bluuebunny/crossref_metadata_2025_split huggingface dataset:
Total removal of craniopharyngiomas
Authors: Yaşargil M. Gazi , Curcic Marijan , Kis Mirjana , Siegenthaler Gertrud , Teddy Peter J. , Roth Peter 
Published: May 2009

✓ The clinical features, perioperative course, and postoperative outcomes of 144 patients who underwent microsurgical resection of craniopharyngioma were reviewed. Overall, 90% of the tumors were completely resected and 7% recurred. Evaluation of those patients who underwent primary resection revealed much better results. The operative techniques and approaches are reviewed in detail. The results of this series suggest that primary total removal of craniopharyngiomas yields the best long-term outcome for the patient.
Experience has shown that the larger the tumor the greater will be the damage, both preoperatively and intraoperatively, to vital intracranial structures. Consequently, early diagnosis, at a stage when the tumor is still small, improves the chances of accomplishing complete removal and of achieving good operative results. The early diagnosis of craniopharyngioma, before it can produce devastating neurological defects, continues to be the principal goal of our medical and pediatric colleagues.
Response of malignant glioma cell lines to activation and inhibition of protein kinase C-mediated pathways
Authors: Pollack Ian F. , Randall Margaret S. , Kristofik Matthew P. , Kelly Robert H. , Selker Robert G. , Vertosick Frank T. 
Published: May 2009

✓ To evaluate the role of protein kinase C-mediated pathways in the proliferation of malignant gliomas, this study examined the effect of a protein kinase C (PKC)-activating phorbol ester (12-O-tetradecanoyl-13-phorbol acetate or TPA) and a protein kinase C inhibitor (polymyxin B) on deoxyribonucleic acid (DNA) synthesis of malignant glioma cells in vitro. A serum-free chemically defined medium, MCDB 105, was employed for all studies. Two established human malignant glioma cell lines (T98G and U138), two rat glioma lines (9L and C6), and two low-passage human glioma lines (obtained from surgical specimens) were studied. With the exception of the C6 line, all tumors responded in a dose-dependent fashion to nanomolar concentrations of TPA with a median effective dose that varied from 0.5 ng/ml for the U138 glioma to 1 ng/ml for the T98G glioma. At optimal concentrations (5 to 10 ng/ml), TPA produced a two- to five-fold increase in the rate of DNA synthesis (p < 0.05) as assessed by incorporation of 3H-thymidine. However, TPA had no additive effect on the mitogenic response produced by epidermal growth factor (EGF) or platelet-derived growth factor (PDGF). Inhibition of PKC using the antibiotic polymyxin B (20 µg/ml) abolished the TPA-induced mitogenic response in the five responsive lines tested. In two tumors (U138 and 9L), polymyxin B also eliminated EGF-, PDGF-, and serum-induced DNA synthesis as well as abolishing baseline DNA synthesis. These cells remained viable, however, as assessed by trypan blue exclusion; after removal of polymyxin B from the medium, they were able to resume DNA synthesis in response to TPA and serum. In the three other tumors (T98G and the two low-passage human glioma lines), growth factor-induced and serum-induced DNA synthesis were inhibited by approximately 25% to 85%.
It is concluded that PKC-mediated pathways affect DNA synthesis in the human malignant glial tumors studied. The response of the glioma cells to TPA is similar to the responses seen in fetal astrocytes, but differs significantly from those reported for normal adult glial cultures. Because the response of the 9L glioma to TPA is similar to the responses seen in the human tumors, the 9L rat glioma model may prove useful for examining the role of PKC-mediated pathways in controlling glioma growth in vivo.
Surgical treatment of unruptured aneurysms of the posterior circulation
Authors: Rice Beverly J. , Peerless Sydney J. , Drake Charles G. 
Published: May 2009

✓ With the ever-increasing number of intact aneurysms revealed by modern imaging, the options for their management are assuming great importance. While some knowledge has emerged as to their natural history and the results of surgical treatment of those in the anterior circulation, little information has been published concerning unruptured aneurysms arising from the posterior circulation. The authors report their experience since 1971 with 167 patients operated on for 179 unruptured vertebrobasilar aneurysms up to 25 mm in diameter. Overall, 160 aneurysms were treated by direct clip obliteration, while 19 were managed by alternative methods. Fifty-three patients (32%) had solitary aneurysms and the other 114 patients (68%) had multiple aneurysms or an associated arteriovenous malformation, which were commonly treated concurrently. Many of these coexisting vascular anomalies had ruptured in the recent or remote past, adding to the complexity of management and interpretation of specific surgical results related to the intact posterior circulation aneurysm.
There were 78 documented postoperative complications including 23 systemic complications, seven postoperative hematomas, six brain injuries from retraction, five cases of aseptic meningitis, three instances of seizures, three wound infections, and three patients with hydrocephalus. Multiple complications occurred in 23 patients. Seventy-one of the patients with these untoward events recovered, without disability, with time or treatment.
There were only six poor results and one death in the series, resulting in a 4.2% combined morbidity/mortality rate. However, since two of these poor outcomes and the single death were attributable to a coexisting aneurysm, the actual surgical morbidity related specifically to the posterior circulation aneurysm was only 2.4%. This experience suggests that non-giant, intact vertebrobasilar aneurysms can be obliterated surgically at a very low risk, and this treatment should eliminate the greater lifetime risk related to an unsecured aneurysm.
CT-guided stereotactic fibrinolysis of spontaneous and hypertensive cerebellar hemorrhage: long-term results
Authors: Mohadjer Mohsen , Eggert Rudolf , May Johannes , Mayfrank Lothar 
Published: May 2009

✓ The surgical indication for spontaneous cerebellar hemorrhage is not as controversial as the operative management of intracranial hemorrhage. Timing of the operation is crucial: intervening too early can produce an additional strain on the patient and an increased risk, while waiting too long to evacuate the hematoma can be fatal. This dilemma may be a factor in the relatively high mortality and morbidity rates following both operative and conservative treatment that have been reported in the literature (42.5% and 30%, respectively).
In long-term studies on 14 patients, the authors have shown that stereotactic puncture and fibrinolysis for cerebellar hemorrhage is a valuable alternative to treatments used currently. The method consists of computerized tomography (CT)-guided stereotactic puncture and partial evacuation of the hematoma. After fibrinolysis with urokinase, the residual hematoma can be completely evacuated via a catheter introduced into the cavity of the hematoma. Only one of the 14 patients died in the direct postoperative phase; the remaining patients were enjoying a good to very good quality of life 6 months after the acute event. Two patients subsequently died as a result of pneumonia and cerebral infarction, respectively; both conditions were unrelated to the hemorrhage. The authors conclude that the CT-guided stereotactic method is simple, effective, and safe, and can be applied to patients of any age.
Correlation of in vitro bromodeoxyuridine labeling index and DNA aneuploidy with survival or recurrence in brain-tumor patients
Authors: Nishizaki Takafumi , Orita Tetsuji , Kajiwara Koji , Ikeda Norio , Ohshita Noboru , Nakayama Hisato , Furutani Yasuhiro , Ikeyama Yukihide , Akimura Tatsuo , Kamiryo Toshifumi , Ito Haruhide 
Published: May 2009

✓ There are no previous reports correlating the in vitro bromodeoxyuridine (BUdR) labeling index (LI) with the clinical outcome in patients with brain tumors. The reliability of the LI as a predictor of patient survival or recurrence was examined in this study of 66 human brain tumors (19 gliomas, 18 meningiomas, and 29 others). Anti-BUdR staining was performed on surgically extirpated tumor tissue that had been treated with BUdR as previously described. Correlation of the BUdR LI with patient survival or tumor recurrence rate was carried out by the method of Kaplan and Meier. Deoxyribonucleic acid (DNA) aneuploidy was estimated in 52 cases.
The results of this study indicate that BUdR LI values correlated well with the clinical course of patients with brain tumor. In comparison with patients with higher LI's, there was both a significantly higher survival rate for tumors other than meningiomas and a higher recurrence-free rate for meningiomas in patients with LI's of less than 4% and 1%, respectively. Although there was a tendency for patients without tumor aneuploidy to show better survival data than the others, no statistical difference was observed. These results suggest that the in vitro BUdR labeling method is reliable for prediction of a patient's prognosis, whereas prognosis on the basis of DNA aneuploidy alone is uncertain.
Cerebral venous malformations
Authors: Rigamonti Daniele , Spetzler Robert F. , Medina Marjorie , Rigamonti Karen , Geckle David S. , Pappas Conrad 
Published: May 2009

✓ Although cerebral venous malformations have been reported to cause epilepsy, progressive neurological deficits, and hemorrhage, their clinical significance remains controversial. In an attempt to clarify the natural history of the lesion and suggest an appropriate management strategy, the authors review their experience with 30 patients. In four patients with cerebellar venous angioma, an acute episode of ataxia was documented. The coexistence of a cavernous malformation was pathologically confirmed in the two patients who underwent surgery for bleeding presumed caused by the venous angioma. Infarction was shown in two patients and a tumor in two others. Follow-up periods ranged between 18 and 104 months, with only five patients symptomatic at the time of this report. Rebleeding had not occurred, nor had acute episodes of neurological dysfunction been documented.
This clinical experience suggests that a venous malformation is frequently associated with other, more symptomatic conditions and is often erroneously identified as the source of the symptoms. Because the nature of the relationship between the venous malformation and the allied conditions remains ambiguous, it is recommended that patients harboring a “symptomatic” venous malformation undergo high-field magnetic resonance imaging to rule out underlying pathology, and that any such pathology be treated independently of the venous malformation.
A comparative study on ventriculographic and computerized tomography-guided determinations of brain targets in functional stereotaxis
Authors: Hariz Marwan I. , Bergenheim A. Tommy 
Published: May 2009

✓ Thalamic, pallidal, and hypothalamic targets were determined in 16 patients by a stereotactic computerized tomography (CT) study using a noninvasive technique with Laitinen's Stereoadapter. At surgery, the Stereoadapter was remounted to the head and the stereotactic CT coordinates were transferred to the Stereoguide without radiography. Air ventriculography was then carried out. The positions of the anterior and posterior commissures (AC and PC), the length of the intercommissural (IC) line, the width of the third ventricle, and the stereotactic coordinates of the target were measured on the ventriculograms and compared to the stereotactic CT measurements. The study showed that the width of the third ventricle was significantly larger on the ventriculograms than on the stereotactic CT scans, whereas the length of the IC line was not significantly different. The differences in the coordinates of the target and of the AC and PC were statistically significant only for the anteroposterior (y) coordinate. Both commissures as well as the surgical target lay, on average, 1.0 mm more anteriorly on the ventriculograms than on the stereotactic CT study.
It is concluded that air ventriculography may cause slight anterior displacement of the midbrain structures. The surgical coordinates of the targets based on the stereotactic CT study with the Stereoadapter were on average as accurate as those obtained with ventriculography; therefore, ventriculography may become superfluous in functional stereotaxis.
Transcranial Doppler ultrasound studies of cerebral autoregulation and subarachnoid hemorrhage in the rabbit
Authors: Nelson Richard J. , Perry Sheila , Hames Tony K. , Pickard John D. 
Published: May 2009

✓ The authors describe a method for Doppler ultrasound recording of flow velocity in the basilar artery of normal rabbits and rabbits with experimental subarachnoid hemorrhage (SAH). With this transcranial Doppler (TCD) model, clinical assumptions regarding flow velocity/cerebral blood flow (CBF) relationships, autoregulatory responses, and Doppler spectral waveform analysis can be tested under controlled conditions and compared with established methods of CBF measurement (hydrogen clearance).
The time course of changes in flow velocity following SAH (cerebral vasospasm) is successfully demonstrated using the experimental TCD method. There are significant differences in the flow velocity and CBF responses to hypercapnia, hypocapnia, and trimethaphan-induced hypotension which indicate that TCD cannot be considered a simple alternative to CBF measurement for the study of cerebrovascular reactivity and cerebral autoregulation.
Magnetic resonance imaging contrast agents: theory and application to the central nervous system
Authors: Bronen Richard A. , Sze Gordon 
Published: May 2009

✓ The theoretical aspects of magnetic resonance (MR) imaging contrast agents are reviewed, and their current applications to the central nervous system (CNS) and their future applications are discussed. Profound differences exist between contrast agents used for MR imaging and computerized tomography (CT). In MR imaging, the contrast agents are not imaged directly but rather act on adjacent protons to shorten T1 and T2 relaxation times. This in turn results in signal intensity changes. The lanthanide metal, gadolinium, in the form of gadopentetate dimeglumine, has been found to be both safe and efficacious as the only currently approved contrast agent for MR imaging.
Magnetic resonance imaging revolutionized the detection and treatment of disease affecting the brain and spine. Initially, it was thought that signal characteristics on MR imaging would allow differentiation of specific pathology. It was soon found that MR studies were able to detect more abnormalities but were less able to characterize them. The recent development of contrast agents for MR imaging has allowed this modality to surpass CT for the evaluation of most CNS lesions.
At present, contrast-enhanced MR imaging is generally accepted as the study of choice for evaluating acoustic neurinomas, pituitary lesions, meningeal disease, primary and secondary brain tumors, active multiple sclerosis, intradural spinal neoplasms, intramedullary spinal disease, and postoperative states in both the spine and brain. Even when contrast-enhanced CT can detect the same abnormalities, evaluation of the lesions in multiple planes on MR imaging can sometimes yield invaluable information, especially prior to surgery. Future developments of contrast material for MR imaging include non-gadolinium compounds, intrathecal contrast media, cerebral blood flow and volume evaluation, and, possibly, antibody-labeled contrast agents.
Clinoidal meningiomas
Authors: Al-Mefty Ossama 
Published: May 2009

✓ Anterior clinoidal meningiomas are frequently grouped with suprasellar or sphenoid ridge meningiomas, masking their notorious association with a high mortality and morbidity rate, failure of total removal, and recurrence. To avoid injury to encased cerebral vessels, most surgeons are content with subtotal removal. Without total removal, however, recurrence is expected. Recent advances in cranial-base exposure and cavernous sinus surgery have facilitated radical total removal.
The author reports 24 cases operated on with vigorous attempts at total removal of the tumor with involved dura and bone. This experience has distinguished three groups (I, II, and III) which influence surgical difficulties, the success of total removal, and outcome. These subgroups relate to the presence of interfacing arachnoid membranes between the tumor and cerebral vessels. The presence or absence of arachnoid membranes depends on the origin of the tumor and its relation to the naked segment of carotid artery lying outside the carotid cistern. Total removal was impossible in the three patients in Group I, with postoperative death occurring in one patient and hemiplegia in another. Total removal was achieved in 18 of the 19 patients in Group II, with one death from pulmonary embolism. In the two patients in Group III, total removal without complications was easily achieved.
Motility factor produced by malignant glioma cells: role in tumor invasion
Authors: Ohnishi Takanori , Arita Norio , Hayakawa Toru , Izumoto Shuichi , Taki Takuyu , Yamamoto Hiroshi 
Published: May 2009

✓ To better understand the cellular mechanism of tumor invasion, the production of a cell motility-stimulating factor by malignant glioma cells was studied in vitro. Serum-free conditioned media from cultures of rat C6 and human T98G cell lines contained a factor that stimulated the locomotion of the producer cells. This factor was termed the “glioma-derived motility factor.” The glioma-derived motility factor is a heat-labile protein with a molecular weight greater than 10 kD and has relative stability to acid. The factor showed not only chemotactic activity but also chemokinetic (stimulated random locomotion) activity in the two types of glioma cells studied. Although glioma-derived motility factors in conditioned media obtained from two different cell origins are likely to be the same, chemokinetic migration of T98G cells to their conditioned medium was much stronger than that of C6 cells to theirs.
Coincubation of cells with cytochalasin B, which disrupts the assembly of cellular actin microfilaments, almost completely inhibited the cell migration stimulated by glioma-derived motility factor. Cytochalasin B also induced marked alterations in cell morphology, including cell retraction and arborization, while the drug did not affect cell attachment to culture dishes. These results indicate that glioma cells produce a motility factor which may play a role particularly when tumor cells are detached and migrate away from the original tumor mass, thus promoting tumor invasion. Also, glioma cell migration stimulated by the motility factor requires the normal organization of cytoskeletons such as actin microfilaments.
Cerebrovascular and metabolic effects on the rat brain of focal Nd:YAG laser irradiation
Authors: Kiessling Marika , Herchenhan Eberhard , Eggert Hans R. 
Published: May 2009

✓ To investigate the effects of focal neodymium:yttrium-aluminum-garnet (Nd:YAG) laser irradiation (λ = 1060 nm) on regional cerebral blood flow, cerebral protein synthesis, and blood-brain barrier permeability, the parietal brain surface of 44 rats was irradiated with a focused laser beam at a constant output energy of 30 J. Survival times ranged from 5 minutes to 48 hours. Laser irradiation immediately caused well-defined cortical coagulation necrosis. Within 5 minutes after unilateral irradiation, 14C-iodoantipyrine autoradiographs demonstrated severely reduced blood flow to the irradiation site and perilesional neocortex, but a distinct reactive hyperemia in all other areas of the forebrain. Apart from a persistent ischemic focus in the vicinity of the cortical coagulation necrosis, blood flow alterations in remote areas of the brain subsided within 3 hours after irradiation. Autoradiographic assessment of 3H-tyrosine incorporation into brain proteins revealed rapid onset and prolonged duration of protein synthesis inhibition in perifocal morphologically intact cortical and subcortical structures. Impairment of amino acid incorporation proved to be completely reversible within 48 hours. Immunoautoradiographic visualization of extravasated plasma proteins using 3H-labeled rabbit anti-rat immunoglobulins showed that, up to 1 hour after irradiation, immunoreactive proteins were confined to the neocortex at the irradiation site. At 4 hours, vasogenic edema was present in the vicinity of the irradiation site and the subcortical white matter, and, at later stages (16 to 36 hours), also extended into the contralateral hemisphere. Although this was followed by a gradual decrease in labeling intensity, resolution of edema was still not complete after 48 hours.
Analysis of sequential functional changes in conjunction with morphological alterations indicates that the evolution of morphological damage after laser irradiation does not correlate with the time course and spatial distribution of protein synthesis inhibition or vasogenic edema. Although the central coagulation necrosis represents a direct effect of radiation, the final size of the laser-induced lesion is determined by a delayed colliquation necrosis due to persistent perifocal ischemia. Extent and severity of ischemia in a zone with initial preservation of neuroglial cells can be explained by the optical properties of the Nd:YAG laser; extensive scattering of light within brain parenchyma associated with a high blood-to-brain absorption ratio selectively affects blood vessels outside the irradiation focus.
New technique of side-to-end hypoglossal—facial nerve attachment with translocation of the infratemporal facial nerve
Authors: Darrouzet Vincent , Guerin Jean , Bébéar Jean-Pierre 
Published: May 2009

Object. The goal of this study was to assess the clinical results of hypoglossal-facial nerve attachment (HFA), which was primarily performed in patients following excision of tumors of the cerebellopontine angle. In six of the patients a new side-to-end procedure was used.Methods. The authors have performed a retrospective study of 33 patients who underwent HFA, including 24 classic end-to-end, three May, and six side-to-end procedures. For the latter procedure, a hemihypoglossal—facial nerve attachment was performed by rerouting the intratemporal facial nerve; this avoided the jump-cable graft used in May's technique. The goal of the new procedure is to reduce the incidence of morbidity due to hemilingual paralysis (difficulty in chewing, speaking, and swallowing). The incidence of hemilingual paralysis was evaluated based on the findings of a questionnaire that was completed by the patients. The patient's facial mobility was assessed using the House and Brackmann grading system and the author's analytic scoring system.Conclusions. The HFA offers good functional results. Of the 28 cases evaluated, nine had House and Brackmann Grade III, 17 Grade IV, and only two Grade V at 18 months. When the new technique of side-to-end hemihypoglossal—facial nerve attachment was used, there was considerable reduction, if not complete disappearance, of lingual morbidity and the facial functional results were constant and satisfactory: there were five patients with House and Brackmann Grade III and one with Grade IV, and their mean percentage of facial mobility was 43.3%.