scholarly journals Mathematical Modelling of Glioblastomas Invasion within the Brain: A 3D Multi-Scale Moving-Boundary Approach

Mathematics ◽  
2021 ◽  
Vol 9 (18) ◽  
pp. 2214
Author(s):  
Szabolcs Suveges ◽  
Kismet Hossain-Ibrahim ◽  
J. Douglas Steele ◽  
Raluca Eftimie ◽  
Dumitru Trucu
Keyword(s):  
Moving Boundary ◽  
Diffusion Tensor ◽  
Initial Conditions ◽  
Survival Rates ◽  
Cell Dynamics ◽  
Diffusion Term ◽  
Multi Scale ◽  
Single Scale ◽  
Invasion Patterns

Brain-related experiments are limited by nature, and so biological insights are often limited or absent. This is particularly problematic in the context of brain cancers, which have very poor survival rates. To generate and test new biological hypotheses, researchers have started using mathematical models that can simulate tumour evolution. However, most of these models focus on single-scale 2D cell dynamics, and cannot capture the complex multi-scale tumour invasion patterns in 3D brains. A particular role in these invasion patterns is likely played by the distribution of micro-fibres. To investigate the explicit role of brain micro-fibres in 3D invading tumours, in this study, we extended a previously introduced 2D multi-scale moving-boundary framework to take into account 3D multi-scale tumour dynamics. T1 weighted and DTI scans are used as initial conditions for our model, and to parametrise the diffusion tensor. Numerical results show that including an anisotropic diffusion term may lead in some cases (for specific micro-fibre distributions) to significant changes in tumour morphology, while in other cases, it has no effect. This may be caused by the underlying brain structure and its microscopic fibre representation, which seems to influence cancer-invasion patterns through the underlying cell-adhesion process that overshadows the diffusion process.

scholarly journals Seed banks alter metacommunity diversity: the interactive effects of competition, germination, and survival

2021 ◽  
Author(s):  
Nathan I. Wisnoski ◽  
Lauren G. Shoemaker
Keyword(s):  
Survival Rates ◽  
Nonlinear Effects ◽  
Spatial Diversity ◽  
Seed Banks ◽  
Interactive Effects ◽  
Multi Scale ◽  
Variable Environments ◽  
Empirical Tests ◽  
Temporal And Spatial

AbstractDispersal and dormancy are two common strategies allowing for species persistence and the maintenance of ecological diversity in variable environments. However, theory and empirical tests of spatial diversity patterns tend to examine either mechanism in isolation. Here, we developed a stochastic, spatially explicit metacommunity model incorporating seed banks with varying germination and survival rates. We found that dormancy and dispersal had interactive, nonlinear effects on the maintenance and distribution of metacommunity diversity, where scale-dependent effects of seed banks were modified by local competitive interactions and dispersal. The interplay between seed germination and survival regulated the benefits of seed banks for diversity. Our study shows that the role of seed banks depends critically on spatial processes, and that classic predictions for how dispersal affects metacommunity diversity can be strongly influenced by dormancy. Together, these results highlight the need to consider both temporal and spatial storage when predicting multi-scale patterns of diversity.

scholarly journals Multi-Neighborhood Convolutional Networks

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Elnaz Barshan ◽  
Paul Fieguth ◽  
Alexander Wong
Keyword(s):  
Feature Learning ◽  
Scale Space ◽  
Image Features ◽  
Superior Performance ◽  
Convolutional Networks ◽  
Multi Scale ◽  
Image Characteristics ◽  
Single Scale ◽  
Nonlinear Scale

<p>We explore the role of scale for improved feature learning in convolutional<br />networks. We propose multi-neighborhood convolutional<br />networks, designed to learn image features at different levels of<br />detail. Utilizing nonlinear scale-space models, the proposed multineighborhood<br />model can effectively capture fine-scale image characteristics<br />(i.e., appearance) using a small-size neighborhood, while<br />coarse-scale image structures (i.e., shape) are detected through<br />a larger neighborhood. The experimental results demonstrate the<br />superior performance of the proposed multi-scale multi-neighborhood<br />models over their single-scale counterparts.</p>

scholarly journals Structural and Functional Imaging in Glioma Management

Neurosurgery ◽  
2020 ◽  
Author(s):  
Bledi C Brahimaj ◽  
Ryan B Kochanski ◽  
John J Pearce ◽  
Melike Guryildirim ◽  
Carter S Gerard ◽  
...  
Keyword(s):  
Diffusion Tensor ◽  
Imaging Modalities ◽  
Hemispheric Dominance ◽  
Tumor Control ◽  
Histopathological Diagnosis ◽  
Glioma Surgery ◽  
Multiple Modalities ◽  
Advantages And Disadvantages ◽  
Multiple Imaging

Abstract The goal of glioma surgery is maximal safe resection in order to provide optimal tumor control and survival benefit to the patient. There are multiple imaging modalities beyond traditional contrast-enhanced magnetic resonance imaging (MRI) that have been incorporated into the preoperative workup of patients presenting with gliomas. The aim of these imaging modalities is to identify cortical and subcortical areas of eloquence, and their relationship to the lesion. In this article, multiple modalities are described with an emphasis on the underlying technology, clinical utilization, advantages, and disadvantages of each. functional MRI and its role in identifying hemispheric dominance and areas of language and motor are discussed. The nuances of magnetoencephalography and transcranial magnetic stimulation in localization of eloquent cortex are examined, as well as the role of diffusion tensor imaging in defining normal white matter tracts in glioma surgery. Lastly, we highlight the role of stimulated Raman spectroscopy in intraoperative histopathological diagnosis of tissue to guide tumor resection. Tumors may shift the normal arrangement of functional anatomy in the brain; thus, utilization of multiple modalities may be helpful in operative planning and patient counseling for successful surgery.

Void-dynamics in nano-wires and the role of microstructure investigated via a multi-scale physics-based model

2021 ◽  
Vol 129 (12) ◽  
pp. 125102
Author(s):  
A. S. Saleh ◽  
H. Ceric ◽  
H. Zahednamesh
Keyword(s):  
Multi Scale ◽  
Void Dynamics ◽  
Nano Wires

scholarly journals Prognostic and Clinicopathological Significance of MiR-155 in Breast Cancer: A Systematic Review

2020 ◽  
Vol 21 (16) ◽  
pp. 5834
Author(s):  
Anna Maria Grimaldi ◽  
Silvia Nuzzo ◽  
Gerolama Condorelli ◽  
Marco Salvatore ◽  
Mariarosaria Incoronato
Keyword(s):  
Breast Cancer ◽  
Systematic Review ◽  
Prognostic Biomarker ◽  
Survival Rates ◽  
Prognostic Significance ◽  
Unmet Need ◽  
Non Invasive ◽  
Clinicopathological Significance ◽  
Present Systematic Review

There is an unmet need for novel non-invasive prognostic molecular tumour markers for breast cancer (BC). Accumulating evidence shows that miR-155 plays a pivotal role in tumorigenesis. Generally, miR-155 is considered an oncogenic miRNA promoting tumour growth, angiogenesis and aggressiveness of BC. Therefore, many researchers have focused on its use as a prognostic biomarker and therapeutic target. However, its prognostic value for BC patients remains controversial. To address this issue, the present systematic review aims to summarize the available evidence and give a picture of a prognostic significance of miR-155 in BC pathology. All eligible studies were searched on PubMed and EMBASE databases through various search strategies. Starting from 289 potential eligible records, data were examined from 28 studies, comparing tissue and circulating miR-155 expression levels with clinicopathological features and survival rates in BC patients. We discuss the pitfalls and challenges that need to be assessed to understand the power of miR-155 to respond to real clinical needs, highlighting the consistency, robustness or lack of results obtained to sate in translating this molecule to clinical practice. Our paper suggests that the prognostic role of miR-155 in the management of BC needs to be further verified.

scholarly journals Glioma Revisited: From Neurogenesis and Cancer Stem Cells to the Epigenetic Regulation of the Niche

2012 ◽  
Vol 2012 ◽  
pp. 1-20 ◽  
Author(s):  
Felipe de Almeida Sassi ◽  
Algemir Lunardi Brunetto ◽  
Gilberto Schwartsmann ◽  
Rafael Roesler ◽  
Ana Lucia Abujamra
Keyword(s):  
Stem Cells ◽  
Cancer Stem Cells ◽  
Cellular Proliferation ◽  
Survival Rates ◽  
Comprehensive Analysis ◽  
Heterogeneous Population ◽  
Aggressive Tumor ◽  
Epigenetic Modulation ◽  
The Brain

Gliomas are the most incident brain tumor in adults. This malignancy has very low survival rates, even when combining radio- and chemotherapy. Among the gliomas, glioblastoma multiforme (GBM) is the most common and aggressive type, and patients frequently relapse or become refractory to conventional therapies. The fact that such an aggressive tumor can arise in such a carefully orchestrated organ, where cellular proliferation is barely needed to maintain its function, is a question that has intrigued scientists until very recently, when the discovery of the existence of proliferative cells in the brain overcame such challenges. Even so, the precise origin of gliomas still remains elusive. Thanks to new advents in molecular biology, researchers have been able to depict the first steps of glioma formation and to accumulate knowledge about how neural stem cells and its progenitors become gliomas. Indeed, GBM are composed of a very heterogeneous population of cells, which exhibit a plethora of tumorigenic properties, supporting the presence of cancer stem cells (CSCs) in these tumors. This paper provides a comprehensive analysis of how gliomas initiate and progress, taking into account the role of epigenetic modulation in the crosstalk of cancer cells with their environment.

scholarly journals Spleen Tyrosine Kinase Inhibition Modulates p53 Activity

2017 ◽  
Vol 10 ◽  
pp. 117906601773156 ◽  
Author(s):  
Mohammad Althubiti
Keyword(s):  
Tyrosine Kinase ◽  
Survival Rates ◽  
Lymphocytic Leukemia ◽  
Spleen Tyrosine Kinase ◽  
Ht1080 Cell ◽  
P53 Expression ◽  
Chemical Inhibitors ◽  
Dependent Mechanism

Spleen tyrosine kinase (SYK) is a cytoplasmic enzyme that promotes survival and proliferation of B cells. SYK inhibition has shown promising results in the treatment of arthritis and chronic lymphocytic leukemia (CLL). However, in other context, it has been shown that SYK overexpression in epithelial cancer cells induced senescence in p53-dependent mechanism, which underscored its antineoplastic activity in vitro. Here, we show that SYK was induced in response of DNA damage in parallel with p53 levels. In addition, using chemical inhibitors of SYK reduced p53 levels in HCT116 and HT1080 cell lines, which underlines the role of SYK inhibition on p53 activity. Furthermore, SYK inhibition modulated the cell growth, which resulted in a decreasing in cell death. Interestingly, SYK expression showed a positive prognosis in patients with solid tumors in correlations with their survival rates, as expected negative correlation was seen between SYK expression and survival rate of patients with CLL. In conclusion, these findings demonstrate that SYK inhibition modulates p53 expression and activity in HCT116 and HT1080 cells. Reconsidering using of SYK inhibitors in clinical setting in the future should be evaluated carefully in accordance with these findings to prevent the formation of secondary malignancies.

Reassessment of transient permeability measurement for tight rocks: The role of boundary and initial conditions

2021 ◽  
pp. 104173
Author(s):  
Yue Wang ◽  
Zhiguo Tian ◽  
Steffen Nolte ◽  
Alexandra Amann-Hildenbrand ◽  
Bernhard M. Krooss ◽  
...  
Keyword(s):  
Initial Conditions ◽  
Permeability Measurement ◽  
Tight Rocks
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