Publications by authors named "Giehl K"

Article Synopsis
  • This study investigated the relationship between tau pathology in specific brain regions and apraxia symptoms in Alzheimer's disease (AD) patients, using PET imaging to assess tau deposition.
  • Researchers hypothesized that certain areas with tau buildup would correlate with the severity of apraxia, a common cognitive dysfunction in AD.
  • Findings revealed significant correlations between tau aggregation in specific praxis-related brain regions and apraxia severity, while no connections were found in primary motor cortex or subcortical regions.
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The relative inability to produce effortful movements is the most specific motor sign of Parkinson's disease, which is primarily characterized by loss of dopaminergic terminals in the putamen. The motor motivation hypothesis suggests that this motor deficit may not reflect a deficiency in motor control per se, but a deficiency in cost-benefit considerations for motor effort. For the first time, we investigated the quantitative effect of dopamine depletion on the motivation of motor effort in Parkinson's disease.

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The sharing of human neuroimaging data has great potential to accelerate the development of imaging biomarkers in neurological and psychiatric disorders; however, major obstacles remain in terms of how and why to share data in the Open Science context. In this Health Policy by the European Cluster for Imaging Biomarkers, we outline the current main opportunities and challenges based on the results of an online survey disseminated among senior scientists in the field. Although the scientific community fully recognises the importance of data sharing, technical, legal, and motivational aspects often prevent active adoption.

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Inborn errors of immunity (IEI) can affect different parts of the immune system and manifest especially through pathological infection susceptibility and immune dysregulation. Cutaneous manifestations of IEI can hint at the underlying immunodeficiency and the tendency for infection and inflammation. These manifestations can present as recurring eczema, erythema, abscesses, and hair loss with poor response to therapy.

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Background: Keratinopathic ichthyoses are a group of hereditary skin disorders caused by pathogenic variants in keratin genes such as KRT1, KRT2 and KRT10, resulting in conditions such as epidermolytic ichthyosis (EI), autosomal-recessive EI, superficial EI and epidermal nevus. Case reports highlight the diversity of clinical manifestations, but only limited information exists regarding the quality of life and burden of disease.

Objectives: The objective of this study was to assess the clinical spectrum, genotype-phenotype correlations and burden of disease in patients with epidermolytic ichthyosis in Germany.

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Objectives: Apraxia is a core feature of Alzheimer's disease, but the pathomechanism of this characteristic symptom is not well understood. Here, we systematically investigated apraxia profiles in a well-defined group of patients with Alzheimer's disease (AD; N=32) who additionally underwent PET imaging with the second-generation tau PET tracer [18F]PI-2620. We hypothesized that specific patterns of tau pathology might be related to apraxic deficits.

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Objectives: Higher-educated patients with Alzheimer disease (AD) can harbor greater neuropathologic burden than those with less education despite similar symptom severity. In this study, we assessed whether this observation is also present in potential preclinical AD stages, namely in individuals with subjective cognitive decline and clinical features increasing AD likelihood (SCD+).

Methods: Amyloid-PET information ([F]Flutemetamol or [F]Florbetaben) of individuals with SCD+, mild cognitive impairment (MCI), and AD were retrieved from the AMYPAD-DPMS cohort, a multicenter randomized controlled study.

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K-Ras is the most frequently mutated Ras variant in pancreatic, colon and non-small cell lung adenocarcinoma. Activating mutations in K-Ras result in increased amounts of active Ras-GTP and subsequently a hyperactivation of effector proteins and downstream signaling pathways. Here, we demonstrate that oncogenic K-Ras(V12) regulates tumor cell migration by activating the phosphatidylinositol 3-kinases (PI3-K)/Akt pathway and induces the expression of E-cadherin and neural cell adhesion molecule (NCAM) by upregulation of Akt3.

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Patients with Parkinson's disease are highly vulnerable for cognitive decline. Thus, early intervention by means of working memory training (WMT) may be effective for the preservation of cognition. However, the influence of structural brain properties, i.

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Stereotypical isocortical tau protein pathology along the Braak stages has been described as an instigator of neurodegeneration in Alzheimer's disease (AD). Less is known about tau pathology in motor regions, although higher-order motor deficits such as praxis dysfunction are part of the clinical description. Here, we examined how tau pathology in cytoarchitectonically mapped regions of the primary and higher-order motor network in comparison to primary visual and sensory regions varies across the clinical spectrum of AD.

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Background: Short anagen hair (SAH) is a rare paediatric hair disorder characterized by a short anagen phase, an inability to grow long scalp hair and a negative psychological impact. The genetic basis of SAH is currently unknown.

Objectives: To perform molecular genetic investigations in 48 individuals with a clinical phenotype suggestive of SAH to identify, if any, the genetic basis of this condition.

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Background: A critical challenge for Huntington's disease (HD) clinical trials in disease modification is the definition of endpoints that can capture change when clinical signs are subtle/non-existent. Reliable biomarkers are therefore urgently needed to facilitate drug development by allowing the enrichment of clinical trial populations and providing measures of benefit that can support the establishment of efficacy.

Methods: By systematically examining the published literature on HD neuroimaging biomarker studies, we sought to advance knowledge to guide the validation of neuroimaging biomarkers.

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Article Synopsis
  • Autosomal recessive congenital ichthyosis (ARCI) is a skin disorder characterized by abnormal scaling and has three main forms: lamellar ichthyosis, congenital ichthyosiform erythroderma, and harlequin ichthyosis.
  • The condition is caused by mutations in several genes, with the most severe form (harlequin ichthyosis) primarily linked to specific mutations in one gene, which can also lead to the other two forms.
  • A study involving 64 patients identified 34 novel mutations, expanding the known mutations associated with this condition and showing a connection between the type of mutation and the severity of the skin condition.
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The primary cause for cancer-related death is metastasis, and although this phenomenon is the hallmark of cancer, it remains poorly understood. Since studies on the underlying mechanisms are still demanding by experimental means prognostic tools based on computer models can be of great value, not only for elucidating metastasis formation but also for assessing the prospective benefits as well as risks of a therapy for patients with advanced cancer. Here, we present an agent-based model (ABM), describing the complete process of platelet-assisted extravasation of circulating tumor cells (CTCs) from the chemoattraction of blood platelets by the CTCs up to the embedding of the CTCs in the epithelial tissue by computational means.

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Article Synopsis
  • Epidermolysis bullosa (EB) is a rare genetic skin disorder causing blisters to form on the skin and mucous membranes, with varying severity among patients.
  • A study conducted in Germany found an EB incidence of 45 cases per million live births, with higher rates for junctional EB compared to other countries, possibly due to better early genetic diagnosis.
  • With estimates of around 2000 EB patients in Germany, the findings aim to influence healthcare policies, drug development strategies, and support patient advocacy efforts for improved quality of life.
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Background: Working memory (WM) training (WMT) is a popular intervention approach against cognitive decline in patients with Parkinson's disease (PD). However, heterogeneity in WM responsiveness suggests that WMT may not be equally efficient for all patients.

Objective: The present study aims to evaluate a multivariate model to predict post-intervention verbal WM in patients with PD using a supervised machine learning approach.

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