RETRACTED: Exploring the mechanism by which accumbal deep brain stimulation attenuates morphine-induced reinstatement through manganese-enhanced MRI and pharmacological intervention.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the authors. The authors have requested to retract this paper as the corresponding author had not sought the prior agreement of his co-authors to submit the paper for publication.

Sensitivity of power and RMS delay spread predictions of a 3D indoor ray tracing model.

This study investigates the sensitivity of a three-dimensional (3D) indoor ray tracing (RT) model for the use of the uniform theory of diffraction and geometrical optics in radio channel characterizations of indoor environments. Under complex indoor environments, RT-based predictions require detailed and accurate databases of indoor object layouts and the electrical characteristics of such environments. The aim of this study is to assist in selecting the appropriate level of accuracy required in indoor databases to achieve good trade-offs between database costs and prediction accuracy. This study focuses on the effects of errors in indoor environments on prediction results. In studying the effects of inaccuracies in geometry information (indoor object layout) on power coverage prediction, two types of artificial erroneous indoor maps are used. Moreover, a systematic analysis is performed by comparing the predictions with erroneous indoor maps and those with the original indoor map. Subsequently, the influence of random errors on RMS delay spread results is investigated. Given the effect of electrical parameters on the accuracy of the predicted results of the 3D RT model, the relative permittivity and conductivity of different fractions of an indoor environment are set with different values. Five types of computer simulations are considered, and for each type, the received power and RMS delay spread under the same circumstances are simulated with the RT model.

Embolization of dural arteriovenous fistula of the anterior cranial fossa through the middle meningeal artery with Onyx.

OBJECTIVE: Dural arteriovenous fistula (DAVF) of the anterior cranial fossa is usually treated by surgical disconnection or endovascular embolization via the ophthalmic artery. The middle meningeal artery is a rarely used approach. This study investigated the safety and efficacy of embolization of DAVF of the anterior cranial fossa with Onyx through the middle meningeal artery. METHODS: A retrospective review of a prospective cerebral vascular disease database was performed. Patients with DAVF of the anterior cranial fossa managed with embolization through the middle meningeal artery with Onyx were selected. Information on demography, symptoms and signs, angiographic examinations, interventional treatments, angiographic and clinical results, and follow-up was collected and analyzed. RESULTS: Five patients were included in this study, four of whom had hemorrhage. All fistulas were fed by the bilateral ethmoidal arteries arising from the ophthalmic artery and by the anterior branch of the middle meningeal artery. The abnormal shunt unilaterally drained into the superior sagittal sinus with interposition of the cortical veins all five patients. All endovascular treatments were successful with evidence of an angiographic cure. No complications occurred, and all patients recovered uneventfully without neurologic deficits. There were nearly no symptoms among the patients during follow-up. CONCLUSION: Embolization of DAVF of the anterior cranial fossa via the middle meningeal artery with Onyx is safe, effective, and a good choice for management of DAVF. More cases are needed to verify these findings.

Treatment of dural arteriovenous fistula by balloon-assisted transarterial embolization with Onyx.

OBJECTIVE: This study evaluated the feasibility, safety, and efficacy of embolization of dural arteriovenous fistula via a very small, short feeding artery with the assistance of a balloon placed proximal to the tip of the microcatheter, such that the balloon serves as a plug. METHODS: Eight patients who underwent treatment of DAVF by balloon-assisted transarterial embolization with Onyx were retrospectively reviewed. Gender, age, angiography findings, procedure details, clinical and angiographic outcomes, complications, and follow-up were recorded and analyzed. RESULTS: Nine embolization procedures were performed in eight male patients via extracranial arteries. Balloon-assisted embolization was successful in all eight patients. A Hyperglide balloon was used in five patients, and a Hyperform balloon was used in three patients. Angiographic resolution of the fistula was achieved in all patients without complications. All patients recovered uneventfully. During the follow-up period of 7-19 months, all patients were asymptomatic except for one patient who experienced mild headaches. CONCLUSIONS: Treatment of DAVF by balloon-assisted embolization with Onyx achieved promising results, even in patients with very small and short feeding arteries. This technique allowed the treatment of DAVF cases where other techniques have failed.

Wingspan stent for high-grade symptomatic vertebrobasilar artery atherosclerotic stenosis.

PURPOSE: This study was designed to present the treatment outcomes with Wingspan stent angioplasty of high-grade intracranial vertebrobasilar artery (VBA) stenosis in symptomatic patients. METHODS: Between 2007 and 2010, the records of 30 patients with 31 intracranial high-grade VBA stenoses (all ≥ 70%) who underwent elective stenting due to the failure of medical therapy were retrospectively reviewed. Clinical evaluation was performed based on the modified Rankin scale and the National Institutes of Health Stroke Scale. RESULTS: In all cases, the stent deployment was technically successful. The mean stenosis decreased significantly from 82.28 ± 8.02% (range, 72-99%) to 11.18 ± 7.28% (range, 0-25%) after stent-assisted angioplasty (P < 0.05). Periprocedure complications occurred in 3 (10%) of 30 patients; there were 2 cases of perforator strokes and 1 case of transient flow insufficiency with stent overlap. Clinical follow-up (mean, 17.81 ± 11.49 months; range, 5-40 months) was available for 27 patients, and angiographic follow-up (mean, 9.95 ± 5.74 months, range, 5-20 months) was available for 19 patients. Only one case demonstrated recurrent symptoms with restenosis (≥ 50%). There were no recurrent ischemic events and no cases of restenosis in the other patients. CONCLUSIONS: According to our data, the Wingspan stent for symptomatic intracranial VBA stenoses is a safe and efficacious treatment alternative in cases with recurrent symptoms despite medical therapy. However, the improvement of outcome requires the reduction in the rate of procedure-related complications and long-term outcomes still have to be demonstrated.

Potential role of Jun activation domain-binding protein 1 and phosphorylated p27 expression in prognosis of glioma.

To investigate whether Jun activation domain-binding protein 1 (Jab1) expression is correlated with p27 protein and its phosphorylation status as well as how it might be clinically relevant in glioma, we carried out an immunohistochemical study of Jab1, Ser10-phosphorylated p27 (pSer10p27), and p27 using biopsies from 192 patients with primary glioma. Kaplan-Meier survival and Cox regression analyses were performed to evaluate the prognosis of patients. Immunostaining revealed a positive correlation between Jab1 and cytoplasmic p27 as well as pSer10p27 in all glioma cases. In addition, patients displaying the overexpression of Jab1, cytoplasmic p27, and pSer10p27 were significantly associated with unfavorable clinicopathological variables. Statistical analysis showed that patients expressing Jab1, cytoplasmic p27, and pSer10p27 have poor overall survival rates relative to those not expressing these proteins. Cox multifactor analysis showed that Jab1 (P = 0.006), cytoplasmic p27 (P = 0.01), and pSer10p27 (P = 0.009) were independent prognosis factors for human glioma. In conclusion, the current results showed convincing evidence that the overexpression of Jab1, cytoplasmic p27, and pSer10p27 proteins is correlated with poor outcome in patients with glioma and that these three proteins may be useful markers to predict the prognosis of this tumor.

Gypenosides improve cognitive impairment induced by chronic cerebral hypoperfusion in rats by suppressing oxidative stress and astrocytic activation.

Gypenosides (GP), the saponin extract derived from the Gynostemma pentaphyllum Makino, a widely reputed medicinal plant in China, has been reported to have some neuroprotective effects. We used a rat model of chronic cerebral hypoperfusion to investigate the protective effects of GP on the cortex and hippocampal CA1 region and the underlying mechanisms for its inhibition of cognitive decline. Daily doses of 100 and 200 mg/kg GP were orally administered to adult male Sprague-Dawley rats for 61 days after inducing cerebral hypoperfusion experimentally, and spatial learning and memory were assessed using the Morris water maze. Antioxidative capability was measured biochemically. The levels of lipid peroxidation and oxidative DNA damage were assessed by immunohistochemical staining for 4-hydroxynonenal and 8-hydroxy-2'-deoxyguanosine, respectively. Activated astrocytes were assessed by immunohistochemical staining and western blotting with GFAP antibodies. Rats receiving 200 mg/kg GP had better spatial learning and memory than saline-treated rats. GP 200 mg/kg/day were found to markedly enhance antioxidant abilities, decrease lipid peroxide products and oxidative DNA damage, and reduce the activation of inflammatory astrocytes. However, GP 100 mg/kg had no significant effects. GP may have therapeutic potential for the treatment of dementia induced by chronic cerebral hypoperfusion and further evaluation is warranted.

Reduced expression of SMAD4 in gliomas correlates with progression and survival of patients.

BACKGROUND: To examine the expression of SMAD4 at gene and protein levels in glioma samples with different WHO grades and its association with survival. METHODS: Two hundreds fifty-two glioma specimens and 42 normal control tissues were collected. Immunochemistry assay, quantitative real-time PCR and Western blot analysis were carried out to investigate the expression of SMAD4. Kaplan-Meier method and Cox's proportional hazards model were used in survival analysis. RESULTS: Immunohistochemistry showed that SMAD4 expression was decreased in glioma. SMAD4 mRNA and protein levels were both lower in glioma compared to control on real-time PCR and Western blot analysis (both P < 0.001). In addition, its expression levels decrease from grade I to grade IV glioma according to the results of real-time PCR, immunohistochemistry analysis and Western blot. Moreover, the survival rate of SMAD4-positive patients was higher than that of SMAD4-negative patients. We further confirmed that the loss of SMAD4 was a significant and independent prognostic indicator in glioma by multivariate analysis. CONCLUSIONS: Our data provides convincing evidence for the first time that the reduced expression of SMAD4 at gene and protein levels is correlated with poor outcome in patients with glioma. SMAD4 may play an inhibitive role during the development of glioma and may be a potential prognosis predictor of glioma.

Intraarterial thrombolysis and stent placement for acute basilar artery occlusion.

PURPOSE: To study retrospectively the prognostic factors for acute basilar artery occlusion treated with intraarterial thrombolysis and stent placement. MATERIALS AND METHODS: Within 3-48 hours of disease onset, 52 patients with basilar artery occlusion were treated with emergency intraarterial thrombolysis with recombinant tissue plasminogen activator (rtPA) or urokinase (UK) or intraarterial thrombolysis combined with stent placement. Sixteen patients simultaneously received stent placement for the partial recanalization of basilar artery occlusion after intraarterial thrombolysis. The National Institutes of Health Stroke Scale (NIHSS) scores and the modified Rankin Scale (mRS) scores of the patients were estimated. RESULTS: A favorable clinical outcome occurred in 22 patients (42.3%), and 20 patients (38.5%) died. The survival rate was 61.5% (32 patients). Successful recanalization of basilar artery occlusion was achieved in 24 patients (46.2%), and partial recanalization was achieved in 16 patients (30.7%). The rate of recanalization was 76.9%. NIHSS scores less than 14, treatment time window less than 24 hours, and a good recanalization were markedly correlated with good clinical prognosis. NIHSS scores less than 14 and treatment time window less than 24 hours were significantly correlated with recanalization. NIHSS scores less than 14 and good recanalization could act as independent predictors for clinical prognosis. CONCLUSIONS: NIHSS scores less than 14 on admission and successful recanalization can predict favorable outcome for patients with basilar artery occlusion. This study shows that intraarterial thrombolysis and stent placement may be a useful treatment for acute basilar artery occlusion.

Astragaloside IV attenuates cerebral ischemia-reperfusion-induced increase in permeability of the blood-brain barrier in rats.

Astragalus membranaceus is widely used to treat stroke and chronic debilitating diseases in China, but the mechanism has not been fully demonstrated to data. In the present study, we, using astragaloside IV, a purified extract from astragalus membranaceus, to a focal cerebral ischemia/reperfusion rat model, aimed to investigate the effect of astragaloside IV on the permeability of the blood-brain barrier since disruption of blood-brain barrier induced by ischemia/reperfusion leads to serious brain injuries. We found that astragaloside IV (10, 20 mg/kg) significantly attenuated the permeability of blood-brain barrier in comparison with vehicle group after ischemia/reperfusion assessed via Evans blue leakage (P<0.05). This was further confirmed by examination of blood-brain barrier permeability under the electron microscope, using lanthanum as a tracer of blood vessel permeability. Lanthanum was usually found within the blood vessel in sham group, rather than in perivascular tissues as shown in vehicle group. In drug groups, lanthanum stain was mainly restricted within the cerebral capillary, indicating the potential protective effect of astragaloside IV on the integrity of blood-brain barrier in ischemia/reperfusion rats. Furthermore, we found that expression of occludin and zonae occludens-1 (ZO-1), the tight junction proteins, was decreased in endothelial cells in vehicle group, which, however, could be reversed by astragaloside IV administration. We propose that regulation of tight junctional proteins in the endothelial cells may be one mechanism astragaloside IV-mediated in attribution to blood-brain barrier protection in the ischemia/reperfusion rats.

Intracranial angioplasty with Gateway-Wingspan system for symptomatic atherosclerotic stenosis: preliminary results of 27 Chinese patients.

BACKGROUND: We investigated the safety of treatment of symptomatic intracranial atherosclerotic stenoses with the Gateway-Wingspan system and its initial effect on prevention of ischemic events. METHODS: Twenty-seven cases of symptomatic intracranial atherosclerotic stenoses were treated with angioplasty with a Wingspan stent. Location of stenoses, extent of stenoses before and after angioplasty, success rate of treatment, occurrence of procedural complications, and changes in recurrence of symptoms of ischemic events 30 days after treatment were recorded. RESULTS: Twenty-nine angioplasties with the Wingspan system were successfully carried out in 29 stenoses in 27 patients. Of 29 stenoses, 17 were in the posterior circulation, and 12, in the anterior circulation. The degree of stenoses was reduced from baseline 71.8% (56%-87.8%) to 24.9% (0%-45%) after stenting. Complications were seen in four patients (14.8%), 3 of which were lesion-related infarction of a perforated artery, and 1 was a non-lesion-related infarction. Two complications led to transient neurologic dysfunction, one led to defect of the visual field, and one led to hemiplegia. The prevalence of morbidity and serious morbidity were 7.4% and 3.7%, respectively, and no death occurred. No new ischemic events happened during 30 days after stenting. CONCLUSION: Angioplasty with the Wingspan system to treat symptomatic intracranial atherosclerotic stenoses appears to be safe. Its initial effect on prevention of ischemic events is acceptable.

Inhibition of transcription factor STAT5b suppresses proliferation, induces G1 cell cycle arrest and reduces tumor cell invasion in human glioblastoma multiforme cells.

Abnormalities in the signal transducer and activator of transcription 5 (STAT5) signaling are involved in the oncogenesis of several cancers. However, previous studies have not elucidated clear and distinct roles for each STAT5 gene in cancers. To investigate the role of STAT5a, -5b isoforms in human glioblastoma multiforme (GBM) progression, we depleted each STAT5 isoforms with siRNA. Our results demonstrate that STAT5b is involved in GBM cell growth, cell cycle progression, invasion and migration through regulation of gene expression, such as Bcl-2, p21(waf1/cip1), p27(kip1), FAK and VEGF. Moreover, immunohistochemical staining reveals that cytoplasm staining of STAT5b is markedly increased in GBM (57.1%) compared with that in normal cortex (22.2%) and diffuse astrocytoma (27.3%), suggesting that STAT5b could have important implications in astrocytoma biology. Therefore, our findings illustrate the biological significance of STAT5b in GBM progression, and provide novel evidence that STAT5b may serve as a therapeutic target in the prevention of human glioblastoma multiforme.

Nigrostriatal projecting neurons express GDNF receptor subunit RET in adult rats.

Nigrostriatal neurons expressing RET protein, a receptor protein tyrosine kinase of glial cell line-derived neurotrophic factor (GDNF) were investigated in rats using retrograde neural tracing with horseradish peroxidase (HRP) combined with immunohistochemistry. HR/RET double-labeled neurons were abundantly distributed in the substantia nigra pars compacta ipsilateral to the caudate-putamen stereotaxically injected with HRP. Almost all the HRP-labeled neurons in nigra exhibited RET-like immunoreactivity, which however constituted more than half of the RET-immunoreactive cells. Our results present morphological evidence that GDNF-RET interaction plays important roles in physiological processes of nigrostriatal neuronal circuits of mammals.

Repeat gamma knife radiosurgery for recurrent or refractory trigeminal neuralgia.

BACKGROUND: Repeat gamma knife radiosurgery (GKRS) is considered to be an effective treatment for refractory or recurrent trigeminal neuralgia (TN). AIMS: The purpose of this report was to demonstrate the relationship between the outcome of repeat GKRS and prior operative procedures on patients with recurrent or refractory TN. MATERIALS AND METHODS: A retrospective analysis was performed on 34 patients with refractory or recurrent TN who had undergone repeat GKRS; 21 patients had undergone other types of procedures, 11 of whom had undergone more than three such procedures prior to radiosurgery. The maximum dose of the repeat procedure was between 60 and 75 Gy. The mean follow-up time was 21.6 months. STATISTICAL ANALYSIS USED: The log-rank test and Fisher's exact test were used to analyze the data. RESULTS: Excellent pain relief was achieved in 14 patients (41.2%) after repeat GKRS, while a successful outcome occurred in 29 of 34 patients (85.3%). Better pain relief occurred in the patients who did not have a prior procedure or who had undergone fewer than three prior procedures (P=0.042). Twenty-four of 25 patients (96.0%) who had recurrent pain had a successful operation and five of nine patients (55.6%) who did not have significant relief of pain after the first procedure had a successful operation. The difference was statistically significant (P<0.01). Only four patients had mild complications. CONCLUSION: It is more likely to relieve pain in patients with recurrent or refractory TN who did not have a prior procedure or who had fewer than three procedures before undergoing their first GKRS. Moreover, it seems that patients who had a good response following the initial GKRS had better results after a repeat procedure.

Carotid and transcranial color-coded duplex ultrasonography for the diagnosis of dural arteriovenous fistulas.

BACKGROUND AND PURPOSE: Dural arteriovenous fistulas (DAVF) can affect a variety of cerebral venous structures and can present at various clinical stages. This study was designed to introduce the characteristic manifestation of DAVF detected with both carotid and transcranial color-coded duplex ultrasonography (CDUS) and to evaluate the diagnostic value of CDUS in DAVF. METHODS: Nineteen patients with DAVF confirmed by cerebral angiography were studied with CDUS. The sonogram and spectrum of the affected area were observed. Hemodynamic parameters such as peak systolic velocity, end-diastolic velocity, mean velocity and resistance index (RI) were measured and recorded in the feeding artery, draining vein and extracranial artery. All results were compared with cerebral angiography. Fifty healthy volunteers were enrolled as a control group. Related hemodynamic changes were compared between the patients and normal controls. RESULTS: The blood flow of fistulas presented as an irregular mosaic color bolus with a clear boundary detected with CDUS. Blood flow imaging of fistulas was abnormal in 12 cases and absent in 7 cases. The detection rate was 63% (12/19). Fifty-three main feeding arteries (73.6%) were detected by ultrasonography. All the venous drainages through the transverse sinus and superior ophthalmic vein were detected, while the ones through the superior sagittal sinus and cortical vein were not. There was a significant difference in average diameter, flow velocity and RI of the occipital artery and superficial temporal artery between the patients and normal controls (p < 0.05). CONCLUSIONS: CDUS could indicate DAVF by analyzing both imaging results of the diseased region and hemodynamic changes of the relative vasculature. It is a promising technique for the diagnosis and follow-up study of DAVF.

[Angiographic outcomes of cerebral aneurysms embolized with Matrix coils].

OBJECTIVE: To investigate the effect of Matrix coil in prevention of recanalization of intracranial aneurysm after embolization with Matrix coils. METHODS: Plan of follow-up was designed to make digital subtraction angiographies for Forty-eight intracranial aneurysm patients with 49 aneurysm s, 22 males and 26 females, aged 52 (15 ~ 67), underwent embolization with Matrix coil and were followed up for 11.75 months on average. Digital subtraction angiography was conducted immediately after the operation and during the follow-up. At least three projections, including anterior-posterior projection, lateral projection, and optimal working projection were adopted. The percentages of occlusion of the initial and the follow-up images were compared. RESULTS: DSA immediately after the operation showed a complete occlusion rate of 34.7%, near complete rate of 42.9% and an incomplete rate of 22.4%. The follow-up DSA revealed that the complete occlusion rate was 53.1%, near complete rate was 24.5%, and incomplete rate was 22.4%. The overall recanalization rate was 28.5%, 22.2% for small aneurysms and 46.1% for large aneurysms. The major recanalization rate was 14.3% and the improvement rate was 24.5%. The recanalization rate was 11.8% for total occlusion, 33.3% for near complete occlusion, and 45.5% for incomplete. CONCLUSION: The long-term angiographic outcome of intracranial aneurysms after embolization with Matrix coils is stable. The recanalization rate is acceptable and is not better than that of GDCs.

Transcranial color Doppler flow imaging in detecting severe stenosis of the intracranial vertebral artery: a prospective study.

OBJECTIVE: The aims of this prospective study were to investigate the manifestations of the hemodynamics and morphology of a normal intracranial vertebral artery (VA) and diffusely severe or localized critical vertebral artery stenosis (VAS) on transcranial color Doppler flow imaging (TCDFI) and to discuss the criteria of TCDFI in detecting severe VAS. METHODS: There were 30 patients suspected of having an intracranial VAS in a patient group and 30 healthy volunteers in a control group. All the patients underwent both TCDFI and digital subtraction angiography (DSA). The intracranial VA was imaged through the suboccipital window by TCDFI. The size and tortuousness of the vessels were observed. The hemodynamics of those vessels were measured by means of peak systolic velocity (PSV) and pulsatility index (PI). RESULTS: In the control group, the VA junction with basilar artery appeared as Y shaped and filled with well-distributed blue coded on color imaging, which showed flow below the baseline with fast early systolic acceleration, and normal PSV ranged from 0.42 to 0.80 m/s on pulse wave Doppler. In the patients with diffusely severe VAS (>70% lumen reduction, the length of plaque >1 cm or multiple plaques) or localized critical VAS (>90% lumen reduction) diagnosed by TCDFI and confirmed with DSA, a narrowed and tortuous VA was demonstrated with minimal flow on color Doppler imaging and decreased 50% of normal PSV and PSV <0.30 m/s accompanied by slow early systolic acceleration on Doppler spectrum. There was a significant difference (P<.05 or P<.01) in the hemodynamic parameters (PSV and PI) between patients with severe VAS and healthy subjects. CONCLUSION: TCDFI is a useful noninvasive tool in assessing the hemodynamics of intracranial arteries. The sensitivity was 90.9% and the specificity was 75.0% by using PSV <0.30 m/s and 50% reduction of normal PSV as low cutoff criteria in the diagnosis of diffusely severe or localized critical VAS with TCDFI.

Expression of chimeric antibody in mammalian cells using dicistronic expression vector.

A dicistronic expression vector was constructed for Chinese hamster ovary (CHO) cells that produce both selectable marker-DHFR (dihydrofolate reductase) gene and recombinant antibody cDNA from a single primary transcript via differential splicing. The vector was derived from a pDHL vector and contained the human constant region cDNA so that any human-mouse chimeric antibodies could be expressed. The expression vector produced stable CHO cell clones that secreted nearly double the amount of chimeric antibodies than produced by conventional expression approaches, where the DHFR gene and relevant cDNA are controlled by separate transcription cassettes. Clones with increased expression of interested genes can be efficiently generated by selection in medium containing a gradually increasing amount of methotrexate. The dicistronic expression system using incomplete splicing DHFR gene strategy thus provides a convenient, high-level, and rapid expression of chimeric antibodies.