bluuebunny/crossref_metadata_2025 huggingface dataset:
Quasi - 3D and Full - 3D Approaches for Numerical Simulation in Axial Flow Hydraulic Turbine
Authors: Prasad Vishnu , Sayann K. S. , Krishnamachar P
Published: May 2009

Water passes through the rows of stationary and rotating blades in the turbine space and thus the flow becomes complex. The application of computational fluid dynamics (CFD) is steadily increasing to improve design of hydraulic turbines. The numerical flow simulation in the hydraulic turbine space can either be based on potential or viscous flow theory. In both the approaches, detailed flow behavior in complete turbine space is obtained. The quasi- 3D potential flow approach is quick and simple as compared to full-3D viscous flow methods of analysis but do not take into account the friction losses, which need to be computed separately. The direct flow analysis has been carried out in an experimentally tested model of axial flow hydraulic turbine using the two approaches and the comparison of flow pattern and computed parameters in runner is made in present paper. The computed efficiencies and other performance parameters have also been compared with experimental values at some critical points for validation.Hydro Nepal: Journal of Water, Energy and Environment Issue No. 4, January, 2009 Page 42-48
Relocation Failures in Sri Lanka: A Short History of Internal Displacement and Resettlement By Robert Muggah
Authors: Messerschmidt Don
Published: May 2009

Not AvailableHydro Nepal: Journal of Water, Energy and Environment Issue No. 4, January, 2009 Page 49-51
Conformity or confusion? Changing higher education grading scales as a part of the Bologna Process: the cases of Denmark, Norway and Sweden
Authors: Dahl Bettinal Lien , Lindberg-Sand Åsa
Published: May 2009

The aim of the Bologna Process is to make higher education systems across Europe more transparent. It is crucial for this purpose that confusion concerning the characteristics of the systems should be replaced by conformity. But, as we will show, conformity brought about at one level may create confusion at another. The curricular aspect of the Bologna Process focuses on a shift to outcome-based and student-centred programmes. Syllabi should now be based on intended learning outcomes (ILOs) and should be adjusted to general level descriptors for qualifications. However, the Bologna documents give no explicit recommendations about the use of grading scales. In Denmark, Norway and Sweden, the reforms of higher education induced by the Bologna process included a change of grading scales and referred to the European Credit Transfer and Accumulation System (ECTS). Through these three case studies, we describe and analyse the political process and argumentation underpinning the decisions to change the grading scales in each country. This includes the problems, both experienced and perceived, with the old grading scales, the various national assessment traditions and the new grading scales. The purpose of the change was not the same in each country, but the ongoing adaptation to a seven-step grading scale was thought to ease the international recognition of the national grades, making mobility easier. Though a seven-step grading scale was implemented in both Danish and Norwegian higher education and also by an increasing number of Swedish higher education institutions, the translation of grades only works on a superficial level. The grading scales designed are fundamentally different as classification systems; they attach different numerical values to grades with identical labels and they relate differently to norm- and standards-referenced judgements of learning outcomes. The information condensed in similar grades from the three countries cannot be equated. The vision of simple transparency turns out to be an illusion.
Selection bias, survival, and brachytherapy for glioma
Authors: Florell Randall C. , Macdonald David R. , Irish William D. , Bernstein Mark , Leibel Steven A. , Gutin Philip H. , Cairncross J. Gregory
Published: May 2009

✓ Interstitial irradiation is a promising treatment for malignant glioma. Longer than expected survival periods following treatment of recurrent tumor have led to the use of brachytherapy as an adjuvant treatment. The impact of patient selection on survival data was studied among candidates for this therapy. Consecutive, conventionally treated adults with newly diagnosed supratentorial tumors were identified retrospectively at a center where experience with glioma is population-based. Based on imaging and performance status, two surgeons and a radiation oncologist designated each patient as either eligible or ineligible for adjuvant brachytherapy. The survival and prognostic factors in the eligible and ineligible groups were analyzed. Overall, the patients eligible for brachytherapy (32% of the series) lived significantly longer than the ineligible patients (16.57 vs. 9.30 months), were younger, and had larger resections and better function. For glioblastoma, 40% of patients were eligible, and lived much longer than those who were ineligible (13.90 vs. 5.80 months). It is concluded that better outcome following adjuvant brachytherapy for glioma is at least in part the result of patient selection. Randomized trials of comparably selected patients will be necessary to demonstrate conclusively that longer survival is also a result of treatment.
Skull base amyloidoma
Authors: Ünal Faruk , Hepgül Kemal , Bayindir Çiçek , Bilge Turgay , İmer Murat , Turantan İnan
Published: May 2009

✓ A mass lesion of amyloid involving the central nervous system is a rare finding. A 64-year-old woman presented with a large amyloidoma at the skull base causing neural tissue compression. The only accompanying disease was an asymptomatic renal cyst. The mass had caused destruction of the bone elements and pathological calcification as seen on x-ray films, computerized tomography (CT) scans, and magnetic resonance (MR) images, and was enhanced after injection of contrast medium on both CT scans and MR imaging.
Spinal subdural abscess
Authors: Bartels Ronald H. , de Jong T. Rob , Grotenhuis J. André
Published: May 2009

✓ Only 44 cases of spinal subdural abscess have been reported to date. The authors present another case and review the relevant literature. The findings of intraspinal gassification on computerized tomography scans and Escherichia coli as the causative organism have not previously been described in relation to spinal subdural abscess. Most frequently, Staphylococcus aureus is the responsible organism. Hematogenous spread of infection from a distant source often takes place. In a surprising number of incidences, iatrogenic causes are the primary foci of spinal subdural abscess.

Spinal subdural abscess is an unpredictable disease, with an unfavorable outcome if left untreated. If there is suspicion of a spinal subdural abscess, urgent radiological examination followed by immediate surgical drainage and appropriate antibiotic therapy is warranted.
Lipoma involving the skull
Authors: Tomabechi Masayuki , Sako Kazuhiro , Daita Go , Yonemasu Yukichi
Published: May 2009

✓ The case of an intraosseous lipoma involving the left frontal bone is reported. Lipomas of the bone are rare; only three cases of lipomas involving the skull have previously been reported. The differential diagnosis includes a healing bone infarction or fracture, meningioma, hemangioma, and fibrous dysplasia. Diagnosis prior to surgery is difficult.
Intracerebral penetration of infrared light
Authors: McCormick Patrick W. , Stewart Melville , Lewis Gary , Dujovny Manuel , Ausman James I.
Published: May 2009

✓ Near infrared transmission spectroscopy of the human cerebrum may allow noninvasive evaluation of cerebral hemoglobin saturation in humans. The emerging spectroscopy configuration for this application is a side-by-side source-receiver construct. The ability of this spectroscopy paradigm to detect changes in intracerebral attenuation by selective injection of the infrared tracer indocyanine green into the internal and external carotid arteries during endarterectomy is evaluated in five adult patients. In all five, simultaneous two-channel infrared transmission spectroscopy over the ipsilateral hemisphere documented tracer bolus transit with a signal-to-noise ratio greater than 100:1. In addition, the two channels could be configured to achieve depth resolution of the collected spectra.
Percivall Pott: an 18th century neurosurgeon
Authors: Flamm Eugene S.
Published: May 2009

✓ This paper examines neurosurgery in the 18th century and suggests that the origins of the specialty can be recognized at the time when surgeons began to use the neurological status of the patient as a guide for surgical intervention. Percivall Pott (1714–1788) was one of the leading surgeons in London in the 18th century. He is remembered through eponyms of Pott's puffy tumor, Pott's fracture, and Pott's disease. A review of his writings and those of his contemporaries indicates that these surgeons were aware of the importance of changes in level of consciousness after head injury. The recognition and significance of the lucid interval was described and understood as a neurosurgical sign in the 18th century. Because of Pott's pre-eminence in the surgery of his time through his writings and lectures, he should be considered one of the founders of neurosurgery as a separate surgical discipline.
Three-dimensional computerized tomography angiography in the diagnosis of cerebrovascular disease
Authors: Harbaugh Robert E. , Schlusselberg Daniel S. , Jeffery Robert , Hayden Shawn , Cromwell Laurence D. , Pluta Daniel
Published: May 2009

✓ Computer-generated three-dimensional reconstruction of the intracranial vascular system obtained by contrast-enhanced computerized tomography (CT) has been used in the diagnosis of 20 patients with known or suspected intracranial cerebrovascular disease. This technique allows visualization of the intracranial vasculature without exposing patients to the risks associated with intra-arterial angiography. The color prints and videotape images generated have been used to diagnose the presence of intracranial aneurysms, arteriovenous malformations, and venous angiomas. They have also been used to rule out structural abnormalities in patients with suspected intracranial vascular pathology and to screen patients with a strong family history of intracranial aneurysm. In 11 patients who underwent both three-dimensional CT angiography and intra-arterial angiography, the diagnostic correlation was 100%. No complications from the procedures or from incorrect diagnosis have been encountered. Although this technique requires further development and clinical evaluation, the authors' early experience with three-dimensional CT angiography suggests that this may become a valuable tool in the diagnosis of patients with cerebrovascular disease.
The relationship of ventricular drainage to aneurysmal rebleeding
Authors: Paré Laura , Delfino Ralph , Leblanc Richard
Published: May 2009

✓ Given the widespread use of continuous external ventricular drainage in patients with aneurysmal subarachnoid hemorrhage (SAH), this investigation was undertaken to define the relationship of ventricular drainage to aneurysmal rebleeding. A historical cohort study of 128 patients with confirmed aneurysmal SAH was performed using a multivariate stepwise logistic regression analysis to examine the relationship between aneurysmal rerupture and ventricular drainage, while controlling for important clinical and radiological independent variables. The variables for ventricular drainage selected in the regression analysis were clinical grade, aneurysm size, and presence of hydrocephalus. The rate of rerupture was significantly higher in cases with ventricular drainage (odds ratio 5.31:1, p < 0.05), poor clinical grade (odds ratio 4.90:1, p < 0.02), and large aneurysm size (odds ratio 11.25:1, p < 0.01). The significant effect of ventricular drainage was limited to patients with hydrocephalus. The increased risk of aneurysmal rebleeding in patients undergoing ventricular drainage may result from both: 1) a rise in aneurysmal transmural pressure, since intracranial pressure is lowered by ventricular drainage; and 2) an association between ventricular drainage and a more severely disrupted aneurysm which is more prone to rebleed as part of its natural history. This study found an increased risk of aneurysmal rebleeding among patients undergoing ventricular drainage, particularly in the presence of hydrocephalus.
Oligodendrogliomas: the Mayo Clinic experience
Authors: Shaw Edward G. , Scheithauer Bernd W. , O'Fallon Judith R. , Tazelaar Henry D. , Davis Dudley H.
Published: May 2009

✓ Eighty-one patients with pure supratentorial oligodendrogliomas underwent surgery alone (19 patients) or surgery plus postoperative radiation therapy (63 patients) between the years 1960 and 1982. The median survival time and the 5-, 10-, and 15-year survival rates for these 82 patients were 7.1 years, 54%, 34%, and 24%, respectively; these values were significantly different from those for an age- and sex-matched normal reference population. Univariate and multivariate survival analyses were performed on 13 possible prognostic factors including: patient age and sex; presence of seizures; site, size, side, computerized tomography (CT) enhancement, grade, and calcification of the tumor; and treatment (extent of surgical resection, lobectomy, radiation dose, and radiation field). Of these factors, tumor grade as classified by the Kernohan and St. Anne-Mayo methods was most strongly associated with survival. Patients with Grade 1 or 2 tumors by either grading method had a median survival time and 5- and 10-year survival rates of approximately 9.8 years, 75%, and 46%, respectively, compared to 3.9 years, 41%, and 20% for those with Grade 3 or 4 tumors. The extent of surgical resection was also associated with survival. The 19 patients who underwent gross total resection of their tumor had a median survival time and 5- and 10-year survival rates of 12.6 years, 74%, and 59%, compared to 4.9 years, 46%, and 23%, respectively, for the 63 who had subtotal resection. When comparing the 19 patients who underwent surgery alone with the 63 who had surgery plus postoperative radiation therapy, there did not appear to be a survival benefit to be gained from the addition of postoperative radiation therapy. However, the patients who had surgery alone tended to have gross total resections and lower tumor grades. Analysis of the subset of 63 patients who underwent subtotal resection alone or with radiation therapy showed that the median survival time and 5- and 10-year survival rates were: 2 years, 25%, and 25% for the eight patients with subtotal resection alone; 4.5 years, 39%, and 20% for the 26 patients with surgery and low-dose (< 5000 cGy) radiation therapy; and 7.9 years, 62%, and 31% for the 29 patients receiving surgery and high-dose radiation therapy (≥ 5000 cGy), respectively.
Stereotactic radiosurgical treatment of brain metastases
Authors: Adler John R. , Cox Richard S. , Kaplan Irving , Martin David P.
Published: May 2009

✓ In a series of 33 patients with reasonably controlled primary cancers, stereotactic radiosurgery was used to treat 52 brain metastases. After a mean radiological follow-up time of 5.5 months, six lesions (12%) had stabilized in size, 26 (50%) were significantly reduced, and 15 (29%) had disappeared. One large melanoma metastasis progressed relentlessly despite treatment. Five lesions (9%) had decreased in size slightly before enlarging. In two of these lesions, biopsy revealed only necrosis. In almost all cases, treatment was associated with decreased peritumoral edema. However, a group of patients with large metastases and extensive prior brain irradiation has been identified in whom prolonged symptomatic cerebral edema poses a problem. It is concluded that radiosurgery is a viable alternative to surgical resection for some cases of brain metastasis.
Transient glucose hypermetabolism after acute subdural hematoma in the rat
Authors: Kuroda Yasuhiro , Inglis Fiona M. , Miller Jimmy D. , McCulloch James , Graham David I. , Bullock Ross
Published: May 2009

✓ Ischemic brain damage occurs in most patients with acute subdural hematoma, yet many aspects of the distribution and extent of this damage remain unexplained. Previous studies in rat model, which produces a region of infarction under the hematoma, have implicated an “excitotoxic” mechanism, suggesting that high concentrations of excitatory amino acids may exacerbate ischemic damage.

A study is described in which local glucose utilization is measured 2 or 4 hours after induction of acute subdural hematoma in the rat. These changes are compared to those produced by introducing the same volume of inert silicone gel into the subdural space. Massive increases (up to 142%) in glucose utilization occurred throughout both hippocampi and in a variable zone around the ischemic core, but these had normalized by 4 hours after blood injection. Hippocampal hypermetabolism was not seen after introduction of the silicone mass, suggesting that diffusible substances from the clotted blood may be responsible for these changes. This transient hypermetabolism accords with an excitotoxic process, which may amplify brain damage after acute subdural hematoma.
Time course of the impairment of cerebral autoregulation during chronic cerebral vasospasm after subarachnoid hemorrhage in primates
Authors: Handa Yuji , Hayashi Minoru , Takeuchi Hiroaki , Kubota Tetsuya , Kobayashi Hidenori , Kawano Hirokazu
Published: May 2009

✓ The time course of the impairment of cerebral autoregulation during chronic cerebral vasospasm after subarachnoid hemorrhage was studied in 18 monkeys. Changes in cerebral blood flow (CBF) at the regional level and central conduction times during either graded hypo- or hypertension were evaluated in these animals at three stages (3, 7, and 14 days) following the introduction of an autologous blood clot around the right middle cerebral artery (MCA). Angiograms revealed a reduction in vessel caliber (compared to the baseline level in the involved MCA) of 30% at 3 days, 50% at 7 days, and 10% at 14 days. At all stages, CBF remained constant at mean arterial blood pressures (MABP) of 60 to 160 mm Hg in the noninvolved hemisphere. In contrast, at the 3- and 7-day stages, there was an impairment of autoregulation in the involved hemisphere at MABP of 40 to 180 mm Hg. The right hemispheric CBF was significantly (p < 0.05) lower than that in the left throughout the period of investigation at MABP below 120 mm Hg, but rose to exceed the left CBF at MABP above 180 mm Hg at the 7-day stage and 160 mm Hg at the 14-day stage. The right-sided central conduction time showed significant (p < 0.05) prolongation at MABP below 60 mm Hg at the 3-day stage and 40 mm Hg at the 7-day stage. It is suggested that these results may help to develop guidelines for hemodynamic therapy for vasospasm in its various stages.
Development of multidrug resistance in a primitive neuroectodermal tumor cell line
Authors: Tishler David M. , Raffel Corey
Published: May 2009

✓ Drug resistance remains a formidable obstacle to the successful treatment of pediatric primitive neuroectodermal tumors. Resistance to chemotherapeutic agents may be related, in part, to expression of the multidrug resistance gene 1 (MDR1). The protein product of this gene, P-glycoprotein, confers resistance to multiple unrelated antineoplastic drugs.

The cell line DAOY, derived from a primitive neuroectodermal tumor, was used as an in vitro model to examine the development of drug resistance. Cell lines resistant to actinomycin D were developed by the growth of DAOY in increasing concentrations of the drug. The IC50 (concentration of drug needed to induce a 50% reduction in cell growth) of the resultant lines to actinomycin D was more than 10 times that of the parental line. The resistant lines were cross-resistant to VP-16 (etoposide), despite lack of previous exposure to this drug. The resistance to actinomycin D was attenuated in the presence of verapamil, a known inhibitor of P-glycoprotein. The MDR1 gene was not expressed by the parental DAOY line at the messenger ribonucleic acid (RNA) and protein level. Expression of the MDR1 gene was documented in the resistant lines by RNA blot and immunoblot techniques. These results suggest that exposure to chemotherapeutic drugs can induce classical multidrug resistance in primitive neuroectodermal tumors.
Treatment of murine primary brain tumors with systemic interleukin-2 and tumor-infiltrating lymphocytes
Authors: Saris Stephen C. , Spiess Paul , Lieberman Daniel M. , Lin Shan , Walbridge Stuart , Oldfield Edward H.
Published: May 2009

✓ Methods have recently been described for the isolation and expansion of lymphocytes that have trafficked into animal and human tumors. These CD8-positive tumor-infiltrating lymphocytes (TIL's) have exceptional trafficking ability to, and efficacy against, tumor targets in extracranial sites. Prior to Phase I clinical trials for patients with gliomas, adoptive immunotherapy with TIL's was studied in a mouse model of primary brain tumors to determine if intracerebral tumors have a similar response.

Glioma 261 (GL261) tumors were grown in the subcutaneous space of C57BL/6 mice. After enzymatic digestion, the cells were incubated in vitro with interleukin-2 (IL-2) until a confluent population of T lymphocytes was present. The in vitro efficacy of these TIL's was tested against fresh GL261 targets with a chromium release assay; the in vivo efficacy was tested against GL261 tumors in the liver and against irradiated and nonirradiated GL261 tumors in the brain. Mice received one of the following: intraperitoneal saline; intraperitoneal IL-2 (7500 to 50,000 U three times daily for 5 days); IL-2 plus intravenous TIL's (1 to 3 × 107 cells); 10 Gy cranial irradiation; irradiation plus IL-2; or irradiation plus IL-2 plus TIL's.

The TIL preparation killed 77% of tumor targets in 4 hours at an effector:target ratio of 100:1. In animals with GL261 tumors in the liver, at 2 weeks there were 93 ± 37, 128 ± 45, and 21 ± 14 liver metastases in the control, IL-2, and IL-2 plus TIL groups, respectively. However, in animals with GL261 tumors in the brain, no treatment group had an increased survival rate compared to the control group.

It is concluded that, although TIL and IL-2 immunotherapy can be used effectively to treat brain tumors in vitro and at sites outside the central nervous system, it is ineffective against the same type of tumor in the brain. Different methods of delivery or different combinations of these immunomodulators may be more effective; however, based on these findings, treatment of patients with IL-2 and TIL cannot be recommended until efficacy has been demonstrated in an animal model.
Intramedullary epidermoid cysts of the spinal cord
Authors: Roux Alain , Mercier Claude , Larbrisseau Albert , Dube Louis-Jacques , Dupuis Céline , Del Carpio Raquel
Published: May 2009

✓ Epidermoid cysts are tumors familiar to neurosurgeons, but intramedullary epidermoid cysts are rare. The authors report the case of a 6-year-old girl presenting with progressive paraparesis. A midthoracic intramedullary mass was revealed on myelography and magnetic resonance (MR) imaging and confirmed as an intramedullary epidermoid cyst at surgery, at which time the cyst was removed. This is the fourth report documenting a purely intramedullary epidermoid cyst occurring in a child. The pathology and etiology, epidemiology, clinical features, radiology (including MR image characteristics), and surgical treatment of such rare intramedullary benign tumors are discussed. Magnetic resonance imaging reduces the delay in diagnosis of spinal cord tumors but should be guided by clinical judgment.
Ultrasound diagnosis of an intraneural ganglion cyst of the peroneal nerve
Authors: Leijten Frans S. S. , Arts Willem-Frans , Puylaert Julien B. C. M.
Published: May 2009

✓ The authors present the case of an intraneural ganglion cyst of the peroneal nerve. The cyst was diagnosed by means of ultrasound, which also gave an exact definition of its size and location, confirmed at operation. Some controversial aspects of these lesions are discussed.
Histopathological follow-up study of 66 cerebral arteriovenous malformations after therapeutic embolization with polyvinyl alcohol
Authors: Germano Isabelle M. , Davis Richard L. , Wilson Charles B. , Hieshima Grant B.
Published: May 2009

✓ Embolization with polyvinyl alcohol (PVA) is an accepted method of rendering complex arteriovenous malformations (AVM's) more amenable to surgery, but its effects on human vascular tissues have not been adequately documented. The authors reviewed the histopathology of 66 intracranial AVM's resected 1 to 76 days after embolization with PVA. The mean age of the patients was 36 years, and their AVM's were located in the cerebral hemispheres (92%), the cerebellum (6%), or the corpus callosum (2%). In 79% of cases, at least one vessel contained PVA particles; in most cases, the vessel was filled with sharp, angular PVA particles in a serpiginous pattern. Polyvinyl alcohol particles indented the endothelium in 69% of cases but were rarely found subendothelially. Clotted blood and fibroblasts were present among the particles, and abundant intraluminal mononuclear and polymorphonuclear inflammatory cells were found in all vessels containing PVA particles. Foreign-body giant cells appeared 2 to 14 days after embolization in the majority of cases. Patchy mural angionecrosis and necrotizing vasculitis were found in 39% of the cases. Recanalized lumina were seen in 18% of PVA-embolized vessels. Foreign materials resembling cotton fibers and other particulate substances, which were probably contaminants of the contrast solution or the embolic material, were found in 65% of the cases. These findings suggest a specific chain of events in the interaction between PVA and vessel wall components and may explain some important sequelae of embolization therapy.
Severe limitation in mouth opening following transtemporal neurosurgical procedures: diagnosis, treatment, and prevention
Authors: Nitzan D. W. , Azaz B. , Constantini S.
Published: May 2009

✓ Five new patients and six previously described patients with severe limitation in maximum mouth opening following transtemporal neurosurgical procedures are described. Six patients underwent an operation for epidural hematoma and three for skull-base meningioma; two were treated with a pterional craniotomy for an aneurysm. Limited maximum mouth opening in these circumstances is caused by temporal muscle scarring and shortening. Aggressive physiotherapy is potentially beneficial if started early. If, however, diagnosis is delayed, the efficacy of physiotherapy declines, and surgical treatments such as temporal muscle detachment and coronoidectomy are fully indicated. The differential diagnosis, prevention, and treatment of limited maximum mouth opening following neurosurgical procedures are discussed.
Rapid polymerizing fibrin glue from autologous or single-donor blood: preparation and indications
Authors: Stechison Michael T.
Published: May 2009

✓ A recipe for the preparation of a rapid polymerizing fibrin glue from single-donor or autologous blood products is presented. An in vitro investigation of different recipes with study of polymerization times, consistency, and in vitro survival of the product is described. The preparation in the operating room and the indications for clinical use of this glue in neurosurgery are discussed. The results of its use in a series of 38 patients is presented, including those undergoing surgery of the skull base, pituitary gland, cranial nerves, and the spine.
Intraoperative anatomical studies in patients with aneurysms of the anterior communicating artery complex
Authors: Nathal Edgar , Yasui Nobuyuki , Sampei Takeshi , Suzuki Akifumi
Published: May 2009

✓ The intraoperative anatomical findings of the anterior communicating artery (ACoA) complex in 46 patients with anatomical variations were compared to those in an equal number of patients without variations in order to determine the visualization of the elements of the vascular complex. All patients underwent radical surgery for an ACoA aneurysm by one of three different surgical approaches: transsylvian, anterior interhemispheric, or basal interhemispheric. Visualization of the vascular elements was similar in patients with or without anatomical variations. The differences observed were dependent on the surgical approach selected and on the projection of the aneurysm. It was found that, even when the intraoperative anatomical field and the number of vascular elements visualized are different from those obtained in autopsy studies, the vascular microanatomical characteristics can be confirmed with each surgical approach to the extent necessary to ensure safe clipping of aneurysms in patients both with and without anatomical variations.
The effect of hemoglobin on vasodilatory effect of calcium antagonists in the isolated rabbit basilar artery
Authors: Toshima Masahiko , Kassem Neal F. , Sasaki Tomio , Tanaka Yuichiro , Machi Takao
Published: May 2009

✓The effect of hemoglobin on the vasodilatory effect of calcium antagonists was studied in isolated rabbit basilar arteries using an isometric tension measurement method. The ability of nimodipine to relax or inhibit contractions elicited by high K+ depolarization or serotonin (5-hydroxytryptamine, 5-HT) was investigated in control arterial rings and rings pretreated by hemoglobin. Hemoglobin (10−6 and 10−5 M) reduced the relaxation induced by nimodipine (10−10 to 10−8 M) in the rings contracted by 40 mM KCl. This reduction in relaxation was also observed with 3 × 10−10 to 3 × 10−9 M nicardipine, 3 × 10−8 to 3 × 10−7 M verapamil, and 10−7 to 10−6 M diltiazem. On the other hand, the effect of nimodipine was not influenced by endothelial removal or by pretreatment with 10−5 M albumin or 10−6 M prostaglandin F2α Hemoglobin restored the 10−10 and 10−9 M nimodipine-induced inhibition of the contraction elicited by CaCl2 (0.3 to 20 mM) in a K+-rich, Ca++-free solution. This restoration was greater at higher concentrations of CaCl2. Hemoglobin enhanced both the nimodipine-sensitive tonic phase and the less sensitive phasic phase of contractions produced by 10−6 M of 5-HT. It abolished the inhibitory effect of 10−8 and 10−7 M nimodipine on the phasic contraction. Endothelial removal also enhanced both phases of the contraction, but did not abolish the effect of nimodipine. This study showed that the vasodilatory effect of calcium antagonists, especially nimodipine, on the vasoconstriction induced by other vasoactive substances decreased in the presence of hemoglobin.
Laser-induced fluorescence: experimental intraoperative delineation of tumor resection margins
Authors: Poon Wai S. , Schomacker Kevin T. , Deutsch Thomas F. , Martuza Robert L.
Published: May 2009

✓ The ability of laser-induced fluorescence spectroscopy to delineate tumor margins intraoperatively was studied using a rat intracerebral glioma model. A fluorescent dye, chloro-aluminum phthalocyanine tetrasulfonate (ClAlPcS4), was injected intravenously 24 hours before tumor resection. The animals underwent tumor resection under the operating microscope, guided by laser-induced fluorescence measurement in one group (Group 1) and visual assessment in the other (Group 2). The Group 1 rats had a significantly reduced volume of residual tumor following resection (0.5 ± 0.2 cu mm vs. 13.7 ± 4.0 cu mm, mean ± standard error of the mean, p < 0.02). Three of the nine animals in Group 1 were tumor-free at 2 weeks following resection, compared with none of the 10 rats in Group 2 (p < 0.05). Interference from brain autofluorescence was minimized using spectrally resolved detection and the ClAlPcS4 dye, which has a 680-nm fluorescence peak significantly higher than the 470-nm autofluorescence peak of normal brain. Contrast ratios of up to 40:1 were found for glioma:normal brain fluorescence signals. Spatially-resolved spectra were acquired in approximately 5 seconds using a fiberoptic probe. This study demonstrates the ability of an intraoperative laser-induced fluorescence system to detect tumor margins that could not be identified with the operating microscope.
Preserved spinal dorsal horn potentials in a brain-dead patient with Lazarus' sign
Authors: Urasaki Ehchirou , Tokimura Toshiyuki , Kumai Jun-ichirou , Wada Shin-ichi , Yokota Akira
Published: May 2009

✓ The case of a brain-dead patient with complex movements of the extremities (Lazarus' sign) is reported. This is the first description in the literature of short-latency somatosensory evoked potentials (SSEP's) following median-nerve stimulation by a noncephalic reference method. The scalp P14 wave (a far-field positivity with a peak latency around 14 msec that originates from the cervicomedullary junction) disappeared, and the spinal N13 wave (a near-field negativity with a 13-msec peak recorded on the posterior neck and generated by the cervical dorsal horn) was preserved. Respiratory-like movement was also seen in this case. The SSEP findings support the hypothesis that both Lazarus' sign and respiratory-like movement have a spinal origin.
The treatment of oligodendrogliomas and mixed oligodendroglioma-astrocytomas with PCV chemotherapy
Authors: Glass Jon , Hochberg Fred H. , Gruber Michael L. , Louis David N. , Smith David , Rattner Barbara
Published: May 2009

✓ Malignant oligodendrogliomas have been shown to be responsive to chemotherapy. The authors administered systemic chemotherapy to seven patients with oligodendroglioma or anaplastic oligodendroglioma, and to 14 with mixed oligodendroglioma-astrocytoma. Fourteen patients underwent chemotherapy before and seven after irradiation. The PCV (procarbazine, methyl-1-(2-chloroethyl)-1-nitrosourea (CCNU), and vincristine) chemotherapy was administered every 6 weeks (42-day cycles) for two to five cycles as follows: CCNU, 110 mg/sq m on Day 1; procarbazine, 60 mg/sq m/day on Days 8 to 21; and vincristine, 1.4 mg/sq m/day on Days 8 and 29. Complete or partial (> 50% reduction in tumor mass) responses at 20 to 100+ weeks after treatment were noted in 11 (79%) of the 14 patients treated before irradiation, including two with anaplastic oligodendroglioma and nine with mixed tumors. Complete responses were seen in two patients, one with anaplastic oligodendroglioma and one with a mixed tumor. Partial responses were seen in three of seven patients treated after radiotherapy. Stabilization of tumor growth followed PCV chemotherapy in four patients (two treated before and two after radiotherapy). Tumor growth progressed in two patients during therapy despite an initial response and in two patients despite therapy. The authors conclude that mixed oligodendroglial tumors as well as anaplastic oligodendrogliomas are responsive to PCV chemotherapy.
Thromboendarterectomy of the symptomatic occluded internal carotid artery
Authors: McCormick Patrick W. , Spetzler Robert F. , Bailes Julian E. , Zabramski Joseph M. , Frey James L.
Published: May 2009

✓ A retrospective review of 42 patients (mean age 61.4 years) with surgically managed symptomatic internal carotid artery occlusion is reported. A standardized surgical protocol aimed at restoration of flow in the vessel was used. Presenting symptoms included hemispheric transient ischemic attacks in 68% of patients, new fixed neurological deficits in 28%, amaurosis fugax in 28%, and stroke-in-evolution in 9%. Twenty-four arteries were successfully reopened. A proximal remnant angioplasty (stumpectomy) was performed alone in nine patients or in combination with an external carotid endarterectomy in nine. In four patients with persisting symptoms who failed to achieve primary restoration of flow, a superficial temporal-to-middle cerebral artery bypass procedure was performed.

The permanent surgical morbidity rate was 2% and the surgical mortality rate was 0%. Transient postoperative deficits were present in three patients (7%). Follow-up review at a mean of 40 months was obtained in 39 patients (93%). Following surgical intervention, five patients died of unrelated causes, two had neurological events consistent with a transient cerebral ischemic attack, and two had vertebrobasilar insufficiency. No patient suffered from stroke.

Of the 24 successfully reopened vessels, follow-up ultrasound evaluations were obtained in 17 (73%) at a mean of 28 months after surgery. In 15 patients (88%) the vessels were widely patent, one (5.8%) had stenosis greater than 70%, and one (5.8%) showed asymptomatic reocclusion.

Reopening occluded internal carotid arteries in selected patients is associated with low surgical morbidity and mortality rates. Further studies are necessary to determine the impact of this surgical therapy on the natural history of this condition.
Intraventricular neurocytoma: clinicopathological analysis of seven cases
Authors: Kim Dong Gyu , Chi Je G. , Park Sung Hye , Chang Kee Hyun , Lee Sun Ho , Jung Hee-Won , Kim Hyun Jib , Cho Byung-Kyu , Choi Kil Soo , Han Dae Hee
Published: May 2009

✓ A retrospective analysis of seven patients with intraventricular neurocytoma is presented. Patient age at diagnosis ranged from 15 to 38 years (mean 24.6 years) and the male:female ratio was 6:1. Raised intracranial pressure due to hydrocephalus was the main cause of the clinical manifestations. An isodense mass with multiple intratumoral cysts and homogeneous contrast enhancement was the characteristic computerized tomography finding. The lesions commonly involved the lateral ventricle with or without extension to the third ventricle. Cerebral angiography showed homogeneous vascular staining in five patients. Magnetic resonance images revealed a mass isointense with the cerebral cortex on both T1 and T2-weighted images. Gadolinium-diethylenetriaminepenta-acetic acid-enhanced images showed homogeneous enhancement. Total removal of the tumor was possible in four patients. Pathologically, six cases were initially diagnosed as oligodendroglioma and the remaining case as ependymoma. However, immunohistochemical studies demonstrated strong positivity for neuron-specific enolase in all seven cases and for synaptophysin in five cases. On electron microscopy, three cases showed well-defined neurosecretory granules and 10-nm microtubules in their cytoplasm and cytoplasmic processes. One patient developed a recurrent tumor 18 months after surgery. The remaining six patients are free of recurrent tumors at 2 to 62 months after surgery. It is suggested that neurocytoma must be included in the differential diagnosis of intraventricular lesions, and that electron microscopic and immunohistochemical studies should be undertaken.
Adhesion molecules and malignant gliomas: implications for tumorigenesis
Authors: Couldwell William T. , de Tribolet Nicolas , Antel Jack P. , Gauthier Thierry , Kuppner Maria C.
Published: May 2009

✓ Adhesion molecules, a family of cell-surface molecules, are likely to be of central importance in mediating cell-extracellular matrix and specific cell-cell interactions within both neoplastic and inflammatory sites. The recently discovered expression of adhesion molecules on glioma cells, tumor-infiltrating lymphocytes, and endothelial cells within the tumor offers insight into the molecular basis of the interactions both between the glioma cell and surrounding heterologous cell types within the tumor environment, and between the tumor cell and the extracellular matrix. Such interactions suggest that these molecules may play roles in the homing of immune cells to these tumors and in regulating the extent of local tumor invasion. The ability to modulate adhesion molecule expression on either immune cells or their respective ligands on gliomas provides an approach to modify cell-cell interactions that may be used to increase tumor kill by the immune system. A similar approach in the modulation of adhesion molecules involved in tumor cell adhesion to the extracellular matrix or endothelial cells may be a method to limit local invasion in these lesions.
Endothelial cell chemotactic factor derived from human glioma cell lines
Authors: Takaki Shuichi , Kuratsu Jin-Ichi , Mihara Yosuke , Yamada Masaharu , Ushio Yukitaka
Published: May 2009

✓ The authors report a study of the human umbilical vein endothelial cell chemotactic factor derived from human malignant glioma cell lines. The endothelial cell chemotactic activity of serum-free conditioned medium from cultures of U-373MG, U-251MG, or U-105MG cell lines was measured using a 48-well microchemotaxis chamber. The best response was from U-373MG, which was selected for further study. Chemotactic activity was contained in materials unadsorbed and adsorbed to the heparin-affinity column. Because the higher activity was seen in the unadsorbed material, it was used for characterization and partial isolation. The chemotactic activity was decreased under the condition of tumor protein synthesis inhibition. Heating, exposure to acid, and trypsin digestion also decreased the activity. The factor was found to be a protein with a relative molecular weight of greater than 200 kD; it has no mitogenic activity for endothelial cells in vitro and, partially purified, it was not identical to any other known endothelial cell chemotactic or mitogenic factor. Fibronectin was not detected, and anti-fibronectin antibody failed to inhibit the activity of the factor. These results suggest that malignant glioma cells produce a yet unknown endothelial cell chemotactic factor.
In vitro efficacy of transferrin-toxin conjugates against glioblastoma multiforme
Authors: Hall Walter A. , Godal Aslak , Juell Siri , Fodstad Øystein
Published: May 2009

✓ The cytotoxic activity of immunotoxins constructed with human diferric transferrin (Tfn) as the carrier ligand and an abrin variant Pseudomonas exotoxin A (PE) and the diphtheria toxin mutant cross-reacting material (CRM) 107 as the toxin moieties were studied in vitro. Three malignant human cell lines, the glioblastomas multiforme SNB19 and SF295 and the LOX melanoma, and a nonhuman control murine melanoma cell line B16 were assessed. The presence of transferrin receptors on the cell lines was confirmed by direct 125I-Tfn binding assays. The 50% protein synthesis inhibitory concentration (IC50) values for all cell lines demonstrated that Tfn-abrin variant and Tfn-PE had comparable potency and were both more effective than Tfn-CRM 107. Monensin, a carboxylic ionophore, potentiated the effect of Tfn-abrin variant against glioma cells approximately 35-fold with IC50 values of 4.0 × 10−13 M and 4.7 × 10−12 M for SNB19 and SF295, respectively. Cytotoxic activity of Tfn-abrin variant (with or without monensin) and Tfn-PE was correlated with the degree of Tfn receptor expression measured on the cell lines. The exquisite in vitro cytotoxicity of Tfn-abrin variant and Tfn-PE immunotoxins against glioma and melanoma cells warrants further in vivo evaluation and future consideration of these agents for potential clinical application against glioblastoma multiforme and leptomeningeal neoplasia.
Reconstitution of shunted mantle in experimental hydrocephalus
Authors: Yamada Haruyuki , Yokota Akira , Furuta Akiko , Horie Akio
Published: May 2009

✓ The morphological mechanism of the reconstitution of shunted mantle was studied histopathologically in 22 kaolin-treated hydrocephalic puppies. A remarkable attenuation of cerebral mantle to less than 1 cm in thickness was seen on computerized tomography (CT) scans of four animals sacrificed 1 to 2 months after kaolin treatment (preshunt group). Ventricular shunting resulted in successful recovery of the mantle on repeated CT scans obtained 1 to 2 months after shunting in seven animals (postshunt group). In the remaining 11 animals the cerebral mantle, which had been reduced to 4 mm in thickness prior to shunting, failed to recover even 2 months after the procedure (shunt-refractory group).

On gross inspection, the preshunt specimens showed marked thinning of the white matter, with the cortical ribbon well preserved, while the postshunt specimens consisted predominantly of thickened white matter. Histopathological examination of the attenuated white matter of the preshunt specimens showed decreased nerve-fiber density, myelin destruction with myelin regeneration and/or repair of myelin sheaths, and reactive astrocytosis, which were prominent especially in the periventricular white matter. The main findings in the reconstituted white matter of the postshunt specimens were extensive myelin regeneration of residual axons and remarkable astroglial proliferation with mesenchymal reaction, particularly at capillaries. No clear evidence of increased numbers of nerve fibers or axonal regeneration was observed. The shunt-refractory specimens showed remarkable attenuation of cortex, in which reduced numbers of neurons and loss of cortical lamination were noted, with vestigial white matter.

The results indicate that astroglial proliferation with mesenchymal reaction and myelin regeneration contribute to the reconstitution of the cerebral mantle volume following ventricular shunting in this model. It is suggested that the critical factor for mantle reconstitution in chronic hydrocephalus is whether cortex is preserved.
Intraoperative localization of the central sulcus by cortical somatosensory evoked potentials in brain tumor
Authors: Suzuki Akifumi , Yasui Nobuyuki
Published: May 2009

✓ Perplexing findings of cortical somatosensory evoked potentials (SEP's) for determining the central sulcus during a craniotomy are reported in a case of brain tumor. On stimulation of the contralateral median nerve in that patient, phase-reversal of SEP waves N1 and P2 was observed not only across the central sulcus but also across the precentral sulcus. In topographic mapping of the N1-P2 amplitude, the sulcus dividing the maximum polarity was the central sulcus; this was confirmed by the cortical stimulation-evoked motor responses. For accurate localization of the central sulcus by cortical SEP's, the distribution of potentials must be analyzed with extensive exposure of the sensorimotor cortex.
A newly designed puncture needle for suction decompression of giant aneurysms
Authors: Kyoshima Kazuhiko , Kobayashi Shigeaki , Wakui Kenji , Ichinose Yoshiki , Okudera Hiroshi
Published: May 2009

✓ A newly designed puncture needle for aspirating large or giant aneurysms is described. This puncture needle represents a modification of an intravenous catheter with an internal needle. It is designed to prevent blood from leaking when the internal needle is removed and has a lateral tube for aspiration. Following aneurysm puncture with the parent artery temporarily trapped, the catheter is positioned on the head frame with a brain spatula and a self-retaining retractor. Blood is suctioned through the lateral tube with a syringe or the suction system normally used in the operating room.
Mr. Jefferson's Rotunda
Authors: Bice Raymond C.
Published: May 2009

✓ After retiring from the presidency of the United States, Thomas Jefferson concentrated his latter years on establishing The University of Virginia. He personally undertook the design of the buildings and directed the early days of the institution. The Rotunda, with its famous Dome Room and outside porticos, continues to receive critical acclaim for its architectural design.