摘要:

BETWEEN JANUARY 1990 and February 1992, a total of 301 patients underwent discectomy for lumbar disc herniation; 29 had an extreme lateral herniation, i.e., foraminal or extraforaminal. The intervertebral foramen is a three-dimensional area demarcated primarily by the pedicles; we call it the lateral interpedicular compartment. The extraforaminal zone is the space outside the lateral border of the pedicles. All patients were evaluated by computed tomography (CT), water soluble myelography, postmyelographic CT scanning, or magnetic resonance imaging. Fifteen patients consecutively underwent disco-enhanced CT to adjust a correct diagnosis and to distinguish extraforaminal from foraminal herniation. In 10 cases of extraforaminal herniation, a selective radicular decompression with good-to-excellent clinical results was achieved by an extra-axial lateral decompression of the interpedicular compartment, with preservation of the facet joint. The operative target was the lateral aspect of the pars interarticularis and not the intertransverse space, as previously described. In two cases of both foraminal and extraforaminal herniation, the same technique was used. Fourteen patients with foraminal disc herniation and three patients with both foraminal and extraforaminal herniation underwent a standard intervertebral foraminotomy. An accurate preoperative diagnosis established by disco-CT is crucial in order to select the most suitable surgical approach.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

NEOPLASTIC MENINGITIS DUE to the dissemination of systemic cancer or primary central nervous system tumors through the cerebrospinal fluid carries a very poor prognosis. Current treatments for this disease are ineffective, and new therapeutic modalities such as immunotoxins may be beneficial. We created an animal model of human carcinomatous meningitis with LOX melanoma-derived tissue-culture cells in athymic rats for testing the efficacy of intrathecal therapy with transferrin-Pseudomonasexotoxin A (Tfn-PE) immunotoxin. An injection of 5 × 105LOX cells into the intrathecal space through an indwelling catheter resulted in the reproducible development of lower-extremity paraplegia at 9.24 ± 1.77 days because of focal deposits of tumor growth adjacent to the thoracic and lumbar spinal cord. A dose of 2.5 or 5 μg of intrathecal Tfn-PE immunotoxin was neurotoxic and resulted in the deaths of 8 of 10 animals within 24 hours. Histological evidence of central nervous system damage was seen as hemorrhagic degeneration around the central canal or a pathological cleft at the level of the cervical spinal cord. Because no neurotoxicity was seen with 1 μg of intrathecal Tfn-PE immunotoxin, this dose was administered in treatment experiments. Twenty-four hours after the intrathecal instillation of LOX cells, 10 animals received intrathecally either 1 μg of Tfn-PE or phosphate-buffered saline with 0.1% human serum albumin (control group). Control animals experienced lower-extremity paraplegia at 10.7 ± 2.75 days compared with animals treated with Tfn-PE, which did not develop paralysis until 15.5 ± 4.58 days, representing a mean delay in the onset of paraplegia of 5 days or 31% (P= 0.015). This observed delay in the onset of paraplegia in treated animals with human neoplastic meningitis supports the use of intrathecal immunotoxins for Phase I/II clinical trials in patients with carcinomatous meningitis from systemic or central nervous system cancer.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

HUMAN GLIOBLASTOMA (U-87MG) and canine glioma (canine brain tumor [CBT]) cell lines were tested in vitro for their therapeutic sensitivity to sequential treatment with differentiating agents and chemotherapy or hyperthermia. Both cell lines responded to the inducer combination dibutyryl adenosine-3′,5′-cyclic monophosphate/sodium butyrate by the formation of cytoplasmic processes detectable within 7 hours and attained approximately 90% morphological differentiation within 2 days of exposure. The clonogenicity of CBT and U-87MG cells gradually decreased after 1 to 7 days of exposure to the inducer combination, but this treatment alone failed to kill the cells. After the removal of the inducers, both lines dedifferentiated and the rate of clonogenesis increased. 1,3-bis-(2-Chloroethyl)-1-nitrosourea administered to CBT and U-87MG cells before or after 3 days of treatment with inducers potentiated the antiproliferative effects of the differentiating agents. Cisplatin administered to U-87MG cells enhanced the antiproliferative effect of the differentiating agents to a greater extent when added before the inducers rather than after differentiation was stimulated. The sequential treatment of CBT cells with a 44°C heat pulse for 30 minutes followed by differentiating agents produced an additive potentiation of cell killing, whereas the reverse sequence did not. Hyperthermia pretreatment at 44°C for 15 minutes or at 42°C for 30 minutes failed to enhance the antiproliferative effects of inducing agents. Pretreatment at 44°C for 30 minutes enhanced the antiproliferative effects of inducers by 23%, whereas 46°C for 30 minutes potentiated cell killing by 38%. This study demonstrates that nontoxic differentiation therapy can potentiate the therapeutic effects of chemotherapy in glial brain tumors and can thereby reduce the concentration of cytotoxic drugs required to achieve effective cell killing. Hyperthermia can be used to potentiate the effects of differentiating agents.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

METHOTREXATE (MTX) ALONE has a limited effect against malignant brain tumors, but we previously demonstrated a beneficial synergism between MTX and radiation therapy (XRT) against RT-9 gliosarcoma. Because the beneficial effects of that study were limited by systemic toxicity and poor brain penetration of MTX, we have continued our studies using direct intracerebral MTX therapy. Male CD-Fisher rats with intracerebrally implanted RT-9 gliosarcoma and indwelling brain tumor catheters were treated with intracerebral injections of MTX, whole-brain XRT, or a combination of both. MTX was given either as one of two “high-dose” treatments, on the basis of whole-body doses, or two “low-doses,” on the basis of average brain weight. MTX alone at lower doses and XRT alone each prolonged survival moderately. High-dose MTX was highly toxic, but low-dose MTX was well tolerated. Combined MTX and XRT caused a significant prolongation of survival in all animals that survived treatment long enough to die from tumor growth.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

DEREGULATION OF THE expression of cytokine genes appears to play a role in the development of gliomas. Interleukin-1β has been shown to be synthesized in small amounts by astrocytes and can induce the expression of interleukin-6. Interleukin-6 is not expressed by unstimulated astrocytes, but the deregulation of its expression has been implicated in the progression of several tumor types. In this study, tumor specimens from 16 brain tumors and 22 glioma cell lines were studied for the gene expression of both interleukin-1β and interleukin-6, and the coexpression of these two cytokines was found in a significant number of these specimens. The expression of these two growth factor genes may play an important role in the growth and development of human gliomas.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

HISTOLOGICAL GRADING OF fibrillary astrocytic neoplasms has proved to be a valuable prognostic tool, but potentially could benefit from more objective data, such as estimates of proliferative rate. The authors have investigated the prognostic utility of quantitative Ki-67 immunoreactivity in a prospective survival analysis of 36 adult patients with astrocytoma, anaplastic astrocytoma, or glioblastoma multiforme diagnosed between 1987 and 1992. A digital image analyzer was used to assay proliferation indices (PIs) in surgical biopsy specimens obtained at first diagnosis (32 of 36) or at a second biopsy of histologically unchanged high-grade disease (4 of 36). A Ki-67 PI of ≥7.5% was associated with higher histological grade and poorer survival, and the Ki-67 PI was more significantly related to survival (P< 0.001) than histological grade as determined by a modified Ringertz grading system (P= 0.002). Survival analysis within histological grades suggested that astrocytoma patients with PI ≥ 3% may be at increased risk for shorter survival than those with PI < 3%.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

FLOW CYTOMETRY WAS used to determine the deoxyribonucleic acid ploidy and proliferative activity of 60 oligodendrogliomas and oligoastrocytomas. The relationships among survival, ploidy, proliferation, histological features, and clinical variables were analyzed. Survival was strongly associated with the S-phase fraction (P< 0.001). Three groups with significantly different survival rates were defined, based on S-phase fraction ranges of < 3%, 3 to 5.9%, and > 6%. Significant associations between survival and age at diagnosis (P< 0.001), tumor grade (P< 0.001), and extent of surgery (P< 0.01) were found also. The poor correlation between mitotic figures and survival in oligodendrogliomas that has been reported previously emphasizes the need for an accurate method to measure proliferative activity. Our study demonstrated the usefulness of the flow cytometry-determined S-phase fraction in this regard and demonstrated that specific reference ranges could be defined for clinical application. In contrast, the determination of ploidy by flow cytometry was not useful in the evaluation of oligodendrogliomas.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

THE MONITORING OF auditory function by recording brain stem auditory evoked potentials in patients undergoing removal of acoustic tumors is hampered by the small amplitude of the brain stem auditory evoked potentials. Because several thousands of responses must be added, it takes several minutes to obtain an interpretable record. Recordings done directly from the exposed eighth nerve have much higher amplitudes, and, therefore, interpretable responses can be obtained after only a few responses have been added. However, it is difficult to place the recording electrode in an optimal position and the electrode may interfere with the removal of the tumor. In this report, we show that evoked potentials from the cochlear nucleus, which can be recorded by placing an electrode in the lateral recess of the fourth ventricle, have a large amplitude, and that the electrode placed in this way does not interfere with the removal of the tumor. This way of monitoring, therefore, yields interpretable responses within 15 to 20 seconds, or less, and makes it possible to detect injuries to the entire intracranial portion of the eighth nerve, just as brain stem auditory evoked potentials do, but 20 to 50 times faster.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

CELLULOSE ACETATE POLYMER solution is a liquid thrombotic material that hardens into the shape of an aneurysm into which it is injected. Therapy using this solution is a rapid technique that helps prevent the rupture of aneurysms, especially those that extravasate contrast material during angiography in the acute stage of subarachnoid hemorrhage. Using this polymer solution and an endovascular technique, we treated two patients who had aneurysms of the basilar and anterior communicating arteries with extravasation of contrast material during angiography a few hours after the initial subarachnoid hemorrhage. In one patient with an aneurysm of the anterior communicating artery, the aneurysm's wall was perforated with the catheter during neurointerventional procedures. In both patients, postoperative angiograms demonstrated obliteration of the aneurysmal dome, including the site of extravasation or perforation. The parent artery and surrounding perforating branches were preserved. Although we do not advocate aggressive therapy for patients who bleed during angiography, we pursued this therapy in these two patients because of the opportunity to introduce cellulose acetate polymer in an attempt to preserve the patients' lives. Unfortunately, both patients died. Histopathological studies performed at the time of autopsy demonstrated that the luminal surface of cellulose acetate polymer was covered with thrombus by 6 days after cellulose acetate polymer thrombosis. By 10 days, the thrombus had a prominent fibrin network, a concentrated plasma component, and few fibrocytes adhering to its luminal surface. The clinical description and results of treatment and histopathological studies are presented here.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

A SET OF standard techniques to monitor the motor and sensory function of the cauda equina is proposed for surgery in the lumbosacral spinal canal for the release of a tethered cord or the removal of a neoplasm. Continuous loudspeaker-controlled recording of electromyographic activity in four leg muscles of both sides supplied the surgeon with immediate feedback on injury to any of the motor roots from the second lumbar to the fourth sacral segment. Continuous recording of tibial nerve somatosensory evoked potentials yielded information about the functional state of parts of the lumbosacral sensory pathways. Motor roots could be identified by electrical stimulation in the operating field with bipolar stimulation forceps and recording of compound muscle action potentials from the leg muscles. Sensory nerve roots could be identified by nerve root somatosensory evoked potentials recorded from the scalp after the electrical stimulation of the exposed nerve. This set-up is a combination of previously developed monitoring techniques and provides the surgeon with functional information: 1) continuous feedback on the state of the endangered motor and sensory function of the cauda equina; and 2) rapid anatomical identification of nerve roots and their distinction from fibrous or neoplastic structures.

ISSN:0148-396X    

出版商:OVID    

年代:1994

数据来源: OVID