摘要:

OVER THE LAST decade, much has been learned about the genetic changes that occur in human neoplasia and how they contribute to the neoplastic state. Oncogenes and tumor suppressor genes have been identified, and many powerful molecular genetic techniques have emerged. Brain tumors have been intensively studied as part of this process. Specific and recurring genetic alterations have been identified and are associated with specific tumor types. In astrocytomas, for example, losses of genetic material on chromosomes 10 and 17 and amplification of the epidermal growth factor receptor gene seem important in pathogenesis, with the loss of chromosome 10 and the amplification of epidermal growth factor receptor being strongly associated with glioblastoma multiforme. Meningiomas, on the other hand, have usually lost part or all of chromosome 22. Brain tumors also express growth factors and growth factor receptors that may be important in promoting tumor growth and angiogenesis. These include epidermal growth factor, transforming growth factor-α, platelet-derived growth factor, the fibroblast growth factors, and vascular endothelial growth factor. In this article, we review the genetic aberrations that occur in the major types of brain tumors, including glial tumors, meningiomas, acoustic neuromas, medulloblastomas, primitive neuroectodermal tumors, and pituitary tumors. Wherever possible, clinical correlations have been made concerning the prognostic and therapeutic implications of specific aberrations. We also provide some background about the cytogenetic and molecular genetic techniques that have contributed to the description and understanding of these alterations and speculate as to some clinical and basic science issues that might be explored in the future.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

A CAUSAL RELATIONSHIP between sex steroids and meningioma proliferation has long been suspected. We report a case of the clinical progression of a sphenoid wing meningioma after the placement of Norplant, a subcutaneous contraceptive implant containing levonorgestrel, a progesterone agonist. Although not proof of causation, this observation lends further credence to the importance of progesterone receptors in the growth and possible treatment of meningiomas.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

A 26-YEAR-OLD MAN presented with an unusual multilobulated cystic formation in the brain stem with normal pressure hydrocephalus, followed by fluctuating cyst volume and Benedikt's syndrome. Ventriculoperitoneal shunting to relieve the hydrocephalus caused an increased cystic size, resulting in worsened neurological deficits. Cystectomy and an additional shunt resolved the symptoms. Immunohistochemical and electron microscopic examinations of the surgical specimen revealed no epithelial lining but numerous astrocytic processes on the luminal surface, probably resulting from expansion of the cyst. This case suggests that cystectomy before shunt emplacement is recommended in similar cases.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

A PATIENT WHO sustained a gunshot wound to the head was successfully treated with acute neurosurgical intervention. Six months after the injury, cranioplasty was used to repair a large skull defect. After cranioplasty, the patient developed significant improvement in motor function in his left upper extremity, which had been plegic after his injury. Although the mechanism of neurological recovery after cranioplasty is controversial, the occurrence of such improvement may be a sufficient indication for cranioplasty in certain patients.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

A CASE OF familial polymorphous oligodendroglioma, occurring in a brother and sister, is presented. Polymorphous oligodendrogliomas have a characteristic histopathology consisting of scattered multinucleated giant cells against a typical oligodendroglial background. The oligodendroglial character of the tumors was underlined by positive immunostaining for antigalactocerebroside, anticarbonic anhydrase, and anti-leu-7, without expression of glial fibrillary acidic protein. Both tumors were immunopositive for p53, suggesting a mutation in the p53 gene. No incidence of cancer was recorded in the family. This is the first report of familial occurrence of this particular subtype of oligodendroglioma.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

A 28-YEAR-OLD WOMAN with prior neurosurgery involving the placement of a cadaveric dural graft developed a rapidly progressive neurodegenerative disorder with prominent cerebellar dysfunction that was proven at autopsy to be Creutzfeldt-Jakob disease. She represents the second American to develop Creutzfeldt-Jakob disease in association with a dural graft. The unusual features of the case include the patient's initial clinical presentation with cerebellar ataxia in the absence of dementia, the widespread presence of kuru-type amyloid plaques on a histological examination of the brain, the development of clinical symptoms during pregnancy, and the subsequent delivery of a child who remains healthy at the age of 3 years.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

WE REPORT A case of Creutzfeldt-Jakob disease developing in a 31-year-old woman 56 months after she received a cadaveric dura mater graft after the removal of a giant pituitary adenoma. Creutzfeldt-Jakob disease was confirmed by a brain autopsy and the existence of an abnormal isoform of prion protein, verified by both immunohistochemical and Western blot analysis. Moreover, prion protein gene analysis was shown in this case to possess a wild-type genotype. The characteristics of Creutzfeldt-Jakob disease after a cadaveric dura mater graft are reviewed and discussed.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

WE REPORT A case of a large cavernous sinus aneurysm, in which conventional angiography did not clearly demonstrate the exact form and the position of the neck. Superselective angiography performed with the catheter tip in the lumen of the aneurysm and with the internal carotid artery occluded just proximal to its neck is a new technique that demonstrates the morphological details of an entire aneurysm. With the use of cineangiography, the exact volume of the aneurysm was defined. The valuable aneurysmographic information obtained was useful in achieving occlusion of the aneurysm, while preserving the parent artery.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

ARTERIOVENOUS MALFORMATION AT the cervicomedullary junction is a rare disorder, usually presenting with subarachnoid hemorrhage. The diagnosis is difficult because of its anatomical location. In addition, the ventral location of these arteriovenous malformations makes surgical treatment difficult. We describe three cases surgically treated with a transcondylar approach. The usefulness of digital subtraction angiography and magnetic resonance imaging is discussed. The technique of the transcondylar approach is also described, including C1 hemilaminectomy, unroofing of the transverse foramen of C1 to obtain control of the vertebral artery, and partial resection of the occipital condyle and lateral atlantal mass by extradural drilling. This approach provides direct access to the ventral portion of the cervicomedullary junction.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

WE HAVE RECENTLY introduced a new type of ultrasonic-based, three-dimensional ranging system for the localization of small handheld surgical tools to be used during operation in open stereotactic brain surgery. This targeting system has now been extensively laboratory tested during thousands of measuring cycles with a CNC-based measuring table. The typical accuracy found in a single direction was 0.4 mm and better. The accuracy vector in space was 0.897 mm (n = 2312). The test-retest accuracy was typically 0.4 mm. With the given accuracy, the system is suitable for all ranging tasks in open stereotactically guided microsurgery.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID