211 research outputs found

    Thalamic Atrophy in Huntington's Disease Co-varies with Cognitive Performance: A Morphometric MRI Analysis

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    The pattern of motor, behavioral and cognitive symptoms in Huntington's disease (HD) implicates dysfunction of basal-ganglia-thalamo-cortical circuits. This study explored if cognitive performance in HD is correlated with localized cerebral changes. Psychomotor functions were investigated by verbal fluency, Stroop color word and Digit Symbol tests in 44 HD patients and 22 controls. Three-dimensional magnetic resonance imaging (MRI) data were analyzed with regard to regional gray matter changes by use of the observer-independent whole-brain-based approach of voxel-based morphometry (VBM). Using statistical parametric mapping, the MRI data of the HD patients were analyzed in an ANCOVA including the individual results of the neuropsychological tests. Besides striatal areas, symmetrical regional atrophy of the thalamus was found to co-vary significantly with cognitive performance (P < 0.001, corrected for multiple comparisons). In particular, thalamic subnuclei projecting to prefrontal areas (dorsomedial subnucleus) and connected to the striatum (centromedian/parafascicular and ventrolateral nuclear complex) displayed volume loss, in agreement with neuropathological studies. These results suggest that thalamic degeneration contributes in an important way to the impairment of executive function in early HD. Patients who are impaired in executive tests display structural double lesions of the basal-ganglia-thalamo-cortical circuitry both at the striatal and at the thalamic leve

    Caudate Nucleus and Insular Activation During a Pain Suppression Paradigm Comparing Thermal and Electrical Stimulation

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    Pain modulation is an integral function of the nervous system. It is needed to adapt to chronic stimuli. To gain insights into pain suppression mechanisms, two studies concerning the suppression of the feeling of pain with different stimulation modalities (heat vs. electrical stimuli) but using the same stimulation paradigms were compared: 15 subjects each had been stimulated on both hands under the instruction to suppress the feeling of pain

    The gene coding for PGC-1α modifies age at onset in Huntington's Disease

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    Huntington's disease (HD) is one of the most common autosomal dominant inherited, neurodegenerative disorders. It is characterized by progressive motor, emotional and cognitive dysfunction. In addition metabolic abnormalities such as wasting and altered energy expenditure are increasingly recognized as clinical hallmarks of the disease. HD is caused by an unstable CAG repeat expansion in the HD gene (HTT), localized on chromosome 4p16.3. The number of CAG repeats in the HD gene is the main predictor of disease-onset, but the remaining variation is strongly heritable. Transcriptional dysregulation, mitochondrial dysfunction and enhanced oxidative stress have been implicated in the pathogenesis. Recent studies suggest that PGC-1α, a transcriptional master regulator of mitochondrial biogenesis and metabolism, is defective in HD. A genome wide search for modifier genes of HD age-of-onset had suggested linkage at chromosomal region 4p16-4p15, near the locus of PPARGC1A, the gene coding for PGC-1α. We now present data of 2-loci PPARGC1A block 2 haplotypes, showing an effect upon age-at-onset in 447 unrelated HD patients after statistical consideration of CAG repeat lengths in both HTT alleles. Block 1 haplotypes were not associated with the age-at-onset. Homozygosity for the 'protective' block 2 haplotype was associated with a significant delay in disease onset. To our knowledge this is the first study to show clinically relevant effects of the PGC-1α system on the course of Huntington's disease in humans

    Исследование свойств медных покрытий, полученных с помощью магнетрона с жидкофазной мишенью

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    В процессе работы проводились экспериментальные исследования структуры, шероховатости, электрического сопротивления и поверхности покрытий, полученных при разных условиях осаждения Осаждение медных покрытий из жидкой фазы с помощью МРС с испаряемой мишенью позволяет получить высокие скорости осаждения, низкое удельное электрическое сопротивление и хорошую адгезию пленок с подложкой по сравнению с осаждением из твердофазной МРС.In the course of the work, experimental studies of the structure, roughness, electrical resistance, and surface coatings obtained under different deposition conditions The deposition of copper coatings by means of an MSS with an evaporated target allows obtaining high deposition rates, low electrical resistivity, and good adhesion of the films to the substrate as compared to precipitation from the solid-state MSS

    Combining Literature Review With a Ground Truth Approach for Diagnosing Huntington's Disease Phenocopy.

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    One percent of patients with a Huntington's disease (HD) phenotype do not have the Huntington (HTT) gene mutation. These are known as HD phenocopies. Their diagnosis is still a challenge. Our objective is to provide a diagnostic approach to HD phenocopies based on medical expertise and a review of the literature. We employed two complementary approaches sequentially: a review of the literature and two surveys analyzing the daily clinical practice of physicians who are experts in movement disorders. The review of the literature was conducted from 1993 to 2020, by extracting articles about chorea or HD-like disorders from the database Pubmed, yielding 51 articles, and analyzing 20 articles in depth to establish the surveys. Twenty-eight physicians responded to the first survey exploring the red flags suggestive of specific disease entities. Thirty-three physicians completed the second survey which asked for the classification of paraclinical tests according to their diagnostic significance. The analysis of the results of the second survey used four different clustering algorithms and the density-based clustering algorithm DBSCAN to classify the paraclinical tests into 1st, 2nd, and 3rd-line recommendations. In addition, we included suggestions from members of the European Reference Network-Rare Neurological Diseases (ERN-RND Chorea & Huntington disease group). Finally, we propose guidance that integrate the detection of clinical red flags with a classification of paraclinical testing options to improve the diagnosis of HD phenocopies

    Plasmodynamic synthesis of product based on aluminum in the oxygen atmosphere of a reactor-chamber

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    In this paper, the possibility is shown to synthesize oxide aluminum using a high-speed electro discharge plasma jet. The synthesized products were characterized by X-Ray diffractometry and transmission electron microscopy
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