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M B Delisle

Publications and source records attributed to M B Delisle.

At least 37 records · Page 2Linked to original sources
PubMed2000

So-called malignant and extra-ventricular neurocytomas: reality or wrong diagnosis? A critical review about two overdiagnosed cases.

Central neurocytoma (CN) is described as a rare intra-ventricular benign neuronal tumor of the brain. Two primary tumors first diagnosed as malignant and extra-ventricular neurocytomas are reported here. Histologically, the tumor of the first patient, a forty-one-year-old man, consisted of monotonous cells with round nuclei, but no fibrillar background. The second tumor, in a nineteen-year-old girl, showed areas of moderately pleomorphic round cells, with numerous rosettes and ganglion cell differentiation, in an abundant fibrillary network. Both presented calcifications. Mitoses were more frequent in recurrences and spinal locations than in the primaries. All tumors stained strongly for synaptophysin, and GFAP was partly positive in the first case only. Patients received post-surgical radiotherapy and were still alive eight and six years, respectively, after initial surgery. The interpretation of atypical cases, such as ours is not easy: the diagnoses finally retained were oligodendroglioma in the first case and ganglioneuroblastoma in the second case. Furthermore, neurocytomas atypical either by their unusual topographical or histological presentation or by their poor prognosis, have been frequently entitled in this way on synaptophysin positivity. So, we were prompted to reassess the entity of CN, seventeen years after the first description, to re-appreciate the reality of anatomo-clinical variants and to discuss the value of synaptophysin positivity in these tumors. In conclusion, it seems preferable to individualize true classical CN, which has a favorable outcome, from so-called extra-ventricular, atypical and anaplastic, clinically malignant neurocytomas for which complementary treatment is required.

Adolescent↗
PubMed2000

[Neurodegenerative disease associated with a mutation of codon 279 (N279K) in exon 10 of Tau protein].

Frontotemporal dementia and Parkinsonism linked to chromosome 17 (FTDP-17) are related to pathogenic mutations of the Tau gene. One of these, located at codon 279, results in an asparagine to lysine substitution. It was detected in three unrelated families from different origins. This mutation affects splicing, allowing exon 10 to be incorporated more frequently in the Tau transcripts, causing an abnormal preponderance of three-over four-repeat isoforms in soluble tau and the presence of the four-repeat isoforms in the insoluble tau. To better understand this newly described pathology, we analysed data from the three previously reported families. The American family, described as "pallido-ponto-nigral degeneration" is a large family which has been extensively studied (13 neuropathological studies). The Japanese family was initially presented as "pallidonigroluysian degeneration with iron deposition" and recently found to be related to N279 K mutation. We reported clinical, pathological and genetic data from the French family. Clinical particularities are ocular movements alterations with vertical supranuclear palsy, extrapyramidal signs (rigidity, dyskinesia, with atypical resting and postural tremor) and progressive dementia. Partial or no L-DOPA responsiveness is noted. These features led to discuss progressive supranuclear palsy, in some cases. There is no amyotrophy, nor any sensibility to neuroleptics, both signs being observed in other FTDP-17 syndromes. Neuropathology and immunohistochemistry confirm the presence of Tau immunolabeled inclusions, affecting mainly neurons in brain stem nuclei and glial cells in supratentorial white matter. Neuronal loss, which is moderate in frontal and temporal cortex, is severe in substantia nigra and globus pallidum. It is variable in other subcortical structures. In these structures, it is associated with iron deposition. This latter may participate in the degenerative process of cells and led to death in some specific neurons. The selectivity of neuronal death in hereditary diseases, when compared to data concerning sporadic neurodegenerative diseases which share similar clinical signs and neuropathological lesions, reinforces the hypothesis of an increased vulnerability of some neuronal populations which express specific sets of tau isoforms. Neurons particularly involved in these diseases express exclusively exon 10 + tau isoforms.

Exons↗
PubMed2000

[Lysosomal disorders. Diagnostic role of extra-cerebral biopsy].

Lysosomal disorders are related to dysfunctions of lysosomes which may affect enzymes, transporters or activators. Their clinical features are varied. This is due to several mechanisms, the metabolism of nervous tissue explaining its particular involvement in sphingolipidosis. The classifications are still changing and, recently, some ceroid-lipofuscinosis were included in this group. Biological diagnosis relies on biochemical study of accumulated substrate or on enzymatic assays. It remains sometimes difficult. The analysis of tissue is then a useful tool. Biopsies from extraneural tissues, essentially skin and conjunctival biopsies, are nowadays preferred to brain biopsies. However, the location of the biopsy varies according to the suspected disease. The specimen must be adequately prepared and electron microscopy is necessary. Results of this examination are summarized. The interest of the biopsy is not restricted to diagnosis, it is useful in follow-up of treated patients and for understanding the underlying pathophysiology.

Biopsy↗
PubMed1999

A mutation at codon 279 (N279K) in exon 10 of the Tau gene causes a tauopathy with dementia and supranuclear palsy.

Recently intronic and exonic mutations in the Tau gene have been found to be associated with familial neurodegenerative syndromes characterized not only by a predominantly frontotemporal dementia but also by the presence of neurological signs consistent with the dysfunction of multiple subcortical neuronal circuitries. Among families, the symptomatology appears to vary in quality and severity in relation to the specific Tau gene mutation and often may include parkinsonism, supranuclear palsies, and/or myoclonus, in addition to dementia. We carried out molecular genetic and neuropathological studies on two patients from a French family presenting, early in their fifth decade, a cognitive impairment and supranuclear palsy followed by an akinetic rigid syndrome and dementia. The proband died severely demented 7 years after the onset of the symptoms; currently, his brother is still alive although his disease is progressing. In both patients, we found a Tau gene mutation in exon 10 at codon 279, resulting in an asparagine to lysine substitution (N279K). Neuropathologically, widespread neuronal and glial tau accumulation in the cortex, basal ganglia, brain stem nuclei as well as in the white matter were the hallmark of the disease. These deposits were shown by immunohistochemistry and immunoelectron microscopy, using a battery of antibodies to phosphorylation-dependent and phosphorylation-independent epitopes present in multiple tau regions. In the neocortex, tau-immunopositive glial cells were more numerous than immunopositive neurons; the deeper cortical layers as well as the white matter adjacent to the cortex contained the largest amount of immunolabeled glial cells. In contrast, some brain stem nuclei contained more neurons with tau deposits than immunolabeled glial cells. The correlation of clinical, neuropathological and molecular genetic findings emphasize the phenotypic heterogeneity of diseases caused by Tau gene mutations. Furthermore, to test the effect of the N279K mutation and compare it with the effect of the P301L exon 10 mutation on alternative splicing of Tau exon 10, we used an exon amplification assay. Our results suggest that the N279K mutation affects splicing similar to the intronic mutations, allowing exon 10 to be incorporated more frequently in the Tau transcript.

Adult↗
PubMed1999

Characterization of choline compounds with in vitro 1H magnetic resonance spectroscopy for the discrimination of primary brain tumors.

RATIONALE AND OBJECTIVES: The authors sought to compare 1H magnetic resonance spectroscopy (MRS) spectra from extracts of low-grade and high-grade gliomas, especially with respect to the signals of choline-containing compounds. METHODS: Perchloric acid extracts of six high-grade and six low-grade gliomas were analyzed by 1H MRS at 9.4 Tesla. RESULTS: The signals of glycerophosphocholine (GPC) at 3.23 ppm, phosphocholine (PC) at 3.22 ppm, and choline (Cho) at 3.21 ppm were identified in both types of tumors. The absolute concentrations of all Cho-containing compounds (GPC + PC + Cho) in high-grade and low-grade gliomas were significantly different. The relative contributions of each of the Cho-containing compounds to the total choline signal were also statistically different. For high-grade gliomas, the choline signal is composed of GPC, PC, and Cho in a well-balanced contribution, whereas in low-grade gliomas, the signal is largely due to GPC with a small involvement of PC and Cho. CONCLUSIONS: The differences in the concentration and the repartition of Cho-containing compounds seem to be a marker of high-grade gliomas. They could also help to discriminate between high- and low-grade gliomas in some difficult cases, especially if there is histologic uncertainty between anaplastic astrocytomas and low-grade oligodendrogliomas.

Adult↗
PubMed1999

Neuronal apoptosis in Creutzfeldt-Jakob disease.

Neuronal loss is a salient feature of prion diseases; however, its causes and mechanisms are unclear The possibility that it could occur through an apoptotic process has been postulated and is consistent with the lack of inflammation in prion disorders as supported by experimental studies. In order to test this hypothesis in humans, we examined samples of frontal and temporal cerebral cortex, striatum, thalamus, and cerebellum from 16 patients who died from Creutzfeldt-Jakob disease. They included 5 sporadic cases, 5 familial, 3 iatrogenic, and 3 cases with the new variant. These were compared with age and sex matched controls. Using in situ end labelling, we identified apoptotic neurons in all the cases of Creutzfeldt-Jakob disease. A single labelled neuron was found in the eldest control. Apoptotic neurons were mostly found in damaged regions and their presence and abundance seemed to correlate closely with neuronal loss. This supports the view that apoptosis of neurons is a feature of prion diseases and may contribute to the neuronal loss which is one of the main characteristics of these conditions. Neuronal apoptosis also correlated well with microglial activation, as demonstrated by the expression of major histocompatibility complex class II antigens, and axonal damage, as identified by beta-amyloid protein precursor immunostaining. In contrast, we found no obvious relationship between the topography and severity of neuronal apoptosis and the type, topography, and abundance of prion protein deposits as demonstrated by immunocytochemistry.

Adult↗
PubMed1999

[Central neurocytoma. Immunohistochemical study: MIB1, p53 and bcl-2. Report of 5 cases].

To further characterize central neurocytoma, a rare intraventricular tumour described in 1982, we analyzed six tumours by immunohistochemistry for MIB1, p53 and bcl-2. bcl-2, an inhibitor of p53-mediated apoptosis is frequently expressed in gliomas, especially in tumors with wild-type p53. Its expression in peripheral neuroblastomas suggests a down-regulation during final terminal differentiation. Six tumors from five patients (one female/four males, age ranged from 18 to 63 years) were examined. All patients were alive from 2 to 88 months after initial surgical resection. On histological sections, tumours demonstrated a typical pattern. Synaptophysin staining was seen in all cases. Proliferation index was low (< 4.5%). bcl-2 was never expressed. p53 expression varied but within low values (< 10% of cells). These latter antibodies were rarely analyzed until now in this usually benign neoplasm which represents a well differentiated variant of neuron derived tumors.

Adolescent↗
PubMed1999

[Neuronal apoptosis in human prion diseases].

Neuronal loss is a salient feature of prion diseases; however, its causes and mechanisms are unclear. The possibility that it could occur through an apoptotic process has been postulated and this is consistent with the lack of inflammation in prion disorders as supported by experimental studies. In order to test this hypothesis in humans, we examined samples of frontal and temporal cerebral cortex, striatum, thalamus and cerebellum from 26 patients who died from prion diseases. They included 16 cases of Creutzfeldt-Jakob disease (5 sporadic cases, 5 familial, 3 iatrogenic, and 3 cases with the new variant), and 10 cases of fatal familial insomnia including 8 homozygotes methionine/methionone at codon 129 of the prion protein gene and 2 heterozygotes. These were compared with age and sex matched controls. Using in situ end labelling, we identified apoptotic neurons in all the cases of Creutzfeldt-Jakob disease. A single labelled neuron was found in the eldest control. Apoptotic neurons were mostly found in damaged regions and their presence and abundance seemed to correlate closely with neuronal loss. This supports the view that apoptosis of neurons is a feature of prion diseases and may contribute to the neuronal loss which is one of the main characteristics of these conditions. Neuronal apoptosis also correlated well with microglial activation as demonstrated by the expression of major histocompatibility complex class II antigens and axonal damage as identified by beta-amyloid protein precursor immunostaining. In contrast, we found no obvious relationship between the topography and severity of neuronal apoptosis and the type, topography and abundance of prion protein deposits as demonstrated by immunohistochemistry.

Adult↗
PubMed1999

[Does allergic fungal sinusitis exist? Preliminary results of a prospective study].

Allergic aspergillar sinusitis is a very controversial clinical feature. We present results of a prospective study aimed at evaluating the reality of allergic aspergillar sinusitis in a nosologic and clinical point of vue. During a 5 months period, 31 patients underwent surgery: 21 sino-nasal polyposis, 5 chronic sinusitis without polyposis, 5 chronic sinusitis with radiologic images evocative of mycosis. The study was carried out using clinical criteria (per-operative discovery of glue-like, thickened and viscous aspect of the secretions), pathologic criteria (the presence of elements consitutive of allergic mucin), mycological criteria (direct examination and culture), and immunoallergic criteria (specific IgE for Aspergillus fumigatus, serology for Aspergillus fumigatus and Aspergillus flavus (IgM, IgG), skin tests for Aspergillus fumigatus). In three cases we suspect an allergic aspergillar sinusitis (one patient presenting a bilateral chronic sinusitis and two patients presenting a sinonasal polyposis). In two patients presenting a sinonasal polyposis, a allergic fungal sinusitis was suspected, fungal identification was not possible.

Adult↗
PubMed1999

Cavernous hemangiomas of the orbit: MR imaging.

PURPOSE: To describe the MR imaging findings in eight patients with cavernous hemangioma of the orbit. METHODS: CT, MR imaging and echographic studies of eight patients with cavernous hemangioma localized in the orbit were reviewed. All patients presented with a progressive symptomatology: in seven cases with a painless proptosis, in one case with a failing of visual acuity of the concerned eye. The patients were examined with T2- and T1-weighted spin echo sequences, before and after intravenous administration of Gadolinium*, in axial, coronal and sagittal planes. In seven patients, a fat saturation prepulse was given after the Gd-enhanced study. Two patients were also examined with CT scan, with and without intravenous contrast administration. Three patients underwent a Doppler color-coded transorbital sonography. The analyzed criteria were: location, form, margins, size, signal or density. Seven patients underwent surgery with pathologically proved cavernous hemangioma. In one patient, therapy was conservative, because of the absence of significant clinical complaints. RESULTS: In all cases, MRI showed a well-defined intraconal mass. The lesions were homogeneous, isointense to muscle on the T1-weighted sequence and hyperintense to muscle on the T2-weighted sequences. In five cases, a peripheral rim, hypointense to the mass on the T1- and T2-weighted sequences could be observed. After Gadolinium*, six lesions showed initial central patchy enhancement. On the three following T1-Gadolinium* sequences, these lesions showed total and homogeneous filling. In two patients, the lesions showed immediate homogeneous enhancement. On CT, the orbital masses were spontaneously hyperdense, with associated focus of microcalcifications. On echography, the lesions appeared hyperechogenic, heterogeneous, with individualization of small areas of very slow flow. CONCLUSION: From the analysis of the MR appearance of an intraconal, well-defined mass, associating homogeneous signal, isointense to muscle on T1-weighted sequence, hyperintense on T2-weighted sequence, and especially progressive filling on Gd-enhanced sequences, the diagnosis of cavernous hemangioma may be highly suggestive, in a patient presenting a painless progressive proptosis.

Adult↗
PubMed1999

[Fatal familial insomnia].

Since its description in 1986, Fatal Familial Insomnia (FFI) became the third most common inherited prion diseases (23 described families, 3 isolated cases). It is characterized by a mutation at codon 178 of the prion protein gene cosegregating with the methionine polymorphism at codon 129 of the mutated allele. Insomnia, dysautonomia, disruption of circadian rhythms and motor dysfunctions (myoclonus, ataxia, dysarthria, spasticity) are the main clinical symptoms in the homozygote patients (met/met at codon 129). Heterozygotes have motor dysfunctions from onset and cognitive changes. Pheno-typic variability does not appear to be strictly related to codon 129 polymorphism as recently stressed in some reports. Neuropathology shows marked neuronal loss and gliosis in the thalamus, especially in the medio-dorsal and antero-ventral nuclei, without any amyloïd deposits. Some spongiosis may be seen essentially in the cerebral cortex, in patients with longer duration disease. The D178N mutation coupled with the 129 valine codon is linked to a subtype of Creutzfeldt-Jakob disease. However, in these two phenotypically different diseases, two protease resistant fragments of the pathogenic PrP (PrPres) are accumulated. They differ in molecular mass. In FFI PrPres, the unglycosylated form is underrepresented. This particularity does not result from the preferential conversion of the glycosylated forms but from an inaccessibility of non glycosylated form to conversion. PrPres has been shown to be form allelic origin. Neuronal apoptosis was found to contribute to neuronal loss in FFI. Its presence correlates with neuronal loss, being invariably noticed in the thalamus and medullary nuclei. It is not correlated with PrPres accumulation. The quantity of deposits is globally low in FFI brains and rarely immunohistochemically detected. Pathogenesis of lesions and clinical signs remain to be assessed. Protein dysfunction could be hypothesized according to some clinical and experimental data as well as to the discordance between protein accumulation and programmed cell death. Neurotoxicity is also postulated. Studies on this pathology led to consider the existence of "strains" in human prion diseases. Despite remarkable advances, many issues remain unsolved in this non spongiform prion disease.

Amino Acid Substitution↗
PubMed1998

Clear-cell meningioma of the cauda equina.

Meningiomas are rare tumours in children and lumbar lesions are exceptional. We report a clear-cell meningioma (CCM) of the cauda equina in a 10-year-old girl. The tumour was diagnosed by MRI, showing an enhancing intradural mass extending from L1 to L4. Pathology and immunohistochemical study demonstrated a CCM. The patient had a recurrence 6 months after the operation requiring further surgery. CCM are rare lesions, characterised by abundant cytoplasmic glycogen particles. Complete surgical removal is necessary because, despite their benign histological appearance, CCM are potentially aggressive and may recur, spread locally and even metastasize.

Back Pain↗
PubMed1998

Recurrent intracranial neurenteric cysts.

Neurenteric cysts are cystic lesions lined by a columnar epithelium of endodermal derivation. They are rarely located in the central nervous system. We describe the case history of two recurrent neurenteric cysts located within the posterior fossa: one in the 4th ventricle and the second in the cerebellopontine angle. The literature is reviewed and the follow-up and recurrence of such cysts are discussed.

Adult↗
PubMed1998

The cell cycle gene SKP1 is regulated by light in postnatal rat brain.

During the early postnatal phase of high neuronal plasticity, an altered visual input leads to great modifications of visual cortex organization [Y. Frégnac, M. Imbert, Development of neuronal selectivity in primary visual cortex of cat, Physiol. Rev., 64 (1984) 375-434; D.H. Hubel, T.N. Wiesel, S. LeVay, Plasticity of ocular dominance columns in monkey striate cortex, Philos. Trans. R. Soc. London, Ser. B, 278 (1977) 377-409.]. We used refined differential screening of an organized cDNA library to identify the genes that may participate in this plasticity. We isolated a candidate plasticity gene encoding for a 163 aa protein that is closely related to the human and yeast Skp1p, a key factor in cell cycle progression [C. Baï, K. Hofman, L. Ma, M. Goebl, J.W. Harper, S.J. Elledge, SKP1 connects cell cycle regulators to the ubiquitin proteolysis machinery through a novel motif, the F-box, Cell, 86 (1996) 263-274; C. Connelly, P. Hieter, Budding yeast SKP1 encodes an evolutionary conserved kinetochore protein required for cell cycle progression, Cell, 86 (1996) 275-285; H. Zhang, R. Kobayashi, K. Galaktionov, D. Beach, p19Skp1 and p45Skp2 are essential elements of the cyclin A-CDK2 S phase kinase, Cell, 82 (1995) 915-925.]. Northern blot analysis showed that the expression of SKP1 (Skp1p gene) dramatically decreased after 2 h of light stimulation in the visual cortex of young dark-reared rats. This down regulation lasted at least 72 h. It was specific for the critical period as we did not observe any significant regulation of SKP1 mRNA by light in adult dark-reared rat brain. The down regulation was observed in the superior colliculus but also in the frontal cortex and in the hippocampus. The fact that this down regulation was not restricted to the visual system, suggested that it could be produced by dark rearing-induced hormonal changes. The significance of SKP1 expression in the brain and its regulation are discussed.

Animals↗
PubMed1998

[Clear cell meningioma: recurrent intraspinal tumor in a child].

BACKGROUND: Meningiomas represent 1.5% to 4.3% of cerebral and medullar primary tumors in children. CASE REPORT: A 9-year-old girl had a history of thoracolumbar scoliosis. An intracanalar and extramedullar tumor was confined to the lumbar region. Resection identified a clear cell meningioma. A symptomatic and tumoral recurrence occurred 5 months later in the same region. After a second resection, the patient received radiotherapy. At 8 months follow-up, no recurrence was documented. CONCLUSIONS: A stiff and painful scoliosis can be predictive of expansive intracanalar tumor. The recurrent or multifocal evolution of clear cell meningioma show the "aggressive behavior" of this histological type. A preventive radiotherapy could be proposed, depending on the age of the patient and the localization of the tumor.

Child↗