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Biomedical subjects

M F Neurath

Publications and source records attributed to M F Neurath.

96 records · Page 6Linked to original sources
PubMed1993

Ultrastructural causes of rupture of hand tendons in patients with rheumatoid arthritis. A transmission and scanning electron microscopic study.

To identify the cause of rupture of hand tendons in patients with rheumatoid arthritis, we studied the underlying ultrastructural changes of the collagenous fibril systems. Samples of the flexor digitorum superficialis (n = 12) and the extensor digitorum communis (n = 20) were taken during tenosynovectomy. Tendons dissected at necropsy (n = 30) served as controls. Specimens were analysed by transmission and scanning electron microscopy. Interfibrillar dysplastic fibrils, "Luse bodies", and intracellular collagen were found in rheumatoid tissues. The diameters of collagen fibrils were significantly reduced compared with the control group (p < 0.01). The duration of the disease usually correlated well with the ultrastructural collagenous lesions. To provide optimum conditions for restoration of rheumatoid hand tendons, early synovectomy in rheumatoid patients seems warranted from the ultrastructural point of view. The alterations in collagen may explain the inadequate function of the hand tendons in patients with rheumatoid arthritis.

Arthritis, Rheumatoid↗
PubMed1992

Structure and function of matrix components in the cruciate ligaments. An immunohistochemical, electron-microscopic, and immunoelectron-microscopic study.

In the present study, the matrix components of 100 cruciate ligaments were analyzed by conventional electron microscopy, immunohistology, morphometry, and immunoelectron microscopy. The anterior (ACL) and the posterior (PCL) cruciate ligaments contained collagen types III, IV, and VI. Several structural glycoproteins, like fibronectin, laminin, entactin, tenascin, and undulin were detected using monoclonal antibodies. Whereas laminin and entactin were higher concentrated in the PCL, type VI collagen was more frequently found in the ACL. The ACL had a critical nourishment in its distal and middle thirds. In all ligament parts the PCL revealed a better vascular supply with strong correlation to type IV collagen expression. The normal matrix of the cruciate ligaments represented a complicated regulatory network of proteins, glycoproteins, elastic systems, and glycosaminoglycans with multiple functional interactions.

Adolescent↗
PubMed1992

Collagen ultrastructure in ruptured cruciate ligaments. An electron microscopic investigation.

The ultrastructure of collagen fibrils was investigated in normal (n 39) and ruptured (n 23) human anterior cruciate ligaments. The normal ligament had a complex three-dimensional structure. Collagen fibrils predominantly had a undirectional course with parallel arrangement and a mean diameter of 75 (20-185) nm. Four days after anterior cruciate ligament rupture, the mean fibril diameter was increased; it later decreased, probably due to synthesis of young, thin 30-40 nm fibrils. Interfibrillar dysplastic collagen fibrils were detected in the extracellular matrix of ruptured ligaments. They were more frequently found later than 3 days after rupture and were seen also at a distance of 2-3 cm from the rupture zone. The presence of dysplastic fibrils may explain the functional insufficiency of the repair tissue in ruptured cruciate ligaments.

Adolescent↗
PubMed1992

[Ultrastructure of the long flexor and extensor tendons of the hand in rheumatic tenosynovitis].

Tendon ruptures are a frequent problem in patients affected by rheumatoid arthritis. The aim of the present study was to further characterize the known macroscopic changes of tendon tissue by micromorphological methods. Flexor and extensor tendon samples (n = 28) in rheumatoid arthritis were investigated by light- and transmission electron microscopy. In all cases, marked alterations in fibril architecture and structure were found. The fibril diameter showed a higher variability (range = 20-490 nm, x = 98.9 nm, s = 49.1 nm) in comparison with the control group of normal tendons (range = 20-290 nm, x = 119.0 nm, s = 34.9 nm). The average distance between the major bands in rheumatoid arthritis was reduced (from 57.3 nm down to 54.8 nm). Rare minor bands were detected. Oxytalan and mature elastic fibres were destroyed. These findings suggest that a causal correlation exists between altered matrix substructure and insufficient function of the tendon tissue in rheumatoid arthritis.

Adult↗