subject:(Heart valves)

University of Toronto

1. Syed, Ishba Mughis. CLINICAL CHARACTERISTICS AND OUTCOMES IN PATIENTS WITH INFECTIVE ENDOCARDITIS (IE).

Degree: 2018, University of Toronto

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Infective endocarditis (IE) is a serious medical condition with significant morbidity and mortality. We sought to determine the clinical characteristics, microbiological profile and long-term outcome… (more)

Subjects/Keywords: Heart valves; Infection; Microorganisms; Mortality; 0564

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APA (6^th Edition):

Syed, I. M. (2018). CLINICAL CHARACTERISTICS AND OUTCOMES IN PATIENTS WITH INFECTIVE ENDOCARDITIS (IE). (Masters Thesis). University of Toronto. Retrieved from http://hdl.handle.net/1807/91603

Chicago Manual of Style (16^th Edition):

Syed, Ishba Mughis. “CLINICAL CHARACTERISTICS AND OUTCOMES IN PATIENTS WITH INFECTIVE ENDOCARDITIS (IE).” 2018. Masters Thesis, University of Toronto. Accessed April 11, 2021. http://hdl.handle.net/1807/91603.

MLA Handbook (7^th Edition):

Syed, Ishba Mughis. “CLINICAL CHARACTERISTICS AND OUTCOMES IN PATIENTS WITH INFECTIVE ENDOCARDITIS (IE).” 2018. Web. 11 Apr 2021.

Vancouver:

Syed IM. CLINICAL CHARACTERISTICS AND OUTCOMES IN PATIENTS WITH INFECTIVE ENDOCARDITIS (IE). [Internet] [Masters thesis]. University of Toronto; 2018. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1807/91603.

Council of Science Editors:

Syed IM. CLINICAL CHARACTERISTICS AND OUTCOMES IN PATIENTS WITH INFECTIVE ENDOCARDITIS (IE). [Masters Thesis]. University of Toronto; 2018. Available from: http://hdl.handle.net/1807/91603

University of Miami

2. Benny Klimek, Margaret E. Molecular Mechanisms of Heart Valve and Skeletal Muscle Development and Disease.

Degree: PhD, Molecular Cell and Developmental Biology (Medicine), 2014, University of Miami

URL: https://scholarlyrepository.miami.edu/oa_dissertations/1515

► Heart valves function to provide unidirectional blood flow during each cardiac cycle. The development of the heart valves from embryonic stages is a highly regulated… (more)

▼ Heart valves function to provide unidirectional blood flow during each cardiac cycle. The development of the heart valves from embryonic stages is a highly regulated process involving many signaling pathways in order to provide the proper extracellular matrix components in the trilaminar structure. When these processes are dysregulated, disease can persist in the valves. Here we examined additional levels of regulation in the heart valves at the level of miRNAs and phosphate homeostasis. There are many studies examining miRNA regulation in the heart, however, there is little knowledge about which miRNAs are expressed in the heart valves during development, maturation, homeostasis and disease. To address this gap and determine miRNA regulators of valve development and disease, RNA was extracted from mouse atrioventricular (AV) heart valves at mE11.5 (endocardial cushion), mE15.5 (remodeling), postnatal (maturing), and 4 months (4m) of age (maintained). The mechanism of miR-101 binding to the 3’UTR of Sox9, a SRY transcription factor required for proper valve development, was analyzed and the results suggest Sox9 may be regulated in the valves by miR-101 during development. In addition to the miRNA valve studies, although elevated FGF23 and phosphate serum levels have been demonstrated to be associated with vascular calcification in patients with chronic kidney disease (CKD), the direct effect on the heart valves remains unknown. Here we show evidence for phosphate, but not FGF23 promoting calcification in heart valve explants, valve interstitial cells and in mouse aortic smooth muscle cells. Sodium phosphate (NaPh) Co-transporters are required for this calcification and their expression is altered by phosphate and FGF23. Lastly, the data presented here also shows a mechanism by which skeletal muscle wasting or cachexia can be prevented in mouse models of cancer cachexia. These studies specifically look at inhibiting myostatin-family ligands in order to protect skeletal muscles from cancer induced wasting. Taken together, these studies provide evidence as to examine both heart valve and skeletal muscle signaling pathways further in order to understand the developmental processes that have gone awry in diseases associated with these tissues. (Revised 7/2014 CREC) Advisors/Committee Members: Christian Faul, Carlos Moraes, Alessia Fornoni, Steven Lipshultz, Nevis Fregien.

Subjects/Keywords: heart valves; miRNAs; calcification; phosphate; myostatin; cachexia

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APA (6^th Edition):

Benny Klimek, M. E. (2014). Molecular Mechanisms of Heart Valve and Skeletal Muscle Development and Disease. (Doctoral Dissertation). University of Miami. Retrieved from https://scholarlyrepository.miami.edu/oa_dissertations/1515

Chicago Manual of Style (16^th Edition):

Benny Klimek, Margaret E. “Molecular Mechanisms of Heart Valve and Skeletal Muscle Development and Disease.” 2014. Doctoral Dissertation, University of Miami. Accessed April 11, 2021. https://scholarlyrepository.miami.edu/oa_dissertations/1515.

MLA Handbook (7^th Edition):

Benny Klimek, Margaret E. “Molecular Mechanisms of Heart Valve and Skeletal Muscle Development and Disease.” 2014. Web. 11 Apr 2021.

Vancouver:

Benny Klimek ME. Molecular Mechanisms of Heart Valve and Skeletal Muscle Development and Disease. [Internet] [Doctoral dissertation]. University of Miami; 2014. [cited 2021 Apr 11]. Available from: https://scholarlyrepository.miami.edu/oa_dissertations/1515.

Council of Science Editors:

Benny Klimek ME. Molecular Mechanisms of Heart Valve and Skeletal Muscle Development and Disease. [Doctoral Dissertation]. University of Miami; 2014. Available from: https://scholarlyrepository.miami.edu/oa_dissertations/1515

Rice University

3. Puperi, Daniel. Biomimetic heterogeneous scaffolds for a layered tissue engineered heart valve.

Degree: PhD, Engineering, 2016, Rice University

URL: http://hdl.handle.net/1911/96554

► This dissertation describes strategies that I have developed to introduce mechanical and biochemical heterogeneity into synthetic tissue engineering scaffolds for heart valves. For a tissue… (more)

▼ This dissertation describes strategies that I have developed to introduce mechanical and biochemical heterogeneity into synthetic tissue engineering scaffolds for heart valves. For a tissue engineered heart valve to work well, it must meet the mechanical demands of the natural heart valve and support healthy valve cell behavior. Natural heart valve leaflets have a heterogeneous structure with distinct layers that provide the valve with unique mechanical functions. My research focused on mimicking the mechanics and biochemical signaling of each layer so that the entire scaffold will function similar to the natural valve. Three specific strategies to add heterogeneity into tissue engineered heart valve scaffolds are described in this thesis. First, I designed an innovative method to direct the proper spatial arrangement of cell adhesive peptides in order to promote the correct organization of the two different cell types in the valve (valve endothelial cells and valve interstitial cells). Second, hyaluronan hydrogels were utilized as a mechanical and biochemical mimic of the middle, spongiosa layer of heart valves. Third, I learned how valve interstitial cells respond to synthetic fibrous structure in 3D culture by designing a composite scaffold made from poly(ethylene glycol) hydrogels and electrospun polyurethane fibers. The electrospun fibers were incorporated to give the valve scaffold the anisotropic, viscoelastic, and non-linear mechanical behavior similar to native valves, while the hydrogel material functioned as a cell-friendly substrate. These specific research projects provide methods and results that advance the heart valve tissue engineering field while having broad applicability to other tissue engineering applications, especially for tissues which have a layered structure and a stratified distribution of multiple cell types. The results of this research also lay the groundwork for constructing heart valve scaffolds for the purpose of in vitro disease modeling. A synthetic heart valve model based on this research would be more consistent than explant animal valves and could be used to study the initiation and progression of heart valve disease. Advisors/Committee Members: Grande-Allen, Jane (advisor).

Subjects/Keywords: heart valves; tissue engineering; biomimetic; bimaterials

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APA (6^th Edition):

Puperi, D. (2016). Biomimetic heterogeneous scaffolds for a layered tissue engineered heart valve. (Doctoral Dissertation). Rice University. Retrieved from http://hdl.handle.net/1911/96554

Chicago Manual of Style (16^th Edition):

Puperi, Daniel. “Biomimetic heterogeneous scaffolds for a layered tissue engineered heart valve.” 2016. Doctoral Dissertation, Rice University. Accessed April 11, 2021. http://hdl.handle.net/1911/96554.

MLA Handbook (7^th Edition):

Puperi, Daniel. “Biomimetic heterogeneous scaffolds for a layered tissue engineered heart valve.” 2016. Web. 11 Apr 2021.

Vancouver:

Puperi D. Biomimetic heterogeneous scaffolds for a layered tissue engineered heart valve. [Internet] [Doctoral dissertation]. Rice University; 2016. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1911/96554.

Council of Science Editors:

Puperi D. Biomimetic heterogeneous scaffolds for a layered tissue engineered heart valve. [Doctoral Dissertation]. Rice University; 2016. Available from: http://hdl.handle.net/1911/96554

Clemson University

4. Tripi, Daniel. STABILIZATION OF EXTRACELLULAR MATRIX COMPONENTS IN BIOPROSTHETIC HEART VALVES USING NEOMYCIN AND PENTAGALLOYL GLUCOSE ENHANCED CROSSLINKING.

Degree: MS, Bioengineering, 2012, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/1439

► Bioprosthetic heart valves (BHVs) fail within 12-15 years of implantation due to limited durability. This limits their application to elderly population. Younger patients with contraindications… (more)

▼ Bioprosthetic heart valves (BHVs) fail within 12-15 years of implantation due to limited durability. This limits their application to elderly population. Younger patients with contraindications for long-term anticoagulant therapy necessary for mechanical heart valves may also receive BHVs. Investigation into improving valve durability can lead to longer implant life, increased quality of life for patients receiving BHVs, and a broadened patient demographic. Current BHVs are chemically treated with glutaraldehyde (GLUT) to stabilize collagen via chemical crosslinking and to reduce tissue antigenicity. GLUT fails to adequately stabilize elastin and glycosaminoglycans (GAGs), essential extracellular matrix components for valve function and durability. Degradation of elastin also increases elastin-oriented calcification. Previous use of neomycin and carbodiimide crosslinking has improved GAG stability. Similarly, use of pentagalloyl glucose (PGG), a plant polyphenol, has previously improved elastin stability in aortic wall and abdominal aortic aneurysm. We have focused on long term GAG stability using neomycin and carbodiimide crosslinking to replace GLUT, and the use of neomycin and PGG along with GLUT to stabilize elastin. The first study shows improved long term GAG stability when tissue treated with neomycin and carbodiimide crosslinking is stored for ten months or implanted subdermally in rats for up to 15 weeks. The second study evaluated stabilization of all extracellular matrix components against enzymatic degradation in an in vivo model, mechanical properties, and calcification potential and extracellular matrix stability in a rat subdermal model. This study demonstrated a marked increase in extracellular matrix stability when compared to GLUT control. Further, the changes we saw to mechanical properties can be attributed to specific crosslinking modalities. Neomycin, PGG and GLUT crosslinked tissue also demonstrated increased calcification potential in a rat subdermal model when compared to GLUT controls. In these studies we present two viable heart valve fixation techniques. One replaces GLUT with carbodiimide based chemistry, to stabilize GAGs and remove negative effects caused by GLUT. The other adds neomycin and PGG to GLUT to stabilize elastin and GAGs in bioprosthetic heart valve leaflets. By stabilizing these components, in vivo tissue and valve mechanics may improve, accompanied by an increase in valve durability. Advisors/Committee Members: Vyavahare, Naren R, LaBerge , Marine, Nagatomi , Jiro.

Subjects/Keywords: Bioprosthetic heart valves; Elastin; Glycosaminoglycans; Neomycin; Pentagalloyl glucose; Tissue heart valves; Biomedical Engineering and Bioengineering

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APA (6^th Edition):

Tripi, D. (2012). STABILIZATION OF EXTRACELLULAR MATRIX COMPONENTS IN BIOPROSTHETIC HEART VALVES USING NEOMYCIN AND PENTAGALLOYL GLUCOSE ENHANCED CROSSLINKING. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/1439

Chicago Manual of Style (16^th Edition):

Tripi, Daniel. “STABILIZATION OF EXTRACELLULAR MATRIX COMPONENTS IN BIOPROSTHETIC HEART VALVES USING NEOMYCIN AND PENTAGALLOYL GLUCOSE ENHANCED CROSSLINKING.” 2012. Masters Thesis, Clemson University. Accessed April 11, 2021. https://tigerprints.clemson.edu/all_theses/1439.

MLA Handbook (7^th Edition):

Tripi, Daniel. “STABILIZATION OF EXTRACELLULAR MATRIX COMPONENTS IN BIOPROSTHETIC HEART VALVES USING NEOMYCIN AND PENTAGALLOYL GLUCOSE ENHANCED CROSSLINKING.” 2012. Web. 11 Apr 2021.

Vancouver:

Tripi D. STABILIZATION OF EXTRACELLULAR MATRIX COMPONENTS IN BIOPROSTHETIC HEART VALVES USING NEOMYCIN AND PENTAGALLOYL GLUCOSE ENHANCED CROSSLINKING. [Internet] [Masters thesis]. Clemson University; 2012. [cited 2021 Apr 11]. Available from: https://tigerprints.clemson.edu/all_theses/1439.

Council of Science Editors:

Tripi D. STABILIZATION OF EXTRACELLULAR MATRIX COMPONENTS IN BIOPROSTHETIC HEART VALVES USING NEOMYCIN AND PENTAGALLOYL GLUCOSE ENHANCED CROSSLINKING. [Masters Thesis]. Clemson University; 2012. Available from: https://tigerprints.clemson.edu/all_theses/1439

Michigan State University

5. Nichols, James Beverly. Testing of RPMI-1640 as a nutrient medium for fresh semilunar valve storage.

Degree: MS, Department of Veterinary Surgery and Medicine, 1979, Michigan State University

URL: http://etd.lib.msu.edu/islandora/object/etd:42171

Subjects/Keywords: Heart valves; Heart – Preservation

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APA (6^th Edition):

Nichols, J. B. (1979). Testing of RPMI-1640 as a nutrient medium for fresh semilunar valve storage. (Masters Thesis). Michigan State University. Retrieved from http://etd.lib.msu.edu/islandora/object/etd:42171

Chicago Manual of Style (16^th Edition):

Nichols, James Beverly. “Testing of RPMI-1640 as a nutrient medium for fresh semilunar valve storage.” 1979. Masters Thesis, Michigan State University. Accessed April 11, 2021. http://etd.lib.msu.edu/islandora/object/etd:42171.

MLA Handbook (7^th Edition):

Nichols, James Beverly. “Testing of RPMI-1640 as a nutrient medium for fresh semilunar valve storage.” 1979. Web. 11 Apr 2021.

Vancouver:

Nichols JB. Testing of RPMI-1640 as a nutrient medium for fresh semilunar valve storage. [Internet] [Masters thesis]. Michigan State University; 1979. [cited 2021 Apr 11]. Available from: http://etd.lib.msu.edu/islandora/object/etd:42171.

Council of Science Editors:

Nichols JB. Testing of RPMI-1640 as a nutrient medium for fresh semilunar valve storage. [Masters Thesis]. Michigan State University; 1979. Available from: http://etd.lib.msu.edu/islandora/object/etd:42171

East Carolina University

6. Woodrow, Lawrence Kevin. A Biopsychosocial Examination of Transcatheter Aortic Valve Replacement Health Outcomes.

Degree: PhD, Psychology: Clinical Psychology, 2015, East Carolina University

URL: http://hdl.handle.net/10342/4984

► Cardiovascular disease (CVD) is the leading cause of death in the world accounting for 17.3 million deaths annually. Transcatheter aortic valve replacement (TAVR) was developed… (more)

Subjects/Keywords: Psychology; Anxiety; Dyspnea; Transcatheter aortic valve replacement; Heart valves – Diseases – Patients – Attitudes; Heart valves – Surgery; Quality of life

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APA (6^th Edition):

Woodrow, L. K. (2015). A Biopsychosocial Examination of Transcatheter Aortic Valve Replacement Health Outcomes. (Doctoral Dissertation). East Carolina University. Retrieved from http://hdl.handle.net/10342/4984

Chicago Manual of Style (16^th Edition):

Woodrow, Lawrence Kevin. “A Biopsychosocial Examination of Transcatheter Aortic Valve Replacement Health Outcomes.” 2015. Doctoral Dissertation, East Carolina University. Accessed April 11, 2021. http://hdl.handle.net/10342/4984.

MLA Handbook (7^th Edition):

Woodrow, Lawrence Kevin. “A Biopsychosocial Examination of Transcatheter Aortic Valve Replacement Health Outcomes.” 2015. Web. 11 Apr 2021.

Vancouver:

Woodrow LK. A Biopsychosocial Examination of Transcatheter Aortic Valve Replacement Health Outcomes. [Internet] [Doctoral dissertation]. East Carolina University; 2015. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10342/4984.

Council of Science Editors:

Woodrow LK. A Biopsychosocial Examination of Transcatheter Aortic Valve Replacement Health Outcomes. [Doctoral Dissertation]. East Carolina University; 2015. Available from: http://hdl.handle.net/10342/4984

Durban University of Technology

7. Gojo, Mawande Khayalethu Edson. Investigation of acute systemic inflammatory response and myocardial injury after cardiac surgery in patients infected with human immunodeficiency virus.

Degree: 2016, Durban University of Technology

URL: http://hdl.handle.net/10321/2577

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Submitted in fulfillment of the requirements for the degree of Masters of Health Sciences in Clinical Technology, Durban University of Technology, Durban, South Africa, 2016.… (more)

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Submitted in fulfillment of the requirements for the degree of Masters of Health Sciences in Clinical Technology, Durban University of Technology, Durban, South Africa, 2016.

Introduction: The immediate post-cardiopulmonary bypass (CPB) immune responses and organ injuries in immune- compromised patients remain poorly documented. We conducted a prospective clinical study to determine whether or not human immunodeficiency virus (HIV) seropositive patients generate higher acute systemic inflammatory response and suffer greater myocardial injury, compared to HIV seronegative patients. Methodology: Sixty-one consecutive patients i.e. Thirty HIV seropositive patients and Thirty-one seronegative, undergoing elective cardiac valve(s) replacement were enrolled, over a period of nine months from a single center hospital, after informed consent was acquired. The C-reactive protein (CRP) and Erythrocyte sedimentation rate (ESR) were used as biomarkers of acute inflammatory response, and cardiac troponin I (cTnI) as a biomarker for measuring postoperative myocardial injury. Single tests were measured preoperatively and postoperatively, in both groups, and these were compared and correlated to perioperative events and CPB parameters. Results: The mean age group was similar between the HIV seropositive and negative group (37.8 and 37.1 years, respectively). Preoperatively both groups had relatively equal CRP levels (p=0.388), ESR levels (p=0.817) and cTnI (p=0.489). The CPB events and durations were significantly different between the two groups, CPB duration (p=0.021). Other CPB events include, clamp aortic duration (p=0.026), CPB blood transfusion (p=0.013), CPB total urine output (p=0.035) and CPB peak lactate (p=0.040). Postoperatively we observed significant increased biomarkers level in both groups, with no significant difference between the groups: mean CRP (p=0.115), mean ESR (p=0.214) and cTnI (p=0.363). We observed a significant negative correlation between the mean change in CRP levels and mechanical ventilation (r=- 0.548, p=0.002) in the seropositive group, but not in the uninfected group (r=0.025, p=0.893). The correlation between the difference in CRP and ICU stay was not significant between in both group (r=-0.231, p=0.229 and r=0.25, p=0.975, respectively). A significant positive correlation between postoperative cTnI and the inotropic support duration (r=0.384, p=0.040) was seen in the seropositive groups, but not in the negative group (r=0.092, p=0.622). Furthermore we observed a significant drop in CD4 cells postoperatively (p=<0.001) in the HIV seropositive group. Antiretroviral treatment appeared to influence the degree of change in CD4 cells postoperatively. Conclusion: We conclude that HIV positive patients’ postoperative reactions to cardiac surgery supported by CPB are similar to those of HIV seronegetive patients. We further report non-paralleling correlations between the biomarkers and perioperative events; however these do not seem to affect the overall outcomes between the two…

Advisors/Committee Members: Prakaschandra, Rosaley.

Subjects/Keywords: Cardiopulmonary bypass; Inflammation; HIV-positive persons; Postoperative care; Heart valves – Surgery

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APA (6^th Edition):

Gojo, M. K. E. (2016). Investigation of acute systemic inflammatory response and myocardial injury after cardiac surgery in patients infected with human immunodeficiency virus. (Thesis). Durban University of Technology. Retrieved from http://hdl.handle.net/10321/2577

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Gojo, Mawande Khayalethu Edson. “Investigation of acute systemic inflammatory response and myocardial injury after cardiac surgery in patients infected with human immunodeficiency virus.” 2016. Thesis, Durban University of Technology. Accessed April 11, 2021. http://hdl.handle.net/10321/2577.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Gojo, Mawande Khayalethu Edson. “Investigation of acute systemic inflammatory response and myocardial injury after cardiac surgery in patients infected with human immunodeficiency virus.” 2016. Web. 11 Apr 2021.

Vancouver:

Gojo MKE. Investigation of acute systemic inflammatory response and myocardial injury after cardiac surgery in patients infected with human immunodeficiency virus. [Internet] [Thesis]. Durban University of Technology; 2016. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10321/2577.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Gojo MKE. Investigation of acute systemic inflammatory response and myocardial injury after cardiac surgery in patients infected with human immunodeficiency virus. [Thesis]. Durban University of Technology; 2016. Available from: http://hdl.handle.net/10321/2577

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Stellenbosch University

8. Kemp, Iain Henry. Development,testing and fluid interaction simulation of a bioprosthetic valve for transcatheter aortic valve implantation.

Degree: MScEng, Mechanical and Mechatronic Engineering, 2012, Stellenbosch University

URL: http://hdl.handle.net/10019.1/71710

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ENGLISH ABSTRACT: Bioprosthetic heart valves (BHVs) for transcatheter aortic valve implantation (TAVI) have been rapidly developing over the last decade since the first valve replacement… (more)

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ENGLISH ABSTRACT: Bioprosthetic heart valves (BHVs) for transcatheter aortic valve implantation (TAVI) have been rapidly developing over the last decade since the first valve replacement using the TAVI technique. TAVI is a minimally invasive valve replacement procedure offering lifesaving treatment to patients who are denied open heart surgery. The biomedical engineering research group at Stellenbosch University designed a 19 mm balloon expandable BHV for TAVI in 2007/8 for testing in animal trials. In the current study the valve was enlarged to 23 mm and 26 mm diameters. A finite element analysis was performed to aid in the design of the stents. New stencils were designed and manufactured for the leaflets using Thubrikar‟s equations as a guide. The 23 mm valve was manufactured and successfully implanted into two sheep. Fluid structure interaction (FSI) simulations constitute a large portion of this thesis and are being recognized as an important tool in the design of BHVs. Furthermore, they provide insight into the interaction of the blood with the valve, the leaflet dynamics and valve hemodynamic performance. The complex material properties, pulsating flow, large deformations and coupling of the fluid and the physical structure make this one of the most complicated and difficult research areas within the body. The FSI simulations, of the current valve design, were performed using a commercial programme called MSC.Dytran. A validation study was performed using data collected from a cardiac pulse duplicator. The FSI model was validated using leaflet dynamics visualisation and transvalvular pressure gradient comparison. Further comparison studies were performed to determine the material model to be used and the effect of leaflet free edge length and valve diameter on valve performance. The results from the validation study correlated well, considering the limitations that were experienced. However, further research is required to achieve a thorough validation. The comparative studies indicated that the linear isotropic material model was the most stable material model which could be used to simulate the leaflet behaviour. The free edge length of the leaflet affects the leaflet dynamics but does not greatly hinder its performance. The hemodynamic performance of the valve improves with an increase in diameter and the leaflet dynamics perform well considering the increased surface area and length. Many limitations in the software prevented more accurate material models and flow initiation to be implemented. These limitations significantly restricted the research and confidence in the results. Further investigation regarding the implementation of FSI simulations of a heart valve using the commercial software is recommended.

AFRIKAANSE OPSOMMING: Bio-prostetiese hartkleppe (Bioprosthetic Heart Valves - BHVs) wat gebruik word vir transkateter aortaklep-inplantings (Transcatheter Aortic Valve Implantation - TAVI) het geweldig vinnige ontwikkeling getoon in die afgelope tien jaar sedert die eerste klepvervanging wat…

Advisors/Committee Members: Scheffer, C., Blaine, D. C., Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering..

Subjects/Keywords: Mechanical engineering; Bioprosthetic heart valves; Valve hemodynamic performance.

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APA (6^th Edition):

Kemp, I. H. (2012). Development,testing and fluid interaction simulation of a bioprosthetic valve for transcatheter aortic valve implantation. (Masters Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/71710

Chicago Manual of Style (16^th Edition):

Kemp, Iain Henry. “Development,testing and fluid interaction simulation of a bioprosthetic valve for transcatheter aortic valve implantation.” 2012. Masters Thesis, Stellenbosch University. Accessed April 11, 2021. http://hdl.handle.net/10019.1/71710.

MLA Handbook (7^th Edition):

Kemp, Iain Henry. “Development,testing and fluid interaction simulation of a bioprosthetic valve for transcatheter aortic valve implantation.” 2012. Web. 11 Apr 2021.

Vancouver:

Kemp IH. Development,testing and fluid interaction simulation of a bioprosthetic valve for transcatheter aortic valve implantation. [Internet] [Masters thesis]. Stellenbosch University; 2012. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10019.1/71710.

Council of Science Editors:

Kemp IH. Development,testing and fluid interaction simulation of a bioprosthetic valve for transcatheter aortic valve implantation. [Masters Thesis]. Stellenbosch University; 2012. Available from: http://hdl.handle.net/10019.1/71710

9. Jaffer, Iqbal H. Application of the Direct Oral Anticoagulants to Thromboprophylaxis of Mechanical Heart Valves.

Degree: PhD, 2017, McMaster University

URL: http://hdl.handle.net/11375/21235

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Patients with valvular pathology who require heart valve replacement surgery are faced with the option between a bioprosthetic heart valve (BHV) or a mechanical heart… (more)

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Patients with valvular pathology who require heart valve replacement surgery are faced with the option between a bioprosthetic heart valve (BHV) or a mechanical heart valve (MHV). BHVs have a limited lifespan and are prone to structural degeneration. In contrast, MHVs are free from structural deterioration, but necessitate lifelong anticoagulation due to a more robust activation of coagulation. This is usually achieved in the outpatient setting with the use of vitamin K antagonists (VKAs), such as warfarin. Due to the cumbersomeness of managing warfarin with regular monitoring and its numerous food- and drug-drug interactions, other oral anticoagulants were sought. Within the last decade, the advent of the direct oral anticoagulants (DOACs) has largely supplanted warfarin and other VKAs for numerous indications, including stroke prevention in atrial fibrillation and prevention and treatment of venous thromboembolism. When evaluated in a clinical trial in patients with MHVs however, use of the thrombin-directed DOAC, dabigatran, led to an increase in both bleeding and clotting; prompting a halt to the study and a black box warning against the use of dabigatran and other DOACs in patients with MHVs. The cause of this failure at the time was not understood and prompted the investigations detailed in this thesis. The work described within this thesis sought primarily to understand why dabigatran failed to adequately provide thrombo-protection for patients with MHVs. Firstly, the mechanism of thrombin generation on MHVs was identified as being initiated and propagated through the contact and intrinsic pathways, respectively. Within this same work, a mechanism for the failure of dabigatran and the efficacy of warfarin was presented. It was shown that dabigatran concentrations of greater than 250ng/mL were required to suppress thrombin generation, whereas the same effect could be achieved with warfarin at an INR of 1.5 or greater. Secondly, the effect of the other DOACs, rivaroxaban and apixaban, on MHV-induced thrombin generation was assessed, and we showed that individually, these two DOACs were unable to suppress thrombin generation within clinically-relevant dosing regimens. We also evaluated a combination of dabigatran and rivaroxaban to determine whether the combination would be superior to either agent alone at suppressing MHV-induced thrombin generation. Lastly, the capacity of two assays – the ecarin chromogenic assay and the dilute thrombin time – to detect both on treatment and low levels of dabigatran is presented as a tool for clinicians to determine whether patients taking dabigatran can safely undergo procedures or whether they necessitate rapid reversal in emergent situations.

Thesis

Doctor of Philosophy (PhD)

Advisors/Committee Members: Weitz, Jeffrey, Medical Sciences (Blood and Cardiovascular).

Subjects/Keywords: Anticoagulation; Heart Valves; Coagulation

…52 1.9 Heart Valves… …mechanical heart valves MI - myocardial infraction NO = nitric oxide PAI-1 = plasminogen activator… …63 Chapter 3: Dabigatran is Less Effective Than Warfarin at Attenuating Mechanical Heart… …alone to suppress mechanical heart valve-induced thrombin generation ................... 96… …53 Figure 10: Mechanical heart valve components…

13 more images…

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APA (6^th Edition):

Jaffer, I. H. (2017). Application of the Direct Oral Anticoagulants to Thromboprophylaxis of Mechanical Heart Valves. (Doctoral Dissertation). McMaster University. Retrieved from http://hdl.handle.net/11375/21235

Chicago Manual of Style (16^th Edition):

Jaffer, Iqbal H. “Application of the Direct Oral Anticoagulants to Thromboprophylaxis of Mechanical Heart Valves.” 2017. Doctoral Dissertation, McMaster University. Accessed April 11, 2021. http://hdl.handle.net/11375/21235.

MLA Handbook (7^th Edition):

Jaffer, Iqbal H. “Application of the Direct Oral Anticoagulants to Thromboprophylaxis of Mechanical Heart Valves.” 2017. Web. 11 Apr 2021.

Vancouver:

Jaffer IH. Application of the Direct Oral Anticoagulants to Thromboprophylaxis of Mechanical Heart Valves. [Internet] [Doctoral dissertation]. McMaster University; 2017. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/11375/21235.

Council of Science Editors:

Jaffer IH. Application of the Direct Oral Anticoagulants to Thromboprophylaxis of Mechanical Heart Valves. [Doctoral Dissertation]. McMaster University; 2017. Available from: http://hdl.handle.net/11375/21235

University of Cape Town

10. Wheatley, David John. Fibroblast viability in the allograft heart valve leaflet.

Degree: Image, Fibroblasts, 1976, University of Cape Town

URL: http://hdl.handle.net/11427/24949

Subjects/Keywords: Heart Valves - transplantation; Transplantation, Homologous

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Wheatley, D. J. (1976). Fibroblast viability in the allograft heart valve leaflet. (Thesis). University of Cape Town. Retrieved from http://hdl.handle.net/11427/24949

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Wheatley, David John. “Fibroblast viability in the allograft heart valve leaflet.” 1976. Thesis, University of Cape Town. Accessed April 11, 2021. http://hdl.handle.net/11427/24949.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Wheatley, David John. “Fibroblast viability in the allograft heart valve leaflet.” 1976. Web. 11 Apr 2021.

Vancouver:

Wheatley DJ. Fibroblast viability in the allograft heart valve leaflet. [Internet] [Thesis]. University of Cape Town; 1976. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/11427/24949.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Wheatley DJ. Fibroblast viability in the allograft heart valve leaflet. [Thesis]. University of Cape Town; 1976. Available from: http://hdl.handle.net/11427/24949

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Manitoba

11. Ambrose, Emma. Characterization of autologous cell sources for alternatives to aortic valvular interstitial cells in tissue engineered heart valves.

Degree: Physiology and Pathophysiology, 2016, University of Manitoba

URL: http://hdl.handle.net/1993/31804

► The gold standard treatment for patients with AVD is surgical replacement of the aortic valve with either mechanical or fixed tissue prostheses. These implants have… (more)

Subjects/Keywords: Tissue engineered heart valves; Aortic valve disease; Aortic valve

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APA (6^th Edition):

Ambrose, E. (2016). Characterization of autologous cell sources for alternatives to aortic valvular interstitial cells in tissue engineered heart valves. (Masters Thesis). University of Manitoba. Retrieved from http://hdl.handle.net/1993/31804

Chicago Manual of Style (16^th Edition):

Ambrose, Emma. “Characterization of autologous cell sources for alternatives to aortic valvular interstitial cells in tissue engineered heart valves.” 2016. Masters Thesis, University of Manitoba. Accessed April 11, 2021. http://hdl.handle.net/1993/31804.

MLA Handbook (7^th Edition):

Ambrose, Emma. “Characterization of autologous cell sources for alternatives to aortic valvular interstitial cells in tissue engineered heart valves.” 2016. Web. 11 Apr 2021.

Vancouver:

Ambrose E. Characterization of autologous cell sources for alternatives to aortic valvular interstitial cells in tissue engineered heart valves. [Internet] [Masters thesis]. University of Manitoba; 2016. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1993/31804.

Council of Science Editors:

Ambrose E. Characterization of autologous cell sources for alternatives to aortic valvular interstitial cells in tissue engineered heart valves. [Masters Thesis]. University of Manitoba; 2016. Available from: http://hdl.handle.net/1993/31804

University of Miami

12. Peacock, Jacqueline D. The Role of Sox9 in Heart Valve Development and Disease.

Degree: PhD, Molecular and Cellular Pharmacology (Medicine), 2011, University of Miami

URL: https://scholarlyrepository.miami.edu/oa_dissertations/543

► Heart valve structures open and close during the cardiac cycle to provide unidirectional blood flow through the heart, critical for efficient cardiovascular function. Valve dysfunction… (more)

▼ Heart valve structures open and close during the cardiac cycle to provide unidirectional blood flow through the heart, critical for efficient cardiovascular function. Valve dysfunction results in either incomplete opening or incomplete closure of the valve. Both types of valve dysfunction decrease efficiency of blood flow, increasing the load on the myocardium and leading to secondary heart disease such as pathological hypertrophy and heart failure. There are currently no effective treatments to prevent or slow the progression of valve disease, and there are no pharmacological treatments for advanced valve disease. Although most valve disease is associated with aging, increasing evidence suggests that valve disease often has origins in development. Congenital valvuloseptal defects affect many newborns, ranging from life-threatening malformations requiring immediate repair to more subtle, often undiagnosed defects that increase susceptibility to valve disease later in life. Therefore, an improved understanding of the mechanisms of heart valve formation and maintenance of adult valves may serve as an important step in improving valve disease treatment options. In this work, the mechanisms of normal valve development and the role of Sox9 in developing and mature valves are further studied. The temporal and spatial expression of extracellular matrix genes and proteins are examined throughout normal murine valve development. Sox9 function in the processes of valve development and valve maintenance is examined using mouse models of conditional Sox9 loss-of-function. Heart valve phenotypes in mice with reduced Sox9 function are examined throughout development and in adult mice with resultant calcific valve disease. The possible causative mechanisms of calcific valve disease in mice with reduced Sox9 function are further investigated by identification of novel possible targets of Sox9 transcriptional regulation. Together these studies improve our understanding of heart valve development, characterize a model of heart valve calcification with genetic etiology, and identify and characterize novel targets of Sox9. Advisors/Committee Members: Joy Lincoln, Nanette H. Bishopric, Steven E. Lipshultz, Mary Lou King, Lidia Kos.

Subjects/Keywords: Sox9; transcription factor; heart valves; development; valve calcification

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Peacock, J. D. (2011). The Role of Sox9 in Heart Valve Development and Disease. (Doctoral Dissertation). University of Miami. Retrieved from https://scholarlyrepository.miami.edu/oa_dissertations/543

Chicago Manual of Style (16^th Edition):

Peacock, Jacqueline D. “The Role of Sox9 in Heart Valve Development and Disease.” 2011. Doctoral Dissertation, University of Miami. Accessed April 11, 2021. https://scholarlyrepository.miami.edu/oa_dissertations/543.

MLA Handbook (7^th Edition):

Peacock, Jacqueline D. “The Role of Sox9 in Heart Valve Development and Disease.” 2011. Web. 11 Apr 2021.

Vancouver:

Peacock JD. The Role of Sox9 in Heart Valve Development and Disease. [Internet] [Doctoral dissertation]. University of Miami; 2011. [cited 2021 Apr 11]. Available from: https://scholarlyrepository.miami.edu/oa_dissertations/543.

Council of Science Editors:

Peacock JD. The Role of Sox9 in Heart Valve Development and Disease. [Doctoral Dissertation]. University of Miami; 2011. Available from: https://scholarlyrepository.miami.edu/oa_dissertations/543

University of Adelaide

13. Hearn, Trevor Charles. Mathematical studies of atrio-ventricular valve vibration / by Trevor C. Hearn.

Degree: 1980, University of Adelaide

URL: http://hdl.handle.net/2440/20182

Subjects/Keywords: Heart-valves Mathematical models.

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APA (6^th Edition):

Hearn, T. C. (1980). Mathematical studies of atrio-ventricular valve vibration / by Trevor C. Hearn. (Thesis). University of Adelaide. Retrieved from http://hdl.handle.net/2440/20182

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Hearn, Trevor Charles. “Mathematical studies of atrio-ventricular valve vibration / by Trevor C. Hearn.” 1980. Thesis, University of Adelaide. Accessed April 11, 2021. http://hdl.handle.net/2440/20182.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Hearn, Trevor Charles. “Mathematical studies of atrio-ventricular valve vibration / by Trevor C. Hearn.” 1980. Web. 11 Apr 2021.

Vancouver:

Hearn TC. Mathematical studies of atrio-ventricular valve vibration / by Trevor C. Hearn. [Internet] [Thesis]. University of Adelaide; 1980. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/2440/20182.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Hearn TC. Mathematical studies of atrio-ventricular valve vibration / by Trevor C. Hearn. [Thesis]. University of Adelaide; 1980. Available from: http://hdl.handle.net/2440/20182

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Cape Town

14. Kariv, Sarah. Haemorrhage and Other Complications in Pregnant Women on Anticoagulation for Mechanical Heart Valves; a Prospective Observational Cohort Study.

Degree: MMed, Medicine, 2019, University of Cape Town

URL: http://hdl.handle.net/11427/31685

► Objective: To document maternal and foetal morbidity and mortality in anticoagulated, pregnant patients with mechanical heart valves until 42 days postpartum. Methods: In a tertiary… (more)

Subjects/Keywords: warfarin; heparin, pregnancy; anticoagulation; mechanical heart valves; Africa

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APA (6^th Edition):

Kariv, S. (2019). Haemorrhage and Other Complications in Pregnant Women on Anticoagulation for Mechanical Heart Valves; a Prospective Observational Cohort Study. (Thesis). University of Cape Town. Retrieved from http://hdl.handle.net/11427/31685

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Kariv, Sarah. “Haemorrhage and Other Complications in Pregnant Women on Anticoagulation for Mechanical Heart Valves; a Prospective Observational Cohort Study.” 2019. Thesis, University of Cape Town. Accessed April 11, 2021. http://hdl.handle.net/11427/31685.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Kariv, Sarah. “Haemorrhage and Other Complications in Pregnant Women on Anticoagulation for Mechanical Heart Valves; a Prospective Observational Cohort Study.” 2019. Web. 11 Apr 2021.

Vancouver:

Kariv S. Haemorrhage and Other Complications in Pregnant Women on Anticoagulation for Mechanical Heart Valves; a Prospective Observational Cohort Study. [Internet] [Thesis]. University of Cape Town; 2019. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/11427/31685.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Kariv S. Haemorrhage and Other Complications in Pregnant Women on Anticoagulation for Mechanical Heart Valves; a Prospective Observational Cohort Study. [Thesis]. University of Cape Town; 2019. Available from: http://hdl.handle.net/11427/31685

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

15. Simon-Walker, Rachael. Hemocompatibility of hyaluronan enhanced linear low-density polyethylene for heart valve leaflet applications.

Degree: PhD, Bioengineering, 2018, Colorado State University

URL: http://hdl.handle.net/10217/193185

► Heart valve disease is a major concern in both developed countries with advanced ageing populations and undeveloped countries which experience a high incidence of rheumatism… (more)

Subjects/Keywords: heart valves; immune response; polymers; hemocompatibility; biomaterials; platelets

10 more images…

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APA (6^th Edition):

Simon-Walker, R. (2018). Hemocompatibility of hyaluronan enhanced linear low-density polyethylene for heart valve leaflet applications. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/193185

Chicago Manual of Style (16^th Edition):

Simon-Walker, Rachael. “Hemocompatibility of hyaluronan enhanced linear low-density polyethylene for heart valve leaflet applications.” 2018. Doctoral Dissertation, Colorado State University. Accessed April 11, 2021. http://hdl.handle.net/10217/193185.

MLA Handbook (7^th Edition):

Simon-Walker, Rachael. “Hemocompatibility of hyaluronan enhanced linear low-density polyethylene for heart valve leaflet applications.” 2018. Web. 11 Apr 2021.

Vancouver:

Simon-Walker R. Hemocompatibility of hyaluronan enhanced linear low-density polyethylene for heart valve leaflet applications. [Internet] [Doctoral dissertation]. Colorado State University; 2018. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10217/193185.

Council of Science Editors:

Simon-Walker R. Hemocompatibility of hyaluronan enhanced linear low-density polyethylene for heart valve leaflet applications. [Doctoral Dissertation]. Colorado State University; 2018. Available from: http://hdl.handle.net/10217/193185

16. Márcia Mayumi Omi Simbara. Fabricação e caracterização de um protótipo de arcabouço para engenharia tecidual de válvulas cardíacas.

Degree: 2019, University of São Paulo

URL: http://www.teses.usp.br/teses/disponiveis/98/98131/tde-17122019-153538/

►

Estima-se que, em 2050, o número de pacientes ao redor do mundo que precisarão de substituições valvares chegue a 850 mil por ano. As próteses… (more)

▼

Estima-se que, em 2050, o número de pacientes ao redor do mundo que precisarão de substituições valvares chegue a 850 mil por ano. As próteses atuais (mecânicas e biológicas) apresentam bons resultados, porém são incapazes de crescer com os pacientes. A engenharia tecidual aparece como promessa para resolução deste problema, pois visa à criação de um substituto vivo. O presente trabalho teve como objetivo fabricar e caracterizar um novo arcabouço polimérico biorreabsorvível para engenharia tecidual de valvas cardíacas, além de encontrar um processo de esterilização eficaz para viabilizar seu uso como dispositivo implantável. O arcabouço, inicialmente projetado para valvas semilunares, foi baseado no formato das próteses biológicas, sendo composto por um anel rígido, denominado stent (cujo formato foi otimizado através do método de otimização topológica) e três folhetos flexíveis. Os processos de fabricação e materiais escolhidos para a confecção do arcabouço foram: a manufatura aditiva em poli(ácido láctico) (PLA) para o stent, e a técnica de fiação por sopro em solução com poli(?-caprolactona) (PCL) para os folhetos. Primeiramente, foram fabricadas amostras, utilizando as mesmas técnicas e materiais mencionados, em formato simplificado (retangular). Estas foram submetidas a caracterizações químicas, mecânicas, morfológicas e de desempenho biológico. A esterilização por plasma de peróxido de hidrogênio foi então testada e validada, e as amostras estéreis foram caracterizadas da mesma maneira, para verificar se este processo causou alguma alteração. Posteriormente, um protótipo completo foi fabricado e seu desempenho hidrodinâmico foi avaliado. Os resultados mostraram que o processo de esterilização cumpriu seu propósito sem alterar as propriedades analisadas do arcabouço. O desempenho hidrodinâmico foi considerado satisfatório, dado que o arcabouço suportou pressões de até 120 mmHg por mais de 30 minutos, indicando assim que o design e os materiais escolhidos são adequados. Tais resultados indicam que o arcabouço pode, em breve, seguir para a cultura celular em biorreator, onde espera-se obter uma estrutura com organização tecidual semelhante à da valva nativa.

The annual number of patients requiring valve replacement surgeries worldwide is projected to reach 850,000 by the year 2050. While current prosthetic valves (mechanical and biological) offer good results, they are cannot grow with the patients. Tissue engineering represents a promising alternative to solve this problem, because it aims to create living substitutes. The present work aimed to fabricate and characterize a new bioresorbable polymer scaffold for heart valve tissue engineering, as well as to find an effective sterilization process to allow its use as an implantable device. The scaffold, initially intended for use as a semilunar valve, was based on the shape of biological valves, and was composed of a rigid ring, called stent (whose shape was optimized using the topological optimization method) and three flexible leaflets. The fabrication…

Advisors/Committee Members: Aron Jose Pazin de Andrade, Sonia Maria Malmonge, Magaly Arrais dos Santos, Everaldo Carlos Venancio.

Subjects/Keywords: Engenharia Tecidual; Materiais Biocompatíveis; Valvas Cardíacas; biomaterials; heart valves; tissue engineering

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APA (6^th Edition):

Simbara, M. M. O. (2019). Fabricação e caracterização de um protótipo de arcabouço para engenharia tecidual de válvulas cardíacas. (Doctoral Dissertation). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/98/98131/tde-17122019-153538/

Chicago Manual of Style (16^th Edition):

Simbara, Márcia Mayumi Omi. “Fabricação e caracterização de um protótipo de arcabouço para engenharia tecidual de válvulas cardíacas.” 2019. Doctoral Dissertation, University of São Paulo. Accessed April 11, 2021. http://www.teses.usp.br/teses/disponiveis/98/98131/tde-17122019-153538/.

MLA Handbook (7^th Edition):

Simbara, Márcia Mayumi Omi. “Fabricação e caracterização de um protótipo de arcabouço para engenharia tecidual de válvulas cardíacas.” 2019. Web. 11 Apr 2021.

Vancouver:

Simbara MMO. Fabricação e caracterização de um protótipo de arcabouço para engenharia tecidual de válvulas cardíacas. [Internet] [Doctoral dissertation]. University of São Paulo; 2019. [cited 2021 Apr 11]. Available from: http://www.teses.usp.br/teses/disponiveis/98/98131/tde-17122019-153538/.

Council of Science Editors:

Simbara MMO. Fabricação e caracterização de um protótipo de arcabouço para engenharia tecidual de válvulas cardíacas. [Doctoral Dissertation]. University of São Paulo; 2019. Available from: http://www.teses.usp.br/teses/disponiveis/98/98131/tde-17122019-153538/

University of Texas Southwestern Medical Center

17. Yu, Sangho. The Chemokine Receptor CXCR7 Functions in Endocardial-Derived Cells to Regulate Cardiac Valve Remodeling.

Degree: 2010, University of Texas Southwestern Medical Center

URL: http://hdl.handle.net/2152.5/918

► Cardiac disease is the number one killer in developed countries and congenital heart diseases are the most common birth defects worldwide. The heart supplies nutrients… (more)

▼ Cardiac disease is the number one killer in developed countries and congenital heart diseases are the most common birth defects worldwide. The heart supplies nutrients and oxygen to the entire body, therefore the proper development and function of the heart is essential for survival of an organism. During looping and maturation phases of heart development, proper separation of the outflow tract and chambers, and correct connection to the existing vascular system are critical to ensure unidirectional blood flow and supply of oxygenated blood to the rest of the body. Cardiac neural crest cells and endocardial cushions contribute significantly to these remodeling processes. Cardiac valves are fibrous tissues that separate atria from ventricles and ventricles from great vessels, and allow unidirectional blood flow through the heart. They are derived from specific sets of endocardial cells in the outflow tract and atrioventricular canal. Cardiac valvulogenesis is a highly ordered process and small perturbations in any of signaling pathways involved can result in fatal consequences. As a result, cardiac valve anomaly is one of the most common congenital heart diseases. CXCR7 is a chemokine receptor whose function in the heart is unknown. Unexpected cardiac phenotypes of Cxcr7 knockout mice prompted further investigation to elucidate its role during heart development. I speculated that CXCR7 functions during cardiac valve formation due to its high expression in cushion endocardial and mesenchymal cells, and the phenotype of Cxcr7 knockout mice at birth: cyanotic pups and enlarged hearts. Histological analysis of Cxcr7 knockout hearts at different developmental stages revealed that the aortic and pulmonary valves were thickened during late valve remodeling. This was due to unchecked proliferation of cushion mesenchymal cells as revealed by phospho-histone H3 staining. Increased proliferation was due to increased BMP signaling in the cardiac cushions even though direct interaction between CXCR7 and BMP signaling is unclear. Endothelial cell-specific deletion of Cxcr7 using Tie2-Cre resulted in hypertrophy of the heart in adult mice because of semilunar valve stenosis, confirming important function of CXCR7 in endocardial-derived cells. This study provides valuable insight into the mechanism controlling cardiac cushion mesenchymal cell proliferation and may contribute to better diagnosis, treatment, and prevention of cardiac valve defects in humans. Advisors/Committee Members: Srivastava, Deepak.

Subjects/Keywords: Receptors, CXCR; Heart Disease; Heart Valves

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APA (6^th Edition):

Yu, S. (2010). The Chemokine Receptor CXCR7 Functions in Endocardial-Derived Cells to Regulate Cardiac Valve Remodeling. (Thesis). University of Texas Southwestern Medical Center. Retrieved from http://hdl.handle.net/2152.5/918

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Yu, Sangho. “The Chemokine Receptor CXCR7 Functions in Endocardial-Derived Cells to Regulate Cardiac Valve Remodeling.” 2010. Thesis, University of Texas Southwestern Medical Center. Accessed April 11, 2021. http://hdl.handle.net/2152.5/918.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Yu, Sangho. “The Chemokine Receptor CXCR7 Functions in Endocardial-Derived Cells to Regulate Cardiac Valve Remodeling.” 2010. Web. 11 Apr 2021.

Vancouver:

Yu S. The Chemokine Receptor CXCR7 Functions in Endocardial-Derived Cells to Regulate Cardiac Valve Remodeling. [Internet] [Thesis]. University of Texas Southwestern Medical Center; 2010. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/2152.5/918.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Yu S. The Chemokine Receptor CXCR7 Functions in Endocardial-Derived Cells to Regulate Cardiac Valve Remodeling. [Thesis]. University of Texas Southwestern Medical Center; 2010. Available from: http://hdl.handle.net/2152.5/918

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Western Ontario

18. Liu, Yin. Role Of Nitric Oxide In Embryonic Heart Development And Adult Aortic Valve Disease.

Degree: 2014, University of Western Ontario

URL: https://ir.lib.uwo.ca/etd/2108

► Congenital heart disease (CHD) is the most common birth defect in infants. Identifying factors that are critical to embryonic heart development or CHDs in general… (more)

▼ Congenital heart disease (CHD) is the most common birth defect in infants. Identifying factors that are critical to embryonic heart development or CHDs in general could further our understanding of the disease and may lead to new strategies of its prevention and treatment. Endothelial nitric oxide synthase (NOS3/eNOS) is known for many important biological functions including vasodilation, vascular homeostasis and angiogenesis. Previous studies have shown that deficiency in NOS3 results in congenital septal defects, cardiac hypertrophy and postnatal heart failure. In addition, NOS3 is pivotal to morphogenesis of aortic valve and myocardial capillary development. The aim of my thesis was to investigate the role of NOS3 in the embryonic and adult heart. I discovered that NOS3 deficiency resulted in coronary artery hypoplasia in fetal mice and spontaneous myocardial infarction in postnatal hearts. Coronary artery diameters, vessel density and volume were significantly decreased in NOS3-/- mice at postnatal day 0. Lack of NOS3 also down-regulated the expression of Gata4, Wilms tumor-1, vascular endothelial growth factor, basic fibroblast growth factor and erythropoietin in the embryonic heart at E12.5, and inhibited migration of epicardial cells into the myocardium. In addition, my data show that the overall size and length of mitral and tricuspid valves were decreased in NOS3-/- compared with WT mice. Echocardiographic assessment showed significant regurgitation of mitral and tricuspid valves during systole in NOS3-/- mice. Immunostaining of Snail1 was performed in the embryonic heart. Snail1 positive and total mesenchymal cells in the AV cushion were decreased in NOS3-/- compared with WT mice at E10.5 and E12.5. Finally, in the adult aortic valves, NOS3 is important in inhibition of thrombosis formation. Deficiency in NOS3 leads to aortic valve thrombosis and calcification. At 12 months old, 72% (13/18) of NOS3-/- mice showed severe spontaneous aortic valve thrombosis compared with WT mice (0/12). Ex vivo culture of aortic valves showed that platelet aggregation and adhesion were significantly increased in NOS3-/- aortic valves compared with WT aortic valves. There was also a significant regurgitation of the aortic valve during systole in the NOS3-/- compared with WT mice. In addition, NOS3 deficiency resulted in significant aortic valve stenosis, calcification and fibrosis. In summary, these data suggest NOS3 plays a critical role in embryonic heart development and morphogenesis of coronary arteries and inhibits thrombosis formation in the adult aortic valves.

Subjects/Keywords: NOS3; heart development; aortic valves; coronary artery; atrioventricular valves; thrombosis; Cellular and Molecular Physiology; Developmental Biology; Molecular Genetics

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Liu, Y. (2014). Role Of Nitric Oxide In Embryonic Heart Development And Adult Aortic Valve Disease. (Thesis). University of Western Ontario. Retrieved from https://ir.lib.uwo.ca/etd/2108

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Liu, Yin. “Role Of Nitric Oxide In Embryonic Heart Development And Adult Aortic Valve Disease.” 2014. Thesis, University of Western Ontario. Accessed April 11, 2021. https://ir.lib.uwo.ca/etd/2108.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Liu, Yin. “Role Of Nitric Oxide In Embryonic Heart Development And Adult Aortic Valve Disease.” 2014. Web. 11 Apr 2021.

Vancouver:

Liu Y. Role Of Nitric Oxide In Embryonic Heart Development And Adult Aortic Valve Disease. [Internet] [Thesis]. University of Western Ontario; 2014. [cited 2021 Apr 11]. Available from: https://ir.lib.uwo.ca/etd/2108.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Liu Y. Role Of Nitric Oxide In Embryonic Heart Development And Adult Aortic Valve Disease. [Thesis]. University of Western Ontario; 2014. Available from: https://ir.lib.uwo.ca/etd/2108

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of KwaZulu-Natal

19. Chih-Yuan, Chen. A 10-year institutional review of surgery for structural valve dysfunction in the developing world.

Degree: 2017, University of KwaZulu-Natal

URL: https://researchspace.ukzn.ac.za/handle/10413/18495

► Background Prosthetic heart valves do not fulfil the requirements for an ideal valve, resulting in the development of prosthetic dysfunction or complications over time. Structural… (more)

▼ Background Prosthetic heart valves do not fulfil the requirements for an ideal valve, resulting in the development of prosthetic dysfunction or complications over time. Structural valve dysfunction may be influenced by multiple components which include patient’s factors, valve related factors and intraoperative factors. The inter-relation of these factors has a significant impact on morbidity and mortality associated with reoperative surgery for prosthetic valve dysfunction, particularly in a developing world where a large burden of communicable diseases together with lack of health care resources affect surgical outcome. In this study we examined the clinical records of the patients who underwent reoperative valve surgery to evaluate the clinical profile and factors that affect the surgical outcome after reoperation at a large tertiary referral center in a developing country. Objectives 1) To describe the demographic profile of patients with malfunctioning prosthetic heart valves and define their clinical presentation 2) To describe the clinical presentation of valve dysfunction 3) To determine the possible mechanisms of mechanical and bioprosthetic valve failure 4) To determine the factors affecting the immediate surgical outcomes in subjects undergoing redo cardiac prosthetic valve surgery. Materials and methods A retrospective analysis of the clinical, perioperative and follow-up data of patients who underwent redo cardiac valve surgery for structural valve dysfunction between January 2005 and December 2014 at Inkosi Albert Luthuli Central Hospital, Durban, South Africa was undertaken. Patients were identified using the Speedminer software program which is a Data Warehouse software package used to store data collected on the hospital Medicom database. The file of each of patient who underwent redo cardiac prosthetic valve replacement for structural valve dysfunction was accessed and data were extracted on age, gender, potential risk factors for valve thrombosis, symptomatology, investigations including International normalized Ratio (INR) status and follow up. All patients were evaluated preoperatively by the cardiologist and the cardiothoracic surgical team and submitted for either an elective or emergency valve replacement. Excluded from the study were those patients who underwent cardiothoracic surgery for nonvalvular reasons, i.e. coronary artery bypass surgery and congenital heart disease. Results During the ten year period (2005 to 2014) 2618 valve replacement operations were performed. During the same period 128 reoperations (4.9%) were performed in 113 patients (mean age 35.59 (SD±16.66) years). The majority of the patients were Black (72.6%) and female (75%). Fifteen patients (13.3%) were HIV infected and nine were pregnant. Acute dyspnoea (NYHA class III 34.37% and class IV 21.88%) was the presenting feature in 72 patients (56.25%). Clinical presenting features of an obstructed valve (flash pulmonary oedema with or without clinically audible prosthetic valve clicks) were documented in the…

Subjects/Keywords: Prosthetic heart valves.; Communicable diseases.; Developing world.; Prosthetic dysfunction.; Reoperative valve surgery.; Heart patients.; Heart disease.

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Chih-Yuan, C. (2017). A 10-year institutional review of surgery for structural valve dysfunction in the developing world. (Thesis). University of KwaZulu-Natal. Retrieved from https://researchspace.ukzn.ac.za/handle/10413/18495

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Chih-Yuan, Chen. “A 10-year institutional review of surgery for structural valve dysfunction in the developing world.” 2017. Thesis, University of KwaZulu-Natal. Accessed April 11, 2021. https://researchspace.ukzn.ac.za/handle/10413/18495.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Chih-Yuan, Chen. “A 10-year institutional review of surgery for structural valve dysfunction in the developing world.” 2017. Web. 11 Apr 2021.

Vancouver:

Chih-Yuan C. A 10-year institutional review of surgery for structural valve dysfunction in the developing world. [Internet] [Thesis]. University of KwaZulu-Natal; 2017. [cited 2021 Apr 11]. Available from: https://researchspace.ukzn.ac.za/handle/10413/18495.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Chih-Yuan C. A 10-year institutional review of surgery for structural valve dysfunction in the developing world. [Thesis]. University of KwaZulu-Natal; 2017. Available from: https://researchspace.ukzn.ac.za/handle/10413/18495

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Missouri – Kansas City

20. Omer, Mohamed. Thirty-Day Readmissions after Early versus Delayed Discharge after Uncomplicated Transcatheter Aortic Valve Replacement: Insights from the Nationwide Readmissions Database.

Degree: 2019, University of Missouri – Kansas City

URL: http://hdl.handle.net/10355/69011

► Early discharge after transcatheter aortic valve replacement (TAVR) has generally shown to be safe; however, studies have been limited to single centers or trial populations,… (more)

▼ Early discharge after transcatheter aortic valve replacement (TAVR) has generally shown to be safe; however, studies have been limited to single centers or trial populations, making their generalizability unclear. This study sought to examine the rate of rehospitalization after early vs. late discharge following uncomplicated TAVR in an unselected population, to explore the variability in early discharge across sites, and to investigate factors associated with failure of early discharge. Using the National Readmission Databases (1/2014-9/2015), we compared 30-day readmission rates between early (<3 days) vs late (≥3 days) discharges after uncomplicated transfemoral TAVR (propensity matched cohort) using Kaplan-Meier methods. Additionally, we examined factors associated with failure of early discharge using logistic regression and testing for interactions of patient factors with discharge strategy. Among 4,955 hospitalizations for uncomplicated TAVR, 1857 (37%) were discharged early with substantial site-level variability (range 0-87%; median odds ratio 3.69). In the propensity matched cohort (n=3346), there were similar rates of 30-day readmission by discharge strategy (early vs. late: 10.3% vs. 10.6%; stratified log-rank p=0.555). There was a statistically significant interaction between discharge strategy and number of chronic conditions (p=0.007), where readmission rates were lower in patients discharged early versus late. In a matched cohort of real-world patients, early discharge after uncomplicated TAVR was not associated with a higher rate of 30-day rehospitalization, yet there was significant variability in early discharge across US hospitals. Furthermore, we were unable to identify any patients who appeared to benefit for longer inpatient monitoring. Novel strategies should be explored to safely increase the rate of early discharge after uncomplicated TAVR to improve patient outcomes. Advisors/Committee Members: Smolderen, Kim G. (advisor).

Subjects/Keywords: Heart valves – Surgery; Hospital utilization – Length of stay; Heart Valves – surgery; Length of Stay; Patient Discharge; Thesis – University of Missouri – Kansas City – Medicine

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Omer, M. (2019). Thirty-Day Readmissions after Early versus Delayed Discharge after Uncomplicated Transcatheter Aortic Valve Replacement: Insights from the Nationwide Readmissions Database. (Thesis). University of Missouri – Kansas City. Retrieved from http://hdl.handle.net/10355/69011

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Omer, Mohamed. “Thirty-Day Readmissions after Early versus Delayed Discharge after Uncomplicated Transcatheter Aortic Valve Replacement: Insights from the Nationwide Readmissions Database.” 2019. Thesis, University of Missouri – Kansas City. Accessed April 11, 2021. http://hdl.handle.net/10355/69011.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Omer, Mohamed. “Thirty-Day Readmissions after Early versus Delayed Discharge after Uncomplicated Transcatheter Aortic Valve Replacement: Insights from the Nationwide Readmissions Database.” 2019. Web. 11 Apr 2021.

Vancouver:

Omer M. Thirty-Day Readmissions after Early versus Delayed Discharge after Uncomplicated Transcatheter Aortic Valve Replacement: Insights from the Nationwide Readmissions Database. [Internet] [Thesis]. University of Missouri – Kansas City; 2019. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10355/69011.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Omer M. Thirty-Day Readmissions after Early versus Delayed Discharge after Uncomplicated Transcatheter Aortic Valve Replacement: Insights from the Nationwide Readmissions Database. [Thesis]. University of Missouri – Kansas City; 2019. Available from: http://hdl.handle.net/10355/69011

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Oklahoma State University

21. Ngwe, Ek Ching. Biocompatible Flow Chamber to Study the Hemodynamic Performance of Prosthetic Heart Valves.

Degree: Mechanical & Aerospace Engineering, 2010, Oklahoma State University

URL: http://hdl.handle.net/11244/10010

► Heart valve diseases claim more than 250,000 victims each year in the United States. One option to treat a diseased heart valve is to replace… (more)

▼ Heart valve diseases claim more than 250,000 victims each year in the United States. One option to treat a diseased heart valve is to replace it with a prosthetic heart valve. There are two main types of prosthetic heart valves, mechanical heart valves and bioprosthetic heart valves. The goal of this study was to build a biocompatible flow chamber (following the design of a left ventricular assist device) to study the hemodynamic performance of prosthetic heart valves. The flow chamber consists of two fluid chambers separated by a flexible latex diaphragm. One chamber is filled with water (water chamber) and connected to a Harvard reciprocating pump, which drives the diaphragm to move up and down and causes fluid in the other chamber (testing fluid chamber) to circulate through two heart valves. The biocompatibility of this flow chamber towards blood platelets and red blood cells were tested under static and dynamic conditions. For static testing, washed platelets were placed in the testing fluid chamber for up to 5 hours. Samples were taken out every hour and platelet surface P-selectin expression was measured using flow cytometry. To investigate the effect of the chamber on red blood cells, whole blood was placed in the test chamber for up to 6 hours. Hemolysis was measured every hour (at 540 nm). For dynamic testing, two St. Jude bileaflet mechanical heart valves were placed into the testing fluid chamber to control the flow direction. The flow rate of the system was fixed at 5 L/min with a stroke volume of 80mL and stroke rate of 72 min-1. The systolic /diastolic ratio was 0.375. Washed platelets were circulated in the chamber for 90 minutes and platelet surface P-selectin expression was examined every 15 minutes. For hemolysis measurement, whole blood was circulated through the two heart valves for 90 minutes and blood samples were taken every 15 minutes. The results demonstrated that the flow chamber did not induce hemolysis and platelet activation under static or dynamic conditions, with or without the St. Jude bileaflet mechanical heart valves. In parallel, a 3D computational fluid dynamics model was built to study the flow conditions in the flow chamber. The results indicated that the design of the flow chamber did not induce any turbulence in the testing fluid chamber (maximum Reynolds number was ~2100), which is desirable to study cellular functions. These results demonstrated the feasibility of using this flow chamber to study the hemodynamic performance of prosthetic heart valves. Advisors/Committee Members: Yin, Wei (advisor), Rubenstein, David A. (committee member), Delahoussaye, Ronald D. (committee member).

Subjects/Keywords: biocompatibility; flow chamber; hemodynamics of heart valves; prosthetic heart valves

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Ngwe, E. C. (2010). Biocompatible Flow Chamber to Study the Hemodynamic Performance of Prosthetic Heart Valves. (Thesis). Oklahoma State University. Retrieved from http://hdl.handle.net/11244/10010

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Ngwe, Ek Ching. “Biocompatible Flow Chamber to Study the Hemodynamic Performance of Prosthetic Heart Valves.” 2010. Thesis, Oklahoma State University. Accessed April 11, 2021. http://hdl.handle.net/11244/10010.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Ngwe, Ek Ching. “Biocompatible Flow Chamber to Study the Hemodynamic Performance of Prosthetic Heart Valves.” 2010. Web. 11 Apr 2021.

Vancouver:

Ngwe EC. Biocompatible Flow Chamber to Study the Hemodynamic Performance of Prosthetic Heart Valves. [Internet] [Thesis]. Oklahoma State University; 2010. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/11244/10010.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Ngwe EC. Biocompatible Flow Chamber to Study the Hemodynamic Performance of Prosthetic Heart Valves. [Thesis]. Oklahoma State University; 2010. Available from: http://hdl.handle.net/11244/10010

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

22. Moíse Dalva. Estudo do remodelamento ventricular e dos anéis valvares na cardiomiopatia dilatada: avaliação anátomo-histopatológica.

Degree: 2012, University of São Paulo

URL: http://www.teses.usp.br/teses/disponiveis/5/5156/tde-05042012-085911/

►

Introdução: A insuficiência cardíaca congestiva (ICC) ocasionada pela cardiomiopatia dilatada idiopática (CMDId) constitui-se em quadro causador de grande impacto na saúde pública, apresentando morbidade e… (more)

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Introdução: A insuficiência cardíaca congestiva (ICC) ocasionada pela cardiomiopatia dilatada idiopática (CMDId) constitui-se em quadro causador de grande impacto na saúde pública, apresentando morbidade e mortalidade significativas, porém muitos aspectos referentes à sua fisiopatologia ainda permanecem desconhecidos, de modo que trabalhos que estudem tais aspectos poderão contribuir para melhor entendimento desta entidade. Objetivos: Avaliar aspectos anatômicos e histológicos de corações com CMDId e compará-los a um grupo controle de corações normais, obtendo-se as medidas dos perímetros dos anéis atrioventriculares direito (AVD) e esquerdo (AVE) e dos ventrículos direito (VD) e esquerdo (VE) bem como a porcentagem por área de fibras colágenas e elásticas dos anéis atrioventriculares direito e esquerdo. Métodos: Foram analisados 13 corações de pacientes que faleceram vítimas de CMDId e 13 corações normais de pacientes que faleceram por causas não relacionadas à doenças cardiovasculares. Os corações foram fixados em formol, dissecados de forma a manter-se apenas os anéis atrioventriculares e a massa ventricular, com posterior laminação desta em segmentos transversais correspondentes a 20%, 50% e 80% da distância compreendida entre o sulco atrioventricular e o ápice ventricular esquerdo. Os cortes assim obtidos foram submetidos à digitalização fotográfica, que permitiu a aferição de ambos os perímetros ventriculares por meio de software específico, tornando possível a comparação de tais medidas entre os grupos e os segmentos. Os anéis atrioventriculares foram posteriormente dissecados, fotografados e medidos digitalmente para aferição das medidas perimetrais a direita e a esquerda, sendo posteriormente enviados ao laboratório de anatomia patológica, sendo realizadas colorações por meio de hematoxilinaeosina, picrossírius e resorcina fuccina oxidada, permitindo estudo das fibras colágenas e elásticas. Resultados: Com relação aos segmentos ventriculares, notou-se que no grupo CMDId ocorre dilatação nos segmentos apical, equatorial e basal, tanto a direita quanto a esquerda A medida do AVD foi maior no grupo CMDId , não havendo diferença estatisticamente significante com relação ao AVE entre os dois grupos. Com relação ao percentual por área de fibras colágenas, tanto o AVE quanto o AVD apresentaram percentagem de fibras menor no grupo CMDId em relação ao grupo normal. Com relação ao percentual por área de fibras elásticas, não houve diferença entre os grupos. Conclusões: Ocorre alteração da geometria ventricular com dilatação tanto a direita quanto a esquerda no grupo CMDId, porém com comportamento distinto entre o VE e o VD. O anel atrioventricular esquerdo não se dilata, ao contrário do direito, a despeito do fato de em ambos ocorrer diminuição da área total de colágeno, sugerindo que o mecanismo de dilatação possa apresentar particularidades oriundas de diferenças estruturais e pressóricas em ambos os ventrículos

Introduction: Congestive heart failure caused by idiopathic dilated cardiomyopathy causes…

Advisors/Committee Members: Fabio Biscegli Jatene, Richard Halti Cabral, Alexandre Ciappina Hueb, Luiz Augusto Ferreira Lisboa, Marco Antonio Volpe.

Subjects/Keywords: Cardiomiopatia dilatada/patologia; Coração/anatomia & histologia; Coração/patologia; Valva mitral/anatomia & histologia; Valva tricúspide/anatomia & histologia; Cardiomyopathy dilated; Heart anatomy; Heart pathology; Mitral valves anatomy; Tricuspid valves anatomy

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Dalva, M. (2012). Estudo do remodelamento ventricular e dos anéis valvares na cardiomiopatia dilatada: avaliação anátomo-histopatológica. (Doctoral Dissertation). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/5/5156/tde-05042012-085911/

Chicago Manual of Style (16^th Edition):

Dalva, Moíse. “Estudo do remodelamento ventricular e dos anéis valvares na cardiomiopatia dilatada: avaliação anátomo-histopatológica.” 2012. Doctoral Dissertation, University of São Paulo. Accessed April 11, 2021. http://www.teses.usp.br/teses/disponiveis/5/5156/tde-05042012-085911/.

MLA Handbook (7^th Edition):

Dalva, Moíse. “Estudo do remodelamento ventricular e dos anéis valvares na cardiomiopatia dilatada: avaliação anátomo-histopatológica.” 2012. Web. 11 Apr 2021.

Vancouver:

Dalva M. Estudo do remodelamento ventricular e dos anéis valvares na cardiomiopatia dilatada: avaliação anátomo-histopatológica. [Internet] [Doctoral dissertation]. University of São Paulo; 2012. [cited 2021 Apr 11]. Available from: http://www.teses.usp.br/teses/disponiveis/5/5156/tde-05042012-085911/.

Council of Science Editors:

Dalva M. Estudo do remodelamento ventricular e dos anéis valvares na cardiomiopatia dilatada: avaliação anátomo-histopatológica. [Doctoral Dissertation]. University of São Paulo; 2012. Available from: http://www.teses.usp.br/teses/disponiveis/5/5156/tde-05042012-085911/

University of California – Irvine

23. Zuke, Samuel David. Feasibility Studies on Using a Thermoplastic Polyurethane Scaffold for Hybrid Tissue-Engineered Heart Valves.

Degree: Biomedical Engineering, 2017, University of California – Irvine

URL: http://www.escholarship.org/uc/item/6kg0d00z

► ABSTRACT OF THE THESISFeasibility Studies on Using a Thermoplastic Polyurethane Scaffold for Hybrid Tissue-Engineered Heart ValvesBySamuel David ZukeMaster of Science in Biomedical EngineeringUniversity of California,… (more)

Subjects/Keywords: Biomedical engineering; Biomechanics; Cellular biology; Heart Valves; interstitial cells; Polymers; Polyurethane; scaffolds; Tissue-engineering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Zuke, S. D. (2017). Feasibility Studies on Using a Thermoplastic Polyurethane Scaffold for Hybrid Tissue-Engineered Heart Valves. (Thesis). University of California – Irvine. Retrieved from http://www.escholarship.org/uc/item/6kg0d00z

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Zuke, Samuel David. “Feasibility Studies on Using a Thermoplastic Polyurethane Scaffold for Hybrid Tissue-Engineered Heart Valves.” 2017. Thesis, University of California – Irvine. Accessed April 11, 2021. http://www.escholarship.org/uc/item/6kg0d00z.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Zuke, Samuel David. “Feasibility Studies on Using a Thermoplastic Polyurethane Scaffold for Hybrid Tissue-Engineered Heart Valves.” 2017. Web. 11 Apr 2021.

Vancouver:

Zuke SD. Feasibility Studies on Using a Thermoplastic Polyurethane Scaffold for Hybrid Tissue-Engineered Heart Valves. [Internet] [Thesis]. University of California – Irvine; 2017. [cited 2021 Apr 11]. Available from: http://www.escholarship.org/uc/item/6kg0d00z.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Zuke SD. Feasibility Studies on Using a Thermoplastic Polyurethane Scaffold for Hybrid Tissue-Engineered Heart Valves. [Thesis]. University of California – Irvine; 2017. Available from: http://www.escholarship.org/uc/item/6kg0d00z

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Florida International University

24. Salinas, Manuel. Heart Valve Tissue Engineering: A Study of Time Varying Effects and Sample Geometry.

Degree: MS, Biomedical Engineering, 2011, Florida International University

URL: https://digitalcommons.fiu.edu/etd/522 ; 10.25148/etd.FI11120806 ; FI11120806

► Mechanical conditioning has been shown to promote tissue formation in a wide variety of tissue engineering efforts. However the underlying mechanisms by which external… (more)

Subjects/Keywords: Tissue Engieering; heart valves; steady; pulsatile; computational fluid dynamics; quasi-static; stem cells

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Salinas, M. (2011). Heart Valve Tissue Engineering: A Study of Time Varying Effects and Sample Geometry. (Thesis). Florida International University. Retrieved from https://digitalcommons.fiu.edu/etd/522 ; 10.25148/etd.FI11120806 ; FI11120806

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Salinas, Manuel. “Heart Valve Tissue Engineering: A Study of Time Varying Effects and Sample Geometry.” 2011. Thesis, Florida International University. Accessed April 11, 2021. https://digitalcommons.fiu.edu/etd/522 ; 10.25148/etd.FI11120806 ; FI11120806.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Salinas, Manuel. “Heart Valve Tissue Engineering: A Study of Time Varying Effects and Sample Geometry.” 2011. Web. 11 Apr 2021.

Vancouver:

Salinas M. Heart Valve Tissue Engineering: A Study of Time Varying Effects and Sample Geometry. [Internet] [Thesis]. Florida International University; 2011. [cited 2021 Apr 11]. Available from: https://digitalcommons.fiu.edu/etd/522 ; 10.25148/etd.FI11120806 ; FI11120806.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Salinas M. Heart Valve Tissue Engineering: A Study of Time Varying Effects and Sample Geometry. [Thesis]. Florida International University; 2011. Available from: https://digitalcommons.fiu.edu/etd/522 ; 10.25148/etd.FI11120806 ; FI11120806

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Vanderbilt University

25. Sewell-Loftin, Mary Kathryn. Mechanoregulation of endocardial to mesenchymal transformation and subsequent remodeling during heart valve development.

Degree: PhD, Biomedical Engineering, 2014, Vanderbilt University

URL: http://hdl.handle.net/1803/10940

► Nearly 300,000 heart valve (HV) replacement surgeries are performed annually, including both pediatric patients with valvular defects and elderly patients suffering from degenerative or calcific… (more)

▼ Nearly 300,000 heart valve (HV) replacement surgeries are performed annually, including both pediatric patients with valvular defects and elderly patients suffering from degenerative or calcific valve diseases. Worldwide, the incidence of congenital heart defects is ~1% of live births, and 1 in 4 of these require valve replacement surgery. Currently, the clinical available prostheses are classified as mechanical or bioprosthetic and present significant disadvantages for both young and old patient populations. For mechanical valves, typically comprised of Teflon- or silicone-based polymers and metals, the risk of thrombosis formation requires patients to remain on anticoagulant therapy. Bioprosthetic valves of either bovine or porcine origin introduce increased risk of calcific lesion formation after implantation. All prostheses have life spans of 10-20 years, which can necessitate multiple reoperations in the pediatric patient population who will also require larger HV replacements as they grow. The next generation of HV prosthetics needs to be viable, capable of actively responding to a patient’s needs to grow and remodel. To accomplish this, tissue engineered HVs (TEHVs) are moving towards natural polymer based scaffolds with cell-directive cues. However, to better develop these systems we will need to elucidate important biomechanical properties of HVs. By enhancing our understanding of mechanical factors essential in the formation and development of native HV leaflets, we can design improved viable TEHV scaffolds. The overall goal of this research is to elucidate the interactions between biomechanics and valvular cell processes crucial in HV leaflet development and remodeling. We are also interested in refining an in vitro model for epithelial to mesenchymal transformation (EMT), a critical initial step in the formation of HVs, that allows for interrogation of relevant biomechanical factors. We believe these studies provide novel insight into the relationship between mechanoregulation of EMT and HV tissue biomechanics. Advisors/Committee Members: Joey V. Barnett (committee member), Christopher B. Brown (committee member), Craig L. Duvall (committee member), Hak-Joon Sung (committee member), W. David Merryman (Committee Chair).

Subjects/Keywords: hyodrgels; hyaluronic acid; atomic force microscopy; heart valves; biomechanics; epithelial to mesenchymal transformation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Sewell-Loftin, M. K. (2014). Mechanoregulation of endocardial to mesenchymal transformation and subsequent remodeling during heart valve development. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/10940

Chicago Manual of Style (16^th Edition):

Sewell-Loftin, Mary Kathryn. “Mechanoregulation of endocardial to mesenchymal transformation and subsequent remodeling during heart valve development.” 2014. Doctoral Dissertation, Vanderbilt University. Accessed April 11, 2021. http://hdl.handle.net/1803/10940.

MLA Handbook (7^th Edition):

Sewell-Loftin, Mary Kathryn. “Mechanoregulation of endocardial to mesenchymal transformation and subsequent remodeling during heart valve development.” 2014. Web. 11 Apr 2021.

Vancouver:

Sewell-Loftin MK. Mechanoregulation of endocardial to mesenchymal transformation and subsequent remodeling during heart valve development. [Internet] [Doctoral dissertation]. Vanderbilt University; 2014. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/1803/10940.

Council of Science Editors:

Sewell-Loftin MK. Mechanoregulation of endocardial to mesenchymal transformation and subsequent remodeling during heart valve development. [Doctoral Dissertation]. Vanderbilt University; 2014. Available from: http://hdl.handle.net/1803/10940

Florida International University

26. Gallocher, Siobhain Lynn. Durability Assessment of Polymer Trileaflet Heart Valves.

Degree: Biomedical Engineering, 2007, Florida International University

URL: https://digitalcommons.fiu.edu/etd/54 ; 10.25148/etd.FI08081519 ; FI08081519

► The durability of a polymer trileaflet valve is dependent on leaflet stress concentrations, so valve designs that reduce stress can, hypothetically, increase durability. Design… (more)

▼ The durability of a polymer trileaflet valve is dependent on leaflet stress concentrations, so valve designs that reduce stress can, hypothetically, increase durability. Design aspects that are believed to contribute to reduced leaflet stress include stent flexibility, parabolic coaptation curvature, and leaflet anisotropy. With this in mind, the purpose of this investigation was to elucidate what specific combinations of these parameters promote optimal acute and long-term valve function. A combination of four stent designs, seven leaflet reinforcement materials, and three coaptation geometries were evaluated through a combination of experimentation and modeling. Static tensile and Poisson’s ratio tests and dynamic tensile fatigue testing were used to evaluate the individual leaflet components; and hydrodynamic testing and accelerated valve fatigue was used to assess complete valve prototypes. The two most successful designs included a 0.40 mm thick knit-reinforced valve with a fatigue life of 10.35 years, and a 0.20 mm thick knit-reinforced valve with a 28.9 mmHg decrease in pressure drop over the former. A finite element model was incorporated to verify the impact of the above-mentioned parameters on leaflet stress concentrations. Leaflet anisotropy had a large impact on stress concentrations, and matching the circumferential modulus to that of the natural valve showed the greatest benefit. Varying the radial modulus had minimal impact. Varying coaptation geometry had no impact, but stent flexibility did have a marked effect on the stress at the top of the commissure, where a completely rigid stent resulted in a higher peak stress than a flexible stent (E = 385 MPa). In conclusion, stent flexibility and leaflet anisotropy do effect stress concentrations in the SIBS trileaflet valve, but coaptation geometry does not. Regions of high stress concentrations were linked to failure locations in vitro, so a fatigue prediction model was developed from the S/N curves generated during dynamic tensile testing of the 0.20 mm knit-reinforced leaflets. Failure was predicted at approximately 400 million cycles (10 years) at the top of the commissure. In vitro fatigue of this valve showed failure initiation after approximately 167 million cycles (4.18 years), but it was related to a design defect that is subsequently being changed. Advisors/Committee Members: Richard T. Schoephoerster.

Subjects/Keywords: FEM; fatigue; heart valves; hydrodynamic testing

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APA (6^th Edition):

Gallocher, S. L. (2007). Durability Assessment of Polymer Trileaflet Heart Valves. (Thesis). Florida International University. Retrieved from https://digitalcommons.fiu.edu/etd/54 ; 10.25148/etd.FI08081519 ; FI08081519

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Gallocher, Siobhain Lynn. “Durability Assessment of Polymer Trileaflet Heart Valves.” 2007. Thesis, Florida International University. Accessed April 11, 2021. https://digitalcommons.fiu.edu/etd/54 ; 10.25148/etd.FI08081519 ; FI08081519.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Gallocher, Siobhain Lynn. “Durability Assessment of Polymer Trileaflet Heart Valves.” 2007. Web. 11 Apr 2021.

Vancouver:

Gallocher SL. Durability Assessment of Polymer Trileaflet Heart Valves. [Internet] [Thesis]. Florida International University; 2007. [cited 2021 Apr 11]. Available from: https://digitalcommons.fiu.edu/etd/54 ; 10.25148/etd.FI08081519 ; FI08081519.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Gallocher SL. Durability Assessment of Polymer Trileaflet Heart Valves. [Thesis]. Florida International University; 2007. Available from: https://digitalcommons.fiu.edu/etd/54 ; 10.25148/etd.FI08081519 ; FI08081519

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Gothenburg / Göteborgs Universitet

27. Barone, Angela. Studies on glycosphingolipids in regenerative medicine.

Degree: 2014, University of Gothenburg / Göteborgs Universitet

URL: http://hdl.handle.net/2077/35450

► Regenerative medicine, including stem cell based therapies and xenotransplantation, is a new and developing field that aims to restore normal function in end stage cell/organ… (more)

▼ Regenerative medicine, including stem cell based therapies and xenotransplantation, is a new and developing field that aims to restore normal function in end stage cell/organ failure. However, in therapeutic settings involving transfer of cells with a different genetic background, these cells will expose the recipient to non-self cell surface antigenic determinants that may evoke an immune response and subsequent graft damage. Thus, the cell surface antigen expression of cells aimed for transplantation has to be defined. The first part of this study deals with glycosphingolipids of human embryonic stem cells (hESC). The glycosphingolipids were isolated from a relatively high number of cells (1x109 cells/cell line) allowing separation of the glycosphingolipids into total non-acid and acid fractions, that could be further separated into sub-fractions. These fractions were structurally characterized by mass spectrometry, proton NMR spectroscopy and binding studies with carbohydrate binding ligands. This allowed identification of several glycosphingolipids not previously described in hESC. In the non-acid glycosphingolipid fractions several novel blood group H, Lex and Ley compounds based on neolacto core chains were characterized, in addition to the already identified lacto- and globo-series glycosphingolipids. The acidic glycosphingolipid fractions contained several novel hESC acid glycosphingolipids, like the gangliosides sialyl-lactotetraosylceramide and sialyl-globotetraosylceramide, and the sulfated glycosphingolipids sulfatide, sulf-lactosylceramide and sulf-globopentaosylceramide. The cellular and subcellular distribution of sialyl-lactotetraosylceramide and sulfated glycosphingolipids in hESC and in human induced pluripotent stem cells (hiPSC) was explored by flow cytometry, immunohistochemistry and electron microscopy. A high cell surface expression of sialyl-lactotetra on hESC and hiPSC was demonstrated, whereas the sulfated glycosphingolipids were restricted to intracellular compartments. During differentiation of hiPSC into hepatocyte-like cells a rapid down-regulation of the sialyl-lactotetra epitope was found. Taken together these data demonstrate that the sialyl-lactotetra carbohydrate sequence is a novel marker for undifferentiated human pluripotent stem cells. Diseased human heart valves are substituted with either mechanical valves or biological heart valves (BHV) produced from porcine and bovine valves or pericardial tissues. The BHV function deteriorates with time partly due to an immunological process. The second part of the study aimed at defining carbohydrate antigens of porcine heart valves with a potential of being immune targets for this process. Here, a number of acidic glycosphingolipids (sulfatide and the gangliosides GM3, GM2, GM1, fucosyl-GM1, GD3 and GD1a) and non-acid glycosphingolipids (globotetraosylceramide, H type 2 pentaosylceramide, fucosyl-gangliotetraosylceramide and Galα3neolacto-tetraosylceramide) were characterized. Interestingly, no gangliosides with the non-Gal…

Subjects/Keywords: Glycosphingolipids; human embryonic stem cells; Cell surface markers; porcine heart valves; xenotransplantation; regenerative medicinr

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Barone, A. (2014). Studies on glycosphingolipids in regenerative medicine. (Thesis). University of Gothenburg / Göteborgs Universitet. Retrieved from http://hdl.handle.net/2077/35450

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Barone, Angela. “Studies on glycosphingolipids in regenerative medicine.” 2014. Thesis, University of Gothenburg / Göteborgs Universitet. Accessed April 11, 2021. http://hdl.handle.net/2077/35450.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Barone, Angela. “Studies on glycosphingolipids in regenerative medicine.” 2014. Web. 11 Apr 2021.

Vancouver:

Barone A. Studies on glycosphingolipids in regenerative medicine. [Internet] [Thesis]. University of Gothenburg / Göteborgs Universitet; 2014. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/2077/35450.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Barone A. Studies on glycosphingolipids in regenerative medicine. [Thesis]. University of Gothenburg / Göteborgs Universitet; 2014. Available from: http://hdl.handle.net/2077/35450

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Iowa

28. Pena Silva, Ricardo Alfonso. Cardiovascular oxidative stress: recent findings on ACE2 And MAO.

Degree: PhD, Pharmacology, 2012, University of Iowa

URL: https://ir.uiowa.edu/etd/3366

► Oxidative stress is associated with development and progression of cardiovascular disease. Angiotensin II produces oxidative stress and endothelial dysfunction, and its actions may be… (more)

▼ Oxidative stress is associated with development and progression of cardiovascular disease. Angiotensin II produces oxidative stress and endothelial dysfunction, and its actions may be attenuated by the activity of angiotensin converting enzyme type 2 (ACE2) which converts angiotensin II to the vasoprotective peptide angiotensin (1-7). Similarly, increased oxidative stress is associated with aortic valve stenosis in humans and mice. In my thesis studies, I explore mechanisms of modulation and generation of oxidative stress in cerebral arteries and heart valves. First, I tested the hypothesis that ACE2 deficiency increases oxidative stress and vasomotor dysfunction in cerebral arteries, and examined the role of ACE2 in vascular aging. Vasomotor function was assessed in the basilar artery ex vivo of adult and old ACE2 deficient (ACE2-/y) and wild type (WT or ACE2+/y) mice. ACE2 was present, but at relatively low levels in cerebral arteries. Systolic blood pressure was similar in adult and old ACE2-/y and ACE2+/y mice. Maximal dilatation to acetylcholine was impaired in the basilar artery from adult ACE2-/y mice compared to adult ACE2+/y. In old mice, maximal vasodilatation to acetylcholine was impaired in ACE2+/y mice and severely impaired in ACE2-/y mice. The antioxidant tempol improved responses to acetylcholine in adult and old ACE2-/y and ACE2+/y mice. Nitrotyrosine staining in the basilar artery was increased in adult ACE2-/y mice and in old ACE2-/y and ACE2+/y mice relative to adult ACE2+/y, which indicates that oxidative stress was higher in cerebral arteries from ACE2 deficient mice and old mice. Expression of NADPH oxidase subunits Nox2 and p47phox, and of pro-inflammatory molecules Rcan1 and TNF alpha; was increased in cerebral arteries from old ACE2-/y and ACE2+/y mice. Additionally, I tested the hypothesis that serotonin induces oxidative stress in human heart valves, and examined mechanisms by which serotonin may increase reactive oxygen species (ROS). Superoxide (O2.-) was measured in heart valves from explanted human hearts that were not used for transplantation. Superoxide levels (lucigenin-enhanced chemiluminescence) were increased in homogenates of cardiac valves and pulmonary artery after incubation with serotonin. A non-specific inhibitor of flavin-oxidases (DPI), or inhibitors of monoamine oxidase-MAO (tranylcypromine and clorgyline), prevented serotonin-induced increase in O2.-. Dopamine, another MAO substrate which is increased in patients with carcinoid syndrome, also increased superoxide levels in heart valves, and this effect was attenuated by clorgyline. Apocynin did not prevent increases in O2.- during serotonin treatment. Addition of serotonin to recombinant human MAO-A generated superoxide, and this effect was prevented by an MAO inhibitor. In conclusion, I have demonstrated that ACE2 deficiency impairs vasomotor function in cerebral arteries from adult mice and augments endothelial dysfunction during aging. Oxidative stress plays a critical role in… Advisors/Committee Members: Heistad, Donald D. (supervisor).

Subjects/Keywords: Angiotensin Converting Enzyme Type 2; Angiotensin II; Cerebral Circulation; Heart Valves; Oxidative Stress; Pharmacology

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Pena Silva, R. A. (2012). Cardiovascular oxidative stress: recent findings on ACE2 And MAO. (Doctoral Dissertation). University of Iowa. Retrieved from https://ir.uiowa.edu/etd/3366

Chicago Manual of Style (16^th Edition):

Pena Silva, Ricardo Alfonso. “Cardiovascular oxidative stress: recent findings on ACE2 And MAO.” 2012. Doctoral Dissertation, University of Iowa. Accessed April 11, 2021. https://ir.uiowa.edu/etd/3366.

MLA Handbook (7^th Edition):

Pena Silva, Ricardo Alfonso. “Cardiovascular oxidative stress: recent findings on ACE2 And MAO.” 2012. Web. 11 Apr 2021.

Vancouver:

Pena Silva RA. Cardiovascular oxidative stress: recent findings on ACE2 And MAO. [Internet] [Doctoral dissertation]. University of Iowa; 2012. [cited 2021 Apr 11]. Available from: https://ir.uiowa.edu/etd/3366.

Council of Science Editors:

Pena Silva RA. Cardiovascular oxidative stress: recent findings on ACE2 And MAO. [Doctoral Dissertation]. University of Iowa; 2012. Available from: https://ir.uiowa.edu/etd/3366

University of Arkansas

29. Lam, Ngoc Thien. Multiscale investigation of the behavior of heart valve interstitial cells in response to pathological shape and mechanical stimulation.

Degree: PhD, 2018, University of Arkansas

URL: https://scholarworks.uark.edu/etd/2770

► Our works aim to provide an insight into how aortic valve interstitial cells (VICs) respond to pathological shape and mechanical stimulation as well as… (more)

▼ Our works aim to provide an insight into how aortic valve interstitial cells (VICs) respond to pathological shape and mechanical stimulation as well as the potential signaling pathway that mediates these responses, using a multiscale approach. A single cell model was developed to investigate the effect of altered shape on valve cell function as valve cells were reported to significantly deform during the cardiac cycle. Single VICs were controlled to take on features with different width-to-length aspect ratios that corresponded to the steady-state shapes adopted by VICs when stretched to 0%, 10% and 20%, respectively. It appeared that single VIC reorganized their cytoskeleton and increased cellular activities, including contractility, metabolism, proliferation and pathological activation, in response to shape alterations. This study provided a fundamental understanding of VIC behavior at single cell level. In order to further examine valve cell pathophysiology, a more physiologically-relevant 3-dimensional (3D) stretchable model was developed to better simulate natural heart valve environment. We developed and characterized a collagen-based scaffold for dynamic culture of heart VICs. This 3D scaffold was porous, biocompatible and mechanically robust. For this reason, it was utilized as a culture model for the subsequent cell signaling study where the role of fibroblast growth factor on valve cell biology was examined in the presence of mechanical stretching stimulation. Stretch magnitudes of 10% and 20% were used to mimic healthy and pathological conditions, respectively. We reported that the Akt/mTOR pathway was up-regulated at elevated 20% stretch which was associated with increased cell proliferation/metabolism. Treatment with fibroblast growth factor 1/ fibroblast growth factor 2 (FGF1/FGF2) significantly altered cellular responses such that they aided in cell proliferation at 10% stretch while reduced cell proliferation at 20% stretch. FGF1/FGF2 treatment was also able to reduce expression of activated markers in pathologically stretched cells, suggesting that FGF1/FGF2 signaling might be a potential target for drug therapies for heart valve treatment. Overall, this project provided a specific picture of how heart valve cells responded to pathological stimulations at multiscale levels and the involvement of FGF-receptor signaling. It is hoped that the knowledge gained from these studies could help to identify therapeutic targets for valvular disease treatment. Advisors/Committee Members: Kartik Balachandran, Jeffrey Wolchok, Gisela Erf.

Subjects/Keywords: Aortic Valve Disease; Biomechanics; Cell Behavior; Heart Valves; Mechanism; Valve Interstitial Cells; Cell Biology

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Lam, N. T. (2018). Multiscale investigation of the behavior of heart valve interstitial cells in response to pathological shape and mechanical stimulation. (Doctoral Dissertation). University of Arkansas. Retrieved from https://scholarworks.uark.edu/etd/2770

Chicago Manual of Style (16^th Edition):

Lam, Ngoc Thien. “Multiscale investigation of the behavior of heart valve interstitial cells in response to pathological shape and mechanical stimulation.” 2018. Doctoral Dissertation, University of Arkansas. Accessed April 11, 2021. https://scholarworks.uark.edu/etd/2770.

MLA Handbook (7^th Edition):

Lam, Ngoc Thien. “Multiscale investigation of the behavior of heart valve interstitial cells in response to pathological shape and mechanical stimulation.” 2018. Web. 11 Apr 2021.

Vancouver:

Lam NT. Multiscale investigation of the behavior of heart valve interstitial cells in response to pathological shape and mechanical stimulation. [Internet] [Doctoral dissertation]. University of Arkansas; 2018. [cited 2021 Apr 11]. Available from: https://scholarworks.uark.edu/etd/2770.

Council of Science Editors:

Lam NT. Multiscale investigation of the behavior of heart valve interstitial cells in response to pathological shape and mechanical stimulation. [Doctoral Dissertation]. University of Arkansas; 2018. Available from: https://scholarworks.uark.edu/etd/2770

University of Texas – Austin

30. Ayoub, Salma. The effect of mechanical stimuli on the mitral valve interstitial cell : implications for heart valve disease and surgical repair.

Degree: PhD, Biomedical Engineering, 2018, University of Texas – Austin

URL: http://hdl.handle.net/2152/65693

► In the diseases of the mitral valve (MV), such as mitral regurgitation (MR) and degenerative myxomatous MV disease (MMVD), several pathological factors have been shown… (more)

▼ In the diseases of the mitral valve (MV), such as mitral regurgitation (MR) and degenerative myxomatous MV disease (MMVD), several pathological factors have been shown to affect tissue structure and composition that ultimately lead to valve failure. Current clinical treatments for both functional and degenerative MR include repair by ring annuloplasty (AP). Though beneficial in the short-term, AP has been shown to be less promising long term with repair failure as high as 60%. Mechanical stress is a strong etiological factor: alterations in mechanical loading caused by surgical repair lead to stress-induced changes in mitral valve interstitial cell (MVIC) function that affect both tissue structure and composition, ultimately leading to repair failure. A common thread needed to address these issues is the link between tissue-level stresses and cellular homeostatic responses. MVIC deformation is a major driver for cellular mechanoregulation. As such, a quantitative understanding of MVIC responses to mechanical stimulation in vivo is necessary. We thus hypothesize that abnormal mechanical stimuli lead to non-physiological MVIC deformations that result in phenotypic activation and altered biosynthetic activity. Exploiting this knowledge can lead to improved surgical repair techniques for both functional and degenerative MR. We address our hypothesis in four parts. First, we evaluate the remodeling of the MV anterior leaflet after ischemic MR using an in vivo ovine model, laying out an essential prerequisite for the rest of the dissertation. Second, we characterize the three-dimensional microenvironment of the MVIC under physiological loading, allowing us to develop more structurally accurate computational models that incorporate the heterogeneities of the cellular microenvironment. Third, we use an integrated experimental-computational approach to elucidate the link between MVIC deformation and biosynthetic response in an intact tissue system under simplified deformations. And finally, we design and develop a more physiologically-relevant bioreactor and use it investigate the response of MVICs to a range of simulated physiological and non-physiological loading conditions. Our integrated approaches allowed us to identify MVIC deformation as a key player in leaflet tissue homeostatic regulation and use it as a metric that makes the critical link between in vitro responses to equivalent in vivo behavior. Advisors/Committee Members: Sacks, Michael S. (advisor), Ferrari, Giovanni (committee member), Baker, Aaron B. (committee member), Zoldan, Janet (committee member).

Subjects/Keywords: Heart valves; Mechanobiology; Collagen; Mitral valve; Mitral regurgitation; Ischemic mitral regurgitation; Mitral valve repair

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Ayoub, S. (2018). The effect of mechanical stimuli on the mitral valve interstitial cell : implications for heart valve disease and surgical repair. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/65693

Chicago Manual of Style (16^th Edition):

Ayoub, Salma. “The effect of mechanical stimuli on the mitral valve interstitial cell : implications for heart valve disease and surgical repair.” 2018. Doctoral Dissertation, University of Texas – Austin. Accessed April 11, 2021. http://hdl.handle.net/2152/65693.

MLA Handbook (7^th Edition):

Ayoub, Salma. “The effect of mechanical stimuli on the mitral valve interstitial cell : implications for heart valve disease and surgical repair.” 2018. Web. 11 Apr 2021.

Vancouver:

Ayoub S. The effect of mechanical stimuli on the mitral valve interstitial cell : implications for heart valve disease and surgical repair. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2018. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/2152/65693.

Council of Science Editors:

Ayoub S. The effect of mechanical stimuli on the mitral valve interstitial cell : implications for heart valve disease and surgical repair. [Doctoral Dissertation]. University of Texas – Austin; 2018. Available from: http://hdl.handle.net/2152/65693

Open Access Theses and Dissertations