302 stran : grafy, tabulky ; 23 cm
- MeSH
- Cell Tracking methods MeSH
- Fluorine chemistry MeSH
- Fluorocarbons MeSH
- Contrast Media MeSH
- Cell Movement MeSH
- Fluorine-19 Magnetic Resonance Imaging MeSH
- Conspectus
- Patologie. Klinická medicína
- NML Fields
- radiologie, nukleární medicína a zobrazovací metody
- NML Publication type
- kolektivní monografie
The formation of memories is a complex, multi-scale phenomenon, especially when it involves integration of information from various brain systems. We have investigated the differences between a novel and consolidated association of spatial cues and amphetamine administration, using an in situ hybridisation method to track the short-term dynamics during the recall testing. We have found that remote recall group involves smaller, but more consolidated groups of neurons, which is consistent with their specialisation. By employing machine learning analysis, we have shown this pattern is especially pronounced in the VTA; furthermore, we also uncovered significant activity patterns in retrosplenial and prefrontal cortices, as well as in the DG and CA3 subfields of the hippocampus. The behavioural propensity towards the associated localisation appears to be driven by the nucleus accumbens, however, further modulated by a trio of the amygdala, VTA and hippocampus, as the trained association is confronted with test experience. Moreover, chemogenetic analysis revealed central amygdala as critical for linking appetitive emotional states with spatial contexts. These results show that memory mechanisms must be modelled considering individual differences in motivation, as well as covering dynamics of the process.
- MeSH
- Amphetamine pharmacology MeSH
- Amygdala physiology MeSH
- Hippocampus * physiology MeSH
- Memory Consolidation * physiology MeSH
- Rats MeSH
- Brain physiology MeSH
- Neurons physiology metabolism MeSH
- Nucleus Accumbens * physiology MeSH
- Reward * MeSH
- Memory physiology MeSH
- Cues MeSH
- Prefrontal Cortex physiology MeSH
- Mental Recall * physiology MeSH
- Machine Learning MeSH
- Ventral Tegmental Area * physiology MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
BACKGROUND: Diagnosing primary or secondary CNS lymphoma (CNSL) is a clinical challenge due to the limitations of standard biopsy and imaging procedures despite established guidelines. Therefore, accurate biomarkers and analytical methods that are convenient for practical routine use are needed to diagnose and manage these aggressive lymphomas effectively. We evaluated the utility of minimally invasive circulating tumor DNA (ctDNA) detection in a prospective real-world scenario, moving this approach closer to clinical practice. METHODS: A total of 164 plasma, cerebrospinal fluid (CSF), and tumor samples from 56 CNSL patients were collected to analyze tumor DNA by the diagnostic next-generation sequencing (NGS) panel LYNX, enabling simultaneous analysis of gene variants, chromosomal aberrations, and antigen receptor rearrangements in targeted regions. RESULTS: The well-known genetic heterogeneity of CNSL was refined with integrative molecular data, showing the most frequent MYD88, PIM1, and KMT2D mutations and a broad spectrum of chromosomal aberrations, reflecting high genomic complexity. The multi-target approach achieved a substantially higher detection rate of CNS infiltration (90%) than tracking a single variant in gene MYD88 (46%). CSF clearly surpasses plasma if applying a routine (non-ultrasensitive) NGS approach and allows for more reliable evidence of CNS involvement than conventional flow cytometry (91% vs. 21%, p < 0.001). Parallel analysis of tumor DNA in both cell-free and cellular DNA from CSF makes the probability of primary or secondary CNS malignancy detection even higher. CONCLUSIONS: Our prospective, tissue-agnostic approach highlights the feasibility of ctDNA sequencing by a commonplace and affordable method, offering higher sensitivity to detect CNS infiltration with lymphoma than standard cell-analyzing techniques. We accentuate the benefit of a multi-target NGS approach and adequate CSF sampling to obtain satisfactory diagnostic yield. Less invasive liquid biopsy testing by comprehensive NGS complements standard procedures in the diagnostics and management of CNSL patients, especially when encountering limitations.
- Publication type
- Journal Article MeSH
PURPOSE: Extranodal extension (ENE) increases the risk of recurrence and death in head and neck squamous cell carcinoma (HNSCC) patients and is an indication for treatment escalation. Histopathology forms the mainstay of diagnosing ENE. There is substantial variation in the diagnosis of ENE and related terminology. Harmonising the diagnostic criteria for ENE was identified as a priority by the Head and Neck Consensus Language for Ease of Reproducibility (HN CLEAR) Steering Committee and its global stakeholders. METHODS: An international working group including 16 head and neck pathologists from eight countries across five continents evaluated whole slide images of haematoxylin and eosin-stained sections depicting potential diagnostic problems through nine virtual meetings to develop consensus guidelines. RESULTS: ENE should be diagnosed only when viable carcinoma extends through the primary lymph node (LN) capsule and directly interacts with the extranodal host environment with or without desmoplastic stromal response. Identifying the original LN capsule and reconstruction of its contour can assist in the detection and assessment of ENE. The term matting is recommended for confluence of two or more nodes due to histologically identifiable tumour extending from one LN to another. Matting constitutes major form of ENE. On the other hand, the terms fusion/adhesion/confluence/conglomeration and other synonyms of adhesion should be limited to confluence due to fibrosis or inflammation without histologically identifiable tumour between involved lymph nodes. Tumour extension along narrow needle tracks or spillage of cyst contents following an FNA do not constitute ENE. CONCLUSIONS: The consensus recommendations encompassing the definition of ENE, macroscopic and histologic examination of lymph nodes (LN) and practical guidelines for handling challenging cases are provided.
Fluorescent biosensors offer a powerful tool for tracking and quantifying protein activity in living systems with high temporospatial resolution. However, the expression of genetically encoded fluorescent proteins can interfere with endogenous signaling pathways, potentially leading to developmental and physiological abnormalities. The EKAREV-NLS mouse model, which carries a FRET-based biosensor for monitoring extracellular signal-regulated kinase (ERK) activity, has been widely utilized both in vivo and in vitro across various cell types and organs. In this study, we report a significant defect in mammary epithelial development in EKAREV-NLS C57BL/6J female mice. Our findings reveal that these mice exhibit severely impaired mammary epithelial outgrowth, linked to systemic defects including disrupted estrous cycling, impaired ovarian follicle maturation, anovulation, and reduced reproductive fitness. Notably, estrogen supplementation was sufficient to enhance mammary epithelial growth in the EKAREV-NLS C57BL/6J females. Furthermore, outcrossing to the ICR genetic background fully restored normal mammary epithelial outgrowth, indicating that the observed phenotype is dependent on genetic background. We also confirmed the functional performance of the biosensor in hormone-supplemented and outcrossed tissues through time-lapse imaging of primary mammary epithelial cells. Our results underscore the critical need for thorough characterization of biosensor-carrying models before their application in specific research contexts. Additionally, this work highlights the influence of hormonal and genetic factors on mammary gland development and emphasizes the importance of careful consideration when selecting biosensor strains for mammary studies.
- MeSH
- Biosensing Techniques * methods MeSH
- Epithelial Cells metabolism drug effects MeSH
- Estrogens * metabolism MeSH
- Extracellular Signal-Regulated MAP Kinases metabolism MeSH
- Genetic Background MeSH
- Mammary Glands, Animal * growth & development drug effects MeSH
- Mice, Inbred C57BL * MeSH
- Mice, Inbred ICR MeSH
- Mice, Transgenic * MeSH
- Mice MeSH
- Fluorescence Resonance Energy Transfer methods MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
We present new developments for an ab-initio model of the neutron relative biological effectiveness (RBE) in inducing specific classes of DNA damage. RBE is evaluated as a function of the incident neutron energy and of the depth inside a human-sized reference spherical phantom. The adopted mechanistic approach traces neutron RBE back to its origin, i.e. neutron physical interactions with biological tissues. To this aim, we combined the simulation of radiation transport through biological matter, performed with the Monte Carlo code PHITS, and the prediction of DNA damage using analytical formulas, which ground on a large database of biophysical radiation track structure simulations performed with the code PARTRAC. In particular, two classes of DNA damage were considered: sites and clusters of double-strand breaks (DSBs), which are known to be correlated with cell fate following radiation exposure. Within a coherent modelling framework, this approach tackles the variation of neutron RBE in a wide energy range, from thermal neutrons to neutrons of hundreds of GeV, and reproduces effects related to depth in the human-sized receptor, as well as to the receptor size itself. Besides providing a better mechanistic understanding of neutron biological effectiveness, the new model can support better-informed decisions for radiation protection: indeed, current neutron weighting (ICRP)/quality (U.S. NRC) factors might be insufficient for use in some radiation protection applications, because they do not account for depth. RBE predictions obtained with the reported model were successfully compared to the currently adopted radiation protection standards when the depth information is not relevant (at the shallowest depth in the phantom or for very high energy neutrons). However, our results demonstrate that great care is needed when applying weighting factors as a function of incident neutron energy only, not explicitly considering RBE variation in the target. Finally, to facilitate the use of our results, we propose look-up RBE tables, explicitly considering the depth variable, and an analytical representation of the maximal RBE vs. neutron energy.
Quantitative genomic mapping of DNA damage may provide insights into the underlying mechanisms of damage and repair. Sequencing based approaches are bound to the limitations of PCR amplification bias and read length which hamper both the accurate quantitation of damage events and the ability to map them to structurally complex genomic regions. Optical Genome mapping in arrays of parallel nanochannels allows physical extension and genetic profiling of millions of long genomic DNA fragments, and has matured to clinical utility for characterization of complex structural aberrations in cancer genomes. Here we present a new mapping modality, Repair-Assisted Damage Detection - Optical Genome Mapping (RADD-OGM), a method for single-molecule level mapping of DNA damage on a genome-wide scale. Leveraging ultra-long reads to assemble the complex structure of a sarcoma cell-line genome, we mapped the genomic distribution of oxidative DNA damage, identifying regions more susceptible to DNA oxidation. We also investigated DNA repair by allowing cells to repair chemically induced DNA damage, pinpointing locations of concentrated repair activity, and highlighting variations in repair efficiency. Our results showcase the potential of the method for toxicogenomic studies, mapping the effect of DNA damaging agents such as drugs and radiation, as well as following specific DNA repair pathways by selective induction of DNA damage. The facile integration with optical genome mapping enables performing such analyses even in highly rearranged genomes such as those common in many cancers, a challenging task for sequencing-based approaches.
- MeSH
- Bromates toxicity MeSH
- Humans MeSH
- Chromosome Mapping * instrumentation methods MeSH
- Microfluidic Analytical Techniques * instrumentation methods MeSH
- Cell Line, Tumor MeSH
- Nanotechnology * instrumentation methods MeSH
- DNA Repair genetics MeSH
- Oxidative Stress drug effects genetics MeSH
- DNA Damage * genetics MeSH
- Gene Expression Regulation MeSH
- Gene Expression Profiling MeSH
- Toxicogenetics * instrumentation methods MeSH
- DNA Copy Number Variations MeSH
- Single Molecule Imaging * instrumentation methods MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
The hippocampus (HPC) is essential for navigation and memory, tracking environmental continuity and change, including navigation relative to moving targets. CA1 ensembles expressing immediate-early gene (IEG) Arc and Homer1a RNA are contextually specific. While IEG expression correlates with HPC-dependent task demands, the effects of behavioral demands on IEG-expressing ensembles remain unclear. In three experiments, we investigated the effects of context switch, sustained presence, and task demands on dorso-proximal CA1 IEG+ ensembles in rats. Experiment 1 showed that the size of IEG+ (Arc, Homer1a RNA) ensembles dropped to baseline during uninterrupted 30-min exploration, reflecting familiarization, unless a context switch was present. Context-specificity of the ensembles depended on both environment identity and timing of the context switch. Experiment 2 found no effect of HPC-dependent mobile robot avoidance or HPC-independent avoidance of a stationary robot on IEG+ ensembles beyond mere exploration. Experiment 3 replicated these findings for c-Fos protein. The data suggest that IEG+ ensembles are driven by a context switch and shrink over time during sustained presence in the same environment. We found no evidence of task demands or their change affecting the size, stability over time, or task-specificity of IEG+ ensembles. These results shed light on the temporal dynamics of CA1 IEG+ ensembles, and their control by contextual and behavioral factors.
- MeSH
- Behavior, Animal physiology MeSH
- Cytoskeletal Proteins genetics metabolism MeSH
- CA1 Region, Hippocampal * metabolism physiology MeSH
- Homer Scaffolding Proteins * metabolism genetics MeSH
- Rats MeSH
- Genes, Immediate-Early * physiology MeSH
- Rats, Long-Evans * MeSH
- Nerve Tissue Proteins genetics metabolism MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
During hypoxia, tissues are subjected to an inadequate oxygen supply, disrupting the balance needed to maintain normal function. This deficiency can occur due to reduced oxygen delivery caused by impaired blood flow or a decline in the blood's ability to carry oxygen. In tumors, hypoxia and vascularization play crucial roles, shaping their microenvironments and influencing cancer progression, response to treatment and metastatic potential. This chapter provides guidance on the use of non-invasive imaging methods including Positron Emission Tomography and Magnetic Resonance Imaging to study tumor oxygenation in pre-clinical settings. These imaging techniques offer valuable insights into tumor vascularity and oxygen levels, aiding in understanding tumor behavior and treatment effects. For example, PET imaging uses tracers such as [18F]-fluoromisonidazole (FMISO) to visualize hypoxic areas within tumors, while MRI complements this with anatomical and functional images. Although directly assessing tumor hypoxia with MRI remains challenging, techniques like Blood Oxygen Level Dependent (BOLD) and Dynamic Contrast-Enhanced MRI (DCE-MRI) provide valuable information. BOLD can track changes in oxygen levels during oxygen challenges, while DCE-MRI offers real-time access to perfusion and vessel permeability data. Integrating data from these imaging modalities can help assess oxygen supply, refine treatment strategies, enhance therapeutic effectiveness, and ultimately improve patient outcomes.
- MeSH
- Hypoxia diagnostic imaging MeSH
- Oxygen metabolism MeSH
- Humans MeSH
- Magnetic Resonance Imaging * methods MeSH
- Misonidazole analogs & derivatives MeSH
- Mice MeSH
- Tumor Hypoxia MeSH
- Neoplasms diagnostic imaging blood supply pathology MeSH
- Neovascularization, Pathologic diagnostic imaging pathology MeSH
- Positron-Emission Tomography * methods MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
The molecular mechanisms linking obstructive sleep apnea syndrome (OSA) to obesity and the development of metabolic diseases are still poorly understood. The role of hypoxia (a characteristic feature of OSA) in excessive fat accumulation has been proposed. The present study investigated the possible effects of hypoxia (4% oxygen) on de novo lipogenesis by tracking the major carbon sources in differentiating 3T3-L1 adipocytes. Gas-permeable cultuware was employed to cultivate 3T3-L1 adipocytes in hypoxia (4%) for 7 or 14 days of differentiation. We investigated the contribution of glutamine, glucose or acetate using 13C or 14C labelled carbons to the newly synthesized lipid pool, changes in intracellular lipid content after inhibiting citrate- or acetate-dependent pathways and gene expression of involved key enzymes. The results demonstrate that, in differentiating adipocytes, hypoxia decreased the synthesis of lipids from glucose (44.1 ± 8.8 to 27.5 ± 3.0 pmol/mg of protein, p < 0.01) and partially decreased the contribution of glutamine metabolized through the reverse tricarboxylic acid cycle (4.6% ± 0.2-4.2% ± 0.1%, p < 0.01). Conversely, the contribution of acetate, a citrate- and mitochondria-independent source of carbons, increased upon hypoxia (356.5 ± 71.4 to 649.8 ± 117.5 pmol/mg of protein, p < 0.01). Further, inhibiting the citrate- or acetate-dependent pathways decreased the intracellular lipid content by 58% and 73%, respectively (p < 0.01) showing the importance of de novo lipogenesis in hypoxia-exposed adipocytes. Altogether, hypoxia modified the utilization of carbon sources, leading to alterations in de novo lipogenesis in differentiating adipocytes and increased intracellular lipid content.
- MeSH
- Acetates * metabolism pharmacology MeSH
- Cell Differentiation * drug effects MeSH
- 3T3-L1 Cells * MeSH
- Citric Acid Cycle MeSH
- Glucose * metabolism MeSH
- Glutamine * metabolism MeSH
- Cell Hypoxia MeSH
- Lipids biosynthesis MeSH
- Lipogenesis * drug effects MeSH
- Lipid Metabolism drug effects MeSH
- Mice MeSH
- Adipocytes * metabolism drug effects MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
