ABSTRACT
The cytoskeleton of the human osteoarthritic synovial lining cell (SLC) consists of an extensive number of vimentin intermediate filaments (IFs) in addition to microfilaments and microtubules. The IFs are especially prevalent in the SLC processes, but are commonly seen in a paranuclear arrangement. Processes, ending in numerous microvilli and blebs, project into the joint space. Scanning electron microscopy (SEM) further reveals the processes that may parallel the synovium surface for a short distance. IFs extend to the termination of such Numerous pinocytotic vesicles and extensive rough endoplasmic reticulum (rER) are characteristic of the type B cells. Lysosomes and long microvilli identify the type A cell. Punctate adherens, gap junctions, and cilia are the cell membrane specializations of the osteoarthritis (OA) synovium. A comparison with synovium from rheumatoid arthritis (RA) patients is made in order to assess the effect o this inflammatory disease on the SLC cytoskeleton, cell type relationship, and cell arrangement. The prominent cytoskeleton appears to play an important role in the architecture of the synovium. Our findings are further presented in the form of a drawing which in some aspects could describe the morphology of the normal synovium.
Subject(s)
Cytoskeleton/ultrastructure , Osteoarthritis/pathology , Synovial Membrane/cytology , Synovial Membrane/ultrastructure , Actin Cytoskeleton/ultrastructure , Adolescent , Adult , Aged , Endoplasmic Reticulum/ultrastructure , Female , Humans , Intercellular Junctions/ultrastructure , Intermediate Filaments/ultrastructure , Male , Microscopy, Electron , Microscopy, Electron, Scanning , Microtubules/ultrastructure , Microvilli/ultrastructure , Middle Aged , Synovial Membrane/pathologyABSTRACT
The effect of internal stabilization of a fracture of the femur on arterial blood oxygen levels, limb flow and oxygen consumption was measured in 24 dogs. Those with stabilized fractures bore weight on their limbs and were much more active. Without fracture stabilization the arterial oxygen tension fell by 10 per cent. With internal fixation this hypoxia did not develop. In fact, there was a 10 per cent increase beginning in the third week. Stabilization of the fracture gave a persistent increase in limb blood flow, but without stabilization this increase was transient and followed by a significant decrease. Over the 7-week observation period, the total oxygen consumption of the uninjured limbs in the stabilized group was twice that in the unstabilized group, an indication of their functional activity. Also with stabilization, the oxygen consumption of the uninjured limb was not significantly different from the opposite limb, whereas without stabilization the consumption was 32 per cent greater, an indication of the energy cost of countering instability.
