Alessandra Meroni - Academia.edu (original) (raw)

Papers by Alessandra Meroni

Epilepsia, Jun 1, 2006

We analyzed 26 surgically treated patients operated on for intractable epilepsy associated with t... more We analyzed 26 surgically treated patients operated on for intractable epilepsy associated with type IA (architectural) cortical dysplasia, to investigate neuropathologic and immunocytochemical features, particularly of the γaminobutyric acid (GABA)ergic system, and to compare the findings with those observed in normal cortex. Methods:. Routinely stained slides and serial sections immunostained for neurofilaments (SMI 311), microtubuleassociated protein-2 (MAP-2), neuron-specific nuclear protein (NeuN), glial fibrillary acidic protein (GFAP), parvalbumin (PV), calbindin (CB), and calretinin (CR) were processed. Some sections were processed by using single-immunoperoxidase procedures; others were processed for double immunofluorescence labelling and observed by confocal microscopy. The density of inhibitory PV-immunoreactive interneurons was quantitatively assessed in all patients and control cases by using a two-dimensional cell-counting technique on PV immunostained sections. Results: The density of PV-immunoreactive interneurons was significantly reduced in this group of patients, whereas CB-and CR-positivity appeared similar to those in normal cortex. In five cases, architectural abnormalities, in addition to those that defined type 1A dysplasia, were present and characterized by abnormal clusters of neurons and laminar cellular loss in superficial cortical laminate. Conclusions: The reduction of PV expression in type IA cortical dysplasia suggests an impairment of the GABAergic system as a possible mechanism for the epileptogenicity; in addition, PV immunoreactivity can be helpful in the neuropathologic characterization of this form of cortical dysplasia.

Epileptic Disorders, Dec 1, 2009

The present study included analysis of data from 243 patients surgically treated for Temporal Lob... more The present study included analysis of data from 243 patients surgically treated for Temporal Lobe Epilepsy (TLE). Resection was confined to the temporal lobe, with at least two years of follow-up, and specimens sufficiently preserved to allow a precise evaluation of both lateral neocortex and hippocampus. The frequency of different types of lesion and hippocampal sclerosis (HS), isolated or associated with neocortical lesions, risk factors and surgical outcomes in relation to neuropathological findings were evaluated. We found tumours in 33% of patients, malformations of cortical development (MCD) in 45%, isolated HS in 14%, no lesion in 5% and less common lesions in 3%. HS was present in 8% of tumour cases and 70% of MCD. Statistical analysis of antecedents was significantly associated only with febrile seizures (FS). In MCD patients with no history of FS, a strong association between HS and duration of epilepsy was revealed. A Class I outcome was identified in 87% of cases with tumours and 79% in cases with MCD. In 93 patients the antiepileptic drug therapy was withdrawn. Our findings show that MCD, which is significantly associated with HS, is the most common lesion in TLE and support the concept that an optimal outcome is obtained when mesial and neocortical structures are removed. FS are particularly relevant in patients with focal cortical dysplasia and HS. 1

European Journal of Neuroscience, Nov 1, 2004

Together with its adaptor protein, the adaptor protein of 12 kDa also known as KARAP and TYROBP (... more Together with its adaptor protein, the adaptor protein of 12 kDa also known as KARAP and TYROBP (DAP12), triggering r (TREM2) is a stimulatory membrane receptor of the immunoglobulin/lectin‐like superfamily, well known in myeloid cells. In humans, however, loss‐of‐function mutations of TREM2/DAP12 leave myeloid cells unaffected but induce an autosomal recessive disease characterized, together with bone cysts, by a spectrum of pathological lesions in the cortex, thalamus and basal ganglia with clinical symptoms of progressive dementia (polycystic lipomembraneous osteodysplasia with sclerosing leukoencephalopathy). Nothing was known about the role of TREM2/DAP12 in brain cell biology and physiology. By confocal immunocytochemistry we demonstrate that, in both human and mouse cerebral cortex, TREM2/DAP12, strongly expressed by microglia, is also present in a fraction of neurons but not in astrocytes and oligodendrocytes. In contrast, in the hippocampal cortex TREM2‐expressing neurons are rare. Both in neurons and microglia the receptor appears to be located mostly intracellularly in a discrete compartment(s) partially coinciding with (or adjacent to) the Golgi complex/trans‐Golgi network. Four nerve cell lines were identified as expressing the intracellular receptor system. In living human microglia CHME‐5 and glioblastoma T98G cells, activation of TREM2 by its specific antibody induced [Ca2+]i responses, documenting its surface expression and functioning. Surface expression of TREM2, low in resting CHME‐5 and T98G cells, increases significantly and transiently (60 min) when cells are stimulated by ionomycin, as revealed by both surface biotinylation and surface immunolabeling. Our results provide the first information about the expression, distribution (mostly intracellular) and functioning of TREM2/DAP12 system in nerve cells, a necessary step in the understanding of the cellular mechanisms affected in polycystic lipomembraneous osteodysplasia with sclerosing leukoencephalopathy.

Veterinary Research, 2006

The pathogenesis of encephalomyocarditis (EMC) due to the EMC virus (EMCV) was studied in 24 pigl... more The pathogenesis of encephalomyocarditis (EMC) due to the EMC virus (EMCV) was studied in 24 piglets oro-nasally infected with the field isolate B279/95. Two pigs were kept as negative controls and were euthanised at hour 0. The remaining 24 were euthanised every 6 h up to 78-h post infection (hpi). Virus isolation, histological examination and EMCV immunodetection were performed on the spleen, intestine, pancreas, liver, kidneys, heart, lungs, lymph nodes, tonsils and brain. EMCV was isolated at 6-hpi from the intestine and lymph nodes and at 12-hpi from the heart. From 6 to 12-hpi, scattered degenerate myocardiocytes were immunolabelled. Subsequently, myocarditis developed and progressively worsened. Immunopositive reaction in tonsil macrophages, observed in the early stage of infection (6-hpi), suggests that tonsils are the portal of entry, and by mean of wandering macrophages the EMC virus is then distributed through the body. Afterwards, EMCV-B279/95 replicates intensively in the cytoplasm of myocardiocytes and the acute myocarditis is strictly related to the tropism of these cells. Four pigs died spontaneously. In three animals no post mortem lesions or virus were isolated/detected, although all of them showed mild myocarditis. The experimental infection with EMCV B279/95 indicates: (i) the experimental protocol mimics the individual variability observed in natural disease, (ii) tonsils are the portal of entry of infection and the heart is the target organ, (iii) EMCV provides a valuable animal model for comparative studies on progressive viral myocarditis. encephalomyocarditis virus-EMCV / swine / myocarditis / immunohistochemistry

Epilepsia, 2009

SummaryPurpose: Despite the availability of detailed electroclinical and imaging data, only a fe... more SummaryPurpose: Despite the availability of detailed electroclinical and imaging data, only a few neuropathological studies of nodular heterotopia have been published. The aim of this study was to describe the neuropathological features of various types of nodular heterotopia obtained from patients undergoing surgery for intractable epilepsy.Methods: Specimens of heterotopic nodules taken from 24 patients were neuropathologically investigated using routine and immunocytochemical procedures, and the data were compared with magnetic resonance imaging (MRI), electroclinical findings, and surgical outcomes.Results: The neuropathological data distinguished two groups. Group 1 (14 patients, 78% in Engel class 1) had similar characteristics regardless of the size, number, or location of the nodules, with both projecting and local circuit neurons in the nodules intermingled with glial cells. Thirteen patients had focal cortical dysplasia. The nodules were identified by MRI in all cases. In group 2 (10 patients, 90% in Engel class 1), all of the nodules were within the temporal lobe and associated with hippocampal sclerosis or gangliogliomas. They were very small (undetected by MRI) and mainly formed by projecting neurons with no evidence of glial cells. All of the patients had cortical dysplasia.Discussion: The distinctive neuropathological features of the nodules in the two groups suggest different etiopathogenetic mechanisms. In group 2, the presence of nodular formations in association with cortical dysplasia and either hippocampal sclerosis or ganglioglioma raises a question concerning so‐called dual pathology in the temporal lobe.

Epileptic disorders : international epilepsy journal with videotape, 2009

The present study included analysis of data from 243 patients surgically treated for Temporal Lob... more The present study included analysis of data from 243 patients surgically treated for Temporal Lobe Epilepsy (TLE). Resection was confined to the temporal lobe, with at least two years of follow-up, and specimens sufficiently preserved to allow a precise evaluation of both lateral neocortex and hippocampus. The frequency of different types of lesion and hippocampal sclerosis (HS), isolated or associated with neocortical lesions, risk factors and surgical outcomes in relation to neuropathological findings were evaluated. We found tumours in 33% of patients, malformations of cortical development (MCD) in 45%, isolated HS in 14%, no lesion in 5% and less common lesions in 3%. HS was present in 8% of tumour cases and 70% of MCD. Statistical analysis of antecedents was significantly associated only with febrile seizures (FS). In MCD patients with no history of FS, a strong association between HS and duration of epilepsy was revealed. A Class I outcome was identified in 87% of cases with t...

Veterinary Research, 2006

The pathogenesis of encephalomyocarditis (EMC) due to the EMC virus (EMCV) was studied in 24 pigl... more The pathogenesis of encephalomyocarditis (EMC) due to the EMC virus (EMCV) was studied in 24 piglets oro-nasally infected with the field isolate B279/95. Two pigs were kept as negative controls and were euthanised at hour 0. The remaining 24 were euthanised every 6 h up to 78-h post infection (hpi). Virus isolation, histological examination and EMCV immunodetection were performed on the spleen, intestine, pancreas, liver, kidneys, heart, lungs, lymph nodes, tonsils and brain. EMCV was isolated at 6-hpi from the intestine and lymph nodes and at 12-hpi from the heart. From 6 to 12-hpi, scattered degenerate myocardiocytes were immunolabelled. Subsequently, myocarditis developed and progressively worsened. Immunopositive reaction in tonsil macrophages, observed in the early stage of infection (6-hpi), suggests that tonsils are the portal of entry, and by mean of wandering macrophages the EMC virus is then distributed through the body. Afterwards, EMCV-B279/95 replicates intensively in the cytoplasm of myocardiocytes and the acute myocarditis is strictly related to the tropism of these cells. Four pigs died spontaneously. In three animals no post mortem lesions or virus were isolated/detected, although all of them showed mild myocarditis. The experimental infection with EMCV B279/95 indicates: (i) the experimental protocol mimics the individual variability observed in natural disease, (ii) tonsils are the portal of entry of infection and the heart is the target organ, (iii) EMCV provides a valuable animal model for comparative studies on progressive viral myocarditis. encephalomyocarditis virus-EMCV / swine / myocarditis / immunohistochemistry

Journal of Neuropathology & Experimental Neurology, 2005

Epilepsy-associated malformations of cortical development (MCDs) comprise a variety of dysplastic... more Epilepsy-associated malformations of cortical development (MCDs) comprise a variety of dysplastic and neoplastic lesions of yet undetermined molecular pathology. Histopathologic similarities between MCDs and dysplastic brain lesions in the autosomal inherited neurocutaneous phacomatosis tuberous sclerosis (TSC), which affects the TSC1 and/or TSC2 genes, suggest common pathogenetic mechanisms. Previous studies revealed different alterations of TSC1 and TSC2 in epilepsy-associated malformations and glio-neuronal tumors despite histopathologic similarities. In order to examine current clinico-pathologic classification systems of cortical malformations on the molecular level, we carried out a mutational analysis of TSC1 and TSC2 in a series of surgical specimens obtained from patients with FCD without Taylor type balloon cells (FCD IIa ; n = 20), architectural dysplasias (FCD I ; n = 15), nodular cortical heterotopias (NCH; n = 4), and heterotopic white matter neurons (WMNH; n = 19). In FCD IIa , abundant genomic polymorphisms were detected in TSC2 (intron 4) but no allelic variants observed in exon 17 of TSC1. This allelic distribution pattern is in contrast to findings in FCD I and WMNH but also to those previously reported in FCD IIb (Taylor's balloon cell type). The latter revealed increased frequencies of specific alleles only in TSC1. The determination of characteristic molecular genetic alterations in specific epilepsy-associated malformations will support a comprehensive clinico-pathologic classification system and help to identify molecular pathways with potential pathogenetic relevance. Our work is supported by DFG (SFB TR3 [AJB], DFG Bl 421/1-1 [IB]), BONFOR, and Deutsche Krebshilfe.

European Journal of Neuroscience, 2004

Together with its adaptor protein, the adaptor protein of 12 kDa also known as KARAP and TYROBP (... more Together with its adaptor protein, the adaptor protein of 12 kDa also known as KARAP and TYROBP (DAP12), triggering r (TREM2) is a stimulatory membrane receptor of the immunoglobulin/lectin‐like superfamily, well known in myeloid cells. In humans, however, loss‐of‐function mutations of TREM2/DAP12 leave myeloid cells unaffected but induce an autosomal recessive disease characterized, together with bone cysts, by a spectrum of pathological lesions in the cortex, thalamus and basal ganglia with clinical symptoms of progressive dementia (polycystic lipomembraneous osteodysplasia with sclerosing leukoencephalopathy). Nothing was known about the role of TREM2/DAP12 in brain cell biology and physiology. By confocal immunocytochemistry we demonstrate that, in both human and mouse cerebral cortex, TREM2/DAP12, strongly expressed by microglia, is also present in a fraction of neurons but not in astrocytes and oligodendrocytes. In contrast, in the hippocampal cortex TREM2‐expressing neurons a...

Epilepsia, 2009

SummaryPurpose: Despite the availability of detailed electroclinical and imaging data, only a fe... more SummaryPurpose: Despite the availability of detailed electroclinical and imaging data, only a few neuropathological studies of nodular heterotopia have been published. The aim of this study was to describe the neuropathological features of various types of nodular heterotopia obtained from patients undergoing surgery for intractable epilepsy.Methods: Specimens of heterotopic nodules taken from 24 patients were neuropathologically investigated using routine and immunocytochemical procedures, and the data were compared with magnetic resonance imaging (MRI), electroclinical findings, and surgical outcomes.Results: The neuropathological data distinguished two groups. Group 1 (14 patients, 78% in Engel class 1) had similar characteristics regardless of the size, number, or location of the nodules, with both projecting and local circuit neurons in the nodules intermingled with glial cells. Thirteen patients had focal cortical dysplasia. The nodules were identified by MRI in all cases. In...

Epilepsia, 2006

Summary: Purpose: We analyzed 26 surgically treated patients operated on for intractable epileps... more Summary: Purpose: We analyzed 26 surgically treated patients operated on for intractable epilepsy associated with type IA (architectural) cortical dysplasia, to investigate neuropathologic and immunocytochemical features, particularly of the γ‐aminobutyric acid (GABA)ergic system, and to compare the findings with those observed in normal cortex. Methods:. Routinely stained slides and serial sections immunostained for neurofilaments (SMI 311), microtubule‐associated protein‐2 (MAP‐2), neuron‐specific nuclear protein (NeuN), glial fibrillary acidic protein (GFAP), parvalbumin (PV), calbindin (CB), and calretinin (CR) were processed. Some sections were processed by using single‐immunoperoxidase procedures; others were processed for double immunofluorescence labelling and observed by confocal microscopy. The density of inhibitory PV‐immunoreactive interneurons was quantitatively assessed in all patients and control cases by using a two‐dimensional cell‐counting technique on PV immunost...

europic.org.uk

... Antigenic characterisation: A panel of 40 MAbs were used in an antigen trapping ELISA as prev... more ... Antigenic characterisation: A panel of 40 MAbs were used in an antigen trapping ELISA as previously described (Koenen et al., 1997). ... Oligonucleotide primers were designed based on published sequences of EMCV strains; R, Mengo, B, D and PV21 (EMBL/GenBank/DDBJ ...

Epilepsia, Jun 1, 2006

We analyzed 26 surgically treated patients operated on for intractable epilepsy associated with t... more We analyzed 26 surgically treated patients operated on for intractable epilepsy associated with type IA (architectural) cortical dysplasia, to investigate neuropathologic and immunocytochemical features, particularly of the γaminobutyric acid (GABA)ergic system, and to compare the findings with those observed in normal cortex. Methods:. Routinely stained slides and serial sections immunostained for neurofilaments (SMI 311), microtubuleassociated protein-2 (MAP-2), neuron-specific nuclear protein (NeuN), glial fibrillary acidic protein (GFAP), parvalbumin (PV), calbindin (CB), and calretinin (CR) were processed. Some sections were processed by using single-immunoperoxidase procedures; others were processed for double immunofluorescence labelling and observed by confocal microscopy. The density of inhibitory PV-immunoreactive interneurons was quantitatively assessed in all patients and control cases by using a two-dimensional cell-counting technique on PV immunostained sections. Results: The density of PV-immunoreactive interneurons was significantly reduced in this group of patients, whereas CB-and CR-positivity appeared similar to those in normal cortex. In five cases, architectural abnormalities, in addition to those that defined type 1A dysplasia, were present and characterized by abnormal clusters of neurons and laminar cellular loss in superficial cortical laminate. Conclusions: The reduction of PV expression in type IA cortical dysplasia suggests an impairment of the GABAergic system as a possible mechanism for the epileptogenicity; in addition, PV immunoreactivity can be helpful in the neuropathologic characterization of this form of cortical dysplasia.

Epileptic Disorders, Dec 1, 2009

The present study included analysis of data from 243 patients surgically treated for Temporal Lob... more The present study included analysis of data from 243 patients surgically treated for Temporal Lobe Epilepsy (TLE). Resection was confined to the temporal lobe, with at least two years of follow-up, and specimens sufficiently preserved to allow a precise evaluation of both lateral neocortex and hippocampus. The frequency of different types of lesion and hippocampal sclerosis (HS), isolated or associated with neocortical lesions, risk factors and surgical outcomes in relation to neuropathological findings were evaluated. We found tumours in 33% of patients, malformations of cortical development (MCD) in 45%, isolated HS in 14%, no lesion in 5% and less common lesions in 3%. HS was present in 8% of tumour cases and 70% of MCD. Statistical analysis of antecedents was significantly associated only with febrile seizures (FS). In MCD patients with no history of FS, a strong association between HS and duration of epilepsy was revealed. A Class I outcome was identified in 87% of cases with tumours and 79% in cases with MCD. In 93 patients the antiepileptic drug therapy was withdrawn. Our findings show that MCD, which is significantly associated with HS, is the most common lesion in TLE and support the concept that an optimal outcome is obtained when mesial and neocortical structures are removed. FS are particularly relevant in patients with focal cortical dysplasia and HS. 1

European Journal of Neuroscience, Nov 1, 2004

Together with its adaptor protein, the adaptor protein of 12 kDa also known as KARAP and TYROBP (... more Together with its adaptor protein, the adaptor protein of 12 kDa also known as KARAP and TYROBP (DAP12), triggering r (TREM2) is a stimulatory membrane receptor of the immunoglobulin/lectin‐like superfamily, well known in myeloid cells. In humans, however, loss‐of‐function mutations of TREM2/DAP12 leave myeloid cells unaffected but induce an autosomal recessive disease characterized, together with bone cysts, by a spectrum of pathological lesions in the cortex, thalamus and basal ganglia with clinical symptoms of progressive dementia (polycystic lipomembraneous osteodysplasia with sclerosing leukoencephalopathy). Nothing was known about the role of TREM2/DAP12 in brain cell biology and physiology. By confocal immunocytochemistry we demonstrate that, in both human and mouse cerebral cortex, TREM2/DAP12, strongly expressed by microglia, is also present in a fraction of neurons but not in astrocytes and oligodendrocytes. In contrast, in the hippocampal cortex TREM2‐expressing neurons are rare. Both in neurons and microglia the receptor appears to be located mostly intracellularly in a discrete compartment(s) partially coinciding with (or adjacent to) the Golgi complex/trans‐Golgi network. Four nerve cell lines were identified as expressing the intracellular receptor system. In living human microglia CHME‐5 and glioblastoma T98G cells, activation of TREM2 by its specific antibody induced [Ca2+]i responses, documenting its surface expression and functioning. Surface expression of TREM2, low in resting CHME‐5 and T98G cells, increases significantly and transiently (60 min) when cells are stimulated by ionomycin, as revealed by both surface biotinylation and surface immunolabeling. Our results provide the first information about the expression, distribution (mostly intracellular) and functioning of TREM2/DAP12 system in nerve cells, a necessary step in the understanding of the cellular mechanisms affected in polycystic lipomembraneous osteodysplasia with sclerosing leukoencephalopathy.

Veterinary Research, 2006

The pathogenesis of encephalomyocarditis (EMC) due to the EMC virus (EMCV) was studied in 24 pigl... more The pathogenesis of encephalomyocarditis (EMC) due to the EMC virus (EMCV) was studied in 24 piglets oro-nasally infected with the field isolate B279/95. Two pigs were kept as negative controls and were euthanised at hour 0. The remaining 24 were euthanised every 6 h up to 78-h post infection (hpi). Virus isolation, histological examination and EMCV immunodetection were performed on the spleen, intestine, pancreas, liver, kidneys, heart, lungs, lymph nodes, tonsils and brain. EMCV was isolated at 6-hpi from the intestine and lymph nodes and at 12-hpi from the heart. From 6 to 12-hpi, scattered degenerate myocardiocytes were immunolabelled. Subsequently, myocarditis developed and progressively worsened. Immunopositive reaction in tonsil macrophages, observed in the early stage of infection (6-hpi), suggests that tonsils are the portal of entry, and by mean of wandering macrophages the EMC virus is then distributed through the body. Afterwards, EMCV-B279/95 replicates intensively in the cytoplasm of myocardiocytes and the acute myocarditis is strictly related to the tropism of these cells. Four pigs died spontaneously. In three animals no post mortem lesions or virus were isolated/detected, although all of them showed mild myocarditis. The experimental infection with EMCV B279/95 indicates: (i) the experimental protocol mimics the individual variability observed in natural disease, (ii) tonsils are the portal of entry of infection and the heart is the target organ, (iii) EMCV provides a valuable animal model for comparative studies on progressive viral myocarditis. encephalomyocarditis virus-EMCV / swine / myocarditis / immunohistochemistry

Epilepsia, 2009

SummaryPurpose: Despite the availability of detailed electroclinical and imaging data, only a fe... more SummaryPurpose: Despite the availability of detailed electroclinical and imaging data, only a few neuropathological studies of nodular heterotopia have been published. The aim of this study was to describe the neuropathological features of various types of nodular heterotopia obtained from patients undergoing surgery for intractable epilepsy.Methods: Specimens of heterotopic nodules taken from 24 patients were neuropathologically investigated using routine and immunocytochemical procedures, and the data were compared with magnetic resonance imaging (MRI), electroclinical findings, and surgical outcomes.Results: The neuropathological data distinguished two groups. Group 1 (14 patients, 78% in Engel class 1) had similar characteristics regardless of the size, number, or location of the nodules, with both projecting and local circuit neurons in the nodules intermingled with glial cells. Thirteen patients had focal cortical dysplasia. The nodules were identified by MRI in all cases. In group 2 (10 patients, 90% in Engel class 1), all of the nodules were within the temporal lobe and associated with hippocampal sclerosis or gangliogliomas. They were very small (undetected by MRI) and mainly formed by projecting neurons with no evidence of glial cells. All of the patients had cortical dysplasia.Discussion: The distinctive neuropathological features of the nodules in the two groups suggest different etiopathogenetic mechanisms. In group 2, the presence of nodular formations in association with cortical dysplasia and either hippocampal sclerosis or ganglioglioma raises a question concerning so‐called dual pathology in the temporal lobe.

Epileptic disorders : international epilepsy journal with videotape, 2009

The present study included analysis of data from 243 patients surgically treated for Temporal Lob... more The present study included analysis of data from 243 patients surgically treated for Temporal Lobe Epilepsy (TLE). Resection was confined to the temporal lobe, with at least two years of follow-up, and specimens sufficiently preserved to allow a precise evaluation of both lateral neocortex and hippocampus. The frequency of different types of lesion and hippocampal sclerosis (HS), isolated or associated with neocortical lesions, risk factors and surgical outcomes in relation to neuropathological findings were evaluated. We found tumours in 33% of patients, malformations of cortical development (MCD) in 45%, isolated HS in 14%, no lesion in 5% and less common lesions in 3%. HS was present in 8% of tumour cases and 70% of MCD. Statistical analysis of antecedents was significantly associated only with febrile seizures (FS). In MCD patients with no history of FS, a strong association between HS and duration of epilepsy was revealed. A Class I outcome was identified in 87% of cases with t...

Veterinary Research, 2006

The pathogenesis of encephalomyocarditis (EMC) due to the EMC virus (EMCV) was studied in 24 pigl... more The pathogenesis of encephalomyocarditis (EMC) due to the EMC virus (EMCV) was studied in 24 piglets oro-nasally infected with the field isolate B279/95. Two pigs were kept as negative controls and were euthanised at hour 0. The remaining 24 were euthanised every 6 h up to 78-h post infection (hpi). Virus isolation, histological examination and EMCV immunodetection were performed on the spleen, intestine, pancreas, liver, kidneys, heart, lungs, lymph nodes, tonsils and brain. EMCV was isolated at 6-hpi from the intestine and lymph nodes and at 12-hpi from the heart. From 6 to 12-hpi, scattered degenerate myocardiocytes were immunolabelled. Subsequently, myocarditis developed and progressively worsened. Immunopositive reaction in tonsil macrophages, observed in the early stage of infection (6-hpi), suggests that tonsils are the portal of entry, and by mean of wandering macrophages the EMC virus is then distributed through the body. Afterwards, EMCV-B279/95 replicates intensively in the cytoplasm of myocardiocytes and the acute myocarditis is strictly related to the tropism of these cells. Four pigs died spontaneously. In three animals no post mortem lesions or virus were isolated/detected, although all of them showed mild myocarditis. The experimental infection with EMCV B279/95 indicates: (i) the experimental protocol mimics the individual variability observed in natural disease, (ii) tonsils are the portal of entry of infection and the heart is the target organ, (iii) EMCV provides a valuable animal model for comparative studies on progressive viral myocarditis. encephalomyocarditis virus-EMCV / swine / myocarditis / immunohistochemistry

Journal of Neuropathology & Experimental Neurology, 2005

Epilepsy-associated malformations of cortical development (MCDs) comprise a variety of dysplastic... more Epilepsy-associated malformations of cortical development (MCDs) comprise a variety of dysplastic and neoplastic lesions of yet undetermined molecular pathology. Histopathologic similarities between MCDs and dysplastic brain lesions in the autosomal inherited neurocutaneous phacomatosis tuberous sclerosis (TSC), which affects the TSC1 and/or TSC2 genes, suggest common pathogenetic mechanisms. Previous studies revealed different alterations of TSC1 and TSC2 in epilepsy-associated malformations and glio-neuronal tumors despite histopathologic similarities. In order to examine current clinico-pathologic classification systems of cortical malformations on the molecular level, we carried out a mutational analysis of TSC1 and TSC2 in a series of surgical specimens obtained from patients with FCD without Taylor type balloon cells (FCD IIa ; n = 20), architectural dysplasias (FCD I ; n = 15), nodular cortical heterotopias (NCH; n = 4), and heterotopic white matter neurons (WMNH; n = 19). In FCD IIa , abundant genomic polymorphisms were detected in TSC2 (intron 4) but no allelic variants observed in exon 17 of TSC1. This allelic distribution pattern is in contrast to findings in FCD I and WMNH but also to those previously reported in FCD IIb (Taylor's balloon cell type). The latter revealed increased frequencies of specific alleles only in TSC1. The determination of characteristic molecular genetic alterations in specific epilepsy-associated malformations will support a comprehensive clinico-pathologic classification system and help to identify molecular pathways with potential pathogenetic relevance. Our work is supported by DFG (SFB TR3 [AJB], DFG Bl 421/1-1 [IB]), BONFOR, and Deutsche Krebshilfe.

European Journal of Neuroscience, 2004

Together with its adaptor protein, the adaptor protein of 12 kDa also known as KARAP and TYROBP (... more Together with its adaptor protein, the adaptor protein of 12 kDa also known as KARAP and TYROBP (DAP12), triggering r (TREM2) is a stimulatory membrane receptor of the immunoglobulin/lectin‐like superfamily, well known in myeloid cells. In humans, however, loss‐of‐function mutations of TREM2/DAP12 leave myeloid cells unaffected but induce an autosomal recessive disease characterized, together with bone cysts, by a spectrum of pathological lesions in the cortex, thalamus and basal ganglia with clinical symptoms of progressive dementia (polycystic lipomembraneous osteodysplasia with sclerosing leukoencephalopathy). Nothing was known about the role of TREM2/DAP12 in brain cell biology and physiology. By confocal immunocytochemistry we demonstrate that, in both human and mouse cerebral cortex, TREM2/DAP12, strongly expressed by microglia, is also present in a fraction of neurons but not in astrocytes and oligodendrocytes. In contrast, in the hippocampal cortex TREM2‐expressing neurons a...

Epilepsia, 2009

SummaryPurpose: Despite the availability of detailed electroclinical and imaging data, only a fe... more SummaryPurpose: Despite the availability of detailed electroclinical and imaging data, only a few neuropathological studies of nodular heterotopia have been published. The aim of this study was to describe the neuropathological features of various types of nodular heterotopia obtained from patients undergoing surgery for intractable epilepsy.Methods: Specimens of heterotopic nodules taken from 24 patients were neuropathologically investigated using routine and immunocytochemical procedures, and the data were compared with magnetic resonance imaging (MRI), electroclinical findings, and surgical outcomes.Results: The neuropathological data distinguished two groups. Group 1 (14 patients, 78% in Engel class 1) had similar characteristics regardless of the size, number, or location of the nodules, with both projecting and local circuit neurons in the nodules intermingled with glial cells. Thirteen patients had focal cortical dysplasia. The nodules were identified by MRI in all cases. In...

Epilepsia, 2006

Summary: Purpose: We analyzed 26 surgically treated patients operated on for intractable epileps... more Summary: Purpose: We analyzed 26 surgically treated patients operated on for intractable epilepsy associated with type IA (architectural) cortical dysplasia, to investigate neuropathologic and immunocytochemical features, particularly of the γ‐aminobutyric acid (GABA)ergic system, and to compare the findings with those observed in normal cortex. Methods:. Routinely stained slides and serial sections immunostained for neurofilaments (SMI 311), microtubule‐associated protein‐2 (MAP‐2), neuron‐specific nuclear protein (NeuN), glial fibrillary acidic protein (GFAP), parvalbumin (PV), calbindin (CB), and calretinin (CR) were processed. Some sections were processed by using single‐immunoperoxidase procedures; others were processed for double immunofluorescence labelling and observed by confocal microscopy. The density of inhibitory PV‐immunoreactive interneurons was quantitatively assessed in all patients and control cases by using a two‐dimensional cell‐counting technique on PV immunost...

europic.org.uk

... Antigenic characterisation: A panel of 40 MAbs were used in an antigen trapping ELISA as prev... more ... Antigenic characterisation: A panel of 40 MAbs were used in an antigen trapping ELISA as previously described (Koenen et al., 1997). ... Oligonucleotide primers were designed based on published sequences of EMCV strains; R, Mengo, B, D and PV21 (EMBL/GenBank/DDBJ ...