Histiocyte

Using monoclonal antibody techniques, in the bronchiolar submucosa M24U/T6 dendritic cells were the predominant population (75 % of the labelled cells), whereas M24r/T6 Langerhans cells represented less than 10 % of the labelled cells (So- 

In the rabbit, Schwarz (1963) described histiocytes commonly rounded with long projections. Tlieir relatively ample cytoplasm shows a well developed Golgi apparatus, and various numbers of electron-dense inclusions. Nuclear chromatin is aggregated to irregular clumped granules, while electron-lucent cords traverse the nucleus. 

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Hodgkin s disease, lymphocytic lymphoma, histiocytic lymphoma, mycosis fungoides, testicular cancer, Kaposi s sarcoma, breast cancer Acute leukemia, combination therapy for various cancers... 

The pathophysiology of HL is defined by the presence of the RS cell in a grouping of lymph nodes. The RS cell is a large cell morphologically with a multinucleated structure with pronounced eosinophilic nucleoli.5 In the affected lymph nodes, the RS cells are contained in a reactive milieu of T lymphocytes, eosinophils, histiocytes, and plasma cells, which makes them difficult to distinguish from these background cells. The natural course of the disease, if left untreated, is less than a 5% probability of surviving 5 years. 

Xanthoma Firm, raised nodules composed of lipid-containing histiocytes. 

Macrophage (peritoneal, pleural, alveolar spaces) Histiocytes (tissues) Monocytes (blood) some cell-mediated responses)... 

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. 

Subsequent to lysis of older erythrocytes in the spleen, heme released from hemoglobin is converted to bilirubin in the histiocytes. This sequence is shown in Figure 1-17-6. 

Heme metabolized in histiocytes Production of biliverdin releases carbon monoxide (CO)... 

Iron (Fe " ) released from hemoglobin in the histiocytes is bound to ferritin and then transported in the blood by transferrin, which can deliver it to tissues for synthesis of heme. Important proteins in this context are ... 

Histiocytic tumors Lysozyme, a-1-antitrypsin, a-l-antichymotrypsin, MAC-387, CD68... 

Malignant fibrous histiocytomas (MFH), often a wastebasket diagnosis in histology, cannot be established by immunohistochemistry. The expression of the histiocyte markers and FXIIIa (originally described as a fibrohisfiocytic marker that is also on dermal dendrocytes) (58) listed in Table 12 in the malignant cells of MFH remains controversial. In addition, these markers are also found in other sarcomas. 

Reid, M. B., Gray, C., Fear, J. D., and Bird, C. C. (1986) Immunohistological demonstration of factors Xllla and XIIIs in reactive and neoplastic fibroblastic and fibro-histiocytic lesions. Histopathol. 10,1171-1178. 

The dermis contains several types of cells, including fibroblasts, fat cells, macrophages, histiocytes, mast cells, and cells associated with the blood vessels and nerves of the skin. The predominant cell is the fibroblast, which is associated with biosynthesis of the fibrous proteins and ground substances such as hyaluronic acid, chondroitin sulfates, and mucopolysaccharides. 

Overexpression of PKC in U937 histiocytic lymphoma cells increased expression of PKCa and p isoforms. In response to TPA, parental U937 cells displayed growth arrest and differentiated into a monocyte/macrophage-like cell line, while PKC overexpressing cells underwent death. The abUity of GF109203X to inhibit TPA-induced cell death suggested that activation of a conventional isoform was necessary to induce apoptosis (de Vente et al., 1995). Activation of PKC enhanced and down-modulation of PKC activity reduced apoptosis of neuronal cells (Mailhos et al., 1994). Ceramide, an activator of PKC is an inducer of apoptosis (Muller et al, 1995 Hannun, 1998, Obeid et al., 1993). 

Mayne GC, Murray AW (1998) Evidence that protein kinase Ce mediates phorbol ester inhibition of calphostin C- and tumor necrosis factor-a-induced apoptosis in U937 histiocytic lymphoma cells J Biol Chem 273 24115-24121 McBain JA, Pettit GR, Mueller GC (1990) Phorbol esters activate proteoglycan metabolism in human colon cancer cells en route to terminal differentiation. Cell Growth Differ 1 281-291... 

Seven months postinjection there was some reduction in neurodegeneration copper was distributed normally in liver in intestine, copper accumulated in histiocytes... 

Anaphylactic and serum sickness reactions to ALG and murine monoclonal antibodies have been observed and usually require cessation of therapy. Complexes of host antibodies with horse ALG may precipitate and localize in the glomeruli of the kidneys. Even more disturbing has been the development of histiocytic lymphomas in the buttock at the site of ALG injection. The incidence of lymphoma as well as other forms of cancer is increased in kidney transplant patients. It appears likely that part of the increased risk of cancer is related to the suppression of a normally potent defense system against oncogenic viruses or transformed cells. The preponderance of lymphoma in these cancer cases is thought to be related to the concurrence of chronic immune suppression with chronic low-level lymphocyte proliferation. 

Tetrafluoroethylene was tested for carcinogenicity in one study in mice and one study in rats by inhalation. In both sexes of mice, it increased the incidence of hepatocellular carcinomas, histiocytic sarcomas and haem angiosarcomas in the liver. In rats of both sexes, it increased the incidence of hepatocellular carcinomas and kidney tubule cell adenomas. 

A 54-year-old woman and a 62-year-old man with catheter blockages both developed aseptic peritonitis (166). In both cases clots had earlier been removed by laparoscopy, which also showed diffuse thickening around the tip and in the peritoneal fat, with fluid accumulation or inflammation and whitish urticarialike plaques. The tissue was granulomatous, with histiocytes, fibrosis, and pseudo-amyloid material that could not be labeled by anti-insulin antibodies. The peritoneal fluid contained a lot of fibrin, monocytes, lymphocytes, and macrophages, but no bacteria or cancer cells. 

Diffuse histiocytic lymphoma Cyclophosphamide, vincristine, methotrexate, and cytarabine (COMA). 

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