27 research outputs found

    Diagnostic value of blink reflex in multisystem atrophy, progressive supranuclear palsy and Parkinson disease

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    Abnormal blink reflex (BR) is a result of reticular brainstem pathways dysfunction and seems to be one of the features of brain degenerative disorders. The aim of the study was to estimate the diagnostic value of blink reflex in neurodegenerative diseases such as: multisystem atrophy (MSA), progressive supranuclear palsy (PSP) and Parkinson disease (PD). Material consisted of 99 patients with clinically probable MSA (51), PSP (28) and PD (20). MSA patients were divided into two subgroups, with dominant cerebellar (MSA-C) and parkinsonian signs (MSA-P). The mean age of patients was 64.9 years (47–79 years); males – 55.3%. Blink reflex was obtained in a typical way. Results The significant differences in mean values of blink reflex latencies between PD and other subgroups (MSA-P, MSA-C, PSP) were found, but all of them were in normal range. In individual patients with PD and PSP (50% and 18%, respectively) delayed R2 latencies were recorded. Conclusions The most frequently abnormal blink reflexes, comparing the MSA, PSP and PD groups, were present in PD patients. We postulate that this may be explained by pathological influence of nigrostriatal pathway on the circuit linking the basal ganglia, cerebellum and brainstem

    Hypoglossal nerve palsy as an isolated syndrome of internal carotid artery dissection: A review of the literature and a case report

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    A review of literature on the dissection of internal carotid artery was presented with apresentation of a rare case of patient with transient left hypoglossal nerve palsy caused bymechanic compression from intramural hematoma in higher extracranial portion of dissected carotid artery confirmed in MRI and CT scans. The clinical presentation and management are discussed

    Framework for Assessing the Feasibility of Carbon Dioxide Removal Options Within the National Context of Germany

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    Removal of carbon dioxide from the atmosphere will be required over the next decades to achieve the Paris Agreement goal of limiting global warming to well below 2°C aiming at not exceeding 1.5°C. Technological and ecosystem-based options are considered for generating negative emissions through carbon dioxide removal (CDR) and several nations have already included these in their Long-Term Low Greenhouse Gas Emission Development Strategies. However, strategies for development, implementation, and upscaling of CDR options often remain vague. Considering the scale at which CDR deployment is envisioned in emission pathways for limiting global warming to 1.5°C, significant environmental, social, and institutional implications are to be expected and need to be included in national feasibility assessments of CDR options. Following a multi-disciplinary and comprehensive approach, we created a framework that considers the environmental, technological, economic, social, institutional, and systemic implications of upscaling CDR options. We propose the framework as a tool to help guide decision-relevant feasibility assessments of CDR options, as well as identify challenges and opportunities within the national context. As such, the framework can serve as a means to inform and support decision makers and stakeholders in the iterative science-policy process of determining the role of CDR options in national strategies of achieving net-zero carbon emissions

    Quality Control of Motor Unit Number Index (MUNIX) Measurements in 6 Muscles in a Single-Subject “Round-Robin” Setup

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    Background Motor Unit Number Index (MUNIX) is a neurophysiological measure that provides an index of the number of lower motor neurons in a muscle. Its performance across centres in healthy subjects and patients with Amyotrophic Lateral Sclerosis (ALS) has been established, but inter-rater variability between multiple raters in one single subject has not been investigated. Objective To assess reliability in a set of 6 muscles in a single subject among 12 examiners (6 experienced with MUNIX, 6 less experienced) and to determine variables associated with variability of measurements. Methods Twelve raters applied MUNIX in six different muscles (abductor pollicis brevis (APB), abductor digiti minimi (ADM), biceps brachii (BB), tibialis anterior (TA), extensor dig. brevis (EDB), abductor hallucis (AH)) twice in one single volunteer on consecutive days. All raters visited at least one training course prior to measurements. Intra- and inter-rater variability as determined by the coefficient of variation (COV) between different raters and their levels of experience with MUNIX were compared. Results Mean intra-rater COV of MUNIX was 14.0% (±6.4) ranging from 5.8 (APB) to 30.3% (EDB). Mean inter-rater COV was 18.1 (±5.4) ranging from 8.0 (BB) to 31.7 (AH). No significant differences of variability between experienced and less experienced raters were detected. Conclusion We provide evidence that quality control for neurophysiological methods can be performed with similar standards as in laboratory medicine. Intra- and inter-rater variability of MUNIX is muscle-dependent and mainly below 20%. Experienced neurophysiologists can easily adopt MUNIX and adequate teaching ensures reliable utilization of this method

    Low Levels of DNA Polymerase Alpha Induce Mitotic and Meiotic Instability in the Ribosomal DNA Gene Cluster of Saccharomyces cerevisiae

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    The ribosomal DNA (rDNA) genes of Saccharomyces cerevisiae are located in a tandem array of about 150 repeats. Using a diploid with markers flanking and within the rDNA array, we showed that low levels of DNA polymerase alpha elevate recombination between both homologues and sister chromatids, about five-fold in mitotic cells and 30-fold in meiotic cells. This stimulation is independent of Fob1p, a protein required for the programmed replication fork block (RFB) in the rDNA. We observed that the fob1 mutation alone significantly increased meiotic, but not mitotic, rDNA recombination, suggesting a meiosis-specific role for this protein. We found that meiotic cells with low polymerase alpha had decreased Sir2p binding and increased Spo11p-catalyzed double-strand DNA breaks in the rDNA. Furthermore, meiotic crossover interference in the rDNA is absent. These results suggest that the hyper-Rec phenotypes resulting from low levels of DNA polymerase alpha in mitosis and meiosis reflect two fundamentally different mechanisms: the increased mitotic recombination is likely due to increased double-strand DNA breaks (DSBs) resulting from Fob1p-independent stalled replication forks, whereas the hyper-Rec meiotic phenotype results from increased levels of Spo11-catalyzed DSBs in the rDNA

    A Fine-Structure Map of Spontaneous Mitotic Crossovers in the Yeast Saccharomyces cerevisiae

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    Homologous recombination is an important mechanism for the repair of DNA damage in mitotically dividing cells. Mitotic crossovers between homologues with heterozygous alleles can produce two homozygous daughter cells (loss of heterozygosity), whereas crossovers between repeated genes on non-homologous chromosomes can result in translocations. Using a genetic system that allows selection of daughter cells that contain the reciprocal products of mitotic crossing over, we mapped crossovers and gene conversion events at a resolution of about 4 kb in a 120-kb region of chromosome V of Saccharomyces cerevisiae. The gene conversion tracts associated with mitotic crossovers are much longer (averaging about 12 kb) than the conversion tracts associated with meiotic recombination and are non-randomly distributed along the chromosome. In addition, about 40% of the conversion events have patterns of marker segregation that are most simply explained as reflecting the repair of a chromosome that was broken in G1 of the cell cycle

    Net‐Zero CO 2 Germany - A Retrospect From the Year 2050

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    Germany 2050: For the first time Germany reached a balance between its sources of anthropogenic CO2 to the atmosphere and newly created anthropogenic sinks. This backcasting study presents a fictional future in which this goal was achieved by avoiding (∼645 Mt CO2), reducing (∼50 Mt CO2) and removing (∼60 Mt CO2) carbon emissions. This meant substantial transformation of the energy system, increasing energy efficiency, sector coupling, and electrification, energy storage solutions including synthetic energy carriers, sector-specific solutions for industry, transport, and agriculture, as well as natural-sink enhancement and technological carbon dioxide options. All of the above was necessary to achieve a net-zero CO2 system for Germany by 2050

    Defective interaction between Pol2p and Dpb2p, subunits of DNA polymerase epsilon, contributes to a mutator phenotype in Saccharomyces cerevisiae.

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    Most of the prokaryotic and eukaryotic replicative polymerases are multi-subunit complexes. There are several examples indicating that noncatalytic subunits of DNA polymerases may function as fidelity factors during replication process. In this work, we have further investigated the role of Dpb2p, a noncatalytic subunit of DNA polymerase epsilon holoenzyme from Saccharomyces cerevisiae in controlling the level of spontaneous mutagenesis. The data presented indicate that impaired interaction between catalytic Pol2p subunit and Dpb2p is responsible for the observed mutator phenotype in S. cerevisiae strains carrying different mutated alleles of the DPB2 gene. We observed a significant correlation between the decreased level of interaction between different mutated forms of Dpb2p towards a wild-type form of Pol2p and the strength of mutator phenotype that they confer. We propose that structural integrity of the Pol epsilon holoenzyme is essential for genetic stability in S. cerevisiae cells
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