A number of signaling pathways can be constitutively activated in migrating glioma cells, thus rendering these cells resistant to cytotoxic insults. However, these pathways are not all constitutively activated at the same time in any one glioma. Particular inhibitors should therefore only be chosen if the target is present in the tumor tissue, but this is only possible if individual patients are submitted to the molecular profiling of their tumors before undergoing any treatment to combat their migratory glioma cells. Specific antimigratory compounds should be added to conventional radio- and/or chemotherapy.

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Complete resection of the increased PET tracer uptake prolongs the survival of HGG patients. Because PET information represents a more specific marker than MRI enhancement for detecting anaplastic tumor tissue, PET-guidance increases the amount of anaplastic tissue removed in HGG.

We conclude that radical surgical resection of spinal cord ependymomas can be safely achieved in the majority of patients. A trend toward neurological improvement from a postoperative deficit can be expected between 1 and 3 months after surgery and continues up to 1 year. Postoperative dysesthesias begin to improve within 1 month of surgery and are significantly better by 1 year after surgery. The best predictor of outcome is the preoperative neurological status.

Various regions of the brain have been successfully transduced by recombinant adeno-associated virus (rAAV) vectors with no detected toxicity. When using the cytomegalovirus immediate early (CMV) promoter, a gradual decline in the number of transduced cells has been described. In contrast, the use of cellular promoters such as the neuron-specific enolase promoter or hybrid promoters such as the chicken beta-actin/CMV promoter resulted in sustained transgene expression. The cellular tropism of rAAV-mediated gene transfer in the central nervous system (CNS) varies depending on the serotype used. Serotype 2 vectors preferentially transduce neurons whereas rAAV5 and rAAV1 transduce both neurons and glial cells. Recombinant AAV4-mediated gene transfer was inefficient in neurons and glial cells of the striatum (the only structure tested so far) but efficient in ependymal cells. No inflammatory response has been described following rAAV2 administration to the brain. In contrast, antibodies to AAV2 capsid and transgene product were elicited but no reduction of transgene expression was observed and readministration of vector without loss of efficiency was possible from 3 months after the first injection. Based on the success of pioneer work performed with marker genes, various strategies for therapeutic gene delivery were designed. These include enzyme replacement in lysosomal storage diseases, Canavan disease and Parkinson's disease; delivery of neuroprotective factors in Parkinson's disease, Huntington disease, Alzheimer's disease, amyotrophic lateral sclerosis, ischemia and spinal cord injury; as well as modulation of neurotransmission in epilepsy and Parkinson's disease. Several of these strategies have demonstrated promising results in relevant animal models. However, their implementation in the clinics will probably require a tight regulation and a specific targeting of therapeutic gene expression which still demands further developments of the vectors.

Galectins, a family of mammalian lectins with specificity to ␤-galactosides, are involved in growthregulatory mechanisms and cell adhesion. A relationship is assumed to exist between the levels of expression of galectins and the level of malignancy in human gliomas. A comparative study of this aspect in the same series of clinical samples is required to prove this hypothesis. Using computerassisted microscopy, we quantitatively characterized by immunohistochemistry the levels of expression of galectins-1, -3 and -8 in 116 human astrocytic tumors of grades I to IV. Extent of transcription of galectins-1, -3, and -8 genes was investigated in 8 human glioblastoma cell lines by means of RT-PCR techniques. Three of these cell lines were grafted into the brains of nude mice in order to characterize in vivo the galectins-1, -3 and -8 expression in relation to the patterns of the tumor invasion of the brain. The role of galectin-1, -3 and -8 in tumor astrocyte migration was quantitatively determined in vitro by means of computer-assisted phase-contrast videomicroscopy. The data indicate that the levels of galectin-1 and galectin-3 expression significantly change during the progression of malignancy in human astrocytic tumors, while that of galectin-8 remains unchanged. These three galectins are involved in tumor astrocyte invasion of the brain parenchyma since their levels of expression are higher in the invasive parts of xenografted glioblastomas than in their less invasive parts. Galectin-3, galectin-1, and to a lesser extent galectin-8, markedly stimulate glioblastoma cell migration in vitro. Since bands for the transcripts of human galectins-2, -4 and -9 were apparently less frequent and intense in the 8 human glioblastoma cell lines, this system provides an excellent model to assign defined roles to individual galectins and delineate overlapping and distinct functional aspects.

To optimize pain control and minimize complications of this therapy, we recommend that the nerve be targeted at a distance of 5 to 8 mm from the brainstem.

The authors report a series of 34 meningiomas of the sphenoid ridge. Eight tumors were totally removed uneventfully: two from the middle sphenoid ridge and six from the pterion or Sylvian point. Five tumors were not operated on because of their extensions or the patient's age. Twenty-one tumors raised serious surgical problems, resulting in a classification into three groups: deep or clinoidal, invading beyond the sphenoid wings, and a combination of both. Histological study of the hyperostotic bone showed meningiomatous cells in the bone in 12 of 13 cases so examined. Surgical limitations included invasion of the cavernous sinus (15 cases), of the dura mater of the sella turcica (seven cases), of the lateral part of the sphenoid body at the insertion point of the ala magna (seven cases), and of the common tendinous annulus of Zinn in the orbit (five cases), and basilar extracranial extension, particularly in the pterygomaxillary fossa (three cases). Following extensive removal, there were no early recurrences and three late recurrences (9 years and more). In 13 cases with a follow-up period of 1 to 8 years, there were no clinical recurrences. In only two cases was the meningioma totally removed. There were three postoperative deaths, two cases of hemiparesis with aphasia and epilepsy, one case with a frontal lobe syndrome, and nine with slight oculomotor, visual, or esthetic sequelae.