Macrophages found in the TISSUES, as opposed to those found in the blood (MONOCYTES) or serous cavities (SEROUS MEMBRANE).

Granular leukocytes with a nucleus that usually has two lobes connected by a slender thread of chromatin, and cytoplasm containing coarse, round granules that are uniform in size and stainable by eosin.

A congenital disease caused by an inborn error involving APOLIPOPROTEINS E leading to abnormal LIPID METABOLISM and the accumulation of GLYCOSPHINGOLIPIDS, particularly SPHINGOMYELINS in the HISTIOCYTES. This disorder is characterized by SPLENOMEGALY and the sea-blue histiocytes in the spleen and bone marrow after May Grunwald staining.

General term for the abnormal appearance of histiocytes in the blood. Based on the pathological features of the cells involved rather than on clinical findings, the histiocytic diseases are subdivided into three groups: HISTIOCYTOSIS, LANGERHANS CELL; HISTIOCYTOSIS, NON-LANGERHANS-CELL; and HISTIOCYTIC DISORDERS, MALIGNANT.

A 66-kDa peroxidase found in EOSINOPHIL granules. Eosinophil peroxidase is a cationic protein with a pI of 10.8 and is comprised of a heavy chain subunit and a light chain subunit. It possesses cytotoxic activity towards BACTERIA and other organisms, which is attributed to its peroxidase activity.

Proteins found in EOSINOPHIL granules. They are primarily basic proteins that play a role in host defense and the proinflammatory actions of activated eosinophils.

Group of disorders which feature accumulations of active HISTIOCYTES and LYMPHOCYTES, but where the histiocytes are not LANGERHANS CELLS. The group includes HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS; SINUS HISTIOCYTOSIS; xanthogranuloma; reticulohistiocytoma; JUVENILE XANTHOGRANULOMA; xanthoma disseminatum; as well as the lipid storage diseases (SEA-BLUE HISTIOCYTE SYNDROME; and NIEMANN-PICK DISEASES).

Benign, non-Langerhans-cell, histiocytic proliferative disorder that primarily affects the lymph nodes. It is often referred to as sinus histiocytosis with massive lymphadenopathy.

Malignant neoplasms composed of MACROPHAGES or DENDRITIC CELLS. Most histiocytic sarcomas present as localized tumor masses without a leukemic phase. Though the biological behavior of these neoplasms resemble lymphomas, their cell lineage is histiocytic not lymphoid.

A group of disorders resulting from the abnormal proliferation of and tissue infiltration by LANGERHANS CELLS which can be detected by their characteristic Birbeck granules (X bodies), or by monoclonal antibody staining for their surface CD1 ANTIGENS. Langerhans-cell granulomatosis can involve a single organ, or can be a systemic disorder.

Distinctive neoplastic disorders of histiocytes. Included are malignant neoplasms of MACROPHAGES and DENDRITIC CELLS.

Cytotaxins liberated from normal or invading cells that specifically attract eosinophils; they may be complement fragments, lymphokines, neutrophil products, histamine or other; the best known is the tetrapeptide ECF-A, released mainly by mast cells.

A rare form of non-Langerhans-cell histiocytosis (HISTIOCYTOSIS, NON-LANGERHANS-CELL) with onset in middle age. The systemic disease is characterized by infiltration of lipid-laden macrophages, multinucleated giant cells, an inflammatory infiltrate of lymphocytes and histiocytes in the bone marrow, and a generalized sclerosis of the long bones.

Diseases of LYMPH; LYMPH NODES; or LYMPHATIC VESSELS.

Abnormal increase of EOSINOPHILS in the blood, tissues or organs.

A cytokine that promotes differentiation and activation of EOSINOPHILS. It also triggers activated B-LYMPHOCYTES to differentiate into IMMUNOGLOBULIN-secreting cells.

One of several basic proteins released from EOSINOPHIL cytoplasmic granules. Eosinophil cationic protein is a 21-kDa cytotoxic peptide with a pI of 10.9. Although eosinophil cationic protein is considered a member of the RNAse A superfamily of proteins, it has only limited RNAse activity.

A slow-growing benign pseudotumor in which plasma cells greatly outnumber the inflammatory cells.

A CC-type chemokine that is specific for CCR3 RECEPTORS. It is a potent chemoattractant for EOSINOPHILS.

One of several basic proteins released from EOSINOPHIL cytoplasmic granules. Eosinophil major basic protein is a 14-kDa cytotoxic peptide with a pI of 10.9. In addition to its direct cytotoxic effects, it stimulates the release of variety of INFLAMMATION MEDIATORS.

A benign tumor composed, wholly or in part, of cells with the morphologic characteristics of HISTIOCYTES and with various fibroblastic components. Fibrous histiocytomas can occur anywhere in the body. When they occur in the skin, they are called dermatofibromas or sclerosing hemangiomas. (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 5th ed, p1747)

A relatively small nodular inflammatory lesion containing grouped mononuclear phagocytes, caused by infectious and noninfectious agents.

A 19-kDa cationic peptide found in EOSINOPHIL granules. Eosinophil-derived neurotoxin is a RIBONUCLEASE and may play a role as an endogenous antiviral agent.

They are oval or bean shaped bodies (1 - 30 mm in diameter) located along the lymphatic system.

General term for inflammation of adipose tissue, usually of the skin, characterized by reddened subcutaneous nodules.

Characteristic cells of granulomatous hypersensitivity. They appear as large, flattened cells with increased endoplasmic reticulum. They are believed to be activated macrophages that have differentiated as a result of prolonged antigenic stimulation. Further differentiation or fusion of epithelioid cells is thought to produce multinucleated giant cells (GIANT CELLS).

A group of related disorders characterized by LYMPHOCYTOSIS; HISTIOCYTOSIS; and hemophagocytosis. The two major forms are familial and reactive.

The formation of soft patches on the mucous membrane of a hollow organ, such as the urogenital tract or digestive tract.

A condition marked by the development of widespread xanthomas, yellow tumor-like structures filled with lipid deposits. Xanthomas can be found in a variety of tissues including the SKIN; TENDONS; joints of KNEES and ELBOWS. Xanthomatosis is associated with disturbance of LIPID METABOLISM and formation of FOAM CELLS.

A non-tuberculous mycobacterium causing cervical lymphadenitis in children. It very rarely causes pulmonary disease, and is believed to be non-pathogenic in animals.

Inflammation of the lymph nodes.

Development of lesions in the lymph node characterized by infiltration of the cortex or paracortex by large collections of proliferating histiocytes and complete or, more often, incomplete necrosis of lymphoid tissue.

Removal and pathologic examination of specimens in the form of small pieces of tissue from the living body.

Immunologic techniques based on the use of: (1) enzyme-antibody conjugates; (2) enzyme-antigen conjugates; (3) antienzyme antibody followed by its homologous enzyme; or (4) enzyme-antienzyme complexes. These are used histologically for visualizing or labeling tissue specimens.

Histochemical localization of immunoreactive substances using labeled antibodies as reagents.

A malignant disease characterized by progressive enlargement of the lymph nodes, spleen, and general lymphoid tissue. In the classical variant, giant usually multinucleate Hodgkin's and REED-STERNBERG CELLS are present; in the nodular lymphocyte predominant variant, lymphocytic and histiocytic cells are seen.

Enzymes that catalyze the hydrolysis of ester bonds within RNA. EC 3.1.-.

Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.

CCR receptors with specificity for CHEMOKINE CCL11 and a variety of other CC CHEMOKINES. They are expressed at high levels in T-LYMPHOCYTES; EOSINOPHILS; BASOPHILS; and MAST CELLS.

A condition characterized by infiltration of the lung with EOSINOPHILS due to inflammation or other disease processes. Major eosinophilic lung diseases are the eosinophilic pneumonias caused by infections, allergens, or toxic agents.

A general term for various neoplastic diseases of the lymphoid tissue.

A CC-type chemokine with specificity for CCR3 RECEPTORS. It is a chemoattractant for EOSINOPHILS.

Group of chemokines with adjacent cysteines that are chemoattractants for lymphocytes, monocytes, eosinophils, basophils but not neutrophils.

A form of bronchial disorder with three distinct components: airway hyper-responsiveness (RESPIRATORY HYPERSENSITIVITY), airway INFLAMMATION, and intermittent AIRWAY OBSTRUCTION. It is characterized by spasmodic contraction of airway smooth muscle, WHEEZING, and dyspnea (DYSPNEA, PAROXYSMAL).

Mononuclear cells with pronounced phagocytic ability that are distributed extensively in lymphoid and other organs. It includes MACROPHAGES and their precursors; PHAGOCYTES; KUPFFER CELLS; HISTIOCYTES; DENDRITIC CELLS; LANGERHANS CELLS; and MICROGLIA. The term mononuclear phagocyte system has replaced the former reticuloendothelial system, which also included less active phagocytic cells such as fibroblasts and endothelial cells. (From Illustrated Dictionary of Immunology, 2d ed.)

'Skin diseases' is a broad term for various conditions affecting the skin, including inflammatory disorders, infections, benign and malignant tumors, congenital abnormalities, and degenerative diseases, which can cause symptoms such as rashes, discoloration, eruptions, lesions, itching, or pain.

Subcutaneous nodules seen in 20-30% of rheumatoid arthritis patients. They may arise anywhere on the body, but are most frequently found over the bony prominences. The nodules are characterized histologically by dense areas of fibrinoid necrosis with basophilic streaks and granules, surrounded by a palisade of cells, mainly fibroblasts and histiocytes.

The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.

The number of WHITE BLOOD CELLS per unit volume in venous BLOOD. A differential leukocyte count measures the relative numbers of the different types of white cells.

The marking of biological material with a dye or other reagent for the purpose of identifying and quantitating components of tissues, cells or their extracts.