Stress and Strain Analyses of Blood Vessels in Physiological and Pathological Conditions

2000 ◽  
pp. 29-38
Author(s):  
Hiroshi Yamada
Keyword(s):  
Blood Vessels ◽  
Stress And Strain ◽  
Pathological Conditions

scholarly journals An in vivo model allowing continuous observation of human vascular formation in the same animal over time

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yohei Tsukada ◽  
Fumitaka Muramatsu ◽  
Yumiko Hayashi ◽  
Chiaki Inagaki ◽  
Hang Su ◽  
...  
Keyword(s):  
Blood Vessel ◽  
Blood Vessels ◽  
Human Blood ◽  
Molecular Mechanisms ◽  
Human Tumor ◽  
Continuous Observation ◽  
In Vivo Models ◽  
Cranial Window ◽  
Pathological Conditions

AbstractAngiogenesis contributes to numerous pathological conditions. Understanding the molecular mechanisms of angiogenesis will offer new therapeutic opportunities. Several experimental in vivo models that better represent the pathological conditions have been generated for this purpose in mice, but it is difficult to translate results from mouse to human blood vessels. To understand human vascular biology and translate findings into human research, we need human blood vessel models to replicate human vascular physiology. Here, we show that human tumor tissue transplantation into a cranial window enables engraftment of human blood vessels in mice. An in vivo imaging technique using two-photon microscopy allows continuous observation of human blood vessels until at least 49 days after tumor transplantation. These human blood vessels make connections with mouse blood vessels as shown by the finding that lectin injected into the mouse tail vein reaches the human blood vessels. Finally, this model revealed that formation and/or maintenance of human blood vessels depends on VEGFR2 signaling. This approach represents a useful tool to study molecular mechanisms of human blood vessel formation and to test effects of drugs that target human blood vessels in vivo to show proof of concept in a preclinical model.

scholarly journals Quantitative Assessment of 3D Printed Blood Vessels Produced with J750™ Digital Anatomy™ for Suture Simulation

2022 ◽  
Author(s):  
Stefania Marconi ◽  
Valeria Mauri ◽  
Erika Negrello ◽  
Luigi Pugliese ◽  
Andrea Pietrabissa ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Soft Tissues ◽  
Surgical Simulation ◽  
Patient Specific ◽  
Morphological Aspects ◽  
Pathological Conditions ◽  
Surgical Simulations ◽  
Training Of Surgeons ◽  
3D Printed ◽  
Digital Anatomy

Blood vessels anastomosis is one of the most challenging and delicate tasks to learn in many surgical specialties, especially for vascular and abdominal surgeons. Such a critical skill implies a learning curve that goes beyond technical execution. The surgeon needs to gain proficiency in adapting gestures and the amount of force expressed according to the type of tissue he/she is dealing with. In this context, surgical simulation is gaining a pivotal role in the training of surgeons, but currently available simulators can provide only standard or simplified anatomies, without the chance of presenting specific pathological conditions and rare cases. 3D printing technology, allowing the manufacturing of extremely complex geometries, find a perfect application in the production of realistic replica of patient-specific anatomies. According to available technologies and materials, morphological aspects can be easily handled, while the reproduction of tissues mechanical properties still poses major problems, especially when dealing with soft tissues. The present work focuses on blood vessels, with the aim of identifying – by means of both qualitative and quantitative tests – materials combinations able to best mimic the behavior of the biological tissue during anastomoses, by means of J750™ Digital Anatomy™ technology and commercial photopolymers from Stratasys. Puncture tests and stitch traction tests are used to quantify the performance of the various formulations. Surgical simulations involving anastomoses are performed on selected clinical cases by surgeons to validate the results. A total of 37 experimental materials were tested and 2 formulations were identified as the most promising solutions to be used for anastomoses simulation. Clinical applicative tests, specifically selected to challenge the new materials, raised additional issues on the performance of the materials to be considered for future developments.

Strain distribution in small blood vessels with zero-stress state taken into consideration

1992 ◽  
Vol 262 (2) ◽  
pp. H544-H552 ◽  
Author(s):  
Y. C. Fung ◽  
S. Q. Liu
Keyword(s):  
Stress State ◽  
Blood Vessels ◽  
Pulmonary Arteries ◽  
Vena Cava ◽  
Large Error ◽  
Opening Angle ◽  
Stress And Strain ◽  
Passive Deformation ◽  
Angle Alpha ◽  
Residual Strains

The active and passive deformation of a blood vessel is related to the stress in it. Any analysis of stress and strain must begin with the zero-stress state. Recent reports on large blood vessels such as the aorta, pulmonary arteries, and vena cava have shown that, at zero-stress state, blood vessels are not tubes, but opens sectors. This report presents data on the zero-stress state of small blood vessels with lumen diameters down to approximately 50 microns. Zero-stress state of a vessel was obtained by cutting the vessel into rings and then the rings into sectors; each sector is characterized by an opening angle, alpha. In rat ileal and plantar arterioles, the opening angles are in the order of 100-250 degrees; those in the venules are in the order of 50-100 degrees. The effect of norepinephrine on the opening angle alpha is minor; it decreases alpha of the superior mesenteric artery, and increases alpha of the ileocecocolic and ileal arteries. EDTA has little effect on alpha of arteries greater than 100 microns in diameter, but decreases alpha of arteries less than 100 microns. The physiological meaning of the opening angle is demonstrated in terms of the residual strains in a vessel at the no-load state and homeostatic strains at normal blood pressure. The strains in real vessels are compared with those in hypothetical vessels having an opening angle of zero. It is shown that ignoring the opening angle will cause a large error in strain evaluation.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural 3-D Constitutive Model for the Passive Arterial Media and Its Experimental Validation

2010 ◽  
Author(s):  
Yaniv Hollander ◽  
David Durban ◽  
Xiao Lu ◽  
Ghassan S. Kassab ◽  
Yoram Lanir
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Experimental Validation ◽  
Stress And Strain ◽  
Arterial Tree ◽  
Pathological Conditions ◽  
Unloaded State ◽  
Reliable Model ◽  
Biological Reaction ◽  
Shed Light

The mechanical properties of arteries are of essential importance in hemodynamics and blood wave propagation along the arterial tree. They play a pivotal role in determining the local state of micro-stress imposed on the vessel cells and the cells’ consequent biological reaction. The wall is mechanically nonlinear, anisotropic and heterogeneous, and subjected in the unloaded state to residual stress and strain. Reliable model prediction of arterial response under physiological loads and pathological conditions could help clarify their function, and shed light on the processes leading to initiation and progression of diseases and their clinical treatment.

scholarly journals Biomechanical Properties of Bone and Mucosa for Design and Application of Dental Implants

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2845
Author(s):  
Michael Gasik ◽  
France Lambert ◽  
Miljana Bacevic
Keyword(s):  
Mechanical Properties ◽  
Dental Implants ◽  
Soft Tissues ◽  
Biomechanical Properties ◽  
Stress And Strain ◽  
Pathological Conditions ◽  
Strain Components ◽  
Mechanical Factors ◽  
Movement And Deformation ◽  
Mechanical Movement

Dental implants’ success comprises their proper stability and adherence to different oral tissues (integration). The implant is exposed to different mechanical stresses from swallowing, mastication and parafunctions for a normal tooth, leading to the simultaneous mechanical movement and deformation of the whole structure. The knowledge of the mechanical properties of the bone and gingival tissues in normal and pathological conditions is very important for the successful conception of dental implants and for clinical practice to access and prevent potential failures and complications originating from incorrect mechanical factors’ combinations. The challenge is that many reported biomechanical properties of these tissues are substantially scattered. This study carries out a critical analysis of known data on mechanical properties of bone and oral soft tissues, suggests more convenient computation methods incorporating invariant parameters and non-linearity with tissues anisotropy, and applies a consistent use of these properties for in silico design and the application of dental implants. Results show the advantages of this approach in analysis and visualization of stress and strain components with potential translation to dental implantology.

scholarly journals Effect of ginger extract on angiogenesis using CAM assay

2017 ◽  
Vol 12 (3) ◽  
pp. 348 ◽  
Author(s):  
Muhammad Farhan Bashir ◽  
Muhammad Imran Qadir
Keyword(s):  
Blood Vessels ◽  
Critical Role ◽  
Video Clip ◽  
Cam Assay ◽  
Ginger Extract ◽  
Angiogenic Activity ◽  
Blood Vessel Formation ◽  
Pathological Conditions ◽  
Full Screen ◽  
Different Doses

<p>Angiogenesis performs a critical role in the embryonic growth and several pathological conditions in cancer. This study evaluated the anti-angiogenic properties of the ginger extract using CAM assay. Ginger extract was prepared by methanol. Window was made after 5 days of incubation of eggs and the ginger extract was applied on day 6 at different doses (20, 50, 75 and 150 µL). SPIP software was utilized to investigate the CAM region and diameter of blood vessels. Ginger extract proved anti-angiogenic cones-quence by decreasing the diameter of CAM of blood vessels. Comparable results were attained at dilution of 150 µL. The anti-angiogenic activity of ginger extract implicates its possible application for diseases where inhibition of blood vessel formation is desired.</p><p><strong>Video Clip of Methodology</strong>:</p><p>7 min 32 sec:   <a href="https://www.youtube.com/v/ZUY2cY09Otg">Full screen</a>   <a href="https://www.youtube.com/watch?v=ZUY2cY09Otg">Alternate</a> </p>

An Anti-VEGF Antibody, in Combination with Bortezomib, Markedly Inhibits Tumor Growth in SCID-hu Models of Human Multiple Myeloma.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4802-4802 ◽  
Author(s):  
Richard A. Campbell ◽  
Eric Sanchez ◽  
Jeffrey Steinberg ◽  
Michael Share ◽  
Joseph Wang ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Tumor Growth ◽  
Blood Vessels ◽  
Critical Role ◽  
Single Agent ◽  
Mouse Serum ◽  
Treatment Groups ◽  
Pathological Conditions ◽  
Anti Vegf ◽  
Agent Treatment

Abstract Vascular endothelial growth factor (VEGF) is an important signaling protein that plays a critical role in vasculogenesis and angiogenesis, and serves as one of the contributors to physiological or pathological conditions that can stimulate the formation of new blood vessels. The uncontrolled growth of new blood vessels is an important contributor to a number of pathological conditions, including multiple myeloma (MM). In support of this, bone marrow angiogenesis has been shown to correlate with disease status and poor prognosis in MM. VEGF also directly induces myeloma cell proliferation. We previously evaluated the effects of single agent mouse/human anti-VEGF antibody G6.31 (Campbell et al, Blood (ASH Annual Meeting Abstracts), Nov 2006) in several of our mouse models of human MM. In this study, we evaluated the effects of the same anti-VEGF antibody in combination with bortezomib or lenalidomide. Severe combined immunodeficient (SCID) mice were implanted into the left superficial gluteal muscle with either a 2.0 – 4.0 mm3 fragment from a patient when she was bortezomib-sensitive, LAGκ-1A, or resistant, LAGκ-1B. The tumors were allowed to grow for 21 days at which time human IgG levels were detectable in the mouse serum, and mice were blindly assigned into treatment groups (n=10 mice/group). Treatment groups consisted of a control IgG antibody or anti-VEGF antibody administered via i.p. injection twice weekly at a dose of 2 mg/kg, bortezomib administered via intravenous injection at a dose of 0.25 or 0.5 mg/kg twice weekly, lenalidomide administered via i.p. injection at a dose of 50 mg/kg daily × 5 per week, anti-VEGF antibody (2 mg/kg) + bortezomib (0.25 or 0.5 mg/kg), and anti-VEGF (2 mg/kg) + lenalidomide (50 mg/kg). Mice receiving the combination therapy of anti-VEGF + bortezomib (0.5 mg//kg) antibody showed marked inhibition of tumor growth and reduction of paraprotein levels compared to mice receiving control antibody. Notably, this combination also produced much more marked anti-MM effects compared to bortezomib treatment alone, anti-VEGF antibody alone, or vehicle alone. This combination was well tolerated. In contrast, mice receiving the combination of anti-VEGF antibody + lenalidomide showed no significant differences in tumor volume or hIgG levels compared to single agent treatment or vehicle alone. The markedly improved anti-MM effects of the combination of bortezomib and anti-VEGF antibody compared to single agent treatment in this in vivo study of human MM is promising, and these results have provided the preclinical rationale for an ongoing randomized multi-center Phase II trial.

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