Anti-sense oligonucleotide of p21(waf1/cip1) prevents interleukin 4-mediated elevation of p27(kip1) in low grade astrocytoma cells.

Elevation of the cyclin-dependent kinase (cdk) inhibitor, p27(kip1) is necessary for Interleukin (IL)-4-mediated growth arrest of human low grade astrocytoma (RTLGA) cells and occurs at 24 h of treatment. Pathways involved in IL4 alteration of p27(kip1) are unknown, however. Here we investigated whether other cdk inhibitors contributed to the actions of IL-4 on RTLGA cells. By 12 h of IL-4 treatment, both cdk4 and cdk2 kinase activities against the retinoblastoma protein (pRb) were reduced and nuclear entry of pRb was prohibited. Twelve-hour cdk complexes contained elevated p21(waf1/cip1) but not p27(kip1), p15(ink4B) or p16(ink4A). IL-4 increased p21(waf1/cip1) but not p27(kip1) mRNA levels, and stimulated luciferase activity of a p21(waf1/cip1) promoter-luciferase reporter. In p53-mutant WITG3 cells, IL-4 did not alter p21(waf1/cip1) mRNA and promoter-luciferase activity or p27(kipl) protein, suggesting a need for functional p53. STAT6 phosphorylation by IL-4, however, occurred in both p53-mutant WITG3 and p53-functional RTLGA cells. Pre-treatment of RTLGA with anti-sense but not missense p21(waf1/cip1) oligonucleotide prior to IL-4: (a) restored cdk activities; (b) reduced cdk4-associated p21(waf1/cip1) levels; (c) prevented p27(kipl) elevation; and (d) reversed growth arrest. These results are the first to suggest that p21(waf1/cip1) is essential for IL-4-mediated elevation of p27(kip) and growth arrest of astrocytoma cells.

Astrocyte expression of major histocompatibility complex gene products in multiple sclerosis brain tissue obtained by stereotactic biopsy.

Major histocompatibility complex (MHC) class I and class II antigens were characterized by immunocytochemistry in two chronic-active multiple sclerosis lesions in tissue obtained from two patients by stereotactic biopsy. We examined in particular astrocytic MHC-positive cells in relation to lesion architecture. The MHC class I (HLA-A,B,C)-positive astrocytic cells were widely dispersed, being present at the lesion edge, in the gliotic lesion center, and in normal-appearing white matter as well. Morphologically astrocytic MHC class II (HLA-DR)-positive cells were confined exclusively to the lesion edge. By staining serial sections with antisera to glial-fibrillary acidic protein and HLA-DR, we confirmed the lineage of several MHC class II-positive astrocytes. The demonstration of MHC antigen-positive astrocytes in multiple sclerosis tissue obtained by stereotactic biopsy is novel; the differential distribution of MHC class I- and class II-positive astrocytes in the multiple sclerosis lesion may provide suggestive clues about the regulation of MHC expression on these cells in vivo.

Stereotactic biopsy of an active multiple sclerosis lesion. Immunocytochemical analysis and neuropathologic correlation with magnetic resonance imaging.

Stereotactic biopsy of an active multiple sclerosis lesion in a 23-year-old patient with unilateral symptoms and an isolated high-signal-intensity magnetic resonance abnormality yielded 10 serial tissue cores (1.0 x 0.5 cm) spanning 40 mm within and around the lesion. We performed semiquantitative analysis of lymphocyte phenotype, using antisera to CD3, CD4, CD8, and CD22 molecules, in 11 separate perivascular cuffs in three tissue sections from the lesion edge. Total cells in the cuffs varied from 10 to 100; ratios of CD4+/CD8+ cells in individual cuffs varied from 1.3 to 4.7. Although intense parenchymal infiltrates bordered the least cellular cuffs, parenchymal and perivascular cell phenotypes were indistinguishable, arguing against selective trafficking of lymphocytes into tissue. Individual microfoci of cells displaying CD45RA, CD25, and TQ1 antigens were present. The remarkable phenotypic heterogeneity of T lymphocytes in the multiple sclerosis lesion border is consistent with exposure in situ to a diversity of differentiating stimuli. Histologic demyelination correlated very closely with the signal-intensity abnormality observed on magnetic resonance imaging. These studies provide unusual insight into the histologic and immunocytochemical morphologic appearance of the active multiple sclerosis plaque.

Further observations on the pathology of subcortical lesions identified on magnetic resonance imaging.

We performed postmortem magnetic resonance imaging and pathologic examinations on the brains of seven consecutive patients older than 50 years of age who died of non-neurologic causes. Multiple hyperintense subcortical lesions were identified in each patient, and a total of 29 lesions were examined histologically (eight rims, six caps, six punctate lesions, and nine patches). Rims were characterized by subependymal gliosis and loss of the ependymal lining; caps were associated with myelin pallor, gliosis, and arteriosclerosis; punctate lesions were characterized by dilated perivascular spaces and perivascular gliosis; and patches were associated with myelin pallor and dilated perivascular spaces. The pattern of myelin pallor defined the size and shape of caps and patches. Arteriosclerosis was identified in six of six caps, three of six punctate lesions, and in three of nine patches. These data indicate that (1) each type of hyperintense subcortical lesion has a distinct pathologic correlate; (2) arteriosclerosis is not invariably associated with all types of hyperintense subcortical lesions on magnetic resonance imaging; and (3) myelin pallor appears to contribute to the magnetic resonance imaging signal at 1.5 tesla.

Sclerosing vasculopathy of the central nervous system in nonelderly demented patients.

Three nonelderly patients without hypertension whose clinical and radiologic features otherwise resembled Binswanger's subcortical arteriosclerotic encephalopathy underwent biopsy of the hyperintense periventricular lesions seen on magnetic resonance imaging. The pathologic findings of the periventricular lesions consisted of gliosis with mild rarefaction and edema of the white matter. All patients had a sclerosing vasculopathy of unknown cause, which involved numerous small vessels within the periventricular lesions. The vessels stained negatively for amyloid, amyloid precursors, desmin, vimentin, keratin, immunoglobulin, and complement. On electron microscopy, small arteries, arterioles, venules, and capillaries were characterized by swollen astrocytic foot processes surrounding the vessels; dense, perivascular collagen packing; crystalline arrays of filaments within basement membrane; giant lipid-laden lysosomes within perivascular cells; and narrowing of the vascular lumina. Similar changes were not seen in a control group of 19 patients. The pathologic features of the vessels in these cases are distinct from the vasculopathy associated with Binswanger's subcortical arteriosclerotic encephalopathy. We suggest that a spectrum of vasculopathies may be associated with dementia and periventricular hyperintense lesions on magnetic resonance imaging.

Electrophysiologic pathologic correlations in patients with complex partial seizures.

We studied interictal activity and site of ictal onset in 26 patients with complex partial seizures of temporal lobe origin. All patients had prolonged electrocorticographic recordings from subdural electrode arrays placed both over the convexity and beneath the temporal lobe. We found a significant correlation between the epileptogenic focus and the type of pathologic lesion found at time of surgery. Macroscopic lesions strongly tended to have an epileptogenic focus on the lateral surface of the temporal lobe; patients with only microscopic abnormalities tended to have an epileptogenic focus in the mesial/basal region of the temporal lobe.

Diffusely infiltrating brainstem gliomas: a report of the diagnostic difficulties in 2 cases.

Brainstem gliomas seem to present in 2 distinct ways. More commonly they are localized to 1 portion of the brainstem and present with signs that are both localizing and lateralizing. These are usually fairly easy to image neuroradiologically. The rarer diffusely infiltrating variety manifest a slowly building array of findings pointing to all levels and both sides of the brainstem. Our 2 cases exemplify the diffuse variety. They were clinically typical, and the CSF pressure and protein were elevated but the neuroimaging abnormalities were so subtle that they were originally overlooked. This subtlety of neuroradiologic abnormality resembles that found in gliomatosis cerebri.

Clinical outcome after complete or partial cortical resection for intractable epilepsy.

This is the first epilepsy surgery series to analyze the definition of "completeness" of resection, based solely on results of chronic scalp and subdural EEG recording. When patients had complete removal of all cortical areas with ictal and interictal epileptiform discharges, the clinical outcome was usually good. When areas with epileptiform discharges were left behind, good outcome was significantly less frequent. This correlation between complete resection and good outcome was independent of the presence or absence of CT-detected structural lesions or sharp waves on post-resection electrocorticography. These results support completeness of resection, defined by prolonged extraoperative EEG, as an important factor in seizure surgery.

Chloroquine neuromyotoxicity. Clinical and pathologic perspective.

Six cases of toxic myopathy and/or neuropathy with chloroquine and/or hydroxychloroquine therapy are described. Two patients had unique clinical and pathologic evidence of cardiomyopathy secondary to chloroquine or hydroxychloroquine therapy. One patient had polyneuropathy secondary to chloroquine toxicity. This may be the first documentation of several features of chloroquine/hydroxychloroquine toxicity: morphologic changes in human peripheral nerve in chloroquine toxicity; chloroquine/hydroxychloroquine cardiomyopathy diagnosed by endomyocardial biopsy; and hydroxychloroquine myotoxicity. Chloroquine is a neuromyotoxin that affects nerves and cardiac and skeletal muscles. Discontinuation of chloroquine and hydroxychloroquine resulted in marked improvement in most cases. The reversibility of the symptoms emphasizes the importance of recognizing potential signs of nerve, muscle, and cardiac toxicity in patients being treated with chloroquine or hydroxychloroquine.

Meningeal myofibroblastoma.

Myofibroblastoma is a recently described benign mesenchymal tumor. Only one case has been reported previously in the CNS. We report a second case of myofibroblastoma arising in the meninges in a 70-year-old woman who presented with visual changes. The histologic appearance was characterized by alternating areas of spindled and rounded cells separated by collagen and amianthoid fibers. Immunostaining demonstrated strong vimentin and focal smooth-muscle actin positivity; staining for epithelial membrane antigen, cytokeratin, S-100, desmin, myosin, glial fibrillary acidic protein, and factor VIII-related antigen was negative. Ultrastructurally, the myofibroblasts had features of both smooth-muscle cells and fibroblasts. Differentiating the benign myofibroblastoma from more aggressive meningeal sarcomas and meningeal meningiomas is important. The tumor most likely arises from myofibroblasts that probably reside in the meninges.

Divergent responses of human astrocytoma and non-neoplastic astrocytes to tumor necrosis factor alpha involve the 55 kDa tumor necrosis factor receptor.

The effects of tumor necrosis factor (TNF) on DNA synthesis, proliferation, and induction of gene/protein expression of TNF were compared in neoplastic and non-neoplastic adult human astrocytes. Previously, we demonstrated that TNF induced proliferative responses in non-neoplastic adult human astrocytes. In astrocytoma cells, however, TNF elicited both proliferative and cytostatic responses depending upon cell density and TNF concentration. This bimodal effect persisted even in a homogeneous, cloned astrocytoma cell line (STT-9C), and was inhibitable by neutralizing antibody to TNF. TNF treatment enhanced expression of TNF mRNA in astrocytoma cells but not in non-neoplastic astrocytes, and cell-associated or secreted TNF was detectable in any culture. The involvement of receptors in astrocyte responses to TNF was examined in serological studies using monoclonal antibodies Utr-1 to the 75 kDa, and Htr-9 to the 55 kDa TNF receptor. Antibody to the 55 kDa TNF receptor alone was able to mimic the effects of TNF in both neoplastic and non-neoplastic astrocyte cultures while antibody to the 75 kDa TNF receptor had no effect. These data indicate that the bimodal actions of TNF on human astrocytoma cells as well as the stimulatory effects on non-neoplastic adult astrocytes are regulated at least in part by the 55 kDa TNF receptor. Astrocyte TNF receptors, however, do not appear to constitute part of an autocrine growth pathway in either non-neoplastic or neoplastic human astrocytes.

Human astrocyte growth regulation: interleukin-4 sensitivity and receptor expression.

We previously reported that interleukin-4 (IL-4) inhibited proliferation of a human astrocytic cell line derived from non-neoplastic adult cortex. To determine whether this effect was receptor-associated and/or limited to only non-neoplastic astrocytes, we examined IL-4 responsiveness and receptor expression in human astrocytic cell lines derived from three different sources: non-neoplastic cerebral cortex (lines P1N, P2N, W3N); neoplastic low grade astrocytoma (LGA) (lines FRLGA, RTLGA); and highly malignant glioblastoma multiforme (GBM) (lines STTG1, CRTG2, WITG3, RUTG4). All lines except RUTG4 GBM expressed IL-4 receptor mRNA. Proliferation and DNA synthesis were markedly suppressed by IL-4 in a dose- and time-dependent manner in all non-neoplastic astrocyte and LGA lines, but not (0/4) GBM. This negative growth-regulatory effect of IL-4 was blocked by specific antibody to human IL-4 receptor but not by irrelevant IgG. In contrast, IL-4 stimulated interleukin-6 (IL-6) secretion in non-neoplastic astrocytes and LGA as well as in GBM cells expressing IL-4 receptor; secretion was undetectable in RUTG4 GBM which did not express receptor. These results indicate that: (i) responsiveness to IL-4 occurs in both non-neoplastic and neoplastic human astroglia; (ii) responsiveness is associated with IL-4 receptor expression; and (iii) sensitivity to negative growth signalling by IL-4 occurs selectively in astrocytes from non-neoplastic cortex or low grade neoplasia but not from highly malignant GBM.

Regulation of monocyte chemoattractant protein-1 expression in adult human non-neoplastic astrocytes is sensitive to tumor necrosis factor (TNF) or antibody to the 55-kDa TNF receptor.

Infiltration of the central nervous system (CNS) by monocytes is a characteristic of many non-malignant disease processes, although the signals regulating such traffic are unclear. Tumor necrosis factor (TNF) and other inflammatory cytokines have been shown to elicit production of monocyte chemoattractant activity in glioma cells, but the regulation of such activity in non-neoplastic adult astrocytes has not been examined. We previously observed that TNF constituted a proliferative signal for non-neoplastic adult human astrocytes in vitro involving the 55-kDa TNF receptor. In the present study, we demonstrate that TNF exposure enhances the expression of monocyte chemoattractant protein-1 (MCP-1) mRNA and functional monocyte chemoattractant activity in non-neoplastic astrocytes. Results indicated that MCP-1 mRNA expression was maximal within 3 h, and was further augmented by the protein synthesis inhibitor cycloheximide (CY). Antibody (htr-9) directed against the 55-kDa TNF receptor also elicited MCP-1 mRNA expression while antibody to the 75-kDa TNF receptor (utr-1) was ineffective. Secretion of monocyte chemoattractant activity was significantly greater in TNF- or htr-9-treated astrocytes than in utr-1-treated or untreated controls; activity was abolished by treatment with antibody to MCP-1. These findings suggest that non-neoplastic adult human astrocytes may contribute to CNS inflammatory responses by mediating recruitment of peripheral blood monocytes.

Human astrocytes proliferate in response to tumor necrosis factor alpha.

Two different human astrocytic cell lines derived from adult epilepsy surgical specimens were exposed in vitro to concentrations of 1-100 ng/ml recombinant tumor necrosis factor alpha (TNF alpha). Results indicated dose-dependent stimulation of DNA synthesis and proliferation. Both of these effects were abrogated by treatment with monoclonal antibody specific for TNF alpha but not by irrelevant murine IgG. Immunocytochemical characterization of TNF alpha-treated and control cultures indicated that greater than 98% of proliferating cells contained cytoplasmic glial fibrillary acidic protein (GFAP), and were therefore astrocytic in nature. These studies demonstrate that growth of adult human non-neoplastic astrocytes is stimulated by TNF alpha, an inflammatory cytokine produced primarily by macrophages but also by astrocytes.

Interferon-beta specifically inhibits interferon-gamma-induced class II major histocompatibility complex gene transcription in a human astrocytoma cell line.

We established cultures of human astrocytes and astrocytoma cells from surgical specimens, to study regulation of class II major histocompatibility (MHC) complex antigen expression by interferons. Using these cultures we previously showed that expression of the class II MHC determinant HLA-DR could be induced by interferon-gamma and this induction was inhibited by interferon-beta. In this report, we extend these observations by showing that the inhibitory effect of interferon-beta on interferon-gamma induction of the class II MHC gene HLA-DR alpha was exerted at the transcriptional level, as documented by nuclear run-on experiments and confirmed with blot hybridization analysis. Astrocyte expression of intercellular adhesion molecule-1 (ICAM-1) was induced efficiently by interferon-gamma, but not by interferon-beta, and induction of ICAM-1 expression by interferon-gamma could not be impaired by interferon-beta, suggesting that the suppressive effect on induction of HLA-DR was relatively gene-specific. Furthermore, interferon-beta did not antagonize interferon-gamma induction of HLA-DR expression in human monocytes, suggesting that the inhibition observed in astrocytes was relatively tissue-specific.

Cortical dysplasia: a histopathologic study of 52 cases of partial lobectomy in patients with epilepsy.

In utero migrational abnormalities account for most cases of cortical dysplasia. The histopathologic appearance of cortical dysplasia is often varied, making recognition and classification difficult. We studied 52 patients with cortical dysplasia who underwent partial lobectomy for medically intractable seizures in order to devise a simple histopathologic classification schema. The incidence of observed dysplasia in lobectomy specimens over an 11-year period (n = 360) was 14%. Patients ranged in age from 3 months to 47 years at the time of surgery (mean, 19 years; 29 male and 23 female patients). The temporal lobe was involved in 34 patients, frontal lobe in 18, parietal lobe in four, and occipital lobe in three. In three patients multiple lobes showed dysplasia. Dysplasia was right-sided in 29 patients and left-sided in 23 patients. Dysplasia was focal in 23 patients, multifocal in four patients, and diffuse in 25 patients. Three main histologic patterns of cortical dysplasia were observed: (1) a cortical laminar architectural disorganization and/or malalignment of neurons (26 patients), (2) clusters of atypical neurons and glia within the cortex (28 patients), and (3) a hypercellular molecular layer with increased numbers of neurons and glia (31 patients). In 23 patients more than one pattern of dysplasia was identified. Coexistent tumors were present in 13 patients, including ganglioglioma (eight patients), dysembryoplastic neuroepithelial tumor (three patients), and low-grade astrocytoma (two patients). Tuberous sclerosis was present in four patients. We conclude that most types of cortical dysplasia can be divided into three main histologic patterns, facilitating the recognition of dysplasia. In addition to the known association with tuberous sclerosis, tumors may coexist with cortical dysplasia.

Immunohistochemical characterization of the histiocytes in sinus histiocytosis with massive lymphadenopathy: analysis of an extranodal case.

We studied the morphologic, antigenic, and enzymatic characteristics of the histiocytes in an isolated extranodal case of sinus histiocytosis with massive lymphadenopathy (SHML) involving the CNS. To our knowledge, this represents the first immunohistochemically documented case of CNS SHML. The histiocytes exhibited the S-100(+), CD11c(+), alpha-1-antichymotrypsin(+) immunophenotype, which suggests that the histiocytes of SHML coexpress phenotypic characteristics of histiocytes of the mononuclear phagocytic system, and histiocytes of the interdigitating reticulum cell and Langerhan cell lineages. To examine the argument that the histiocytes in SHML may represent ordinary tissue macrophages of granulomatous inflammation, we compared the immunophenotypic characteristics of the histiocytes found in SHML to those found in xanthogranulomatous pyelonephritis (XP). We found that the histiocytes of XP have immunophenotypic characteristics of histiocytes belonging to the mononuclear phagocytic system lineage. The present study demonstrates that the histiocytes of SHML are distinct from the histiocytes of another xanthogranulomatous disorder, supporting the concept that SHML is a distinct clinicopathologic entity.

Anaplastic astrocytoma with granular cell differentiation: case report and review of the literature.

In contrast to the relatively common soft tissue form of granular cell tumor (GCT), intercerebral GCTs are rare neoplasms. The Schwann cell is the accepted cell of origin for soft tissue GCTs. However, the origin of intracerebral tumors is controversial. We report a case of a GCT intimately associated with an anaplastic astrocytoma. Immunohistochemical staining with glial fibrillary acidic protein demonstrated focal positive staining within the granular cells. Six GCTs from other body sites were stained with glial fibrillary acidic protein for comparison and all were negative. The granular cell component was diffusely positive for S-100 and negative for epithelial membrane antigen and cytokeratin. Ultrastructurally, filaments characteristic of astrocytic cells were demonstrated within some granular cells. Based on our light microscopic, electron microscopic, and immunohistochemical findings, the granular cell component of this anaplastic astrocytoma is likely astrocytic in origin. We propose that these tumors be designated astrocytic neoplasms with granular cell differentiation and their prognoses dictated by the grade of the glial component.

Protoplasmic astrocytoma. A clinicopathologic study of 16 tumors.

UNLABELLED: Protoplasmic astrocytomas, composed of process-poor astrocytic cells and a microcystic background, are rare variants of low grade astrocytoma. Three hundred eight low grade astrocytomas over a 23-year period were reviewed. Sixteen (5.2%) were classified as pure protoplasmic astrocytoma. Patients (12 males, 4 females) ranged in age from 2.5 to 41 years (mean, 20.7 years). All patients presented with seizures and three had headaches. Duration of symptoms ranged from 7 months to 28 years (mean, 6.6 years). Nine tumors (56%) were left-sided and seven right-sided (44%). Seven (44%) occurred in the temporal lobe, six (37%) in the frontal lobe, two (13%) in the parietal lobe, and one (6%) in the thalamus. Surgery consisted of partial lobectomy with total tumor resection in nine and biopsy alone in seven. Five patients received adjuvant therapy with no apparent effect on survival. At frozen section, protoplasmic astrocytoma was most confused with fibrillary low grade astrocytoma (n = 6). Follow-up revealed 10 patients with no evidence of disease 2 to 108 months postoperatively (mean, 41 months), 5 patients were alive with disease 10 to 84 months postoperatively (mean, 56 months) and 1 patient died with disease at 36 months. Of patients with total tumor resection, eight had no evidence of disease and one died with disease. IN CONCLUSION: (1) protoplasmic astrocytomas in this study were more frequently observed in males at a younger mean age than fibrillary low grade astrocytomas as reported in literature; (2) temporal and frontal lobes were the most likely site of origin; and (3) complete excision may be beneficial, whereas adjuvant therapy appeared to have no effect on outcome.

Dysembryoplastic neuroepithelial tumor.

Dysembryoplastic neuroepithelial tumor is a recently described but rare tumor that occurs in children and characterized by long-standing, intractable partial complex seizures. Due to a paucity of literature on this condition and its heterogeneous cellular composition, dysembryoplastic neuroepithelial tumors can present difficulties in diagnosis. The authors describe two cases of dysembryoplastic neuroepithelial tumor occurring in young patients (ages 8 and 19 years). Both tumors were located in the temporal lobe. Temporal lobectomy with excision of mesial structures resulted in resolution of the seizures. Differential diagnosis includes oligodendrogliomas, mixed gliomas, and gangliogliomas. Features of the dysembryoplastic neuroepithelial tumor that are useful in making the distinction include a multinodular and multicystic appearance, the presence of both neuronal and glial (oligodendrocytic and astrocytic) components with little if any cytologic atypia, the presence of accompanying cortical dysplasia, and the lack of an arcuate vascular pattern. Because dysembryoplastic neuroepithelial tumors are curable by excision, the recognition and correct diagnosis of this tumor is important.