BackgroundIn this study, we evaluated the changes which occurred in the epiligament, an enveloping tissue of the ligament, during the ligament healing. We assessed the association of epiligament elements that could be involved in ligament healing.MethodsThirty-two 8-month old male Wistar rats were used in this study. In twenty-four of them the lateral collateral ligament of the knee joint was surgically transected and was allowed to heal spontaneously. The evaluation of the epiligament healing included light microscopy and transmission electron microscopy.ResultsAt the eight, sixteenth and thirtieth day after injury, the animals were sacrificed and the ligaments were examined. Our results revealed that on the eight and sixteenth day post-injury the epiligament tissue is not completely regenerated. Till the thirtieth day after injury the epiligament is similar to normal, but not fully restored.ConclusionOur study offered a more complete description of the epiligament healing process and defined its important role in ligament healing. Thus, we provided a base for new strategies in ligament treatment.

Our results indicate that intraviterally administered Avastin causes changes in the new vessel walls and in the extracellular matrix components. It diminishes the fenestration of the endothelial cells but also increases the risk of vessel occlusions and may have an alterating effect on the RPE cells. Although Avastin has the potential to improve the quality of life, patients subjected to the treatment should be carefully selected and constantly monitored.

The occasional humeral growth retardation or premature closure of the growth plate medially, documented among more than 120 solitary bone cysts reviewed, was reason to undertake a thorough study of the growth plate in the area of the cyst. The findings in the hyaline zone disclose a considerable number of vessels and slits of the cartilage that are broadened toward the proliferative and hypertrophic zones. In some places they communicate with the vessels or are lined with endothelium. Ultrastructurally, changes of a destructive nature are disclosed, involving the growth plate zone and corresponding to the most active metabolic processes. In the altered chondrocytes substantial increases in glycogen granules and lipid droplets are observed, as well as reduction of the cellular organelles. In rather severely affected cells changes in the nuclei, lysosomal structures, and myelin-like lamellar bodies are established. The disappearance of cellular organelles and the fragmentation of cytoplasm are interpreted as a final phase of the above-listed changes. In conclusion, the cyst is considered a probable primary cause of the changes described.

Our results point out that blood in the vitreous cavity alters the ultrastructure of the existing PDR proliferations in respect to making them more rigid and prone to contractions. It is therefore important to consider vitreous haemorrhage in PDR patients as a very serious complication, requiring in some cases urgent vitreo-retinal surgery.

We studied the ultrastructural changes that take place in the transitional zone between the articular cartilage and the synovial membrane during the development of experimental osteoarthrosis. We focused special attention on changes involving the proteoglycan complexes within the matrix of articular cartilage. We observed that changes in the transitional zone resemble those seen in articular cartilage during the development of osteoarthrosis. We also found transient cellular forms with fibroblast phenotype regulating the demands of both cartilage and synovial matrix. The transient nature of these elements determines the pronounced lability of this zone, and this may be related to the early development of osteoarthrosis.Résumé Nous avons étudié les changements ultrastructuraux dans la zone transitionnelle entre le cartilage articulaire et la synoviale pendant le développement dune arthrose expérimentale. Une attention spéciale a été accordée aux altérations des complexes de protéoglycans dans la matrice du cartilage articulaire. Nous avons observé que les changements dans la zone transitionnelle ressemblent à ceux du cartilage articulaire pendant le développement de l'arthrose. Nous avons trouvé des formes cellulaires transitoires avec un phénotype de fibroblaste qui règle les demandes du cartilage et de la matrice synoviale. La nature transitoire de ces éléments détermine la labilité prononcée de cette zone qui est la cause sous-jacente des premiers signes manifestes du développement de l'arthrose.