bluuebunny/crossref_metadata_2025 huggingface dataset:
Cerebral radioprotection by pentobarbital: dose-response characteristics and association with GABA agonist activity
Authors: Olson Jeffrey J. , Friedman Robert , Orr Kathryn , Delaney Thomas , Oldfield Edward H.
Published: May 2009

✓ Pentobarbital reduces cerebral radiation toxicity; however, the mechanism of this phenomenon remains unknown. As an anesthetic and depressant of cerebral metabolism, pentobarbital induces its effects on the central nervous system by stimulating the binding of gamma-aminobutyric acid (GABA) to its receptor and by inhibiting postsynaptic excitatory amino acid activity. The purpose of this study is to investigate the role of these actions as well as other aspects of the radioprotective activity of pentobarbital.

Fischer 344 rats were separated into multiple groups and underwent two dose-response evaluations. In one set of experiments to examine the relationship of radioprotection to pentobarbital dose, a range of pentobarbital doses (0 to 75 mg/kg) were given intraperitoneally prior to a constant-level radiation dose (70 Gy). In a second series of experiments to determine the dose-response relationship of radiation protection to radiation dose, a range of radiation doses (10 to 90 Gy) were given with a single pentobarbital dose (60 mg/kg intraperitoneally). Further groups of animals were used to evaluate the importance of the timing of pentobarbital administration, the function of the (+) and (−) isomers of pentobarbital, and the role of an alternative GABA agonist (diazepam). In addition, the potential protective effects of alternative methods of anesthesia (ketamine) and induction of cerebral hypometabolism (hypothermia) were examined.

Enhancement of survival time from acute radiation injury due to high-dose single-fraction whole-brain irradiation was maximal with 60 mg/kg of pentobarbital, and occurred over the range of all doses examined between 30 to 90 Gy. Protection was seen only in animals that received the pentobarbital before irradiation. Administration of other compounds that enhance GABA binding (Saffan and diazepam) also significantly enhanced survival time. Ketamine and hypothermia were without protective effect.

Protection from acute radiation-induced mortality by pentobarbital in the rat model is a reproducible phenomenon and is associated with the GABA agonistic activity of the compound. This property of GABA agonists offers the potential for a novel approach to enhancement of the efficacy of radiation therapy in the treatment of brain tumors.
Benzodiazepine receptors and cerebrospinal fluid formation
Authors: Williams Gregg L. , Pollay Michael , Seale Thomas , Hisey Brent , Roberts P. Alex
Published: May 2009

✓ There is autoradiographic evidence that peripheral-type benzodiazepine ligands bind with high affinity to the membranes of choroid plexus tissue. In this study, the binding of a 4′-chloro analog of diazepam (Ro 5-4864) to rabbit choroid plexus and cerebral cortex was accomplished utilizing an in vitro radioactive assay method. A kinetic analysis of this binding revealed a relatively high affinity of this ligand (KD) for peripheral binding sites in plexus tissue (KD = 16.1 nM/mg protein). There was a 4.6-fold greater density of binding sites (total receptor density (Bmax) = 2.3 pmol/mg) in choroidal membrane as compared to cortical tissue (Bmax = 0.5 pmol/mg). In 40 rabbits in which a ventricular perfusion system was used, the rate of cerebrospinal fluid (CSF) formation was observed to decrease some 48% in the presence of 10−4 M Ro 5-4864, although some inhibition of secretory activity was still noted at a CSF concentration of 10−8 M. The choroid plexus tissue levels of adenosine 3′,5′cyclic monophosphate (cAMP) and adenosine triphosphatase (ATPase) were not affected by 10−4 M Ro 5-4864. The results of this study support the notion that the specific benzodiazepine peripheral binding sites in choroid plexus serve to modulate CSF formation. The mechanism of action is poorly understood but does not involve the transport ATPase system or the second messenger cAMP.
Radiosensitization of C6 glioma by thymidine and 41.8°C hyperthermia
Authors: Cohen Justin D. , Robins H. Ian , Javid Manucher J.
Published: May 2009

✓ The cytotoxic, antiproliferative, and radiosensitizing effects of thymidine (a nucleoside metabolite) were studied using the C6 glioma cell line in vitro. Radiosensitization by a combination of thymidine and 41.8°C hyperthermia was also evaluated. Thymidine concentrations above 100 µg/ml completely inhibited C6 proliferation while concentrations of 100 to 1000 µg/ml (for up to 24 hours) decreased C6 cell survival to as little as 7.4% compared to untreated control cells. Radiosensitivity was enhanced by the administration of thymidine alone (400 µg/ml × 24 hours before irradiation); sensitization by 41.8°C hyperthermia alone (1 hour ending immediately before irradiation) was less pronounced. Thymidine and hyperthermia together produced greater radiosensitization than did heat alone or thymidine alone. These data support the further investigation of thymidine as a neuro-oncology radiosensitizer.
Vascular relaxation properties of calcitonin gene-related peptide and vasoactive intestinal polypeptide in subarachnoid hemorrhage
Authors: Nozaki Kazuhiko , Okamoto Shinichiro , Uemura Yoshihiko , Kikuchi Haruhiko , Mizuno Noboru
Published: May 2009

✓ The vascular relaxation effects of calcitonin gene-related peptide (CGRP) and vasoactive intestinal polypeptide (VIP) on the dog basilar artery after experimentally produced subarachnoid hemorrhage (SAH) were examined in vitro by an isometric tension recording method. Both CGRP and VIP induced dose-dependent relaxations in ring segments of the intact basilar artery of control dogs. The vasorelaxant action of CGRP was more potent than that of VIP. The single-injection model of SAH was produced by injection of fresh autologous arterial blood ( 1 ml/kg body weight) into the cisterna magna on Day 0 of the post-SAH period, and the double-injection model was produced by two injections of blood (0.5 ml/kg each) on Days 0 and 2. Narrowing of the basilar arteries on vertebral angiograms was most prominent on Day 3 or 7 in the single- or double-injection model, respectively. Relaxation of the basilar artery induced by CGRP and VIP was to some extent decreased on Days 3 and 7 of the post-SAH period in the single-injection model, and on Days 7 and 14 in the double-injection model. However, the vasorelaxant effects of CGRP and VIP were significantly enhanced on Day 14 of the post-SAH period in the single-injection model, and on Days 28 and 42 in the double-injection model. Subsequently, these effects returned to control levels by Days 28 or 63 in the single- or double-injection model, respectively.
The abnormal pupil in Cheyne-Stokes respiration
Authors: Gonyea Edward F.
Published: May 2009

✓ Cheyne-Stokes respiration commonly induces a rhythmic pupillary dilatation during hyperpnea and constriction during apnea. Failure of a pupil to dilate during hyperventilation indicates underlying sympathetic nerve paralysis. This report deals with an instance in which one pupil failed to constrict during apnea due to oculomotor nerve compression. The periodic respirations and anisocoria disappeared following surgical evacuation of a large ipsilateral subdural hematoma.
Albendazole therapy for subarachnoid and ventricular cysticercosis
Authors: del Brutto Oscar H. , Sotelo Julio
Published: May 2009

✓ Medical or surgical therapy for subarachnoid or ventricular cysticercosis is a controversial issue. The authors report a patient with cysticercus larvae in both ventricular and subarachnoid locations, who was successfully treated with albendazole. Thus, medical therapy has a role in the treatment of these forms of neurocysticercosis.
Cranial nerve palsy as a delayed complication of attempted infanticide by insertion of a stylet through the fontanel
Authors: Notermans Nicolette C. , Gooskens Rob H. J. M. , Tulleken Cees A. F. , Ramos Lino M. P.
Published: May 2009

✓ A child suffered a sixth and seventh cranial nerve palsy due to intracerebral insertion of a stylet. The stylet was introduced through the anterior fontanel, most probably in an attempt at infanticide. The migration of the stylet through the brain was monitored because the child was first examined 6 years earlier. At operation, the cranial part of the stylet lay in the fourth ventricle, compressing the facial nerve as well as the nucleus of the abducens nerve. The lower part of the stylet had reached the C-5 level.
Successful laboratory growth and analysis of CUSA-obtained medulloblastoma samples
Authors: Oakes W. Jerry , Friedman Henry S. , Bigner Sandra H. , Bullock Nancy H. , Bigner Darell D.
Published: May 2009

✓ The development of the Cavitron ultrasonic surgical aspirator (CUSA) has facilitated neurosurgical intervention for removal of central or peripheral nervous system tumors adjacent to or within vital structures. However, laboratory studies defining the phenotypic and genotypic properties of these tumors, both in cell culture and as xenografts in immunoincompetent animals, require viable tumor fragments free of microbial or red blood cell contamination. This report describes the use of a readily available sterile trap with the CUSA which, in conjunction with centrifugation and ammonium chloride lysis of the bloody aspirate, allowed collection of concentrated viable human medulloblastoma tumor cells. These cells were successfully established in cell culture and as transplantable xenografts in athymic mice.
A new technique for closure of the dura following transsphenoidal and transclival operations
Authors: Guity Afrassiab , Young Paul H.
Published: May 2009

✓ Watertight closure of the dura following transsphenoidal operations for pituitary adenoma or hypophysectomy and following transclival operations for paraclival tumors has been technically very difficult. This is true both immediately after the initial approach and later for the treatment of delayed cerebrospinal fluid leakage. An innovative practical technique and special suture-tying instruments and needle designed by the principal author for this purpose have greatly facilitated this procedure. This technique has been applied to both direct dural closure and dural patching with watertight dural closure. The technique is also widely applicable for closing (or suturing) the dura following any procedure through a small opening, such as the dural tears occasionally encountered during lumbar or cervical discectomy, or tacking the tentorium during a craniotomy. The technique and suture-tying instruments are described in detail.
Percutaneous retrogasserian glycerol rhizotomy
Authors: North Richard B. , Kidd David H. , Piantadosi Steven , Carson Benjamin S.
Published: May 2009

✓ Eighty-five medically intractable trigeminal neuralgia patients treated by percutaneous retrogasserian glycerol rhizotomy (PRGR) were followed for 6 to 54 months. The median time to recurrence of symptoms refractory to medical therapy and requiring further intervention was 3 years (by Kaplan-Meier survival analysis). The median time to recurrence of symptoms requiring some form of medical treatment was 2 years. Following repeat PRGR for recurrent symptoms, the median time to recurrence was 1 year. Univariate log rank statistics and multivariate Cox proportional hazards modeling revealed significant associations between favorable outcome and female sex, absence of atypical features or associated cluster headache symptoms, success of prior carbamazepine therapy, duration of symptoms, and cerebrospinal fluid return during the procedure. A scoring system using prognostic factors has been developed based upon these findings.

Assessment of published studies of PRGR and of other treatments for trigeminal neuralgia is made difficult by the variety of outcome measures employed and variable follow-up intervals. The present study attempts to address these issues by definition of endpoints, statistical analysis of the data, and identification of important prognostic factors in a manner useful to the clinician.
Computerized tomography brain scan tumor volume determinations
Authors: Mahaley M. Stephen , Gillespie G. Yancey , Hammett Rita
Published: May 2009

✓ In an effort to define more precisely and objectively computerized tomography (CT) brain scan evidence of glioma patient response to treatment, planimetric measurements of serial CT images of enhancing tumor areas were made using a digitizing tablet interfaced to a microcomputer for computing three-dimensional tumor volumes. The ability of a single investigator to measure a “significant change” in tumor volume was determined from that investigator's coefficient of variation (COV) for triplicate volume measurements (a total of 1701) on 155 scans of 27 patients with malignant gliomas. Planimetric volume data were compared with geometric computation of volumes based upon the product of the maximum diameter of enhancing tumor and the perpendicular diameter for each image made simultaneously with each planimetric measurement. The planimetric method COV was less than that for geometric computation, and the former method was employed for analysis of response to therapy in these same patients. Overall, for a tumor volume change to be significant (COV plus 2 standard errors of the means), the percentage change was determined to be 20%. However, the smaller the tumor volume being measured, the greater was the percentage change required in order to be significant. Thus, minimal measurable changes (%) were separately defined for large (> 14 cc), medium (8 to 14 cc), and small (< 8 cc) tumor volumes. Tumor volumes computed from baseline (prior to investigational therapy) and from subsequent serial CT scans were compared, with response defined as a significant change. Responses to therapy based on significant volume changes were compared in each instance to the conventional visual viewbox comparison (“Gestalt”) of serial scans. In 28% of scan comparisons, planimetric technique sensitivity permitted determination of significant enlargement or reduction in tumor size, while Gestalt comparison suggested no change. The use of quantitative tumor volume analysis of planimetric determinations of changes in tumor size during investigational therapy appears to permit recognition of either progression or regression of tumor size earlier than by Gestalt comparison in one-fourth of instances.
Prolactin gene expression in human growth hormone-secreting pituitary adenomas
Authors: Nagaya Takashi , Seo Hisao , Kuwayama Akio , Sakurai Tsuyoshi , Tsukamoto Nobuhiro , Sugita Kenichiro , Matsui Nobuo
Published: May 2009

✓ To elucidate the mechanism of hyperprolactinemia often observed in patients with growth hormone (GH)-secreting pituitary adenomas, the presence of immunoreactive prolactin (ir-PRL) and prolactin (PRL) messenger ribonucleic acid (mRNA) in the tumor tissue was examined by immunohistochemistry and cytoplasmic dot hybridization. Hyperprolactinemia was observed in three of 18 patients with GH-secreting adenoma. The tumor tissue was demonstrated to contain ir-PRL in nine patients and PRL mRNA in 13. The presence of ir-PRL in the tumor tissue was always associated with positive PRL mRNA, indicating production of PRL in GH-secreting tumors. Among the three patients with hyperprolactinemia, both ir-PRL and PRL mRNA was revealed in the tumor tissue of one, PRL mRNA but not ir-PRL was detected in the adenoma tissue of another, and neither PRL mRNA nor ir-PRL was found in the tumor tissue of the third. The association of hyperprolactinemia with the presence of both ir-PRL and PRL mRNA or PRL mRNA alone is indicative of PRL production and secretion. However, the absence of ir-PRL and PRL mRNA in the tumor tissue may indicate that hyperprolactinemia is caused by the suppression of PRL inhibitory factor due to hypothalamic dysfunction by the tumor mass. Thus, the study of PRL gene expression and immunohistochemistry in GH-secreting adenomas is valuable to understanding the pathophysiology of pituitary tumors.
Transcranial Doppler pulsatility in vasodilation and stenosis
Authors: Giller Cole A. , Hodges Kurt , Batjer H. Hunt
Published: May 2009

✓ Although blood velocity in the major intracranial vessels is readily measured with transcranial Doppler ultrasound (TCD), the interpretation of velocity changes is by no means straightforward. For example, a velocity increase can arise from either a local stenosis or a decrease in downstream resistance, and these mechanisms have contradictory implications for blood flow. To determine whether TCD pulsatility might distinguish these two mechanisms, Doppler ultrasonic readings were taken from an artificial vascular model under conditions of either stenosis or distal dilation. In addition, TCD studies of nine patients with unihemispheric arteriovenous malformations (AVM's) and 16 TCD studies of seven patients with unihemispheric aneurysmal vasospasm were reviewed, and pulsatilities of the AVM's (representing decreased resistance) were compared with those of the vasospastic vessels (representing stenosis).

The average percentage drop in pulsatility in the vasodilated configuration of the model/percentage increase in velocity was 0.38 ± 0.08 (± standard error of the mean), while that for stenosis was 0.20 ± 0.01. Similar comparisons of the patient population yielded 0.67 ± 0.16 for the AVM group and 0.26 ± 0.04 for the vasospasm group. These differences were significant (p < 0.05). The fall in pulsatility associated with a given increase in velocity is significantly greater when the velocity increase arises from diminished downstream resistance than from stenosis.
Selective enhancement of intratumoral blood flow in malignant gliomas using intra-arterial adenosine triphosphate
Authors: Baba Takehiko , Fukui Masashi , Takeshita Iwao , Ichiya Yuichi , Kuwabara Yasuo , Hasuo Kanehiro
Published: May 2009

✓ The effect of intravenous and intracarotid administration of adenosine triphosphate (ATP) on the regional blood flow of glioma patients has been examined by means of positron emission tomography. Intracarotid administration of ATP at a dose of 0.52 to 1.3 µg/kg/min selectively increased the blood flow in the tumor by 26.2% ± 10.5% (mean ± standard deviation). The side effects observed were tolerable. In contrast, intravenous administration of ATP failed to increase tumor blood flow. It is suggested that intracarotid administration of ATP may serve to selectively enhance the delivery of anticancer agents to malignant brain tumors.
Fluid flow performance of a new siphon-control device for ventricular shunts
Authors: Horton Donald , Pollay Michael
Published: May 2009

✓ Most available cerebrospinal fluid diversion systems utilize differential-pressure valves that often induce overshunting, resulting in complications due to the siphoning of fluid from the ventricular system when the patient is in the erect position. A new siphon-control device (SCD) was tested alone and in combination with four types of differential-pressure valves with low, medium, and high opening pressures (namely PS Medical, Heyer-Schulte, Cordis-Hakim, and Codman valves). The valve inlet and outlet pressures were measured at several fluid inflow rates between 2.0 and 50.0 ml/hr. Inlet pressure and valve resistance were determined when the outlet pressures of the differential-pressure valve or SCD were varied between 0 and −60 cm H2O. Of the differential-pressures valves tested, none provided protection against siphoning without the distal connection of the SCD. The SCD allowed all differential-pressure valves tested to maintain atmospheric pressure regardless of the outlet pressure. The SCD performs in a manner similar to the older anti-siphon device, but with some improvements in design and construction. The results of this investigation suggest that the increased resistance due to the inline SCD is not functionally significant when added to the conventional valve systems with low opening pressure.
Autonomic and histopathological effects of percutaneous trigeminal ganglion compression in the rabbit
Authors: Preul Mark C. , Long Phillip B. , Brown Jeffrey A. , Velasco Manuel E. , Weaver Michael T.
Published: May 2009

✓ The histopathological and autonomic effects of percutaneous trigeminal ganglion compression for trigeminal neuralgia were studied in New Zealand White rabbits. Drops in mean arterial blood pressure of 38% and in heart rate of 30% were observed during compression (p < 0.0001). Corneal reflex, pinprick sensation, and mastication strength were intact in 13 of 14 rabbits after compression. These findings resembled the effects of percutaneous compression in humans and suggested that the New Zealand White rabbit is a useful model for the study of percutaneous compression.

Trigeminal sensory roots and ganglia from 14 rabbits killed at intervals from 1 to 84 days after percutaneous compression were sectioned and stained using immunoperoxidase for neurofilaments, hematoxylin and eosin, luxol fast blue, and cresyl echt violet. Focal axonal damage and demyelination were present 7 days after compression. No difference could be detected in the perikaryonal distribution of neurofilaments between compressed and control trigeminal ganglia. Focal demyelination and Schwann cell proliferation preceding remyelination were present in the trigeminal sensory root at 84 days. Differential injury of axons compared to trigeminal ganglion cell bodies suggests that axonal regeneration is possible and may contribute to the recovery of motor and sensory function in patients after percutaneous compression.
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.
Correlation of clinical and pathological features in surgically treated craniopharyngiomas
Authors: Adamson Tim E. , Wiestler Otmar D. , Kleihues Paul , Yaşargil M. Gazi
Published: May 2009

✓ Surgical specimens of 104 craniopharyngiomas from 93 patients were reviewed and characterized histopathologically. They were found to have either a classic adamantinous or a squamous papillary structure. The clinical features of each group were then assessed. The frequently solid (50%), always uncalcified squamous papillary tumor type was found in one-third of the adult patients (≥ 20 years) but did not occur in children. It was associated with a good functional postoperative outcome (84.6%). There have been no cases of tumor recurrence in the squamous papillary group. However, in the group with the adamantinous type of craniopharyngioma, the recurrence rate was 13% in adult patients and 9% in children. When compared to the adult adamantinous cases, the incidence of visual deficits was lower in the squamous papillary group (75% vs. 84%) but the incidence of endocrine abnormalities was higher (75% vs. 52%). Thus, the preoperative, operative, and postoperative features of the two types of craniopharyngioma were found to be distinctly different in adults and children.
Syringomyelia-Chiari complex: magnetic resonance imaging and clinical evaluation of surgical treatment
Authors: Vaquero Jesús , Martínez Roberto , Arias Alicia
Published: May 2009

✓ Thirty patients with syringomyelia-Chiari complex who underwent posterior fossa decompression or syringosubarachnoid shunting were studied clinically and by magnetic resonance (MR) imaging to assess the changes in the syrinx and in their clinical picture after surgery. When symptoms of posterior fossa compression were present, posterior fossa decompression was performed; however, when symptoms of posterior fossa compression were absent, the choice of posterior fossa decompression or syringosubarachnoid shunting depended, respectively, on whether the syrinx was narrow or wide on MR imaging. At least 1 year after surgery, subjective improvement or arrest of disease was recorded in 73% of the patients. The present study suggests that: 1) the symptoms attributed to spinal cord damage have no significant relationship to the size of the syrinx on MR images; 2) the surgical techniques employed in this series (posterior fossa decompression or syringosubarachnoid shunt) were equally useful in inducing syrinx collapse; and 3) when posterior fossa decompression is performed, plugging of the obex is not necessary for syrinx collapse.
Increased CSF neopterin levels in subarachnoid hemorrhage
Authors: Mathiesen Tiit , Fuchs Dietmar , Wachter Helmut , Holst Hans von
Published: May 2009

✓ Neopterin concentrations, reflecting T-cell macrophage activation, were analyzed in serum and cerebrospinal fluid (CSF) obtained from 14 patients with subarachnoid hemorrhage (SAH). Neopterin concentrations were elevated in both the serum and CSF. The increase in neopterin concentrations was most marked in the CSF, rising from Days 1 to 3 through Days 6 to 9; levels were highest in patient suffering from delayed cerebral ischemia. The present data were interpreted as signs of an ongoing T cell activation both systemically and in the CSF compartment following SAH.
Corpus callosal atrophy following closed head injury: detection with magnetic resonance imaging
Authors: Levin Harvey S. , Williams David H. , Valastro Michael , Eisenberg Howard M. , Crofford Marsha J. , Handel Stanley F.
Published: May 2009

✓ To investigate evidence for diffuse white matter injury and hemispheric disconnection sequelae after severe closed head injury (CHI), this study evaluates the degree of posttraumatic atrophy of the corpus callosum. Corpus callosal atrophy was quantitatively determined using a digitizer to measure sagittal magnetic resonance images of 32 patients with moderate-to-severe CHI and those of 31 control subjects of similar age. In the CHI patients, measurements were significantly reduced for the areas of the anterior four-fifths, the posterior one-fifth, and the total corpus callosum. Moreover, the minimum width of the callosal body was reduced in the CHI patients as compared to that of control individuals. Indices of corpus callosal atrophy were significantly correlated with the chronicity of injury and the degree of lateral ventricular enlargement. There was no difference in callosal measurements between men and women. Magnetic resonance imaging provides an in vivo determination of corpus callosal atrophy which may reflect the severity of diffuse axonal injury and predict the type and severity of hemispheric disconnection effects.
Effect of horbol esters on the susceptibility of aglioma cell line to lymphokine-activated killer cell activity
Authors: Maleci Alberto , Alterman Ron L. , Sundstrom David , Kornblith Paul L. , Moskal Joseph R.
Published: May 2009

✓ The mechanisms by which lymphokine-activated killer (LAK) cells exert their cytotoxic effects are not well understood. This study demonstrates that phorbol ester pretreatment of a LAK cell-sensitive glioma cell line (SNB-19) induced a significant decrease in the susceptibility of cells to LAK cell-mediated lysis. This effect was produced by low concentrations of the tumor-promoting phorbol ester, phorbol-12,13-myristate acetate (PMA), and was reversible. Protein kinase C (PKC) inhibitors failed to block this phenomenon. No apparent alteration in the ability of LAK cells to bind to their targets was observed. Thus, PMA may have exerted its effects by a mechanism that does not require PKC, or these glioma cells may possess an isozyme of PKC which is insensitive to the inhibitors used in these studies.
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.
Metastatic intracranial carcinoid with immunohistochemical observation
Authors: Ozawa Tsunenori , Terabayashi Tadasu , Takahashi Hitoshi , Takeda Norio , Ito Yasushi , Saito Akihiko , Sugiyama Yoshiaki , Ikuta Fusahiro
Published: May 2009

✓ A case of metastatic carcinoid tumor in the right occipital lobe originating from a primary tumor in the right colon is reported in a 68-year-old man. The tumor had a high bromodeoxyuridine labeling index. Although immunohistochemical studies of the tumor specimen showed positive reactivity for serotonin and somatostatin, blood levels of serotonin and urinary 5-hydroxyindoleacetic acid content were normal. This suggests that coexistence of somatostatin with serotonin in the tumor tissue might lead to inhibition of serotonin release by “autocrine regulation.” The neurological complications of carcinoid tumors, including intracranial metastasis, are discussed briefly.
Cerebral sparganosis
Authors: Mitchell Andrew , Scheithauer Bernd W. , Kelly Patrick J. , Forbes Glenn S. , Rosenblatt Jon E.
Published: May 2009

✓ The tapeworm Spirometra mansonoides infects man worldwide, particularly in Asian countries. Rarely, the central nervous system is involved; such a case is presented here. In the total of 12 reported cases, including the case described, the worm presented clinically as a mass suspicious for neoplasm or chronic abscess cavity. Surgical removal was invariably curative in each case. Although infrequent, the possibility of tapeworm infection should be entertained in the evaluation of intracranial masses in patients who have visited exotic locales.
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.
Secretion of α2-macroglobulin, α2-antiplasmin, and plasminogen activator inhibitor-1 by glioblastoma multiforme in primary organ culture
Authors: Keohane Mary E. , Hall Scott W. , VandenBerg Scott R. , Gonias Steven L.
Published: May 2009

✓ Explants from a glioblastoma multiforme were maintained for 4 weeks in a three-dimensional Gelfoam matrix culture in order to study the synthesis of α2-antiplasmin (α2AP), α2-macroglobulin (α2M), plasminogen activator inhibitor-1 (PAI-1), and tissue plasminogen activator (t-PA). Since the organ culture system promotes cellular differentiation in gliomas with increasing time in vitro, secretion of the proteinase inhibitors and t-PA was examined at weekly intervals. Increased immunohistochemical staining for glial fibrillary acidic protein, a marker of astroglial differentiation, was observed in the explants with advancing time in culture. The proteinase inhibitors α2AP and α2M were secreted into the medium in all 4 weeks, while PAI-1 was detected at significant concentrations by an enzyme-linked immunosorbent assay (ELISA) in Weeks 3 and 4 only. The quantity of each inhibitor secreted into fresh medium during a 24-hour interval increased with the age of the tumor explants in the Gelfoam culture system. At no time was a sensitive ELISA able to detect t-PA in the culture medium. This study demonstrates that glioblastoma multiforme cells in primary organ culture can secrete three major fibrinolysis proteinase inhibitors. The appearance of PAI-1 only after extensive culturing of the explants suggests a possible correlation with neoplastic astroglial maturation.
Stable xenon-enhanced CT measurement of cerebral blood flow in reversible focal ischemia in baboons
Authors: Yonas Howard , Gur David , Claassen Diana , Wolfson Sidney K. , Moossy John
Published: May 2009

✓ When the lateral striate arteries of the baboon are temporarily occluded for either 20 or 60 minutes, a near-cessation of blood flow is followed by a dramatic, transient local increase in blood flow values. These findings are evident from serial xenon (Xe)-computerized tomography (CT) measurement of cerebral blood flow (CBF). In this study, 20 minutes of vessel occlusion resulted in brief (< 1 hour) hyperemia, with no subsequent CT alteration and minimal random neuronal injury. Sixty minutes of occlusion resulted in a more prolonged hyperemia, a low-density area on CT images within 3 hours of reperfusion, and infarction of all cellular elements within the anterior lentiform nucleus. The Xe-CT method provides a sensitive, noninvasive technique for examining sequential alterations of CBF in small regions deep within the brain. This method of recording CBF also permits correlative studies of cerebral infarction, both clinically and experimentally, and allows reasonable inference about the probabilities of neuronal tissue damage with or without reperfusion.
Changes in the components and content of biological water in the brain of experimental hydrocephalic rabbits
Authors: Tamaki Norihiko , Yamashita Haruo , Kimura Mitsuru , Ehara Kazumasa , Asada Masahiro , Nagashima Tatsuya , Matsumoto Satoshi , Hashimoto Masao
Published: May 2009

✓ Changes in biological water components and their respective content in the cortical gray matter and periventricular white matter were studied in rabbits rendered hydrocephalic by intracisternal kaolin injection. There was no change in either total water content or free or bound water content in the cortical gray matter at the various stages of hydrocephalus development. While there was no significant change in total water content in the periventricular white matter at any stage of hydrocephalus, free water content was significantly elevated and bound water content was decreased at the acute and subacute stages, with a return to relatively normal levels at the chronic stage. It is concluded that in the periventricular white matter, free water enters the brain across the ependymal lining during the acute and subacute stages of experimental hydrocephalus with a simultaneous reduction in the bound water and that there is some recovery at the chronic stage. It is suggested that alternative drainage pathways may develop in chronic hydrocephalus allowing drainage of free water in the periventricular white matter, which in turn permits bound water to return to relatively normal levels.
Cervical myelopathy in diffuse idiopathic skeletal hyperostosis
Authors: Stechison Michael T. , Tator Charles H.
Published: May 2009

✓ The case of a rapidly progressive cervical myelopathy in a 64-year-old man is presented. Radiological studies revealed a partial extradural block, which at surgery was found to be a focal fibrous, calcified mass associated with the ligamentum flavum. On the basis of the underlying disorder of diffuse idiopathic skeletal hyperostosis (DISH), the etiology of this compression was concluded to be focal fibrous proliferation and dystrophic calcification. The neurological complications of DISH are reviewed. The authors are not aware of any other reports of this cause of myelopathy associated with DISH.
Implantation metastasis of pineoblastoma after stereotactic biopsy
Authors: Rosenfeld Jeffrey V. , Murphy Michael A. , Chow Chung W.
Published: May 2009

✓ A case is reported of implantation metastasis occurring 2 months after stereotactic biopsy of a pineoblastoma was performed in an 18-month-old child. Although implantation metastasis is well recognized after needle biopsy of solid tumors, it has not been described following stereotactic biopsy of a brain tumor. Implications for the role of stereotactic biopsy in the management of brain tumors is discussed.
Vilhelm Magnus — pioneer neurosurgeon
Authors: Fodstad Harald , Ljunggren Bengt , Kristiansen Kristian
Published: May 2009

✓ In parallel with but completely independent from Harvey Cushing, Norway had its own giant in the establishment of the special field of neurological surgery. Vilhelm Magnus (1871–1929), born in the United States in Fillmore County, Minnesota, was Norway's pioneering neurosurgeon. Following graduation in Oslo, he started his clinical training in neurology and became an early member of the small group of neurologists of the time who were dissatisfied with the therapeutic nihilism generally accepted in relation to diseases of the nervous system. After working with Victor Horsley, whom he held in high esteem, Magnus devoted himself to surgically treatable lesions in the nervous system. During a quarter of a century he single-handedly established the special field of neurological surgery in Norway. Magnus was a far-seeing and brilliant surgeon with a broad intellectual mind, a startling diligence, and wide research activities. He published his first scientific paper in 1899 and his total contribution to the literature amounted to 70 papers. In 1901 he was able to demonstrate the importance of the corpus luteum in the first 3 weeks of pregnancy. As early as 1903 Magnus manifested his interest in the surgical treatment of brain tumors. In 1926 his surgical material comprised 216 patients, with an 8% operative mortality rate among 161 cases of supratentorial tumor versus 17% for 55 cases of infratentorial tumors, including 14 cases of acoustic tumor. Vilhelm Magnus, who visited Harvey Cushing in 1928, has hitherto not been given the attention he merits.
Presentation and management of suprasellar arachnoid cysts
Authors: Pierre-Kahn Alain , Capelle Laurent , Brauner Raja , Sainte-Rose Christian , Renier Dominique , Rappaport Raphaël , Hirsch Jean-François
Published: May 2009

✓ The clinical presentation and treatment of suprasellar arachnoid cysts remain controversial. The authors review 20 cases treated at their institution and 86 cases from the literature reported in sufficient detail for analysis. The high frequency of endocrinological disorders, which not only persist following treatment but may also develop years later despite the satisfactory decrease in volume of the cyst, are emphasized and documented. The difficulties of management are discussed, including: subfrontal approaches to these cysts; removal and/or marsupialization of the cysts, procedures that are frequently dangerous and ineffective; and ventricular shunting which often leads to a paradoxical increase in the size of the cysts. The authors emphasize the advantages of percutaneous ventriculocystostomy, which is a simple, benign, and efficacious procedure.
Leptomyelolipoma: analysis of 20 cases
Authors: Harrison Michael J. , Mitnick Robin J. , Rosenblum Bruce R. , Rothman Allen S.
Published: May 2009

✓ Leptomyelolipoma (lumbosacral lipoma) is a common form of spinal dysraphism. The deficits produced include sensory, motor, bowel, and bladder dysfunction, and vary in incidence between the pediatric and adult populations. Twenty patients treated surgically at the Mount Sinai Hospital between 1972 and 1988 are reviewed. Fifty percent were 12 years of age or less and 50% were older than 18 years of age. The surgical approach was designed to accomplish untethering of the conus medullaris, debulking of the lipomatous mass compressing the cord, reconstruction of the dural canal, and reapproximation of the paraspinal muscles and lumbosacral fascia to prevent future trauma. Postoperatively, no patient experienced deterioration of neurological function. Of the symptomatic patients, 67% displayed dramatic improvement or became asymptomatic and 33% experienced stabilization of their deficits. The symptoms most resistant to surgical correction were orthopedic foot deformities and bowel dysfunction, whereas bladder dysfunction, motor weakness, and radiculopathies were most amenable to surgical therapy. Early surgical repair is recommended in these cases to forestall irreversible neurological damage.
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.