bluuebunny/crossref_metadata_2025_split huggingface dataset:
Products of hemolysis in the subarachnoid space inducing spreading ischemia in the cortex and focal necrosis in rats: a model for delayed ischemic neurological deficits after subarachnoid hemorrhage?
Authors: Dreier Jens P. , Ebert Natalie , Priller Josef , Megow Dirk , Lindauer Ute , Klee Rolf , Reuter Uwe , Imai Yoshinori , Einhäupl Karl M. , Victorov Ilya , Dirnagl Ulrich 
Published: May 2009

Object. The pathogenesis of delayed ischemic neurological deficits after subarachnoid hemorrhage has been related to products of hemolysis. Topical brain superfusion of artificial cerebrospinal fluid (ACSF) containing the hemolysis products K+ and hemoglobin (Hb) was previously shown to induce ischemia in rats. Superimposed on a slow vasospastic reaction, the ischemic events represent spreading depolarizations of the neuronal—glial network that trigger acute vasoconstriction. The purpose of the present study was to investigate whether such spreading ischemias in the cortex lead to brain damage.Methods. A cranial window was implanted in 31 rats. Cerebral blood flow (CBF) was measured using laser Doppler flowmetry, and direct current (DC) potentials were recorded. The ACSF was superfused topically over the brain. Rats were assigned to five groups representing different ACSF compositions. Analyses included classic histochemical and immunohistochemical studies (glial fibrillary acidic protein and ionized calcium binding adaptor molecule) as well as a terminal deoxynucleotidyl transferase—mediated deoxyuridine triphosphate nick-end labeling assay.Superfusion of ACSF containing Hb combined with either a high concentration of K+ (35 mmol/L, 16 animals) or a low concentration of glucose (0.8 mmol/L, four animals) reduced CBF gradually. Spreading ischemia in the cortex appeared when CBF reached 40 to 70% compared with baseline (which was deemed 100%). This spreading ischemia was characterized by a sharp negative shift in DC, which preceded a steep CBF decrease that was followed by a slow recovery (average duration 60 minutes). In 12 of the surviving 14 animals widespread cortical infarction was observed at the site of the cranial window and neighboring areas in contrast to findings in the three control groups (11 animals).Conclusions. The authors conclude that subarachnoid Hb combined with either a high K+ or a low glucose concentration leads to widespread necrosis of the cortex.
Sellar reconstruction with resorbable vicryl patches, gelatin foam, and fibrin glue in transsphenoidal surgery: a 10-year experience with 376 patients
Authors: Seiler Rolf W. , Mariani Luigi 
Published: May 2009

Object. Closure of the sella turcica after transsphenoidal surgery is mainly accomplished with autologous muscle fascia and fat or muscle; this requires a second surgical incision. The authors review the results of using resorbable vicryl patches, gelatin foam, and fibrin glue for sellar reconstruction.Methods. A review was conducted of 376 consecutive patients who underwent surgery for pituitary adenomas, cysts, or subdiaphragmatic craniopharyngiomas in the sella turcica that the senior author (R.W.S.) had performed or directly supervised over the last 10 years. The sellar reconstruction was performed with a commercially available, synthetic absorbable patch composed of polyglactin 910/poly-p-dioxanone, gelatin foam, and fibrin glue. The patch is essentially resorbed in 2 to 3 months and replaced by fibrous collagen tissue. There were 117 small, 112 medium-sized, and 147 large lesions. The overall nonendocrine postoperative morbidity rate was 2.8%, and included visual deterioration, meningitis, secondary epistaxis, nasal septum complication, and cerebrospinal fluid (CSF) leakage. Two patients with macroadenomas needed reoperation for persistent CSF leakage, which comprised 0.5% of the whole series or 0.8% of the 259 patients with medium-sized or large lesions. There was no mortality and no morbidity related to the implanted material, and in particular no delayed empty sella syndrome.Conclusions. Closure of the sella turcica with a synthetic absorbable vicryl patch, gelatin foam, and fibrin glue after transsphenoidal surgery is safe and very effective in preventing postoperative CSF fistulas. The use of this technique obviates the need for a second surgical incision and shortens the operating time. Because of the progressive resorption of the substitute material, the interpretation of postoperative magnetic resonance studies was not significantly hindered.
Functional magnetic resonance imaging of somatosensory cortex activity produced by electrical stimulation of the median nerve or tactile stimulation of the index finger
Authors: Boakye Maxwell , Huckins Sean C. , Szeverenyi Nikolaus M. , Taskey Bobby I. , Hodge Charles J. 
Published: May 2009

Object. Functional magnetic resonance (fMR) imaging was used to determine patterns of cerebral blood flow changes in the somatosensory cortex that result from median nerve stimulation (MNS).Methods. Ten healthy volunteers underwent stimulation of the right median nerve at frequencies of 5.1 Hz (five volunteers) and 50 Hz (five volunteers). The left median nerve was stimulated at frequencies of 5.1 Hz (two volunteers) and 50 Hz (five volunteers). Tactile stimulation (with a soft brush) of the right index finger was also applied (three volunteers). Functional MR imaging data were transformed into Talairach space coordinates and averaged by group. Results showed significant activation (p < 0.001) in the following regions: primary sensorimotor cortex (SMI), secondary somatosensory cortex (SII), parietal operculum, insula, frontal cortex, supplementary motor area, and posterior parietal cortices (Brodmann's Areas 7 and 40). Further analysis revealed no statistically significant difference (p > 0.05) between volumes of cortical activation in the SMI or SII resulting from electrical stimuli at 5.1 Hz and 50 Hz. There existed no significant differences (p > 0.05) in cortical activity in either the SMI or SII resulting from either left- or right-sided MNS. With the exception of the frontal cortex, areas of cortical activity in response to tactile stimulation were anatomically identical to those regions activated by electrical stimulation. In the SMI and SII, activation resulting from tactile stimulation was not significantly different (p > 0.05) from that resulting from electrical stimulation.Conclusions. Electrical stimulation of the median nerve is a reproducible and effective means of activating multiple somatosensory cortical areas, and fMR imaging can be used to investigate the complex network that exists between these areas.
Long-term testing of an intracranial pressure monitoring device
Authors: Kroin Jeffrey S. , McCarthy Robert J. , Stylos Lee , Miesel Keith , Ivankovich Anthony D. , Penn Richard D. 
Published: May 2009

Object. Long-term monitoring of intracranial pressure (ICP) is limited by the lack of an implantable sensor with low drift. The goal of this study was to demonstrate that a new capacitive transducer system will produce accurate and stable ICP records over extended periods.Methods. Intracranial pressure sensors were implanted into the frontal white matter of four dogs. In addition, a fluid-filled catheter was placed in the cisterna magna (CM) to measure cerebrospinal fluid (CSF) pressure. The animals were tested using standard physiological maneuvers such as jugular vein compression, head elevation, and CSF withdrawal from and saline injection into the CM to verify that the ICP sensor precisely matched CSF pressure changes. The mean ICP pressure and CM pressure were compared for months to demonstrate that the transducer system produced minimal drift over time.The change in the ICP sensor record closely duplicated that of the CSF waveform in the CM in response to well-known physiological stimuli. More important, mean ICP pressure remained within 3 mm Hg of CM pressure for months, with a mean difference of less than 0.3 mm Hg. Histological examination of the dog brains revealed only minimal tissue reaction to the presence of the sensor.Conclusions. The authors demonstrate a new implantable solid-state sensor that reliably measures ICP for months, with minimal drift. The clinical application of this sensor and its telemetry is for long-term monitoring of patients with head injury, mass lesions, and hydrocephalus.
The impact of age and gender on the incidence of glial tumors in New York state from 1976–1995
Authors: McKinley Brian P. , Michalek Arthur M. , Fenstermaker Robert A. , Plunkett Robert J. 
Published: May 2009

Object. In this study the authors describe secular trends in the incidence of three glial tumors—glioblastoma multiforme (GBM), astrocytoma not otherwise specified (ANOS), and anaplastic astrocytoma (AA)—in New York state from 1976 through 1995. They also describe the effect of age and sex on the relative risk (RR) for these tumors, specifically GBM.Methods. Crude, age-, and sex-specific incidence rates were calculated for each tumor type from 1976 to 1995 by using data from the New York State Cancer Registry. Age-adjusted incidence rates were calculated by the direct standardization procedure, in which the 1970 United States Census Population Standard Million is used. The RR of GBM for the female population was calculated and plotted. Statistical comparisons were made using Pearson's correlation coefficient and regression analysis with the coefficient of variation.Conclusions. The age-adjusted incidence of these three glial tumors increased during the study period. Increases in age-specific incidence of GBM were primarily limited to patients 60 years of age or older. The reasons for these increases cannot be fully explained with the data. Those in the female population had a lower risk of developing these tumors than those in the male. For GBM, the protective effect of sex was first evident at the approximate age of menarche, was greatest at the approximate age of menopause, and decreased in postmenopausal age strata. The overall protective effect of female sex and the described trend in RR for GBM in the female population suggests that sex hormones and/or genetic differences between males and females may play a role in the pathogenesis of this tumor.
Primary intracerebral and aneurysmal subarachnoid hemorrhage in Izumo City, Japan. Part II: management and surgical outcome
Authors: Inagawa Tetsuji , Shibukawa Masaaki , Inokuchi Futoshi , Tokuda Yoshio , Okada Yoshikazu , Okada Kazunori 
Published: May 2009

Object. The purpose of this study was to assess the overall management and surgical outcome of primary intracerebral hemorrhage (ICH) and aneurysmal subarachnoid hemorrhage (SAH) among the 85,000 residents of Izumo City, Japan.Methods. During 1991 through 1996, 267 patients with ICH and 123 with SAH were treated in Izumo. Of the 267 patients with ICH, 25 underwent hematoma removal by open craniotomy or suboccipital craniectomy and 34 underwent stereotactic evacuation of the hematoma, whereas aneurysm clipping was performed in 71 of the 123 patients with SAH; operability rates were thus 22% for ICH and 58% for SAH (p < 0.0001). The overall 30-day survival rates were 86% for ICH and 66% for SAH (p < 0.0001) and the 2-year survival rates were 73% and 62% (p = 0.0207), respectively. In patients who underwent surgery, 30-day and 2-year survival rates were 93% for ICH and 100% for SAH (p = 0.0262), and 75% for ICH and 97% for SAH (p = 0.0002), respectively. In patients with ICH, the most important predictors of 30-day case-fatality rates were the volume of the hematoma, the Glasgow Coma Scale (GCS) score, rebleeding, and midline shifting, whereas those for 2-year survival were the GCS score, age, rebleeding, and hematoma volume. In patients with SAH, the most important determinants of 30-day case-fatality rates were the GCS score and age, whereas only the GCS score had a significant impact on 2-year survival.Conclusions. The overall survival rates for patients with ICH or SAH in Izumo were more favorable than those in previously published epidemiological studies. However, despite improved surgical results, the overall management of ICH and SAH still produced an unsatisfactory outcome, mainly because of primary brain damage.
GFP labelled ES cell derived neural precursor cells differentiate into Thy-1 positive neurons and glia after transplantation into the striatum of the adult rat striatum
Authors: Arnhold Stefan , Lenartz Doris , Kruttwig Klaus , Klinz Franz-Josef , Kolossov Eugen , Hescheler Jürgen , Sturm Volker , Andressen Christian , Addicks Klaus 
Published: May 2009

Object. The aim of this investigation was to assess new information concerning the capacity of transplanted embryonic stem cell (ESC)-derived neuronal cells to migrate into host brain and to evaluate these cells as a possible source for cell replacement therapy in neurodegenerative disorders such as Parkinson's disease (PD).Methods. The authors investigated the ability of ESC-derived neural precursor cells to migrate and differentiate in a host striatum by using a D3-derived ESC clone that was transfected stably with a chicken β-actin cytomegalovirus enhancer—driven green fluorescent protein (GFP)-labeled construct. This procedure allowed easy monitoring of all transplanted cells because of the green fluorescent labeling of donor cells. This approach also afforded easy estimation of cell integration and simultaneous observation of the entire transplanted cell population in relation to immunocytochemically identified neuronal and glial differentiation. After selection of nestin-positive neural precursor cells in a synthetic medium, they were implanted into the striatum of male adult Wistar rats. Their integration was analyzed on morphological studies performed 3 days to 4 weeks posttransplantation.Conclusions. The investigators found that after transplantation, a subpopulation of GFP-labeled cells differentiated into various neural morphological types that were positive for the mouse-specific Thy-1 antigen, which is known be expressed on neurons, as well as being positive for the astroglial marker glial fibrillary acidic protein. Moreover, GFP-expressing cells that were negative for either of these markers remained close to the injection site, presumably representing other derivatives of the neural lineage. Together, these findings contribute to basic research regarding future transplantation strategies in neurodegenerative diseases such as PD.
Clinical outcomes after stereotactic radiosurgery for idiopathic trigeminal neuralgia
Authors: Maesawa Satoshi , Salame Camille , Flickinger John C. , Pirris Stephen , Kondziolka Douglas , Lunsford L. Dade 
Published: May 2009

Object. Stereotactic radiosurgery is an increasingly used and the least invasive surgical option for patients with trigeminal neuralgia. In this study, the authors investigate the clinical outcomes in patients treated with this procedure.
Methods. Independently acquired data from 220 patients with idiopathic trigeminal neuralgia who underwent gamma knife radiosurgery were reviewed. The median age was 70 years (range 26–92 years). Most patients had typical features of trigeminal neuralgia, although 16 (7.3%) described additional atypical features. One hundred thirty-five patients (61.4%) had previously undergone surgery and 80 (36.4%) had some degree of sensory disturbance related to the earlier surgery.
Patients were followed for a maximum of 6.5 years (median 2 years). Complete or partial relief was achieved in 85.6% of patients at 1 year. Complete pain relief was achieved in 64.9% of patients at 6 months, 70.3% at 1 year, and 75.4% at 33 months. Patients with an atypical pain component had a lower rate of pain relief (p = 0.025). Because of recurrences, only 55.8% of patients had complete or partial pain relief at 5 years. The absence of preoperative sensory disturbance (p = 0.02) or previous surgery (p = 0.01) correlated with an increased proportion of patients who experienced complete or partial pain relief over time. Thirty patients (13.6%) reported pain recurrence 2 to 58 months after initial relief (median 15.4 months). Only 17 patients (10.2% at 2 years) developed new or increased subjective facial paresthesia or numbness, including one who developed deafferentation pain.
Conclusions. Radiosurgery for idiopathic trigeminal neuralgia was safe and effective, and it provided benefit to a patient population with a high frequency of prior surgical intervention.
Magnetic resonance spectroscopy of brain hemangiopericytomas: high myoinositol concentrations and discrimination from meningiomas
Authors: Barba Ignasi , Moreno Ángel , Martínez-Pérez Irene , Tate Anne Rosemary , Cabañas Miquel E. , Baquero Miguel , Capdevila Antoni , Arús Carles 
Published: May 2009

Object. Hemangiopericytomas are a rare type of brain tumor that are very similar to meningiomas in appearance and symptoms but require different treatment. It is not normally possible to distinguish between them by using magnetic resonance (MR) imaging and computerized tomography studies. However, discrimination may be possible by using in vivo MR spectroscopy (MRS) because the biochemical composition of these two lesions is different. The goal of this study was to describe the use of MRS in discriminating between these similar tumor types.
Methods. In vivo MRS spectra were acquired in 27 patients (three with hemangiopericytomas and 24 with meningiomas) by using a single-voxel proton brain examination system at 1.5 teslas with short— (20-msec) and long— (135-msec) echo times. In addition, brain biopsy specimens obtained by open craniotomy were frozen within 5 minutes of resection and stored in liquid nitrogen until they were used. The specimens were powdered, extracted with perchloric acid, redissolved in 2H2O, and high-resolution in vitro MRS was used at 9.4 teslas to record their spectra.
Conclusions. In this study the authors show that hemangiopericytomas could be clearly distinguished from meningiomas because they have a larger peak at 3.56 ppm. Measurements of extracts of the tumors and comparison of spectra acquired with MRS at long— (135-msec) and short— (20-msec) echo times established that this was due to the much higher levels of myoinositol in the hemangiopericytomas.
Tracking the invasiveness of human astrocytoma cells by using green fluorescent protein in an organotypical brain slice model
Authors: Jung Shin , Ackerley Cameron , Ivanchuk Stacey , Mondal Soma , Becker Laurence E. , Rutka James T. 
Published: May 2009

Object. Although it is known that malignant astrocytomas infiltrate diffusely into regions of normal brain, it is frequently difficult to identify unequivocally the solitary, invading astrocytoma cell in histopathological preparations or experimental astrocytoma models. The authors describe an experimental system that facilitates the tracking of astrocytoma cells by using nonneoplastic cerebral tissue as the substrate for invasion.
Methods. Cerebral tissue was cut into 1-mm-thick slices and cultured in the upper chamber of a Transwell culture dish on top of a polyester membrane (0.4-mm pore size) that was bathed in medium supplied by the lower chamber. Two astrocytoma cell lines, U-87 MG (U87) and U343 MG-A (U343), were selected because of their differing basal cell motilities in monolayer cultures. The astrocytoma cells were stably transfected with vectors that expressed green fluorescent protein (GFP), either alone or as a fusion protein with the receptor for hyaluronic acid—mediated motility (RHAMM) in either sense or antisense orientations. Stably transfected clones that had high levels of GFP expression were selected using the direct visualization provided by fluorescence microscopy and fluorescence-activated cell-sorter analysis. The GFP-expressing astrocytoma cell clones were implanted into the center of the brain slice and the degree of astrocytoma invasion into brain tissue was measured at different time points by using the optical sectioning provided by the confocal laser microscope. The authors observed that GFP-expressing astrocytoma cells could be readily tracked and followed in this model system. Individual astrocytoma cells that exhibited green fluorescence could be readily identified following their migration through the brain slices. The GFP-labeled U87 astrocytoma cells migrated farther into the brain slice than the U343 astrocytoma cells. The RHAMM-transfected GFP-labeled astrocytoma cells also infiltrated farther than the GFP-labeled astrocytoma cells themselves. The expression of antisense RHAMM virtually abrogated the invasion of the brain slices by both astrocytoma cell lines.
Conclusions. The authors believe that this organotypical culture system may be of considerable utility in studying the process of astrocytoma invasion, not only because it provides a better representation of the extracellular matrix molecules normally encountered by invading astrocytoma cells, but also because the GFP tag enables tracking of highly migratory and invasive astrocytoma cells under direct vision.
Delayed induction and long-term effects of mild hypothermia in a focal model of transient cerebral ischemia: neurological outcome and infarct size
Authors: Maier Carolina M. , Sun Guo Hua , Kunis David , Yenari Midori A. , Steinberg Gary K. 
Published: May 2009

Object. The goals of this study were to determine the effects of delaying induction of mild hypothermia (33°C) after transient focal cerebral ischemia and to ascertain whether the neuroprotective effects of mild hypothermia induced during the ischemic period are sustained over time.
Methods. In the first study, rats underwent 2 hours of middle cerebral artery (MCA) occlusion. Animals in one group were maintained under normothermic conditions (N group, 23 rats) throughout the period of ischemia and reperfusion. Rats in four additional groups were exposed to 2 hours of hypothermia, which commenced at ischemia onset (H0 group, 11 rats) or with delays of 90 (H90 group, 10 rats), 120 (H120 group, 10 rats), or 180 (H180 group, five rats) minutes, and allowed to survive for 3 days. In the second study, animals underwent 1.5 hours of MCA occlusion and were maintained under normothermic (48 rats) or hypothermic (44 rats) conditions during the ischemia period, after which they survived for 3 days, 1 week, or 2 months. All animals were evaluated for neurological findings at 24 hours and 48 hours postischemia and before they were killed. Regions of infarct were determined by examining hematoxylin and eosinstained brain slices obtained at six coronal levels.
Conclusions. Mild hypothermia conferred significant degrees of neuroprotection in terms of survival, behavioral deficits, and histopathological changes, even when its induction was delayed by 120 minutes after onset of MCA occlusion (p < 0.05) compared with normothermic conditions. Furthermore, the neuroprotective effect of mild hypothermia (2-hour duration) that was induced during the ischemia period was sustained over 2 months. These studies lend further support to the use of mild hypothermia in the treatment of stroke.