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Biomedical subjects

E Stofft

Publications and source records attributed to E Stofft.

At least 37 records · Page 2Linked to original sources
PubMed1992

[Fascicular and sub-fascicular architecture of the cruciate ligament].

The details of the collagen fascicle morphology and the vascularization of the anterior and the posterior cruciate ligament were examined by the combined use of histology, transmission- and scanning electron microscopy, morphometry and immunohistochemistry. The diameters of the collagenous fibrils in the anterior cruciate ligament ranged between 20 and 155 nm (x = 74 nm, s = 18.8 nm) and in the posterior cruciate ligament between 20 and 175 nm (x = 82 nm, s = 25.4 nm). Type III and VI collagen were found distributed throughout the matrix but concentrated in the attachment regions of the ligaments. The content of type IV collagen in the anterior cruciate ligament was low. The amount of arterioles revealed a typical pattern (anterior cruciate ligament: less than 30 years = 2.94/mm2, greater than 90 years = 2.02/mm2, proximal = 3.15/mm2, distal = 2.18/mm2; posterior cruciate ligament: less than 30 years = 4.69/mm2, greater than 90 years = 3.87/mm2, proximal = 4.08/mm2, distal = 3.98/mm2).

Adult↗
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

Morphological changes in the tracheal epithelium of guinea pigs in conditions of "marginal" vitamin A deficiency. A light, scanning- and transmission-electron microscopic study under special breeding conditions appropriate to early vitamin A deficiency.

The aim of the study was to find out the influence of marginal vitamin A deficiency on morphological structures in the tracheobronchial epithelium in guinea pigs. The tracheobronchial epithelium of animals with vitamin A deficiency (n = 15) and control animals (n = 7), kept under optimal laboratory conditions, was evaluated by light and electron microscopy. The cellular ultrastructure was morphometrically analyzed. The height of the respiratory epithelium was slightly increased. The basal cells were arranged in a loose cell band of three to four layers. The quantity of cytofilaments in their cytoplasm was enhanced. Goblet cells were significantly reduced in vitamin A deficiency. There was also a significant decrease in their secretory granules. The number of ciliated cells was almost unchanged. They showed a significant reduction in mitochondria. The kinocilia often contained an atypical structure of the microtubules. Our findings confirm multiple ultrastructural dysplasias in early vitamin A deficiency which may lead to a disturbance of mucociliary clearance.

Animals↗
PubMed1992

[New aspects of the functional anatomy of the menisci].

The present study concerned 16 human menisci: light, transmission (TEM) and scanning electron microscopic (SEM) techniques were used in addition to histochemical examinations, to define the microstructure of their collagenous fibre systems. A characteristic arrangement of the fibrils was noted. The diameters of the collagen fibrils ranged between 20 and 190 nm in the medial meniscus, the mean value being 67.5 nm (lateral: 70 nm). Many collagen type VI fibrils were detected, and collagen type IV was present. Such an organization has implications for knee joint stability, the variability of the fibril diameters and the characteristic arrangement giving the tissue great tensile stiffness and allows adaptation to all physiological loading conditions. On the surface of the menisci openings of canal-like structures were noted. Their characteristic distribution indicates that they carry nutrients from the synovial fluid to the normal avascular areas of the menisci.

Actin Cytoskeleton↗
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↗
PubMed1991

Demonstration of endogenous lectins in synovial tissue.

We have recently shown that synoviocytes and extracellular matrices exhibit distinct patterns of carbohydrate expression. Their biological relevance is however not known. The purpose of the present study was to find out whether human synovial tissue would also show a specific receptor pattern for complex sugar molecules. Endogenous lectins were displayed by means of biotinylated neoglycoproteins and sulfated polysaccharides in paraffin-embedded material or cryosections. In addition to certain carbohydrate components that are known to be constituents of the carbohydrate part of cellular glycoconjugates, our panel included heparin and fucoidan, a sulfated fucose. Binding sites were shown using the avidin-peroxidase technique for light microscopy. The results were compared with immunohistochemical methods and enzyme histochemistry. Our study demonstrates that human synovial tissue contains a complex pattern of endogenous lectins depending on the different types of synovitis. The staining method we used in the investigation allows for precise localization of saccharide binding receptors and is therefore believed to be a reliable technique for further phenotypic characterization of synovial cells.

Antibodies, Monoclonal↗
PubMed1991

[Comparative microstructural studies on collagen and elastic fiber systems of the cruciate ligaments].

The aim of the present study was to compare the collagenous fibre systems of the anterior (ACL) with the posterior cruciate ligament (PCL). 22 cruciate ligaments were examined by the combined use of light-, transmission- and scanning electron microscopy. Characteristic interligamental differences were established. ACL: more anchoring type VI collagen, thinner but more branched fibrils, complex collagen networks, much more elastic elements. PCL: more type IV collagen, many intrinsic vessels, thicker fibrils, parallel fibre arrangement. The results indicate that the ACL is exposed at the first line to rotational forces, the PCL probably more to tensional forces. The collagen fibre arrangement of the cruciate ligaments is to take into consideration by the surgeon.

Adult↗
PubMed1991

Cartilage changes in rats induced by papain and the influence of treatment with N-acetylglucosamine.

Cartilage damage in the knee joints of rats was induced with a single intraarticular injection of 10 mg papain. Such damage was indicated by a decrease in the content of glycosaminoglycans and histologically detectable alterations in the surface of patellar cartilage. Daily treatment of the rats with N-acetylglucosamine by gavage led to an increase of the glycosaminoglycans of the cartilage and of incorporation of the radioactive precursor of glycosaminoglycan synthesis, 3H-glucosamine hydrochloride, in comparison to control animals treated with saline. The incidence of pathological alterations of the cartilage in histological samples was reduced.

Acetylglucosamine↗
PubMed1990

Crystalloid lysozyme inclusions in Paneth cells of vitamin A-deficient rats.

The effect of vitamin A-deficiency on jejunal Paneth cells in rats was investigated. Crystalloid particles were observed in secretion granules of Paneth cells from 6 out of 8 rats with vitamin A-deficiency. The particles were similar to those found in Paneth cells under other experimental conditions. Using an immuno-electron-microscopic technique we demonstrated a clear lysozyme immunoreactivity of these particles. In 2 vitamin A-deficient rats tubular structures have been detected in addition to the crystalloid particles. Crystalloid particles or tubular structures were not detectable in a control group of 8 vitamin A-supplemented rats. The morphological alterations of Paneth cells may be correlated to an impaired local immunity of the intestine during vitamin A-deficiency.

Animals↗
PubMed1988

The lectin binding pattern of normal and pathologically altered synovial tissue.

Light-microscopical lectin-binding studies were carried out in healthy and pathologically altered synovial tissue (osteoarthrosis, rheumatoid arthritis (RA)). Seven lectins were studied: Con A, DBA, PNA, RCA, SBA, UEA-I, and WGA. Con A and WGA mark all lining cells and the majority of subintimal synovial cells. RCA and SBA stain only a portion of lining cells, regardless of the basic pathology. The lectin PNA reacts only with RA and arthrotic material, and is thus suitable for the diagnosis of inflammatory changes in synovial tissue. UEA-1 is a consistent marker for capillary endothelium and large vessels.

Arthritis, Rheumatoid↗
PubMed1987

[Scanning electron microscopy findings in a rigid one-piece polymethylmethacrylate anterior chamber lens with a 30 year duration in the eye].

A rigid one-piece PMMA anterior chamber lens (Scharf type) had to be removed 30 years after implantation because of diffuse bullous keratopathy and painful secondary glaucoma. Scanning electron microscopy showed the IOL to have a crater-like surface, while the haptics, having been in contact with intraocular tissues, were superficially and deeply eroded. Comparison with two identical anterior chamber lenses which had not been implanted revealed that the changes seen in the removed IOL must have been the result of degradation of the PMMA material.

Adult↗
PubMed1986

Vitamin A and ciliated cells. I. Respiratory epithelia.

To estimate the role of vitamin A on ciliated cells we investigated whether ciliated cells undergo any alteration during vitamin A deficiency. The epithelia examined include the ciliated cells of the respiratory tract and the ciliated sensory cells of the inner ear, the tongue, and the olfactory cells. This part of the paper will describe the ciliated epithelium of the tracheobronchial tract and its relation to vitamin A status. During vitamin A deficiency a partial loss of ciliae can be observed before any squamous metaplasia (which usually occurs during longer lasting vitamin A deficiency) develops. The scanning electron microscopic data illustrate the altered surface of the epithelium during vitamin A deficiency better than transmission electron microscopy.

Animals↗
PubMed1985

Development and morphology of rat synovial membrane.

The development of the knee joint and synovial membrane in Wistar rats was studied from the 13th fetal day until adulthood by means of light microscopy, transmission electron microscopy and scanning electron microscopy. Using acid phosphatase and peroxidase methods, the different cell types of synovial membrane could be identified.

Animals↗
PubMed1985

Vitamin A deficiency and sensory function.

Morphological investigation of tongue, olfactory epithelia, trachea and inner ear in vitamin A deficiency are reported. The results support assumptions concerning the loss of sensory function as been at least a secondary effect of alterations of the neighbourhood of the sensory cells caused by vitamin A deficiency. Taste buds are hindered in function by a dense layer of squamous cells and olfaction is decreased by atrophy of the surrounding respiratory epithelium. Inner ear functionality seems to be affected by vitamin A status via a stabilizing effect on the endolymph-perilymph barrier.

Animals↗