Preclinical Determination of the Best Functional Position for Transcatheter Heart Valves Implanted in Surgical Sutureless Bioprostheses

An emission spectrometric method of analysis is described which permits duplicate analyses to be performed on 1-g specimens of tissue for 13 elements in the microgram percent range. Pig hearts were dissected into 17 separate pieces representing discrete anatomic sites. Samples were prepared for analysis by low temperature wet digestion. On the basis of their composition of the macro elements sodium, potassium, and phosphorus, these tissues could be divided into two groups: one including blood vessels and heart valves, and the other including ordinary and specialized myocardium. A method is described for adjusting the macro element composition of these tissues to that of a common matrix, thus allowing trace metal analysis of both groups of tissues to be performed using only a single set of standards. A solution of the ash was placed in hollow cup graphite electrodes with center posts, evaporated to dryness, and analyzed in the dc arc with a Jarrell-Ash model 66,000 direct reading emission spectrometer. At concentrations above 10 µg%, the coefficient of variation was about 10% for most of the trace metals studied.

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A Framework for Determination of Heart Valves’ Mechanical Properties Using Inverse-Modeling Approach

Functional Imaging and Modeling of the Heart - Lecture Notes in Computer Science ◽

10.1007/978-3-319-20309-6_33 ◽

2015 ◽

pp. 285-294 ◽

Cited By ~ 4

Author(s):

Ankush Aggarwal ◽

Michael S. Sacks

Keyword(s):

Mechanical Properties ◽

Inverse Modeling ◽

Heart Valves ◽

Modeling Approach

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Techniques in the Determination of the Flow Effectiveness of Prosthetic Heart Valves

Biomechanical Systems ◽

10.1201/9781420049534.ch-02 ◽

2000 ◽

Author(s):

Y Chew ◽

T Chew ◽

H Low ◽

W Lim

Keyword(s):

Heart Valves ◽

Prosthetic Heart Valves

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Implementation of an Automated Peripheral Resistance Device in a Mock Circulatory Loop With Characterization of Performance Values Using Simulink Simscape and Parameter Estimation

Journal of Medical Devices ◽

10.1115/1.4007458 ◽

2012 ◽

Vol 6 (4) ◽

Cited By ~ 5

Author(s):

Charles E. Taylor ◽

Gerald E. Miller

Keyword(s):

Parameter Estimation ◽

Heart Valves ◽

Water Solution ◽

Peripheral Resistance ◽

Ventricular Assist Devices ◽

Experimental Conditions ◽

Ventricular Assist

Accurate peripheral resistance simulation in a mock circulatory loop is critical to the evaluation of ventricular assist devices and heart valves. Implementation of an automated device that is capable of accurate resistance settings and precise reproduction of cardiovascular parameters allows for improved construction of experimental conditions within a mock circulatory loop. A mock circulatory loop resistor that employs a proportional valve design is proposed; a piston extending into the flow path to produce a resistance to flow. Real-time position feedback of the piston is used to determine orifice size, providing resolution in the change of resistance over time. Characterization of the physical system with The MathWorks SIMULINK™ SIMSCAPE™ block set allowed the determination of objective device parameters; the discharge coefficient and critical Reynolds number. The determination of these values was achieved utilizing the SIMULINK™ Parameter Estimation™ tool, experimental data, and a computational plant model of the experimental setup. With this information, an accurate computational model of the resistance device is presented for use in determining resistance settings in silico prior to implementation in the mock circulatory loop. Experimental in vitro trials verified the repeatability of the automated resistor performance by means of a staircase testing of piston position during several different continuous flow rates of a glycerin/water solution.

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Natural Scaffolds for Regenerative Medicine: Direct Determination of Detergents Entrapped in Decellularized Heart Valves

BioMed Research International ◽

10.1155/2017/9274135 ◽

2017 ◽

Vol 2017 ◽

pp. 1-9 ◽

Cited By ~ 6

Author(s):

Monica Dettin ◽

Annj Zamuner ◽

Filippo Naso ◽

Antonella Monteleone ◽

Michele Spina ◽

...

Keyword(s):

Heart Valve ◽

Heart Valves ◽

Anionic Surfactants ◽

Direct Determination ◽

Functional Expression ◽

Host Cells ◽

Resident Cell ◽

Different Types ◽

Cell Components

The increasing urgency for replacement of pathological heart valves is a major stimulus for research on alternatives to glutaraldehyde-treated grafts. New xenogeneic acellular heart valve substitutes that can be repopulated by host cells are currently under investigation. Anionic surfactants, including bile acids, have been widely used to eliminate the resident cell components chiefly responsible for the immunogenicity of the tissue, even if detergent toxicity might present limitations to the survival and/or functional expression of the repopulating cells. To date, the determination of residual detergent has been carried out almost exclusively on the washings following cell removal procedures. Here, a novel HPLC-based procedure is proposed for the direct quantification of detergent (cholate, deoxycholate, and taurodeoxycholate) residues entrapped in the scaffold of decellularized porcine aortic and pulmonary valves. The method was demonstrated to be sensitive, reproducible, and extendable to different types of detergent. This assessment also revealed that cell-depleted heart valve scaffolds prepared according to procedures currently considered for clinical use might contain significant amount of surfactant.

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The expression level of cytokine genes in the cases of native heart valves in infectious endocarditis

Biomeditsinskaya Khimiya ◽

10.18097/pbmc20206605406 ◽

2020 ◽

Vol 66 (5) ◽

pp. 406-410

Author(s):

M.Yu. Sinitsky ◽

A.V. Tsepokina ◽

M.A. Asanov ◽

Ya.V. Kazachek ◽

A.V. Evtushenko ◽

...

Keyword(s):

Gene Expression ◽

Heart Valves ◽

Surgical Correction ◽

Expression Level ◽

Infectious Endocarditis ◽

Cytokine Gene Expression ◽

Pronounced Increase ◽

Acquired Heart Disease ◽

Infectious Etiology

The expression level of IL1B, IL6, IL8, IL10, IL12A, IL12B, IL18, IL23, IL33, CCL2, and IL1RL1 has been investigated using biopsies of native mitral, aortic, and tricuspid valves obtained during surgical correction of acquired defect from 25 patients with infectious endocarditis. Biopsies of native mitral and aortic valve cusps from 12 patients who underwent surgical correction of acquired heart disease of non-infectious etiology were used as control. We used quantitative PCR with fluorescent dye SYBR Green for determination of the cytokine gene expression level. This study revealed that genes could be subdivided into three groups: (i) genes with increased expression (IL1B, IL6, and IL8); (ii) genes with reduced expression (IL33 and IL1RL1); (iii) genes with unchanged expression (IL12A, IL18, IL23, and CCL2). The IL8 gene expression was characterized by the most pronounced increase (9.83 times versus control), while the IL1RL1 gene demonstrated the most pronounced decrease in its expression (4.17 times). Expression of IL10 and IL12B genes was negligible in all samples.

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