Biomechanics of the lung parenchyma: critical roles of collagen and mechanical forces

2005 ◽  
Vol 98 (5) ◽  
pp. 1892-1899 ◽  
Author(s):  
Béla Suki ◽  
Satoru Ito ◽  
Dimitrije Stamenović ◽  
Kenneth R. Lutchen ◽  
Edward P. Ingenito
Keyword(s):  
Mechanical Properties ◽  
Connective Tissue ◽  
Large Scale ◽  
Structural Integrity ◽  
Lung Parenchyma ◽  
The Body ◽  
Biological Macromolecules ◽  
Mechanical Forces ◽  
Connective Tissues ◽  
Architectural Organization

The biomechanical properties of connective tissues play fundamental roles in how mechanical interactions of the body with its environment produce physical forces at the cellular level. It is now recognized that mechanical interactions between cells and the extracellular matrix (ECM) have major regulatory effects on cellular physiology and cell-cycle kinetics that can lead to the reorganization and remodeling of the ECM. The connective tissues are composed of cells and the ECM, which includes water and a variety of biological macromolecules. The macromolecules that are most important in determining the mechanical properties of these tissues are collagen, elastin, and proteoglycans. Among these macromolecules, the most abundant and perhaps most critical for structural integrity is collagen. In this review, we examine how mechanical forces affect the physiological functioning of the lung parenchyma, with special emphasis on the role of collagen. First, we overview the composition of the connective tissue of the lung and their complex structural organization. We then describe how mechanical properties of the parenchyma arise from its composition as well as from the architectural organization of the connective tissue. We argue that, because collagen is the most important load-bearing component of the parenchymal connective tissue, it is also critical in determining the homeostasis and cellular responses to injury. Finally, we overview the interactions between the parenchymal collagen network and cellular remodeling and speculate how mechanotransduction might contribute to disease propagation and the development of small- and large-scale heterogeneities with implications to impaired lung function in emphysema.

Autoimmune connective tissue diseases

2013 ◽  
Vol 6 (3) ◽  
pp. 159-171
Author(s):  
Ishita Patel ◽  
Alia Ahmed
Keyword(s):  
Primary Care ◽  
Connective Tissue ◽  
Connective Tissue Diseases ◽  
The Body ◽  
Diverse Group ◽  
Connective Tissues

Connective tissue diseases are a rare and diverse group of disorders that result in pathology of the connective tissues of the body. This article focuses on the systemic autoimmune connective tissue diseases, and aims to provide a practical overview of these conditions for use in primary care.

Advanced Constitutive Model for the Accurate Evaluation of the Structural Performance of Welded Pipes in Offshore Applications

2018 ◽  
Author(s):  
Steven Cooreman ◽  
Dennis Van Hoecke ◽  
Martin Liebeherr ◽  
Philippe Thibaux ◽  
Hervé Luccioni
Keyword(s):  
Mechanical Properties ◽  
Constitutive Model ◽  
Large Scale ◽  
Structural Integrity ◽  
Compressive Strain ◽  
Longitudinal Direction ◽  
Structural Performance ◽  
Isotropic Hardening ◽  
Hardening Models ◽  
Strain Paths

To guarantee the structural integrity of oil and gas transporting pipelines, a detailed analysis of the pipe’s structural response has to be performed. This is of particular importance for offshore applications. As large scale testing is costly and time consuming, one often relies on FE (Finite Element) modelling to accomplish, at least, part of this task. Properties that typically need to be evaluated are compressive strain capacity, collapse resistance and ovalization during reel-lay installation. Furthermore, it can be assumed that those properties are influenced by the pipe forming process, as pipe forming will change the mechanical properties and the level of anisotropy and will modify/introduce residual stresses. Therefore, a first logical step is to simulate pipe forming before evaluating the pipe’s structural performance, to account for these effects. The reliability of FE simulations largely depends on the capability of the constitutive model to accurately describe the mechanical behaviour of the material being studied. Most commercial FE codes only offer combined kinematic-isotropic hardening models. Those models cannot capture the so-called cross-hardening effect and can therefore not predict the evolution of anisotropy during pipe forming. The present paper discusses the implementation and calibration of a more advanced constitutive model, more specifically the Levkovitch-Svendsen model, which accounts for isotropic, kinematic and distortional hardening. The model was implemented in Abaqus/Implicit through a UMAT user subroutine. An inverse modelling approach was applied to calibrate the constitutive model, whereby an extensive set of mechanical tests, involving cyclic tension-compression tests and tests with changing strain paths, was conducted. To assess the model’s performance, it was used in two case studies. The first study focused on the evolution of mechanical properties during spiral pipe forming. The results show that the Levkovitch-Svendsen model allows prediction of the properties in both the transverse and longitudinal direction on pipe. When applying a kinematic-isotropic hardening law only, the properties in the longitudinal direction are significantly underestimated. In the second study, different hardening models were used to predict the evolution of ovality during reel-lay installation. It was observed that the predictions made with the Levkovitch-Svendsen model were much closer to the experimental values than the results obtained by means of a kinematic-isotropic hardening model.

scholarly journals Sequential tendon ruptures in ochronosis: case report

2017 ◽  
Vol 3 (6) ◽  
pp. 1235
Author(s):  
E. G. Mohan Kumar ◽  
G. M. Yathisha Kumar
Keyword(s):  
Connective Tissue ◽  
Case Reports ◽  
Autosomal Recessive Disorder ◽  
Degradation Pathway ◽  
Homogentisic Acid ◽  
The Body ◽  
Acid Oxidase ◽  
Connective Tissues ◽  
Dark Pigmentation ◽  
Tendon Ruptures

<p>Alkaptonuria is a rare autosomal recessive disorder characterised by the absence of homogentisic acid oxidase, due to deficiency of an enzyme that degrades HGA in the tyrosine degradation pathway. Homogentisic acid (HGA) and its metabolites accumulate in the connective tissues leading to dark pigmentation of connective tissue in patients with alkaptonuria. HGA deposits in connective tissue causes weakness of the tendon and subsequent rupture, especially the large tendons in the body. Only few cases are reported in the literature with multiple tendon rupture but many case reports are available with isolated rupture of tendons. We report on a patient with sequential tendon ruptures in a patient. The case is reported for its rarity.</p>

Mechanical Properties of the Porcine Lens Capsule

2008 ◽  
Author(s):  
Rouzbeh Amini ◽  
Alina Oltean ◽  
Vincent Barnett ◽  
Yoav Segal ◽  
Victor H. Barocas
Keyword(s):  
Mechanical Properties ◽  
Basement Membrane ◽  
Large Scale ◽  
Genetic Disorders ◽  
Genetic Mutation ◽  
Mechanical Tests ◽  
Lens Capsule ◽  
Basement Membranes ◽  
The Body ◽  
Ocular Abnormalities

Basement membranes are ubiquitous. In humans, genetic disorders in basement membranes can lead to many complications including kidney disease, skeletal muscle myopathy, hearing loss, and ocular abnormalities[1]. We hypothesize that genetic mutation of the microstructure of the lens capsule basement membrane will alter its mechanical properties. Because of its unique thickness and anatomically distinct margins, the lens capsule is the only site in the body where large-scale mechanical tests on the basement membrane can be made.

Applications of atomic force microscopy in modern biology

2021 ◽  
Author(s):  
Tathagata Nandi ◽  
Sri Rama Koti Ainavarapu
Keyword(s):  
Mechanical Properties ◽  
Single Molecule ◽  
Cancer Biology ◽  
Biological Macromolecules ◽  
Mechanical Forces ◽  
Dynamic Simulations ◽  
Modern Biology ◽  
Imaging Tool ◽  
Atomic Force ◽  
Computer Based

Single-molecule force spectroscopy (SMFS) is an emerging tool to investigate mechanical properties of biomolecules and their responses to mechanical forces, and one of the most-used techniques for mechanical manipulation is the atomic force microscope (AFM). AFM was invented as an imaging tool which can be used to image biomolecules in sub-molecular resolution in physiological conditions. It can also be used as a molecular force probe for applying mechanical forces on biomolecules. In this brief review, we will provide exciting examples from recent literature which show how the advances in AFM have enabled us to gain deep insights into mechanical properties and mechanobiology of biomolecules. AFM has been applied to study mechanical properties of cells, tissues, microorganisms, viruses as well as biological macromolecules such as proteins. It has found applications in biomedical fields like cancer biology, where it has been used both in the diagnostic phases as well as drug discovery. AFM has been able to answer questions pertaining to mechanosensing by neurons, and mechanical changes in viruses during infection by the viral particles as well as the fundamental processes such as cell division. Fundamental questions related to protein folding have also been answered by SMFS like determination of energy landscape properties of variety of proteins and their correlation with their biological functions. A multipronged approach is needed to diversify the research, as a combination with optical spectroscopy and computer-based steered molecular dynamic simulations along with SMFS can help us gain further insights into the field of biophysics and modern biology.

scholarly journals ANATOMICAL BASIS OF BIOMECHANICAL PROPERTIES OF SUPERFICIAL TISSUES OF THE ANTERIOR ABDOMINAL WALL

2020 ◽  
Vol 20 (4) ◽  
pp. 198-203
Author(s):  
V.S. Drabovskiy ◽  
N.R. Kerbazh ◽  
A.K. Akeyshi ◽  
Ya.V. Rybalka
Keyword(s):  
Mechanical Properties ◽  
Connective Tissue ◽  
Abdominal Wall ◽  
Prolonged Exposure ◽  
The Body ◽  
Histological Structure ◽  
Rapid Weight Loss ◽  
Anatomical Basis ◽  
Deformation Properties ◽  
Mechanical Factors

Biomechanics is a science that studies the mechanical properties of tissues, individual organs and systems and the body as a whole. The unique mechanical properties of the skin provide the function of support and protection of internal organs through the skin mobility and elasticity. This feature of the skin is determined by its microstructural organization and arrangement of connective tissue fibres. The mechanical properties of the skin are mainly determined by the collagen-rich dermis. The mechanics of the dermis, in turn, depends on the structure, density and direction of collagen fibres. Each biological tissue is able to acquire deformation properties i.e. stretching or contraction. At each stage of deformation in the tissues of different topographic and anatomical areas there are changes in histoarchitectonics (within the plastic characteristics, and outside these parameters). Different structural interactions are expressed by different mechanical factors, which are adequate to the magnitude and direction of tensile forces (deformation vectors), form the typical features of the connective tissue matrix of abdominal wall tissues. Normalization of the direction of tissue stress vectors, uniform distribution of the direction and force of deformation prevent microstructural rearrangement of the surface tissues of the abdominal wall. Dynamic changes in the histological structure and biomechanical behaviour of the skin are closely related to the aging process, hormonal background, mechanical factors: physiological stretching of the skin during rapid growth in adolescence, pregnancy, overweight (or rapid weight loss), under the influence of physical load and wound healing. All these factors lead to connective tissue remodelling. Thus, the skin has a complex three-dimensional morphological structure; it is subjected to prolonged exposure to internal and external factors that determines its mechanical properties.

scholarly journals KOMPONEN SEL JARINGAN IKAT

2014 ◽  
Vol 6 (3) ◽  
Author(s):  
Sunny Wangko ◽  
Ronny Karundeng
Keyword(s):  
Connective Tissue ◽  
Special Functions ◽  
The Body ◽  
Main Function ◽  
Connective Tissues ◽  
Intercellular Matrix ◽  
Tissue Cells ◽  
General Difference

Abstract: Connective tissue is distributed in all parts of the body and its main function is to connect cells and tissues. Most of the embryonic connective tissues are derived from embryonal messenchymal tissues. There are a variety of connective tissues which are compatible with their functions and locations. The general difference of all connective tissues is the arrangement and composition of intercellular matrix. Connective tissues are composed of two major components: cells and intercellular matrices. Connective tissue cells, fixed cells or wandering cells, have their special functions which support each other to maintain the optimal histophysiology of the connective tissue.Keywords: connective tissues, cells, histophysiologyAbstrak: Jaringan ikat tersebar luas di seluruh bagian tubuh dengan fungsi utama untuk menghubungkan berbagai komponen sel atau jaringan. Hampir seluruh jaringan ikat embriologik berasal dari jaringan mesensimal embrional. Terdapat berbagai jenis jaringan ikat yang sesuai dengan fungsi dan lokasinya. Perbedaan utama dari berjenis-jenis jaringan ikat tersebut berdasarkan susunan dan komposisi matriks intersel. Jaringan ikat terdiri dari dua komponen dasar utama yaitu sel dan matriks intersel. Sel-sel jaringan ikat baik yang tetap maupun yang bebas mempunyai fungsi khusus masing-masing yang saling melengkapi untuk mempertahankan keutuhan histofisiologi jaringan ikat.Kata kunci: jaringan ikat, sel, histofisiologi

scholarly journals VITAL STAINING OF THE CONNECTIVE TISSUES

1938 ◽  
Vol 68 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Lester S. King
Keyword(s):  
Connective Tissue ◽  
Trypan Blue ◽  
Vital Staining ◽  
The Body ◽  
Elastic Fibers ◽  
Blue Color ◽  
Connective Tissues ◽  
Connective Tissue Matrix ◽  
Tissue Matrix ◽  
Special Case

Trypan blue injected intravenously is bound almost at once by the intercellular connective tissue elements all over the body,—by collagen, reticulin, and elastic fibers. This union of dye and tissue elements is the factor responsible for the early macroscopic blue color and is antecedent to cellular colloidopexic action. Different examples of connective tissue differ among themselves in their ability to hold the dye. Diffuse staining of elastic fibers noted by previous observers is merely a special case of the general affinity of connective tissue for the dye. The evidence suggests that the histiocytes are cells specialized to segregate noxae that become diffusely bound to the intercellular connective tissue matrix.

scholarly journals In Vitro Measurements of Cellular Forces and their Importance in the Lung—From the Sub- to the Multicellular Scale

Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 691
Author(s):  
Peter Kolb ◽  
Annika Schundner ◽  
Manfred Frick ◽  
Kay-E. Gottschalk
Keyword(s):  
Mechanical Properties ◽  
Measurement Techniques ◽  
Short Review ◽  
Cellular Level ◽  
The Body ◽  
Mechanical Forces ◽  
Mechanical Stimuli ◽  
Length Scales ◽  
Cellular Forces

Throughout life, the body is subjected to various mechanical forces on the organ, tissue, and cellular level. Mechanical stimuli are essential for organ development and function. One organ whose function depends on the tightly connected interplay between mechanical cell properties, biochemical signaling, and external forces is the lung. However, altered mechanical properties or excessive mechanical forces can also drive the onset and progression of severe pulmonary diseases. Characterizing the mechanical properties and forces that affect cell and tissue function is therefore necessary for understanding physiological and pathophysiological mechanisms. In recent years, multiple methods have been developed for cellular force measurements at multiple length scales, from subcellular forces to measuring the collective behavior of heterogeneous cellular networks. In this short review, we give a brief overview of the mechanical forces at play on the cellular level in the lung. We then focus on the technological aspects of measuring cellular forces at many length scales. We describe tools with a subcellular resolution and elaborate measurement techniques for collective multicellular units. Many of the technologies described are by no means restricted to lung research and have already been applied successfully to cells from various other tissues. However, integrating the knowledge gained from these multi-scale measurements in a unifying framework is still a major future challenge.

Banded Structures in the Connective Tissue of Meningioma

1976 ◽  
Vol 34 ◽  
pp. 234-235
Author(s):  
C. N. Sun ◽  
H. J. White
Keyword(s):  
Connective Tissue ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Collagen Fibrils ◽  
Lead Citrate ◽  
Connective Tissues ◽  
Native Collagen ◽  
Routine Procedures

Previously, we have reported on extracellular cross-striated banded structures in human connective tissues of a variety of organs (1). Since then, more material has been examined and other techniques applied. Recently, we studied a fibrocytic meningioma of the falx. After the specimen was fixed in 4% buffered glutaraldehyde and post-fixed in 1% buffered osmium tetroxide, other routine procedures were followed for embedding in Epon 812. Sections were stained with uranyl acetate and lead citrate. There were numerous cross striated banded structures in aggregated bundle forms found in the connecfive tissue of the tumor. The banded material has a periodicity of about 450 Å and where it assumes a filamentous arrangement, appears to be about 800 Å in diameter. In comparison with the vicinal native collagen fibrils, the banded material Is sometimes about twice the diameter of native collagen.

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