RESUMEN
In a two-year-old girl suffering from myositis ossificans progressiva a biopsy specimen from a soft tissue tumor was examined by electron microscopy and by collagen electrophoresis (SDS-Polyacrylamide Gel Electrophoresis). Electron microscopic findings of the biopsy specimen showed that the collagen appeared to be similar to type II collagen which can be found for example in hyaline cartilage however collagen electrophoresis revealed neither any certain signs of type II collagen nor any different proportion of type I and type III collagen compared to a healthy child.
Asunto(s)
Miositis Osificante/patología , Biopsia , Colágeno/análisis , Tejido Conectivo/ultraestructura , Femenino , Humanos , Lactante , Microscopía ElectrónicaRESUMEN
Dermatosparactic calf-tail-tendon-collagen was investigated by mechanical measurements, electron microscopy and x-ray diffraction. We suppose, that the tensile strength decrease of the fibres is due to the irregular aggregation of subfibrils to fibrils. The x-ray diagram of the fibre is not influenced by state of disorder. Cyclic extension of dermatosparactic collagen leads to a higher increase in tensile strength than in the case of normal calf tendon. The effect might be due to the increase of fibril- and area-density resulting in an augmentation of crosslinks.
Asunto(s)
Enfermedades del Colágeno/veterinaria , Colágeno , Tendones/análisis , Animales , Bovinos , Enfermedades de los Bovinos , Sustancias Macromoleculares , Microscopía Electrónica , Conformación Proteica , Enfermedades de la Piel/veterinaria , Difracción de Rayos XRESUMEN
The content of trace elements in several organs of rats under the influence of D-penicillamine (D-PA) was investigated by the neutronactivation-analysis. It could be shown an diminution of Cu, and Co under D-PA-treatment, the content of Fe, Mn, Rb and Zn was not influenced. The investigated organs didn't show any submicroscopic alterations under D-PA. On isolated collagen fibrils of tail tendon was seen a significantly diminuition of E-moduls. In accordance with Siegel the principal effect of D-PA is thought to block the synthesis of functional groups from Schiff-base crosslink precursors but not to inhibit lysyloxidase by loss of Cu-ions of connective tissue. The thermostability of D-PA influenced fibrils is changed in stretched state only and will be due to the lack of crosslink Schiff-bases; where as the shrinking point of not stretched fibrils shows only aging dependent changes.
Asunto(s)
Colágeno/metabolismo , Penicilamina/farmacología , Oligoelementos/metabolismo , Animales , Encéfalo/metabolismo , Cobalto/metabolismo , Cobre/metabolismo , Riñón/metabolismo , Hígado/metabolismo , Masculino , Miocardio/metabolismo , Ratas , Distribución TisularRESUMEN
The affect of stretch on collagen was investigated. Alterations of mechanical dimensions and thermostability of fibrils were measured and changes in fine structure determined by x-ray diffraction and electronmicroscopy. Collagen underwent changes both in tensile strength and fine structure following stretch beyond the physiological range. The severity of these changes depended both on the degree of stretch and the cross-link density of the collagen Fibrils either became split into bundles consisting of subfibrillar units or showed circumscribed kinking deformities. The mechanism producing kinking was investigated. It is possible that a connection exists between fibrillar kinking and tendon rupture.
Asunto(s)
Colágeno , Estrés Mecánico , Animales , Microscopía Electrónica , Ratas , Rotura , Cola (estructura animal)/lesiones , Temperatura , Traumatismos de los Tendones/fisiopatología , Tendones/ultraestructuraRESUMEN
Changes in the large periodic structure of collagen were investigated with the aid of synchrotron radiation. Following results were obtained: 1) Macroscopic extension results in elastic deformation of the elements which are determinant for the structure. 2) The increase of the large period is not proportional to the macroscopic stress. 3) The interpretation of these facts requires a mechanical coupling between the structural units. Up to extensions of 4% this coupling is produced by means of a viscoelastic matrix. 4) In all probability the polypeptide helices are deformed in an inhomogeneous mode. The results were set against measurements on human tendon and on artificially crosslinked collagen. The relations between the mechanical behaviour and the change of the large period were compared with the properties of a mathematical model.
Asunto(s)
Colágeno , Animales , Elasticidad , Conformación Proteica , Ratas , Difracción de Rayos XRESUMEN
Areas of disordered fibrillar structure similar to kinking deformities have been observed in specimens from ruptured tendons. It seems possible to compare this phenomenon with experimentally produced deformations. The significance for the pathomechanics of tendon rupture is discussed.