bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cerebral metabolic correlates as potential predictors of response to anterior cingulotomy for treatment of major depression
Authors: Dougherty Darin D. , Weiss Anthony P. , Cosgrove G. Rees , Alpert Nathaniel M. , Cassem Edwin H. , Nierenberg Andrew A. , Price Bruce H. , Mayberg Helen S. , Fischman Alan J. , Rauch Scott L. 
Published: May 2009

Object. Neurosurgical procedures are a viable intervention for severe, treatment-refractory major depression, although they have been associated with only modest rates of efficacy. The purpose of this study was to identify possible neuroimaging predictors of treatment response to anterior cingulotomy in patients with major depression.
Methods. Thirteen patients underwent stereotactic anterior cingulotomy for treatment-refractory major depression. Symptom severity was measured using the Beck Depression Inventory (BDI) both before and approximately 12 months after surgery. The authors performed [18F]fluorodeoxyglucose—positron emission tomography (PET) studies in all patients preoperatively. Statistical parametric mapping methods were used to test for loci of significant correlation between preoperative regional cerebral metabolism and postoperative reduction in BDI scores.
The mean (± standard deviation) change in the BDI score from the preoperative period (43.7 ± 7.8) to the postoperative period (30.5 ± 21.3) was 33.1 ± 45.4%. Two loci—the left subgenual prefrontal cortex and left thalamus—were identified as sites at which preoperative metabolism was significantly correlated with subsequent improvement in depressive symptom severity following cingulotomy. Specifically, higher preoperative rates of metabolism at these loci were associated with better postoperative results.
Conclusions. Possible PET scanning predictors of treatment response were identified in patients with major depression who had undergone anterior cingulotomy. Further research will be necessary to determine the reproducibility of this finding. If confirmed, the availability of an index for noninvasively predicting a patient's response to cingulotomy for the treatment of major depression would be of great clinical value.
Cerebral oxygenation following decompressive hemicraniectomy for the treatment of refractory intracranial hypertension
Authors: Stiefel Michael F. , Heuer Gregory G. , Smith Michelle J. , Bloom Stephanie , Maloney-Wilensky Eileen , Gracias Vincente H. , Grady M. Sean , Leroux Peter D. 
Published: May 2009

Object.Medically intractable intracranial hypertension is a major cause of morbidity and mortality after severe brain injury. One potential treatment for intracranial hypertension is decompressive hemicraniectomy (DCH). Whether and when to use DCH, however, remain unclear. The authors therefore studied the effects of DCH on cerebral O2to develop a better understanding of the effects of this treatment on the recovery from injury and disease.Methods.The study focused on seven patients (mean age 30.6 ± 9.7 years) admitted to the hospital after traumatic brain injury (five patients) or subarachnoid hemorrhage (two patients) as part of a prospective observational database at a Level I trauma center. At admission the Glasgow Coma Scale (GCS) score was 6 or less in all patients. Patients received continuous monitoring of intracranial pressure (ICP), cerebral perfusion pressure (CPP), blood pressure, and arterial O2saturation. Cerebral oxygenation was measured using the commercially available Licox Brain Tissue Oxygen Monitoring System manufactured by Integra NeuroSciences. A DCH was performed when the patient's ICP remained elevated despite maximal medical management.Conclusions.All patients tolerated DCH without complications. Before the operation, the mean ICP was elevated in all patients (26 ± 4 mm Hg), despite maximal medical management. After surgery, there was an immediate and sustained decrease in ICP (19 ± 11 mm Hg) and an increase in CPP (81 ± 17 mm Hg). Following DCH, cerebral oxygenation improved from a mean of 21.2 ± 13.8 mm Hg to 45.5 ± 25.4 mm Hg, a 114.8% increase. The change in brain tissue O2and the change in ICP after DCH demonstrated only a modest relationship (r2= 0.3). These results indicate that the use of DCH in the treatment of severe brain injury is associated with a significant improvement in brain O2.
Reduction of neural adhesions by biodegradable autocrosslinked hyaluronic acid gel after injury of peripheral nerves: an experimental study
Authors: Smit Xander , van Neck Johan W. , Afoke Andrew , Hovius Steven E. R. 
Published: May 2009

Object. Adhesion formation is a serious problem in peripheral nerve surgery, frequently causing dysfunction and pain. The authors aimed to develop an objective biomechanical method of quantifying nerve adhesions and to use this technique for the evaluation of the efficacy of an autocrosslinked hyaluronic acid (HA) gel as an antiadhesion therapy.
Methods. Thirty-three female Wistar rats underwent dissection, crush injury, or transection plus repair of the sciatic nerve. The nerves were or were not treated with the HA gel. Six weeks after surgery, the adhesions formed were assessed by measuring the peak force required to break the adhesions over a standardized area. Results of biomechanical measurements demonstrated that the peak force significantly increased as the severity of the injury increased. After using the HA gel to treat the nerve, the peak force was significantly reduced in rats with any of the three types of injuries; peak force decreased by 26% in the animals in the dissection group, 29% in the crush injury group, and 38% in the transection and repair group, compared with the untreated animals.
Conclusions. The biomechanical method described is an objective, quantitative technique for the assessment of nerve adherence to surrounding tissue. It will be a valuable tool in future studies on antiadhesion therapies. Furthermore, HA gel significantly reduces nerve adhesions after different types of nerve injuries.
Isolation of immortalized, INK4a/ARF-deficient cells from the subventricular zone after in utero N-ethyl-N-nitrosourea exposure
Authors: Savarese Todd M. , Jang Taichang , Pang Low Hoi , Salmonsen Rebecca , Litofsky N. Scott , Matijasevic Zdenka , Ross Alonzo H. , Recht Lawrence D. 
Published: May 2009

Object. Brain tumors, including gliomas, develop several months after rats are exposed in utero to N-ethyl-N-nitrosourea (ENU). Although pathological changes cannot be detected until these animals are several weeks old, the process that eventually leads to glioma formation must begin soon after exposure given the rapid clearance of the carcinogen and the observation that transformation of brain cells isolated soon after exposure occasionally occurs. This model can therefore potentially provide useful insights about the early events that precede overt glioma formation. The authors hypothesized that future glioma cells arise from stem/progenitor cells residing in or near the subventricular zone (SVZ) of the brain.
Methods. Cells obtained from the SVZ or corpus striatum in ENU-exposed and control rats were cultured in an epidermal growth factor (EGF)-containing, chemically defined medium. Usually, rat SVZ cells cultured in this manner (neurospheres) are nestin-positive, undifferentiated, and EGF-dependent and undergo cell senescence. Consistent with these prior observations, control SVZ cells undergo senescence by the 12th to 15th doubling (20 of 20 cultures). In contrast, three of 15 cultures of cells derived from the SVZs of individual ENU-treated rats continue to proliferate for more than 60 cell passages. Each of these nestin-expressing immortalized cell lines harbored a common homozygous deletion spanning the INK4a/ARF locus and was unable to differentiate into neural lineages after exposure to specific in vitro stimuli. Nevertheless, unlike the rat C6 glioma cell line, these immortalized cell lines demonstrate EGF dependence and low clonogenicity in soft agar and did not form tumors after intracranial transplantation.
Conclusions. Data in this study indicated that immortalized cells may represent glioma precursors that reside in the area of the SVZ after ENU exposure that may serve as a reservoir for further genetic and epigenetic hits that could eventually result in a full glioma phenotype.
Limited efficacy of gene transfer in herpes simplex virus-thymidine kinase/ganciclovir gene therapy for brain tumors
Authors: Hadaczek Piotr , Mirek Hanna , Berger Mitchel S. , Bankiewicz Krystof 
Published: May 2009

Object. Low efficacy of gene transfer, transient gene expression, and toxicity of viral vectors are the major hurdles in successful anticancer gene therapy. The authors conducted in vitro (U87MG cell line) and in vivo (xenograft, tumor-bearing rodent model) studies to address the stability of transduction by using the adenoassociated virus serotype-2 (AAV2)—thymidine kinase (TK) vector over time.
Methods. Standard methods for cell growth and a ganciclovir (GCV) cytotoxicity assay were applied. The AAV2-TK was infused into implanted tumors in athymic rats via convection-enhanced delivery (CED). Thymidine kinase expression was evaluated through immunohistochemical analysis, and the distribution volumes of the transduced tumors were calculated. Twenty-four hours following the viral infusions, animals were treated with GCV (50 mg/kg intraperitoneally every day for 10 days; six rats) or phosphate-buffered saline (six rats).
A rapid decrease in TK expression over time was observed both in vitro and in vivo. A large volume of the tumor (up to 39%) was transduced with AAV2-TK following CED. Administration of GCV resulted in limited therapeutic effects (survival of 25.8 compared with 21.3 days).
Conclusions. Rapid elimination of TK expression from dividing tumor cells and focal transduction of the brain tumor were most likely responsible for the limited bystander effect in this approach. Immediate administration of GCV is crucial to assure maximal efficacy in the elimination of cancer cells. In addition, the complete or diffused transduction of a brain tumor with TK may be required for its total eradication.
Does new magnetic resonance imaging technology provide better geometrical accuracy during stereotactic imaging?
Authors: Novotny Josef , Vymazal Josef , Novotny Josef , Tlachacova Daniela , Schmitt Michal , Chuda Pavel , Urgosik Dusan , Liscak Roman 
Published: May 2009

Object.The authors sought to compare the accuracy of stereotactic target imaging using the Siemens 1T EXPERT and 1.5T SYMPHONY magnetic resonance (MR) units.Methods.A water-filled cylindrical Perspex phantom with axial and coronal inserts containing grids of glass rods was fixed in the Leksell stereotactic frame and subjected to MR imaging in Siemens 1T EXPERT and Siemens 1.5T SYMPHONY units. Identical sequences were used for each unit. The images were transferred to the GammaPlan treatment planning system. Deviations between stereotactic coordinates based on MR images and estimated real geometrical positions given by the construction of the phantom insert were evaluated for each study. The deviations were further investigated as a function of the MR unit used, MR sequence, the image orientation, and the spatial position of measured points in the investigated volume.Conclusions.Larger distortions were observed when using the SYMPHONY 1.5T unit than those with the EXPERT 1T unit. Typical average distortion in EXPERT 1T was not more than 0.6 mm and 0.9 mm for axial and coronal images, respectively. Typical mean distortion for SYMPHONY 1.5T was not more than 1 mm and 1.3 mm for axial and coronal images, respectively. The image sequence affected the distortions in both units. Coronal T2-weighted spin-echo images performed in subthalamic imaging produced the largest distortions of 2.6 mm and 3 mm in the EXPERT 1T and SYMPHONY 1.5T, respectively. Larger distortions were observed in coronal slices than in axial slices in both units, and this effect was more pronounced in SYMPHONY 1.5T. Noncentrally located slice positions in the investigated volume of the phantom were associated with larger distortions.
Late cyst formation following gamma knife surgery of arteriovenous malformations
Authors: Pan Hung-Chuan , Sheehan Jason , Stroila Matei , Steiner Melita , Steiner Ladislau 
Published: May 2009

Object.The authors present data concerning the development of cysts following gamma knife surgery (GKS) in 1203 consecutive patients with arteriovenous malformations (AVMs) treated by the senior author (L.S.). The cyst was defined as a fluid-filled cavity at the site of a treated AVM. Cases involving regions corresponding to previous hematoma cavities were excluded. The incidence of cyst formation was assessed using magnetic resonance imaging studies performed in 196 cases with more than 10 years of follow up, in 332 cases with 5 to 10 years of follow up, and in 675 cases with less than 5 years of follow up. One hundred five cases were lost to follow-up study. The Cox regression method was used to analyze the factors related to cyst formation.Methods.The incidence of cyst formation in the entire patient population was 1.6 and 3.6% in those undergoing follow-up examination for more than 5 years. Ten of 20 cysts developed between 10 to 23 years, nine between 5 to 10 years, and one in less than 5 years following the treatment. Cyst fluid aspiration, cystoperitoneal shunt placement, or craniotomy were used in three symptomatic cases. Analysis of age, sex, and treatment parameters yielded no significant relationship with cyst formation; however, radiation-induced tissue change following GKS (p = 0.027) and prior embolization (p = 0.011) were related to cyst formation.Conclusions.Overall, the incidence of cyst formation in patients who underwent GKS for AVM was 1.6%. The development of the cyst was related to the duration of the follow-up period. When cysts are symptomatic, surgical intervention should be performed.
Power Doppler imaging in detection of surgically induced indirect neoangiogenesis in adult moyamoya disease
Authors: Perren Fabienne , Horn Peter , Vajkoczy Peter , Schmiedek Peter , Meairs Stephen 
Published: May 2009

Object. Moyamoya is a rare, chronic disease that leads to the progressive narrowing and/or occlusion of the distal internal carotid and proximal cerebral arteries. Chronic cerebral ischemia ensues due to insufficient collateral blood supply. One potential treatment consists of the restoration of regional cerebral blood flow by direct or indirect revascularization surgery. The extent of neovascularization, especially in indirect procedures such as encephalomyosynangiosis (EMS), is currently evaluated with conventional angiography. Because this method is invasive and carries some risks, the authors investigated power Doppler imaging as an alternative noninvasive bedside procedure that can be used to assess surgically induced indirect revascularization in adult patients with moyamoya disease.
Methods. Twelve symptomatic patients with adult moyamoya disease (seven women and five men, mean age 38 ± 17 years) underwent combined (direct and indirect) revascularization. They were then examined using conventional angiography and power Doppler imaging to assess the extent of revascularization within 120 days postsurgery. According to the number of intracranial vessels demonstrating opacification on conventional angiography and power Doppler imaging studies, EMS was graded as follows: 1, absent (0 vessels); 2, moderate (one—four vessels); and 3, extensive (> four vessels) for both methods. Examiners were blinded to the classification results for the procedure that they did not grade.
All 24 hemispheres were examined. The visual grading of EMS revealed a highly significant agreement between conventional angiography and power Doppler imaging (Spearman rank coefficient, r = 0.92; p < 0.001) and there was 100% agreement of patency of the bypass between the direct and indirect methods.
Conclusions. The authors found excellent agreement between the two methods. Therefore, power Doppler imaging is a valid noninvasive alternative to carotid artery angiography in evaluating direct and indirect revascularization.
Flow changes caused by the sequential placement of stents across the neck of sidewall cerebral aneurysms
Authors: Cantón Gádor , Levy David I. , Lasheras Juan C. , Nelson Peter K. 
Published: May 2009

Object. The goal of this study was to quantify the reduction in velocity, vorticity, and shear stresses resulting from the sequential placement of stents across the neck of sidewall cerebral aneurysms.
Methods. A digital particle image velocimetry (DPIV) system was used to measure the pulsatile velocity field within a flexible silicone sidewall intracranial aneurysm model and at the aneurysm neck–parent artery interface in this model. The DPIV system is capable of providing an instantaneous, quantitative two-dimensional measurement of the velocity vector field of “blood” flow inside the aneurysm pouch and the parent vessel, and its changes at varying stages of the cardiac cycle. The corresponding vorticity and shear stress fields are then computed from the velocity field data. Three Neuroform stents (Boston Scientific/Target), each with a strut thickness between 60 and 65 µm, were subsequently placed across the neck of the aneurysm model and measurements were obtained after each stent had been placed.
The authors measured a consistent decrease in the values of the maximal averaged velocity, vorticity, and shear stress after placing one, two, and three stents. Measurements of the circulation inside the sac demonstrated a systematic reduction in the strength of the vortex due to the stent placement. The decrease in the magnitude of the aforementioned quantities after the first stent was placed was remarkable. Placement of two or three stents led to a less significant reduction than placement of the first stent.
Conclusions. The use of multiple flexible intravascular stents effectively reduces the strength of the vortex forming in an aneurysm sac and results in a decrease in the magnitude of stresses acting on the aneurysm wall.
Nerve regeneration across a 2-cm gap in the rat median nerve using a resorbable nerve conduit filled with Schwann cells
Authors: Sinis Nektarios , Schaller Hans-Eberhard , Schulte-Eversum Caterina , Schlosshauer Burkhard , Doser Michael , Dietz Klaus , Rösner Harald , Müller Hans-Werner , Haerle Max 
Published: May 2009

Object. In a rat model, nerve regeneration was evaluated across a 2-cm defect in the median nerve by using a resorbable artificial nerve conduit. The aim of this study was to develop an artificial, biocompatible nerve guide to induce regeneration in the peripheral nervous system.
Methods. The authors compared a nerve conduit of trimethylenecarbonate-co-epsilon-caprolactone (TMC/CL) filled with autologous Schwann cells with both an empty hollow conduit and an autologous nerve graft. Animals that did not undergo surgery served as the control group. Nerve regeneration was evaluated with the grasping test, histological analysis of the nerve, muscle weight analysis (flexor digitorum superficialis muscle), and electrophysiological examination.
After an observation period of 9 months, regeneration occurred only in animals that had received an autologous graft or a Schwann cell containing nerve conduit. No signs of regeneration were found in animals supplied with the empty conduit.
Conclusions. Results of this study reveal the important role of Schwann cells in the regeneration process across a 2-cm defect in the rat median nerve. Furthermore, Schwann cell—filled nerve conduits induced functional recovery, as demonstrated in the grasping test, that was comparable with that of the autologous graft 9 months after implantation.
Effects of positive reinforcement training techniques on the psychological welfare of zoo‐housed chimpanzees (Pan troglodytes)
Authors: Pomerantz Ori , Terkel Joseph 
Published: May 2009

AbstractCaptive environments encompass various factors that can elevate stress levels and jeopardize the wellbeing of the captive animals. The use of positive reinforcement training (PRT) techniques enables researchers and caretakers to reduce tension directly associated with potentially stressful procedures and states. The current study tested the general effect of PRT on the wellbeing of zoo‐housed chimpanzees (Pan troglodytes) by measuring behaviors that reflect poor and good welfare and that were not directly connected to the specific aim of the training session. The behavior of a group of twelve chimpanzees was measured throughout the day from the exhibition yard, at baseline (12 weeks) and during the PRT period (10 weeks). The results show a significant decrease in abnormal and stress‐related behaviors and a significant rise in prosocial affiliative behaviors following implementation of the training program. The training was shown to have a greater positive effect on low‐ranking individuals compared with high‐ranking ones. This research shows for the first time that PRT offers an enrichment effect whose general influence lasts throughout the day, irrespective of any direct link to a specific trained behavior. Consequently, it can be claimed that PRT presents an effective enrichment tool that can be implemented with captive animals. Because of the above‐noted differential effect between high‐ and low‐ranking chimpanzees, however, this should be taken into consideration when combining PRT with the non‐human primates' daily routine. Am. J. Primatol. 71:687–695, 2009. © 2009 Wiley‐Liss, Inc.
A ‘sea change’ for collective bargaining as the U.S. Supreme Court permits unions to agree to arbitration for discrimination claims
Authors: Walsh Christopher 
Published: May 2009

AbstractLast month's U.S. Supreme Court decision in 14 Penn Plaza LLC v. Pyett may signal a big change in the skills needed by labor arbitrators, according to Christopher Walsh, of Newark, N.J. He analyzes the case and tells readers what to expect as a result of Justice Clarence Thomas's majority opinion.
Ventricular dilation: Association with gait and cognition
Authors: Palm Walter M. , Saczynski Jane S. , van der Grond J. , Sigurdsson Sigurdur , Kjartansson Olafur , Jonsson Palmi V. , Eiriksdottir Gudny , Gudnason Vilmundur , Admiraal‐Behloul Faiza , Launer Lenore J. , van Buchem Mark A. ,   Age, Gene/Environment Susceptibility–Reykjavik Study
Published: May 2009

AbstractObjectiveNormal pressure hydrocephalus is characterized by gait impairment, cognitive impairment, and urinary incontinence, and is associated with disproportionate ventricular dilation. Here we report the distribution of ventricular volume relative to sulcal cerebrospinal fluid (CSF) volume, and the association of increasing ventricular volume relative to sulcal CSF volume with a cluster of gait impairment, cognitive impairment, and urinary incontinence in a stroke‐free cohort of elderly persons from the general population.MethodsData are based on 858 persons (35.4% men; age range, 66–92 years) who participated in the Age, Gene/Environment Susceptibility–Reykjavik Study. Gait was evaluated with an assessment of gait speed. Composite scores representing speed of processing, memory, and executive function were constructed from a neuropsychological battery. Bladder function was assessed with a questionnaire. Magnetic resonance brain imaging was followed by semiautomated segmentation of intracranial CSF volume. White matter hyperintensity (WMH) volume was assessed with a semiquantitative scale. For the analysis of ventricular dilation relative to the sulcal spaces, ventricular volume was divided by sulcal CSF volume (VV/SV).ResultsDisproportion between ventricular and sulcal CSF volume, defined as the highest quartile of the VV/SV z score, was associated with gait impairment (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.1–3.3) and cognitive impairment (OR, 1.8; 95% CI, 1.1–3.0). We did not find an association between the VV/SV z score and bladder dysfunction.InterpretationThe prevalence and severity of gait impairment and cognitive impairment increases with ventricular dilation in persons without stroke from the general population, independent of WMH volume. Ann Neurol 2009;66:485–493