Neurosurgery
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The authors review the surgical management of nine complex paraclinoid aneurysms treated with the endovascular balloon catheter technique. With the patient under general anesthesia, the balloon catheter was guided into the feeding artery of the aneurysm by the Seldinger technique. After the aneurysm was exposed, the balloon was inflated temporarily to prevent premature rupture and to facilitate the dissection of the aneurysm. ⋯ An embolectomy was performed immediately, and there were no postoperative sequelae. We conclude that the combined endovascular and neurosurgical approach, particularly for the large ICA aneurysms, which are difficult to control proximally, can be a useful method of treatment. To prevent complications related to thrombus formation, further refinement in the balloon catheter itself is still needed.
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Proliferation and proto-oncogene expression in 19 meningiomas of typical and atypical histology were analyzed in an attempt to understand the mechanism of growth that characterizes the neoplastic process in these tumors. Proliferation was estimated as the proliferative index by the enumeration of S-phase cells in imprints of tumor tissue exposed to bromodeoxyuridine in vitro, and the gene expression of c-myc, c-fos, c-src, c-H-ras, N-myc, acidic and basic fibroblast growth factor, insulin-like growth factors I and II, platelet-derived growth factor-alpha, and epidermal growth factor was quantified by messenger ribonucleic acid dot-blot hybridization assay. Atypical and malignant tumors had significantly higher proliferative indexes than did their nonmalignant counterparts. ⋯ Positive correlations between proliferation and proto-oncogene/growth factor expression were found for c-myc in atypical/malignant tumors and for epidermal growth factor in fibroblastic meningiomas. Deregulated expression of c-myc and c-fos common to both typical and atypical tumors suggests that these are early events in the meningioma tumor process that may disturb the control of cell differentiation and together with fibroblast growth factors are likely to endow the transformed cell with a selective growth advantage by reducing the requirement for exogenous mitogens and by providing a niche for the growth of the tumor clone. Positive correlation of c-myc levels with proliferation in atypical/malignant meningiomas implies that this is a feature of malignancy and indicates continued disruption of the negative regulation of proto-oncogene expression, perhaps by tumor suppressor gene losses, during the course of tumor progression.
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The surgical anatomy of the temporal branch of the facial nerve was studied bilaterally in 10 embalmed cadaveric heads. Particular attention was paid to the relationships between the temporal branch, the galeal-fascial layers, and the fat pads of the temporal-zygomatic region. The temporal branch of the facial nerve pierces the parotidomasseteric fascia below the zygomatic arch. ⋯ Occasionally, a twig for the frontalis muscle may run in between the two layers of the superficial temporal fascia. Because of these findings (anteroposterior variability of temporal branch twigs and recurrent intrafascial twig), Yasargil's interfascial dissection may at times fail. A combined frontotemporal scalp/superficial temporal fascia dissection is anatomically suited to preserve the temporal branch of the facial nerve.
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This report presents a brief overview of the medical and ethical issues involved with the procurement, preparation, safety, efficacy, and subject protection of human fetal central nervous system tissue in the context of neural transplantation. The ethical perspectives from which to view the clinical use of fetal tissue include the following: 1) that fetal tissue from elective abortions is a surgical specimen; 2) that the use of such tissue involves fetal experimentation in which the fetus is a subject; and 3) that fetal tissue is considered as a cadaveric organ specimen, similar to other organs, but with special considerations compared with adult cadaveric tissue. ⋯ Additional issues include the following: 1) the safety and quality of fetal tissue for implantation; 2) the hypothesis that "legitimization" and "redemption" (potentially positive effects of tissue donation in general) may lead to an increase in elective abortion rates; 3) the ethical issues of the validity and value of human experimentation involving neural grafting; and 4) the type of consent to be obtained and the appropriate timing. Elective abortions, however, probably will continue to be the primary source of fetal tissue for grafting for some time, until other tissue sources become available.