bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trigeminal evoked potentials in somatosensory cortex of the Macaca mulatta
Authors: McCarthy Gregory , Allison Truett 
Published: June 2009

✓ Somatosensory evoked potentials (SEPs) obtained in response to stimulation of the median nerve, posterior tibial nerve, lips, tongue, palate, and pharynx were recorded in four monkeys (Macaca mulatta) under light barbiturate anesthesia. In agreement with the results of SEP recordings in humans and single-unit recordings in monkeys, there is a medial-to-lateral representation in somatosensory cortex of the hand, lips, and tongue. There is a discontinuity in the representation of the upper mouth: the tongue representation is interposed between a medial region (near the lip representation), usually representing the lateral hard palate and gum, and a lateral region (near the lateral sulcus), usually representing the central hard palate. For all types of trigeminal stimulation, root mean square (RMS) voltage maps show maxima over somatosensory cortex. Laminar recordings demonstrated that trigeminal SEPs recorded from the cortical surface are generated in somatosensory cortex in areas 1, 2, and 3b.
Median nerve and posterior tibial nerve stimulation did not evoke SEPs in the surface cortex near the lateral sulcus, suggesting that the most lateral portion of the postcentral gyrus is not a part of the second somatosensory area (SII). This lateral region may contain the representation of posterior intraoral structures, but it was not possible to confirm this assumption by stimulation of the soft palate or pharynx.
Differential effects of vincristine and phenytoin on the proliferation, migration, and invasion of human glioma cell lines
Authors: Tonn Jörg-Christian , Haugland Hans Kristian , Saraste Jaakko , Roosen Klaus , Laerum Ole Didrik 
Published: June 2009

✓ The aim of this study was to investigate the antimigratory and antiinvasive potential of vincristine sulfate (VCR) on human glioma cells and to analyze whether phenytoin (5,5-diphenylhydantoin; DPH) might act synergistically with VCR. Vincristine affects the cytoplasmic microtubules; DPH has been reported to enhance VCR cytotoxicity in murine cells. In two human glioma cell lines, GaMG and D-37MG, we found VCR to reduce monolayer growth and colony formation in a dose-dependent fashion at concentrations of 10 ng/ml and above. Phenytoin increased the cytotoxic and cystostatic effects of VCR in monolayer cells but not in spheroids.Multicellular spheroids were used to investigate directional migration. A coculture system of GaMG and D-37MG spheroids with fetal rat brain aggregates was used to analyze and quantify tumor cell invasion. A dose-dependent inhibition of migration and invasion by VCR was observed in both cell lines without further enhancement by DPH. Immunofluorescence microscopy with antibodies against α-tubulin revealed dose-dependent morphological alterations in the microtubules when the cells were exposed to VCR but not after incubation with DPH. Based on the combination of standardizedin vitromodel systems currently in use and the present data, the authors strongly suggest that VCR inhibits migration and invasion of human glioma cells. This is not altered by DPH, which inhibits cell proliferation in combination with VCR.
Papillary craniopharyngioma: a clinicopathological study of 48 cases
Authors: Crotty Thomas B. , Scheithauer Bernd W. , Young William F. , Davis Dudley H. , Shaw Edward G. , Miller Gary M. , Burger Peter C. 
Published: June 2009

✓ Two distinct clinicopathological variants of craniopharyngioma exist: the classic adamantinomatous type and a recently described papillary form that predominates in adults and reportedly behaves in a less aggressive manner. The present study describes the clinicopathological features of 48 patients with papillary craniopharyngioma treated at the Mayo Clinic between 1910 and 1994. An additional four tumors were found to have histological features of both adamantinomatous and papillary craniopharyngioma. Whereas adamantinomatous tumors typically occur in adolescent patients, the mean age of the 48 patients (23 males and 25 females) with papillary craniopharyngioma was 44.7 years (range 10 to 74 years). Presenting clinical features included visual impairment (84%), headache (68%), and pituitary insufficiency (anterior 42%; posterior 27%). Preoperative computerized tomography (CT) and magnetic resonance (MR) imaging in 17 patients typically revealed a noncalcified, partially cystic mass that enhanced peripherally and contained mural nodules (67%). Many (41%) of the lesions involved or extended into the third ventricle on imaging. At first surgery, gross total tumor removal was achieved in 17 patients (36%) and subtotal resection in 30 patients (64%) in whom tumor resection was attempted. Tumor recurrence was noted in two patients who underwent gross total removal. Tumor-free survival rates of 100% and 78% were obtained in patients who underwent gross total and subtotal resection at initial surgery, respectively. Postoperative radiation therapy was beneficial to patients having undergone a subtotal resection, with an increase in tumor-free survival from 26% to 86%.
Aside from well-documented morphological distinctions, papillary craniopharyngiomas differ from adamantinomatous tumors in several important respects. These include the almost exclusive occurrence of papillary tumors in adulthood and their more uniform appearance on both CT and MR imaging. However, a preliminary analysis of our data suggests there are no significant differences between the two lesions with respect to resectability, efficacy of radiation therapy, and overall survival.
Spinal tuberculosis: a diagnostic and management challenge
Authors: Nussbaum Eric S. , Rockswold Gaylan L. , Bergman Thomas A. , Erickson Donald L. , Seljeskog Edward L. 
Published: June 2009

✓ The authors reviewed 29 cases of spinal tuberculosis treated from 1973 to 1993 with an average follow-up time of 7.4 years. Clinical findings included back pain, paraparesis, kyphosis, fever, sensory disturbance, and bowel and bladder dysfunction. Twenty-two patients (76%) presented with neurological deficit; 12 (41%) were initially misdiagnosed. Sixteen patients (55%) had predominant vertebral body involvement; nine had marked bone collapse with neurological compromise. Eleven individuals (39%) had intraspinal granulomatous tissue causing neurological dysfunction in the absence of bone destruction, and two (7%) had intramedullary tuberculomas.All patients received antituberculous medications: 13 were initially treated with bracing alone, eight underwent laminectomy and debridement of extra- or intradural granulomatous tissue, and eight underwent anterior, posterior, or combined fusion procedures. No patient with neurological deficit recovered or stabilized with nonoperative management. Thirteen patients were readmitted with progression of inadequately treated osteomyelitis; 12 (92%) of these required new or more radical fusion procedures. Anterior fusion failure was associated with marked preoperative kyphosis and multilevel disease requiring a graft that spanned more than two disc spaces. Courses of antibiotic medications shorter than 6 months were invariably associated with disease recurrence.It was concluded that 1) patients should receive at least 12 months of appropriate antituberculous therapy; 2) individuals with neurological deficit should undergo surgical decompression; 3) laminectomy and debridement are adequate for intraspinal granulomatous tissue in the absence of significant bone destruction; 4) when vertebral body involvement has produced wedging and kyphosis, aggressive debridement and fusion are indicated to prevent delayed instability and progression of disease.
Magnetic resonance image—directed stereotactic neurosurgery: use of image fusion with computerized tomography to enhance spatial accuracy
Authors: Alexander Eben , Kooy Hanne M. , van Herk Marcel , Schwartz Marc , Barnes Patrick D. , Tarbell Nancy , Mulkern Robert V. , Holupka Edward J. , Loeffler Jay S. 
Published: June 2009

✓ Distortions of the magnetic field, such as those caused by susceptibility artifacts and peripheral magnetic field warping, can limit geometric precision in the use of magnetic resonance (MR) imaging in stereotactic procedures. The authors have routinely found systematic error in MR stereotactic coordinates with a median of 4 mm compared to computerized tomography (CT) coordinates. This error may place critical neural structures in jeopardy in some procedures. A description is given of an image fusion technique that uses a chamfer matching algorithm; the advantages of MR imaging in anatomical definition are combined with the geometric precision of CT, while eliminating most of the anatomical spatial distortion of stereotactic MR imaging.
A stereotactic radiosurgical case is presented in which the use of MR localization alone would have led to both irradiation of vital neural structures outside the desired target volume and underdose of the intended target volume. The image fusion approach allows for the use of MR imaging, combined with stereotactic CT, as a reliable localizing technique for stereotactic neurosurgery and radiosurgery.
Immunolocalization of cathepsin B in human glioma: implications for tumor invasion and angiogenesis
Authors: Mikkelsen Tom , Yan Pei-Sha , Ho Khang-Loon , Sameni Mansoureh , Sloane Bonnie F. , Rosenblum Mark L. 
Published: June 2009

✓ The poor prognosis of patients with malignant gliomas is at least partially due to the invasive nature of these tumors. In this study, the authors investigated the possibility that the cysteine protease cathepsin B (CB) is a participant in the process of glial tumor cell invasion. To accomplish this, an immunohistochemical analysis was made of the localization of antibodies to CB in biopsies of five specimens of normal brain, 16 astrocytomas, 33 anaplastic astrocytomas, and 33 glioblastomas multiforme.
Staining was scored according to the percentage of positive cells and the intensity of the stain, graded from 0 to 3+. Staining for CB was not seen in any of five samples of normal brain except for occasional neuronal cell bodies and microglia. Only five (31%) of 16 astrocytomas showed a small percentage of positive cells (0.01%–3%) that were stained in a light, diffuse cytoplasmic pattern (1+). Twenty-nine (87.8%) of 33 anaplastic astrocytomas showed positive light, granular staining in 2% to 40% of cells. In anaplastic astrocytoma, the staining within a tumor was heterogeneous with intensities of 1+ (17%), 1+ to 2+ (29%), or 2+ (55%). In contrast, all 33 (100%) glioblastomas were positive in 10% to 90% of cells. The staining was present in a coarse, granular pattern with an intensity of 2+ (12%) or 3+ (88%). Tumor cells infiltrating into brain adjacent to malignant gliomas stained positively in 26 cases that could be evaluated for glioblastoma multiforme; these invading cells frequently followed penetrating blood vessels as typical “secondary structures of Scherer.” Moderate to intense CB staining associated with endothelial proliferation in high-grade tumors was also observed, especially in regions of tumor infiltration into adjacent normal brain. These results provide evidence consistent with the hypothesis that CB is functionally significant in the process of tumor invasion and angiogenesis in the clinical progression of the malignant phenotype in astrocytomas.
Experimental chronic compressive cervical myelopathy: effects of decompression
Authors: Harkey H. Louis , Al-Mefty Ossama , Marawi Isam , Peeler Dudley F. , Haines Duane E. , Alexander Lon F. 
Published: June 2009

✓ Twelve dogs developed a delayed onset of neurological abnormalities from chronic cervical cord compression that was characteristic of myelopathy. The animals were divided into two groups and matched according to degree of neurological deficit. Six animals underwent decompression through removal of the anteriorly placed compressive device. Throughout the experiment, serial neurological examinations and somatosensory evoked potential studies were performed on each animal. Spinal cord blood flow measurements were obtained during each surgical procedure and at sacrifice. Magnetic resonance images were obtained after compression and before sacrifice.
All animals in the decompressed group showed significant neurological improvement after decompression; no spontaneous improvement in neurological function was seen in the compressed group. On pathological examination, irreversible changes including large motor neuron loss, necrosis, and cavitation were seen in four of the animals in the decompressed group and five in the compressed group.
Cervical spondylotic myelopathy in humans is known to respond to decompression; this study provides further evidence that this animal model for chronic compressive cervical myelopathy accurately reflects the disease process seen in humans.
Familial aneurysmal subarachnoid hemorrhage: a community-based study
Authors: Schievink Wouter I. , Schaid Daniel J. , Michels Virginia V. , Piepgras David G. 
Published: June 2009

✓ The familial occurrence of intracranial aneurysms has been well described. However, intracranial aneurysms are not rare and the great majority of reported families consist of only two affected members. Therefore, the familial aggregation of intracranial aneurysms could be fortuitous. The authors investigated the familial occurrence of aneurysmal subarachnoid hemorrhage (SAH) in their community to determine whether family members of patients with a ruptured aneurysm are at an increased risk of developing an SAH.
All 81 patients from Rochester, Minnesota, who suffered an SAH between 1970 and 1989 from a proven aneurysmal rupture were identified, and they or their families were contacted and a family history was obtained. The number of expected SAHs among first-degree relatives was calculated using previously established age- and sex-specific incidence rates in the community of Rochester. Of the 81 index patients, 76 had complete follow up for family history. Fifteen (20%) of these 76 patients had a first- or second-degree relative with aneurysmal SAH. The number of observed first-degree relatives with aneurysmal SAH was 11, compared to an expected number of 2.66, giving a relative risk of 4.14 (95% confidence interval 2.06–7.40; p < 0.001).
In the authors' community, aneurysmal SAH was familial in one of five patients, and this familial aggregation was not fortuitous. The increase in familial risk of aneurysmal SAH is approximately fourfold among first-degree relatives.
Hydrocephalus associated with intramedullary low-grade gliomas
Authors: Cinalli Giuseppe , Sainte-Rose Christian , Lellouch-Tubiana Arielle , Sebag Guy , Renier Dominique , Pierre-Kahn Alain 
Published: June 2009

✓ Over the past 15 years, eight children affected by intramedullary low-grade gliomas associated with hydrocephalus were treated at l'Hôpital des Enfants Malades. In all cases the diagnosis of hydrocephalus was made prior to that of the spinal tumor. Neuroradiological examination of all patients revealed contrast enhancement of the intracranial subarachnoid spaces. In six cases this was progressive, suggesting subarachnoid spread of the tumor, which was confirmed in two cases by histological examination.
The authors analyzed 38 cases of intramedullary low-grade glioma associated with hydrocephalus that were reported in the literature. Fifteen of the cases had intracranial leptomeningeal seeding. Several hypotheses have been proposed to explain this unusual association, such as 1) increase in cerebrospinal fluid (CSF) viscosity because of elevated fluid protein content; 2) obliteration of the cisterna magna due to a rostral extension of the tumor; and 3) blockage of the spinal subarachnoid pathways of CSF resorption. Two other theories seem of particular interest. Bamford and Labadie suggested that the abnormal presence of fibrinogen in the CSF and its transformation into fibrin at the level of the basal cisterns and Pacchioni's granulation may alter CSF hydrodynamics. This mechanism alone is sufficient to induce hydrocephalus of the communicating type. In addition, as suggested by Maurice-Williams and Lucey, the resulting leptomeningeal fibrosis might predispose secondary implantation of neoplastic elements in the subarachnoid spaces of the intracranial compartment.
Loss of forebrain cholinergic neurons following fluid-percussion injury: implications for cognitive impairment in closed head injury
Authors: Schmidt Richard H. , Grady M. Sean 
Published: June 2009

✓ Disturbances in memory, concentration, and problem solving are common after even mild to moderate traumatic brain injury. Because these functions are mediated in part by forebrain cholinergic and catecholaminergic innervation, in this study the authors sought to determine if experimental concussive injury produces detectable morphological damage to these systems.
Fluid-percussion head injury, sufficient to cause a 13- to 14-minute loss of righting reflex, was produced in rats that had been anesthetized with halothane. Injury was delivered either at midline or 2 mm off midline and compared with appropriate sham-injured controls. After 11 to 15 days, the rat brains were stained in serial sections for choline acetyltransferase, tyrosine hydroxylase, dopamine β-hydroxylase, acetylcholinesterase, and nicotinamide adenine dinucleotide phosphate diaphorase. Cell counts were determined for the entire population of ventrobasal forebrain cholinergic cells. Midline injury produced a bilateral loss of cholinergic neurons averaging 36% in area Ch1 (medial septal nucleus), 45% in Ch2 (nucleus of the diagonal band of Broca), and 41% in Ch4 (nucleus basalis of Meynart), (p ≤ 0.05). Lateralized injury resulted in cholinergic neuron loss of similar magnitude ipsilaterally (p ≤ 0.05), but a smaller contralateral loss of between 11% and 28%. No loss of neurons was detected in the pontomesencephalic cholinergic groups Ch5 and Ch6. There was no visible effect of head injury on forebrain dopamine or noradrenergic innervation.
A significant and apparently selective loss of ventrobasal forebrain cholinergic neurons following brief concussive injury in rats is demonstrated in this study. This type of injury is known to produce significant disturbance in cognitive tasks linked to neocortical and hippocampal cholinergic function. It remains to be determined how this neuron loss occurs, whether it can be prevented with neuroprotective agents, how it affects innervation in target tissues, and whether it occurs in human victims of traumatic brain injury.
Genesis of a dural arteriovenous malformation in a rat model
Authors: Herman James M. , Spetzler Robert F. , Bederson Joshua B. , Kurbat James M. , Zabramski Joseph M. 
Published: June 2009

✓ A rat model was developed to determine the role of sinus thrombosis and elevated sinus pressures in the pathogenesis of dural arteriovenous malformations (AVMs) Five protocols were tested to compare various sinus pressures and thrombosis of a sinus: 1) Control I, sham operation (five animals); 2) Control II, occlusion of the right common carotid artery, the right external jugular vein, and the vein draining the left transverse sinus, as well as thrombosis of the sagittal sinus (10 animals); 3) arteriovenous fistula (AVF) I, anastomosis of the right common carotid artery to the external jugular vein causing retrograde flow through the transverse sinus (10 animals); 4) AVF II, anastomosis (as described in AVF I) and thrombosis of the sagittal sinus (12 animals); 5) AVF III, anastomosis (as described in AVF I) as well as thrombosis of the sagittal sinus and occlusion of the vein draining the transverse sinus on the left (12 animals). Mean arterial and sagittal sinus pressures were monitored and cerebral angiograms were obtained intraoperatively and again 90 days later. Afterward, the animals were sacrificed and their brains and dura were examined histologically.
Formation of a fistula resulted in a significant (p < 0.05) threefold increase in sagittal sinus pressure in the AVF II group and a significant (p < 0.05) sixfold increase in the AVF III group. Seven dural AVMs (three in the AVF II group and four in the AVF III group) were demonstrated angiographically and histologically. The seven malformations were located adjacent to a thrombosed sagittal sinus. All lesions were within the dura and sinus wall with direct thrombus—sinus wall connections demonstrated in four of the malformations. The other three lesions displayed arteriovenous connections within the sinus wall and dura. These data suggest the importance of not only sinus thrombosis but also sinus hypertension in the development of a dural AVM.
Repair of critical size rat calvarial defects using extracellular matrix protein gels
Authors: Sweeney Thomas M. , Opperman Lynne A. , Persing John A. , Ogle Roy C. 
Published: June 2009

✓ In this study the authors examined the capacity of gels of reconstituted basement membrane, laminin, and type I collagen to mediate repair of critical size defects in rat calvaria. Although autografts are widely used to repair bone defects caused by trauma or surgical treatment of congenital malformations, neoplasms, and infections, an adequate quantity of graft is not always available. Allogenic bone is readily available, but its use is associated with an increased incidence of nonunion, fatigue fracture, and rejection. Biologically active, purified components of basement membranes, which have been shown to promote osteogenic differentiation and angiogenesisin vitroand type I collagen (the major constituent of bone extracellular matrix) can be formed into native isotonic space-filling gels.In this study critical size calvarial defects were created in retired male Sprague-Dawley rats. Thirty-six animals were divided into seven groups. Group 1 (control) received no treatment for the defects. Group 2 animals were implanted with methylcellulose. Groups 3, 4, 5, and 6 were implanted with gels of type I collagen, reconstituted basement membrane, or laminin, respectively. The last group of three animals (Group 7) was implanted with 100 µg of type I collagen gels (identical to Group 3) and sacrificed at 20 weeks following a single CT scan to determine if complete healing could be obtained with this method given sufficient time. Except for rats in the type I collagen group that was evaluated by multiple computerized tomography (CT) scans biweekly from 2 to 12 weeks, bone repair was evaluated using CT at 12 weeks. Healing was quantified using three-dimensional reconstruction of CT. Following the final CT scan in each experimental group, animals were sacrificed, and a sample of tissues was evaluated by conventional histology. Animals treated with type I collagen gels showed 87.5% repair of the area of the defects at 12 weeks and 92.5% repair by 20 weeks. Increasing the gel volume 1.5 × accelerated complete repair to 3 months. Murine-reconstituted basement membrane and laminin gels induced 55.5% and 46.3% repair, respectively, at 3 months. In untreated control animals 7% repair of the area of the defects showed at 3 months. Histological analysis confirmed new bone formation in partial and completely healed defects. Bioengineered native collagen gels may have wide applicability for bone repair as an alternative bone graft material alone, in combination with autograft or marrow aspirate, or as a delivery system for osteogenic growth factors.