bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evidence for telomerase involvement in the angiogenesis of astrocytic tumors: expression of human telomerase reverse transcriptase messenger RNA by vascular endothelial cells
Authors: Pallini Roberto , Pierconti Francesco , Falchetti Maria Laura , D'Arcangelo Daniela , Fernandez Eduardo , Maira Giulio , D'Ambrosio Ettore , Larocca Luigi Maria 
Published: May 2009

Object. Evidence from recent in vitro studies indicates that reactivation of telomerase, the enzyme that synthesizes the telomere ends of chromosomes, is a crucial event in the unlimited clonal expansion of endothelial cells that precedes the neoplastic conversion of these cells. It is known that high-grade gliomas express telomerase and that, in these neoplasms, proliferating endothelial cells may undergo transformational changes with development of sarcomatous components within the primitive tumor. To assess whether telomerase is involved in the endothelial cell proliferation that characterizes brain tumor angiogenesis, the authors investigated at the single-cell level the expression of messenger (m)RNA for the human telomerase catalytic subunit human telomerase reverse transcriptase (hTERT) by vascular cells of astrocytic tumors.
Methods. The in situ hybridization (ISH) method was performed by processing histological sections with specific riboprobes for hTERT and for c-myc, an oncogene that is known to upregulate hTERT. Results of the ISH studies were compared with proliferative activity, as estimated by Ki-67 immunostaining. The expression of hTERT mRNA by vascular endothelial cells was related to the histological grade of the tumor because it was detected in five (29%) of 17 low-grade astrocytomas, nine (56%) of 16 anaplastic astrocytomas, and 19 (100%) of 19 glioblastomas multiforme (GBMs). Expression of c-myc mRNA was strictly correlated with that of hTERT mRNA. In low-grade astrocytomas and anaplastic astrocytomas, a dissociation was noted between hTERT mRNA expression and the proliferation rate of endothelial cells. Conversely, GBMs displayed a significant correlation between the level of hTERT mRNA expression and endothelial cell proliferation. Data from an in vitro assay in which human umbilical vein endothelial cells were stimulated to proliferate by adding vascular endothelial growth factor and an ISH study of newly formed vessels surrounding brain infarcts confirmed that expression of hTERT mRNA does not merely reflect the proliferative status of endothelial cells but represents a specific feature of brain tumor neovascularization.
Conclusions. The results of this study are consistent with a role of telomerase in the angiogenesis of astrocytic tumors. Expression of hTERT mRNA by tumor vascular cells is an early event during the progression of astrocytic tumors, which precedes endothelial cell proliferation and may represent a first sign of dedifferentiation. Other than elucidating the mechanisms of tumor angiogenesis, these results encourage research on antitelomerase drugs for the treatment of malignant gliomas.
Molecular determinants of glioma cell migration and invasion
Authors: Wild-Bode Christine , Weller Michael , Wick Wolfgang 
Published: May 2009

Object. Migration and invasion are important prerequisites for the infiltrative and destructive growth patterns of malignant gliomas. Infiltrative growth prevents complete tumor resection and causes significant neurological morbidity and mortality.
Methods. The authors assessed the expression of matrix metalloproteinases (MMPs) at messenger RNA and protein levels, MMP-2 and MMP-9 activities, and expression levels of a panel of anti- and proapoptotic proteins of the BCL-2 family. They then correlated their findings with αVβ3 integrin expression and the migratory and invasive potentials in 12 human malignant glioma cell lines.
Multiple MMPs were expressed by most cell lines. The levels of MMP-2 and MMP-3 and the activities of MMP-2 and MMP-9 correlated with tumor cell invasion. Migration and invasion were also correlated. Although the expression levels of αVβ3 integrin did not predict migration or invasion, a neutralizing αVβ3 integrin antibody inhibited migration and invasion selectively in cell lines that contained a high level of αVβ3 integrin expression, thus indicating the important role of αVβ3 integrin for migration and invasion in this subset of cell lines. An expression pattern of BCL-2 family proteins that favor resistance to apoptosis was associated with enhanced migration, invasion, and MMP activity. Wild-type p53 cell lines migrated farther than mutant p53 cell lines.
Conclusions. Activities of MMP-2 and MMP-9 are the best predictors of glioma cell invasion. The αVβ3 integrin mediates migration and invasion in a subset of glioma cell lines, but these processes do not depend on αVβ3 integrin expression. Antiapoptotic BCL-2 family protein expression is a predictor of efficient migration and invasion.
Sagittal suture as an external landmark for the superior sagittal sinus
Authors: Tubbs R. Shane , Salter George , Elton Scott , Grabb Paul A. , Oakes W. Jerry 
Published: May 2009

Object. Historically, the sagittal suture has been used as an external landmark to indicate the middle portion of the superior sagittal sinus (SSS). The goal of this study was to verify this relationship.
Methods. The authors examined 30 adult cadavers to reveal the location of the SSS with respect to the sagittal suture. Their findings demonstrated that the SSS is deviated to the right of the sagittal suture in the majority of observed specimens, although the maximum displacement to the right side was never more than 11 mm.
Conclusions. This information should be useful to the neurosurgeon who must be aware of the SSS and its relationship with superficial skull landmarks.
Serum cortisol response to transsphenoidal surgery for Cushing disease
Authors: Simmons Nathan E. , Alden Tord D. , Thorner Michael O. , Laws Edward R. 
Published: May 2009

Object. Transsphenoidal surgery remains the optimal treatment for Cushing disease, but the definitions of surgical cure and failure remain debatable. In this study the authors evaluated serum cortisol levels in patients before and after they underwent transsphenoidal surgery to elucidate the patterns of cortisol decrease and the optimal time and criteria for determining surgically induced remission.
Methods. Twenty-seven patients were evaluated throughout an 8-month period. Serum cortisol levels were obtained before surgery and at 6-hour intervals postoperatively. No exogenous steroid medications were administered until after cortisol sampling was discontinued, following diagnosis of remission.
Twenty-one (78%) of 27 cases were labeled initial surgically induced remissions. Twenty-two (81%) of 27 cases were deemed surgically induced remissions at follow-up examination. Following surgery, initial remissions and failures demonstrated divergent patterns of cortisol levels. No patient whose condition was deemed an initial surgically induced remission has experienced definitive relapse of disease since discharge. One patient whose condition was initially deemed a surgical failure, eventually was found to exhibit surgically induced remission without further intervention.
Conclusions. Given such findings, exogenous steroid medications do not appear to be required for patients until after the determination of remission. During the 1st postoperative day, there is a time period during which serum cortisol values significantly differ between the categories of surgically induced remissions and surgical failures. Surgically induced remissions were identified when postoperative values of cortisol were lower than preoperative midnight levels and when absolute values of cortisol were less than 10 µg/dl. In a small proportion of patients remission on a delayed basis may also be demonstrated. These data allow for a simple and rapid determination of postoperative remission in patients undergoing transsphenoidal surgery for Cushing disease.
Identification of novel regions of allelic loss in ependymomas by high-resolution allelotyping with 384 microsatellite markers
Authors: Tong Carol Yuen-kwan , Zheng Ping-pin , Pang Jesse Chung-sean , Poon Wai-sang , Chang Alexander R. , Ng Ho-keung 
Published: May 2009

Object. Ependymomas are rare glial neoplasms; little is known about the molecular pathogenesis of this tumor entity. In a previous study the authors found multiple genomic imbalances in ependymomas resected in 20 adults and eight children, including loss of chromosomes 1p, 6, 16, 17, 19q, 20q, and 22q, as well as gain of chromosomes 4q, 5q, 7q, 9q, and 12q on comparative genomic hybridization. The aim of this study was to map in more detail the commonly affected regions in ependymomas.
Methods. A comprehensive allelotype analysis of 16 ependymomas was conducted using 384 microsatellite markers that span the 22 autosomes. Based on this high-resolution loss of heterozygosity analysis, multiple overlapping deletion regions were identified as follows: 6q25.2–27, 16p12–13.1, 16q22.3–24.1, 17q22–24, 19q12–13.2, 20q13.2–13.3, and 22q13.1–13.3.
Conclusions. These data confirmed previous reports that loss of chromosomes 17 and 22 were common in ependymomas. Moreover, the authors were able to identify loss of chromosomes 13, 16, 19, and 20 as novel findings in ependymomas. It is believed that potential tumor suppressor genes that reside in these commonly deleted regions may contribute to the molecular tumorigenesis of ependymomas.
Combined surgical and endovascular techniques of flow alteration to treat fusiform and complex wide-necked intracranial aneurysms that are unsuitable for clipping or coil embolization
Authors: Hoh Brian L. , Putman Christopher M. , Budzik Ronald F. , Carter Bob S. , Ogilvy Christopher S. 
Published: May 2009

Object. Certain intracranial aneurysms, because of their fusiform or complex wide-necked structure, giant size, or involvement with critical perforating or branch vessels, are unamenable to direct surgical clipping or endovascular coil treatment. Management of such lesions requires alternative or novel treatment strategies. Proximal and distal occlusion (trapping) is the most effective strategy. In lesions that cannot be trapped, alteration in blood flow to the “inflow zone,” the site most vulnerable to aneurysm growth and rupture, is used.
Methods. From 1991 to 1999 the combined neurosurgical—neuroendovascular team at the Massachusetts General Hospital (MGH) managed 48 intracranial aneurysms that could not be clipped or occluded. Intracavernous internal carotid artery aneurysms were excluded from this analysis. By applying a previously described aneurysm rupture risk classification system (MGH Grades 0–5) based on the age of the patient, aneurysm size, Hunt and Hess grade, Fisher grade, and whether the aneurysm was a giant lesion located in the posterior circulation, the authors found that a significant number of patients were at moderate risk (MGH Grade 2; 31.3% of patients) and at high risk (MGH Grades 3 or 4; 22.9%) for treatment-related morbidity. The lesions were treated using a variety of strategies—surgical, endovascular, or a combination of modalities. Aneurysms that could not be trapped or occluded were treated using a paradigm of flow alteration, with flow redirected from either native collateral networks or from a surgically performed vascular bypass. Overall clinical outcomes were determined using the Glasgow Outcome Scale (GOS). A GOS score of 5 or 4 was achieved in 77.1%, a GOS score of 3 or 2 in 8.3%, and death (GOS 1) occurred in 14.6% of the patients. Procedure-related complications occurred in 27.1% of cases; the major morbidity rate was 6.3% and the mortality rate was 10.4%. Three patients experienced aneurysmal hemorrhage posttreatment; in two patients this event proved to be fatal. Aneurysms with MGH Grades 0, 1, 2, 3, and 4 were associated with favorable outcomes (GOS scores of 5 or 4) in 100%, 92.8%, 71.4%, 50%, and 0% of instances, respectively.
Conclusions. Despite a high incidence of transient complications, intracranial aneurysms that cannot be clipped or occluded require alternative surgical and endovascular treatment strategies. In those aneurysms that cannot safely be trapped or occluded, one approach is the treatment strategy of flow alteration.
Efficacy of controlled-release papaverine pellets in preventing symptomatic cerebral vasospasm
Authors: Dalbasti Tayfun , Karabiyikoglu Murat , Ozdamar Nurcan , Oktar Nezih , Cagli Sedat 
Published: May 2009

Object. Vasospasm as a complication of subarachnoid hemorrhage is a major concern in clinical practice. The systemic drugs in current use are of limited value. Topical, intrathecal, or intraarterial papaverine administered during surgical or angiographic procedures is a potent vasodilating drug; however, hypotension limits its systemic application. Local application of papaverine in a biodegradable controlled- or sustained-release matrix is proposed for vasospasm prophylaxis to be used in patients scheduled for aneurysm surgery.
Methods. Controlled-release papaverine (PapaCR) drug pellets were prepared using the biodegradable aliphatic polyester poly(DL-lactide-co-glycolide) as the carrier matrix. In vitro tests were performed to determine drug kinetics. One hundred seventeen patients, 73 assigned to the control group and 44 assigned to the PapaCR-treated group, participated in this study. Patients who were deemed to be at high risk for the development of vasospasm were selected to participate in the study. During aneurysm surgery, drug pellets were placed in cisterns over arterial segments. In two patients, cerebrospinal fluid was sampled every 6 hours for the first 5 days through a lumbar catheter that had been inserted at the beginning of aneurysm surgery. The incidence of clinical vasospasm and Glasgow Outcome Scale scores in the patients were evaluated statistically.
The results of in vitro studies showed that effective local concentrations of papaverine could be maintained for more than 10 days. The first-degree drug-release profile was demonstrated using this design. In clinical studies no adverse effects due to the drug were seen. The PapaCR effectively prevented development of clinical vasospasm, and outcome scores were significantly better in patients in the treated group.
Conclusions. Local application of controlled- or sustained-release papaverine can be safely used in preventing vasospasm.
Sensory ganglionectomy: theory, technical aspects, and clinical experience
Authors: Wilkinson Harold A. , Chan Andy S. 
Published: May 2009

Object. Sensory ganglionectomy offers theoretical advantages over rhizotomy but remains controversial because reported success rates vary widely. The authors sought to add to the available data on this subject and to review technical aspects of the surgery.
Methods. This retrospective chart review included 19 patients, in whom 22 operations were performed and 35 sensory ganglia were resected between May 1995 and May 1999. The eight women and 11 men ranged in age from 27 to 75 years (median age 40 years, average age 42.3 years). All patients had undergone extensive therapy and a mean of 2.4 previous operations (median three, range zero—eight operations) for their pain, all without long-term pain relief. Duration of symptoms varied, from 1 month (for the cancer patient) to 15 years (mean 5.9, median 4 years). Preoperatively, all patients underwent diagnostic selective nerve root blocks, which temporarily relieved their targeted pain. The duration of follow up averaged 22 months (median 13, range 1.5 [to death of the cancer patient]—58 months). Before undergoing the first ganglionectomy, nearly all patients rated their targeted pain as 8 to 10 (average 9.6, median 10) on an analog (0–10) pain scale.
At 6 months all patients rated their ganglionectomy-specific pain as an average of 4.5 (median 4, range 0–8), and pain reduction of 50% or more was achieved in 74%. At 1 year or more the 13 patients available for study rated their pain as an average of 4.3 (median 4.5, range 0–9). There were no severe complications, residual pain was never worse than presurgical pain, and no patient experienced significant or lasting new motor deficits.
Conclusions. Dorsal root ganglionectomy has a useful role in the treatment of a variety of refractory pain states, especially those involving radicular pain.
Reliability of intraoperative electrophysiological monitoring in selective posterior rhizotomy
Authors: Mittal Sandeep , Farmer Jean-Pierre , Poulin Chantal , Silver Kenneth 
Published: May 2009

Object. Selective posterior rhizotomy is a well-established treatment for spasticity associated with cerebral palsy. At most medical centers, responses of dorsal rootlets to electrical stimulation are used to determine ablation sites; however, there has been some controversy regarding the reliability of intraoperative stimulation. The authors analyzed data obtained from the McGill Rhizotomy Database to determine whether motor responses to dorsal root stimulation were reproducible.
Methods. A series of 77 patients underwent selective dorsal rhizotomy at a single medical center. The dorsal roots from L-2 to S-2 were stimulated to determine the threshold amplitude. The roots were then stimulated at 2 to 4 times the highest threshold with a 1-second 50-Hz train. A second stimulation run of the entire dorsal root was performed before it was divided into rootlets. Rootlets were individually stimulated and sectioned according to the extent of abnormal electrophysiological propagation. Motor responses were recorded by electromyography and were also assessed by a physiotherapist, and grades of 0 to 4+ were assigned. The difference in grades between the first and second stimulation trains was determined for 752 roots.
Statistical analysis demonstrated a clear consistency in motor responses between the two stimulation runs, both in the electromyographic readings and the physiotherapist's assessment. More than 93% of dorsal roots had either no change or a difference of only one grade between the two trials. Furthermore, the vast majority of dorsal roots assigned a grade of 4+ at the first trial maintained the same maximally abnormal electrophysiological response during the second stimulation run.
Conclusions. This study indicates that currently used techniques are reproducible and reliable for selection of abnormal rootlets. Intraoperative electrophysiological stimulation can be valuable in achieving a balance between elimination of spasticity and preservation of underlying strength.
Obstructive hydrocephalus caused by intraventricular collapse of malacotic brain
Authors: Nakaguchi Hiroshi , Miyamoto Mario 
Published: May 2009

✓ The authors present the case of a 68-year-old man who experienced acute obstructive hydrocephalus after having suffered an infarction in the occipital lobe. Histopathological and serial neuroimaging examinations revealed that portions of a large disintegrating occipital infarct had entered the lateral ventricle and obstructed the passage of cerebrospinal fluid (CSF). Ventricular drainage was performed for 2 weeks until the patient's hydrocephalus resolved. The CSF initially contained a high concentration of protein (1070 mg/dl), a high leukocyte count of 115 cells/mm3, and a rich fibrinous exudate.
Findings in the present case indicate that collapse of a periventricular ischemic lesion into the ventricles may sometimes occur not only after cerebral hemorrhage but also after cerebral infarction.
A multivariate analysis of 416 patients with glioblastoma multiforme: prognosis, extent of resection, and survival
Authors: Lacroix Michel , Abi-Said Dima , Fourney Daryl R. , Gokaslan Ziya L. , Shi Weiming , DeMonte Franco , Lang Frederick F. , McCutcheon Ian E. , Hassenbusch Samuel J. , Holland Eric , Hess Kenneth , Michael Christopher , Miller Daniel , Sawaya Raymond 
Published: May 2009

Object. The extent of tumor resection that should be undertaken in patients with glioblastoma multiforme (GBM) remains controversial. The purpose of this study was to identify significant independent predictors of survival in these patients and to determine whether the extent of resection was associated with increased survival time.
Methods. The authors retrospectively analyzed 416 consecutive patients with histologically proven GBM who underwent tumor resection at the authors' institution between June 1993 and June 1999. Volumetric data and other tumor characteristics identified on magnetic resonance (MR) imaging were collected prospectively.
Conclusions. Five independent predictors of survival were identified: age, Karnofsky Performance Scale (KPS) score, extent of resection, and the degree of necrosis and enhancement on preoperative MR imaging studies. A significant survival advantage was associated with resection of 98% or more of the tumor volume (median survival 13 months, 95% confidence interval [CI] 11.4–14.6 months), compared with 8.8 months (95% CI 7.4–10.2 months; p < 0.0001) for resections of less than 98%. Using an outcome scale ranging from 0 to 5 based on age, KPS score, and tumor necrosis on MR imaging, we observed significantly longer survival in patients with lower scores (1–3) who underwent aggressive resections, and a trend toward slightly longer survival was found in patients with higher scores (4–5). Gross-total tumor resection is associated with longer survival in patients with GBM, especially when other predictive variables are favorable.
Long-term outcome after gamma knife surgery for secondary trigeminal neuralgia
Authors: Régis Jean , Metellus Philippe , Dufour Henry , Roche Pierre-Hughes , Muracciole Xavier , Pellet William , Grisoli Francois , Peragut Jean-Claude 
Published: May 2009

Object. This study was directed to evaluate the potential role of gamma knife surgery (GKS) in the treatment of secondary trigeminal neuralgia (TN). The authors have identified three anatomicoclinical types of secondary TN requiring different radiosurgical approaches.
Methods. Pain control was retrospectively analyzed in a population of patients harboring tumors of the middle or posterior fossa that involved the trigeminal nerve pathway. This series included 53 patients (39 women and 14 men) treated using GKS between July 1992 and June 1997. The median follow-up period was 55 months. Treatment strategies differed according to lesion type, topography, and size, as well as visibility of the fifth cranial nerve in the prepontine cistern. Three different treatment groups were established. When the primary goal was treatment of the lesion (Group IV, 46 patients) we obtained pain cessation in 79.5% of cases. In some patients in whom GKS was not indicated for treatment of the lesion, TN was treated by targeting the fifth nerve directly in the prepontine cistern if visible (Group II, three patients) or in the part of the lesion including this nerve if the nerve root could not be identified (Group III, four patients). No deaths and no radiosurgically induced adverse effects were observed, but in two cases there was slight hypesthesia (Group IV). The neuropathic component of the facial pain appeared to be poorly sensitive to radiosurgery. At the last follow-up examination, six patients (13.3%) exhibited recurrent pain, which was complete in four cases (8.8%) and partial in two (4.4%).
Conclusions. The results of GKS regarding facial pain control are very similar to those achieved by microsurgery according to series published in the literature. Nevertheless, the low rate of morbidity and the greater comfort afforded the patient render GKS safer and thus more attractive.