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M L Estes

Publications and source records attributed to M L Estes.

At least 55 records · Page 3Linked to original sources
PubMed1992

Ocular findings associated with neurofibromatosis type II.

BACKGROUND: Neurofibromatosis has been recently acknowledged as consisting of a number of different diseases. Neurofibromatosis (NF) type I and NF type II are the most clearly defined. Type II is characterized by bilateral acoustic neuromas and is rare (its incidence is 1/50,000). The previously reported ocular associations of NF type II are posterior subcapsular cataracts, Lisch nodules, and combined hamartomata of the retinal pigment epithelium and retina. In this study, the authors attempt to define further the ocular manifestations of NF type II. METHODS: The authors prospectively examined 9 patients who met the diagnostic criteria for NF type II (age, 18 to 38 years; mean, 25 years). RESULTS: Seven of nine patients had epiretinal membranes in the posterior pole. None of these epiretinal membranes were visually significant. In addition, five patients had central posterior cortical cataracts and five had peripheral wedge-shaped cortical cataracts. CONCLUSION: The presence of epiretinal membranes in young patients may represent another clinical finding associated with NF type II. Epiretinal membranes, central posterior cataracts, peripheral cortical cataracts, or combined hamartoma of the retinal epithelium and retina in young patients should alert the ophthalmologist to include NF type II in the differential diagnosis in patients with stigmata of NF type II.

Adolescent↗
PubMed1992

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.

Adult↗
PubMed1992

Magnetic resonance imaging of adult intra-axial brain tumors.

The detection and characterization of intra-axial tumors in the adult have been greatly improved with the advent of magnetic resonance (MR) imaging, particularly when combined with paramagnetic contrast enhancement. MR imaging allows tumor localization along with evaluation of edema, tumor margins, intrinsic signal intensity on T1- and T2-weighted sequences, and the presence or absence of enhancement. Consideration of these characteristics together with pertinent clinical history forms the basis of a reasonable differential diagnosis. The article summarizes the MR imaging characteristics and pathologic findings of the major intra-axial tumors of adults with emphasis on differential considerations.

Adult↗
PubMed1991

Alternating sequential intracarotid BCNU and cisplatin in recurrent malignant glioma.

The authors entered 43 patients with recurrent malignant glioma in a trial of alternating sequential intracarotid BCNU and cisplatin. Protocol design was alternating courses of BCNU (2 doses, 300 to 400 mg each) and cisplatin (2 doses, 150 to 200 mg each) each at 4-week to 6-week intervals. Eight of 40 patients (20%) evaluable after the first course of BCNU showed partial or minor response. Only 18 patients were evaluable after the first course of cisplatin, and 5 were evaluable after the second course of BCNU. Median survival was 9 months (range, 2 weeks to 6 years). Cerebral or ocular toxicity unique to this method of chemotherapy administration and failure to show clinical improvement were the most common reasons for removal from study. Because of the high attrition rate, the authors were unable to determine a meaningful response to alternating sequential BCNU and cisplatin or to test the clinical degree of cross-resistance to these agents in human malignant glioma.

Adult↗
PubMed1991

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.

Adult↗
PubMed1991

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.

Adolescent↗
PubMed1991

Sudden death and paroxysmal autonomic dysfunction in stiff-man syndrome.

Two women with typical stiff-man syndrome (SMS) developed increasingly frequent attacks of muscle spasms with severe paroxysmal autonomic dysfunctions such as transient hyperpyrexia, diaphoresis, tachypnea, tachycardia, pupillary dilation, and arterial hypertension. Autoantibodies to GABA-ergic neurons were identified in the serum of both patients and in the cerebrospinal fluid of one. Both died suddenly and unexpectedly. General autopsy did not reveal the cause of death. Neuropathological studies revealed perivascular gliosis in the spinal cord and brain stem of one patient and lymphocytic perivascular infiltration in the spinal cord, brain stem, and basal ganglia of the other. The occurrence of a chronic inflammatory reaction in one of the two patients supports the idea that an autoimmune disease against GABA-ergic neurons may be involved in SMS. A review of the literature indicates that functional impairment in SMS is severe and prognosis is unpredictable because of the potential for sudden and unexpected death. Both muscular abnormalities and autonomic dysfunctions may result from autoimmunity directed against GABA-ergic neurons.

Adult↗
PubMed1991

Monocyte tumoricidal activity and tumor necrosis factor production in patients with malignant brain tumors.

Monocyte-mediated tumoricidal activity, tumor necrosis factor alpha (TNF alpha) secretion and gene expression were examined in astrocytoma patients, patients with other types of brain tumors (primary or metastatic), and normal individuals. The spontaneous monocyte-mediated tumoricidal activity of either patient group against an astrocytoma cell line was significantly greater than normal. There was no difference between patient groups. When monocytes were stimulated with lipopolysaccharide in vitro, tumoricidal activity increased in all patient groups. Patient monocyte activity tested shortly (48 h) after surgery was not different from that before surgery. Both spontaneous and stimulated monocyte cytocidal activities were tumor-cell-restricted: melanoma and astrocytoma cells were equally susceptible but non-neoplastic glial cells were not affected. Examination of monocyte TNF alpha secretion and mRNA expression indicated that patient activity was comparable to or greater than normal. These results demonstrate that, despite steroid therapy, circulating monocytes in astrocytoma and other brain tumor patients retain intact functional activity.

Adult↗
PubMed1991

Early brain metastases in endometrial carcinoma.

Endometrial carcinoma is the most common invasive neoplasm of the female genital tract. Yet, intracranial metastases are rare and usually associated with widespread disease. We report three patients with endometrial carcinoma and early brain metastases, two with unsuspected endometrial carcinoma presenting with neurologic symptoms and one who developed neurologic symptoms on the day of hysterectomy. Histologically, one tumor was a clear cell carcinoma and two were endometrial adenocarcinoma. In tumors with a mixture of nuclear grades, the most undifferentiated portion metastasized. Two tumors displayed vascular invasion and deep myometrial invasion. Only one had positive estrogen receptors. Intracranial metastases can occur early in the course of endometrial carcinoma. They are associated with aggressive high-grade neoplasms with deep myometrial and vascular invasion.

Adenocarcinoma, Papillary↗
PubMed1991

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.

Astrocytes↗
PubMed1990

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.

Adult↗
PubMed1990

Characterization of adult human astrocytes derived from explant culture.

Four different human astrocytic cell lines established from either epilepsy surgical specimens or cerebral white matter obtained during thalamotomy for tremor in a patient with multiple sclerosis were characterized using morphologic analysis, ultrastructural attributes, growth characteristics, and immunocytochemical analysis. Immunocytochemical characterization of cultures indicated a mean of 84% of cells contained cytoplasmic glial fibrillary acidic protein (GFAP): to confirm that GFAP(+) cells also proliferated, bromo-deoxyuridine (BrdU) uptake was measured in cell line. Our method of simplified explant culture allows establishment of astrocytic cell lines from a variety of pathologic substrates using limited amounts of human material.

Adult↗
PubMed1990

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.

Astrocytes↗
PubMed1990

The cytoarchitectural organization of the human parabrachial nuclear complex.

The cytoarchitecture of the parabrachial nuclear complex in adult and infant human brain was studied. Lying in the dorsolateral pontine tegmentum, surrounding the superior cerebellar peduncle, this complex in several mammalian species is interconnected with autonomic centers in the medulla oblongata, hypothalamus, thalamus, amygdala, and cortex. Postmortem human brain tissue was stained for Nissl substance and fiber tracts with a modified Klüver-Barrera stain. Examination of the tissue revealed distinct medial and lateral subdivisions, similar to descriptions in other mammals. The organization of the parabrachial complex was more obvious in the infant tissue than the adult, because of less myelination of the large fibers of the adjacent superior cerebellar peduncle and lateral lemniscus. Within the lateral parabrachial nucleus, 7 distinct subgroups of cells were identified on the basis of their location and staining characteristics. These were named according to their location in the parabrachial complex and were the central, superior, interstitial, dorsal, dorsolateral, lateral, and ventrolateral. Two subnuclei were found within the medial parabrachial nucleus, the dorsomedial and ventromedial. Additionally, neurons within the superior cerebellar peduncle were arranged in cellular bridges running between the lateral and medial subdivisions. These data suggest that the parabrachial complex in the human brain is organized cytoarchitecturally, similar to other mammals, however, this organization is obscured with increasing myelination in adulthood.

Adult↗
PubMed1990

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.

Adult↗
PubMed1989

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.

Adult↗
PubMed1989

The canine nucleus tractus solitarii: light microscopic analysis of subnuclear divisions.

The nucleus tractus solitarii (nTS) is a complex structure situated in the dorsal medulla oblongata. This region receives primary visceral and gustatory sensory afferent fibers and has widespread interconnections with brainstem structures, hypothalamus, and limbic forebrain. In both rat and cat distinct subnuclei correlate with specific functions of the nTS. Since the canine model is used extensively for physiological study and evidence from this laboratory supports a critical role for the canine nTS in cardiovascular function, we examined its morphological organization. Light microscopic analysis of cellular and fiber patterns of the nTS revealed nine discrete regions based on cytoarchitecture: the commissural, lateral, ventral, dorsal, intermediate, interstitial and medial subnuclei, the subnucleus gelatinosa, and the dorsal parasolitary region. Analysis of each subnucleus revealed that both the lateral and ventral subnuclei contained two distinct neuronal groups based on cell size. Neurochemical and functional correlates are being provided by ongoing analyses of each subnucleus of the nTS.

Animals↗