scholarly journals Cellular Automaton Simulation of Tumour Growth – Equivocal Relationships between Simulation Parameters and Morphologic Pattern Features

1998 ◽  
Vol 17 (2) ◽  
pp. 71-82 ◽  
Author(s):  
Josef Smolle
Keyword(s):  
Cell Adhesion ◽  
Cellular Automaton ◽  
Cell Motility ◽  
Tumour Cell ◽  
Growth Control ◽  
Tumour Cells ◽  
Reliable Estimate ◽  
Morphometric Features ◽  
Simulation Parameter ◽  
Simulation Parameters

Objective:To develop an interpretation procedure which estimates simulation parameters (tumour cell motility, tumour cell adhesion, autocrine and paracrine growth control, stroma destruction) of simulated patterns solely based on morphometric features of the morphologic pattern.Methods:A cellular automaton computer simulation program was developed which produces morphologic patterns by growth of a seed of tumour cells. At the beginning of each simulation run certain simulation parameters are assigned to the tumour cells. After the run has been completed, the resulting pattern is evaluated by a set of morphometric features. Simulation parameters and resulting morphometric features of 27,800 simulations were stored in a database and were used for the evaluation of potential relationships.Results:Correlation analysis showed highly significant correlations between morphometric features on the one hand and the preset simulation parameters (tumour cell motility, tumour cell adhesion, autocrine and paracrine growth control, stroma destruction) on the other. Correlation coefficients, however, varied from 0.72 to 0.99. When only one simulation parameter varied while all others were kept constant, morphometric features yielded a highly reliable estimate of the particular simulation parameter. When variability was extended to 4 simulation parameters, morphometric features were less effective in estimating the setting of the parameters. Though in all patterns tested several possible simulation parameter constellations could be ruled out, morphometric features were usually compatible with more than one set of simulation parameters thus preventing a straightforward interpretation.Conclusions:Though simulation parameters significantly and reproducibly influence the resulting morphologic pattern as characterized by morphometric features, estimates of the simulation parameters based on morphometric features yield equivocal results.

scholarly journals LRP-1 Commands Two Parallel Signalling Mechanisms to Support Constitutive Tumour Cell Motility in the Absence of Blood Supply

2021 ◽  
Author(s):  
Wei Li ◽  
Cheng Chang ◽  
Xin Tang ◽  
Daniel Mosallaei ◽  
Mei Chen ◽  
...  
Keyword(s):  
Cell Motility ◽  
Blood Supply ◽  
Tumour Cell ◽  
Low Density Lipoprotein ◽  
Critical Role ◽  
Density Lipoprotein ◽  
Tumour Cells ◽  
Migration And Invasion ◽  
Autocrine Loop

Tumour cells often face the stress of ischemic (nutrient paucity and hypoxia) environment and must act self-sufficient to migrate toward the nearest blood supply or die. The mechanism that supports the constitutive motility of tumour cells under stress is poorly understood. We and others have previously shown that the low-density lipoprotein receptor-related protein 1 (LRP-1) plays a critical role in tumour cell migration and invasion in vitro and tumour formation in mice. Herein we show that depletion of LRP-1 completely abolishes the self-supported and serum-independent tumour cell motility. More intriguingly, we demonstrate that LRP-1 commands the full tumour cell motility by connecting with two independent cell surface signalling pathways. First, LRP-1 mediates secreted Hsp90α signalling via the Hsp90α > LRP-1 receptor autocrine loop for a half of tumour cell motility. Second, LRP1 stabilizes constitutively activated EGFR signalling that contributes the other half of tumour cell motility. Only combined inhibitions of the secreted Hsp90α autocrine and the EGFR signalling reproduces the effect of LRP1 down-regulation on constitutive tumour cell motility. This study reveals a novel mechanism of how tumour cells migrate in the absence of blood support.

Sensitivity Analysis and Selection of Check Index of Signal Intersection Simulation Model Based on VISSIM

2019 ◽  
Vol 2 (5) ◽  
Author(s):  
Mengda Zhang ◽  
Chenjing Zhou ◽  
Tian-tian Zhang ◽  
Yan Han
Keyword(s):  
Sensitivity Analysis ◽  
Simulation Model ◽  
Optimal Process ◽  
Parameter Calibration ◽  
Index Set ◽  
The Core ◽  
Core Module ◽  
Simulation Parameter ◽  
Simulation Parameters ◽  
Selection Of

Selecting check index quantitatively is the core of the calibration of micro traffic simulation parameters at signal intersection. Five indexes in the node (intersection) module of VISSIM were selected as the check index set. Twelve simulation parameters in the core module were selected as the simulation parameters set. Optimal process of parameter calibration was proposed and model of the intersection of Huangcun west street and Xinghua street in Beijing was built in VISSIM to verify it. The sensitivity analysis between each check index and simulation parameter in their own set was conducted respectively. Sensitive parameter sets of different check indices were obtained and compared. The results show that different indexes have different size of set, and average vehicle delay's is maximum, so it's necessary to select index quantitatively. The results can provide references for scientific selection of the check indexes and improve the study efficiency of parameter calibration.

scholarly journals Connections between the cell cycle, cell adhesion and the cytoskeleton

2019 ◽  
Vol 374 (1779) ◽  
pp. 20180227 ◽  
Author(s):  
Matthew C. Jones ◽  
Junzhe Zha ◽  
Martin J. Humphries
Keyword(s):  
Cell Cycle ◽  
Cell Adhesion ◽  
Morphological Changes ◽  
Tumour Progression ◽  
Genetic Material ◽  
Growth Control ◽  
Normal Growth ◽  
Parent Cell ◽  
Interdisciplinary Approaches ◽  
Spatio Temporal

Cell division, the purpose of which is to enable cell replication, and in particular to distribute complete, accurate copies of genetic material to daughter cells, is essential for the propagation of life. At a morphological level, division not only necessitates duplication of cellular structures, but it also relies on polar segregation of this material followed by physical scission of the parent cell. For these fundamental changes in cell shape and positioning to be achieved, mechanisms are required to link the cell cycle to the modulation of cytoarchitecture. Outside of mitosis, the three main cytoskeletal networks not only endow cells with a physical cytoplasmic skeleton, but they also provide a mechanism for spatio-temporal sensing via integrin-associated adhesion complexes and site-directed delivery of cargoes. During mitosis, some interphase functions are retained, but the architecture of the cytoskeleton changes dramatically, and there is a need to generate a mitotic spindle for chromosome segregation. An economical solution is to re-use existing cytoskeletal molecules: transcellular actin stress fibres remodel to create a rigid cortex and a cytokinetic furrow, while unipolar radial microtubules become the primary components of the bipolar spindle. This remodelling implies the existence of specific mechanisms that link the cell-cycle machinery to the control of adhesion and the cytoskeleton. In this article, we review the intimate three-way connection between microenvironmental sensing, adhesion signalling and cell proliferation, particularly in the contexts of normal growth control and aberrant tumour progression. As the morphological changes that occur during mitosis are ancient, the mechanisms linking the cell cycle to the cytoskeleton/adhesion signalling network are likely to be primordial in nature and we discuss recent advances that have elucidated elements of this link. A particular focus is the connection between CDK1 and cell adhesion. This article is part of a discussion meeting issue ‘Forces in cancer: interdisciplinary approaches in tumour mechanobiology’.

scholarly journals Simulation Parameter Test and Seepage Effect Analysis of Pile-Anchor Support for Binary Slope

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Xuhe Gao ◽  
Weiping Tian ◽  
Zhipei Zhang ◽  
Jiachun Li ◽  
Hongliang Qi ◽  
...  
Keyword(s):  
Steady State ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Guizhou Province ◽  
Inspection Method ◽  
Safety Control ◽  
Supporting Structure ◽  
Slope Excavation ◽  
Simulation Parameter ◽  
Simulation Parameters

It is a difficult point in the field of geotechnical engineering to test the simulation parameters of the pile-anchor supporting structure of slope excavation and analyze the effect of seepage on the stress of the structure. This study relies on the right side slope treatment project of a highway in Guizhou Province. Aiming at the defect that the current numerical simulation parameter selection is fuzzy, the deep displacement monitoring data and P value inspection method are used to check the simulation parameters. We establish a 2D finite element model of slope excavation and support. The superposition calculation method of pore water pressure was used to analyze the stress characteristics of the slope-supporting structure after applying steady-state seepage. The analysis shows the following. ① Initial support stage: the steady-state seepage causes the axial force extreme value of the prestressed anchor cable to increase by 11.22% at this stage. ② Secondary support stage: the steady-state seepage reduces the shear limit of the antislide pile by 3.11% and the bending moment by 14.90%. ③ Comparative analysis of the two supporting phases: the newly constructed pile-anchor supporting structure has a significant effect on the original pile-anchor supporting structure. At the same time, the bending and shearing resistance of the newly added antislide piles has not been fully exerted. The research results provide new ideas for the research on the safety control ability of the slope support construction process.

scholarly journals Monoclonal Antibodies as Immune Modulators for Cancer Therapy

1992 ◽  
Vol 3 (suppl b) ◽  
pp. 20-25
Author(s):  
Robert O Dillman
Keyword(s):  
Monoclonal Antibodies ◽  
Cancer Therapy ◽  
Immune Cells ◽  
Tumour Cell ◽  
Interleukin 2 ◽  
Tumour Cells ◽  
Host Immune System ◽  
Biological Behaviour ◽  
Immune Modulators ◽  
The Status

Monoclonal antibodies may modulate immune and/or biological responses alone, or as carriers of specific agents. Monoclonal antibodies directed against tumours may be indirectly cytotoxic by modulation of antibody-dependent, cell-mediated cytotoxicity or complement-mediated cytotoxicity. Monoclonal antibodies directed against certain tumour cell receptors may alter the biological behaviour of tumour cells such as blocking or downregulation of growth factors essential to tumour cell proliferation. Monoclonal antibodies directed to certain receptors on host immune cells. such as the CD3 receptor on T lymphocytes. may activate those cells and increase their cytotoxicity. Antitumour monoclonal antibodies can serve as carriers of interferons, interleukin-2, tumour necrosis factor and other lymphokines and cytokines to modulate selectively the cytotoxic potential of immune cells in the vicinity of tumour cells. Cytotoxic chemotherapy agents conjugated to antitumour monoclonal antibodies may be processed differently so that they bypass certain mechanisms of drug resistance. The penultimate application of monoclonal antibodies in cancer therapy is to combine various monoclonal antibodies and immunoconjugates for selective combination therapy based on known antigenic tumour cell determinants and the status of the host immune system.

Lymphocyte-facilitated tumour cell adhesion to endothelial cells: the role of high affinity leucocyte integrins

Pathology ◽  
2003 ◽  
Vol 35 (1) ◽  
pp. 50-55
Author(s):  
Paul J. Neeson ◽  
Peter J. Thurlow ◽  
Gary P. Jamieson ◽  
Chris Bradley
Keyword(s):  
Endothelial Cells ◽  
Cell Adhesion ◽  
Tumour Cell ◽  
High Affinity
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