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J Mikol

Publications and source records attributed to J Mikol.

At least 37 records · Page 2Linked to original sources
PubMed1999

Neuropathology of prion diseases.

Prion diseases include sporadic forms such as Creutzfeldt-Jakob disease (CJD), familial forms (familial CJD), fatal familial insomnia, Gerstmann-Sträussler-Scheinker disease, and acquired forms (i.e., kuru, iatrogenic CJD). The most frequent of the latter include acquired forms secondary to injections of human cadaveric pituitary-derived growth hormone and the new variant of CJD--probably related to bovine spongiform encephalopathy. The communal lesions are neuronal loss, spongiosis and gliosis and, inconstantly, the presence of amyloid plaques and different kinds of small deposits immunolabeled with anti-prion (PrP) antibodies. Their number and topography are variable. Recent works have shown the role of the host genotype, especially of codon 129, in the susceptibility to these diseases. We have tried to correlate neuropathology with the genotype of codon 129 and the type of PrP to establish a molecular classification.

Animals↗
PubMed1999

Spinal melanotic schwannoma: a tumour with poor prognosis.

AIM: To clarify the prognosis of melanotic schwannoma. This is a rare tumour which is generally considered as a benign lesion, reported in many cases with a short follow-up only. METHODS AND RESULTS: Five cases of spinal melanotic schwannoma were retrospectively studied. The tumours were examined using standard histological, immunohistochemical and ultrastructural methods. No features of malignancy (high mitotic count, atypia or necrosis) were found in the primary tumours. The follow-up period ranged from 3 to 7 years. Malignant clinical behaviour was clear-cut in four cases: three patients died from metastases to various sites and one presented several discrete spinal tumours of the same type seven years after the first operation. Only one patient presented no recurrence and was free of disease 6 years after initial diagnosis. The review of 57 cases of the literature (including our cases), showed that 15% of the cases had recurrences and 26.3% were complicated by metastasis. Only 53% of the cases followed for more than 5 years, were free of disease vs. 67.5% of the cases with shorter follow-up. Twenty additional cases had no follow-up. CONCLUSION: Appropriate long-term follow-up is required for all melanotic schwannomas, as it may recur or metastasize after more than 5 years, even in the absence of overt malignant histological features.

Adult↗
PubMed1999

[Acquired forms of Creutzfeldt-Jakob disease].

AIM: To establish the recent neuropathological data concerning the acquired forms of human prions diseases at the exception of the new variant. RESULTS: Kuru transmitted by cannibalism involved mainly the cerebellum with cerebellar tracts degeneration and presence of amyloid plaques called "kuru plaques" labeled by anti PrP antibodies. To day the disease has disappeared. Iatrogenic forms have been found after corneal graft or more frequently dura-mater graft. In these later cases, neuronal loss, spongiosis and gliosis are diffuse in cerebral and cerebellar cortex with the same intensity. The cases associated with pituitary-derived human growth hormone administration are observed in young patients. Histologic lesions, in 16 cases, are present in basal ganglia, thalamus, brain stem and predominantly in the cerebellum especially in the granule cell layer. Cortical involvement is moderate. Plaques have not been always looked for. CONCLUSION: The diversity of acquired forms is in favor of the hypothesis of selection of specific strains.

Brain↗
PubMed1999

Cerebral amyloid angiopathy (CAA) with presentation as a brain inflammatory pseudo-tumour.

Cerebral amyloid angiopathy (CAA) is frequent but often asymptomatic. It can induce lobar haemorrhage, rapidly progressive dementia or recurrent transient neurological symptoms, other presentations being less frequent. We report 3 patients in their sixties presenting with a space occupying lesion which was the first manifestation of CAA. They were operated with a diagnosis of cerebral tumour. In all three cases, macroscopy was similar, the lesions were superficial in the cerebral cortex and the preoperative diagnoses were glioblastoma, meningioma and cavernoma. Histologically, the lesions consisted of a large inflammatory granuloma with numerous lipophages and siderophages surrounding capillaries with prominent endothelial cells. Vessels in the near cortex and meninges and within the granuloma harboured heavy amyloid deposits immunolabelled by anti-P component, anti-protein beta A4 with a A40 predominance and anti-apolipoprotein E. Adjacent cerebral cortex showed reactive gliosis and rare senile plaques. Amyloidosis is rarely considered among diagnoses of space occupying lesions. In our three cases, CT scan and MRI changes were related to the presence of an inflammatory granuloma around foci of haemorrhage and amyloid laden vessels.

Aged↗
PubMed1998

The GnRH receptor gene is preferentially expressed in functioning gonadotroph adenomas and displays a Mae III polymorphism site.

OBJECTIVE: Given the central role of the GnRH receptor (GnRHR) in the regulation of the gonadotrophin secretion, it might be implicated directly or indirectly in the pathogenesis of gonadotroph tumours. DESIGN: We determined if GnRHR mRNA was expressed in gonadotroph tumours using RT-PCR and analysed the GnRHR gene for the presence of mutations in its coding region, using direct sequencing of PCR products. Results were analysed according to the pattern of expression of alpha, beta-FSH and beta-LH subunit (SU) genes. SUBJECTS: RNA was extracted from 20 gonadotroph tumours identified by immunohistochemistry (> 10% of stained cells): 9 adenomas were functioning (high serum gonadotrophin levels), 3 were associated with high alpha-SU levels and 8 were nonfunctioning. Genomic DNA was extracted from 64 normal subjects. RESULTS: We found GnRHR mRNA in 12 tumours (60%): 8/9 functioning (88%), 1/3 alpha-secreting (33%) and 3/8 nonfunctioning (37.5%) gonadotroph adenomas. There was a significant association between GnRHR expression and immunostaining for beta-FSH (P = 0.014). The nucleotide sequence of the amplified products was identical to that of human pituitary except for the presence, in 3 functioning adenomas, of a silent C to T transition at nucleotide 453 encoding for the serine residue situated in the second intracellular loop at position 151. Heterozygosity provided evidence that both alleles were transcribed in these tumours. This substitution creates a Mae III restriction site. Genomic DNA from normal subjects were then tested for the presence of this new polymorphism. The frequency of the heterozygosity (18.7%) was not significantly different from that found in gonadotroph tumours (25%) and this new Mae III polymorphism site cannot be used as a tumoural marker. CONCLUSION: The GnRHR gene is preferentially expressed in functioning rather than in nonfunctioning gonadotroph adenomas, but no mutations altering the coding region of the gene were found to further substantiate its role in the pathogenesis of gonadotroph tumours.

Adenoma↗
PubMed1997

Peripheral neuropathy in human immunodeficiency virus-infected patients with the diffuse infiltrative lymphocytosis syndrome.

A subset of human immunodeficiency virus (HIV)-infected patients develop persistent CD8 hyperlymphocytosis and a Sjogren's syndrome-like syndrome associated with multivisceral CD8 T-cell infiltration, known as the diffuse infiltrative lymphocytosis syndrome (DILS). Patients with DILS tend to have higher CD4 cell counts, fewer opportunistic infections, and longer survival times than other HIV-infected patients. Peripheral nerve involvement in DILS has been poorly documented. We studied 12 HIV-infected patients with CD8 hyperlymphocytosis, DILS, and clinical signs of peripheral neuropathy. Two of 4 patients who were HLA typed were HLA-DR5 and 1 was HLA-DR6. All patients had the sicca syndrome and multivisceral involvement. The neuropathy was acute or subacute, always painful, and symmetrical in 8 cases. Electrophysiology was consistent with axonal neuropathy in 10 of 12 patients. Nerve biopsy showed marked angiocentric CD8 infiltrates without mural necrosis (12 of 12), and abundant expression of HIV p24 protein in macrophages (12 of 12). The HIV genome was detected by polymerase chain reaction in nerve homogenates. Zidovudine therapy was associated with improvement in 6 of 6 patients and steroid therapy was beneficial in 4 of 5 patients. No T-cell lymphoma was observed during follow-up, but 2 patients developed a primary B-cell lymphoma. We conclude that DILS neuropathy represents HIV-associated neuropathy, characterized by marked CD8 infiltration and abundant HIV in nerve, that improves with zidovudine or steroid therapy, and probably reflects a systemic host-determined and antigen-driven response to HIV.

Acquired Immunodeficiency Syndrome↗
PubMed1997

[Neuromeningeal sites of multiple myeloma: 3 cases and review of the literature].

Neurologic manifestations are not unusual in multiple myeloma. Conversely meningeal and cerebral involvement have been very rarely reported. We report here on three patients with multiple myeloma and meningeal or cerebral involvement (two of them with autopsy study): one case of cerebellar involvement associated with secondary plasma cell leukemia and two cases of meningeal involvement. We reviewed the characteristics of 20 cases of meningeal involvement with demonstration of plasma cells at cerebrospinal fluid analysis (18 previously reported cases and our two patients). Meningeal involvement occurs in patients with initially stage III multiple myeloma in 85% of cases and is associated with the occurrence of plasma cell leukemia in 20% of cases. The most frequent neurologic signs are: confusion (60%), altered consciousness (25%), gait disorder (25%), cranial nerve palsy (25%). Meningismus is rarely present. Diagnosis is based on cerebrospinal fluid analysis after lumbar puncture which should be made after cranial magnetic resonance imaging. The diagnosis of intra-cranial haemorrhage and infectious meningitis have to be cautiously ruled out. Despite treatments (systemic and/or intrathecal chemotherapy, radiation therapy), prognosis is very poor: mean time of survival after the occurrence of neurologic signs is about 2 months.

Aged↗
PubMed1997

Allelic origin of the abnormal prion protein isoform in familial prion diseases.

The hallmark of prion diseases is the presence of an aberrant isoform of the prion protein (PrP(res)) that is insoluble in nondenaturing detergents and resistant to proteases. We investigated the allelic origin of PrP(res) in brains of subjects heterozygous for the D178N mutation linked to fatal familial insomnia (FFI) and a subtype of Creutzfeldt-Jakob disease (CJD178), as well as for insertional mutations associated with another CJD subtype. We found that in FFI and CJD178 subjects, only mutant PrP was detergent-insoluble and protease-resistant. Therefore, PrP(res) derives exclusively from the mutant allele carrying the D178N mutation. In contrast, in the CJD subtype harboring insertional mutations, wild-type PrP was also detergent-insoluble and likely to be protease-resistant. Our findings indicate that the participation of the wild-type PrP in the formation of PrP(res) depends on the type of mutations, providing an insight into the molecular mechanisms underlying the phenotypic heterogeneity in familial prion diseases.

Alleles↗
PubMed1997

Recurrent optic neuromyelitis with endocrinopathies: a new syndrome.

We report a new syndrome that we call "recurrent optic neuromyelitis with endocrinopathies" in eight Antillean women from Martinique and Guadeloupe Ocular involvement was either monocular or binocular, whereas myelopathy was acute or subacute. In seven patients, myelopathic symptoms recurred, and in six patients, visual problems recurred. Spinal cord involvement was a consistent band-like pseudo-syringomyelic dissociated sensory loss. All eight patients had endocrinopathies consisting of amenorrhea, galactorrhea, diabetes insipidus, hypothyroidism, or hyperphagia. Spinal cord MRI revealed cavitation-like images. Various immunosuppressant treatments had little effect on the uniformly deteriorating course, ending in blindness and paraplegia. Six patients died within 5 years of onset, and an autopsy in one patient showed multiple demyelinizing lesions of the spinal cord with thickened blood vessels walls without evidence of inflammation. These cases appear to constitute a syndrome distinct from MS and from classic Devic's syndrome, not only because of the association with endocrinopathies but because of the stereotypy of the recurrences, the absence of MRI lesions in the cerebral white matter, and the unusual image of cavitation of the spinal cord. The syndrome is also distinct from HTLV-I-associated paraparesis, which is endemic in the West Indies.

Adolescent↗
PubMed1997

[Nervous system lymphoma in HIV infection].

Primary CNS lymphoma is recognized as one of the criteria of AIDS. The incidence is 0.4 to 0.56% of AIDS complications. Non-Hodgkin's lymphomas appear as multicentric tumours, mostly located in the hemispheres; they have a B phenotype and have a high grade of malignancy. They are sometimes associated with opportunistic infections. Survival is around 4 to 5 months. The presence of EBV in these tumours is an argument to propose a synergistic role of this virus in the pathogenesis of these tumours. Secondary lymphomas are observed in 40 to 47% of these tumours and must be systematically looked for. Hodgkin's disease is rare. It is mostly diagnosed as secondary compressive epidural tumors.

Acquired Immunodeficiency Syndrome↗
PubMed1996

AIDS-associated cytomegalovirus infection mimicking central nervous system tumors: a diagnostic challenge.

We reviewed cases of cytomegalovirus (CMV) infection of the central nervous system (CNS) that initially masqueraded as tumors in 37 of 543 consecutive patients infected with human immunodeficiency virus (HIV) and CMV who were seen at the Pasteur Institute Hospital and Saint-Louis Hospital (Paris) between 1992 and 1994. We detail the clinical features of three patients who presented with ring-enhanced space-occupying lesions mimicking CNS tumors. They were all profoundly immunodepressed (mean CD4 cell count, 13/mm3). Magnetic resonance imaging (MRI) showed enlargement of the spinal cord in one case, consistent with a space-occupying lesion and showing gadolinium enhancement; in the other two cases, ring-enhanced mass lesions were seen in the cerebral hemispheres. In all three cases marked edema and a mass effect were present. Image-guided stereotactic biopsies confirmed the diagnosis of CMV infection. The three patients' conditions improved with specific therapy. MRI showed enhanced focal intraparenchymal lesions consistent with marked focal necrosis, probably related to the severity of immunodepression, as HIV infection had been diagnosed several years previously. CMV infection should be considered as a cause of ring-enhanced space-occupying mass lesions in patients with HIV-1 infection. Earlier identification of these unusual tumorlike forms of CMV infection by means of MRI should result in improved outcome.

AIDS-Related Opportunistic Infections↗
PubMed1996

[Hypothermia and the nervous system. Review of the literature apropos of 4 cases].

Thermoregulation involves a long term adaptation system with hormonal processes and an immediate regulation system by extrapyramidal tracts, sympathetic part of autonomic nervous system and cortical integration of body temperature changes. Both system are under control of a hypothalamic center. Prolonged accidental exposure to intense cold and myxoedematous coma are the best known etiologies of hypothermia. However milder and often misdiagnosed hypothermia can occur at home in patients without endocrinologic disease. In these cases, hypothermia is due to dysfunction of immediate thermregulation under neuronal control, especially somatomotor and autonomic system. We report four cases of hypothermia of this kind. Two patients had an inhibition of peripherical mechanisms of protecting against cold (cutaneous vasoconstriction, shivering) and had dampened perception of cold: one was 73, had diabetes mellitus and took different drugs, the other one suffered from systemic lupus with myelopathy. The two other patients probably had a disorder of the thermoregulation hypothalamic center: one had Wernicke's encephalopathy and the other multiple sclerosis. From these cases and a review of the literature, we describe the different etiologies of hypothermia and their pathophysiology.

Adult↗