bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gamma knife surgery of superficially located meningioma
Authors: Kim Dong Gyu , Kim Chi Heon , Chung Hyun-Tai , Paek Sun Ha , Jeong Sang Soon , Han Dae Hee , Jung Hee-Won 
Published: May 2009

Object.The authors analyzed tumor control rates and complications in patients with superficially located meningiomas after gamma knife surgery (GKS).Methods.Between 1998 and 2003, GKS was performed in 23 patients with 26 lesions in whom follow-up imaging for 1 year or more was available. The male/female ratio was 1:22. The mean age was 59 years. The median tumor volume was 4.7 cm3, and the mean margin dose was 16 Gy at the 50% isodose line. Peritumoral edema was revealed on magnetic resonance (MR) imaging in four patients before GKS. Magnetic resonance imaging and clinical examinations were performed every 6 months after GKS. The mean follow-up duration was 32 months.The tumor shrank in eight cases, was stable in 17, and enlarged in one; thus 25 (95%) of 26 tumors were controlled. A peritumoral high signal on T2-weighted MR images was found in eight lesions and preexisting edema was aggravated in three lesions after GKS. Ten of these 11 patients complained of severe headache, and three patients experienced neurological deficits at the same time after a mean latency of 3 months; however, high signal was not demonstrated on imaging before 6 months on average. Steroid agents, when required, gave relief to all patients. The complication rate was 43% (10 of 23 cases). High signal disappeared in nine patients and decreased in the remaining two. High signal was associated with a high integral dose and a large tumor volume. Tumor shrinkage at the last follow-up examination was more prominent in the patients with symptomatic high signal (p = 0.03).Conclusions.There was a good tumor control rate with a high complication rate. Longer follow up of more patients is needed. Adjusting the dose—volume relationship should be considered to reduce complications.
Ultrastructural changes in arteriovenous malformations after gamma knife surgery: an electron microscopic study
Authors: Szeifert György T. , Major Ottó , Kemeny Andras A. 
Published: May 2009

Object.The authors analyzed morphological alterations at the subcellular level by undertaking transmission electron microscopy in arteriovenous malformations (AVMs) after gamma knife surgery (GKS).Methods.Histological, immunohistochemical, and electron microscopic investigations were performed in a series of pathological specimens obtained in seven patients. The patients harbored cerebral AVMs that had been previously treated with GKS and had suffered subsequent bleeding 10 to 52 months after treatment.Histological studies revealed spindle cell proliferation in the connective tissue stroma and in the subendothelial region of the irradiated AVM vessels. Electron microscopy demonstrated different ultrastructural characteristics of this spindle cell population. There were cells with a smooth-edged oval nuclei surrounded by massive bundles of collagen fibers in the extracellular matrix. Other cells with the same nuclear morphology contained abundant intracytoplasmic filaments. Nuclear deformation was connected to a fibrillary system developed within the cytoplasm, and peripheral attachment sites were related to an extracellular layer of basement membrane—like material arranged parallel to the cell border. Also present were cells containing well-developed cisterns of rough endoplasmic reticulum and dense bodies at the periphery of the cytoplasm with folded, irregular nuclei.Conclusions.The ultrastructural and histological characteristics of the spindle cell population in the GKS-treated AVMs are similar to those designated as myofibroblasts in wound healing processes and pathological fibromatoses. Because similar cell modifications have not been demonstrated in control nonirradiated AVM specimens, these myofibroblasts may contribute to the shrinking process and final occlusion of AVMs after radiosurgery.
Linear accelerator radiosurgery for vestibular schwannoma: measuring tumor volume changes on serial three-dimensional spoiled gradient-echo magnetic resonance images
Authors: Okunaga Tomohiro , Matsuo Takayuki , Hayashi Nobuyuki , Hayashi Yukishige , Shabani Hamisi K. , Kaminogo Makio , Ochi Makoto , Nagata Izumi 
Published: May 2009

Object
The authors report on a series of 46 patients harboring vestibular schwannomas (VSs) treated using linear accelerator (LINAC) radiosurgery and an analysis of serial magnetic resonance (MR) imaging data, specifically the changes in tumor volume.

Methods
Fifty-three consecutive patients underwent LINAC radiosurgery for VS between 1993 and 2002. Seven of these patients were lost to follow up. Three-dimensional (3D) spoiled gradient-echo (SPGR) MR imaging was performed at 3- to 4-month intervals after radiosurgery. Tumor volume was measured on Gd-enhanced MR images of each slice.
The median duration of follow-up MR imaging studies was 56.5 months (range 12–120 months). Follow-up imaging studies were conducted for longer than 1 year in 42 of 53 patients. Tumor volume changes were categorized into four types: enlargement (eight lesions [19%]), no change (two lesions [4.8%]), transient enlargement followed by shrinkage (19 lesions [45.2%]), and direct shrinkage (13 lesions [31%]). Two cases (4.8%) with twice the initial tumor volume required repeated radiosurgery. All cases of transient enlargement had subsequent shrinkage within 2 years after radiosurgery.
Nine (21.4%) of 42 patients demonstrated ventricular enlargement on MR images obtained after radiosurgery. Three patients (7.1%) required placement of a ventriculoperitoneal shunt because of symptomatic hydrocephalus, and another four cases (9.5%) spontaneously resolved.

Conclusions
Volume measurement on 3D-SPGR MR imaging was a suitable method to assess tumor changes. Volume changes beyond twofold or continuous enlargement for longer than 2 years after radiosurgery are key criteria in rating the effects of radiation. Some cases of hydrocephalus after radiosurgery resolved spontaneously and their rates of occurrence were similar to the typical incidence of hydrocephalus associated with VS.
Novel laser tissue-soldering technique for dural reconstruction
Authors: Gil Ziv , Shaham Amit , Vasilyev Tamar , Brosh Tamar , Forer Boaz , Katzir Abraham , Fliss Dan M. 
Published: May 2009

Object
The goal of this study was to use a modified version of the CO2 laser—soldering system to develop a simple and reliable technique for the repair of dural defects after excision of brain tumors.

Methods
The authors used a CO2 fiber optic laser system that they had developed for heating, monitoring, and controlling tissue temperature in situ and in real time, thereby reducing damage to the brain parenchyma. They adapted the system for dural closure by using free fascial grafts in a porcine model. Measures for estimation of reconstruction quality included visual assessment under magnification and direct measurements of adhesive strength and cerebrospinal fluid leak (CSF) pressure.
Reliable soldering was achieved in 54 of 57 experiments, providing a 95% success rate. The average peak adhesive strength was 82 ± 3 mN/cm2. The measured leak pressure of the fascia—dura mater bond was 66 ± 5 mm Hg. Conventional suturing performed using Prolene stitches resulted in immediate CSF leakage from areas between the stitches and from the area of the needle hole itself.

Conclusions
Fascia—dura mater soldering using the CO2 laser is feasible and may support CSF pressure up to six times higher than normal intracranial pressure. Findings of this study may provide a basis for the development of new tools for dural reconstruction.
Encapsulated vascular endothelial growth factor—secreting cell grafts have neuroprotective and angiogenic effects on focal cerebral ischemia
Authors: Yano Akimasa , Shingo Tetsuro , Takeuchi Akira , Yasuhara Takao , Kobayashi Kazuki , Takahashi Kazuya , Muraoka Kenichiro , Matsui Toshihiro , Miyoshi Yasuyuki , Hamada Hirofumi , Date Isao 
Published: May 2009

Object
The authors evaluated the neuroprotective and angiogenic effects of a continuous and low-dose infusion of vascular endothelial growth factor (VEGF)-165 on cerebral ischemia in rats.

Methods
The authors introduced VEGF complementary (c)DNA into baby hamster kidney (BHK) cells and established a cell line that produces human VEGF165 (BHK-VEGF). The BHK-VEGF cells and BHK cells that had been transfected with an expression vector that did not contain human VEGF165 cDNA (BHK-control) were encapsulated. Both capsules were implanted into rat striata. Six days after capsule implantation, the right middle cerebral artery (MCA) was occluded. Some animals were killed 24 hours after occlusion to measure the volume of the resulting infarct and to perform immunohistochemical studies. Other animals were used for subsequent behavioral studies 1, 7, and 14 days after MCA occlusion.
The encapsulated BHK-VEGF cell grafts significantly reduced the volume of the infarct and the number of apoptotic cells in the penumbral area when compared with the effect of the BHK-control cell capsule. In addition, angiogenesis and gliogenesis significantly increased in the region around the capsule in animals that received BHK-VEGF cell capsules without an increase in focal cerebral blood flow; this did not occur in animals that received the BHK-control cell capsule. In behavioral studies rats that received the BHK-VEGF cell capsule displayed significant recovery while participating in the accelerating rotarod test after stroke.

Conclusions
Continuous intracerebral administration of low-dose VEGF165 through encapsulated grafts of VEGF-producing cells produces neuroprotective and angiogenic effects. These effects improve subsequent motor function.
Gamma knife surgery for the treatment of intracranial metastases from breast cancer
Authors: Goyal Sharad , Prasad Dheerendra , Harrell Frank , Matsumoto Julie , Rich Tyvin , Steiner Ladislau 
Published: May 2009

Object. The goal of this study was to evaluate the effectiveness and limitations of gamma knife surgery (GKS) in the treatment of intracranial breast carcinoma lesions.
Methods. A retrospective analysis of the GKS database at the University of Virginia Health System identified 43 patients with a total of 84 lesions who were treated between 1989 and 2000. All patients who received treatment were included in this study. Imaging studies were available in 35 patients with 67 treated lesions.
The overall duration of median survival was 13 months (95% confidence interval [CI] 7–16 months) after radiosurgery. A univariable Cox regression analysis revealed that a single lesion (p = 0.035), a high Karnofsky Performance Scale (KPS) score (p = 0.019), and a high Score Index for Radiosurgery (SIR) in Brain Metastases (p = 0.036) were associated with a significantly lengthened time to local treatment failure. The median duration of survival for patients grouped according to the SIR as low, middle, and high was 3, 8, and 21 months, respectively (p = 0.00033). A multivariable analysis showed that a high KPS score (p = 0.006), a high SIR (p = 0.014), and advanced age (0.038) were predictive of survival. The 1-, 2-, 3-, and 5-year survival rates were 49, 23, 12, and 2%, respectively.
The overall median time to local treatment failure was 10 months (95% CI 6–14 months) after GKS. A univariable analysis demonstrated that a single lesion, higher KPS score, and a higher SIR were associated with a significantly longer time until local treatment failure. A multivariable analysis showed that a higher KPS score and SIR and patients who had received chemotherapy were associated with a significantly longer time to local treatment failure.
Neuroimaging scores given for the enhancement pattern (ring-enhancing, heterogeneous, and homogeneous signal), amount of necrosis (none, < 50%, and > 50%), and mass effect (none, mild, moderate, and severe) of each treated lesion did not correlate with survival or local treatment failure.
Conclusions. The SIR and the KPS score are prognostic factors in patients whose intracranial breast cancer metastases are treated with GKS. The SIR, which includes the KPS score, patient age, systemic disease status, largest lesion volume, and number of lesions, can be used to identify those patients with breast cancer metastasis who would benefit from GKS better than KPS score alone. The contribution of whole-brain radiation therapy to GKS with regard to local tumor control or survival could not be identified.
Surgical management of the recurrence and regrowth of craniopharyngiomas
Authors: Minamida Yoshihiro , Mikami Takeshi , Hashi Kazuo , Houkin Kiyohiro 
Published: May 2009

Object. The authors performed a retrospective analysis of a consecutive series of craniopharyngiomas and their recurrences, which were managed with surgery alone.
Methods. In the past 20 years, 37 consecutive patients with craniopharyngiomas underwent surgery without adjuvant radiotherapy. During that period there was a consistent strategy that surgical management was the first choice of treatment whenever possible.
Of these 37 patients, 11 experienced tumor recurrence (29.7%) during the mean follow-up period of 11.1 years. Of these 11 patients, seven experienced recurrence after neuroimaging-confirmed total removal, and four patients experienced recurrence after partial or incomplete removal. In these 11 patients, surgical removal was performed 17 times. Using a proper surgical approach (mainly a basal interhemispheric approach) and meticulous microsurgical techniques, total removal of the recurrent tumor was achieved in nine surgeries (52.9). The mortality and morbidity rates associated with these 17 surgeries were 0% and 9.1%, respectively. In most cases, visual function was preserved or improved and intellectual performance was also preserved.
Conclusions. Recurrence of craniopharyngioma can be safely managed by using meticulous contemporary microsurgical techniques without additional radiotherapy. The role of surgery and adjuvant radiotherapy for craniopharyngiomas may vary in the future, depending on innovations in treatment and technology. Nevertheless, surgery can be still a major therapeutic option in the management of recurrent craniopharyngiomas.
Association between elevated brain tissue glycerol levels and poor outcome following severe traumatic brain injury
Authors: Clausen Tobias , Alves Oscar Luis , Reinert Michael , Doppenberg Egon , Zauner Alois , Bullock Ross 
Published: May 2009

Object. Glycerol is considered to be a marker of cell membrane degradation and thus cellular lysis. Recently, it has become feasible to measure via microdialysis cerebral extracellular fluid (ECF) glycerol concentrations at the patient's bedside. Therefore the aim of this study was to investigate the ECF concentration and time course of glycerol after severe traumatic brain injury (TBI) and its relationship to patient outcome and other monitoring parameters.
Methods. As soon as possible after injury for up to 4 days, 76 severely head-injured patients were monitored using a microdialysis probe (cerebral glycerol) and a Neurotrend sensor (brain tissue PO2) in uninjured brain tissue confirmed by computerized tomography scanning. The mean brain tissue glycerol concentration in all monitored patients decreased significantly from 206 ± 31 µmol/L on Day 1 to 9 ± 3 µmol/L on Day 4 after injury (p < 0.0001). Note, however, that there was no significant difference in the time course between patients with a favorable outcome (Glasgow Outcome Scale [GOS] Scores 4 and 5) and those with an unfavorable outcome (GOS Scores 1–3). Significantly increased glycerol concentrations were observed when brain tissue PO2 was less than 10 mm Hg or when cerebral perfusion pressure was less than 70 mm Hg.
Conclusions. Based on results in the present study one can infer that microdialysate glycerol is a marker of severe tissue damage, as seen immediately after brain injury or during profound tissue hypoxia. Given that brain tissue glycerol levels do not yet add new clinically significant information, however, routine monitoring of this parameter following traumatic brain injury needs further validation.
Predictive value of an early Glasgow Outcome Scale score: 15-month score changes
Authors: Miller Kelly J. , Schwab Karen A. , Warden Deborah L. 
Published: May 2009

Object. Does an early Glasgow Outcome Scale (GOS) assessment provide a reliable indicator of later outcome in a patient with traumatic brain injury (TBI)? The authors examined the utility of the GOS during early treatment as a predictor of outcome score 15 months postinjury by analyzing outcome score change in a group of patients with closed head injuries.
Methods. Glasgow Outcome Scale scores assessed within 3 months of injury (baseline) were compared with scores obtained at 15 months postinjury in 121 patients, primarily young military personnel. Score changes between baseline and 8 months postinjury were also studied in a subgroup of 72 patients. The impact of initial injury severity (determined by the duration of unconsciousness) on score change was also explored. The GOS scores at three time points within the 15-month period—baseline (within 3 months of injury), 8, and 15 months postinjury—were examined to ascertain when the maximal GOS score had been reached.
Conclusions. Baseline GOS score was a reliable predictor of outcome in patients with an initial score of 5 (no disability) or 4 (mild disability), but not in patients with an initial score of 3 (severe disability). Patients who remained unconscious for more than 24 hours did not have significantly lower outcome scores than those who experienced loss of consciousness for less than 24 hours at 15 months postinjury. Interestingly, the duration of unconsciousness did not affect the likelihood of an improved score during the study period in patients with a GOS score of 3 or 4 at baseline. An updated evaluation conducted after the early phases of treatment is needed to provide a realistic prognosis of severe TBI.
Coexpression of erythropoietin and its receptor in endolymphatic sac tumors
Authors: Vogel Timothy W. A. , Vortmeyer Alexander O. , Lubensky Irina A. , Lee Youn-Soo , Furuta Makoto , Ikejiri Barbara , Kim H. Jeffrey , Lonser Russell R. , Oldfield Edward H. , Zhuang Zhengping 
Published: May 2009

Object.Von Hippel—Lindau (VHL) disease is characterized by multiple tumors in specific organs. The cell of origin and the reason for the particular organ distribution of the tumors remains unknown. Endolymphatic sac tumor (ELST) is one of the lesions associated with VHL disease. Data from previous studies of VHL disease—associated hemangioblastomas (HBs) and renal cell carcinomas (RCCs) have indicated thatVHLgene deficiency causes coexpression of erythropoietin (Epo) and its receptor (Epo-R), which facilitates tumor growth.Methods.The authors studied ELSTs from five patients with VHL germline mutations. Analysis of the five ELST samples revealed loss of the wild-type allele, consistent with Knudson's two-hit hypothesis for tumorigenesis. All five ELST specimens were characterized microscopically and by immunohistochemical analysis. Coexpression of Epo and Epo-R was found in all five tumors on immunohistochemical studies and confirmed through reverse transcription—polymerase chain reaction and Western blot analysis.Conclusions.Expression of Epo appears to be a result ofVHLgene deficiency, whereas the simultaneous coexpression of Epo-R may reflect a developmental mechanism of tumorigenesis. Coexpression of Epo and Epo-R in ELSTs together with the morphological and genetic similarities of these lesions with other VHL disease—associated tumors indicates that VHL disease—associated tumors in different organs share common pathogenetic pathways.
Survival and differentiation of neural progenitor cells derived from embryonic stem cells and transplanted into ischemic brain
Authors: Takagi Yasushi , Nishimura Masaki , Morizane Asuka , Takahashi Jun , Nozaki Kazuhiko , Hayashi Junya , Hashimoto Nobuo 
Published: May 2009

Object. Cell replacement therapy including the use of embryonic stem cells (ESCs) may represent a novel treatment for damage from stroke. In this study, the authors transplanted neural progenitor cells (NPCs) derived from ESCs into ischemic brain and analyzed their survival and differentiation.
Methods. Multipotential NPCs were generated from ESCs by using the stromal cell—derived inducing activity method. These cells could differentiate in vitro into neurons, glia, and oligodendrocytes, thus revealing them to be neural stem cells. The NPCs were then transplanted into ischemic brain. At 2 weeks postischemia, the transplanted cells occupied 18.8 ± 2.5% of the hemispheric area; by 4 weeks postischemia, 26.5 ± 4% of the hemisphere. At 4 weeks after transplantation, green fluorescent protein (GFP)—positive transplanted cells showed mature neuronal morphological features. The authors also investigated the expression of differentiation markers and various neurotransmitters. Transplanted cells were immunopositive for neuronal nuclei, β-tubulin-III, and glial fibrillary acidic protein. Of the GFP-positive cells, 33.3 ± 11.5% were positive for glutamate decarboxylase, 13.3 ± 5.8% for glutamate, 2.1 ± 2.5% for tyrosine hydroxylase, 1.8 ± 2% for serotonin, and 0.4 ± 0.2% for choline acetyltransferase.
Conclusions. The authors confirmed the survival and differentiation of ESC-derived NPCs transplanted into the ischemic brain. Surviving transplanted cells expressed several neural markers and neurotransmitters. These findings indicate that these cells can function in the brain.
Surface properties, more than size, limiting convective distribution of virus-sized particles and viruses in the central nervous system
Authors: Chen Michael Y. , Hoffer Alan , Morrison Paul F. , Hamilton John F. , Hughes Jeffrey , Schlageter Kurt S. , Lee Jeongwu , Kelly Brandon R. , Oldfield Edward H. 
Published: May 2009

Object. Achieving distribution of gene-carrying vectors is a major barrier to the clinical application of gene therapy. Because of the blood—brain barrier, the distribution of genetic vectors to the central nervous system (CNS) is even more challenging than delivery to other tissues. Direct intraparenchymal microinfusion, a minimally invasive technique, uses bulk flow (convection) to distribute suspensions of macromolecules widely through the extracellular space (convection-enhanced delivery [CED]). Although acute injection into solid tissue is often used for delivery of oligonucleotides, viruses, and liposomes, and there is preliminary evidence that certain of these large particles can spread through the interstitial space of the brain by the use of convection, the use of CED for distribution of viruses in the brain has not been systematically examined. That is the goal of this study.
Methods. Investigators used a rodent model to examine the influence of size, osmolarity of buffering solutions, and surface coating on the volumetric distribution of virus-sized nanoparticles and viruses (adeno-associated viruses and adenoviruses) in the gray matter of the brain. The results demonstrate that channels in the extracellular space of gray matter in the brain are large enough to accommodate virus-sized particles and that the surface characteristics are critical determinants for distribution of viruses in the brain by convection.
Conclusions. These results indicate that convective distribution can be used to distribute therapeutic viral vectors in the CNS.