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1.
Magn Reson Chem ; 61(12): 740-747, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37654196

RESUMO

Prostate cancer (PCa) is one of the most prevalent cancers in men worldwide. For its detection, serum prostate-specific antigen (PSA) screening is commonly used, despite its lack of specificity, high false positive rate, and inability to discriminate indolent from aggressive PCa. Following increases in serum PSA levels, clinicians often conduct prostate biopsies with or without advanced imaging. Nuclear magnetic resonance (NMR)-based metabolomics has proven to be promising for advancing early-detection and elucidation of disease progression, through the discovery and characterization of novel biomarkers. This retrospective study of urine-NMR samples, from prostate biopsy patients with and without PCa, identified several metabolites involved in energy metabolism, amino acid metabolism, and the hippuric acid pathway. Of note, lactate and hippurate-key metabolites involved in cellular proliferation and microbiome effects, respectively-were significantly altered, unveiling widespread metabolomic modifications associated with PCa development. These findings support urine metabolomics profiling as a promising strategy to identify new clinical biomarkers for PCa detection and diagnosis.


Assuntos
Antígeno Prostático Específico , Neoplasias da Próstata , Masculino , Humanos , Estudos Retrospectivos , Biomarcadores Tumorais , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Espectroscopia de Ressonância Magnética , Metabolômica/métodos
2.
Eur Respir J ; 62(2)2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37385655

RESUMO

BACKGROUND: Virus infections drive COPD exacerbations and progression. Antiviral immunity centres on the activation of virus-specific CD8+ T-cells by viral epitopes presented on major histocompatibility complex (MHC) class I molecules of infected cells. These epitopes are generated by the immunoproteasome, a specialised intracellular protein degradation machine, which is induced by antiviral cytokines in infected cells. METHODS: We analysed the effects of cigarette smoke on cytokine- and virus-mediated induction of the immunoproteasome in vitro, ex vivo and in vivo using RNA and Western blot analyses. CD8+ T-cell activation was determined in co-culture assays with cigarette smoke-exposed influenza A virus (IAV)-infected cells. Mass-spectrometry-based analysis of MHC class I-bound peptides uncovered the effects of cigarette smoke on inflammatory antigen presentation in lung cells. IAV-specific CD8+ T-cell numbers were determined in patients' peripheral blood using tetramer technology. RESULTS: Cigarette smoke impaired the induction of the immunoproteasome by cytokine signalling and viral infection in lung cells in vitro, ex vivo and in vivo. In addition, cigarette smoke altered the peptide repertoire of antigens presented on MHC class I molecules under inflammatory conditions. Importantly, MHC class I-mediated activation of IAV-specific CD8+ T-cells was dampened by cigarette smoke. COPD patients exhibited reduced numbers of circulating IAV-specific CD8+ T-cells compared to healthy controls and asthmatics. CONCLUSION: Our data indicate that cigarette smoke interferes with MHC class I antigen generation and presentation and thereby contributes to impaired activation of CD8+ T-cells upon virus infection. This adds important mechanistic insight on how cigarette smoke mediates increased susceptibility of smokers and COPD patients to viral infections.


Assuntos
Fumar Cigarros , Doença Pulmonar Obstrutiva Crônica , Humanos , Linfócitos T CD8-Positivos , Antivirais , Fumar Cigarros/efeitos adversos , Antígenos de Histocompatibilidade Classe I/metabolismo , Citocinas , Epitopos , Imunidade
3.
NMR Biomed ; 36(8): e4931, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36939957

RESUMO

Currently, many prostate cancer patients, detected through the prostate specific antigen test, harbor organ-confined indolent disease that cannot be differentiated from aggressive cancer according to clinically and pathologically known measures. Spermine has been considered as an endogenous inhibitor for prostate-confined cancer growth and its expression has shown correlation with prostate cancer growth rates. If established clinically, measurements of spermine bio-synthesis rates in prostates may predict prostate cancer growth and patient outcomes. Using rat models, we tested the feasibility of quantifying spermine bio-synthesis rates with 13 C NMR. Male Copenhagen rats (10 weeks, n = 6) were injected with uniformly 13 C-labeled L-ornithine HCl, and were sacrificed in pairs at 10, 30, and 60 min after injection. Another two rats were injected with saline and sacrificed at 30 min as controls. Prostates were harvested and extracted with perchloric acid and the neutralized solutions were examined by 13 C NMR at 600 MHz. 13 C NMR revealed measurable ornithine, as well as putrescine-spermidine-spermine syntheses in rat prostates, allowing polyamine bio-synthetic and ornithine bio-catabolic rates to be calculated. Our study demonstrated the feasibility of 13 C NMR for measuring bio-synthesis rates of ornithine to spermine enzymatic reactions in rat prostates. The current study established a foundation upon which future investigations of protocols that differentiate prostate cancer growth rates according to the measure of ornithine to spermine bio-synthetic rates may be developed.


Assuntos
Neoplasias da Próstata , Espermina , Masculino , Ratos , Animais , Humanos , Espermina/metabolismo , Próstata , Poliaminas/metabolismo , Ornitina/metabolismo , Ornitina/farmacologia
4.
Cancers (Basel) ; 14(9)2022 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-35565290

RESUMO

The aim of our study was to assess ex vivo HRMAS (high-resolution magic angle spinning) 1H NMR spectroscopy as a diagnostic tool for early PCa detection by testing whether metabolomic alterations in prostate biopsy samples can predict future PCa diagnosis. In a primary prospective study (04/2006-10/2018), fresh biopsy samples of 351 prostate biopsy patients were NMR spectroscopically analyzed (Bruker 14.1 Tesla, Billerica, MA, USA) and histopathologically evaluated. Three groups of 16 patients were compared: group 1 and 2 represented patients whose NMR scanned biopsy was histobenign, but patients in group 1 were diagnosed with cancer before the end of the study period, whereas patients in group 2 remained histobenign. Group 3 included cancer patients. Single-metabolite concentrations and metabolomic profiles were not only able to separate histobenign and malignant prostate tissue but also to differentiate between samples of histobenign patients who received a PCa diagnosis in the following years and those who remained histobenign. Our results support the hypothesis that metabolomic alterations significantly precede histologically visible changes, making metabolomic information highly beneficial for early PCa detection. Thanks to its predictive power, metabolomic information can be very valuable for the individualization of PCa active surveillance strategies.

5.
Metabolites ; 12(3)2022 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-35323696

RESUMO

Alzheimer's disease (AD) is a crippling condition that affects millions of elderly adults each year, yet there remains a serious need for improved methods of diagnosis. Metabolomic analysis has been proposed as a potential methodology to better investigate and understand the progression of this disease; however, studies of human brain tissue metabolomics are challenging, due to sample limitations and ethical considerations. Comprehensive comparisons of imaging measurements in animal models to identify similarities and differences between aging- and AD-associated metabolic changes should thus be tested and validated for future human non-invasive studies. In this paper, we present the results of our highresolution magic angle spinning (HRMAS) nuclear magnetic resonance (NMR) studies of AD and wild-type (WT) mouse models, based on animal age, brain regions, including cortex vs. hippocampus, and disease status. Our findings suggest the ability of HRMAS NMR to differentiate between AD and WT mice using brain metabolomics, which potentially can be implemented in in vivo evaluations.

6.
Nat Commun ; 13(1): 1544, 2022 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-35318328

RESUMO

Rhabdoid tumors (RT) are rare and highly aggressive pediatric neoplasms. Their epigenetically-driven intertumoral heterogeneity is well described; however, the cellular origin of RT remains an enigma. Here, we establish and characterize different genetically engineered mouse models driven under the control of distinct promoters and being active in early progenitor cell types with diverse embryonic onsets. From all models only Sox2-positive progenitor cells give rise to murine RT. Using single-cell analyses, we identify distinct cells of origin for the SHH and MYC subgroups of RT, rooting in early stages of embryogenesis. Intra- and extracranial MYC tumors harbor common genetic programs and potentially originate from fetal primordial germ cells (PGCs). Using PGC specific Smarcb1 knockout mouse models we validate that MYC RT originate from these progenitor cells. We uncover an epigenetic imbalance in MYC tumors compared to PGCs being sustained by epigenetically-driven subpopulations. Importantly, treatments with the DNA demethylating agent decitabine successfully impair tumor growth in vitro and in vivo. In summary, our work sheds light on the origin of RT and supports the clinical relevance of DNA methyltransferase inhibitors against this disease.


Assuntos
Tumor Rabdoide , Animais , Células Germinativas/patologia , Humanos , Camundongos , Tumor Rabdoide/genética , Tumor Rabdoide/patologia , Proteína SMARCB1/genética , Análise de Célula Única , Transcriptoma
7.
Clin Neuroradiol ; 32(1): 249-258, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34919158

RESUMO

PURPOSE: Recent research identified histone H3 K27M mutations to be associated with a dismal prognosis in pediatric diffuse midline glioma (pDMG); however, data on detailed MRI characteristics with respect to H3 K27 mutation status and molecular subgroups (H3.1 and H3.3 K27M mutations) are limited. METHODS: Standardized magnetic resonance imaging (MRI) parameters and epidemiologic data of 68 pDMG patients (age <18 years) were retrospectively reviewed and compared in a) H3 K27M mutant versus H3 K27 wildtype (WT) tumors and b) H3.1 versus H3.3 K27M mutant tumors. RESULTS: Intracranial gliomas (n = 58) showed heterogeneous phenotypes with isointense to hyperintense signal in T2-weighted images and frequent contrast enhancement. Hemorrhage and necrosis may be present. Comparing H3 K27M mutant to WT tumors, there were significant differences in the following parameters: i) tumor localization (p = 0.001), ii) T2 signal intensity (p = 0.021), and iii) T1 signal homogeneity (p = 0.02). No significant imaging differences were found in any parameter between H3.1 and H3.3 K27M mutant tumors; however, H3.1 mutant tumors occurred at a younger age (p = 0.004). Considering spinal gliomas (n = 10) there were no significant imaging differences between the analyzed molecular groups. CONCLUSION: With this study, we are the first to provide detailed MR imaging data on H3 K27M mutant pDMG with respect to molecular subgroup status in a large patient cohort. Our findings may support diagnosis and future targeted therapeutic trials of pDMG within the framework of the radiogenomics concept.


Assuntos
Neoplasias Encefálicas , Glioma , Adolescente , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Criança , Glioma/diagnóstico por imagem , Glioma/genética , Glioma/patologia , Histonas/genética , Humanos , Imageamento por Ressonância Magnética , Estudos Retrospectivos
8.
Proc Natl Acad Sci U S A ; 118(51)2021 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-34903652

RESUMO

The current high mortality of human lung cancer stems largely from the lack of feasible, early disease detection tools. An effective test with serum metabolomics predictive models able to suggest patients harboring disease could expedite triage patient to specialized imaging assessment. Here, using a training-validation-testing-cohort design, we establish our high-resolution magic angle spinning (HRMAS) magnetic resonance spectroscopy (MRS)-based metabolomics predictive models to indicate lung cancer presence and patient survival using serum samples collected prior to their disease diagnoses. Studied serum samples were collected from 79 patients before (within 5.0 y) and at lung cancer diagnosis. Disease predictive models were established by comparing serum metabolomic patterns between our training cohorts: patients with lung cancer at time of diagnosis, and matched healthy controls. These predictive models were then applied to evaluate serum samples of our validation and testing cohorts, all collected from patients before their lung cancer diagnosis. Our study found that the predictive model yielded values for prior-to-detection serum samples to be intermediate between values for patients at time of diagnosis and for healthy controls; these intermediate values significantly differed from both groups, with an F1 score = 0.628 for cancer prediction. Furthermore, values from metabolomics predictive model measured from prior-to-diagnosis sera could significantly predict 5-y survival for patients with localized disease.


Assuntos
Detecção Precoce de Câncer/métodos , Neoplasias Pulmonares/diagnóstico , Espectroscopia de Ressonância Magnética , Metabolômica , Idoso , Feminino , Humanos , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/metabolismo , Masculino , Redes e Vias Metabólicas , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reprodutibilidade dos Testes
9.
Sci Rep ; 9(1): 10319, 2019 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-31311965

RESUMO

Low-dose CT has shown promise in detecting early stage lung cancer. However, concerns about the adverse health effects of radiation and high cost prevent its use as a population-wide screening tool. Effective and feasible screening methods to triage suspicious patients to CT are needed. We investigated human lung cancer metabolomics from 93 paired tissue-serum samples with magnetic resonance spectroscopy and identified tissue and serum metabolomic markers that can differentiate cancer types and stages. Most interestingly, we identified serum metabolomic profiles that can predict patient overall survival for all cases (p = 0.0076), and more importantly for Stage I cases alone (n = 58, p = 0.0100), a prediction which is significant for treatment strategies but currently cannot be achieved by any clinical method. Prolonged survival is associated with relative overexpression of glutamine, valine, and glycine, and relative suppression of glutamate and lipids in serum.


Assuntos
Biomarcadores/sangue , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Metabolômica/métodos , Idoso , Feminino , Glutamina/sangue , Glicina/sangue , Humanos , Neoplasias Pulmonares/metabolismo , Espectroscopia de Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Análise de Sobrevida , Valina/sangue
10.
Nat Rev Urol ; 16(6): 339-362, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31092915

RESUMO

Urinary tests have been used as noninvasive, cost-effective tools for screening, diagnosis and monitoring of diseases since ancient times. As we progress through the 21st century, modern analytical platforms have enabled effective measurement of metabolites, with promising results for both a deeper understanding of cancer pathophysiology and, ultimately, clinical translation. The first study to measure metabolomic urinary cancer biomarkers using NMR and mass spectrometry (MS) was published in 2006 and, since then, these techniques have been used to detect cancers of the urological system (kidney, prostate and bladder) and nonurological tumours including those of the breast, ovary, lung, liver, gastrointestinal tract, pancreas, bone and blood. This growing field warrants an assessment of the current status of research developments and recommendations to help systematize future research.


Assuntos
Biomarcadores Tumorais/urina , Metaboloma , Neoplasias/urina , Detecção Precoce de Câncer/métodos , Humanos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/urina , Masculino , Metabolômica/métodos , Neoplasias/diagnóstico , Neoplasias/metabolismo , Guias de Prática Clínica como Assunto , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/urina , Neoplasias Urológicas/diagnóstico , Neoplasias Urológicas/metabolismo , Neoplasias Urológicas/urina
11.
Clin Neuroradiol ; 29(4): 595-604, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30027327

RESUMO

PURPOSE: Epigenetic profiling has recently identified clinically and molecularly distinct subgroups of ependymoma. The 2016 World Health Organization (WHO) classification recognized supratentorial ependymomas (ST-EPN) with REL-associated protein/p65 (RELA) fusion as a clinicopathological entity. These tumors represent 70% of pediatric ST-EPN characterized by recurrent C11orf95-RELA fusion transcripts, which lead to pathological activation of the nuclear factor 'kappa-light-chain-enhancer' of activated B-cells (NF-κB) signaling pathway. Cyclin-dependent kinase inhibitor 2A (CDKN2A) inactivation has also been reported to correlate with poor prognosis. Here, we systematically describe magnetic resonance imaging (MRI) characteristics of RELA-fused ST-EPN, with respect to CDKN2A deletion status. METHODS: Our cohort of patients with ST-EPN (n = 57) was obtained from the database of the German Brain Tumor Reference Center of the German Society for Neuropathology and Neuroanatomy (DGNN), and tumors were diagnosed according to the 2016 WHO classification. Molecular characterization identified 47 RELA-fused tumors. We analyzed the preoperative MRI according to standardized criteria, and comparison was performed between CDKN2A altered (n = 21) and CDKN2A wild type (n = 26) tumors. RESULTS: The RELA-fused ST-EPN showed a spectrum of predominantly hemispheric tumors with cysts and necrosis. Statistical analysis on CDKN2A status revealed significant differences in terms of younger manifestation age (p =0.002) and more intratumoral hemorrhage in T2-weighted imaging (T2WI) (p =0.010) in wild type tumors; however, the location was not a parameter for differentiation. CONCLUSION: This study first provides comprehensive MRI data for RELA-fused ST-EPN as a distinct entity, with further interest on CDKN2A genomic status. Patient stratification by morphological MRI alone seems difficult at present. The results may support ongoing research in ST-EPN within the framework of the radiogenomics concept.


Assuntos
Ependimoma/diagnóstico por imagem , Neoplasias Supratentoriais/diagnóstico por imagem , Fator de Transcrição RelA/metabolismo , Adolescente , Criança , Pré-Escolar , Bases de Dados Factuais , Ependimoma/genética , Ependimoma/metabolismo , Ependimoma/patologia , Feminino , Deleção de Genes , Genes p16 , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Gradação de Tumores , Proteínas de Fusão Oncogênica/metabolismo , Fenótipo , Neoplasias Supratentoriais/genética , Neoplasias Supratentoriais/metabolismo , Neoplasias Supratentoriais/patologia
12.
Eur Arch Psychiatry Clin Neurosci ; 269(5): 587-598, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30288559

RESUMO

Given the particular relevance of arousal and alerting in panic disorder (PD), here the alerting network was investigated (1) contrasting patients with PD and healthy controls, (2) as a function of anxiety sensitivity constituting a dimensional measure of panic-related anxiety, and (3) as a possible correlate of treatment response. Using functional magnetic resonance imaging (fMRI), 45 out-patients with PD (f = 34) and 51 matched healthy controls were investigated for brain activation patterns and effective connectivity (Dynamic Causal Modeling, DCM) while performing the Attention Network Task (ANT). Anxiety sensitivity was ascertained by the Anxiety Sensitivity Index (ASI). Forty patients and 48 controls were re-scanned after a 6 weeks cognitive-behavioral treatment (CBT) or an equivalent waiting time, respectively. In the alerting condition, patients showed decreased activation in fronto-parietal pathways including the middle frontal gyrus and the superior parietal lobule (MFG, SPL). In addition, ASI scores were negatively correlated with connectivity emerging from the SPL, the SFB and the LC and going to the MFG in patients but not in healthy controls. CBT resulted in an increase in middle frontal and parietal activation along with increased connectivity going from the MFG to the SPL. This change in connectivity was positively correlated with reduction in ASI scores. There were no changes in controls. The present findings point to a pathological disintegration of the MFG in a fronto-parietal pathway in the alerting network in PD which was observed to be reversible by a successful CBT intervention.


Assuntos
Atenção/fisiologia , Encéfalo/diagnóstico por imagem , Rede Nervosa/diagnóstico por imagem , Transtorno de Pânico/terapia , Adulto , Encéfalo/fisiopatologia , Terapia Cognitivo-Comportamental , Feminino , Neuroimagem Funcional , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Rede Nervosa/fisiopatologia , Transtorno de Pânico/diagnóstico por imagem , Transtorno de Pânico/fisiopatologia , Adulto Jovem
13.
Neuro Oncol ; 20(12): 1672-1679, 2018 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-30010851

RESUMO

Background: Recently, 3 molecular subgroups of atypical teratoid/rhabdoid tumor (ATRT) were identified, but little is known of their clinical and magnetic resonance imaging (MRI) characteristics. Methods: A total of 43 patients with known molecular subgroup status (ATRT-sonic hedgehog [SHH], n = 17; ATRT-tyrosine [TYR], n = 16; ATRT-myelocytomatosis oncogene [MYC], n = 10) were retrieved from the EU-RHAB Registry and analyzed for clinical and MRI features. Results: On MRI review, differences in preferential tumor location were confirmed, with ATRT-TYR being predominantly located infratentorially (P < 0.05). Peritumoral edema was more pronounced in ATRT-MYC compared with ATRT-SHH (P < 0.05) and ATRT-TYR (P < 0.05). Conversely, peripheral tumor cysts were found more frequently in ATRT-SHH (71%) and ATRT-TYR (94%) compared with ATRT-MYC (40%, P < 0.05). Contrast enhancement was absent in 29% of ATRT-SHH (0% of ATRT-TYR; 10% of ATRT-MYC; P < 0.05), and there was a trend toward strong contrast enhancement in ATRT-TYR and ATRT-MYC. We found the characteristic (bandlike) enhancement in 28% of ATRT as well as restricted diffusion in the majority of tumors. A midline/off-midline location in the posterior fossa was also not subgroup specific. Visible meningeal spread (M2) at diagnosis was rare throughout all subgroups. Conclusion: These exploratory findings suggest that MRI features vary across the 3 molecular subgroups of ATRT. Within future prospective trials, MRI may aid diagnosis and treatment stratification.


Assuntos
Proteínas Hedgehog/genética , Imageamento por Ressonância Magnética/métodos , Proteínas Proto-Oncogênicas c-myc/genética , Tumor Rabdoide/diagnóstico , Teratoma/diagnóstico , Tirosina/metabolismo , Biomarcadores Tumorais/análise , Pré-Escolar , Diagnóstico Diferencial , Feminino , Seguimentos , Humanos , Masculino , Prognóstico , Estudos Retrospectivos , Tumor Rabdoide/genética , Tumor Rabdoide/metabolismo , Teratoma/genética , Teratoma/metabolismo
14.
Soft Matter ; 14(33): 6809-6821, 2018 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-30043822

RESUMO

Soft elastic composite materials containing particulate rigid inclusions in a soft elastic matrix are candidates for developing soft actuators or tunable damping devices. The possibility to reversibly drive the rigid inclusions within such a composite together to a close-to-touching state by an external stimulus would offer important benefits. Then, a significant tuning of the mechanical properties could be achieved due to the resulting mechanical hardening. For a long time, it has been argued whether a virtual touching of the embedded magnetic particles with subsequent detachment can actually be observed in real materials, and if so, whether the process is reversible. Here, we present experimental results that demonstrate this phenomenon in reality. Our system consists of two paramagnetic nickel particles embedded at finite initial distance in a soft elastic polymeric gel matrix. Magnetization in an external magnetic field tunes the magnetic attraction between the particles and drives the process. We quantify our experimental results by different theoretical tools, i.e., explicit analytical calculations in the framework of linear elasticity theory, a projection onto simplified dipole-spring models, as well as detailed finite-element simulations. From these different approaches, we conclude that in our case the cycle of virtual touching and detachment shows hysteretic behavior due to the mutual magnetization between the paramagnetic particles. Our results are important for the design and construction of reversibly tunable mechanical damping devices. Moreover, our projection on dipole-spring models allows the formal connection of our description to various related systems, e.g., magnetosome filaments in magnetotactic bacteria.

15.
J Acoust Soc Am ; 142(3): 1634, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28964092

RESUMO

This article deals with the assessment and prediction of the reproduction quality when binaurally auralizing spherical microphone array data for room simulation applications. The auralization is perceptually assessed in a listening experiment using the two attributes, apparent source width (ASW) and listener envelopment (LEV), for spatial quality description, whereas the technical analysis employs a psychoacoustically motivated model for room acoustical perception (RAP) which is specifically designed to estimate ASW and LEV. Both analyses focus on the array configuration in terms of varying modal resolutions and its influence on the spatial reproduction quality. The auralizations comprise three simulated environments, i.e., free-field sound fields as well as a dry and a reverberant room. Ten different audio signals are used as test material. Perceptual results show that the array configuration strongly influences the perception of ASW and LEV which also depends on the reflection properties of the simulated room. The ASW and LEV predictions by the RAP model correlate well with the results from the listening experiment.


Assuntos
Acústica , Percepção Auditiva , Música , Percepção Espacial , Adulto , Arquitetura de Instituições de Saúde , Feminino , Voluntários Saudáveis , Humanos , Masculino , Canto , Localização de Som
16.
NMR Biomed ; 30(11)2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28915318

RESUMO

High-resolution magic angle spinning (HRMAS) MRS is a powerful method for gaining insight into the physiological and pathological processes of cellular metabolism. Given its ability to obtain high-resolution spectra of non-liquid biological samples, while preserving tissue architecture for subsequent histopathological analysis, the technique has become invaluable for biochemical and biomedical studies. Using HRMAS MRS, alterations in measured metabolites, metabolic ratios, and metabolomic profiles present the possibility to improve identification and prognostication of various diseases and decipher the metabolomic impact of drug therapies. In this review, we evaluate HRMAS MRS results on human tissue specimens from malignancies and non-localized diseases reported in the literature since the inception of the technique in 1996. We present the diverse applications of the technique in understanding pathological processes of different anatomical origins, correlations with in vivo imaging, effectiveness of therapies, and progress in the HRMAS methodology.


Assuntos
Espectroscopia de Ressonância Magnética/métodos , Encéfalo/metabolismo , Neoplasias Encefálicas/metabolismo , Cartilagem/metabolismo , Feminino , Neoplasias Gastrointestinais/metabolismo , Neoplasias dos Genitais Femininos/metabolismo , Neoplasias dos Genitais Femininos/patologia , Humanos , Neoplasias Pulmonares/metabolismo , Masculino , Metabolômica , Neoplasias da Próstata/metabolismo
17.
Nat Med ; 23(10): 1191-1202, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28892064

RESUMO

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.


Assuntos
Antineoplásicos/farmacologia , Arsenicais/farmacologia , Neoplasias Encefálicas/genética , Proteínas Hedgehog/genética , Neoplasias Embrionárias de Células Germinativas/genética , Óxidos/farmacologia , Via de Sinalização Wnt/genética , Animais , Trióxido de Arsênio , Western Blotting , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral , Modelos Animais de Doenças , Regulação para Baixo , Perfilação da Expressão Gênica , Proteínas Hedgehog/antagonistas & inibidores , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Transgênicos , MicroRNAs/genética , Neoplasias Embrionárias de Células Germinativas/metabolismo , Proteínas de Ligação a RNA/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Ensaios Antitumorais Modelo de Xenoenxerto , Proteína GLI1 em Dedos de Zinco/genética
18.
Lab Chip ; 16(20): 3977-3989, 2016 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-27713982

RESUMO

Smart hydrogels are useful elements in microfluidic systems because they respond to environmental stimuli and are capable of storing reagents. We present here a concept of using hydrogels (poly(N-isopropylacrylamide)) as an interface between continuous and discontinuous microfluidics. Their swelling and shrinking capabilities allow them to act as storage elements for reagents absorbed in the swelling process. When the swollen hydrogel collapses in an oil-filled channel, the incorporated water and molecules are expelled from the hydrogel and form a water reservoir. Water-in-oil droplets can be released from the reservoir generating different sized droplets depending on the flow regime at various oil flow rates (dispensing functionality). Different hydrogel sizes and microfluidic structures are discussed in terms of their storage and droplet formation capabilities. The time behaviour of the hydrogel element is investigated by dynamic swelling experiments and computational fluid dynamics simulations. By precise temperature control, the device acts as an active droplet generator and converts continuous to discontinuous flows.

19.
Eur Neuropsychopharmacol ; 26(8): 1274-85, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27262510

RESUMO

Facilitated processing of interoceptive and exteroceptive information in the salience network is suggested to promote the development of anxiety and anxiety disorders. Here, it was investigated whether the adenosine 2 A receptor gene (ADORA2A) 1976T/C (rs5751876) variant - previously associated with anxiety disorders and anxiety-related phenotypes as well as general attentional efficiency -was involved in the regulation of this network. In detail, fMRI recordings of 65 healthy participants (female=35) were analyzed regarding ADORA2A genotype effects on brain connectivity related to (1) interoceptive processing in terms of functional connectivity resting-state fMRI, and (2) exteroceptive processing using dynamic causal modeling in task-based fMRI. In a subsample, cardiac interoceptive accuracy was furthermore measured via the Mental Tracking Task. ADORA2A genotype was found to modulate a fronto-insular network at rest (interoceptive processing) and while performing an executive control task (exteroceptive processing). Across both modalities, the ADORA2A TT risk genotype was associated with increased connectivity between the insula and the prefrontal cortex. The strength in connectivity correlated with interoceptive accuracy. It is concluded that alterations in fronto-insular connectivity are modulated by both the adenosinergic system and interoceptive accuracy. Thus, fronto-insular connectivity in synopsis with ADORA2A genotypic information could serve as combined biomarkers for personalized treatment approaches in anxiety disorders targeting exteroceptive and interoceptive dysfunction.


Assuntos
Córtex Cerebral/fisiologia , Função Executiva , Lobo Frontal/fisiologia , Modelos Neurológicos , Rede Nervosa/fisiologia , Polimorfismo de Nucleotídeo Único , Receptor A2A de Adenosina/genética , Adulto , Ansiedade/genética , Ansiedade/fisiopatologia , Transtornos de Ansiedade/genética , Transtornos de Ansiedade/fisiopatologia , Córtex Cerebral/fisiopatologia , Feminino , Lobo Frontal/fisiopatologia , Estudos de Associação Genética , Predisposição Genética para Doença , Alemanha , Humanos , Imageamento por Ressonância Magnética , Masculino , Rede Nervosa/fisiopatologia , Neuroimagem , Estudo de Prova de Conceito , Análise e Desempenho de Tarefas , Adulto Jovem
20.
Soft Matter ; 12(1): 228-37, 2016 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-26463270

RESUMO

We study the magneto-elastic coupling behavior of paramagnetic chains in soft polymer gels exposed to external magnetic fields. To this end, a laser scanning confocal microscope is used to observe the morphology of the paramagnetic chains together with the deformation field of the surrounding gel network. The paramagnetic chains in soft polymer gels show rich morphological shape changes under oblique magnetic fields, in particular a pronounced buckling deformation. The details of the resulting morphological shapes depend on the length of the chain, the strength of the external magnetic field, and the modulus of the gel. Based on the observation that the magnetic chains are strongly coupled to the surrounding polymer network, a simplified model is developed to describe their buckling behavior. A coarse-grained molecular dynamics simulation model featuring an increased matrix stiffness on the surfaces of the particles leads to morphologies in agreement with the experimentally observed buckling effects.

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