[Orbital invasion of a maxillary ameloblastoma]

A 66-year-old man with a history of repeated surgery, external radiation and brachytherapy for ameloblastoma presented with a recurrence of the tumor with sinus, intraorbital and skull base infiltration. Histopathologic examination of the resected orbital and sinus tissue confirmed the diagnosis of ameloblastoma. Immunohistochemical staining for CD56 was strongly positive in the tumor cells. Although ameloblastoma is usually a low-grade malignant tumor, it can be locally aggressive with invasion of the surrounding tissue. Maxillary ameloblastomas are more likely to infiltrate the orbit.

Basic fibroblastic growth factor as a potential meningeal angiogenic factor

Vascular supply plays a significant role in the management of skull base tumors. The diagnosis is aided by contrast-enhanced imaging and angiographic techniques, and embolization procedures are used to devascularize certain lesions. The degree of surgical technical difficulty is strongly influenced by the degree of tumor vascularity. Although the importance of this blood supply is clearly understood, the mechanism involved in developing a system of tumor-perfusing vessels is yet to be defined. The development of a vascular network, or angiogenesis, is an important event in allowing tumor proliferation to progress beyond small clusters of cells. Basic fibroblastic growth factor (bFGF) is an especially attractive candidate as an angiogenic growth factor because of its ability to stimulate processes that are characteristic of angiogenesis in vitro. Tumors that involve the meninges may have the ability to liberate normally stored bFGF, which may, in turn, induce new vessel formation for continued tumor proliferation. An immunohistochemical analysis of rodent and bovine meninges to study this phenomenon is described. The dura, arachnoid, and their associated vessels are shown clearly to contain this growth factor. Ultimately, an adjuvant therapy based on the inhibition of angiogenesis may provide a reasonable alternative to aggressive surgical approaches in skull base tumors that are incompletely resectable.

Differences in the distribution of methotrexate into high grade gliomas following intravenous administration, as monitored by microdialysis, are associated with blood brain barrier integrity

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Background: Microdialysis (MD) is an accepted technique to monitor neurochemicals in pts with traumatic brain injury. This study was conducted to evaluate the use of MD to define the time course of intratumoral drug concentrations in pts with high grade gliomas (HGG) receiving systemic chemotherapy. Methods: MD catheters were placed in residual HGG following tumor debulking and infused with Ringer’s solution at 1 μL/min. MD probe location and integrity of the blood brain barrier (BBB) in adjacent tissue were determined by fused MRI/CT. Highdose (12g/m2) methotrexate (MTX), was given as a 4 h iv infusion the next day. MTX was measured in plasma and dialysate samples, collected at 30 min intervals from 1 h before to 24 h after dosing, with an LC/MS assay. Results: Six pts have been enrolled without any adverse events attributed to the MD catheter. Adequate pharmacokinetics (PK) were obtained in 4/6pts. MTX plasma pharmacokinetics (PK) were very consistent between the 4 evaluable pts and similar to published data. Time courses of the uncorrected MTX concentration in extracellular fluid (CECF) exhibited two distinctly different kinetic profiles. For 2pts in whom the MD probe resided within contrast enhancing tumor, CECF increased and decreased in parallel with drug levels in plasma, with a peak CECF of 189 ± 6 μM, an apparent elimination half-life in ECF of 4.44 ± 0.07 h, and an ECF/plasma AUCratio of 0.13 ± 0.01. The other 2pts had a much lower peak CECF (10.4 ± 0.4 μM) and AUC ratio (0.028 ± 0.020), with a more prolonged ECF half-life (11.4 ± 4.5 h). Fused images from 2 of these pts showed that the MD probe was located in nonenhancing tissue. Conclusions: MD is a clinically practical technique to monitor the distribution of systemically administered drugs to brain tumors in pts. It has the capability to elucidate variations in kinetic behavior that are consistent with regional differences in BBB integrity. Appropriate interpretation of data from MD studies to evaluate the distribution of investigational new drugs into brain tumors necessarily requires radiographic determination of the region of the tumor into which the probe has been placed.

No significant financial relationships to disclose.

Phase I analysis of systemic interferon alpha utilized with gliadel in adults with recurrent glioblastoma multiforme (GBM)

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Background: Local therapy with Gliadel was found to increases median survival at recurrence from 23 to 31 weeks when compared to placebo wafers. Brain tumor specimens have been observed to have a 40–50% rate of deletion of the IFNα interferon a gene. Previous clinical studies have demonstrated response rates to IFN-α in the range of 0–41% in the treatment of recurrent primary malignant glioma, either alone, or in combination with other modalities. This study assess the safety and toxicity of Interferon α-2b (IFN-α) and 3.85% BCNU-permeated wafers (Gliadel®). Methods: This is a phase I dose escalation assessment of the toxicity of IFN-α utilized in conjunction with Gliadel® in patients with recurrent GBM, who failed previous radiation and chemotherapy. Ten patients were enrolled in this dose escalation trial. Three dose levels were studied were with the starting dosage of was IFN-α 3 Mu/m2 (n = 3), 6 Mu/m2 (n = 3) and 9 Mu/m2 (n = 4) subcutaneously injection 3 times a week for a total period of 8 weeks with the first dose being initiated 1 week following craniotomy and Gliadel placement. Results: There were 10 patients, 5 males and 5 females with a median age of 46 yrs (range 35–55). At re-operation, all histology revealed 10 GBM. At dose 3 Mu/m2, 2/3 pts developed grade 2 fatigue, myalgia and depression, but completed treatment with 1 PR (109 + wks) and 1 CR (91 + wks) and 1 PD (6 wks). Another patient was off study because of progressive disease (PD). At dose 6 Mu/m2, all 3 had PD with 2 pts having Grade 2 received a dose reduction because of diarrhea and 1 patient withdrawing early for PD finished only 1 cycle (4 wks). At dose 9 Mu/m2, 2 patients developed grade 3 toxicity fatigue/malaise and one patient completed therapy with dose reduction and but progressed, another patient stopped treatment after first 3 doses due to progression. There were overall response of 20% (1 PR and 1 CR) with duration of 109+ and 91+ wks. Clinical response with IFNα gene is being analyzed. Conclusions: This study defined MTD at 6 Mu/m2 with a DLT at 9 Mu/m2 and recommended a Phase II dose in this population. Since interestingly, the responses occurred at the lowest dose, suggesting a portion of the effect may be anti-angiogenic in nature.

No significant financial relationships to disclose.

Effectiveness of oral or nebulized dexamethasone for children with mild croup

OBJECTIVE

To assess the efficacy of oral dexamethasone or nebulized dexamethasone sodium phosphate in children with mild croup.

METHODS

Double-blind, placebo-controlled study of 264 children between 6 months and 6 years of age with symptoms of croup for fewer than 48 hours. Patients were excluded if they received racemic epinephrine or corticosteroid treatment. Other exclusion criteria included corticosteroid treatment during the 14 days prior to enrollment or complicating medical condition. Subjects randomly received oral dexamethasone (0.6 mg/kg), nebulized dexamethasone sodium phosphate (160 microg), or placebo. Telephone follow-up was obtained on days 1, 2, 3, 4, and 7.

MAIN OUTCOME MEASURES

The primary outcome measure was treatment failure, defined as receiving corticosteroid or racemic epinephrine treatment during the 7 days after enrollment in the study. Secondary outcome measures included seeking additional care and the parental assessments of the patients' condition obtained during follow-up (worse, same, better, or gone).

RESULTS

Eighty-five patients received oral dexamethasone, 91 received nebulized dexamethasone, and 88 received placebo. There were 3 treatment failures in the oral dexamethasone-treated group, 12 in the nebulized dexamethasone-treated group, and 10 in the placebo-treated group (P =.05). Ten children in the oral dexamethasone-treated group sought additional care compared with 27 and 29 in the nebulized dexamethasone-treated and placebo-treated groups, respectively (P =.002). Parents of children in the oral dexamethasone-treated group reported greater improvement on day 1 (P<.001) compared with the nebulized dexamethasone-treated and placebo-treated groups.

CONCLUSIONS

Children with mild croup who receive oral dexamethasone treatment are less likely to seek subsequent medical care and demonstrate more rapid symptom resolution compared with children who receive nebulized dexamethasone or placebo treatment.

Stereotactic radiosurgery of malignant and benign intracranial lesions utilizing a patient rotator

This study examines the characteristics of the patient groups, treatment parameters, and results of therapy for 126 intracranial lesions treated with stereotactic radiosurgery utilizing a "patient rotator" and a linear accelerator. A retrospective review was conducted and data on 122 patients (21 patients with arteriovenous malformations-AVMs, 40 patients with 41 metastatic tumors, 24 patients with malignant gliomas and 37 patients with other benign lesions) were analyzed. Clinical and radiographic response was obtained from chart review and/or telephone follow-up. The average follow-up was 12.1, 13.0, 5.7, and 23.1 months in patients with AVMs, malignant gliomas, metastases, and other lesions, respectively. Median survival times (MST) of the metastatic and glioma group were 9 and 38 months, respectively. Complete or partial radiographic response at follow-up was seen in 62.5% of AVM patients, 33.3% of patients with metastases, 11.8% of patients with malignant gliomas, and 19.3% of patients with other lesions. (1) Local control of brain metastases and benign intracranial lesions can be obtained with single dose stereotactic radiosurgery. (2) The MST and local control rate for metastatic disease obtained are comparable with those in the literature. (3) The patient rotator method for stereotactic radiosurgery is an effective tool for treating selected intracranial lesions.

Extraneural metastatic glioblastoma after interstitial brachytherapy

PURPOSE

This is a report of 3 cases of extraneural metastasis of glioblastoma after interstitial radiation and assessment of pertinent literature addressing concern over an increased risk of these events with this therapy.

METHODS AND MATERIALS

In a series of 82 patients treated with (125)I brachytherapy for primary malignant brain tumors over a 7-year interval, 3 cases of extraneural glioblastoma were identified. The multicatheter technique for delivery of (125)I sources was utilized in all. Extraneural metastases were documented by imaging studies or biopsy. Over the same period, 310 patients with primary malignant brain tumors were treated without brachytherapy.

RESULTS

Biopsy-proven scalp and skull metastases occurred in 2 patients, at 3 and 8 months following brachytherapy. Each developed radiographic evidence of systemic metastases at 7 and 14 months postbrachytherapy, respectively. The third patient developed biopsy-proven cervical node involvement 4 months after brachytherapy. No patients with malignant gliomas undergoing craniotomy or stereotactic biopsy, but not brachytherapy, during the same time period developed extraneural metastases. Incidence in previously reported series commenting on this otherwise rare process range from 0% to 4.3%. The incidence of extraneural metastases in this series is 3.7% (3/82) and is comparable to those reports.

CONCLUSIONS

Percutaneous catheter-delivered brachytherapy may be associated with an increased incidence of extraneural metastatic glioma.

Neurosurgical advances in the treatment of brain tumors

Surgery remains an important part of the treatment of primary malignant brain tumors. When surgery is utilized, care must be taken to maximize the safety of the procedures. This article emphasizes advances in lesion localization within the brain and technology used to identify the function of normal tissue around the tumor. Many of the new treatment paradigms involve a surgical procedure. For example, surgery is necessary for biodegradable treatment delivery systems, and for some focal radiation therapy. Neurosurgeons are familiar with implantable catheter systems for other types of disease such as hydrocephalus; however, there is now an opportunity to take advantage of such technology to assist in the delivery of treatment agents locally within a tumor. Although no specific surgical advance has offered cure of malignant tumors, surgery remains necessary for utilization of the treatment advances now becoming available.

Cloning of neuronal mtDNA variants in cultured cells by synaptosome fusion with mtDNA-less cells

Synaptosome cybrids were used to confirm the presence of heteroplasmic mtDNA sequence variants in the human brain. Synaptosomes contain one to several mitochondria, and when fused to mtDNA-deficient (rho degrees ) mouse or human cell lines result in viable cybrid cell lines. The brain origin of mouse synaptosome cybrid mtDNAs was confirmed using sequence polymorphisms in the mtDNA COIII, ND3 and tRNA(Arg)genes. The brain origin of the human synaptosome cybrids was confirmed using a rare mtDNA Mbo I polymorphism. Fusion of synaptosomes from the brain of a 35-year-old woman resulted in 71 synaptosome cybrids. Sequencing the mtDNA control region of these cybrid clones revealed differences in the number of Cs in a poly C track between nucleotide pairs (nps) 301 and 309. Three percent of the cybrid clones had mtDNAs with 10 Cs, 76% had nine, 18% had eight and 3% had seven Cs. Comparable results were obtained by PCR amplification, cloning and sequencing of mtDNA control regions directly from the patient's brain tissue, but not when the control region was amplified and cloned from a synaptosome cybrid homoplasmic for a mtDNA with nine Cs. Thus, we have clonally recovered mtDNA control region length variants from an adult human brain without recourse to PCR, and established the variant mtDNAs within living cultured cells. This confirms that some mtDNA heteroplasmy can exist in human neurons, and provides the opportunity to study its functional significance.

Intracranial extraskeletal mesenchymal chondrosarcoma: case report

OBJECTIVE AND IMPORTANCE

We present a patient with a dural-based intracranial extraskeletal mesenchymal chondrosarcoma, which was initially thought to be an atypical meningioma. This rare tumor should be considered in the differential diagnosis of young adults with an aggressive-appearing dural-based lesion.

CLINICAL PRESENTATION

A 21-year-old woman reported a 3-week history of severe headaches and intermittent nausea and vomiting. Neurological examination revealed right optic nerve swelling. Magnetic resonance imaging demonstrated a large, intensely enhancing extra-axial mass, which appeared to originate from the right side of the falx cerebri with significant mass effect. A presumptive diagnosis of meningioma was made.

INTERVENTION

The patient underwent preoperative embolization of the lesion and then underwent a bicoronal craniotomy, gross total resection of the tumor, removal of invaded calvarial bone, and cranioplasty. Pathological examination revealed an extraskeletal mesenchymal chondrosarcoma. Because of the potential for recurrence, the patient received subsequent radiotherapy. She remains free of recurrence 18 months after surgery.

CONCLUSION

Intracranial mesenchymal chondrosarcoma is a rare neoplasm that can mimic a meningioma radiographically. We present the first patient in whom this lesion has been documented with computed tomography, cardiography, magnetic resonance imaging, and pathological findings. We emphasize the importance of gross total resection and close follow-up for this potentially aggressive tumor, and we present a review of the literature.

Tumor suppressor gene alterations in malignant gliomas: histopathological associations and prognostic evaluation

We have examined a series of 135 gliomas for alterations of the p53, CDKN2A (p16) and PTEN tumor suppressor genes (TSGs) in order to evaluate the incidence of their inactivation as a function of tumor malignancy and cellular differentiation, and to examine potential associations with patient outcome. The composition of this series, classified using WHO criteria, is as follows: 27 grade 2 tumors (11 astrocytomas, 12 oligoastrocytomas, 4 oligodendrogliomas), 42 grade 3 tumors (22 astrocytomas, 16 oligoastrocytomas, 4 oligodendrogliomas), and 66 grade 4 tumors (63 astrocytomas and 3 oligoastrocytomas). Similar frequencies of p53 mutation were observed among grade 2 (37.0%), and grade 3 tumors (38.1%), as well as between astrocytomas and mixed tumors. CDKN2A and PTEN mutations were clearly associated with increasing tumor malignancy (occurring in 0% of grade 2 tumors, 14.3% and 4.8% respectively of grade 3 tumors, and 27.3% and 30.3% respectively of grade 4 tumors) and were observed at substantially higher rates among astrocytomas. For the tumor suppressor genes examined, there was no relationship between the occurrence of any two TSG inactivation events. With regard to outcome, the p53 genetic status showed no significant relationship with patient survival. The CDKN2 and PTEN alterations were negative prognostic indicators of survival when evaluated in all 135 gliomas, but failed to predict outcome when evaluated in either of the high grade (3 or 4) tumor groups.

Analysis of cyclin dependent kinase inhibitors in malignant astrocytomas

The cyclin-dependent kinase inhibitors p16, p21, and p27 in human brain, and brain tumors were examined to explore clinicopathologic correlations. Western analysis and immunohistochemistry was performed and correlated retrospectively with the patients clinical characteristics. A trend was found between increased progression-free survival and p27 expression. There was no correlation between p27 expression and age or gender. The expression of p27 in malignant gliomas may have prognostic value. In addition, an investigation of the therapeutic benefit of overexpression of this cyclin-dependent kinase inhibitor is warranted given reports of diminished malignant potential of tumors expressing p27.

Lipomatous glioneurocytoma of the posterior fossa with divergent differentiation: case report

OBJECTIVE AND IMPORTANCE

We report a case of a posterior fossa neuroepithelial tumor with unusual clinical presentation, magnetic resonance imaging appearance, and morphological features.

CLINICAL PRESENTATION

This 66-year-old man presented with a history of gait ataxia, dizziness, and tinnitus and was found to have a large tumor in the posterior fossa and cerebellopontine angle.

INTERVENTION

Gross total excision of the tumor was accomplished. Histologically, the most unique features were macrovesicular accumulations of lipid, giving the tumor (at least focally) an appearance virtually identical to that of mature adipose tissue. Evidence of biphasic neuronal and glial differentiation was noted by immunohistochemistry and electron microscopy.

CONCLUSION

A literature review is presented. Diagnostically, this neoplasm seems to fit in a unique group of rarely described, lipomatous neuroectodermal tumors that show divergent neuronal and glial differentiation.

Gene amplification as a prognostic factor in primary brain tumors

The most reliable prognostic factors for patients with primary malignant brain tumors remain histology, age, and functional status. Management of these individuals might be improved by quantifying pertinent molecular markers. We have measured the gene dosage of the epidermal growth factor receptor (EGFR), mouse double minute 2 (MDM2), and cyclin-dependent kinase 4 (CDK4) genes in a series of brain tumor specimens and correlated their amplification status with standard prognostic factors and survival. Individual tumor DNA was successively hybridized with probes for EGFR, MDM2, and CDK4. The signal was quantified by densitometry, and amplification was defined as gene signal > or = 2 times normal. Survival, age, Karnofsky performance status, and histology were correlated with gene amplification. Nineteen astrocytomas, 20 anaplastic astrocytomas, and 70 glioblastomas had complete data available. Median survival with and without any form of gene amplification was 70.7 and 88.6 weeks, respectively (P = 0.0369). For the EGFR gene alone, those with and without amplification had a median survival of 58.9 and 88.6 weeks, respectively (P = 0.0104). By Cox analysis, only tumor histology (P = 0.04) and Karnofsky performance status (P = 0.0157) were significant independent predictors of survival. Gene amplification by itself was not predictive of survival, even for glioblastomas (P = 0.8249). The lack of correlation between gene amplification and survival for patients with primary malignant brain tumors may be because EGFR, MDM2, and CDK4 are only portions of larger signaling systems. Therefore, the lack of a direct correlation between a single gene and outcome is not entirely unexpected.

Transfection of IFNalpha in human glioblastoma cells and tumorigenicity in association with induction of PKR and OAS gene expression

Previously these authors and others demonstrated frequent homozygous deletions of the chromosome 9p-localized class I interferon (IFN) gene cluster in glioblastoma tumors and cell lines. To investigate the biological effects of class I IFN gene transfer and constitutive expression in glioblastoma cells devoid of this gene cluster, the authors have developed a stable IFNalpha "transfectant" of the cell line U118. The expression of IFNalpha protein in the U118 transfectant clone is associated with decreased levels of DNA synthesis exhibited by cultures of transfected cells, reduced colony-forming ability in soft agar, and loss of tumorigenicity in athymic nude mice. To address the molecular consequences of constitutive IFNalpha synthesis, they examined the expression of four genes whose transcription has been shown to be responsive to IFN-mediated signal transduction and could be important to the observed antiproliferative and antitumor effects. Northern blot analysis revealed that changes in the levels of messenger (m)RNA for two of these genes, c-myc and mhc class I, are minor. However, mRNAs for oligoadenylate synthetase (OAS) as well as double-stranded RNA-activated protein kinase (PKR), which are not expressed in parental U118 cells, were constitutively expressed in IFNalpha transfectants. These results indicate a differential responsiveness among these four genes to constitutive IFNalpha expression, and suggest that the suppression of U118-transformed phenotypes by IFNalpha transfection may be mediated by the induction of specific IFN response genes thought to have a negative growth-regulatory function.

Molecular genetics and molecular biology advances in brain tumors

As the genes that regulate cell growth and proliferation are being identified and their encoded proteins characterized, our understanding of the molecular basis of tumor development is expanding rapidly. This review focuses on recent studies examining alterations of growth-regulatory genes in brain tumors, including those involving the inactivation of gene products that normally suppress cell growth (tumor-suppressor genes) or those involving the activation of gene products that promote cell growth (oncogenes) and presents information concerning the molecular biology associated with these changes.

Intra-arterial cisplatin in malignant brain tumors: incidence and severity of otic toxicity

Intra-arterial (IA) cisplatin is used to treat gliomas with the goal of maximizing drug concentration in the brain while minimizing systemic toxicity. The present study is based on the author's experience with IA cisplatin administration in 12 patients. The primary goal of the study was to document the extent of otic toxicity in these individuals. Hearing was tested clinically and with audiograms, before each IA cisplatin injection. Eight women and four men with a mean age of 39 1/2 years (range 22-61) were treated. Diagnoses included 7 glioblastoma multiformes, 4 anaplastic astrocytomas, and 1 gliosarcoma. Diagnosis was obtained by stereotactic biopsy in four and craniotomy for resection and debulking in eight. The mean number of IA injections per patient was 4.58 (range 3-6). The cisplatin dose was 60 mg/m2 with the average dose of cisplatin per cycle being 116 mg (range 96-130 mg). Eleven patients had the agent administered via the internal carotid and one received it by way of a vertebral artery. Nine of the twelve patients (75%) demonstrated pure tone loss, as measured by audiography, of greater than 15 dB in the higher frequencies range (> or = 3 kHz) bilaterally. One patient became deaf and two others had clinically significant hearing loss. The severity of the auditory damage increased after each administration in each of the cases with clinical abnormality. IA cisplatin may have a role in the treatment of patients with primary malignant brain tumors, but further developments to limit otic toxicity would be of value.

Lack of p16INK4 or retinoblastoma protein (pRb), or amplification-associated overexpression of cdk4 is observed in distinct subsets of malignant glial tumors and cell lines

In this study the expression of p16INK4, retinoblastoma protein (pRb), and cdk4 proteins have been examined in 18 malignant glioma cell lines and in 45 malignant glial tumors. Loss of p16INK4 expression associated with p16INK4 gene homozygous deletion was evident in 12 cell lines and in 10 primary tumors. Lack of p16INK4 expression was also evident in five tumors for which there was no evidence of p16INK4 gene homozygous deletion. Two of the cell lines and six of the primary tumors in which p16INK4 was present were determined to overexpress cdk4 in association with CDK4 gene amplification. Absence of pRb was determined in two of the cell lines and in ten of the tumors. In total, 16 of 18 cell lines and 25 of 45 tumors showed either a lack of p16INK4 or pRb or amplification-associated overexpression of cdk4. Two additional tumors showed an absence of pRb and p16INK4, and one tumor showed a lack of pRb combined with amplification-associated overexpression of cdk4. These results suggest a common growth-regulatory mechanism that is disrupted in gliomas by either suppressing the expression of p16INK4 or pRb or by increasing the expression of cdk4.

Loss of vertical palpebral fissure height on downgaze in acquired blepharoptosis

OBJECTIVE

To determine criteria to diagnose and document functional visual impairment from upper eyelid ptosis in the downgaze position of reading.

DESIGN

Prospective clinical study.

PATIENTS

From September 1991 to June 1992, 47 consecutive patients with adult-onset acquired ptosis were enrolled in the study. Downgaze eyelid and relative brow position were evaluated in 88 eyelids of these patients.

INTERVENTIONS

Surgical repair of blepharoptosis by the Müller muscle conjunctival resection ptosis procedure, levator aponeurosis advancement and/or resection, or levator muscle resection.

MAIN OUTCOME MEASURE

Postoperative change in the eyelid and brow position in downgaze.

RESULTS

Of all ptotic eyelids, 43% had zero vertical palpebral fissure height in downgaze when the brows were relaxed and therefore were functionally blind in the downgaze position. After ptosis repair, there was a significant widening of the vertical palpebral fissure height in downgaze (P < .001), a significant decrease in frontalis muscle use (P < .001), and return of the patients' ability to sustain downgaze function.

CONCLUSIONS

Measurement of palpebral fissure height in downgaze and frontalis muscle use in patients with acquired ptosis identifies patients with a functional visual deficit in the downgaze reading position. These measurements can be easily performed in the office and may be added to criteria for documenting functional impairment from blepharoptosis.

Metastatic follicular thyroid carcinoma masquerading as a chordoma

A 61-year-old Caucasian man presented with otalgia, dysarthria, and weight loss. Neurological examination revealed palatal hypomotility, and weakness of the facial and tongue muscles. Magnetic resonance imaging of the head demonstrated the presence of a soft tissue mass in the clivus. Histologic examination of resected tumor disclosed well-differentiated thyroid follicles that invaded the local osseous tissues. Physical examination and radioiodine images of the thyroid gland were normal. The serum thyroglobulin concentration was markedly elevated (1011 ng/mL). A 0.9-cm well-differentiated benign-appearing left thyroid lobe follicular neoplasm with a thick fibrous capsule was found following diagnostic thyroidectomy. This report illustrates that clinically significant distant metastases can arise from occult follicular thyroid neoplasms that, according to standard histologic criteria, are benign. The presence of a thick fibrous capsule, even in the absence of vascular or capsular invasion, may identify follicular neoplasms that have metastatic potential.

Analysis of epidermal growth factor receptor gene amplification and alteration in stereotactic biopsies of brain tumors

In recent years, results from molecular-based investigations of central nervous system neoplasms have indicated that the occurrence of specific genetic alterations correlates with tumor malignancy and clinical behavior. One such example is epidermal growth factor receptor gene amplification and alteration in association with tumors histologically classified as glioblastoma multiforme. As our understanding of the implications of these changes develops, detection of epidermal growth factor receptor alteration and amplification may have diagnostic, prognostic, and ultimately, therapeutic value. The goal of this communication is to demonstrate the usefulness of stereotactic specimens for molecular genetic analysis, in this case, the analysis of the epidermal growth factor receptor gene for amplification and alterations. The techniques used here will maximize the number of cases from which useful information can be obtained. Properly adapted, the value of these techniques for expanding our understanding of these lesions is enormous.

Isolation and culture of bovine intracranial arterial endothelial cells

We report a simple explant technique to isolate and propagate endothelial cells from bovine cerebral arteries. The endothelial nature of the cells was confirmed by the presence of Factor VIII/von Willebrand antigen, the ability to phagocytize low-density lipoprotein, and the ability to be induced to express E-selectin. The lack of expression of the CD11c antigen and the absence of smooth muscle alpha-actin immunofluorescence suggested that the cultures were not contaminated with macrophages or smooth muscle cells, respectively. This technique yields pure cerebral arterial endothelial cell cultures, which will be of value for in vitro investigation of cerebrovascular physiology and disease processes.

Low-grade astrocytomas arising from the pineal gland

Two cases of low-grade astrocytoma arising from the pineal gland are described in this report. These rare lesions have only been reported on two previous occasions to arise distinctly from the pineal gland. Histologically, one tumor was consistent with a juvenile pilocytic astrocytoma, while the other was consistent with a fibrillary astrocytoma. The pathological features, clinical implications, and treatment of low-grade astrocytomas in the pineal region are discussed.

Reliability of differential PCR for the detection of EGFR and MDM2 gene amplification in DNA extracted from FFPE glioma tissue

A series of 43 human gliomas, consisting of 30 glioblastomas, 7 anaplastic astrocytomas, 3 low grade astrocytomas, 2 ependymomas, and 1 oligodendroglioma, was studied for amplification of the epidermal growth factor receptor (EGFR) and mouse double minute 2 (MDM2) genes. DNA extracted from formalin-fixed, paraffin-embedded tissue sections was analyzed by differential PCR and the results were compared with slot blot examination of DNA extracted from frozen tissue from the same neoplasms. Twelve glioblastomas (40%) showed amplification of the EGFR gene, and overexpression of EGFR was evident in each of these tumors as indicated by the immunoperoxidase technique. Two of the tumors with EGFR gene amplification also revealed amplification of the MDM2 gene, while one additional glioblastoma revealed MDM2 amplification only. A 100% concordance in the detection of amplification was observed between differential PCR and slot blot analysis; consequently, these results indicate that differential PCR using DNA extracted from archival tissue sections is a reliable method of demonstrating gene amplifications in glial tumors.

In vitro interaction of cisplatin and fosfomycin on squamous cell carcinoma cultures

OBJECTIVE

Fosfomycin has been shown to be otoprotective and nephroprotective against cisplatin-induced toxic reactions. This study tests whether fosfomycin inhibits the anticancer effect of cisplatin.

METHODS

Three squamous cell carcinoma cell lines were used to determine the effect of fosfomycin on cisplatin-induced tumoricidal activity. Cells were grown in 96 well plates with fosfomycin alone, cisplatin alone, or fosfomycin and cisplatin together. Cell survival was then measured by a colorimetric technique using 3-4,5-dimethylthiazol-2-yl 2,5 diphenyltetrazolium bromide (MTT).

RESULTS

There was no decrease in the effectiveness of cisplatin in killing human squamous cell carcinoma in vitro when fosfomycin was present in concentrations of up to 400 mg/L. One cell line also showed killing at high concentrations of cisplatin, but not at low concentrations.

CONCLUSIONS

Fosfomycin protects against cisplatin-induced toxic reactions and does not inhibit tumoricidal activity in vitro. In addition, one cell line showed relative resistance to cisplatin at low doses, but was effectively killed with high doses of cisplatin. This is the ideal situation for use of fosfomycin so that higher doses of cisplatin may be given with renal and otologic protection.

Functional characterization of an EGF receptor with a truncated extracellular domain expressed in glioblastomas with EGFR gene amplification

The most common type of alteration of the epidermal growth factor receptor gene (EGFR) in human glioblastomas results in the synthesis of an aberrant mRNA lacking 801 bases that encode amino acids 6-273 of the receptor's extracellular domain. To study the effects of this mutation on receptor function, we have developed chinese hamster ovary cell transfectants which express the mutant EGF receptor. Comparison of wild-type and mutant receptor properties in this cell host indicates that the truncated receptor does not bind EGF or TGF-alpha and, consequently, DNA synthesis is not stimulated in cultures of mutant transfectants by either grown factor. However, levels of DNA synthesis determined for mutant transfectants in serum-free media are several-fold higher than those determined for corresponding cultures of wild-type transfectants. Western blot analysis with anti-phosphotyrosine antibody indicates that the mutant receptor is constitutively phosphorylated in CHO cells, and the same analysis applied to lysates of glioblastoma biopsies reveals the altered receptor is readily detectable as a phosphotyrosine protein in tumors for which there is evidence of corresponding EGFR gene and transcript alterations. In total, these results indicate that the aberrant EGF receptor synthesized in glioblastomas, and which lacks a portion of the extracellular domain necessary for ligand binding, is an activated tyrosine kinase.

Laboratory evidence for the hormonal dependency of meningiomas

Evidence for the hormonal dependency of meningiomas and of the value of various forms of endocrine therapy are described. Clinical features of the tumour are described. Laboratory evidence for the presence and activity of functional steroid receptors is described, and their characteristics are analysed. The effect of receptor antagonists on the growth of the tumour cells is indicated.

The efficacy and distribution of suramin in the treatment of the 9L gliosarcoma

Suramin inhibits the stimulation of brain tumor deoxyribonucleic acid synthesis in vitro at concentrations of 200 to 400 mg/ml. This report evaluates suramin in the rodent 9L tumor model. Survival was analyzed by treating 10 tumor-bearing animals with suramin (7 mg/kg/d intraperitoneally) for 7 days, beginning 1 week after implantation, and compared with 20 untreated animals. Tissue distribution was analyzed with reverse-phase high-pressure liquid chromatography in homogenized organs of normal animals. Tumor concentration was measured over time in animals treated with a range of suramin doses, beginning 2 weeks after implantation. Suramin imparted no benefit as tumor-bearing control animals and treated animals survived 24.7 +/- 3.4 days and 24.5 +/- 1.5 days, respectively. In the animals receiving 7 mg/kg/d, renal concentrations of suramin were highest--339.8 +/- 30.9 mg/g as late as 25 days after treatment. Concentration in the brain peaked at only 3.3 +/- 1.3 mg/g after 10 days. Concentration in the tumor peaked at 74.4 +/- 16.5 mg/g the day of the last injection, significantly less than estimated by in vitro studies of efficacy. After injections of 35 mg/kg/d, tumor levels reached 230.9 +/- 139.2 mg/g with no evidence of inhibition of tumor progression. The response to a 7 mg/kg direct brain inoculation of suramin was assessed and compared with saline as a control. Animals treated with suramin died after 1 to 3 hours. Intracerebral hematoma volume at the injection site was 13.9 +/- 10.7 mm3 and 1.9 +/- 3.32 mm3 in the suramin-treated and control animals, respectively (P = 0.02), confirming the reported anticoagulant activity of suramin. Suramin is without efficacy in the 9L model because of poor systemic delivery. Alternative direct inoculation results in lethal local hemorrhage. Further consideration is necessary before the broad clinical application of this drug.

Acquired blepharoptosis secondary to essential blepharospasm

We treated four patients with essential blepharospasm, receiving botulinum A toxin, in whom, although they had no preexisting blepharoptosis, a concurrent bilateral acquired blepharoptosis developed. Since the blepharoptosis did not improve after the period of time during which the effects of botulinum A toxin would have been expected to resolve (2 to 10 weeks), we judged that its development was unrelated to the toxin. We propose, rather, that the stretching, attenuation, disinsertion, or dehiscence of the upper eyelid levator muscle caused by the blepharospasm were at least partly responsible for the onset of the blepharoptosis. To ensure appropriate treatment in these cases, careful clinical evaluation is required to differentiate the two conditions.

Composite grafting for eyelid reconstruction

Viable composite grafting is a technique used in eyelid reconstruction in which the graft is obtained from the contralateral eyelid. We reviewed the charts of 51 patients who underwent composite grafting of the eyelid since 1983. The average horizontal length of the defect repaired with this technique was 17.3 mm, and the most common indication for its use was basal cell carcinoma. Postoperatively, 39 (91%) of the 43 patients with available measurements had within 2.0 mm of palpebral fissure symmetry. Furthermore, this method of reconstruction allows survival of the eyelid margin and eyelid margin cilia. Composite grafting of the eyelid is a valuable method for eyelid reconstruction that provides acceptable cosmetic results.

Suramin inhibits growth factor binding and proliferation by urothelial carcinoma cell cultures

Suramin is a polyanionic compound recently noted to inhibit growth factor action and proliferation of several types of neoplastic cells in vitro. Data from clinical trials show antineoplastic activity against some prostatic and adrenal cortical carcinomas. Suramin is excreted unmetabolized into the urine suggesting possible application in treatment of urothelial carcinoma and prompting us to examine the drug's effect on growth factor binding and cell proliferation by two urothelial carcinoma cell lines. Half-maximal inhibition of 125I-epidermal growth factor (EGF) binding to T24 and HT1376 cells was produced by suramin concentration of approximately 300 and 100 microM, respectively. The corresponding value for 125I-insulin-like growth factor 1 (IGF1) binding was 60 microM for both cell lines. Inhibition of T24 and HT1376 growth was virtually complete at suramin concentrations in the range achievable clinically.

Bilateral dacryocystitis after punctal occlusion with thermal cautery

A 61-year-old woman developed acute bilateral dacryocystitis secondary to Staphylococcus aureus 3 weeks after undergoing punctal occlusion with thermal cautery for keratoconjunctivitis sicca. The dacryocystitis resolved with intravenous antibiotics, aspiration of the lacrimal sacs, injection of sulfacetamide into the lacrimal sacs, and bilateral dacryocystorhinostomy. Preexisting bilateral nasolacrimal duct obstruction was postulated as the underlying cause. In these cases, irrigation of the lacrimal system is recommended before proceeding with punctal occlusion.

The cerebral radioprotective effect of alternative barbiturates to pentobarbital

The potential for normal brain tissue injury is one of the limiting factors in the use of radiotherapy for brain tumors. As attempts to enhance brain tumor radiation sensitivity have been unsuccessful, the use of cerebral radioprotectants provides an attractive alternative. Pentobarbital has recently been shown to be a cerebral radioprotectant in the rodent and primate models of single fraction radiation injury. Because daily high doses of pentobarbital bring certain significant risks, the potential usefulness of alternative barbiturates was explored. Seven groups of rats received 70 Gy of whole-brain-only irradiation in the single fraction. Group 1 was treated while awake. Groups 2, 3, and 4 received pentobarbital, thiopental, and methohexital, respectively. Groups 5, 6, and 7 received increasing doses of phenobarbital. Mean group survival at 30 days after treatment was determined and compared with the survival of animals treated while awake. Thiopental enhanced survival, similar to pentobarbital. Methohexital and phenobarbital were of no radioprotective value. The differences in the hypnotic effects of these barbiturates is based on dissimilar effects on the kinetics of chloride ion channel patency. We propose that these differences also influence their radioprotective properties. Thiopental is a shorter acting alternative to pentobarbital for cerebral radioprotection. Use of it should permit safer and easier investigation of this radioprotective effect in human trials.

Conventional frozen sections in periocular basal-cell carcinoma: a review of 236 cases

Two hundred thirty-six periocular basal-cell carcinomas were resected under conventional frozen-section control. Only two tumors recurred, yielding a success rate of 99.2%. The mean follow up was 56 months. Eighty-one of the 236 patients were followed for at least 5 years; the 5-year cure rate was 97.5%. To our knowledge, this is the largest reported series of periocular basal-cell carcinoma resected under conventional frozen-section control; also, we believe the follow-up data are superior to those of previous series. The high success rates with conventional frozen-section techniques in this and other series are comparable to those reported for the Mohs micrographic techniques.

Reduction in radiation-induced brain injury by use of pentobarbital or lidocaine protection

To determine if barbiturates would protect brain at high doses of radiation, survival rates in rats that received whole-brain x-irradiation during pentobarbital- or lidocaine-induced anesthesia were compared with those of control animals that received no medication and of animals anesthetized with ketamine. The animals were shielded so that respiratory and digestive tissues would not be damaged by the radiation. Survival rates in rats that received whole-brain irradiation as a single 7500-rad dose under pentobarbital- or lidocaine-induced anesthesia was increased from between from 0% and 20% to between 45% and 69% over the 40 days of observation compared with the other two groups (p less than 0.007). Ketamine anesthesia provided no protection. There were no notable differential effects upon non-neural tissues, suggesting that pentobarbital afforded protection through modulation of ambient neural activity during radiation exposure. Neural suppression during high-dose cranial irradiation protects brain from acute and early delayed radiation injury. Further development and application of this knowledge may reduce the incidence of radiation toxicity of the central nervous system (CNS) and may permit the safe use of otherwise "unsafe" doses of radiation in patients with CNS neoplasms.

Cerebral radioprotection by pentobarbital: dose-response characteristics and association with GABA agonist activity

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.

Enhancement of the efficacy of x-irradiation by pentobarbital in a rodent brain-tumor model

Radiation therapy is an important component of brain tumor treatment, but its efficacy is limited by its toxicity to the surrounding normal tissue. Pentobarbital acts as a cerebral radioprotectant, but the selectivity of its protection for the central nervous system has not been demonstrated. To determine if pentobarbital also protects tumor against ionizing radiation, five groups of Fischer 344 rats were observed after exposure to varying combinations of the presence or absence of implanted tumor, pentobarbital, and radiation treatment. The first three groups underwent cerebral implantations of a suspension of 9L gliosarcoma cells. Group 1 was left untreated and served as tumor-bearing controls. Group 2 received 30 Gy of whole-brain x-irradiation without anesthesia 8 days after tumor implantation. Group 3 received the same radiation treatment 15 minutes after pretreatment with 60 mg/kg of pentobarbital intraperitoneally. Groups 4 and 5 served as radiation controls, receiving 30 Gy of x-irradiation while awake and 30 Gy of x-irradiation after pentobarbital administration, respectively. Survival was calculated from the death of the last tumor-bearing rat. The mean survival time in tumor-bearing control rats was 20.8 +/- 2.6 days (+/- standard deviation). X-irradiation alone significantly enhanced the period of survival in rats implanted with the 9L tumor (29.7 +/- 5.6 days, p less than 0.03). Further significant prolongation of survival was seen with the addition of pentobarbital to the treatment regimen (39.9 +/- 13.5 days, p less than 0.01). Nontumor-bearing rats irradiated while awake (Group 4) survived 30.9 +/- 2.3 days. All of their pentobarbital-anesthetized counterparts in Group 5 survived. If pentobarbital had offered radioprotection to the tumor, then Group 3 would have had a shorter survival period than Group 2. This implies that the enhancement of survival time after irradiation results from selective protection of normal brain in this model.

Androgen receptors in meningiomas

Meningiomas have been hypothesized as being hormonally sensitive on the basis of epidemiologic, clinical, and laboratory evidence. Eight meningiomas were assayed and found to have androgen-binding protein. Three tumors were subjected to in vitro growth studies in varying concentrations of dihydrotestosterone (DHT). The growth of tumor 1 was unaltered. Tumor 2 demonstrated 9% to 10% growth (P less than 0.05) in all concentrations tested. Tumor 3 revealed an 11% stimulation, but only in the lowest concentration of DHT tested. The small quantity, saturability, and in one tumor, high binding affinity, suggest this binding protein is a receptor. The in vitro response of these meningiomas was small and was not dose-related or proportionate to receptor quantity. Androgens do not appear to play as important a role as progesterone or estrogen in meningioma growth in vitro.

Methylprednisolone reduces the bulk flow of water across an in vitro blood-brain barrier

Cerebral water content is a variable quantity subject to the influence of hemodynamic and biochemical factors. Corticosteroids are frequently used in the therapy of cerebral edema, although their mechanisms of action in promoting the resolution of this state of pathologically increased water content remains unclear. To investigate this, a modified Ussing chamber was designed. The bulk flow of media (mainly composed of water) across a monolayer of cultured mouse cerebral endothelia was measured as a control. The same membranes were then exposed to either micromolar concentrations of hydrocortisone or methylprednisolone. The hydraulic conductivity (Lp) of each membrane before and after exposure to the corticosteroids was calculated as a reflection of membrane tightness. Methyl-prednisolone decreased the Lp of the membrane (i.e. tightened) by 36.1% compared to control. Hydrocortisone actually increased Lp (i.e. loosened the membrane) but not to a significant extent. The decrease in the bulk flow caused by methylprednisolone in vitro suggests that the mechanism of the clinically observed decrease in cerebral edema after corticosteroid administration may be due to the reduction of bulk flow across the blood-brain barrier.

The role of new vessels and macrophages in the development and resolution of edema following a cortical freeze lesion in the mouse

The role of an influx of macrophages and neovascularity in the resolution of vasogenic edema is not well defined. The inhibition of these processes with x-irradiation or parenteral corticosteroid administration was used to evaluate their contribution to the resolution of edema around a cortical freeze lesion in mice. The resorption of Evans blue, a marker of protein extravasation, was delayed in x-irradiated mice on the second day following a freeze lesion (p = 0.0075), which correlates with a delay in macrophage infiltration around the lesion. The specific gravity of the lesion and its border regions was significantly less in x-irradiated animals on day 7 than in controls (p = 0.00062), which correlates with a delay in new vessel formation around the lesion. Administration of corticosteroids from the time of production of the freeze lesion resulted in a specific gravity significantly less than control when measured eight days after the lesion (p = 0.01). Macrophages may participate by inhibiting the development of the macromolecular portion of vasogenic edema. The development of neovascularity correlates with the resorption of the aqueous portion of vasogenic edema. As with x-irradiation, corticosteroids administered from the time of freeze lesion inhibited the resorption of the aqueous portion of vasogenic edema, but they may suppress the spread of edema in this experimental model.

Comparative evaluation of intracranial epidermoid tumors with computed tomography and magnetic resonance imaging

The diagnosis of intracranial epidermoid tumors with computed tomography (CT) is often difficult because of indistinct margins, close proximity to the skull base, and a density similar to that of cerebrospinal fluid (CSF). Recent experience with six histologically confirmed epidermoid tumors served to emphasize the value of magnetic resonance (MR) imaging in studying these lesions. MR images were obtained using varying spin echo and inversion recovery techniques with a 0.5-tesla superconducting magnet. CT with and without enhancement had been performed in each case. In Case 1, CT showed an ill-defined left cerebellopontine angle hypodensity. MR imaging clearly showed the presence of abnormal tissue at that location. Case 2 showed a CSF density mass in the right upper posterior fossa. MR imaging of that area showed a variegated signal of a mass extending supratentorially. CT of Case 3 showed a left medial middle fossa hypodensity with an enhancing rim. MR imaging showed a clearly extraaxial mass in that location. In Case 4, a diffuse cerebellar hemispheric hypodensity was observed on CT and was clearly demarcated by MR studies. A huge lesion, thought initially to be an arachnoid cyst on CT of Case 5, was seen on MR imaging to be a large, extraventricular mass displacing the temporal lobe. Finally, CT in Case 6 was suggestive of a poorly demarcated right cerebellopontine angle lesion, which was seen on MR images to be extraaxial, displacing the brain stem. Various MR images more clearly demonstrate the extent of abnormal tissue than CT of epidermoid tumors.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute effect of angiographic contrast medium on cortical specific gravity after middle cerebral artery occlusion in rats

Early angiography after cerebral arterial occlusion has been cited as potentially detrimental. This investigation evaluates the effect of acute angiographic contrast medium administration on the cortical edema induced by middle cerebral artery (MCA) occlusion. Sixteen rats underwent MCA occlusion, and after 1 hour half the rats underwent ipsilateral internal carotid injection of meglumine diatrizoate, whereas the remainder underwent cervical internal carotid exposure only. Six rats had only sham operations on the MCA and internal carotid, and 4 other rats served as normal controls. Cortical specific gravity was measured to reflect cerebral edema 4 hours after occlusion or sham operation. Specific gravity of the lateral frontal cortex in the hemisphere ipsilateral to occlusion was 1.0396 +/- 0.0011 (mean +/- SEM) when no angiographic contrast medium was administered, significantly less (p less than 0.01) than in rats exposed to contrast medium (specific gravity 1.0442 +/- 0.0005). The latter value was not significantly different from normal. Other cortical areas on the side of the contrast medium injection were also relatively dehydrated compared with normal controls. Early meglumine diatrizoate administration after MCA occlusion results in a decrease in cerebral cortical edema, possible by inducing an osmotic gradient that draws water from the extravascular space.