Spindle-shaped macrophages

Biopsy specimens from 17 mandibular fracture sites treated by open reduction with titanium in 12 patients showed doublelayered connective tissue, which consisted of dense fibrous connective tissue and relatively loose connective tissue containing proliferated blood vessels with hypertrophied endothelial cells [78 ]. The vascular endothelial cells expressed HLA-DR, CD54, and CD62P antigens in some cases they were CD62E-positive. CD68-positive, and CDllc-positive round or spindle-shaped macrophages had infiltrated around the small vessels and contained fine cytoplasmic titanium particles. In some cases CD4- - and CD8-y T lymphocytes had infiltrated around venules. 

Slender spindle-shaped fibroblasts are the commonest cell to be found in connective tissue. These cells, which manufacture matrix collagen and proteoglycans, have an elliptical nucleus and a cytoplasm which is contains extensive rough endoplasmic reticulum and Golgi apparatus, which are typical features of secretory cells. Mast cells are found widely within connective tissues and like fibroblasts these are secretory cells and characterized by a very granular cytoplasm. Almost as numerous as the fibroblasts and cytologically very similar to them, are macrophages, also called histiocytes or littoral cells. 

The cultures must be homogeneous (i.e., only macrophages) and cells must be more or less spindle shaped. The presence of cells with heterogenous shapes indicates that the original bone marrow isolate contained too many already mature macrophages that produced M-CSE or other such molecules involved in differentiation of precursor cells into dendritic cells, granulocytes, and so on. If cells look... 

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