Heart valve prostheses are used to replace native heart valves which that are damaged because of congenital diseases or due to ageing. Biological prostheses made of bovine pericardium are similar to native valves and do not require any anticoagulation treatment, but are less durable than mechanical prostheses and usually fail by tearing. Researches are oriented in improving the resistance and d...

The effects of the release of normal distractive forces from the rabbit's tendo-achilles by distal tenotomy and proximal sciatic neurectomy alone, and in combination, have been studied. The results demonstrate that: 1. Complete release of distractive forces from the tendon is followed by changes in collagenous architecture and an increase in cell size and cell population, particularly at the mu...

Few previous studies have been made of the appearance of articular cartilage under the electron microscope. Cameron and Robinson (1958) examined the matrix of both articular and epiphysial cartilages in femora of infants who had died in the neonatal period. No observations were made upon the cells as they were unable to assess the extent of post mortem change. They described the presence in the...

Tengroth and Ammitzböll found the collagen content of the optic disc in glaucoma to differ from that of normal eyes. A theory was advanced that a primary collagen disturbance might be involved in the pathogenesis of glaucoma. The connective tissue in the body has a supportive function in almost all the organs. The tensile strength and elasticity of connective tissue is mainly due to the presenc...

Neutrophil granulocytes (PMNs) adhere poorly to and are unable to locomote on collagen-coated glass; they are able to attach to and invade three-dimensional matrices of collagen fibres. Invasion is largely independent of adhesion to the fibres, does not occur by proteolysis of the gel, and is not affected by the presence of fibronectin or chondroitin sulphate. Invasion is reduced by increasing ...

An in vitro morphological study on the relation of the stress field and the orientation of cells with the use of the time lapse video recording system was carried out. Specimens of thin collagen gel membrane, within which cells are proliferating, were examined under various mechanical conditions. Cell stretching, cell orientation, cell migration, cell proliferation and generation of tensile str...

Bone samples from the iliac crest of patients with no signs of bone disorder were treated with collagenase to remove the collagen component and so allow detailed observation of the mineral hydroxyapatite. Both polished and unpolished surfaces were studied in the scanning electron microscope and they showed that the mineral component of bone is composed of small rounded units about 10 nm across ...

Electron microscopic findings of the skin biopsy of a boy with spondyloepiphyseal dysplasia tarda showed several novel features. The basement membrane of the epidermis showed focal irregular thickening and reduplication. The collagen fibres showed foci of fibrous long spacing collagen and marked variation in fibre diameter. Taken together these abnormalities have not been reported in any other ...

BACKGROUND Computational models of Achilles tendons can help understanding how healthy tendons are affected by repetitive loading and how the different tissue constituents contribute to the tendon's biomechanical response. However, available models of Achilles tendon are limited in their description of the hierarchical multi-structural composition of the tissue. This study hypothesised that a p...

SUMMARY Post-mortem specimens taken from the antebrachial and brachial fasciae of 20 upper limbs were studied by histological and immunohistochemical staining in order to evaluate collagen fibre bundle arrangement, the presence of elastic fibres, and the density of innervation in deep muscular fascia. The study demonstrated that the fasciae are formed of numerous layers of undulating colla-gen ...