scholarly journals Explicit solutions of a simplified model of capillary sprout growth during tumor angiogenesis

1996 ◽  
Vol 9 (1) ◽  
pp. 69-74 ◽  
Author(s):  
H.M. Byrne ◽  
M.A.J. Chaplain
2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e22121-e22121
Author(s):  
Y. Xu ◽  
J. Fan ◽  
X. Yang ◽  
J. Zhou ◽  
S. Qiu

e22121 Background: To investigate the prognostic values of putative hepatic stem/progenitor cells (HSCs/HPCs) biomarkers in hepatocellular carcinoma (HCC) patients. Methods: Fourteen biomarkers related with HSCs/HPCs or tumor angiogenesis were assessed by qRT-PCR and then validated by tissue microarrays (TMAs) in three independent cohorts of HCC patients underwent curative resection (n=67, 314 and 73). Results: Most of the biomarkers were found over-expressed in recurrent HCC patients by qRT-PCR. HSCs/HPCs biomarkers cytokeratin 19, ABCG2, CD133, Nestin, CD44 and angiogenesis agents CD34, VEGF and PD-ECGF, were confirmed as significant predictors for overall survival (OS) and/or relapse-free survival (RFS) in TMAs analysis. Compared with the low HSCs/HPCs profile group, patients with high HSCs/HPCs profile had significantly lower OS and RFS (p<0.0001), expressed higher VEGF levels (p = 0.012) and microvessel density (MVD, determined by CD34 immunostaining, p = 0.030). Based on Cox regression, a simplified model including CD133, CD44, Nestin, and MVD was constructed and confirmed as an independent predictor for OS (p<0.0001) and RFS (p<0.0001), regardless of alpha-fetoprotein level, tumor stage and recurrence time (p<0.0001 for all). Conclusions: High expression levels of HSCs/HPCs biomarkers are related to tumor angiogenesis and poor prognosis of HCC. The simplified model based on HSCs/HPCs and tumor angiogenesis profile can be used to classify HCC patients with high risk of tumor recurrence after operation. No significant financial relationships to disclose.


Author(s):  
Christelle Lusso ◽  
Francois Bouchut ◽  
Alexandre Ern ◽  
Anne Mangeney

This work is devoted to an analytical description of the dynamics of the static/flowing interface in thin dry granular flows. Our starting point is the asymptotic model derived by Bouchut et al. (2016) from a free surface incompressible model with viscoplastic rheology including a Drucker--Prager yield stress. This asymptotic model is based on the thin-layer approximation (the flow is thin in the direction normal to the topography compared to its down-slope extension), but the equations are not depth-averaged. In addition to the velocity, the model includes a free surface at the top of the flow and a free time-dependent static/flowing interface at the bottom. In the present work, we simplify this asymptotic model by decoupling the space coordinates, and keeping only the dependence on time and on the normal space coordinate $Z$. We introduce a time- and $Z$-dependent source term, assumed here to be given, which represents the opposite of the net force acting on the flowing material, including gravity, pressure gradient, and internal friction. We prove several properties of the resulting simplified model that has a time- and $Z$-dependent velocity and a time-dependent static/flowing interface as unknowns. The crucial advantage of this simplified model is that it can provide explicit solutions in the inviscid case, for different shapes of the source term. These explicit inviscid solutions exhibit a rich behaviour and qualitatively reproduce some physical features observed in granular flows.


2019 ◽  
Vol 47 (5) ◽  
pp. 1543-1555 ◽  
Author(s):  
Maurizio Mongiat ◽  
Simone Buraschi ◽  
Eva Andreuzzi ◽  
Thomas Neill ◽  
Renato V. Iozzo

Abstract The extracellular matrix is a network of secreted macromolecules that provides a harmonious meshwork for the growth and homeostatic development of organisms. It conveys multiple signaling cascades affecting specific surface receptors that impact cell behavior. During cancer growth, this bioactive meshwork is remodeled and enriched in newly formed blood vessels, which provide nutrients and oxygen to the growing tumor cells. Remodeling of the tumor microenvironment leads to the formation of bioactive fragments that may have a distinct function from their parent molecules, and the balance among these factors directly influence cell viability and metastatic progression. Indeed, the matrix acts as a gatekeeper by regulating the access of cancer cells to nutrients. Here, we will critically evaluate the role of selected matrix constituents in regulating tumor angiogenesis and provide up-to-date information concerning their primary mechanisms of action.


2001 ◽  
Vol 120 (5) ◽  
pp. A296-A296
Author(s):  
C DAI ◽  
G STEVENL ◽  
M GEE ◽  
W LEE ◽  
H LEE ◽  
...  

2010 ◽  
Vol 48 (08) ◽  
Author(s):  
N Azoitei ◽  
GV Pusapati ◽  
A Kleger ◽  
C Brunner ◽  
F Genze ◽  
...  

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