Endogenous peroxidase in mast cells localized with a semipermeable membrane technique

Mast cells in meningiomas and brain inflammation

Background

Research focus in neuro-oncology has shifted in the last decades towards the exploration of tumor infiltration by a variety of immune cells and their products. T cells, macrophages, B cells, and mast cells (MCs) have been identified.

Methods

A systematic review of the literature was conducted by searching PubMed, EMBASE, Google Scholar, and Turning Research into Practice (TRIP) for the presence of MCs in meningiomas using the terms meningioma, inflammation and mast cells.

Results

MCs have been detected in various tumors of the central nervous system (CNS), such as gliomas, including glioblastoma multiforme, hemangioblastomas, and meningiomas as well as metastatic brain tumors. MCs were present in as many as 90 % of all high-grade meningiomas mainly found in the perivascular areas of the tumor. A correlation between peritumoral edema and MCs was found.

Interpretation

Accumulation of MCs in meningiomas could contribute to the aggressiveness of tumors and to brain inflammation that may be involved in the pathogenesis of additional disorders.

Biological implications of preformed mast cell mediators

Mast cells store an impressive array of preformed compounds (mediators) in their secretory granules. When mast cells degranulate, these are released and have a profound impact on any condition in which mast cell degranulation occurs. The preformed mast cell mediators include well-known substances such as histamine, proteoglycans, proteases, and preformed cytokines, as well as several recently identified compounds. Mast cells have recently been implicated in a large number of novel pathological settings in addition to their well-established contribution to allergic reactions, and there is consequently a large current interest in the molecular mechanisms by which mast cells act in the context of a given condition. In many cases, preformed mast cell mediators have been shown to account for functions ascribed to mast cells, and these compounds are hence emerging as major players in numerous pathologies. In this review we summarize the current knowledge of preformed mast cell mediators.

Semipermeable membrane techniques in quantitative enzyme histochemistry

Non-structurally bound, partially structurally bound or weakly structurally bound enzymes diffuse out of sections during the histochemical incubation period. Fixation of sections does not help to prevent diffusion since the enzymes may be inactivated by their chemical reaction with the fixative. Moreover watery fixatives cause partial leakage of enzymes into the fixative solution. The inclusion of macromolecular substances in the incubation media only partially prevents the leakage of enzymes. In the technique discussed here a semipermeable membrane is interposed between the incubating solution and the tissue section. Because only molecules with a molecular weight of 20 000 can penetrate the membranes, diffusion of enzymes is prevented, whereas substrate molecules and other components necessary for the staining reaction diffuse through the membrane. This technique is suitable for the histochemical demonstration of activity of oxidoreductases, transferases, hydrolases and isomerases. Particular attention is paid to how far semipermeable membrane methods are suitable for quantitative histochemical studies of enzymes.

Histochemical features of ragged-red fibres in diseased skeletal muscles

In the present communication, the activity of 24 oxidoreductases, transferases, isomerases and hydrolases was examined histochemically in ragged-red fibres of human skeletal muscle specimens. The biopsy material was obtained from patients with neuromuscular diseases caused by an abnormally metabolic functioning of the muscle mitochondria. The granular accumulations of the ragged-red fibres were characterized by an impressive activity of all mitochondrial and most non-mitochondrial enzymes examined, whether participating in the aerobic or in the anaerobic pathways. With the exception of mitochondrial Mg2(+)-stimulated ATPase, acid phosphatase and AMP-aminohydrolase, there was no activity of the other hydrolytic enzymes studied in these regions. The strong activity of mitochondrial ATPase points to the presence of loosely coupled and/or uncoupled mitochondria. Ragged-red fibres that exhibited a diffuse and corpuscular activity of acid phosphatase, were always undergoing necrotic changes. Adsorption studies with diluted enzyme solutions demonstrated that the granular accumulations display a specific, moderate affinity for glycolytic enzymes.

Histochemical features of tubular aggregates in diseased human skeletal muscle fibres

This communication presents the results obtained in tubular aggregates of 24 enzyme histochemical techniques for demonstrating activity of oxidoreductases, transferases, hydrolases and isomerases. The activity characteristics of the tubular aggregates in m. gluteus medius of 18 patients with diseases of the neuromuscular system were almost identical. A high activity of the mitochondrial enzymes, NADPH: tetrazolium oxidoreductase, NADH:tetrazolium oxidoreductase and cytochrome c oxidase, could be shown in the pathological structures, whereas the activity of the mitochondrial enzymes, glycerol-3-phosphate:menadione oxidoreductase, succinate:PMS oxidoreductase, malate:NAD+ oxidoreductase and isocitrate:NAD+ oxidoreductase, and the partial mitochondrial enzymes, malate:NADP+ oxidoreductase and isocitrate:NADP+ oxidoreductase, was very slight or even absent. There was a moderate to strong activity of the glycolytic enzymes lactate:NAD+ oxidoreductase, glyceraldehyde-3-phosphate:NAD+ oxidoreductase, phosphofructokinase, phosphoglucomutase and glucose phosphate isomerase. In contrast, the activity of alpha-glucan phosphorylase was slight. The activity of phosphogluconate:NADP+ oxidoreductase, glucose-6-phosphate:NADP+ oxidoreductase and 5'-nucleotidase was slight, whereas there was no activity of myosin ATPase and mitochondrial ATPase, acid phosphatase or alkaline phosphatase. The high activity of AMP-deaminase was very striking. The activity of peroxidase was moderate. Results obtained with adsorption studies point to adsorption of some of the enzymes studied to the tubular aggregates in vivo and this phenomenon very probably determined the histochemical characteristics of these structures.

Tissue mast cells in health and disease

Mast cells (MC) are regular constituents of soft tissue and occur with varying frequency in nearly every organ. They derive from monocytic cells occurring in the adhering mononuclear fraction of the peripheral blood. Their subsequent evolution into mature MCs is primed by a MC generating lymphokine released by sensitized T-cells on restimulation by the antigen. MC granules contain preformed heparin histamine and eosinophil chemotactic factors. Other factors such as leukotriene B4 can be produced by MCs following stimulation. This is the case during the initial phase of nonspecific inflammations, when MCs are stimulated by complement activation. In the immediate type hypersensitivity reaction giving rise to IgE, MC degranulation occurs independent from complement. In IgG and IgM mediated reactions, however, MC involvement is effected by complement consumption and C5 a generation. In delayed type hypersensitivity MCs increase locally. Their functional significance remains obscure. MC neoplasias are rare and generally confined to the dermis. Cutaneous mastocytoses are called benign mastocytoma when localized and urticaria pigmentosa when disseminated. Generalized mastocytosis involves extracutaneous tissue irrespective of skin involvement. Those associated with urticaria pigmentosa-like skin lesions, present at the onset of the disease, have a significantly higher survival rate than those lacking a primary skin involvement. The term urticaria pigmentosa should be reserved for cases of cutaneous mastocytosis without extracutaneous involvement. Cases of mastocytoses lacking primary skin lesions assume a malignant course and are additionally aggravated by high incidence of myeloproliferative disorders and MC leukemia. MC sarcoma is an extremely rare neoplasia of MCs which may also terminate as a MC leukemia.

Analysis of mast cells in rheumatoid arthritis and osteoarthritis by an avidin-peroxidase staining

As demonstrated by labeling with peroxidase, avidin was found to bind selectively and distinctly to mast cell granules. Inhibition studies suggested that avidin is bound by heparin. Based on this new mast cell staining procedure, mast cell distribution in the inflamed synovium of rheumatoid arthritis (RA) and osteoarthritis (OA) has been investigated. In the subsynovial layer, a significant decrease in mast cell numbers was observed in RA-synovium when compared with OA-synovium. This decrease correlated with the presence of lining cell ulcers and granulation tissue and can be interpreted as the result of mast cell degranuation induced by complement-mediated or immune complex-triggered mechanisms.

Immunocytochemical study of the glial fibrillary acidic protein in human neoplasms of the central nervous system

The distribution of the glial fibrillary acidic protein (GFAP) was investigated in sections of 131 paraffin-embedded brain neoplasms obtained at surgery or at autopsy. The unlabeled antibody immunoperoxidase (peroxidase-antiperoxidase, PAP) method was used. Equally good results were obtained from 17-year-old material and from recent material derived at surgery or autopsy and fixed with Bouin fluid or phosphate-buffered formalin. The perikaryons and processes of reactive astrocytes showed the most intense stain for GFAP. Positive reaction to antibody against GFAP of varying intensity was demonstrated in astrocytomas of various grades of malignancy (32 of 32), glioblastoma multiforme (10 of 10), subependymal giant cell astrocytoma (1 of 1), ependymoma (2 of 10), subependymoma (4 of 4), and astrocytes in mixed neoplasms (8 of 8). In two neoplasms diagnosed as malignant astrocytomas and in four neoplasms diagnosed as glioblastoma multiforme, GFAP stain was limited to a few neoplastic cells. Usually the stain was more intense over processes than in perikaryons, with the exception of gemistocytic astrocytomas and the giant cells in glioblastoma multiforme, which showed an equally intense stain over perikaryons and processes. The periphery of Rosenthal fibers was intensely positive for GFAP. In astrocytic neoplasms the number of GFAP-positive cells and the intensity of the stain were inversely proportional to the degree of malignancy. In the following neoplasms the reaction for GFAP was negative: oligodendroglioma (3), oligodendroblastoma (1), medulloblastoma (3), medulloepithelioma (1), neuroblastoma (1), pineocytoma (1), typical teratoma of the pineal (1), fibrosarcoma (1), pituitary adenoma (2), craniopharyngioma (1), chordoma (1), chemodectoma of globus jugulare (1), metastatic carcinoma (17), and lymphoma (8). In one of 18 meningiomas, endogenous peroxidase activity was seen in mast cells. All meningiomas studied were negative for GFAP. In one of six neurinomas a positive reaction for GFAP was detected over processes. The authors concluded that the immunostain for GFAP is useful in the diagnoses of astrocytic neoplasms and of mixed gliomas.

In vitro differentiation of rat peritoneal macrophages into mast cells: an enzymecytochemical study

Under special culture conditions, rat peritoneal mononuclear phagocytes have previously been shown to transform into typical mast cells, based on their histamine contents, the increase of their membrane IgE-receptors, and the development of metachromatic, electron-dense cytoplasmic granules. In the present investigation, the enzyme-cytochemical characteristics of these cells were examined prior to and during culture. The peritoneal macrophages were found to have strong paranuclear activity of nonspecific esterases and acid hydrolases, while they were negative for peroxidase and chloroacetate esterase. During culture, two main changes in enzyme activity were observed within all the cells: (1) Paranuclear activity was lost in favour of granular enzyme activity throughout the cytoplasm, and (2) chloroacetate esterase appeared in cultured cells and developed a strong granular activity. These findings are consistent with the macrophage nature of the seeded cells and their development into mast cells during culture. They give support to the theory that mast cells originate from the monocyte-macrophage lineage.

The use of the peroxidase reaction to obliterate staining of eosinophils by fluorescein-labelled conjugates

The staining of eosinophils by fluorescein conjugates can be obliterated by utilising the peroxidase activity of the eosinophil. The brown reaction product of 3,4,3',4'-tetraaminobiphenyl hydrochloride (DAB) with hydrogen peroxide was more effective than Lendrum's stain. A satisfactory alternative to the possibly carcinogenic DAB was 2,7-fluorenediamine.