bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinical presentation and management of giant anterior communicating artery region aneurysms
Authors: Lownie Stephen P. , Drake Charles G. , Peerless Sydney J. , Ferguson Gary G. , Pelz David M. 
Published: May 2009

Object. The authors reviewed their 20-year experience with giant anterior communicating artery aneurysms to correlate aneurysm size with clinical presentation and to analyze treatment methods.Methods. In 18 patients, visual and cognitive impairment were quantitated and clinical outcome was categorized according to the Rankin scale. Statistical analysis was performed using Fisher's exact test.Conclusions. At least 3.5 cm of aneurysm mass effect was required to produce dementia in the patient (p = 0.0004). Dementia was usually caused by direct brain compression by the aneurysm rather than by hydrocephalus. Optic apparatus compression occurred with smaller aneurysms (2.7–3.2 cm) when they pointed inferiorly.Aneurysm neck clipping was possible in half of the cases. Special techniques, including temporary clipping, evacuation of intraluminal thrombus, tandem and/or fenestrated clipping, and clip reconstruction were often required. Occlusion of or injury to the anterior cerebral artery (ACA) was the main cause of poor outcome or death.Proximal ACA occlusion, even of dominant A1 segments with small or no contralateral A1 artery, was an effective treatment alternative and was well tolerated as a result of excellent leptomeningeal collateral circulation.
An implantable guide-screw system for brain tumor studies in small animals
Authors: Lal Sumeer , Lacroix Michel , Tofilon Philip , Fuller Gregory N. , Sawaya Raymond , Lang Frederick F. 
Published: May 2009

Object. To overcome the problems associated with using stereotactic techniques to establish intracranial xenografts in nude mice and to treat engrafted tumors with intratumoral therapies (such as gene or viral therapies), the authors developed an implantable guide-screw system. In this study, they describe the guide-screw system, its method of implantation, and their experience with establishing xenografts and delivering intratumoral therapy.Methods. The system consists of a 2.6-mm guide screw with a central 0.5-mm diameter hole that accepts the 26-gauge needle of a Hamilton syringe. The screw is implanted into a small drill hole made 2.5 mm lateral and 1 mm anterior to the bregma. A stylet is used to cap the screw between treatments. Tumor cells or therapeutic agents are injected in a freehand fashion by using a Hamilton syringe and a 26-gauge needle fitted with a cuff to determine the depth of injection. To test this system, guide screws were successfully implanted in 44 (98%) of 45 nude mice. After 1 to 2 weeks of recovery, 38 mice were inoculated with U87MG cells and killed 5 days later. On histological studies in 37 (97%) of these animals, xenografts were evident within the caudate nucleus (mean diameter 2.5 mm). To determine whether injections into the center of an established xenograft could be reproducibly achieved with the guide-screw system, an adenovirus vector containing the β-galactosidase gene was injected 3 days after cell implantation in 15 of the mice. All of these animals demonstrated transduced cells within the tumor. To demonstrate that engrafted animals have a uniform survival time that is indicative of reproducible tumor growth, the survival of six mice was assessed after engraftment with U87MG cells. All six animals died within 28 to 35 days.Conclusions. The guide-screw system allows a large number of animals to be rapidly and reproducibly engrafted and for intratumoral treatments to be accurately delivered into established xenografts.
Long-term follow up of progesterone receptor status in benign meningioma: a prognostic indicator of recurrence?
Authors: Fewings Paul E. , Battersby Robert D. E. , Timperley Walter R. 
Published: May 2009

Object. A long-term prospective analysis of patients with benign meningioma was undertaken to determine whether progesterone receptor (PR) status of the excised tumor has any influence on recurrence.Methods. Between 1983 and 1985, a total of 62 meningiomas in 53 patients (age range 19–79 years, mean age 55.6 years) were studied for clinical, histological, and pathological characteristics, including hormone receptor status and DNA features. Progesterone receptor status was quantified by cryostat section assay, and then factors affecting recurrence were analyzed. During 1997 all case records were reviewed to determine whether tumor had recurred in any patient, and PR status was correlated with tumor recurrence.Of the 62 tumors, 60 were benign, and of the benign tumors 29 (48%) were PR positive. Patients harboring 14 of the 60 benign tumors were lost to follow up. Of the 46 tumors included in the final analysis, 13 were recurrent (all within 5 years) and 33 were nonrecurrent. Of the 33 nonrecurrent tumors, 14 had not recurred 5 to 10 years postresection and 19 had not recurred after more than 10 years. Chi-square analysis of the results did not show an association between recurrence and patient's sex, extent of resection, histological subtype, or tumor site but did show an association between recurrence and PR negativity (p = 0.013).Conclusions. The results indicate that benign meningiomas that are PR positive are less likely to recur, a finding that has prognostic and therapeutic implications.
Locomotion and proliferation of glioblastoma cells in vitro: statistical evaluation of videomicroscopic observations
Authors: Hegedüs Balás , Czirók András , Fazekas Ilona , Bábel Tamás , Madarász Emília , Vicsek Tamás 
Published: May 2009

Object. The motility and doubling of human glioblastoma cells were investigated by means of statistical evaluation of large sets of data obtained using computer-aided videomicroscopy.Methods. Data were obtained on cells in four established glioblastoma cell lines and also on primary tumor cells cultured from fresh surgical samples. Growth rates and cell cycle times were measured in individual microscopic fields. The averages of cell cycle time and the duplication time for the recorded cell populations were 26.2 ± 5.6 hours and 38 ± 4 hours, respectively. With these parameters, no significant differences among the cell lines were revealed. Also, there was no correlation in the cell cycle time of a parent cell and its progeny in any of the cultures.Statistical analysis of cell locomotion revealed an exponential distribution of cell velocities and strong fluctuations in individual cell velocities across time. The average velocity values ranged from 4.2 to 27.9 µm/hour. In spite of the uniform histopathological classification of the four tumors, each cell line produced by these tumors displayed distinct velocity distribution profiles and characteristic average velocity values. A comparison of recently established primary cultures with cell lines that had propagated multiple times indicated that cells derived from different tumors sustain their characteristic locomotor activity after several passages.Conclusions. It can be inferred from the data that statistical evaluation of physical parameters of cell locomotion can provide additional tools for tumor diagnosis.
Intracranial hypotension without meningeal enhancement on magnetic resonance imaging
Authors: Schievink Wouter I. , Tourje James 
Published: May 2009

✓ Meningeal enhancement on magnetic resonance (MR) imaging is considered the hallmark radiological feature of intracranial hypotension. The authors report on a patient who exhibited progressively symptomatic intracranial hypotension due to a lumbar cerebrospinal fluid (CSF) leak, but in whom MR imaging demonstrated no pachymeningeal enhancement.This 24-year-old man presented with a 6-week history of progressive orthostatic headaches that were associated with photo- and phonophobia. Four weeks before the onset of the headaches, the patient had undergone a lumbar laminectomy. Brain MR images revealed subdural fluid collections and brain sagging; however, meningeal enhancement was not present. Myelography demonstrated a CSF leak at the site of the laminectomy. At surgery, a large dural tear was repaired. The patient recovered well from the surgery, with complete resolution of his headaches.The absence of meningeal enhancement on MR imaging does not exclude a diagnosis of symptomatic intracranial hypotension.
Tethered cord syndrome in children with anorectal malformations
Authors: Muthukumar Natarajan , Subramaniam Bhuvaneswari , Gnanaseelan Thangaraj , Rathinam Ramesh , Thiruthavadoss Appaswamy 
Published: May 2009

Object. Anorectal malformations are known to be associated with neurological deficits, which may contribute to the disability suffered by patients with these malformations. This study was undertaken to determine the incidence and pattern of sacral abnormalities in children with anorectal malformations, the incidence and nature of the neurological deficits, and the incidence and nature of operable intraspinal abnormalities in patients with this condition.Methods. Neurological evaluation was performed in 81 children with anorectal malformations. Plain x-ray films were obtained to identify the presence of sacral abnormalities. The patients with neurological deficits were evaluated for the presence of operable intraspinal anomalies, and when such anomalies were identified, correction of the same was undertaken. In 21% of these children radiographic evidence of sacral abnormalities was shown. Fifteen percent of patients harbored neurological deficits, and 10% harbored operable intraspinal anomalies. In addition, one patient had split notochord syndrome. Patients with operable intraspinal anomalies underwent surgical correction, with resultant neurological improvement.Conclusions. Bone abnormalities of the sacrum, neurological deficits, and operable intraspinal lesions are not uncommon in children with anorectal malformations. Because the neurological deficits can contribute to the disability suffered by these individuals, we recommend routine screening of patients with anorectal malformations and neurological deficits and/or sacral abnormalities for the early identification and treatment of potentially correctable intraspinal lesions.
Fibroblast growth factor receptor 3 mutation in nonsyndromic coronal synostosis: clinical spectrum, prevalence, and surgical outcome
Authors: Renier Dominique , El Ghouzzi Vincent , Bonaventure Jacky , Le Merrer Martine , Lajeunie Elizabeth 
Published: May 2009

Object. A recurrent point mutation in the fibroblast growth factor receptor 3 gene that converts proline 250 into arginine has been reported recently in cases of apparently nonsyndromic coronal craniosynostosis. The goal of the present study was to examine the phenotype of patients in whom this mutation was present, to determine the prevalence of the condition, and to assess the functional and the morphological outcome of the surgically treated patients.Methods. A DNA analysis was performed in 103 children suffering from apparently isolated coronal synostosis, 41 of whom had bilateral and 62 of whom had unilateral disease. There were 31 boys and 72 girls in the study group. Sixty cases were sporadic and 43 were familial; the 43 familial cases arose in 33 unrelated families. The mutation was found in seven (12%) of 60 sporadic cases and in 24 (73%) of the 33 families. The functional and morphological results were assessed in all surgically treated patients who had at least 1 year of follow up and who were at least 3 years of age at the time of assessment. A comparison was made between patients with the mutation and those without.Conclusions. The most typical presentation was seen in girls and consisted of a bicoronal synostosis resulting in a severe brachycephaly associated with mild hypertelorism and marked bulging of the temporal fossae, which resulted in a huge enlargement of the upper part of the face. The most frequently associated extracranial anomaly was brachydactyly, identified either clinically or radiologically. Based on the proportion of bilateral and unilateral coronal synostoses, the present data indicate that the mutation is associated with more severe cases and that girls with the mutation are more severely affected than boys. The functional and morphological results were worse in patients in whom the mutation was present as compared with those in whom it was not.
Neuroscience education of undergraduate medical students. Part I: role of neurosurgeons as educators
Authors: Resnick Daniel K. 
Published: May 2009

Object. Economic, demographic, and political pressures have mandated that medical schools increase the number of primary care physicians. The goal of this study was to determine the nature of the average medical student's exposure to neurosurgical issues.Methods. Surveys were sent to every neurosurgical program director in the United States and to the dean of every medical school in North America, querying the extent of neurosurgical involvement in medical student education. Specifically, the respondents were asked how medical students were educated about the management of low-back pain and radiculopathy, carotid artery disease, head and spine trauma, and headache.Survey results were obtained from 65 (67%) of 97 neurosurgery program directors and from 57 (40%) of 143 medical school deans. Only one program in North America reported having a required neurosurgical rotation for all medical students, and just over 50% (29 of 57 deans and 34 of 65 program directors) reported that neurosurgery was an option in a required neuroscience or surgical subspecialty course. Neurosurgeons were not listed among the top three sources for medical student education in the topics of low-back pain and radiculopathy or carotid artery disease. Neurosurgeons were the most frequently cited source of education regarding head and spinal injuries, despite the fact that the majority of medical schools do not have any required medical student exposure to neurosurgery.Conclusions. With rare exceptions, neurosurgeons are not significantly involved in the education of medical students concerning the management of common neurosurgical issues. As a result, most emerging primary care physicians are taught about these issues by other specialists or not at all. The implications of this situation are discussed.
Neuroscience education of undergraduate medical students. Part II: outcome improvement
Authors: Resnick Daniel K. , Ramirez Lincoln F. 
Published: May 2009

Object. Because of political and economic pressures, primary care physicians are now charged with greater responsibility for the care of patients with disease processes definitively managed by neurosurgeons. The goal of this study was to establish the feasibility and efficacy of a neurosurgical curriculum designed to teach future primary care physicians about these diseases.Methods. A compact, seven-lecture curriculum was developed to teach 3rd-year medical students about degenerative spine disease, stroke, tumor- and hydrocephalus-related raised intracranial pressure, head and spine injury, and subarachnoid hemorrhage. This curriculum was given as part of a 6-week pilot course that included neurology, neurosurgery, ophthalmology, and rehabilitation medicine components. This course was administered to two groups of 18 medical students, and an examination was administered at the end of the pilot course. The same examination was administered to an additional 19 students immediately after their completion of the neurology course currently required.Students enrolled in the pilot neuroscience course performed significantly better (p < 0.001) on the examination than those who had completed the standard neurology course. Striking improvements were noted in the recognition and management of head injury, hydrocephalus, and radiculopathy.Conclusions. Inclusion of a short neurosurgery-related curriculum in a combined neuroscience course significantly improved student performance on an examination focusing on the recognition and management of common neurosurgical disorders. Because primary care physicians are responsible for the initial recognition and management of these disorders, the knowledge gained may lead to improved patient care.
Neuroprotection by the stable nitroxide Tempol during reperfusion in a rat model of transient focal ischemia
Authors: Rak Ramin , Chao Daniel L. , Pluta Ryszard M. , Mitchell James B. , Oldfield Edward H. , Watson Joe C. 
Published: May 2009

Object. The use of thrombolytic agents in the treatment of stroke has yielded surprisingly modest success, possibly because of reperfusion injury mediated by reactive oxygen species (ROS). Therefore, scavenging ROS may be of therapeutic value in the treatment of stroke. Nitroxides are low-weight superoxide dismutase mimics, which allows them to act as cell-permeable antioxidants. In this study the nitroxide 4-hydroxy-2,2,6,6,-tetramethylpiperidine-1-oxyl (Tempol) is investigated to determine its ability to reduce reperfusion injury.Methods. Male Sprague—Dawley rats weighing between 280 g and 350 g underwent middle cerebral artery occlusion with an intraluminal suture for 60 minutes. Regional cerebral blood flow, blood pressure, cerebral temperature, and rectal temperature were monitored during the procedure. After reperfusion, the animals were randomized to groups receiving blinded intravenous administration of either Tempol (10 mg/kg; eight animals) or vehicle (eight animals) over the first 20 minutes of reperfusion (Study I). In a second study to determine dose dependency, animals were randomized to groups receiving Tempol (20 mg/kg; eight animals), low-dose Tempol (5 mg/kg; eight animals), or vehicle (eight animals; Study II). The rats were killed after 4 hours of reperfusion, and brain sections were stained with 2,3,5 triphenyltetrazolium chloride. Infarct volumes were measured using digital imaging.Animals receiving Tempol had significantly reduced infarct volumes at doses of 20 mg/kg and 10 mg/kg compared with controls (49.01 ± 18.22% reduction [p = 0.003] and 47.47 ± 34.57 [p = 0.02], respectively). No significant differences in the physiological variables measured were observed between groups.Conclusions. Tempol provides significant neuroprotection after reperfusion in a rat model of transient focal ischemia. These results support the importance of ROS in reperfusion injury and encourage further study of this molecule as a therapeutic agent following thrombolysis.
Genetic reflection of glioblastoma biopsy material in xenografts: characterization of 11 glioblastoma xenograft lines by comparative genomic hybridization
Authors: Jeuken Judith W. M. , Sprenger Sandra H. E. , Wesseling Pieter , Bernsen Hans J. J. A. , Suijkerbuijk Ron F. , Roelofs Femke , Macville Merryn V. E. , Gilhuis H. Jacobus , van Overbeeke Jacobus J. , Boerman Rudolf H. 
Published: May 2009

Object. Human tumors implanted as subcutaneous xenografts in nude mice are widely used for the study of tumor biology and therapy. Validation of these models requires knowledge of the genetic makeup of the xenografts. The aim of this study was to establish whether chromosomal imbalances in 11 xenograft lines derived from human glioblastomas multiforme (x-GBMs) are similar to those found in GBM biopsy samples. The authors also studied genetic stability during serial passaging of three xenograft lines.Methods. Chromosomal imbalances in x-GBMs were detected using comparative genomic hybridization (CGH). The authors compared the CGH results in x-GBMs with those in the original GBMs (o-GBMs) that were used to establish three of the xenograft lines and with the GBM biopsy results reported in the literature (l-GBMs). In three xenograft lines two different passages were analyzed.Conclusions. The results show that the chromosomal imbalances in x-GBMs are similar to those in o-GBMs and l-GBMs, indicating that the GBM xenograft lines used were valid models from a genetic point of view. The CGH analysis of two different passages of three xenograft lines indicates that x-GBMs (like l-GBMs) show intratumoral genetic heterogeneity and do not acquire chromosomal imbalances as a result of serial passaging.
Promotion of survival and regeneration of nigral dopamine neurons in a rat model of Parkinson's disease after implantation of embryonal carcinoma—derived neurons genetically engineered to produce glial cell line—derived neurotrophic factor
Authors: Nakao Naoyuki , Yokote Hideyuki , Nakai Kunio , Itakura Toru 
Published: May 2009

Object. The P19 embryonal carcinoma—derived cell line consists of undifferentiated multipotential cells, which irreversibly differentiate into mature neurons after exposure to retinoic acid (RA). In the present study, the authors genetically engineered P19 cells to produce glial cell line—derived neurotrophic factor (GDNF), and grafted the cells in a rat model that had been rendered parkinsonian.Methods. Undifferentiated P19 cells were grown in vitro and transduced with GDNF complementary DNA. The level of GDNF released from the transduced cells was measured using an enzyme-linked immunosorbent assay, and its neurotrophic activities were assessed by testing the effects on rat embryonic dopamine (DA) neurons in culture. After having been exposed to RA for 48 hours and allowed to differentiate into postmitotic neurons, the GDNF gene—transduced cells were implanted into the midbrain of immunosuppressed rats. A unilateral nigrostriatal lesion was then induced by intrastriatal infusions of 6-hydroxydopamine. Immunohistochemical analyses performed 4 weeks postgrafting revealed that the GDNF-producing cells expressed several neuronal markers without evidence of overgrowth. The grafts expressed GDNF protein and prevented the death of nigral DA neurons. Furthermore, the GDNF-producing cells implanted 4 weeks after nigrostriatal lesions restored the expression of tyrosine hydroxylase in injured DA neurons and induced their dendritic sprouting.Conclusions. The results indicate that the P19 cell line transduced with the GDNF gene can stably secrete functional levels of GDNF, even after being converted to postmitotic neurons. Because it is has been established that GDNF exerts trophic effects on DA neurons, the means currently used to deliver GDNF into the brain could be a viable strategy to prevent the death of nigral DA neurons in cases of Parkinson's disease.