Paxillin Is Required for Proper Spinal Motor Axon Growth into the Limb.

To assemble the functional circuits of the nervous system, the neuronal axonal growth cones must be precisely guided to their proper targets, which can be achieved through cell-surface guidance receptor activation by ligand binding in the periphery. We investigated the function of paxillin, a focal adhesion protein, as an essential growth cone guidance intermediary in the context of spinal lateral motor column (LMC) motor axon trajectory selection in the limb mesenchyme. Using in situ mRNA detection, we first show paxillin expression in LMC neurons of chick and mouse embryos at the time of spinal motor axon extension into the limb. Paxillin loss-of-function and gain-of-function using in ovo electroporation in chick LMC neurons, of either sex, perturbed LMC axon trajectory selection, demonstrating an essential role of paxillin in motor axon guidance. In addition, a neuron-specific paxillin deletion in mice led to LMC axon trajectory selection errors. We also show that knocking down paxillin attenuates the growth preference of LMC neurites against ephrins in vitro, and erythropoietin-producing human hepatocellular (Eph)-mediated retargeting of LMC axons in vivo, suggesting paxillin involvement in Eph-mediated LMC motor axon guidance. Finally, both paxillin knockdown and ectopic expression of a nonphosphorylable paxillin mutant attenuated the retargeting of LMC axons caused by Src overexpression, implicating paxillin as a Src target in Eph signal relay in this context. In summary, our findings demonstrate that paxillin is required for motor axon guidance and suggest its essential role in the ephrin-Eph signaling pathway resulting in motor axon trajectory selection.SIGNIFICANCE STATEMENT During the development of neural circuits, precise connections need to be established among neurons or between neurons and their muscle targets. A protein family found in neurons, Eph, is essential at different stages of neural circuit formation, including nerve outgrowth and pathfinding, and is proposed to mediate the onset and progression of several neurodegenerative diseases, such as Alzheimer's disease. To investigate how Ephs relay their signals to mediate nerve growth, we investigated the function of a molecule called paxillin and found it important for the development of spinal nerve growth toward their muscle targets, suggesting its role as an effector of Eph signals. Our work could thus provide new information on how neuromuscular connectivity is properly established during embryonic development.

Effects of a comprehensive physical therapy on moderate and severe obstructive sleep apnea- a preliminary randomized controlled trial.

BACKGROUND: Critically compromised by upper airway anatomical impaired properties, obstructive sleep apnea (OSA) can be categorized into different phenotypic traits, mainly including oropharyngeal muscle dysfunction. The upper airway muscle strength training was targeted on oropharyngeal muscle dysfunction by re-educating the oropharyngeal muscles to maintain the upper airway patency. OSA was characterized with multilevel collapsibility of the upper airway; however, the programs are still inconsistent and the effects are unknown. Therefore, the purpose of this study was to investigate the effects of a comprehensive physical therapy on OSA. METHODS: Fifteen subjects with newly diagnosed moderate or severe OSA (AHI ≥ 15) were randomized into intervention and control groups. The intervention group underwent a 12-week-intervention of hospital based physical therapy, while the control group was kept on waiting for 12 weeks. Polysomnography (PSG) data, oropharyngeal and respiratory muscle performance were measured before and after intervention. RESULTS: In intervention group (n = 8), AHI was significantly improved (from 46.96 ± 19.45 to 32.78 ± 10.78 events/h, p = 0.017); in control group (n = 7), AHI was significantly increased (from 35.77 ± 17.49 to 42.96 ± 17.32 events/h, p = 0.043). While the control group remained no change between pre- and post- intervention, the intervention group demonstrated that other PSG outcomes significantly improved, including arousal index (46.04 ± 18.9 versus 32.98 ± 8.35/h), mean SpO2 (92.88 ± 2.1 versus 94.13 ± 1.46%), and oxygen desaturation index (ODI) (31.13 ± 19.48 versus 20.57 ± 7.83/h). CONCLUSION: This comprehensive physical therapy can be prescribed for the significant clinical improvement on sleep apnea for the patients with moderate and severe OSA.

Ephexin1 Is Required for Eph-Mediated Limb Trajectory of Spinal Motor Axons.

The precise assembly of a functional nervous system relies on the guided migration of axonal growth cones, which is made possible by signals transmitted to the cytoskeleton by cell surface-expressed guidance receptors. We investigated the function of ephexin1, a Rho guanine nucleotide exchange factor, as an essential growth-cone guidance intermediary in the context of spinal lateral motor column (LMC) motor axon trajectory selection in the limb mesenchyme. Using in situ mRNA detection, we first show that ephexin1 is expressed in LMC neurons of chick and mouse embryos at the time of spinal motor axon extension into the limb. Ephexin1 loss of function and gain of function using in ovo electroporation in chick LMC neurons, of either sex, perturbed LMC axon trajectory selection, demonstrating an essential role of ephexin1 in motor axon guidance. In addition, ephexin1 loss in mice of either sex led to LMC axon trajectory selection errors. We also show that ephexin1 knockdown attenuates the growth preference of LMC neurites against ephrins in vitro and Eph receptor-mediated retargeting of LMC axons in vivo, suggesting that ephexin1 is required in Eph-mediated LMC motor axon guidance. Finally, both ephexin1 knockdown and ectopic expression of nonphosphorylatable ephexin1 mutant attenuated the retargeting of LMC axons caused by Src overexpression, implicating ephexin1 as an Src target in Eph signal relay in this context. In summary, our findings demonstrate that ephexin1 is essential for motor axon guidance and suggest an important role in relaying ephrin:Eph signals that mediate motor axon trajectory selection.SIGNIFICANCE STATEMENT The proper development of functioning neural circuits requires precise nerve connections among neurons or between neurons and their muscle targets. The Eph tyrosine kinase receptors expressed in neurons are important in many contexts during neural-circuit formation, such as axon outgrowth, axon guidance, and synaptic formation, and have been suggested to be involved in neurodegenerative disorders, including amyotrophic lateral sclerosis and Alzheimer's disease. To dissect the mechanism of Eph signal relay, we studied ephexin1 gain of function and loss of function and found ephexin1 essential for the development of limb nerves toward their muscle targets, concluding that it functions as an intermediary to relay Eph signaling in this context. Our work could thus shed new light on the molecular mechanisms controlling neuromuscular connectivity during embryonic development.

Drainage outflow restriction as a parameter associated with cortical venous reflux in craniofacial arteriovenous malformations with cavernous sinus drainage.

PURPOSE: Craniofacial arteriovenous malformations (CF-AVMs) are locally aggressive extracranial lesions. When CF-AVMs involve cavernous sinus (CS) as their draining vein, they represent a special subgroup which may interfere intracranial venous system. In this study, we aimed to analyze the venous drainage patterns of CF-AVMs with CS drainage and to demonstrate how it affected our treatment strategy. METHODS: Cases of CF-AVMs associated with CS drainage were collected from a prospectively collected database of patients with CF-AVMs who underwent endovascular treatment from September 2016 to March 2018. Clinical data and angioarchitectural findings were analyzed. Factors associated with the presence of venous reflux (cortical venous reflux (CVR) or dural sinus reflux (DSR)) were analyzed. RESULTS: Fifteen CF-AVM patients associated with CS drainage were analyzed. Three cases of venous reflux from the CS were identified (CVR, 2; DSR, 1). Lesions with unilateral venous drainage, ≤ 2 draining veins, and the absence of antegrade CS outflow were more likely to develop venous reflux from the CS. We successfully performed additional trans-venous coil embolization of the superior ophthalmic vein in two patients with malformations associated with venous reflux to close this venous connection to the CS. CONCLUSION: CF-AVMs associated with CS drainage confer an increased risk of CVR and DSR, especially in cases where the drainage outflow is restricted. Identification of this venous angioarchitecture is essential in the evaluation and treatment planning of CF-AVMs.

Disability, emotional distress and well-being among patients with lumbar spondylolisthesis.

AIM AND OBJECTIVE: To explore the disability, emotional distress and well-being of patients with lumbar spondylolisthesis. BACKGROUND: Few studies have investigated the correlations between disability, emotional distress and well-being of patients with lumbar spondylolisthesis. DESIGN: This study used a cross-sectional research design. METHODS: Participants were 133 patients aged over 50 years who were experiencing lumbar spondylolisthesis. The research instruments included a demographic information questionnaire; the Numeric Rating Scale (NRS); the Charlson Comorbidity Index (CCI); the Chinese versions of the Oswestry Disability Index (ODI), State-Trait Anxiety Inventory-State (STAI-S) and Center for Epidemiological Study-Depression (CES-D); and the Psychological Well-being (PWB) Scale. Emotional distress was measured by the STAI-S and CES-D. Pearson's correlations coefficient, multiple linear regression and a mediating effect model were introduced to explore correlations between the variables and predictors of psychological well-being, and details of the methods are reported in coherence to STROBE criteria. RESULTS: Eighty-six participants (64.6%) had moderate and severe anxiety, and 42 (31.6%) experienced depression. Participants reported medium to high levels of well-being; "satisfaction with interpersonal relationships" was rated the highest and "physical and mental health" the lowest. Disability, depression and anxiety had significant negative correlations with well-being. Depression and anxiety mediated the relationship between disability and well-being. Moreover, depression, family support, educational background and anxiety were predictors of well-being, accounting for 39.1% of the total variance. CONCLUSIONS: Disability and emotional distress among patients with lumbar spondylolisthesis had a negative impact on well-being. Anxiety and depression were closely correlated with and substantially influenced well-being. RELEVANCE TO CLINICAL PRACTICE: Health professionals will enhance the understanding of important factors influencing well-being among patients with lumbar spondylolisthesis. This study suggests the conduct of depression and anxiety evaluations at outpatient clinics and prior to surgery, so that clinicians will be aware of the emotional distress status of patients with lumbar spondylolisthesis and, therefore, enhance their well-being.

Nck2 is essential for limb trajectory selection by spinal motor axons.

BACKGROUND: The development of a functioning nervous system requires precise assembly of neuronal connections, which can be achieved by the guidance of axonal growth cones to their proper targets. How axons are guided by signals transmitted to the cytoskeleton through cell surface-expressed guidance receptors remains unclear. We investigated the function of Nck2 adaptor protein as an essential guidance intermediary in the context of spinal lateral motor column (LMC) motor axon trajectory into the limb. RESULTS: Nck2 mRNA and protein are preferentially expressed in the medial subgroups of chick LMC neurons during axon trajectory into the limb. Nck2 loss- and gain-of-function in LMC neurons using in ovo electroporation perturb LMC axon trajectory selection demonstrating an essential role of Nck2 in motor axon guidance. We also showed that Nck2 knockdown and overexpression perturb the growth preference of LMC neurites against ephrins in vitro and Eph-mediated redirection of LMC axons in vivo. Finally, the significant changes of LMC neurite growth preference against ephrins in the context of Nck2 and α2-chimaerin loss- and gain-of-function implicated Nck2 function to modulate α2-chimaerin activity. CONCLUSIONS: Here, we showed that Nck2 is required for Eph-mediated axon trajectory selection from spinal motor neurons through possible interaction with α2-chimaerin. Developmental Dynamics 247:1043-1056, 2018. © 2018 Wiley Periodicals, Inc.

Brain abscess caused by Citrobacter koseri infection in an adult.

Citrobacter koseri is a gram-negative bacillus that causes mostly meningitis and brain abscesses in neonates and infants. However, brain abscess caused by Citrobacter koseri infection in an adult is extremely rare, and only 2 cases have been described. Here, we reported a 73-year-old male presenting with a 3-week headache. A history of diabetes mellitus was noted. The images revealed a brain abscess in the left frontal lobe and pus culture confirmed the growth of Citrobacter koseri. The clinical symptoms improved completely postoperatively.

Contralateral acute subdural hematoma occurring after evacuation of subdural hematoma with coexistent contralateral subdural hygroma.

Burr-hole craniostomy with closed-system drainage is a safe and effective method for the management of chronic subdural hematoma. However, contralateral acute subdural hematoma has been reported to be a rare and devastating complication. Only 3 cases have been described in the literature. Herein, we reported an 80-year-old male with chronic subdural hematoma and contralateral subdural hygroma. The burr-hole craniostomy with closed-system drainage was initially performed to treat the chronic subdural hematoma. Three days after surgery, weakness of the extremities developed, and contralateral acute subdural bleeding within the previous subdural hygroma was diagnosed by CT scan of the brain. The pathophysiological mechanism of this rare complication was discussed, and the relevant literature was also reviewed.

Trans-Pars Interarticularis Approach for Lumbar Interbody Fusion: An Efficient, Straightforward, and Minimally Invasive Surgery for Lumbar Spondylolisthesis and Stenosis.

PURPOSE: Lumbar interbody fusion is a commonly applied surgical treatment for spondylolisthesis. For this procedure, various minimally invasive approaches have been developed, including posterior lumbar interbody fusion, transforaminal lumbar interbody fusion (TLIF), oblique lumbar interbody fusion, and anterior lumbar interbody fusion. OBJECTIVE: In this study, we characterized the features of a minimally invasive (MIS) trans-pars interarticularis approach for lumbar interbody fusion (TPLIF) and compared its surgical outcomes with those of MIS-TLIF. METHODS: This study included 89 and 44 patients who had undergone MIS-TPLIF and MIS-TLIF, respectively, between September 2016 and December 2022. The following clinical outcomes were analyzed: operative time, blood loss, and hospitalization duration. RESULTS: For the MIS-TPLIF and MIS-TLIF groups, the average operative time, blood loss, and hospitalization duration were, respectively 98.28 and 191.15 min, 41.97 and 101.85 mL, and 5.8 and 6.9 days. CONCLUSION: The MIS-TPLIF approach for lumbar spondylolisthesis or other degenerative diseases involves the use of the commonly available and cost-effective instrument Taylor retractor, thus enabling posterior lumbar interbody fusion to be performed with minimal invasion. This approach also confers the benefits of a short learning curve and an intuitive approach. Our results suggest that although MIS-TPLIF is noninferior to MIS-TLIF, it is easier to learn and perform than MIS-TLIF.

Risk factors for bone cement dislodgement following balloon kyphoplasty for osteoporotic vertebral compression fracture.

OBJECTIVE: The study aimed to determine the incidence and risk factors associated with bone cement dislodgement in patients with osteoporotic vertebral compression fracture following balloon kyphoplasty treatment. METHODS: A retrospective study was conducted on 203 patients who underwent kyphoplasty in 255 vertebral bodies between January 2017 and December 2021. The patients were categorized into two groups: the bone cement dislodgment group (n = 16) and the non-bone cement dislodgement group (n = 239). Various patient characteristics and radiologic parameters were evaluated. Statistical analysis involved the assessment of the background homogeneity of the group by using independent sample t tests, chi-square tests, and Fisher's exact. Univariate and multivariate logistic regression analyses were performed to explore the impact of background variables on cement dislodgement. RESULTS: The results revealed that split-type fracture (χ2 = 31.706, p < 0.001), DISH (χ2 = 18.827, p = 0.011), pedicle fracture (χ2 = 22.246, p < 0.001), endplate deficit (χ2 = 14.023, p < 0.001), posterior wall injury (χ2 = 29.124, p < 0.001), and intervertebral vacuum cleft (χ2 = 21.469, p < 0.001) were the factors that significantly differed between the two groups. The multivariate logistic regression analysis revealed posterior wall injury (OR = 12.983, p = 0.025) and intervertebral vacuum cleft (OR = 5.062, p = 0.024) to be independent risk factors. CONCLUSION: The incidence of bone cement dislodgement in our study was 6.3%. This study underscores the importance of using preoperative radiologic parameters to predict the risk of bone cement dislodgement following balloon kyphoplasty.

A Three-Dimensional Morphological Assessment for Evaluating Pre- and Postsurgery in Cervical Laminoplasty.

OBJECTIVE: The efficacy of medical treatments and the changes in radiologic imaging before and after treatment have consistently remained pivotal factors. This is particularly critical for surgical procedures, where precise evaluation of disparities pre and postsurgery or the accuracy of implantation is paramount. Based on three-dimensional morphological interests, we provide an automatic quantification evaluation method that delivers an evident base for assessing the outcomes of a widely employed surgical technique, cervical laminoplasty. METHODS: The sample study included patients who underwent cervical laminoplasty for cervical spondylotic myelopathy/ossification of the longitudinal ligament. We present a superimposition method that facilitates a unique and precise assessment between pre and postsurgery. The degree of expansion was evaluated by the canal volume increase and canal expansion rate after surgery. RESULTS: There were 31 patients with 112 vertebral segments measured. The target cervical's pre and postoperative canal areas were 122.63 ± 30.34 and 196.50 ± 37.10 mm2, respectively (P < 0.001). The average cervical canal expansion rate was 64.42%. The expansion effect of C5 cervical laminoplasty was the maximum (71.01%), and the canal volume of other segments expanded by approximately 60%. The functional outcomes demonstrated significant improvements in symptoms. CONCLUSIONS: The quantification evaluation method can be utilized for any morphology changes before and after laminoplasty, as it does not lead to errors or variations from different inspection machines or human factors. The automatic method delivers an evident base for assessing the outcomes of a widely employed surgical technique.

Combining Laminoplasty With Artificial Disc Replacement for the Treatment of Cervical Spondylotic Myelopathy With Congenital Cervical Stenosis.

BACKGROUND: Cervical spondylotic myelopathy (CSM) is a very common and devastating spinal disease. Congenital cervical stenosis (CCS) is the most common cause. We aimed to elucidate the security, effectivity, and feasibility of surgery combining laminoplasty with artificial disc replacement (ADR) to treat CSM patients with radiculopathy, especially for preserving the range of motion (ROM) of the cervical spine. METHOD: Between August 2008 and April 2019, 39 patients with multiple CSM caused by CCS were enrolled in the present study. All patients received laminoplasty first and then ADR. We used a retrospective collection of data for evaluating the functional and radiologic outcomes, especially regarding preservation of ROM. RESULTS: Each patient underwent at least a 2-year postoperative follow-up. The Japanese Orthopedic Association score showed great improvements at 6 months. The ADR index-level ROM was preserved during follow-up. The subaxial Cobb angle could also be retained in the whole cervical spine, and the spinal canal diameter could be expanded by more than 52.6%. There were no severe complications or side effects, and no patients needed secondary surgery. CONCLUSIONS: We aimed to treat multiple levels of CSM with adequate decompression without too many intervertebral disc replacements. We were able to expand the spinal canal directly for these patients with CCS and needed only 1- or 2-level ADR to treat them with associated radiculopathy. This combined surgical strategy was secure, effective, and was able to preserve the ROM of the cervical spine.

Two-dimensional C-arm robotic navigation system (i-Navi) in spine surgery: a pilot study.

PURPOSE: Pedicle screws placement is very common procedure in spinal surgery. Robotic assisted surgery has been widely used in this operation. We assessed the accuracy of thoracolumbar spine trans-pedicle screws (TPS) implantation utilizing a noval robotic navigation system (i-Navi robotic navigation system) by planning with two-dimensional (2-D) C-arm. METHODS: This study was approved by the Institutional Review Board of the Cathay General Hospital on June 21, 2018 (IRB number: CGH-P 106,092), and written informed consents were obtained from all the patients. There are 18 patients were enrolled in the study. All the patients received the posterior fusion with TPS insertion under the assistant of our robotic navigation system. RESULTS: There are 18 patients were included into our study, there are 2 patients were quitted from the study due to the equipment setup was not complete. Other 16 patients completed the entire procedure successfully. There is total 88 pedicle screws were inserted through i-Navi robotic navigation system. There are 79 of 88 screws were graded A, and 9 screws were graded B; no screws were graded C or D. No vascular or nerve injuries were noted after the operations. CONCLUSION: We present our i-Navi robotic navigation system, by planning with 2-D C-arm imaging and pre-operative CT scans. According to the results of study, we think it can provide a reliable and easy tool to perform the TPS in thoracic lumbar spine surgery.

Hydrostatic pressure facilitates calcium deposition and osteogenic gene expression in the osteoblastic differentiation of placenta-derived multipotent cells.

OBJECTIVE: We tested the osteoblastic differentiation effects caused by physical stimulation such as hydrostatic pressure using placenta-derived multipotent cells. MATERIALS AND METHODS: The placenta-derived multipotent cells (PDMCs) were treated with osteogenic medium to induce PDMCs differentiation into osteoblast-like cells. The induced PDMCs were stimulated using hydrostatic pressure at a magnitude of 30 kPa for 1 h/day for up to 12 days. The calcium deposition monitored by Alizarin Red staining and the calcium content of each experimental group were quantified. RESULTS: The results demonstrated both the calcium deposition and concentration were elevated through hydrostatic pressure stimulation. Moreover, in order to indicate of PDMC osteodifferentiation, RT-qPCR analysis were performed and mRNA expression of osteoblast differentiation markers (type I collagen, alkaline phosphatase, RUNX2, and BGLAP), the bone morphogenetic protein family (BMP1-7) and BMP receptors (BMPR1A, BMPR1B, and BMPR2) were examined. Among them, the mRNA levels of RUNX2, COL1A1, BMP1, BMP3, and BMPR1A increased significantly in the hydrostatic-pressure-stimulated groups, whereas BGLAP, ALP, BMP2, BMP6, BMPR1B, and BMPR2 exhibited a slight upregulation between the control and experimental groups, indicating the specific signal route induced by hydrostatic pressure on PDMCs. CONCLUSION: Our results revealed the beneficial effects of stem cells stimulated using hydrostatic pressure, which could enhance calcium deposition considerably and facilitate osteodifferentiation, and the results may be applied to tissue regeneration in the near future.

Paraplegia after Hypotension with Pneumothorax Episode during Thoracic Spine Tumor Surgery.

Paraplegia after spine surgery is a catastrophic complication. Here, we present a patient who, following laminectomy and fusion for decompression of metastatic tumor, developed paraplegia. We tried to find out the possible reason for the paraplegia. Due to prolonged hypotension during operation and new onset of pneumothorax, we think that intraoperative prolonged hypotension leads to the spinal cord ischemia which may cause neurological deterioration of paraplegia. Maintaining hemodynamic stability during spinal surgery is very important.

Shugosin 2 is a biomarker for pathological grading and survival prediction in patients with gliomas.

Glioblastomas are the most common type of adult primary brain neoplasms. Clinically, it is helpful to identify biomarkers to predict the survival of patients with gliomas due to its poor outcome. Shugoshin 2 (SGO2) is critical in cell division and cell cycle progression in eukaryotes. However, the association of SGO2 with pathological grading and survival in patients with gliomas remains unclear. We analyzed the association between SGO2 expression and clinical outcomes from Gene Expression Omnibus (GEO) dataset profiles, The Cancer Genome Atlas (TCGA), and Chinese Glioma Genome Atlas (CGGA). SGO2 mRNA and protein expression in normal brain tissue and glioma cell lines were investigated via quantitative RT-PCR, Western blot, and IHC staining. The roles of SGO2 in proliferation, migration, and apoptosis of GBM cells were studied with wound-healing assay, BrdU assay, cell cycle analysis, and JC-1 assay. The protein-protein interaction (PPI) was analyzed via Search Tool for the Retrieval of Interacting Genes/Proteins (STRING). SGO2 mRNA expression predicted higher grade gliomas than non-tumor brain tissues. Kaplan-Meier survival analysis showed that patients with high-grade gliomas with a higher SGO2 expression had worse survival outcomes. SGO2 mRNA and protein expression were upper regulated in gliomas than in normal brain tissue. Inhibition of SGO2 suppressed cell proliferation and migration. Also, PPI result showed SGO2 to be a potential hub protein, which was related to the expression of AURKB and FOXM1. SGO2 expression positively correlates with WHO pathological grading and patient survival, suggesting that SGO2 is a biomarker that is predictive of disease progression in patients with gliomas.

Implementation and performance evaluation of a drilling assistive device for distal locking of intramedullary nails.

Intramedullary nailing is a common treatment for long bone fractures. The nail might deform during implantation because of the shape of medullary cavity. Thus, surgeons take many X-ray images to position distal locking holes and check the drilling process. In this study, we developed a positioning algorithm with a passive or active (robot arm) assistive device for promptly positioning of distal locking holes and stably drilling guidance and support. Using the passive device, the surgeon could manually align the positioning probe with locking hole within 60 seconds based on 20 test cases. In 36 test cases, the active device aligned the positioning probe with locking hole automatically with average errors of 2.2 mm in position and 3.19° in direction. The passive device provides a reliable and low-cost solution for distal locking of intramedullary nails, while the active device is easy and friendly to use.

Transfemoral Approach for Intraoperative Angiography in the Prone or Three-quarter Prone Position : A Revisited Protocol for Intracranial Arteriovenous Malformation and Fistula Surgery.

PURPOSE: Among the different arterial accesses, the femoral access is the main approach for intraoperative angiography (IOA) performed in a prone position. Without a standardized protocol, however, the application of prone IOAs in intracranial arteriovenous malformation (AVM) or arteriovenous fistula (AVF) surgery remains limited by its procedural complexity. This study describes the detailed protocol for prone IOA through a transfemoral approach and highlights several refinements in preparing this procedure. METHODS: This study retrospectively reviewed the intracranial or high cervical AVM/AVF surgical cases in which both resection and IOA were performed in the prone or three-quarter prone position. Extended femoral sheath approaches and radiolucent head clamps were used in all cases. An aneurysm clip, serving as a localization landmark in IOA, was routinely placed within the surgical field. The IOA imaging, clinical impact of IOA, and complications related to the procedure were recorded. RESULTS: A total of six AVM and three AVF cases, operated on in the prone (n = 7) or three-quarter prone (n = 2) positions, were included. Multiple vessel injections were required in 66.7% of cases, and IOA was successfully performed in every intended vessel. All IOA images were adequate for interpretation, except for two cases in which the non-radiolucent component of the head clamp obscured the region of interest in the lateral views. Incomplete occlusion was identified in two patients, and the aneurysm clip provided precise guidance in localizing the residual nidus. Final IOA confirmed complete lesion removal in all cases, and there were no IOA-related complications. CONCLUSION: Three key steps in setting-up a prone IOA procedure for intracranial AVM/AVF surgery are proposed: (1) utilize an extended femoral sheath approach, (2) establish a localization landmark with an aneurysm clip and (3) avoid possible image interference from the non-radiolucent component of the head clamp.

Dynamic expression of SMAD3 is critical in osteoblast differentiation of PDMCs.

Human pluripotent stem cells have the potential assist in the identification of genes involved in mammalian development. The human placenta is considered a repository of stem cells, termed placenta­derived multipotent cells (PDMCs), which are able to differentiate into cells with an osteoblastic phenotype. This plasticity of PDMCs maybe applied clinically to the understanding of osteogenesis and osteoporosis. In the presentstudy, osteoblasts were generated by culturing PDMCs in osteogenic medium. Reverse transcription quantitative polymerase chain reactionand the degree of osteoblast calcification were used to evaluate the efficacy of osteogenesis. The results suggestedthat the expression of mothers against decapentaplegic homolog 3 (SMAD3) increased in the initial stages of osteogenic differentiation but decreased in the later stages. However, osteogenesis was inhibitedwhen the PDMCs overexpressed SMAD3 throughout the differentiation period. In addition, the rate of osteogenic differentiation was decreased when SMAD3 signaling was impaired. In conclusion, SMAD3 serves an important role in osteoblast differentiation and bone formation in a time­dependent manner. The data from the present study indicate that arapid increase in SMAD3 expression is crucial for osteogenesis and suggest a role for PDMCs in the treatment of patients with osteoporosis.

C-Arm Image-Based Surgical Path Planning Method for Distal Locking of Intramedullary Nails.

Due to the curvature of the bone marrow cavity, the intramedullary nail used in long bone fracture fixation can be deformed, causing displacement of the locking holes. In this study, an algorithm using only one C-arm image to determine the center positions and axial directions of locking holes was developed for drilling guidance. Based on conventional method that the axial direction of locking hole would be identified when locking hole contour is presented as a circle, the proposed method can locate the circle contour centroid by using one C-arm image including two elliptical contours. Then the two distal locking holes' axial direction and centers would be determined. Three experiments were conducted to verify the performance of the proposed algorithm, which are (1) computer simulation, (2) use of real intramedullary nails, and (3) actual drilling test with the bone model. The experimental results showed that the average error of the axial direction and center position were 0.62 ± 0.6°, 0.73 ± 0.53 mm (simulation) and 3.16 ± 1.36°, 1.10 ± 0.50 mm (actual nail), respectively. The last ten drilling test sets were completed successfully (with an average duration of 48 seconds). Based on the experimental results, the proposed algorithm was feasible for clinic applications.