TXA)-soaked absorbable Gelfoam and the retrograde injection of TXA through a drain with drain-clamping in degenerative cervical laminoplasty patients. METHODS: Patients were assigned into either TXA retrograde injection (TXA-RI), TXA-soaked absorbable Gelfoam (TXA-Gel), or control groups. The demographics, operative measurements, volume and length of drainage, length of hospital stay, complete blood cell count, coagulopathy, postoperative complications, and blood transfusion were recorded. RESULTS: We enrolled 133 patients, with 44, 44, and 45 in the TXA-RI, TXA-Gel, and control groups, respectively. The baseline characteristics did not differ significantly among the three groups. The TXA-RI group exhibited a lower volume and length of postoperative drainage compared to the TXA-Gel and control groups (126.60 ± 31.27 vs. 156.60 ± 38.63 and 275.45 ± 75.27 mL; 49.45 ± 9.70 vs 58.70 ± 10.46 and 89.31 ± 8.50 hours, all P < 0.01). The TXA-RI group also had significantly shorter hospital stays compared to the control group (5.31 ± 1.18 vs 7.50 ± 1.25 days, P < 0.05) and higher hemoglobin and hematocrit levels (12.58 ± 1.67 vs 11.28 ± 1.76 g/dL; 36.62 ± 3.66% vs 33.82 ± 3.57%, both P < 0.05) at hospital discharge. In the TXA-RI and TXA-Gel groups, the D-dimmer (DD) and fibrinogen (FIB) were significantly lower than those in the control group after surgery (P < 0.05). None of the patients required blood transfusion. No complications, including thromboembolic events, were reported. CONCLUSION: Topical retrograde injection of TXA through a drain with drain-clamping at the conclusion of unilateral posterior cervical expansive open-door laminoplasty may effectively reduce postoperative blood loss and the length of hospital stays without increasing postoperative complications.

Combined topical and intravenous administration of tranexamic acid further reduces postoperative blood loss in adolescent idiopathic scoliosis patients undergoing spinal fusion surgery: a randomized controlled trial.

BACKGROUND: To indicate whether combined topical and intravenous (IV) administration of tranexamic acid (TXA) could further reduce the blood loss after surgery for adolescent idiopathic scoliosis (AIS) compared with IV-TXA alone. METHODS: Ninety AIS patients who underwent posterior spinal fusion were prospectively randomized to combined group (IV + topical- TXA group) and IV-TXA alone group. TXA was infused at a loading dose of 1 g from the beginning of the surgery with a maintenance dose of 10 mg/kg/h until the wound was closed. In the combined group, 2 g TXA was injected retrogradely through a drain, while an equivalent amount of normal saline was injected in the IV-TXA alone group. The drain tube was clamped for 2 h in both groups. The amount of wound drainage and transfusion rates were analyzed. RESULTS: The drainage volume and duration of drain were significantly lower in the combined group compared with that in the IV-TXA alone group (372.0 ± 129.7 mL vs. 545.2 ± 207.7 mL, P < 0.001;64.7 ± 13.9 h vs. 82.0 ± 12.5 h, P < 0.001). Postoperative length of hospital stay was also significantly shorter in the combined group (6.5 ± 1.51 days vs. 7.95 ± 1.44 days, P < 0.05). Transfusion and complication rates were comparable between the two groups . CONCLUSIONS: IV injection of TXA combined with retrograde injection of TXA into a drain and clamping it for 2 h could further reduce the total volume of drainage in AIS patients who underwent spinal fusion surgery. TRIAL REGISTRATION: Chinese Clinical Trial Registry: ChiCTR1900024177 , Registered 29 June 2019, http://www.chictr.org.cn/showproj.aspx?proj=40214.

LncRNA-SULT1C2A regulates Foxo4 in congenital scoliosis by targeting rno-miR-466c-5p through PI3K-ATK signalling.

Congenital scoliosis (CS) is the result of anomalous vertebrae development, but the pathogenesis of CS remains unclear. Long non-coding RNAs (lncRNAs) have been implicated in embryo development, but their role in CS remains unknown. In this study, we investigated the role and mechanisms of a specific lncRNA, SULT1C2A, in somitogenesis in a rat model of vitamin A deficiency (VAD)-induced CS. Bioinformatics analysis and quantitative real-time PCR (qRT-PCR) indicated that SULT1C2A expression was down-regulated in VAD group, accompanied by increased expression of rno-miR-466c-5p but decreased expression of Foxo4 and somitogenesis-related genes such as Pax1, Nkx3-2 and Sox9 on gestational day (GD) 9. Luciferase reporter and small interfering RNA (siRNA) assays showed that SULT1C2A functioned as a competing endogenous RNA to inhibit rno-miR-466c-5p expression by direct binding, and rno-miR-466c-5p inhibited Foxo4 expression by binding to its 3' untranslated region (UTR). The spatiotemporal expression of SULT1C2A, rno-miR-466c-5p and Foxo4 axis was dynamically altered on GDs 3, 8, 11, 15 and 21 as detected by qRT-PCR and northern blot analyses, with parallel changes in Protein kinase B (AKT) phosphorylation and PI3K expression. Taken together, our findings indicate that SULT1C2A enhanced Foxo4 expression by negatively modulating rno-miR-466c-5p expression via the PI3K-ATK signalling pathway in the rat model of VAD-CS. Thus, SULT1C2A may be a potential target for treating CS.

Correlation between severity of adolescent idiopathic scoliosis and pulmonary artery systolic pressure: a study of 338 patients.

PURPOSE: Study of patients with adolescent idiopathic scoliosis. OBJECTIVE: To examine the correlation between pulmonary arterial pressure and coronal Cobb angle of idiopathic scoliosis. METHODS: A total of 338 patients (82.8 % female) with idiopathic scoliosis (average age 15.6 years; range 14-20 years) were included. Preoperatively, the coronal Cobb angle of curvature and the apex location and direction were determined from radiographic records. Tricuspid regurgitation velocity (TRV) and inferior vena cava diameter were also measured using Doppler echocardiography. Pulmonary arterial systolic pressure (sPAP) was calculated from the TRV according to the modified Bernoulli equation and correlations between sPAP and the features of scoliosis were identified by statistical analysis. RESULTS: Among the 338 patients, there were 305 thoracic curves, 276 (90.5 %) of which were right curves, and 265 thoracolumbar/lumbar curves. sPAP varied from 5.0 to 37.6 mmHg. Pulmonary hypertension could not be excluded in the case of one patient. A mild correlation (Spearman test, correlation coefficient = 0.187, P = 0.001) between sPAP and coronal Cobb angle of the main thoracic (MT) curves was identified. Correlations between sPAP and the degree of other curves were not significant. Patients with sPAP >20 mmHg also had larger thoracic curve angles (mean MT 42.16° vs. 52.45°; U test, P = 0.002). There were no differences in sPAP levels between patients with right and left thoracic curves. CONCLUSIONS: A mild positive correlation was identified between sPAP and the coronal Cobb angle of the MT curves. There was no relationship between sPAP and the direction of the curvature.

Does intraoperative cell salvage system effectively decrease the need for allogeneic transfusions in scoliotic patients undergoing posterior spinal fusion? A prospective randomized study.

PURPOSE: To determine the safety and efficacy of intraoperative cell salvage system in decreasing the need for allogeneic transfusions in a cohort of scoliosis patients undergoing primary posterior spinal fusion with segmental spinal instrumentation. METHODS: A total of 110 consecutive scoliosis patients undergoing posterior instrumented spinal fusion were randomized into two groups according to whether a cell saver machine for intraoperative blood salvage was used or not. Data included age, body mass index, perioperative hemoglobin levels, surgical time, levels fused, perioperative estimated blood loss, perioperative transfusions and incidence of transfusion-related complications. A Chi-square test and t tests were performed for intraoperative and perioperative allogeneic transfusion between groups. A regression analysis was performed between selected covariates to investigate the predictive factors of perioperative transfusion. RESULTS: Perioperative allogenic blood transfusion rate was lower in the cell saver group (14.5 versus 32.7%, p = 0.025). Mean intraoperative red blood cell transfusion requirement was also lower (0.21 U/pt versus 0.58 U/pt, p = 0.032). A multivariate analysis demonstrated that no. of fused segments (OR: 1.472; p = 0.005), preoperative hemoglobin level (OR: 0.901; p = 0.001), and the use of cell saver system (OR: 0.133; p = 0.003) had a trend toward significance in predicting likelihood of transfusion. CONCLUSIONS: Cell saver use significantly reduces the need for allogeneic blood in spine deformity surgery, particularly in patients with low preoperative hemoglobin or longer operation time. This study confirms the utility of routine cell saver use during PSF with segmental spinal instrumentation for scoliosis patients.

An analysis of thoracic cage deformities and pulmonary function tests in congenital scoliosis.

PURPOSE: To determine: (1) the relationship of thoracic cage parameters and preoperative pulmonary function tests (PFTs) in congenital scoliosis (CS) patients. (2) if patients with rib deformity have greater impairment of PFTs than those without rib deformity. METHODS: A total of 218 patients with CS and pulmonary dysfunction (FVC < 80 %) were conducted in one spine center between Jan 2009 and Mar 2013. The demographic distribution, medical records, PFTs and radiographs of all patients were collected. The association of PFTs and thoracic cage deformities was analyzed. RESULTS: In total, 143 patients (65.6 %) had a clinically relevant impairment of pulmonary function. They had smaller BMI, larger thoracic transverse and anteroposterior diameter, more thorax height, scoliotic angle and number of involved vertebra than no clinically impairment. PFTs were negative correlation significantly with scoliotic angle, number of involved vertebra and thoracic sagittal diameter, while thorax height is significant positive. The T1-12 height was significant positive correlation with age, stature, weight, thoracic transverse and sagittal longitudinal diameter, while negative correlation with scoliotic curve, number of involved vertebra, as well as kyphotic angle. PFTs do not correlate with T1-12 height, but significantly associated with the rib anomalies. The FVC and FEV1 were significantly lower in patients with rib anomalies than without rib anomalies. There was no association between the pulmonary function and the location of rib deformities. CONCLUSIONS: PFTs correlate significantly with scoliotic angle, number of involved vertebra, thoracic sagittal diameter, and thorax height. PFTs were significantly lower in patients with rib anomalies, particular to the patients with fused rib.

Evaluation of quality of life in adolescent idiopathic scoliosis with different distal fusion level: a comparison of L3 versus L4.

STUDY DESIGN: Retrospective case-control study. OBJECTIVE: The aim of this study was to assess patients' quality of life with different fusion levels in posterior pedicle screw correction of idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: No previous study has demonstrated differences in health-related quality of life (HRQoL) between patients fused to L3 versus L4. MATERIALS AND METHODS: A retrospective study was conducted on 30 scoliotic patients fused to L3 using complete pedicle screw instruments. Thirty age-matched and sex-matched scoliotic patients fused to L4 were in the control group. Radiologic parameters were assessed before surgery and at latest follow-up between the 2 groups. These 2 groups were compared for the Scoliosis Research Society 22 questionnaire (SRS-22), Oswestry Disability Index (ODI), visual analogue scale (VAS), and Short Form-36 (SF-36) questionnaires, which were administered preoperatively and at final follow-up. RESULTS: There were no significant differences in sex, age, follow-up duration, the distribution of curve patterns, the postoperative residual Cobb angle of the main curve, complications, or surgical method between the L3 and L4 groups (P>0.05). Preoperative scores were statistically similar in the L3 and L4 groups for all domains of all questionnaires. There was no difference between the L3 and L4 groups for ODI (P=0.527) and VAS (P=0.518). There were no significant differences in the scores on function/activity, self-image/appearance, pain, mental health, or satisfaction with treatment domains between the 2 groups. No significant differences between the 2 groups were found at the final follow-up in the SF-36 subscales/domain scores. CONCLUSIONS: This study attempted to elucidate the correlation between the length of fusion and functional outcome; however, it could not identify any difference between different fusion levels. On the basis of short-term results, there were no significant differences in the questionnaire scores between the 2 groups.

Congential scoliosis in Wilson's disease: case report and review of the literature.

BACKGROUND: Wilson's disease (WD) is an autosomal recessive disorder of copper metabolism, which leads to the accumulation of this metal in liver, brain, cornea and kidney. Little is reported about spinal deformity associated with this syndrome. This study is to present a case of thoracic kyphosis occurring in the setting of Wilson'disease and explore the possible association between the two diseases. CASE PRESENTATION: Case report and literature review. A previously unreported thoracic kyphosis in Wislon's disease is decribed. The patient was a 7-year-old Chinese female that underwent a posterior correction, using the Moss-SI spinal system performed at Thoracic 9-Lumbar 1 (T9-L1) levels. At 16-month follow-up, the patient was clinically pain free and well balanced. Plain radiographs showed solid spine fusion with no loss of deformity correction. After evaluating 211 WD patients referred to Peking Union Medical College Hospital from February 1991 to February 2012, the prevalence of congential scoliosis among patients with WD was 5.21% (11/211), much higher than that among general population (1/1000). CONCLUSIONS: To the best of our knowledge, this is the first report of WD with thoracic kyphosis. During sugery, surgeons and anesthesiologists must pay particular attention to the abnormal liver and brain function associated with WD. The prevalence of scoliosis is much higher among patients with WD, indicating a potential association between congential scoliosis and WD. However, the exact mechanism how copper-chelating agents induce scoliosis is unclear.

Leptin activates RhoA/ROCK pathway to induce cytoskeleton remodeling in nucleus pulposus cells.

Hyperleptinemia is implicated in obesity-associated lumbar disc degeneration. Nevertheless, the effect of leptin on the intracellular signaling of nucleus pulposus cells is not clear. The current study sought to delineate the possible involvement of the RhoA/ROCK pathway in leptin-mediated cytoskeleton reorganization in nucleus pulposus cells. Nucleus pulposus cells isolated from scoliosis patients were treated with 10 ng/mL of leptin. Fluorescent resonance energy transfer analysis was used to determine the activation of RhoA signaling in nucleus pulposus cells. The protein expression of LIMK1 and cofilin-2 were analyzed by western blot analysis. F-actin cytoskeletal reorganization was assessed by rhodamine-conjugated phalloidin immunoprecipitation. Leptin induced F-actin reorganization and stress fiber formation in nucleus pulposus cells, accompanied by localized RhoA activation and phosphorylation of LIMK1 and cofilin. The RhoA inhibitor C3 exoenzyme or the ROCK inhibitor Y-27632 potently attenuated the effects of leptin on F-actin reorganization and stress fiber formation. Both inhibitors also prevented leptin-induced phosphorylation of LIMK1 and cofilin-2. Our study demonstrated that leptin activated the RhoA/ROCK/LIMK/cofilin-2 cascade to induce cytoskeleton reorganization in nucleus pulposus cells. These findings may provide novel insights into the pathogenic mechanism of obesity-associated lumbar disc degeneration.

Comparison between subcutaneous closed-suction drainage and conventional closed-suction drainage in adolescent idiopathic scoliosis patients undergoing posterior instrumented spinal fusion: a randomized control trial.

STUDY DESIGN: Prospective, randomized controlled clinical study. OBJECTIVE: To evaluate the efficacy of subcutaneous closed-suction drainage in reducing blood loss as compared with conventional closed-suction drainage in adolescent idiopathic scoliosis cases undergoing posterior instrumented spinal fusion. BACKGROUND: Subcutaneous closed-suction drainage is reported to be a reasonable alternative to intra-articular indwelling closed-suction drainage and to that of no usage of any drainage system in knee arthroplasty. However, little is reported about the use of subcutaneous closed-suction drainage in adolescents idiopathic scoliosis patients undergoing posterior instrumented spinal fusion. METHODS: A total of 105 adolescent idiopathic scoliosis patients undergoing posterior instrumented spinal fusion were randomized into 2 groups of either a subcutaneous drainage or a conventional closed-wound suction drainage system. These 2 groups were compared for demographic distribution, blood loss (hemoglobin/hematocrit changes, transfusion requirements), and incidence of wound problems (requirements for dressing reinforcement, oozing, subcutaneous hematoma, ecchymosis, infection). RESULTS: Mean drainage volume was less (P=0.000) in the subcutaneous closed-wound suction drainage group compared with the conventional closed-wound suction drainage group (42 vs. 631 mL). The groups were statistically similar in terms of hemoglobin and hematocrit values obtained on the third postoperative day (10.60 vs. 9.52 g/dL, P=0.110; 30.85% vs. 27.82%, P=0.226), on discharge (10.90 vs. 9.75 g/dL, P=0.114; 31.10% vs. 28.13%, P=0.147), transfusion requirements (31.2% vs. 45.6%, P=0.133), and incidence of wound problems. However, the core temperature values were higher in subcutaneous closed-wound suction drainage group compared with the conventional closed-wound suction drainage group (P=0.001), and the duration of fever was longer in the former compared with the latter (P=0.008). CONCLUSIONS: The data suggest that subcutaneous closed-suction drainage offers a reasonable alternative to closed-wound suction drainage in adolescents idiopathic scoliosis patients undergoing posterior instrumented spinal fusion.

Nucleus Pulposus Cells from Calcified Discs Promote the Degradation of the Extracellular Matrix through Upregulation of the GATA3 Expression.

OBJECTIVE: Disc calcification is strongly associated with disc degeneration; however, the underlying mechanisms driving its pathogenesis are poorly understood. This study aimed to provide a gene expression profile of nucleus pulposus cells (NPCs) from calcified discs, and clarify the potential mechanism in disc degeneration. METHODS: Primary NPCs were isolated from calcified and control discs (CAL-NPC and CON-NPC), respectively. The proliferation and extracellular matrix (ECM) metabolism capacities of the cells were evaluated using MTT and Western blotting, respectively. RNA sequencing was used to identify differentially expressed genes (DEGs) in the CAL-NPCs. The biological functions of the DEGs were analyzed using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. The transcription factor database and Cytoscape software were used to construct the transcription factor-DEGs regulatory network. The role of the verified transcription factor in NPC proliferation and ECM metabolism was also investigated. RESULTS: The CAL-NPCs exhibited a lower proliferation rate and higher ECM degradation capacity than the CON-NPCs. In total, 375 DEGs were identified in the CAL-NPCs. The GO and KEGG analyses showed that the DEGs were primarily involved in the regulation of ribonuclease activity and NF-kappa B and p53 signaling pathways. GATA-binding protein 3 (GATA3) with the highest verified levels was selected for further studies. Overexpression of GATA3 in the CON-NPCs significantly inhibited their proliferation and promoted their ECM degradation function, while the knockdown of GATA3 in the CAL-NPCs resulted in the opposite phenotypes. CONCLUSION: This study provided a comprehensive gene expression profile of the NPCs from the calcified discs and supported that GATA3 could be a potential target for reversing calcification-associated disc degeneration.

Proteomic Comparison of Paraspinal Muscle Imbalance Between Idiopathic Scoliosis and Congenital Scoliosis.

OBJECTIVE: This study aims to compare the proteomic profiles of paraspinal muscle imbalance between idiopathic scoliosis (IS) and congenital scoliosis (CS). METHODS: Bilateral paraspinal muscles of 5 pairs of matched IS and CS patients were collected. Proteome patterns of paraspinal muscles were established. Differentially expressed proteins (DEPs) in paraspinal muscles between the convexity and the concavity were screened out. DEPs shared by both IS and CS and IS-specific DEPs were identified. Bioinformatic analyses of DEPs were performed. RESULTS: Among 105 DEPs identified in IS, 30 displayed predominant expression on the convexity, whereas other 75 exhibited predominant expression on the concavity. DEPs in IS were mainly enriched in calcium ion binding and DNA binding in gene ontology (GO) term and glycolysis/gluconeogenesis and purine metabolism in Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. Among 48 DEPs identified in CS, 25 were predominantly expressed on the convexity and 23 on the concavity. DEPs in CS were mainly enriched in receptor activity and immune response in GO term and glycolysis/gluconeogenesis and cellular senescence in KEGG pathway. Comparison of DEPs between IS and CS identified only 8 proteins shared by both types of scoliosis. Among the 97 IS-specific DEPs, 28 were predominantly expressed on the convexity and 69 on the concavity. IS-specific genes were enriched in calcium ion binding and protein glycosylation in GO term and glycolysis/gluconeogenesis and hypertrophic cardiomyopathy in KEGG pathway. CONCLUSION: IS and CS exhibit proteomic imbalance in bilateral paraspinal muscles but share few similarities. Paraspinal muscle imbalance in IS might not be the consequence of spinal deformities.

Unilateral interlaminar fenestration on the convex side provides a reliable access for intrathecal administration of nusinersen in spinal muscular atrophy: a retrospective study.

BACKGROUND: As the first gene therapy for spinal muscular atrophy (SMA), nusinersen is supposed to be administrated via intrathecal injection regularly for a lifetime. However, for SMA patients with severe spinal deformities, bony fusion following posterior spinal instrumentation sets great obstacles for the application of nusinersen. Therefore, efforts have been devoted to the exploration of appropriate approach for nusinersen administration. This study aims to evaluate the safety and reliability of unilateral interlaminar fenestration on the convex side during spinal fusion surgery for intrathecal nusinersen injection in SMA. RESULTS: SMA patients receiving posterior spinal fusion and interlaminar fenestration in Peking Union Medical College Hospital from January 2020 to October 2021 were retrospectively analyzed. 13 patients were included. Of the 13 patients, 10 were classified into SMA type II and 3 into SMA type III. Distal fusion to pelvis was undertaken in 11 patients; while L5 was selected as the lowest instrumented vertebra in the other 2 patients. All patients received interlaminar fenestration on the convex side only with an area of about 15 mm × 20 mm. Fenestration at L2-L3 level was performed in 6 patients; while L3-L4 level was selected for windowing in the remaining 7 patients. 9 of the 13 patients received lumbar puncture and intrathecal nusinersen administration during the 1-year follow-up, with an accumulative total of 50 times. All injections were performed successfully under ultrasound guidance, with no one transferred to radiographic assistance. No severe complications occurred after injection. CONCLUSIONS: In SMA with severe scoliosis planning to receive posterior spinal fusion, unilateral lumbar interlaminar fenestration on the convex side provides a feasible and reliable access for intrathecal nusinersen administration after surgery.

Kaposiform hemangioendothelioma with adolescent thoracic scoliosis: a case report and review of literature.

Kaposiform hemangioendothelioma (KHE) is a rare locally aggressive vascular tumor that usually presents as a superficial or deep soft tissue mass with associated cutaneous lesions. We report a unique spinal KHE with painless thoracic scoliosis in a 14-year-old girl. She underwent simultaneous tumor biopsy, spinal deformity correction and fusion. At 3 years follow-up, the patient's MRI showed no significant deterioration of process without any therapy. KHE presenting as scoliosis is rare and to our knowledge this is the first recognized case in the reported world literature.

[Experimental study of three dimensional navigation assisted spinal surgery by multi-segment registration technology based on structured light scanning].

OBJECTIVE: To study the registration method based on structured light scanning for navigation assisted spinal surgery and assess its accuracy so as to construct a registration system for the navigation assisted spinal surgery using structured light scanning. METHODS: Both the computed tomographic (CT) dataset and the structured light scanning images of thoracic vertebra were obtained. The pre-registration and multi-segment iterative closest point (ICP) algorithm were used for the registration of CT images and structured light images. Four segmentations were selected from the surface of thoracic vertebra and placed into different combinations. The accuracy for each combination was studied. Noise and perturbation were exerted to structured light and registration accuracy was studied. And calf vertebra was used for further verification. RESULTS: A combination of pre-registration and multi-segment iterative closest point (ICP) algorithm was competent for the registration of CT scanning data and the structured light scanning data. The registration error was less than 1 mm when two and more segments were selected for registration combination. The registration error was less than 1 mm when noise was exerted. CONCLUSION: With a high accuracy and a perturbation resistance, a combination of pre-registration and multi-segment registration algorithm based on structured light scanning is competent for the registration of CT scanning data and structured light scanning data.

Phosphoglycerate kinase 1 silencing by a novel microRNA microRNA-4523 protects human osteoblasts from dexamethasone through activation of Nrf2 signaling cascade.

Nuclear-factor-E2-related factor 2 (Nrf2) cascade activation can ameliorate dexamethasone (DEX)-induced oxidative injury and death in human osteoblasts. Phosphoglycerate kinase 1 (PGK1) depletion is shown to efficiently activate Nrf2 signaling by inducing methylglyoxal modification of Kelch-like ECH-associated protein 1 (Keap1). We here identified a novel PGK1-targeting microRNA: microRNA-4523 (miR-4523). RNA fluorescent in situ hybridization, RNA pull-down, and Argonaute-2 RNA immunoprecipitation results confirmed a direct binding between miR-4523 and PGK1 mRNA in primary human osteoblasts and hFOB1.19 osteoblastic cells. Forced overexpression of miR-4523, using a lentiviral construct, robustly decreased PGK1 3'-UTR (untranslated region) luciferase activity and downregulated its expression in human osteoblasts and hFOB1.19 cells. Furthermore, miR-4523 overexpression activated the Nrf2 signaling cascade, causing Keap1-Nrf2 disassociation, Nrf2 protein stabilization, and its nuclear translocation as well as transcription activation of Nrf2-dependent genes (NQO1, GCLC, and HO1) in human osteoblasts. By expressing a UTR-null PGK1 construct, miR-4523 overexpression-induced Nrf2 cascade activation was however largely inhibited. Importantly, DEX-induced reactive oxygen species production, oxidative injury, and cell apoptosis were significantly attenuated by miR-4523 overexpression in human osteoblasts and hFOB1.19 cells. Such actions by miR-4523 were abolished by Nrf2 shRNA or knockout, but mimicked by PGK1 knockout (using CRISPR/Cas9 method). In PGK1 knockout human osteoblasts, miR-4523 overexpression failed to further increase Nrf2 cascade activation and offer osteoblast cytoprotection against DEX. Significantly, miR-4523 is downregulated in human necrotic femoral head tissues of DEX-taking patients. Together, PGK1 silencing by miR-4523 protected human osteoblasts from DEX through activation of the Nrf2 signaling cascade.

DCAF1-targeting microRNA-3175 activates Nrf2 signaling and inhibits dexamethasone-induced oxidative injury in human osteoblasts.

Activation of nuclear-factor-E2-related factor 2 (Nrf2) signaling can protect human osteoblasts from dexamethasone-induced oxidative injury. DDB1 and CUL4 associated factor 1 (DCAF1) is a novel ubiquitin E3 ligase for Nrf2 protein degradation. We identified a novel DCAF1-targeting miRNA, miR-3175. RNA pull-down, Argonaute 2 RNA-immunoprecipitation, and RNA fluorescent in situ hybridization results confirmed a direct binding between miR-3175 and DCAF1 mRNA in primary human osteoblasts. DCAF1 3'-untranslated region luciferase activity and its expression were significantly decreased after miR-3175 overexpression but were augmented with miR-3175 inhibition in human osteoblasts and hFOB1.19 osteoblastic cells. miR-3175 overexpression activated Nrf2 signaling, causing Nrf2 protein stabilization, antioxidant response (ARE) activity increase, and transcription activation of Nrf2-dependent genes in human osteoblasts and hFOB1.19 cells. Furthermore, dexamethasone-induced oxidative injury and apoptosis were largely attenuated by miR-3175 overexpression in human osteoblasts and hFOB1.19 cells. Importantly, shRNA-induced silencing or CRISPR/Cas9-mediated Nrf2 knockout abolished miR-3175 overexpression-induced osteoblast cytoprotection against dexamethasone. Conversely, DFAC1 knockout, by the CRISPR/Cas9 method, activated the Nrf2 cascade and inhibited dexamethasone-induced cytotoxicity in hFOB1.19 cells. Importantly, miR-3175 expression was decreased in necrotic femoral head tissues of dexamethasone-taking patients, where DCAF1 mRNA was upregulated. Together, silencing DCAF1 by miR-3175 activated Nrf2 signaling to inhibit dexamethasone-induced oxidative injury and apoptosis in human osteoblasts.

Predictive factors of postoperative pulmonary complications in scoliotic patients with moderate or severe pulmonary dysfunction.

STUDY DESIGN: Retrospective clinical study. OBJECTIVE: To evaluate the predictive factors of postoperative pulmonary complications in unselected scoliotic patients with moderate or severe pulmonary dysfunction. BACKGROUND: Many scoliotic patients with moderate or severe pulmonary dysfunction develop postoperative pulmonary complications during hospitalization. However, little is reported about the postoperative pulmonary complication events in this population at the first visit to the hospital. METHODS: A total of 88 scoliotic patients with moderate or severe pulmonary dysfunction were identified. The demographic distribution, medical history, and clinical data were collected to investigate the predictive factors of immediate postoperative pulmonary complications by logistic regression. RESULTS: A total of 16 (18.2%) patients were documented with postoperative pulmonary complications including increased requirement of postoperative ventilatory support (6.3%), atelectasis (31.3%), pneumothorax (6.3%), pneumonia (12.5%), and hypoxemia (43.8%). There were no statistical differences in age, sex, body mass index, abnormal echocardiogram, and prior symptoms between the 2 groups (P>0.05). Of the patients with postoperative pulmonary complications, a slightly higher proportion of patients underwent anterior approach, 2 (12.5%) versus 2 (2.8%) (P=0.091). The Cobb angle before surgery was 102.1+/-25.5 degree with postoperative pulmonary complications versus 87.7+/-23.8 degree without postoperative pulmonary complications (P=0.034). Forced vital capacity was 47.0+/-10.5% versus 52.4+/-9.0% (P=0.037). Number of levels fused was 13.7+/-2.3 versus 13.1+/-2.2 (P=0.319). Operation time was 376.8+/-125.6 minutes versus 350.4+/-97.8 minutes (P=0.357). Anesthesia time was 415.3+/-126.8 minutes versus 388.0+/-97.5 minutes (P=0.341). Estimated blood loss was 1050.0+/-769.4 mL versus 777.8+/-460.9 mL (P=0.065), respectively. Logistic regression analysis showed that thoracoplasty correlated with postoperative pulmonary complications (odds ratio 3.81, 95% confidence interval 1.11-13.16). CONCLUSIONS: Thoracoplasty is the only independent predictor of postoperative pulmonary complications. However, the abnormal echocardiogram, prior symptoms, forced vital capacity, and other clinical characteristics play a less relevant role in the prediction of postoperative pulmonary complications.

[Differential expressed proteins of knee osteoarthritic chondrocytes].

OBJECTIVE: To investigate the molecular mechanism of osteoarthritis (OA) through the differential expressed proteins of advanced osteoarthritic chondrocytes. METHODS: Normal articular cartilage (NAC, n = 22) were obtained from knee cartilage of donors without knee diseases and osteoarthritic cartilage (OAC, n = 17) from OA patients undergoing knee arthroplasty. Total protein was extracted from chondrocytes and loaded directly for two-dimensional gel electrophoresis (2-DE). Gel images were analyzed with the software Imagemaster 2-D platinum3.0 to screen the differential expression protein spots. Target spots were excised and digested and the resulting peptides submitted for mass spectrometry analysis. Identities of differential expressed proteins were recognized through matching the peptide mass finger printing of each spot with NCBI protein database by MASCOT. RESULTS: About 1000 protein spots were presented in the 2-DE gels for each group. Thirty-five NAC spots and 31 OAC spots were confirmed to be differential expression protein spots. Among these spots, 19 proteins were identified by MASCOT, including type VI collagen, enzymes involved in collagen synthesis, shock related proteins and some novel proteins with unknown functions. CONCLUSION: The differential expressed proteins isolated and identified by the present study provide valuable information on various aspects of OA pathology. It may help us to gain new insights into the molecular mechanism of OA.

[Selection of distal fusion levels in the surgical management of thoracolumbar/lumbar adolescent idiopathic scoliosis].

OBJECTIVE: To investigate the efficacy and safety of a new method which determines the exact distal fusion level in the treatment of adolescent idiopathic scoliosis (AIS) with posterior pedicle screw fixation and to assess its clinical outcome. METHODS: This prospective clinical study analyzed 31 AIS patients who met the inclusion criteria enrolled from July 2005 to September 2008. Based on the principle of our new criteria for selection of distal fusion level of AIS, all patients had posterior spinal fusion and instrumentation with pedicle screws. Cobb angle of the curve, tilt angle of the LIV, intervertebral angle and trunk shift were measured and analyzed. RESULTS: Preoperative (42 + or - 17) degrees of thoracic curve was corrected to (12 + or - 7) degrees , with a curve correction of 70.6%. Preoperative (44 + or - 7) degrees of lumbar curve was corrected to (9 + or - 4) degrees , with a curve correction of 80.2%. The trunk shift were significantly improved from (13 + or - 8) mm to (9 + or - 7) mm before and after surgery respectively (P < 0.05). The tilt angles of the LIV before and after surgery were (20.8 + or - 5.7) degrees and (1.5 + or - 3.1) degrees respectively. The thoracic Cobb angle was (14 + or - 8) degrees and the lumbar Cobb angle was (9 + or - 5) degrees at latest follow up. The changes were of significance in the tilt angle of the LIV after surgery compared with that before surgery (P = 0.000). This angle averaged (0.8 + or - 3.7) degrees at final follow up, but the change was not significant compared with that after surgery (P > 0.05). CONCLUSION: This is an effective method with the advantage of shortening the fusion level, reserving the distal motion segments and easing segmental degeneration adjacent to the fusion area.