Comparison of histochemical staining techniques for detecting mast cells in oral lesions

ABSTRACT

Mast cells are large cells with granular cytoplasm that participate in wound healing, angiogenesis and defense against pathogens. They also contribute to inflammation by initiating innate and acquired immunity. The granules of these cells exhibit characteristic staining properties. We investigated toluidine blue, astra blue, Alcian blue-pyronin Y and May-Grunwald Giemsa stains for mast cells in various oral lesions and assessed the efficacy of each for identifying mast cells. Sections were obtained from 10 each of diagnosed cases of inflammatory fibrous hyperplasia, periapical cyst, mild dysplasia, oral submucous fibrosis and oral squamous cell carcinoma and stained using the stains listed above. Mast cells were assessed for their presence, contrast of the mast cell in the connective tissue background and number. We found that May-Grunwald Giemsa stain was the best for identification of mast cells, although toluidine blue staining is less time-consuming. Overall we obtained better results using May-Grunwald Giemsa and toluidine blue for staining mast cells.     

Staining Mast Cells for Morphometric Evaluation on an Image Analysis System

Multiple skin sections from three nonhuman primates (Macaca mulatta) and three hairless guinea pigs (Cavia porcellus) were stained with 12 different histologic stains to determine whether mast cells could be selectively stained for morphometric analysis using an image analysis system (IAS). Sections were first evaluated with routine light microscopy for mast cell granule staining and the intensity of background staining. Methylene blue-basic fuchsin and Unna's method for mast cells (polychrome methylene blue with differentiation in glycerin-ether) stained mast cell granules more intensely than background in both species. Toluidine blue-stained sections in the guinea pig yielded similar results. Staining of the nuclei of dermal connective tissue was enhanced with the methylene blue-basic fuchsin and toluidine blue stains. These two stains, along with the Unna's stain, were further evaluated on an IAS with and without various interference filters (400.5-700.5 nm wavelengths). In both the methylene blue-basic fuchsin and toluidine blue stained sections, mast cell granules and other cell nuclei were detected together by the IAS. The use of interference filters with these two stains did not distinguish mast cell granules from stained nuclei. Unna's stain was the best of the 12 stains evaluated because mast cell granule staining was strong and background staining was faint. This contrast was further enhanced by interference filters (500.5-539.5 nm) and allowed morphometric measurements of mast cells to be taken on the IAS without background interference.     

Staining properties of duodenal mast cells in 48/80-treated rats

Summary Mast cells in the tongue, mesentery and lamina propria of the duodenal mucosa in normal and 48/80-treated rats were observed at different time intervals. The tissues were studied comparatively after staining with toluidine blue, acridine orange or alcian bluesafranin. Under the experimental conditions used, the mast cells in the tongue and mesentery showed constant positive reactions to toluidine blue and acridine orange, both of which failed to demonstrate the presence of mast cells in the lamina propria of the duodenal mucosa. The combined alcian blue-safranin stain elicited a safranin-positive reaction in the mast cells of the tongue and mesentery and an alcian blue reaction in those of the lamina propria of the duodenal mucosa. This alcianophilia of the duodenal mast cells was not affected by compound 48/80. On the other hand, the safranin stain of the tongue and mesentery mast cells was altered to alcian blue by the drug. The results are discussed in the light of recent developments in mast cell research.This work was supported by grant MA-2236 of the Medical Research Council of Canada.     

Morphological, cytochemical and ultrastructural studies of a case of systemic mastocytosis

Morphological, cytochemical and ultrastructural studies of mast cells were carried out in a patient affected with systemic mastocytosis. Neoplastic mast cells showed morphological features between classic tissue mast cells and circulating basophils. They showed strong granule metachromasia after toluidine blue, faint positivity to Hotchkiss reaction, strong positivity to chloroacetate esterase, while they were negative to alkaline phosphatase. Ultrastructural observations showed heterogeneity of granules, most of which had homogenous fine dotted contents. The origin and linkage between mast cells and circulating basophils are discussed.     

Porcine Intestinal Mast Cells. Evaluation of Different Fixatives for Histochemical Staining Techniques Considering Tissue Shrinkage

Staining of mast cells (MCs), including porcine ones, is critically dependent upon the fixation and staining technique. In the pig, mucosal and submucosal MCs do not stain or stain only faintly after formalin fixation. Some fixation methods are particularly recommended for MC staining, for example the fixation with Carnoy or lead salts. Zinc salt fixation (ZSF) has been reported to work excellently for the preservation of fixation-sensitive antigens. The aim of this study was to establish a reliable histological method for counting of MCs in the porcine intestinum. For this purpose, different tissue fixation and staining methods that also allow potential subsequent immunohistochemical investigations were evaluated in the porcine mucosa, as well as submucosa of small and large intestine. Tissues were fixed in Carnoy, lead acetate, lead nitrate, Zamboni and ZSF and stained subsequently with either polychromatic methylene blue, alcian blue or toluidine blue. For the first time our study reveals that ZSF, a heavy metal fixative, preserves metachromatic staining of porcine MCs. Zamboni fixation was not suitable for histochemical visualization of MCs in the pig intestine. All other tested fixatives were suitable. Alcian blue and toluidine blue co-stained intestinal goblet cells which made a prima facie identification of MCs difficult. The polychromatic methylene blue proved to be the optimal staining. In order to compare MC counting results of the different fixation methods, tissue shrinkage was taken into account. As even the same fixation caused shrinkagedifferences between tissue from small and large intestine, different factors for each single fixation and intestinal localization had to be calculated. Tissue shrinkage varied between 19% and 57%, the highest tissue shrinkage was found after fixation with ZSF in the large intestine, the lowest one in the small intestine after lead acetate fixation. Our study emphasizes that MC counting results from data using different fixation techniques can only be compared if the respective studyimmanent shrinkage factor has been determined and quantification results are adjusted accordingly.Key words: mast cell, swine, fixation, tissue shrinkage factor     

常用实验动物不同组织部位肥大细胞异质性的组织学特点比较

目的探讨并比较六种常用实验动物不同部位肥大细胞异质性的形态学特点。方法应用麻醉后处死的方法,取小鼠、大鼠、豚鼠、兔、犬和猴的皮肤、肺脏、乙状结肠和脾脏组织,经4%中性缓冲甲醛溶液或Bouin’s液固定后,制作常规组织切片,分别作HE、甲苯胺蓝、阿尔新蓝-藏红和P物质免疫组织化学染色,镜下观察并应用彩色病理图像分析软件进行形态学分析;另取皮肤组织固定于磷酸缓冲戊二醛溶液,制作常规超薄切片,透射电镜下观察肥大细胞超微结构。结果六种动物不同组织中肥大细胞各有其分布特点,且在形态大小、异染性及染色特性等方面表现各异,肥大细胞密度和形态学参数差异有显著性（P〈0.05）;豚鼠、犬和猴皮肤肥大细胞颗粒具有特殊亚微结构;小鼠皮肤组织内可见P物质免疫阳性肥大细胞和神经纤维,犬脾脏内可见P物质免疫阳性肥大细胞。结论在六种实验动物的同一组织中以及同一种动物不同组织中,肥大细胞具有明显的异质性,此异质性对采用实验动物开展与肥大细胞功能相关的动物实验研究具有重要参考价值。     

A Neoplastic Connective Tissue Mast Cell Capable of Continuous Growth In Tissue Culture

A neoplastic connective tissue mast cell from a dog mast cell sarcoma has been grown in tissue culture for 50 passages over a period of 2 years. The cells were grown as monolayer cultures in glass bottles, using Eagle's basal medium fortified with calf serum. The cultures were contaminated with an Alkaligenes sp. for 10 months but finally were sterilized bacteriologically by treatment with specific antiserum combined with antibiotics. The cells grow in a fibroblastic pattern, and contain mitochondria, mast cell granules, and lipid granules or droplets. The mast cell granules stain basophilic with Giemsa's stain and metachromatically with azure A or toluidine blue. They also stain with Sudan black B and with periodic acid-Schiff stain. The interphase nuclei are vesicular, contain from 1 to 20 nucleoli, and frequently show bizarre outlines. Multinucleate cells are often seen, as are mitotic figures. Extracellular fibrous material occurs in all cultures and apparently originates from the cell surface. This material does not have the structure of connective tissue fibers and has not been identified. The cells develop an increased number of metachromatic granules when grown in medium containing heparin and an increased number of sudanophilic granules when grown in medium containing stearic acid. Only small amounts of histamine were present in the tumor from which this cell line was derived and in the cells grown in tissue culture.     

Some studies on the fluorescence of mast cells after paraformaldehyde treatment

Summary Air dried peritoneal fluid and tissue spreads from rat, mouse, hamster, rabbit, guinea pig, cat, chicken, and frog were treated with paraformaldehyde (pCHO) at 80 ° C for 1 hr. Only rat and mouse mast cells fluoresced. In the rat, mast cells fluoresced whether present in vascular or avascular areas of mesentery, in fat depots, or in peritoneal fluid. Photographs were obtained by fluorescence microscopy, the preparations were then stained and the same fields rephotographed in white light. Comparison of the photographs showed that every fluorescent rat mesentery mast cell also stained with acidified toluidine blue and with Astrablau; a few fluorescent cells did not stain with toluidine blue and an occasional cell that did not fluoresce stained with this dye or with Astrablau. Paraformaldehyde depressed somewhat toluidine blue, inhibited strongly Astrablau, and abolished Alcian blue binding. It had no effect on the staining of purified heparin in model experiments.Reserpine administration in the rat did not prevent visualization of mast cells by the pCHO method.These experiments indicate that all rat mast cells contain serotonin, regardless of cell size (age ?) or site and suggest that no massive, cyclic release of this amine occurs either physiologically or in response to reserpine treatment.Some of the experiments for this paper were carried out in the laboratory of Dr. G. Bloom, Department of Cell Research and Genetics, Karolinska Institutet, Stockholm, Sweden, (September and October, 1963). I wish to acknowledge the help and cooperation of the members of his staff, and especially Dr. Martin Ritzén, whose open, warm, efficient and enthusiastic manner enabled me to accomplish much in a relatively short time. Availability of darkroom facilities to pursue much of the work in the laboratories of Dr. W. Bargmann, Anatomisches Institut, Neue Universität, Kiel, Germany and of Dr. R. Robineaux, Hôpital St. Antoine, Paris, is also gratefully acknowledged. Grant support was furnished by the American Heart Association (62 G 118) and NSF (GB-4166) (to the author), by NIH 5 T 1 GM 102, and by the Swedish Medical Research Council (to Prof. B. Uvnäs and Dr. G. Bloom).This paper is dedicated to Dr. Berta Scharrer on the occasion of her 60th birthday.     

On the nature of the metachromatic cells of pancreatic islets

Summary Islet cells with cytoplasmic granules metachromatically stained by toluidine blue are found in the pancreas of dog, cat, pig, rabbit, teleostian fish, monkey and man, but not in the rat, mouse and guinea pig; dubious results are obtained on duck and ox islets. These cells do not react with the staining methods for the demonstration of A- and B-cells; conversely, they are silver-impregnated by a modification of Davenport's method, and, at least in dog islets, can be readily identified with dark-field microscopy and stained blue with the Mallory-Heidenhain trichrome stain. No obvious changes of this cell type are found either in synthalintreated dogs or in diabetic men.The Authors suggest that the islet argyrophil-metachromatic cells (A₁-cells of Swedish Authors) are identical with D-cells and very likely represent a morphologically and functionally indipendent cell type.     

间接免疫过氧化物酶技术鉴定猪和牛的肥大细胞

用小鼠抗人肥大细胞类胰蛋白酶单克隆抗体ＡＡ１,ＡＡ３及ＡＡ５的间接免疫过氧化物酶技术对经Ｃａｒｎｏｙ液或中性缓冲福尔马林固定的猪和犊牛空肠,舌及胸腺的石蜡切片进行了免疫染色。对猪和牛的肥大细胞特异性免疫染色与常规的组织化学染色的结果进行了比较。     

Mast Cells Produce a Unique Chondroitin Sulfate Epitope

The granules of mast cells contain a myriad of mediators that are stored and protected by the sulfated glycosaminoglycan (GAG) chains that decorate proteoglycans. Whereas heparin is the GAG predominantly associated with mast cells, mast cell proteoglycans are also decorated with heparan sulfate and chondroitin sulfate (CS). This study investigated a unique CS structure produced by mast cells that was detected with the antibody clone 2B6 in the absence of chondroitinase ABC digestion. Mast cells in rodent tissue sections were characterized using toluidine blue, Leder stain and the presence of mast cell tryptase. The novel CS epitope was identified in rodent tissue sections and localized to cells that were morphologically similar to cells chemically identified as mast cells. The rodent mast cell-like line RBL-2H3 was also shown to express the novel CS epitope. This epitope co-localized with multiple CS proteoglycans in both rodent tissue and RBL-2H3 cultured cells. These findings suggest that the novel CS epitope that decorates mast cell proteoglycans may play a role in the way these chains are structured in mast cells.     

Relationships between permeable vessels, nerves, and mast cells in rat cutaneous neurogenic inflammation

Electrical stimulation of rat sensory nerves produces cutaneous vasodilation and plasma protein extravasation, a phenomenon termed "neurogenic inflammation". Rat skin on the dorsum of the paw developed neurogenic inflammation after electrical stimulation of the saphenous nerve. In tissue sections, the extravasation of the supravital dye monastral blue B identified permeable vessels. Mast cells were identified by toluidine blue stain. Permeable vessels were significantly more dense in the superficial 120 microns of the dermis than in the deeper dermis, whereas mast cells were significantly more frequent in the deeper dermis. The relationships between nociceptive sensory nerve fibers, permeable vessels, and mast cells were examined by indirect immunohistochemistry for calcitonin gene-related peptide (CGRP), neurokinin A (NKA), and substance P (SP). CGRP-, NKA-, and SP-containing nerves densely innervated the superficial dermis and appeared to innervate the vessels that became permeable during neurogenic inflammation. In contrast, mast cells were not associated with either permeable vessels or nerve fibers. These data suggest that electrical stimulation of rat sensory nerves produces vascular permeability by inducing the release of neuropeptides that may directly stimulate the superficial vascular bed. Mast cells may not be involved in this stage of cutaneous neurogenic inflammation in rat skin.     

Reduction in rat mesentery mast cell staining after degranulation by protamine. A competitive antagonism.

Degranulation of rat mesentery mast cells by increasing concentrations of protamine causes a parallel decrease in the numbers of mast cells stained with toluidine blue or with berberine sulfate. No decrease in mast cell numbers occurs when degranulation is inhibited. Since protamine does not enter into non stimulated mast cells, these results suggest that this reduction in mast cell numbers is caused by the binding of protamine to the anionic sites of heparin of exocytosed granules thereby preventing their staining. There seems to be a competitive antagonism between protamine and toluidine blue at the anionic sites of heparin for increasing concentrations of toluidine blue progressively reverse the reduction in mast cell numbers.     

Mast cell "disappearance" in chronic murine graft-vs-host disease (GVHD)-ultrastructural demonstration of "phantom mast cells"

Mast cells were studied during the induction of chronic graft-vs-host disease (GVHD) induced in mice across minor histocompatibility barriers. B10.D2 spleen cells (or control BALB/c cells) were injected into irradiated (600 rad) BALB/c recipients. Serial skin biopsies were taken over 26 days, during which time changes occurred resembling scleroderma, namely, dermal fibrosis, a mononuclear cell infiltrate, and loss of fat and appendages. Mast cells, when stained with toluidine blue, "disappeared" from GVHD, but not from control skin. Ultrastructural analysis showed that mast cells in GVHD skin were indeed present but underwent degranulation. Some mast cells showed only pale expanded sacs, indicating granule depletion. Because these cells could not be seen by toluidine blue staining but were plainly present, we have called them "phantom mast cells." Cellular activation occurred in many GVHD mast cells as shown by increased cytoplasmic activity, with numerous Golgi complexes, ribosomes, granular endoplasmic reticulum, and small vesicles. No identifiable mast cells were seen after day 19. No significant changes were seen in the mast cells of syngeneic control mice. We believe that immunologic processes in chronic GVHD cause a slow release of mast cell granule contents, which is different from anaphylactic degranulation. The depleted mast cells (invisible by toluidine blue staining) are also activated, perhaps in an attempt to replete their stores of granule contents. We discuss the relation of mast cell changes to fibrosis.     

A Selective Stain for Mitotic Figures, Particularly in the Developing Brain

A selective stain for mitotic figures is valuable where autoradiographic counting is not required, especially in the developing brain. Most work in this field has been based on conventional nuclear stains which do not differentiate mitotic figures from resting cells by color. Hematoxylin, Feulgen, gallocyanin and Nissl methods have been used particularly. The method described uses a modified Bouin fixative, followed by hydrolysis in 1 N HCl. Mitotic figures are selectively stained using crystal violet, with nuclear fast red as the counterstain for resting cells. The method has been tested using material from postnatal and fetal sheep, guinea pig and rat. Using paraffin mounted serial sections it is applicable to all organs. The method was very successful on developing rat brain, particularly for detail and quantitative estimation in the early stages of prenatal development, which was of primary interest. Nucleated cells of the erythrocytic series, keratin and what appear to be mast cells were found to stain. When nuclear counting or cell recognition were required these did not cause any difficulty, except in prenatal liver. The highly selective method presented stains mitotic figures, in all tissue tested, an intense blue against a background of red resting cells.     

Enzyme histochemistry of tryptase in stomach mucosal mast cells of the mouse.

We investigated the histochemical characteristics of mast cell tryptase in different mouse tissues. By use of peptide substrates, tryptase activity could be demonstrated in unfixed connective tissue mast cells in different tissues, including the stomach. Tryptase activity was better localized after aldehyde fixation and frozen sectioning, and under such conditions was also demonstrated in mucosal mast cells of the stomach but not in those of the gut mucosa. Double staining by enzyme histochemistry followed by toluidine blue indicated that the tryptase activity was present only in mast cells and that all mast cells in the stomach mucosa contained the enzyme. The peptide substrates z-Ala-Ala-Lys-4-methoxy-2-naphthylamide and z-Gly-Pro-Arg-4-methoxy-2-naphthlyamide, which are substrates of choice for demonstrating tryptase in other species, were most effective for demonstrating mouse tryptase. The use of protease inhibitors further indicated that activity present in all mast cells was tryptase. Safranin O did not stain stomach mucosal mast cells, suggesting that the tryptase present in these cells was active in the absence of heparin sulfate proteoglycan.     

A selective stain for mitotic figures, particularly in the developing brain

A selective stain for mitotic figures is valuable where autoradiographic counting is not required, especially in the developing brain. Most work in this field has been based on conventional nuclear stains which do not differentiate mitotic figures from resting cells by color. Hematoxylin, Feulgen, gallocyanin and Nissl methods have been used particularly. The method described uses a modified Bouin fixative, followed by hydrolysis in 1 N HCl. Mitotic figures are selectively stained using crystal violet, with nuclear fast red as the counterstain for resting cells. The method has been tested using material from postnatal and fetal sheep, guinea pig and rat. Using paraffin mounted serial sections it is applicable to all organs. The method was very successful on developing rat brain, particularly for detail and quantitative estimation in the early stages of prenatal development, which was of primary interest. Nucleated cells of the erythrocytic series, keratin and what appear to be mast cells were found to stain. When nuclear counting or cell recognition were required these did not cause any difficulty, except in prenatal liver. The highly selective method presented stains mitotic figures, in all tissue tested, an intense blue against a background of red resting cells.     

Hepatic mast cells in rats infected with Taenia taeniaeformis

Mast cells appeared in the liver around metacestodes of Taenia taeniaeformis by 13 days after infection (DAI) of rats. The cells often occurred in clusters. The population increased until 28 DAI, then gradually declined. These hepatic mast cells (HMC) were compared to intestinal mucosal mast cells (MMC) and connective tissue mast cells (CTMC) histochemically, morphologically and in their response in vivo to Compound (built|48/80) and dexamethasone. Hepatic mast cells were similar to MMC in that they stained strongly blue with Astra blue at pH 1·0, could not be demonstrated with 0·005% toluidine blue, disappeared after treatment with dexamethasone, and were unaffected by 48/80. Immunoglobulin-containing cells in the liver were characterized by immunofluorescence. Immunoglobulin E-positive, and to a lesser extent IgG_2a-, and IgG_2c-positive cells surround the parasites in increasing numbers until 28 DAI, then declined. Many IgE-positive cells were HMC, and the IgE was frequently located intracytoplasmically. These cells were clearly distinguishable from eosinophils which stained characteristically with Giemsa and did not react with the anti-IgE probe. The results suggest that mast cell progenitors may be induced to localize and proliferate at the host-parasite interface in the Taenia-infected livers, giving rise to a cell population comparable to the MMC often seen at parasitized mucosal surfaces.     

Indole reactions of mast cells and enterochromaffin cells related to fixations with and without aldehydes

Summary Survey of a considerable number of rat, mouse and hog tissues which presented large numbers of mast cells in preparations stained with toluidine blue and other metachromatic or basic dyes at low pH levels, revealed numbers of oval bodies of about the same size as mast cells which reacted weakly or even moderately to the postcoupled benzylidene indole reaction. The numbers of these were always less than that of mast cells in toluidine blue sections of the same blocks. They never occurred in clusters of perhaps 15–20 in a single high power field, as mast cells often do. Smooth and especially striated muscle which often formed the background tissue where most mast cells are found with metachromatic stains, regularly present indole reactions due to protein tryptophan. This is usually equal to or stronger than that in the supposed mast cells.Indole reactive bodies whose morphology suggests mast cells are also present in similar numbers in formaldehyde and glutaraldehyde fixed tissue as well as with aldehyde free fixations. Glutaraldehyde and formaldehyde are known to inhibit the benzylidene reaction of 5-HT in vitro (30 min for glutaraldehyde, 3 h for formaldehyde) (Lillie, 1977). This action was avoided in mercury and lead heavy metal fixations and in acetone, Carnoy, chloroform methanol and similar fixations.The mast cell-like bodies are best explained as tangential or oblique sections of individual muscle fibers. We have described the same phenomenon with the ferric ferricyanide (Golodetz-Unna, 1909) reaction (Lillie et al., 1978a), and the PCB reaction is that of tryptophan in these muscle cell sections.In contrast to the DMAB type reaction failure acid diazosafranin successfully demonstrated mast cells with both aldehyde and aldehyde free fixations. This reaction has been shown to occur with 5-HT and 5-HTP (Lillie et al., 1973).     

牛蛙肥大细胞的组织化学与形态学

目的鉴定牛蛙组织中肥大细胞的存在。方法用于肥大细胞研究的一些常规组织化学技术与形态学方法。结果牛蛙的舌、肠、肠系膜和脾中肥大细胞数量较多,少量也见于神经、心、肾、肝和皮肤等多种组织中。肥大细胞有沿血管周和神经分布的倾向。脾脏中的肥大细胞形状比较一致,呈圆形或卵圆形,而在其它部位的肥大细胞则形态多样。Bouin氏液及Carnoy氏液是牛蛙肥大细胞优良的固定液。然而,与哺乳动物的黏膜肥大细胞相似的是,中性缓冲福尔马林(NBF)固定显著的阻断了牛蛙肠黏膜肥大细胞(MMC)的染色。有趣的是,甲苯胺蓝是牛蛙肥大细胞的最佳染料,它比阿尔新蓝能很好地显示牛蛙的肥大细胞。透射电镜下证实,牛蛙肥大细胞中含有大量特征性的胞浆颗粒。肥大细胞靠近雪旺氏细胞,并可见于神经束膜间,甚至以其突起与神经束膜相连。结论通过组织化学与形态学研究证实了牛蛙组织中肥大细胞的存在,再次证实肥大细胞与外周神经之间存在密切的解剖学关系。