Ultrastructural changes in the synovial membrane in lipohaemarthrosis

Images

SURFACE ULTRASTRUCTURE OF MATURE ADULT HUMAN ARTICULAR CARTILAGE

1. The surface of mature adult human articular cartilage from the knee has been studied by electron microscopy in eleven patients ranging in age from thirty-seven to eighty-three years. The ultrastructural appearance varies from person to person and often from area to area in the same specimen. These variations range from an intact surface to one showing overt fibrillation visible with the light microscope.

2. In areas where the articular surface appears intact the underlying superficial matrix consists of closely packed collagen fibres with only a small amount of interfibrillary ground substance. The collagen fibres show a predominantly tangential orientation in this region of the cartilage. Osmophilic lipidic bodies are sometimes seen in the matrix very close to the joint surface.

3. The appearances under the electron microscope are altered in what is interpreted as an early ultrastructural change in the development of cartilage fibrillation. In the affected areas the collagen fibres show abnormally wide separation by an excessive amount of interfibrillary matrix. Collagen fibres become directly exposed to the joint cavity, and the surface can also show accumulations of finely granular material and sometimes tuft-like projections containing collagen fibres and fine fibrils. At a slightly later stage shallow clefts and steeply sloping curves are apparent at the surface. It is suggested that these various alterations precede the development of overt fibrillation visible under the light microscope.

4. Electron micrographs occasionally show small "blisters" at the articular surface. Electron microscopy has not given evidence of shedding of cells into the joint cavity from non-fibrillated areas of adult human articular cartilage. Cells can, however, sometimes become exposed at the surface in fibrillated areas.

Synovial membrane in experimentally-produced chronic haemarthrosis

Images

Electron microscopic observations on the virus particles in Herpes simplex encephalitis

Cerebral cortex from eight fatal cases of Herpes simplex encephalitis has been studied by electron microscopy. The diagnosis had been based on clinical findings, necropsy evidence of bitemporal necrosis, and histological confirmation of intranuclear inclusions with a lymphocytic inflammatory response, even though virus cultures were unsuccessful. Virus particles were seen predominantly in nuclei in six of these cases, utilizing tissue which had been preserved in formalin for up to four years or had been embedded in paraffin. Although demonstration of these particles is only indicative of the herpes group and not specifically of Herpes simplex, electron microscopy of either biopsy or postmortem material may be a useful adjunct in making the diagnosis and can be accomplished before virological studies have been completed.

Chondrocyte ultrastructure in adult human articular cartilage

Images

Ultrastructure of synovial membrane in osteo-arthritis

Images

Ultrastructure of synovial membrane in rheumatoid arthritis

Images