Vascular compactness of unruptured brain arteriovenous malformation predicts risk of hemorrhage after stereotactic radiosurgery.

The aim of the study was to investigate whether morphology (i.e. compact/diffuse) of brain arteriovenous malformations (bAVMs) correlates with the incidence of hemorrhagic events in patients receiving Stereotactic Radiosurgery (SRS) for unruptured bAVMs. This retrospective study included 262 adult patients with unruptured bAVMs who underwent upfront SRS. Hemorrhagic events were defined as evidence of blood on CT or MRI. The morphology of bAVMs was evaluated using automated segmentation which calculated the proportion of vessel, brain tissue, and cerebrospinal fluid in bAVMs on T2-weighted MRI. Compactness index, defined as the ratio of vessel to brain tissue, categorized bAVMs into compact and diffuse types based on the optimal cutoff. Cox proportional hazard model was used to identify the independent factors for post-SRS hemorrhage. The median clinical follow-ups was 62.1 months. Post-SRS hemorrhage occurred in 13 (5.0%) patients and one of them had two bleeds, resulting in an annual bleeding rate of 0.8%. Multivariable analysis revealed bAVM morphology (compact versus diffuse), bAVM volume, and prescribed margin dose were significant predictors. The post-SRS hemorrhage rate increased with larger bAVM volume only among the diffuse nidi (1.7 versus 14.9 versus 30.6 hemorrhage per 1000 person-years in bAVM volume < 20 cm3 versus 20-40 cm3 versus > 40 cm3; p = 0.022). The significantly higher post-SRS hemorrhage rate of Spetzler-Martin grade IV-V compared with grade I-III bAVMs (20.0 versus 3.3 hemorrhages per 1000 person-years; p = 0.001) mainly originated from the diffuse bAVMs rather than the compact subgroup (30.9 versus 4.8 hemorrhages per 1000 person-years; p = 0.035). Compact and smaller bAVMs, with higher prescribed margin dose harbor lower risks of post-SRS hemorrhage. The post-SRS hemorrhage rate exceeded 2.2% annually within the diffuse and large (> 40 cm3) bAVMs and the diffuse Spetzler-Martin IV-V bAVMs. These findings may help guide patient selection of SRS for the unruptured bAVMs.

Risk, Predictive, and Preventive Factors for Noninfectious Ventriculitis and External Ventricular Drain Infection.

BACKGROUND: External ventricular drain (EVD) is used for monitoring intracranial pressure or diverting cerebrospinal fluid. However, confirmation of an infection is not immediate and requires obtaining culture results, often leading to the excessive use of antibiotics. This study aimed to compare noninfectious ventriculitis and EVD infection in terms of the risk factors, predictors, prognosis, and effectiveness of care bundle interventions. METHODS: This retrospective study was conducted at a medical center with 1,006 beds in northern Taiwan between January 2018 and July 2022. Standard EVD insertion protocols and care bundles have been implemented since 2018, along with the initiation of chlorhexidine. RESULTS: In total, 742 EVD cases were identified. Noninfectious ventriculitis typically presents with fever approximately 8 days following EVD placement, whereas EVD infection typically manifests as fever after 20 days. Aneurysmal subarachnoid hemorrhage was strongly associated with the development of noninfectious ventriculitis (adjusted odds ratio [OR] 2.6, 95% confidence interval [CI] 1.5-4.4). Alcoholism (adjusted OR 3.5, 95% CI 1.1-12.3) and arteriovenous malformation (adjusted OR 13.1, 95% CI 2.9-58.2) significantly increased the risk of EVD infection. The EVD infection rate significantly decreased from 3.6% (14 of 446) to 1.0% (3 of 219) (p = 0.03) after the implementation of chlorhexidine gluconate bathing. CONCLUSIONS: Aneurysmal subarachnoid hemorrhage or fever with neuroinflammation within 2 weeks of EVD placement is indicative of a higher likelihood of noninfectious ventriculitis. Conversely, patients with arteriovenous malformation, alcoholism, or fever with neuroinflammation occurring after more than 3 weeks of EVD placement are more likely to necessitate antibiotic treatment for EVD infection. Chlorhexidine gluconate bathing decreases EVD infection.

Delirium assessment tools among hospitalized older adults: A systematic review and metaanalysis of diagnostic accuracy.

Delirium is a common neuropsychiatric syndrome that is often overlooked in clinical settings. The most accurate instrument for screening delirium has not been established. This study aimed to compare the diagnostic accuracy of the 4 'A's Test (4AT), Nursing Delirium Screening Scale (Nu-DESC), and Confusion Assessment Method (CAM) in detecting delirium among older adults in clinical settings. These assessment tools feature concise item sets and straightforward administration procedures. Five electronic databases were systematically searched from their inception to September 7, 2022. Studies evaluating the sensitivity and specificity of the 4AT, Nu-DESC, and CAM against the Diagnostic and Statistical Manual of Mental Disorders or International Classification of Diseases as the reference standard were included. Bivariate random effects model was used to summarize the sensitivity and specificity results. A total of 38 studies involving 7378 patients were included. The 4AT, Nu-DESC, and CAM had comparable sensitivity in detecting delirium (0.76, 0.78, and 0.80, respectively). However, the specificity of the CAM was higher than that of the 4AT (0.98 vs 0.89, P = .01) and Nu-DESC 0.99 vs 0.90, P = .003). Diagnostic accuracy was moderated by the percentage of women, acute care setting, sample size, and assessors. The three tools exhibit comparable sensitivity, and the CAM has the highest specificity. Based on the feasibility of the tools, nurses and clinical staffs could employ the Nu-DESC and the 4AT on screening out positive delirium cases and integrate these tools into daily practice. Further investigations are warranted to verify our findings.

CFD Study of the Effect of the Angle Pattern on Iliac Vein Compression Syndrome.

Iliac vein compression syndrome (IVCS, or May-Thurner syndrome) occurs due to the compression of the left common iliac vein between the lumbar spine and right common iliac artery. Because most patients with compression are asymptomatic, the syndrome is difficult to diagnose based on the degree of anatomical compression. In this study, we investigated how the tilt angle of the left common iliac vein affects the flow patterns in the compressed blood vessel using three-dimensional computational fluid dynamic (CFD) simulations to determine the flow fields generated after compression sites. A patient-specific iliac venous CFD model was created to verify the boundary conditions and hemodynamic parameter set in this study. Thirty-one patient-specific CFD models with various iliac venous angles were developed using computed tomography (CT) angiograms. The angles between the right or left common iliac vein and inferior vena cava at the confluence level of the common iliac vein were defined as α1 and α2. Flow fields and vortex locations after compression were calculated and compared according to the tilt angle of the veins. Our results showed that α2 affected the incidence of flow field disturbance. At α2 angles greater than 60 degrees, the incidence rate of blood flow disturbance was 90%. In addition, when α2 and α1 + α2 angles were used as indicators, significant differences in tilt angle were found between veins with laminar, transitional, and turbulent flow (p < 0.05). Using this mathematical simulation, we concluded that the tilt angle of the left common iliac vein can be used as an auxiliary indicator to determine IVCS and its severity, and as a reference for clinical decision making.

NADPH Oxidase Subunit CYBB Confers Chemotherapy and Ferroptosis Resistance in Mesenchymal Glioblastoma via Nrf2/SOD2 Modulation.

Glioblastoma multiforme (GBM) is a highly heterogeneous disease with a mesenchymal subtype tending to exhibit more aggressive and multitherapy-resistant features. Glioblastoma stem-cells derived from mesenchymal cells are reliant on iron supply, accumulated with high reactive oxygen species (ROS), and susceptible to ferroptosis. Temozolomide (TMZ) treatment is the mainstay drug for GBM despite the rapid development of resistance in mesenchymal GBM. The main interconnection between mesenchymal features, TMZ resistance, and ferroptosis are poorly understood. Herein, we demonstrated that a subunit of NADPH oxidase, CYBB, orchestrated mesenchymal shift and promoted TMZ resistance by modulating the anti-ferroptosis circuitry Nrf2/SOD2 axis. Public transcriptomic data re-analysis found that CYBB and SOD2 were highly upregulated in the mesenchymal subtype of GBM. Accordingly, our GBM cohort confirmed a high expression of CYBB in the GBM tumor and was associated with mesenchymal features and poor clinical outcome. An in vitro study demonstrated that TMZ-resistant GBM cells displayed mesenchymal and stemness features while remaining resilient to erastin-mediated ferroptosis by activating the CYBB/Nrf2/SOD2 axis. The CYBB maintained a high ROS state to sustain the mesenchymal phenotype, TMZ resistance, and reduced erastin sensitivity. Mechanistically, CYBB interacted with Nrf2 and consequently regulated SOD2 transcription. Compensatory antioxidant SOD2 essentially protected against the deleterious effect of high ROS while attenuating ferroptosis in TMZ-resistant cells. An animal study highlighted the protective role of SOD2 to mitigate erastin-triggered ferroptosis and tolerate oxidative stress burden in mice harboring TMZ-resistant GBM cell xenografts. Therefore, CYBB captured ferroptosis resilience in mesenchymal GBM. The downstream compensatory activity of CYBB via the Nrf2/SOD2 axis is exploitable through erastin-induced ferroptosis to overcome TMZ resistance.

Effects of Neurofeedback on Cognitive Function, Productive Activity, and Quality of Life in Patients With Traumatic Brain Injury: A Randomized Controlled Trial.

BACKGROUND: Cognitive impairment is common in patients with traumatic brain injury (TBI). Studies that have examined the effectiveness of neurofeedback (NFB) on cognitive function following TBI have had poor study designs and small sample sizes. OBJECTIVES: This randomized controlled trial assessed the effects of low-resolution tomography Z-score NFB (LZNFB) and theta/beta NFB on cognitive impairment, return to productive activity, and quality of life in patients with TBI. METHODS: We randomly assigned 87 patients with TBI with cognitive impairment to LZNFB, theta/beta NFB, or usual care (UC) groups. Patients in both NFB groups received weekly 60-minute treatment for 10 weeks, and those in the control group received UC and telephone interviews for 10 weeks. The primary outcome was cognitive function as measured by performance on cognitive tasks; the secondary outcomes included productive activity and quality of life based on the Community Integration Questionnaire-revised (CIQ-R) and the Quality of Life after Brain Injury (QOLIBRI), respectively, at baseline and immediately after the last intervention. RESULTS: The LZNFB group exhibited significantly greater improvements in immediate recall, delayed recall, recognition memory, and selective attention compared with the UC group; the theta/beta NFB group exhibited improvements in only immediate memory and selective attention (P < .05). The total CIQ-R scores of the LZNFB group after treatment were significantly improved than those of the UC group were. CONCLUSION: Consecutive LZNFB achieved therapeutic effects in memory, attention, and productive activity, whereas theta/beta NFB improved memory and attention in patients with TBI.This trial was prospectively registered at ClinicalTrial.gov (registration number: NCT03515317; https://clinicaltrials.gov/ct2/show/NCT03515317).

Case report: A hybrid open and endovascular approach for repairing a life-threatening innominate artery dissection using the simultaneous kissing stent technique.

Managing acute innominate artery (IA) dissection associated with severe stenosis is challenging due to its rarity, possible complex dissection patterns, and compromised blood flow to the brain and upper extremities. This report describes our treatment strategy for this challenging disease using the kissing stent technique. A 61-year-old man had worsening of an acute IA dissection secondary to an extension of a treated aortic dissection. Four possible treatment strategies for kissing stent placement were proposed based on different approaches (open surgical or endovascular) and accesses (trans-femoral, trans-brachial, or trans-carotid access). We chose to place two stents simultaneously via a percutaneous retrograde endovascular approach through the right brachial artery and a combined open surgical distal clamping of the common carotid artery with a retrograde endovascular approach through the carotid artery. This hybrid approach strategy highlights the three key points for maintaining safety and efficacy: (1) good guiding catheter support is obtainable through retrograde, rather than antegrade, access to the lesion, (2) concomitant cerebral and upper extremity reperfusion is guaranteed by placing kissing stents into the IA, and (3) peri-procedural cerebral emboli are prevented by surgical exposure of the common carotid artery with distal clamping.

Compactness index: a radiosurgery outcome predictor for patients with unruptured brain arteriovenous malformations.

OBJECTIVE: The goal of the study was to define and quantify brain arteriovenous malformation (bAVM) compactness and to assess its effect on outcomes after Gamma Knife radiosurgery (GKRS) for unruptured bAVMs. METHODS: Unsupervised machine learning with fuzzy c-means clustering was used to differentiate the tissue constituents of bAVMs on T2-weighted MR images. The percentages of vessel, brain, and CSF were quantified. The proposed compactness index, defined as the ratio of vasculature tissue to brain tissue, categorized bAVM morphology into compact, intermediate, and diffuse types according to the tertiles of this index. The outcomes of interest were complete obliteration and radiation-induced changes (RICs). RESULTS: A total of 209 unruptured bAVMs treated with GKRS were retrospectively included. The median imaging and clinical follow-up periods were 49.2 and 72.3 months, respectively. One hundred seventy-three bAVMs (82.8%) achieved complete obliteration after a median latency period of 43.3 months. The rates of RIC and permanent RIC were 76.1% and 3.8%, respectively. Post-GKRS hemorrhage occurred in 14 patients (6.7%), resulting in an annual bleeding risk of 1.0%. Compact bAVM, smaller bAVM volume, and exclusively superficial venous drainage were independent predictors of complete obliteration. Diffuse bAVM morphology, larger bAVM volume, and higher margin dose were independently associated with RICs. CONCLUSIONS: The compactness index quantitatively describes the compactness of unruptured bAVMs. Moreover, compact bAVMs may have a higher obliteration rate and a smaller risk of RICs than diffuse bAVMs. This finding could help guide decision-making regarding GKRS treatment for patients with unruptured bAVMs.

Three-Dimensional Angioarchitecture of Rete Middle Cerebral Artery Anomalies and the Clinical Significance.

PURPOSE: Rete middle cerebral artery (MCA) anomaly is characterized by a web-like network of arteries involving the first MCA segment (M1) and a normal downstream MCA. The detailed composition of this anomaly and the hemodynamic impacts on cerebral perfusion are rarely addressed. The purpose of this study was to elucidate the anatomical and hemodynamic perspectives of the rete MCA anomaly. METHODS: From August 2020 to December 2021, 4 rete MCA anomalies were identified at Shuang Ho hospital. Clinical information, perfusion magnetic resonance (MR) imaging, and angiographic images were collected. Detailed angioarchitecture, including types of arterial feeders and extent of rete involvement, were analyzed based on three-dimensional volume-rendering reconstruction images obtained from the catheter-based angiographies. RESULTS: Despite their variable clinical presentations (two hemorrhage, one ischemia, and one asymptomatic), all cases shared common angiographic findings as follows: (1) the internal carotid artery did not connect directly to the rete, (2) the anterior choroidal artery (AChA) was the artery constantly supplying the rete and (3) there was a watershed zone shift toward MCA territory. The perfusion MR cerebral blood flow map was symmetric in all studied cases. CONCLUSION: The AChA is an artery constantly supplying the rete, which suggests that the angioarchitectural features associated with this anomaly may be the result of both congenital and acquired compensatory processes. Cerebral perfusion remains preserved at the lesion side, despite angiographic evidence of watershed zone shift. These findings will be important for making better clinical judgments about this condition.

Ubiquitin-Specific Protease 6 n-Terminal-like Protein (USP6NL) and the Epidermal Growth Factor Receptor (EGFR) Signaling Axis Regulates Ubiquitin-Mediated DNA Repair and Temozolomide-Resistance in Glioblastoma.

Glioblastoma multiforme (GBM) is the most malignant glioma, with a 30-60% epidermal growth factor receptor (EGFR) mutation. This mutation is associated with unrestricted cell growth and increases the possibility of cancer invasion. Patients with EGFR-mutated GBM often develop resistance to the available treatment modalities and higher recurrence rates. The drug resistance observed is associated with multiple genetic or epigenetic factors. The ubiquitin-specific protease 6 N-terminal-like protein (USP6NL) is a GTPase-activating protein that functions as a deubiquitinating enzyme and regulates endocytosis and signal transduction. It is highly expressed in many cancer types and may promote the growth and proliferation of cancer cells. We hypothesized that USP6NL affects GBM chemoresistance and tumorigenesis, and that its inhibition may be a novel therapeutic strategy for GBM treatment. The USP6NL level, together with EGFR expression in human GBM tissue samples and cell lines associated with therapy resistance, tumor growth, and cancer invasion, were investigated. Its pivotal roles and potential mechanism in modulating tumor growth, and the key mechanism associated with therapy resistance of GBM cells, were studied, both in vitro and in vivo. Herein, we found that deubiquitinase USP6NL and growth factor receptor EGFR were strongly associated with the oncogenicity and resistance of GBM, both in vitro and in vivo, toward temozolomide, as evidenced by enhanced migration, invasion, and acquisition of a highly invasive and drug-resistant phenotype by the GBM cells. Furthermore, abrogation of USP6NL reversed the properties of GBM cells and resensitized them toward temozolomide by enhancing autophagy and reducing the DNA damage repair response. Our results provide novel insights into the probable mechanism through which USP6NL/EGFR signaling might suppress the anticancer therapeutic response, induce cancer invasiveness, and facilitate reduced sensitivity to temozolomide treatment in GBM in an autolysosome-dependent manner. Therefore, controlling the USP6NL may offer an alternative, but efficient, therapeutic strategy for targeting and eradicating otherwise resistant and recurrent phenotypes of aggressive GBM cells.

Learning Curve of ROSA ONE Spine System for Transpedicular Screw Placement.

OBJECTIVE: The study investigated our institutional learning curve for the ROSA ONE spine system (ROSA) based on ROSA usage time. METHODS: ROSA was designed to provide high accuracy for spinal pedicle screw placement through a built-in tracking technique. This study was conducted from November 2018 to January 2021. The time taken to complete each step of the robotic workflow was recorded. Patient demographics, comorbidities, surgical indications, and number of screw placements were examined in subgroup analysis. The Curve Fitting-General package (a part of NCSS 2021 software) was used to fit a mathematical model to the learning curve. Patient demographics, imaging data, and surgical time were reviewed retrospectively. RESULTS: A total of 167 patients who had undergone surgery were included. The mean total ROSA usage time was 107.1 ± 27.3 minutes. The estimated learning rate was 90.4%, and the largest slope change occurred close to the time of the 20th surgery. The observed overall learning trend in the 4-screw group could be attributed to screw planning. The presence of scoliosis (p = 0.73) or spondylolisthesis (p = 0.70) did not significantly influence the mean total time (TT) for all patients; however, the mean TT differed significantly (p < 0.01) among subgroups stratified by body mass index, screw number placement, and thoracic spine involvement. CONCLUSION: To the best of our knowledge, this is the first study to examine the learning curve for the various crucial steps of ROSA-guided pedicle screw placement. The indicative learning curve involved 20 patients who had undergone surgery.

Number of cerebral microbleeds after intracranial/extracranial stenting and dual antiplatelet therapy.

BACKGROUND: Cerebral microbleeds (CMBs) are small (<1 cm) perivascular hemosiderin depositions. They may be visible in T2* or susceptibility-weighted magnetic resonance imaging (MRI) sequences. CMBs may indicate an increased risk of intracerebral hemorrhage (ICH) or vascular disease. Cerebral white matter changes indicate small vessel disease (SVD), which is also related to CMBs. In cerebral vascular treatment, dual antiplatelet therapy (DAPT) is routinely used after stenting. We surveyed our cerebral stenting case series for changes in the number of CMBs. METHODS: Patients receiving extracranial or intracranial stenting between 2018 and 2020 were included. All patients received DAPT after stenting. Changes in CMBs, SVD degree, and other findings from pretreatment to follow-up MRI were recorded. Differences between stented artery supplying territory and other territories were compared. RESULTS: The average age of the 75 enrolled patients was 65.37 years ± 11.53 (50 male and 25 female patients); 84 extracranial or intracranial stentings were performed. The average Fazekas scale score was 1.32 ± 0.77. Significantly more CMBs developed in the initial ≥6 CMB group than in the initial 0 and 1-5 CMB groups (7 ± 3.6 vs 0.56 ± 1.06, 1.45 ± 3.32, p < 0.001). No significant difference in increased CMBs was observed between the initial 0 and 1-5 CMB groups. Significantly more CMBs developed in the stented artery supplying territory than elsewhere (0.6 ± 0.13 vs 0.44 ± 0.17, p < 0.05). No ICH was noted in our case series. CONCLUSION: Preexisting CMB was a risk factor for the onset of new CMBs after stenting and DAPT. Poststenting and DAPT statistically increased CMBs in stented artery supplying territories at short-term follow-up.

Combined Treatment with Acalabrutinib and Rapamycin Inhibits Glioma Stem Cells and Promotes Vascular Normalization by Downregulating BTK/mTOR/VEGF Signaling.

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults, with a median duration of survival of approximately 14 months after diagnosis. High resistance to chemotherapy remains a major problem. Previously, BTK has been shown to be involved in the intracellular signal transduction including Akt/mTOR signaling and be critical for tumorigenesis. Thus, we aim to evaluate the effect of BTK and mTOR inhibition in GBM. We evaluated the viability of GBM cell lines after treatment with acalabrutinib and/or rapamycin through a SRB staining assay. We then evaluated the effect of both drugs on GBM stem cell-like phenotypes through various in vitro assay. Furthermore, we incubated HUVEC cells with tumorsphere conditioned media and observed their angiogenesis potential, with or without treatment. Finally, we conducted an in vivo study to confirm our in vitro findings and analyzed the effect of this combination on xenograft mice models. Drug combination assay demonstrated a synergistic relationship between acalabrutinib and rapamycin. CSCs phenotypes, including tumorsphere and colony formation with the associated expression of markers of pluripotency are inhibited by either acalabrutinib or rapamycin singly and these effects are enhanced upon combining acalabrutinib and rapamycin. We showed that the angiogenesis capabilities of HUVEC cells are significantly reduced after treatment with acalabrutinib and/or rapamycin. Xenograft tumors treated with both drugs showed significant volume reduction with minimal toxicity. Samples taken from the combined treatment group demonstrated an increased Desmin/CD31 and col IV/vessel ratio, suggesting an increased rate of vascular normalization. Our results demonstrate that BTK-mTOR inhibition disrupts the population of GBM-CSCs and contributes to normalizing GBM vascularization and thus, may serve as a basis for developing therapeutic strategies for chemoresistant/radioresistant GBM.

Adjunctive efficacy of intra-arterial cone-beam computed tomography angiography in the endovascular treatment of vertebra-venous fistula.

Vertebro-venous fistula (VVF) refers to an abnormal arteriovenous shunt connecting the extracranial vertebral artery and the paraspinal venous structures. Coil embolization is the mainstay treatment of choice for VVF, and accurate definition of the endovascular target is mandatory. Traditionally, catheter-based angiograms are used for treatment planning, but those images lack bony information to delineate the precise relationship of the drainage veins to the spinal structure. Herein, we presented two VVF cases and demonstrated how we used intra-arterial cone-beam computed tomography angiography (IA-CBCTA) to determine the safe embolization zone for dense coil packing. We propose that IA-CBCTA is a useful adjunct in the endovascular planning of VVF by offering an image consisting of bony and vascular information.

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.

Cycloheterophyllin Inhibits the Release of Glutamate from Nerve Terminals of the Rat Hippocampus.

The effect of cycloheterophyllin, a prenylflavone isolated from Artocarpus heteophyllus, on glutamate release was studied in the rat hippocampus using synaptosome and slice preparations. In rat hippocampal synaptosomes, cycloheterophyllin inhibited 4-aminopyridine (4-AP)-evoked glutamate release and elevation of intrasynaptosomal calcium levels. The inhibitory effect of cycloheterophyllin on 4-AP-evoked glutamate release was prevented in the presence of the vesicular transporter inhibitor, the N- and P/Q-type calcium channel blocker, and the protein kinase C (PKC) inhibitor but was insensitive to the intracellular Ca2+ release inhibitors, the protein kinase A inhibitor, and the mitogen-activated/extracellular signal-regulated kinase inhibitor. Western blotting data in synaptosomes also showed that cycloheterophyllin significantly decreased the level of phosphorylation of PKC. In addition, cycloheterophyllin decreased the frequency of spontaneous excitatory postsynaptic currents (sEPSCs) without influencing the amplitude of sEPSCs and glutamate-activated currents in hippocampal slices, supporting a presynaptic action. Together, these results suggest that cycloheterophyllin inhibits presynaptic glutamate release by suppressing N- and P/Q-type calcium channel and PKC activity in the rat hippocampus.

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.

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.

Accuracy and Safety of Using Customized Guiding Templates for Cervical Pedicle Screw Insertion in Severe Cervical Deformity, Fracture, and Subluxation: A Retrospective Study of 9 Cases.

OBJECTIVE: To assess accuracy and safety of self-developed customized guiding templates for cervical pedicle screw (CPS) insertion surgery. METHODS: From July 2016 to December 2017, 57 screws were implanted in 9 patients with the assistance of customized guiding templates. Customized guiding templates were manufactured from acrylonitrile-butadiene-styrene plastic material using a three-dimensional printer after establishing pedicle screw trajectories for each vertebra with the assistance of a virtual surgical planning software program, developed by our team, for the insertion of CPSs. RESULTS: CPSs were evaluated using the following grading system: grade 0 (contained), grade 1 (exposure), grade 2 (perforation), and grade 3 (penetration). Each patient underwent postoperative computed tomography to evaluate accuracy of screw position. Of 57 screws, 54 were graded 0, and 3 were graded 1; no screws were graded 2 or 3. No vascular or nerve injuries were noted after the operations. CONCLUSIONS: CPSs, which provide strong biologic strength, are especially suitable for treating osteoporosis and severe deformity. However, CPS insertion remains a challenging procedure with high incidences of vascular and nerve injuries reported. The results of this study indicate that use of customized guiding templates can improve safety of CPS insertion surgery.