Time-dependent parametric surface models of the human heart

1999 ◽  
Author(s):  
Bloor ◽  
Wilson ◽  
Knudsen ◽  
Knudsen ◽  
Holden
Keyword(s):  
Human Heart ◽  
Time Dependent ◽  
Parametric Surface ◽  
Surface Models

Abstract 19: Myocyte Turnover in the Aging Human Heart

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Barbara OgÓrek ◽  
Toru Hosoda ◽  
Carlos Rondon ◽  
Narasimman Gurusamy ◽  
Alessandro Gatti ◽  
...  
Keyword(s):  
Human Heart ◽  
Age Distribution ◽  
Young Female ◽  
Time Dependent ◽  
Normal Female ◽  
Senescent Phenotype ◽  
Myocyte Apoptosis ◽  
Gender Based ◽  
And Gender ◽  
Myocardial Aging

The controversy on the growth reserve of the adult human heart has not been resolved and the extent of myocyte renewal reported by different groups varies significantly. Additionally, myocyte regeneration has been claimed to decrease with aging, although cell death is markedly enhanced in the old myocardium. Thus, the effects of age and gender on the magnitude of myocyte turnover were determined. Myocyte replication, senescence and apoptosis were measured in normal female and male human hearts collected from patients 19 to 104 years of age who died from causes other than cardiovascular diseases. Myocardial aging was characterized by a time-dependent increase in the generation of amplifying cardiomyocytes in women and men. Levels of Ki67 and phospho-H3 were comparable in the young female and male heart but differed later in life. As a function of age, the pool of amplifying myocytes was 2-fold higher in women than men, pointing to enhanced myocyte renewal in the female heart. The frequency of p16 INK4a -positive myocytes was higher in men than in women. From 19 to 104 years of age, the time-dependent increase in senescent myocytes was 0.68% per year in women and 0.89% per year in men; the 31% higher rate of accumulation of old myocytes in the aging male heart was significant. Myocyte apoptosis occurred only in p16 INK4a -positive cells and was consistently higher in men than in women at all age intervals. However, the increase in myocyte apoptosis with age did not differ with gender. Based on these parameters, we measured the average age of cardiomyocytes, their age distribution, turnover rate and time to acquire the senescent phenotype to define the biology of myocardial aging as a function of lifespan. In the female heart, myocyte turnover occurs at a rate of 10%, 15% and 40% per year at 20, 60 and 100 years of age, respectively. Corresponding values in the male heart are 7%, 12% and 32% per year, documenting that cardiomyogenesis involves a large and progressively increasing number of parenchymal cells with aging. In conclusion, the human heart is a highly dynamic organ in which progressive myocyte loss is at least in part counteracted by enhanced myocyte renewal. Myocyte regeneration in the physiologically aging heart takes place at previously unexpected levels in both women and men.

scholarly journals Shape Parameterization of the Time-Dependent Geometry of the Heart for Steady Fluid Dynamical Analysis

2001 ◽  
Vol 3 (4) ◽  
pp. 221-230 ◽  
Author(s):  
C. J. Evans ◽  
M. I. G. Bloor ◽  
M. J. Wilson
Keyword(s):  
Differential Equation ◽  
Fluid Dynamics ◽  
Human Heart ◽  
Elliptic Partial Differential Equation ◽  
Parametric Model ◽  
Time Dependent ◽  
Dynamical Analysis ◽  
Geometry Model ◽  
Inner Surface ◽  
Shape Parameterization

A parametric model of the complex time-dependent geometry of the ventricles of the human heart is constructed. The geometry model is created by means of a boundary value approach, solving an elliptic partial differential equation to generate a representation of the inner surface of the ventricles. The technique provides a closed-form description of the geometry with the advantage that the geometry can be readily changed without introducing holes or discontinuities in the surface. It also allows a straightforward link to analysis, facilitating the calculation of physical properties such as those relevant to fluid dynamics. As an application of this work, the geometry model is combined with commercial CFD software to analyse the blood flow in the heart. Steady-state calculations are performed at various time steps to follow the evolution of the fluid flow.

scholarly journals Analysis of the accuracy of the reproduction of the solid model from the parametric surface in the module Reverse Engineering NX system

Mechanik ◽  
2019 ◽  
Vol 92 (7) ◽  
pp. 468-470
Author(s):  
Jan Burek ◽  
Barbara Jamuła ◽  
Rafał Flejszar
Keyword(s):  
Reverse Engineering ◽  
Digital Model ◽  
Solid Model ◽  
Parametric Surface ◽  
Surface Models

An analysis of the accuracy of generating a solid mode based on the created surfaces is presented. In the process of creating a digital model, reconstructive engineering methods were used. The accuracy of mapping of the created solid model was determined on the basis of surface models generated by changing the tolerance value of triangles.

40 MicroRNAs in the human heart: a clue to fetal gene reprogramming in heart failure

2007 ◽  
Vol 6 (1) ◽  
pp. 3-3
Author(s):  
T THUM ◽  
P GALUPPO ◽  
S KNEITZ ◽  
C WOLF ◽  
L VANLAAKE ◽  
...  
Keyword(s):  
Heart Failure ◽  
Human Heart
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