Search PubMed⌕ Search

Biomedical subjects

N Kopp

Publications and source records attributed to N Kopp.

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

Ultrastructural pathology of Creutzfeldt-Jakob disease and fatal familial insomnia.

In this study we examined well fixed brain biopsies of 9 sporadic CJD, 9 iatrogenic CJD cases, 2 hereditary CJD (Gly200Lys and Val203Iso), a case of vCJD and a case of fatal familial insomnia (FFI) from a new French family collected over the years at the Service de Neuropathologie, Hopital Neurologique, Lyon, France. Tubulovesicular structures (TVS) were found in every case including FFI and nvCJD. Thus, TVS, as we suggested previously are important pathologic structure which significance should be more extensively studied.

Amino Acid Substitution↗
PubMed1999

[Cerebral intravascular lymphoma during T CD4+ idiopathic lymphopenia syndrome].

BACKGROUND: Intravascular lymphoma is a proliferation of lymphoid cells, usually B cells, in small vessels, predominantly in the nervous system and skin. CASE REPORT: We report a case of a man with a 3-year history of lymphopenia with no detectable etiology (all viral causes were ruled out) who developed intravascular lymphoma in the cerebral vessels. DISCUSSION: This case was particular as the patient had idiopathic CD4+ lymphopenia. It points out the probable role of immunodepression in the development of lymphomas, particularly in endovascular localizations.

Aged↗
PubMed1999

Alternative exon 3 splicing of the human major protein zero gene in white blood cells and peripheral nerve tissue.

The major protein zero (MPZ) is involved in peripheral myelin folding. Using nested reverse transcription-PCR, we amplified several fragments of MPZ mRNAs in white blood cells and in peripheral nerve tissue. Cloning of PCR products revealed the existence of three alternative splicing patterns: one resulted in the complete loss of exon 3 and two others induced partial skipping of the exon 3 sequence. All three alternative splicing mechanisms produced a frame-shift and created an identical premature stop codon in exon 4. We conclude that the existence of these MPZ RNA transcript variants may be the result of deliberate splicing decisions and may have functional implications in the cell.

Actins↗
PubMed1999

Submicroscopic immunodetection of PrP in the brain of a patient with a new-variant of Creutzfeldt-Jakob disease.

We analyzed the distribution and organization of the pathological prion protein isoform (PrPsc) in the brain of new variant Creutzfeldt-Jakob disease using a sensitive post-embedding immunogold electron microscopy method. On methacrylate semithin sections, silver-PrP staining showed florid plaques, containing microvacuoles. It also revealed scattered granular and perivacuolar deposits. At the electron microscope level, plaque PrP-gold labeling was associated with filaments and flocculent amorphous material sometimes observed inside microvacuoles, considered as degenerative neurites. Outside the plaques, PrP-gold labeling was predominantly found over flocculent amorphous material and the presynaptic domain of synapses. Some lysosome-like organelles seen in the neuron perikaryon, were also found to be PrP-immunoreactive. These results are consistent with the hypothesis that the synapse is a privileged target in prion disease.

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

Classification of sporadic Creutzfeldt-Jakob disease based on molecular and phenotypic analysis of 300 subjects.

Phenotypic heterogeneity in sporadic Creutzfeldt-Jakob disease (sCJD) is well documented, but there is not yet a systematic classification of the disease variants. In a previous study, we showed that the polymorphic codon 129 of the prion protein gene (PRNP), and two types of protease-resistant prion protein (PrP(Sc)) with distinct physicochemical properties, are major determinants of these variants. To define the full spectrum of variants, we have examined a series of 300 sCJD patients. Clinical features, PRNP genotype, and PrP(Sc) properties were determined in all subjects. In 187, we also studied neuropathological features and immunohistochemical pattern of PrP(Sc) deposition. Seventy percent of subjects showed the classic CJD phenotype, PrP(Sc) type 1, and at least one methionine allele at codon 129; 25% of cases displayed the ataxic and kuru-plaque variants, associated to PrP(Sc) type 2, and valine homozygosity or heterozygosity at codon 129, respectively. Two additional variants, which included a thalamic form of CJD and a phenotype characterized by prominent dementia and cortical pathology, were linked to PrP(Sc) type 2 and methionine homozygosity. Finally, a rare phenotype characterized by progressive dementia was linked to PrP(Sc) type 1 and valine homozygosity. The present data demonstrate the existence of six phenotypic variants of sCJD. The physicochemical properties of PrP(Sc) in conjunction with the PRNP codon 129 genotype largely determine this phenotypic variability, and allow a molecular classification of the disease variants.

Adult↗
PubMed1999

Protection of personnel and environment against Creutzfeldt-Jakob disease in pathology laboratories.

Most neuropathology laboratories have been faced with the question of dealing with cases of Creutzfeldt-Jakob disease (CJD) which is a rare neurodegenerative disorder. Neuropathologists have been long aware of the transmissibility and unique properties of the agent which make it resistant to conventional inactivating reagents. The emergence of iatrogenic cases and of the bovine spongiform encephalopathy (BSE) crisis has induced anxiety among laboratory staff and raised questions about the efficiency of safety measures and procedures hitherto applied in pathology laboratories. This article aims at presenting an overview of the risk involved in handling CJD material. It gives practical advice and a key to more detailed procedures, guidelines and recommendations available in scientific literature and through government agencies. Neuropathologists and biochemists are at a higher potential risk than others since the diagnosing of CJD involves the handling of nervous tissue which contains the highest levels of infectivity.

Animals↗
PubMed1999

[JC virus infection and lympho-plasmocytic infiltration of the central nervous system revealed by a cerebellar syndrome].

We report the case of a 74 year-old woman who had been treated since 8 years for a Waldenström's disease. She also was affected by a progressive multi-focal leukoencephalopathy. The interest of this case lies in two principal features. On the one hand, the clinical and radiological signs were restricted to the cerebellum and to the brainstem, on the other hand, brain examination revealed lymphocytes and plasma cells infiltration suggestive of an associated Bing and Neel syndrome.

Aged↗
PubMed1999

Giant cell angiitis of the central nervous system with amyloid angiopathy. A case report and review of the literature.

We report a new case of giant cell angiitis of the central nervous system associated with cerebral amyloid angiopathy (GA/CAA). A 67-year-old woman was hospitalized with a history of headaches and lapses of consciousness. After improvement with corticosteroidtherpay, treatment was stopped. She relapsed and died 33 days after first admission. Pathological examination showed unusual extension of GA/CAA lesions, in the superficial and deep layer of the cerebral cortex, and in the cerebellum. Simultaneous occurrence of GA and CAA is rare. Histopathologic findings and immunological pathogenesis of the process are discussed: 1) arguments over pre-existence of CAA, responsible for GA; 2) primitive inflammatory process inducing amyloid deposits; 3) GA/CAA may represent an association of histological lesions related to 2 different types of disease: i) neurodegenerative disease with specific lesions (such as presence of diffuse senile plaques and neurofibrillary tangles) inducing inflammatory reaction ii) inflammatory disease, with few or no degenerative lesions, responding to immunotherapy.

Aged↗
PubMed1999

Benzodiazepine binding sites in the human hypothalamus. Autoradiographic study.

Using in vitro labelling and autoradiographic techniques, we have analyzed the fine and the detailed distribution of benzodiazepine binding sites in the post-mortem human hypothalamus. Binding sites were labelled in mounted tissue sections from adult brains, using the selective high affinity ligand [3H]-Flunitrazepam. A heterogeneous distribution of benzodiazepine binding sites was found throughout the rostrocaudal extent of human hypothalamus. The autoradiographic labelling was shown in the three hypothalamic parts, i.e., anterior, mediobasal and posterior levels. At the anterior level, the highest densities were present in the diagonal band of Broca, the preoptic area (medial and lateral parts) and the septohypothalamic nucleus. At the mediobasal hypothalamic level, the highest densities were mainly localized in the ventromedial nucleus, whereas the other structures were moderately labelled with [3H]-Flunitrazepam. The mammillary complex as well as the posterior hypothalamic area represented the most heavily labelled structures in the posterior hypothalamus. The results obtained in this study, indicate the presence of a large and heterogeneous distribution of benzodiazepine binding sites in human adult hypothalamus. This could support their implication in the control of distinct neural functions (like neuroendocrine role).

Adult↗
PubMed1998

Evaluation of endozepine-like immunoreactivity in the frontal cortex of suicide victims.

Diazepam-binding inhibitor (DBI) and its processing products, including the octadecaneuropeptide (ODN), are polypeptides called endozepines which have multiple biological effects, including regulation of mitochondrial steroidogenesis and modulation of GABA-gated chloride channels. Concentrations of ODN-like immunoreactivity (ODN-Li) were measured by radioimmunoassay in the frontal cortex of nine drug-free suicides and nine drug-free sudden-death victims. The level of ODN-Li was higher in the right than in the left frontal cortex, in both suicide (p < 0.05) and control (p < 0.02) subjects. No significant differences were found between suicides and controls either in the right and left cortex, or when considering the gender and the post-mortem diagnosis of depression.

Adult↗
PubMed1997

Autoradiographic distribution of brainstem substance P binding sites in humans: ontogenic study and relation to sudden infant death syndrome (SIDS).

The precise distribution of substance P (SP) binding sites in the human brainstem was investigated in normal cases (3 fetuses and 24 new-borns) and in 9 cases of Sudden Infant Death Syndrome (SIDS) by in vitro quantitative autoradiography. We discussed the widely but uneven distribution of SP binding sites as regards to the role of SP in brainstem cardio-respiratory ontogenic control and its possible involvement in SIDS.

Autoradiography↗
PubMed1996

Evidence for multiple opioid receptors in the human posterior pituitary.

The distribution and quantification of opioid receptor types in post-mortem human pituitary cryostat sections was determined by quantitative in vitro receptor autoradiography. Highly specific radioligands were used for each opioid receptor type i.e. [125l]-FK-33-824 for mu-opioid sites, [125l][D.Ala2]-Deltorphin-l for delta-opioid sites and 3H-U69,593 for kappa-opioid sites. None of the five specimens tested exhibited any labeling in the anterior lobe of the pituitary for the three radioligands. As for the posterior pituitary, all 5 specimens contained both mu and kappa-opioid binding sites whereas none of them showed delta-binding sites. The presence of both mu- and kappa-opioid binding sites in the human posterior pituitary contrasts with previous findings in the rat where only kappa-sites have been found. The present study could contribute to understanding of the functional action of opioids in the human pituitary.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1995

Regional distribution of substance P binding sites in the brainstem of the human newborn.

The distribution of [3H]substance P ([3H]SP) binding sites in the brainstem of the human newborn was investigated in eleven cases (aged 1 h to 6 months) by in vitro quantitative receptor autoradiography. The binding of [3H]SP to newborn brainstem tissue was found to be saturable (for the eight cases examined, Kd and Bmax (M +/- S.E.M.) were 0.29 +/- 0.03 nM and 206 +/- 21 fmol/mg tissue, respectively). Competition studies showed unlabeled SP to be the most potent peptide for displacing [3H]SP binding from tissue sections. The desaturating effect of GTP on the specific binding of [3H]SP was also investigated, but was not found to be significant. Autoradiographic analysis showed that the neurokinin-1 (NK-1)/SP binding sites were widely but unevenly distributed, and that they varied with age. The highest densities of (NK-1)/SP binding sites were observed in the locus coeruleus, olivaris inferior nuclei, raphe magnus and obscurus nuclei, while low to moderate densities were observed in other brainstem structures. These findings support the idea that SP is involved in cardiovascular regulation, and that it may interact with the catecholaminergic and/or serotonergic system.

Autoradiography↗