Although the aetiology of Williams syndrome (WS) is related to elastin gene disruption, its pathogenesis remains unknown, particularly that of vascular lesions. The aim of the present study was to compare the elastic properties of three WS patients with age- and gender-matched normotensive and hypertensive controls. Common carotid arteries of WS patients had a higher distensibility, a thicker i...

Alveolar elastic fibres are key targets of proteases during the pathogenesis of chronic obstructive pulmonary disease (COPD). In the current study, we hypothesised that a response to injury leads to enhanced alveolar elastin gene expression in very severe COPD. Lung samples obtained from 43 patients, including 11 with very severe COPD (stage 4), 10 donors, 10 with moderate/severe COPD (stage 2-...

Soft tissues exhibit a nonlinear, essentially incompressible (visco-) elastic response; a key issue is the active nature of muscle fibres, in other words their ability to contract and relax in response to biochemical signals. Here we present a continuum model able to describe an active elastic medium.

The remarkable elastic behaviour of the lung entails both continuous tissue stress and a cyclic stress produced by the fluctuating difference between intrathoracic and intra-alveolar pressures throughout the entire span of life. In spite of these potentially disruptive forces, lung structure is preserved by the fibrous connective-tissue proteinscollagen, elastin, and reticulin. These extracellu...

This paper describes a new method for modelling paper strength and elastic properties by analysing the force distribution along single half fibres in the network. Paper mechanical properties are modelled from the point of view of single fibres of interest. Each half fibre of interest is in contact with i other crossing fibres, which connect to the network. A strain, ε , is applied to the networ...

We investigate the dynamics of a flexible, elastic fibre, suspended in a fluid and subjected to a 3D shear flow. Simulations are performed using the “Immersed Boundary Method,” and are distinguished by their ability to capture the hydrodynamic interaction between the fluid and fibre, as well as the detailed structure of the individual fibres. Suspensions of flexible fibres are encountered in ma...

A new analytical solution for the load distribution along a fibre in a network has been used to investigate some aspects of paper tensile strength and elastic modulus. The method uses a similar approximation to the shear-lag formulation but allows stress transfer at individual contacts, rather than specifying a single stress transfer function applying along the entire length of the fibre. Measu...

Background—Lysozyme is increased in inflammatory reactions and is a component of the extracellular matrix, but its possible role in lung diseases such as emphysema and interstitial fibrosis has not been investigated. Methods—To characterise diVerences in lysozyme content among normal, emphysematous, and fibrotic human lungs, tissue sections obtained from necropsy specimens were immunostained wi...

There is an intimate relationship between the extracellular matrix (ECM) and smooth muscle cells within the airways. Few studies have comprehensively assessed the composition of different ECM components and its regulators within the airway smooth muscle (ASM) in asthma. With the aid of image analysis, the fractional areas of total collagen and elastic fibres were quantified within the ASM of 35...

Pseudoxanthoma elasticum (PXE) is a heritable disorder of connective tissue, affecting mainly skin, eye and the cardiovascular system. PXE is characterized by dystrophic mineralization of elastic fibres. The condition is caused by loss of function mutations in ABCC6. We generated Abcc6 deficient mice (Abcc6-/-) by conventional gene targeting. As shown by light and electron microscopy Abcc6-/- m...