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15
result(s) for
"Merk, Johannes"
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Quantitative detection of TUSC3 promoter methylation -a potential biomarker for prognosis in lung cancer
by
Dietmaier, Wolfgang
,
Schulz, Christian
,
Woenckhaus, Matthias
in
Care and treatment
,
Deoxyribonucleic acid
,
Development and progression
2016
Aberrant promoter methylation of tumor relevant genes frequently occurs in early steps of carcinogenesis and during tumor progression. Epigenetic alterations could be used as potential biomarkers for early detection and for prediction of prognosis and therapy response in lung cancer. The present study quantitatively analyzed the methylation status of known and potential gatekeeper and tumor suppressor genes [O-6-methylguanine-DNA methyltransferase (MGMT), Ras association domain family member 1A (RASSF1A), Ras protein activator like 1 (RASAL1), programmed cell death 4 (PDCD4), metastasis suppressor 1 (MTSS1) and tumor suppressor candidate 3 (TUSC3)] in 42 lung cancers and in corresponding non-malignant bronchus and lung tissue using bisulfite-conversion independent methylation-quantification of endonuclease-resistant DNA (MethyQESD). Methylation status was associated with clinical and pathological parameters. No methylation was found in the promoter regions of PDCD4 and MTSS1 of either compartment. MGMT, RASSF1A and RASAL1 showed sporadic (up to 26.2%) promoter methylation. The promoter of TUSC3, however, was frequently methylated in the tumor (59.5%), benign bronchus (67.9%) and alveolar lung (31.0%) tissues from each tumor patient. The methylation status of TUSC3 was significantly associated with smaller tumor size (P=0.008) and a longer overall survival (P=0.013). Pooled blood DNA of healthy individuals did not show any methylation of either gene. Therefore, methylation of TUSC3 shows prognostic and pathobiological relevance in lung cancer. Furthermore, quantitative detection of TUSC3 promoter methylation appears to be a promising tool for early detection and prediction of prognosis in lung cancer. However, additional studies are required to confirm this finding.
Journal Article
Correlation of SHOX2 Gene Amplification and DNA Methylation in Lung Cancer Tumors
by
Rappold, Gudrun
,
Liebenberg, Volker
,
Merk, Johannes
in
Biomarkers
,
Biomarkers, Tumor - genetics
,
Biomarkers, Tumor - metabolism
2011
Background
DNA methylation in the
SHOX2
locus was previously used to reliably detect lung cancer in a group of critical controls, including 'cytologically negative' samples with no visible tumor cell content, at a high specificity based on the analysis of bronchial lavage samples. This study aimed to investigate, if the methylation correlates with
SHOX2
gene expression and/or copy number alterations. An amplification of the
SHOX2
gene locus together with the observed tumor-specific hypermethylation might explain the good performance of this marker in bronchial lavage samples.
Methods
SHOX2
expression, gene copy number and DNA methylation were determined in lung tumor tissues and matched morphologically normal adjacent tissues (NAT) from 55 lung cancer patients. Quantitative HeavyMethyl (HM) real-time PCR was used to detect
SHOX2
DNA methylation levels.
SHOX2
expression was assayed with quantitative real-time PCR, and copy numbers alterations were measured with conventional real-time PCR and array CGH.
Results
A hypermethylation of the
SHOX2
locus in tumor tissue as compared to the matched NAT from the same patient was detected in 96% of tumors from a group of 55 lung cancer patients. This correlated highly significantly with the frequent occurrence of copy number amplification (p < 0.0001), while the expression of the
SHOX2
gene showed no difference.
Conclusions
Frequent gene amplification correlated with hypermethylation of the
SHOX2
gene locus. This concerted effect qualifies
SHOX2
DNA methylation as a biomarker for lung cancer diagnosis, especially when sensitive detection is needed, i.e. in bronchial lavage or blood samples.
Journal Article
Effectiveness and cost-effectiveness of dynamic bracing versus standard care alone in patients suffering from osteoporotic vertebral compression fractures: protocol for a multicentre, two-armed, parallel-group randomised controlled trial with 12 months of follow-up
by
Willems, Paul C P H
,
Weber, Annemarijn
,
Huysmans, Stephanie M D
in
back pain
,
bone diseases
,
Cost analysis
2022
IntroductionPatients with osteoporosis may suffer from a fracture after minimal trauma. Osteoporotic vertebral compression fractures (OVCFs) are among the most common fractures, often leading to substantial pain. There is a need for evidence-based conservative treatment to aid in the management of OVCFs. The objective of this randomised controlled trial (RCT) is to evaluate the effectiveness and cost-effectiveness of dynamic bracing in addition to standard care for improving quality of life (QoL) in patients suffering from an OVCF.Methods and analysisNinety-eight postmenopausal women from two academic and four community hospitals with a recent symptomatic thoracolumbar OVCF will be randomised into either the standard care or dynamic bracing group. In the dynamic bracing group, the Spinova Osteo orthosis will be used in addition to standard care. Standard care comprises pain control with analgesics, physical therapy and osteoporosis medication. The primary outcome parameter is QoL 1 year after inclusion, as measured by the Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO-41). Secondary outcome parameters are pain, pain medication used, functional disability, sagittal spinal alignment, recurrence rate of OVCFs and physical activity in daily life. A trial-based economic evaluation consisting of both cost-effectiveness analysis and cost-utility analysis will be performed based on empirical data obtained in the RCT. A process evaluation will assess the feasibility of dynamic bracing. All outcomes will be assessed at baseline, 6 weeks, 3 months, 6 months, 9 months and 12 months.Ethics and disseminationEthical approval has been granted by the Medical Ethics Committee, University Hospital Maastricht and Maastricht University (METC azM/UM) (NL74552.068.20/METC 20-055). Patients will be included only after verification of eligibility and obtaining written informed consent. Results will be disseminated via the Dutch National Osteoporosis Patient Society and via publications and conferences.Trial registration numberNL8746.
Journal Article
Shared pathway-specific network mechanisms of dopamine and deep brain stimulation for the treatment of Parkinson’s disease
by
Faust, Katharina
,
Schneider, Gerd-Helge
,
Köhler, Richard M.
in
59/36
,
59/57
,
631/378/1689/1718
2025
Deep brain stimulation is a brain circuit intervention that can modulate distinct neural pathways for the alleviation of neurological symptoms in patients with brain disorders. In Parkinson’s disease, subthalamic deep brain stimulation clinically mimics the effect of dopaminergic drug treatment, but the shared pathway mechanisms on cortex – basal ganglia networks are unknown. To address this critical knowledge gap, we combined fully invasive neural multisite recordings in patients undergoing deep brain stimulation surgery with normative MRI-based whole-brain connectomics. Our findings demonstrate that dopamine and stimulation exert distinct mesoscale effects through modulation of local neural population activity. In contrast, at the macroscale, stimulation mimics dopamine in its suppression of excessive interregional network synchrony associated with indirect and hyperdirect cortex – basal ganglia pathways. Our results provide a better understanding of the circuit mechanisms of dopamine and deep brain stimulation, laying the foundation for advanced closed-loop neurostimulation therapies.
Dopaminergic medication and deep brain stimulation exert a shared therapeutic modulation of cortex-subthalamic nucleus network activity in Parkinson’s disease, through a suppression of high beta synchrony mediated by the hyperdirect pathway.
Journal Article
Tree islands enhance biodiversity and functioning in oil palm landscapes
2023
In the United Nations Decade on Ecosystem Restoration
1
, large knowledge gaps persist on how to increase biodiversity and ecosystem functioning in cash crop-dominated tropical landscapes
2
. Here, we present findings from a large-scale, 5-year ecosystem restoration experiment in an oil palm landscape enriched with 52 tree islands, encompassing assessments of ten indicators of biodiversity and 19 indicators of ecosystem functioning. Overall, indicators of biodiversity and ecosystem functioning, as well as multidiversity and ecosystem multifunctionality, were higher in tree islands compared to conventionally managed oil palm. Larger tree islands led to larger gains in multidiversity through changes in vegetation structure. Furthermore, tree enrichment did not decrease landscape-scale oil palm yield. Our results demonstrate that enriching oil palm-dominated landscapes with tree islands is a promising ecological restoration strategy, yet should not replace the protection of remaining forests.
A large-scale, five-year study in Indonesia finds that enriching oil palm-dominated landscapes with patches of trees bolsters biodiversity and ecosystem functioning without impairing oil palm yields but should not replace forest protection.
Journal Article
Methodological validation of Miro1 retention as a candidate Parkinson’s disease biomarker
by
Drwesh, Layla
,
Fitzgerald, Julia C.
,
Brockmann, Kathrin
in
631/378
,
692/53
,
Amyotrophic lateral sclerosis
2025
Mitochondrial markers help stratify Parkinson’s disease (PD) patients. We use high-throughput blotting to quantify Miro1, Mfn2, and VDAC levels in fibroblasts, blood cells, and iPSC-derived neurons. Miro1 is specifically retained in PD cells but degraded in healthy ones after mitochondrial depolarization. We correlate Miro1 retention scores with pathogenic mutations, genetic background, age, and clinical data. This scalable assay and quantifiable score for mitochondrial-PD support biomarker development and pharmacological screening.
Journal Article
A mouse model for embryonal tumors with multilayered rosettes uncovers the therapeutic potential of Sonic-hedgehog inhibitors
2017
Simultaneous activation of Wnt and Shh pathways in murine neural precursor cells results in the formation of embryonal tumors with multilayered rosettes (ETMR) that recapitulate the histological and molecular features of human tumors. This novel mouse model represents a platform for evaluating therapeutic approaches for this rare malignant pediatric brain tumor, and provides novel insights into the cell of origin and molecular mechanisms driving the disease.
Embryonal tumors with multilayered rosettes (ETMRs) have recently been described as a new entity of rare pediatric brain tumors with a fatal outcome. We show here that ETMRs are characterized by a parallel activation of Shh and Wnt signaling. Co-activation of these pathways in mouse neural precursors is sufficient to induce ETMR-like tumors
in vivo
that resemble their human counterparts on the basis of histology and global gene-expression analyses, and that point to apical radial glia cells as the possible tumor cell of origin. Overexpression of LIN28A, which is a hallmark of human ETMRs, augments Sonic-hedgehog (Shh) and Wnt signaling in these precursor cells through the downregulation of
let7
-miRNA, and LIN28A/
let7a
interaction with the Shh pathway was detected at the level of
Gli
mRNA. Finally, human ETMR cells that were transplanted into immunocompromised host mice were responsive to the SHH inhibitor arsenic trioxide (ATO). Our work provides a novel mouse model in which to study this tumor type, demonstrates the driving role of Wnt and Shh activation in the growth of ETMRs and proposes downstream inhibition of Shh signaling as a therapeutic option for patients with ETMRs.
Journal Article
Selenoprotein T Protects Endothelial Cells against Lipopolysaccharide-Induced Activation and Apoptosis
2021
Sepsis is an exaggerated immune response upon infection with lipopolysaccharide (LPS) as the main causative agent. LPS-induced activation and apoptosis of endothelial cells (EC) can lead to organ dysfunction and finally organ failure. We previously demonstrated that the first twenty amino acids of the Apurinic/Apyrimidinic Endodeoxyribonuclease 1 (APEX1) are sufficient to inhibit EC apoptosis. To identify genes whose regulation by LPS is affected by this N-terminal APEX1 peptide, EC were transduced with an expression vector for the APEX1 peptide or an empty control vector and treated with LPS. Following RNA deep sequencing, genes upregulated in LPS-treated EC expressing the APEX1 peptide were identified bioinformatically. Selected candidates were validated by semi-quantitative real time PCR, a promising one was Selenoprotein T (SELENOT). For functional analyses, an expression vector for SELENOT was generated. To study the effect of SELENOT expression on LPS-induced EC activation and apoptosis, the SELENOT vector was transfected in EC. Immunostaining showed that SELENOT was expressed and localized in the ER. EC transfected with the SELENOT plasmid showed no activation and reduced apoptosis induced by LPS. SELENOT as well as APEX1(1-20) can protect EC against activation and apoptosis and could provide new therapeutic approaches in the treatment of sepsis.
Journal Article
Welche Rolle spielen negative Emissionen für die zukünftige Klimapolitik?
2019
Eine rasche Reduktion der Treibhausgasemissionen ist essentiell, wenn ambitionierter Klimaschutz erreicht werden soll. Bei der Abschätzung der dafür notwendigen Anstrengungen und der Bewertung des zukünftigen Beitrags von Technologien, die es erlauben, der Atmosphäre CO2 zu entziehen (negative Emissionstechnologien, NETs), gehen die Meinungen und die Interpretationen des aktuellen Sonderberichts des Weltklimarats stark auseinander. Interpretationen, die sich auf eher große verbleibende CO2-Budgets stützen und damit gleichzeitig die Rolle von NETs für die Erreichung des Temperaturziels herunterspielen, führen nicht zu verantwortungsvollen oder realistischen Einschätzungen der zukünftigen (Forschungs-)Herausforderung: Wir müssen bereits jetzt die Wirksamkeit verschiedener NETs, ihre Grenzen und ihre Wechselwirkungen verstehen, wenn die international angestrebten CO2-Konzentrationspfade realistisch sein sollen. Eine verfrühte Festlegung auf bestimmte NETs sollte vermieden werden. Sobald die Technologien, die sich als effizient erweisen, ausgereift sind, sollte der Umfang ihres Einsatzes durch die Einbeziehung in CO2-Emissionshandelssysteme oder CO2-Emissionssteuerregime bestimmt werden.
Journal Article