588 research outputs found

    Is there a role for <i>Mycobacterium avium</i> subspecies <i>paratuberculosis</i> in Parkinson's disease?

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    In Parkinson's disease (PD) ZnT proteins play an important role. Zinc is a co-factor of numerous enzymes and stabilizes the tertiary structure of several proteins. Nothing is known about previous infections mediated by Mycobacterium avium subsp. paratuberculosis (MAP). We evaluated if a previous infection with MAP could induce the production of antibodies that cross-reacted with the Znt homologous antigenic peptides associated to Parkinson. The humoral response toward MAP3865c peptides, ZnT3 and ZnT10 was evaluated. The hypothesis of cross-reactivity needs to be confirmed; we have observed the presence of MAP in PD patients by PCR, positivity to MAP3865c peptides, therefore MAP infection but not cross-reaction with human homologous Znt proteins

    Visual and auditory event related potentials in Amyotrophic Lateral Sclerosis

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    Amyotrophic lateral sclerosis (ALS) is classically described as an upper and lower motor neuron disease without clinical sensory disorders. Various studies have been conducted to explore and understand motor impairment but in the last years also cognitive functions have drawn attention in ALS patients investigating extra-motor involvment. Recent neuropsychological studies have been carried out to evaluate specific cognitive dysfunction also supported by MRI, PET and SPECI findings. All papers report subtle cognitive impairment especially related to the frontal lobe functions. Gil et al (1995) performed an auditory ERPs study and they found 60% of patients had P300 delayed latency. To further investigate the relationship between ALS and cognitive function, visual and auditory oddball ERPs were recorded in 10 patients by using 30 electrodes. Attention was focused on latency and amplitude of P300 and on its topographic distribution. Neuropsychological evaluation allowed to test the cognitive status of patients and psychometric tests were selected to assess intelligence, executive functions, attention, memory, word fluency, visuo-motor and visual-constructive skills. Motor disability was scored by ALS Severity Scale including bulbar and spinal score. Depression state was evaluated by using Hamilton Scale. Results of ERPs were compared to 10 healthy age-matched controls. Preliminary data show abnormalities of P300 in about 50% of patients. Correlations between visual and auditory P300 latency and amplitude, psychometric tests, disease duration, physical disability and depression will be discussed

    Visual and auditory event-related potentials in sporadic amyotrophic lateral sclerosis

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    Objectives: To investigate the relationship between amyotrophic lateral sclerosis (ALS) and cognitive function by means of oddball event-related potentials (ERPs) and to determine the usefulness of this methodology in the cognitive status assessment of physically disabled patients. Methods: Visual and auditory oddball ERPs were recorded in 16 consecutive sporadic ALS patients. A comprehensive battery of neuropsychological (NP) tests assessed intelligence, executive functions, attention, memory, word fluency, visuo-motor and visual-constructive skills. Results: All patients performed visual and auditory ERPs and 75% of cases showed abnormal N200 and/or P300 waves. Ten patients (62.5%) carried out the entire psychometric evaluation with significant impairment on tests of executive function and attention. A significant correlation between delayed visual (P&lt;0.04) and auditory (P&lt;0.04) P300 latency and impaired NP tests was found. Conclusions: In agreement with literature data, our findings confirm the hypothesis of cognitive impairment in ALS patients especially on attention and executive functions suggesting a more extensive degeneration beyond the motor areas. ALS causes severe physical disabilities and such a condition may interfere with NP testing. Thus, the P300 seems to be a useful tool for the assessment of cognition and attention when severe physical deficits are present.</br

    Comparison of two neural network classifiers in the differential diagnosis of essential tremor and Parkinson’s disease by <sup>123</sup>I-FP-CIT brain SPECT

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    Purpose : To contribute to the differentiation of Parkinson’s disease (PD) and essential tremor (ET), we compared two different artificial neural network classifiers using 123I-FP-CIT SPECT data, a probabilistic neural network (PNN) and a classification tree (ClT). Methods: 123I-FP-CIT brain SPECT with semiquantitative analysis was performed in 216 patients: 89 with ET, 64 with PD with a Hoehn and Yahr (H&amp;Y) score of ≤2 (early PD), and 63 with PD with a H&amp;Y score of ≥2.5 (advanced PD). For each of the 1,000 experiments carried out, 108 patients were randomly selected as the PNN training set, while the remaining 108 validated the trained PNN, and the percentage of the validation data correctly classified in the three groups of patients was computed. The expected performance of an “average performance PNN” was evaluated. In analogy, for ClT 1,000 classification trees with similar structures were generated. Results: For PNN, the probability of correct classification in patients with early PD was 81.9±8.1% (mean±SD), in patients with advanced PD 78.9±8.1%, and in ET patients 96.6±2.6%. For ClT, the first decision rule gave a mean value for the putamen of 5.99, which resulted in a probability of correct classification of 93.5±3.4%. This means that patients with putamen values &gt;5.99 were classified as having ET, while patients with putamen values &lt;5.99 were classified as having PD. Furthermore, if the caudate nucleus value was higher than 6.97 patients were classified as having early PD (probability 69.8±5.3%), and if the value was &lt;6.97 patients were classified as having advanced PD (probability 88.1%±8.8%). Conclusion: These results confirm that PNN achieved valid classification results. Furthermore, ClT provided reliable cut-off values able to differentiate ET and PD of different severities

    Neuropsychophysiological findings in a case of long-standing overt ventriculomegaly (LOVA)

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    Long-standing overt ventriculomegaly in adults (LOVA) is a clinical entity characterized by chronic hydrocephalus with infant onset, slow evolution and clinical disturbances during adulthood. Few cases are reported in literature describing the evident contrast between the severity of hydrocephalus and the relatively spared neurological functioning and cognitive aspects. The authors describe a 59-year-old man with congenital hydrocephalus complaining of persistent gait impairment. Neurological examination showed a mild paraparesis, severe higher cortical function impairment but relatively sparing of daily living activity. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a very remarkable ventriculomegaly compressing the brain cortex but sparing the cerebellum and the brainstem. Brain Single Photon Emission Computer Tomography (SPECT) showed a prevalent cerebellar perfusion as well. Neuropsychological testing was consistent with severe cognitive deterioration and attention disorders. Language and praxis functions seemed to be preserved. Auditory oddball ERPs (P300) showed morphological abnormalities especially of late components. This case report demonstrates in vivo the level of adaptation to which human brain can reach under chronic mechanic stress conditions. The striking poor cerebral parenchyma representation and the relatively spared language and praxic abilities account for a functional reorganization of residual structures due to the neural plasticity

    Longitudinal study of cognitive dysfunction in multiple sclerosis: neuropsychological, neuroradiological, and neurophysiological findings

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    Objective: (1) To assess cognitive function and cerebral magnetic resonance imaging (MRI) involvement in relapsing-remitting multiple sclerosis; (2) to monitor disease evolution, cognitive dysfunction, and cerebral lesion burden over time (mean 8.5 year follow up period); (3) to study the relation between clinical, neuropsychological, and MRI data. On follow up assessment, visual and auditory oddball event related potentials (ERPs) were recorded as psychophysiological evaluation of cognitive status. Correlations between neuropsychological, MRI, and ERP data were also analysed. Methods: Neuropsychological study assessed verbal and non-verbal IQ, deterioration index (DI) from WAIS subtests, conceptual reasoning, attention, verbal and visuospatial short-term and long term memory. MRI assessment detected presence of demyelinating lesions by using a semiquantitative method as well as cortical and subcortical atrophy over time. Results: Attention, short-term and long term visuospatial memory were mildly impaired at baseline and remained unaltered longitudinally. At retesting a significant worsening of verbal long term memory (p=0.023), DI presence (p=0.041) and the increase of supratentorial and subtentorial MRI lesions load (p=0.001) emerged. Expanded disability status scale score correlated significantly with total lesion burden at both evaluations (p=0.043 and p=0.024 respectively). Temporal, occipital, and frontal horn lesions as well as cortical atrophy correlated significantly with attention and memory tests at baseline. Follow up assessment revealed significant correlation between cortical atrophy and attention as well as visuospatial short-term memory; spatial long term memory correlated significantly with lesions in body of lateral ventricle and frontal lobe. ERP study showed P300 latency abnormalities in 75% of patients, involving specifically more visual P300 (58.4 % of cases) than auditory wave (41.6 %). Visual P300 latency and amplitude correlated significantly with DI and auditory P300 latency with frontal horn and brain stem lesions. Conclusions: These findings revealed mild cognitive impairment in MS patients particularly consistent with slowing information processing over time. Increased MRI lesions do not correlate with the clinical course of the disease and cognitive deficit evolution. Thus, cognitive dysfunction could be related to disease peculiarity and not to the time course. Correlations between P300, neuropsychological, and MRI findings provide further information about ERP application to examine cognitive impairment in MS and probably to investigate their neural origin.</br

    Investigating the nature of the K∗0(700) state with π±K0S correlations at the LHC

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    The first measurements of femtoscopic correlations with the particle pair combinations π±K0S in pp collisions at s√=13 TeV at the Large Hadron Collider (LHC) are reported by the ALICE experiment. Using the femtoscopic approach, it is shown that it is possible to study the elusive K∗0(700) particle that has been considered a tetraquark candidate for over forty years. Boson source parameters and final-state interaction parameters are extracted by fitting a model assuming a Gaussian source to the experimentally measured two-particle correlation functions. The final-state interaction is modeled through a resonant scattering amplitude, defined in terms of a mass and a coupling parameter, decaying into a π±K0S pair. The extracted mass and Breit-Wigner width, derived from the coupling parameter, of the final-state interaction are found to be consistent with previous measurements of the K∗0(700). The small value and increasing behavior of the correlation strength with increasing source size support the hypothesis that the K∗0(700) is a four-quark state, i.e. a tetraquark state. This latter trend is also confirmed via a simple geometric model that assumes a tetraquark structure of the K∗0(700) resonance

    Investigating the nature of the K0(700)^*_0(700) state with π±\pi^\pmKS0^0_{\rm S} correlations at the LHC

    No full text
    International audienceThe first measurements of femtoscopic correlations with the particle pair combinations π±\pi^\pmKS0^0_{\rm S} in pp collisions at s=13\sqrt{s}=13 TeV at the Large Hadron Collider (LHC) are reported by the ALICE experiment. Using the femtoscopic approach, it is shown that it is possible to study the elusive K0(700)^*_0(700) particle that has been considered a tetraquark candidate for over forty years. Boson source parameters and final-state interaction parameters are extracted by fitting a model assuming a Gaussian source to the experimentally measured two-particle correlation functions. The final-state interaction is modeled through a resonant scattering amplitude, defined in terms of a mass and a coupling parameter, decaying into a π±\pi^\pmKS0^0_{\rm S} pair. The extracted mass and Breit-Wigner width, derived from the coupling parameter, of the final-state interaction are found to be consistent with previous measurements of the K0(700)^*_0(700). The small value and increasing behavior of the correlation strength with increasing source size support the hypothesis that the K0(700)^*_0(700) is a four-quark state, i.e. a tetraquark state. This latter trend is also confirmed via a simple geometric model that assumes a tetraquark structure of the K0(700)^*_0(700) resonance

    Investigating the nature of the K0^*_0(700) state with π±\pi^\pmKS0^0_{\rm S} correlations at the LHC

    No full text
    The first measurements of femtoscopic correlations with the particle pair combinations π±\pi^\pmKS0^0_{\rm S} in pp collisions at s=13\sqrt{s}=13 TeV at the Large Hadron Collider (LHC) are reported by the ALICE experiment. Using the femtoscopic approach, it is shown that it is possible to study the elusive K0(700)^*_0(700) particle that has been considered a tetraquark candidate for over forty years. Boson source parameters and final-state interaction parameters are extracted by fitting a model assuming a Gaussian source to the experimentally measured two-particle correlation functions. The final-state interaction is modeled through a resonant scattering amplitude, defined in terms of a mass and a coupling parameter, decaying into a π±\pi^\pmKS0^0_{\rm S} pair. The extracted mass and Breit--Wigner width, derived from the coupling parameter, of the final-state interaction are found to be consistent with previous measurements of the K0(700)^*_0(700). The small value and increasing behavior of the correlation strength with increasing source size support the hypothesis that the K0(700)^*_0(700) is a four-quark state, i.e. a tetraquark state. This latter trend is also confirmed via a simple geometric model that assumes a tetraquark structure of the K0(700)^*_0(700) resonance.The first measurements of femtoscopic correlations with the particle pair combinations π±\pi^\pmKS0^0_{\rm S} in pp collisions at s=13\sqrt{s}=13 TeV at the Large Hadron Collider (LHC) are reported by the ALICE experiment. Using the femtoscopic approach, it is shown that it is possible to study the elusive K0(700)^*_0(700) particle that has been considered a tetraquark candidate for over forty years. Boson source parameters and final-state interaction parameters are extracted by fitting a model assuming a Gaussian source to the experimentally measured two-particle correlation functions. The final-state interaction is modeled through a resonant scattering amplitude, defined in terms of a mass and a coupling parameter, decaying into a π±\pi^\pmKS0^0_{\rm S} pair. The extracted mass and Breit-Wigner width, derived from the coupling parameter, of the final-state interaction are found to be consistent with previous measurements of the K0(700)^*_0(700). The small value and increasing behavior of the correlation strength with increasing source size support the hypothesis that the K0(700)^*_0(700) is a four-quark state, i.e. a tetraquark state. This latter trend is also confirmed via a simple geometric model that assumes a tetraquark structure of the K0(700)^*_0(700) resonance

    Investigating the nature of the K0(700)^*_0(700) state with π±\pi^\pmKS0^0_{\rm S} correlations at the LHC

    No full text
    International audienceThe first measurements of femtoscopic correlations with the particle pair combinations π±\pi^\pmKS0^0_{\rm S} in pp collisions at s=13\sqrt{s}=13 TeV at the Large Hadron Collider (LHC) are reported by the ALICE experiment. Using the femtoscopic approach, it is shown that it is possible to study the elusive K0(700)^*_0(700) particle that has been considered a tetraquark candidate for over forty years. Boson source parameters and final-state interaction parameters are extracted by fitting a model assuming a Gaussian source to the experimentally measured two-particle correlation functions. The final-state interaction is modeled through a resonant scattering amplitude, defined in terms of a mass and a coupling parameter, decaying into a π±\pi^\pmKS0^0_{\rm S} pair. The extracted mass and Breit-Wigner width, derived from the coupling parameter, of the final-state interaction are found to be consistent with previous measurements of the K0(700)^*_0(700). The small value and increasing behavior of the correlation strength with increasing source size support the hypothesis that the K0(700)^*_0(700) is a four-quark state, i.e. a tetraquark state. This latter trend is also confirmed via a simple geometric model that assumes a tetraquark structure of the K0(700)^*_0(700) resonance
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