Tissue fibroblasts

The various cell types are distributed differently within various types of connective tissue fibroblasts often found lying close to collagen fibres, whilst macrophages and mast cells usually appear in clusters around blood vessels. Additionally, whereas fibroblasts are widespread, macrophages are absent from some types of connective tissue, tendons for example. Specialized cells also occur within particular locations for example osteoblasts and osteoclasts (bone), chondrocytes (cartilage), adipocytes (fat tissue) and haemopoietic cells (bone marrow). 

Some changes were observed in the dermis. This was expressed by a changed cellular constitution of the connective tissue. Fibroblasts were predominant in the thin section of cellular elements. 

A layer-by-layer microfluidics technology was used to construct a 3D microscale hierarchical tissue-like structure. For instance, three layers of tissues, fibroblasts (human lung), myocytes (smooth muscle cells), and endothelial cells (human umbilical vein) were cultured on top of each other using consecutive microchannel cell matrix delivery. Cell viability was confirmed by fluorescent staining [862]. 

Classification Human interferons have been classified into three type s, a, p, and y, on the basis of their antigenicity. The a interferons are primarily leukocytic, whereas the p and y interferons are produced by connective tissue fibroblasts and T lymphocytes, respectively. Recombinant DNA techniques in bacteria have made available large quantities of a interferon/species A—designated a2(A) interferon—which has the advantage of being purer than previous preparations derived from leukocytes. Currently the other interferons have also been obtained by recombinant techniques. 

Approximately 30% of liver cells are nonparenchymal cells. Cell types located in the interlobular portal tracts include bile duct epithelial cells and connective tissue fibroblasts. Those located within the lobule interior are the rare fixed, natural killer lymphocytes (pit cells) and the more abundant endothelial cells lining the sinusoids, Kupffer cells, and stellate cells (also known as fat-storing or Ito cells). The recent... 

TNF is produced mainly by macrophages, but also by cells including lymphoid, mast and endothelial cells, cardiac myocytes, adipose tissue, fibroblasts and neuronal tissue. It has a number of actions on various organ systems, generally together with IL-1 and IL-6, including ... 

Malignant tumour derived from connective tissue fibroblast. Affecting the follicles. 

Fig. 10.1 Osteoclasts tunneling. Osteoclasts differentiate at cracks in the bone and form a tunnel (lacuna) containing a central capillary surrounded by connective tissue. Fibroblast-like precursors of osteoblasts are activated to become osteoblasts and new bone is formed (Modified from Fig. 22.54 in The Molecular Biology of the Cell. B. Alberts et al., 4th Ed. 2002. Garland Science, Taylor Francis Group, New York)...

Patterns of mesenchymal differentiation in cutaneous neoplasms are no less diverse than those encountered in deeper soft tissues. Fibroblastic or myofibroblastic, fibrohistiocytic, muscular, neural, epithelial, and vascular lesions may be seen as primary tumors in the dermis and subcutis. As is also true in deep soft tissues, the histologic evaluation of those neoplasms may fail to provide an unequivocal diagnosis. Hence immunophenotyping has proven to be valuable in this context. The diagnostic separation of various spindle-cell, polygonal-cell, epithelioid-cell, and small-cell lesions of the skin is assisted in many settings by immunohistochemical analysis. 

Often connective tissue fibroblasts divide in culture more rapidly than other cells in a tissue, eventually becoming the... 

Imai Y, Ibaraki K, Odajima R, Shishiba Y. Analysis of proteoglycan synthesis by retro-ocular tissue fibroblasts under the influence of interleukin 1 beta and transforming growth factor-beta. Eur J Endocrinol 1994 131 630-638. 

Imai Y, Odajima R, Inoue Y, Shishiba Y. Effect of growth factors on hyaluronan and proteoglycan synthesis by retroocular tissue fibroblasts of Graves ophthalmopathy in culture. Acta Endocrinol (Copenh) 1992 126 541-552. 

Other studies have investigated the production of chemokines by cells from the synovial membrane. RA synovial mononuclear leukocytes and fibroblasts produce and release various chemokines, either constitutively or following cytokine stimulation. Immunohistochemistry and in situ hybridization (39,42,43) showed that synovial macrophages are the dominant cell-type and produce IL-8 and MCP-1 constitutively. In contrast, synovial tissue fibroblasts release only small amounts of constitutive IL-8 and no MCP-1. However, these cells can be induced to produce IL-8 and MCP-1 after stimulation with IL-ip, TNF-a, or LPS (lipopolysaccharide) (39,42,44). Immunohistology showed that ENA-78 is predominantly localized in the synovial lining cells and is produced by macrophages and fibroblasts (37). Similarly, Gro-a was found to be expressed... 

L929 Mouse connective tissue Fibroblastic General studies... 

Dermal tissue Interacts with connective tissues, fibroblasts, macrophages, growth factors, and cytokines permeates blood vessels and granulation tissue... 

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