ASSESSMENT OF MAST IN EUROPEAN PATIENT-CENTERED TELEMEDICINE PILOTS.

PubMed

Ekeland, Anne Granstrøm; Grøttland, Astrid

2015-01-01

Model for ASsessment of Telemedicine Applications (MAST) is a health technology assessment (HTA) inspired framework for assessing the effectiveness and contribution to quality of telemedicine applications based on rigorous, scientific data. This study reports from a study of how it was used and perceived in twenty-one pilots of the European project RENEWING HEALTH (RH). The objectives of RH were to implement large-scale, real-life test beds for the validation and subsequent evaluation of innovative patient-centered telemedicine services. The study is a contribution to the appraisal of HTA methods. A questionnaire was administered for project leaders of the pilots. It included questions about use and usefulness of MAST for (i) preceding considerations, (ii) evaluation of outcomes within seven domains, and (iii) considerations of transferability. Free text spaces allowed for proposals of improvement. The responses covered all pilots. A quantitative summary of use and a qualitative analysis of usefulness were performed. MAST was used and considered useful for pilot evaluations. Challenges included problems to scientifically determine alternative service options and outcome within the seven domains. Proposals for improvement included process studies and adding domains of technological usability, responsible innovation, health literacy, behavior change, caregiver perspectives and motivational issues of professionals. MAST was used according to its structure. Its usefulness in patient centered pilots can be improved by adding new stakeholder groups. Interdependencies between scientific rigor, resources and timeliness should be addressed. Operational options for improvements include process studies, literature reviews and sequential mini-HTAs for identification of areas for more elaborate investigations.

New developments in mast cell biology

PubMed Central

Kalesnikoff, Janet; Galli, Stephen J.

2010-01-01

Mast cells can function as effector and immunoregulatory cells in IgE-associated allergic disorders, as well as in certain innate and adaptive immune responses. This review will focus on exciting new developments in the field of mast cell biology published within the last year. It will highlight advances in the understanding of FcεRI-mediated signaling and mast cell activation events, as well as in the use of genetic models to study mast cell function in vivo. Finally, we will discuss newly identified roles of mast cells or individual mast cell products, such as proteases and IL-10, in host defense, cardiovascular disease and tumor biology, and in settings in which mast cells have anti-inflammatory or immunosuppressive functions. PMID:18936782

Mast Cells in Gastrointestinal Disease

PubMed Central

Ramsay, David B.; Stephen, Sindu; Borum, Marie; Voltaggio, Lysandra

2010-01-01

The function of mast cells in allergic inflammatory reactions is well documented in the literature. Mast cells also play an important role in the regulation of gastrointestinal visceral sensitivity and vascular permeability. Several studies have noted an increased number of mast cells in the mucosa of patients with gastrointestinal diseases such as irritable bowel syndrome, mastocytic enterocolitis, and systemic mastocytosis. The role of mast cells in the symptomatology of these and other diseases has only recently been fully appreciated and could provide avenues for new therapeutic opportunities. This paper examines studies that have evaluated the role of mast cells in various gastrointestinal diseases. PMID:21301631

Mast cells and mastocytosis

PubMed Central

2008-01-01

Mast cells have been recognized for well over 100 years. With time, human mast cells have been documented to originate from CD34+ cells, and have been implicated in host responses in both innate and acquired immunity. In clinical immunology, they are recognized for their central role in IgE-mediated degranulation and allergic inflammation by virtue of their expression of the high-affinity receptor for IgE and release of potent proinflammatory mediators. In hematology, the clinical disease of mastocytosis is characterized by a pathologic increase of mast cells in tissues, often associated with mutations in KIT, the receptor for stem cell factor. More recently, and with increased understanding of how human mast cells are activated through receptors including the high-affinity receptor for IgE and KIT, specific tyrosine kinase inhibitors have been identified with the potential to interrupt signaling pathways and thus limit the proliferation of mast cells as well as their activation through immunoglobulin receptors. PMID:18684881

Mast Cells: Key Contributors to Cardiac Fibrosis

PubMed Central

Widiapradja, Alexander

2018-01-01

Historically, increased numbers of mast cells have been associated with fibrosis in numerous cardiac pathologies, implicating mast cells in the development of cardiac fibrosis. Subsequently, several approaches have been utilised to demonstrate a causal role for mast cells in animal models of cardiac fibrosis including mast cell stabilising compounds, rodents deficient in mast cells, and inhibition of the actions of mast cell-specific proteases such as chymase and tryptase. Whilst most evidence supports a pro-fibrotic role for mast cells, there is evidence that in some settings these cells can oppose fibrosis. A major gap in our current understanding of cardiac mast cell function is identification of the stimuli that activate these cells causing them to promote a pro-fibrotic environment. This review will present the evidence linking mast cells to cardiac fibrosis, as well as discuss the major questions that remain in understanding how mast cells contribute to cardiac fibrosis. PMID:29329223

Mast cells express 11β-hydroxysteroid dehydrogenase type 1: a role in restraining mast cell degranulation.

PubMed

Coutinho, Agnes E; Brown, Jeremy K; Yang, Fu; Brownstein, David G; Gray, Mohini; Seckl, Jonathan R; Savill, John S; Chapman, Karen E

2013-01-01

Mast cells are key initiators of allergic, anaphylactic and inflammatory reactions, producing mediators that affect vascular permeability, angiogenesis and fibrosis. Glucocorticoid pharmacotherapy reduces mast cell number, maturation and activation but effects at physiological levels are unknown. Within cells, glucocorticoid concentration is modulated by the 11β-hydroxysteroid dehydrogenases (11β-HSDs). Here we show expression and activity of 11β-HSD1, but not 11β-HSD2, in mouse mast cells with 11β-HSD activity only in the keto-reductase direction, regenerating active glucocorticoids (cortisol, corticosterone) from inert substrates (cortisone, 11-dehydrocorticosterone). Mast cells from 11β-HSD1-deficient mice show ultrastructural evidence of increased activation, including piecemeal degranulation and have a reduced threshold for IgG immune complex-induced mast cell degranulation. Consistent with reduced intracellular glucocorticoid action in mast cells, levels of carboxypeptidase A3 mRNA, a glucocorticoid-inducible mast cell-specific transcript, are lower in peritoneal cells from 11β-HSD1-deficient than control mice. These findings suggest that 11β-HSD1-generated glucocorticoids may tonically restrain mast cell degranulation, potentially influencing allergic, anaphylactic and inflammatory responses.

Lipid Rafts in Mast Cell Biology

PubMed Central

Silveira e Souza, Adriana Maria Mariano; Mazucato, Vivian Marino; Jamur, Maria Célia; Oliver, Constance

2011-01-01

Mast cells have long been recognized to have a direct and critical role in allergic and inflammatory reactions. In allergic diseases, these cells exert both local and systemic responses, including allergic rhinitis and anaphylaxis. Mast cell mediators are also related to many chronic inflammatory conditions. Besides the roles in pathological conditions, the biological functions of mast cells include roles in innate immunity, involvement in host defense mechanisms against parasites, immunomodulation of the immune system, tissue repair, and angiogenesis. Despite their growing significance in physiological and pathological conditions, much still remains to be learned about mast cell biology. This paper presents evidence that lipid rafts or raft components modulate many of the biological processes in mast cells, such as degranulation and endocytosis, play a role in mast cell development and recruitment, and contribute to the overall preservation of mast cell structure and organization. PMID:21490812

Are mast cells important in diabetes?

PubMed

Kempuraj, Duraisamy; Caraffa, Alessandro; Ronconi, Gianpaolo; Lessiani, Gianfranco; Conti, Pio

Diabetes is a metabolic disorder characterized by hyperglycemia and associated with microvascular and macrovascular syndromes mediated by mast cells. Mast cells are activated through cross-linking of their surface high affinity receptors for IgE (FcRI) or other antigens, leading to degranulation and release of stored inflammatory mediators, and cytokines/chemokines without degranulation. Mast cells are implicated in innate and acquired immunity, inflammation and metabolic disorders such as diabetes. Histamine and tryptase genes in mast cells are overexpressed in pancreatic tissue of type 2 diabetes mellitus (T2DM) patients. Histamine is a classic inflammatory mediator generated by activated receptors of mast cells from the histamine-forming enzyme histidine decarboxylase (HDC), which can be activated by two inflammatory chemokines, RANTES and MPC1, when injected intramuscularly or intradermally in mice. This activation is inhibited in genetically mast cell-deficient W/Wv mice, which show higher insulin sensitivity and glucose tolerance. This study contributes to understanding the mechanism by which mast cells profoundly affect diabetes, and their manipulation could represent a new therapeutic strategy. However, further studies are needed to clarify the role of mast cells in inflammation and metabolic disorders such as diabetes.

Are Mast Cells MASTers in Cancer?

PubMed Central

Varricchi, Gilda; Galdiero, Maria Rosaria; Loffredo, Stefania; Marone, Giancarlo; Iannone, Raffaella; Marone, Gianni; Granata, Francescopaolo

2017-01-01

Prolonged low-grade inflammation or smoldering inflammation is a hallmark of cancer. Mast cells form a heterogeneous population of immune cells with differences in their ultra-structure, morphology, mediator content, and surface receptors. Mast cells are widely distributed throughout all tissues and are stromal components of the inflammatory microenvironment that modulates tumor initiation and development. Although canonically associated with allergic disorders, mast cells are a major source of pro-tumorigenic (e.g., angiogenic and lymphangiogenic factors) and antitumorigenic molecules (e.g., TNF-α and IL-9), depending on the milieu. In certain neoplasias (e.g., gastric, thyroid and Hodgkin’s lymphoma) mast cells play a pro-tumorigenic role, in others (e.g., breast cancer) a protective role, whereas in yet others they are apparently innocent bystanders. These seemingly conflicting results suggest that the role of mast cells and their mediators could be cancer specific. The microlocalization (e.g., peritumoral vs intratumoral) of mast cells is another important aspect in the initiation/progression of solid and hematologic tumors. Increasing evidence in certain experimental models indicates that targeting mast cells and/or their mediators represent a potential therapeutic target in cancer. Thus, mast cells deserve focused consideration also as therapeutic targets in different types of tumors. There are many unanswered questions that should be addressed before we understand whether mast cells are an ally, adversary, or innocent bystanders in human cancers. PMID:28446910

Are Mast Cells MASTers in Cancer?

PubMed

Varricchi, Gilda; Galdiero, Maria Rosaria; Loffredo, Stefania; Marone, Giancarlo; Iannone, Raffaella; Marone, Gianni; Granata, Francescopaolo

2017-01-01

Prolonged low-grade inflammation or smoldering inflammation is a hallmark of cancer. Mast cells form a heterogeneous population of immune cells with differences in their ultra-structure, morphology, mediator content, and surface receptors. Mast cells are widely distributed throughout all tissues and are stromal components of the inflammatory microenvironment that modulates tumor initiation and development. Although canonically associated with allergic disorders, mast cells are a major source of pro-tumorigenic (e.g., angiogenic and lymphangiogenic factors) and antitumorigenic molecules (e.g., TNF-α and IL-9), depending on the milieu. In certain neoplasias (e.g., gastric, thyroid and Hodgkin's lymphoma) mast cells play a pro-tumorigenic role, in others (e.g., breast cancer) a protective role, whereas in yet others they are apparently innocent bystanders. These seemingly conflicting results suggest that the role of mast cells and their mediators could be cancer specific. The microlocalization (e.g., peritumoral vs intratumoral) of mast cells is another important aspect in the initiation/progression of solid and hematologic tumors. Increasing evidence in certain experimental models indicates that targeting mast cells and/or their mediators represent a potential therapeutic target in cancer. Thus, mast cells deserve focused consideration also as therapeutic targets in different types of tumors. There are many unanswered questions that should be addressed before we understand whether mast cells are an ally, adversary, or innocent bystanders in human cancers.

Beyond The Prime Directive: The MAST Discovery Portal and High Level Science Products

NASA Astrophysics Data System (ADS)

Fleming, Scott W.; Abney, Faith; Donaldson, Tom; Dower, Theresa; Fraquelli, Dorothy A.; Koekemoer, Anton M.; Levay, Karen; Matuskey, Jacob; McLean, Brian; Quick, Lee; Rogers, Anthony; Shiao, Bernie; Thompson, Randy; Tseng, Shui-Ay; Wallace, Geoff; White, Richard L.

2015-01-01

The Mikulski Archive for Space Telescopes (MAST) is a NASA-funded archive for a wide range of astronomical missions, primarily supporting space-based UV and optical telescopes. What is less well-known is that MAST provides much more than just a final resting place for primary data products and documentation from these missions. The MAST Discovery Portal is our new search interface that integrates all the missions that MAST supports into a single interface, allowing users to discover (and retrieve) data from other missions that overlap with your targets of interest. In addition to searching MAST, the Portal allows users to search the Virtual Observatory, granting access to data from thousands of collections registered with the VO, including large missions spanning the electromagnetic spectrum (e.g., Chandra, SDSS, Spitzer, 2MASS, WISE). The Portal features table import/export, coordinate-based cross-matching, dynamic chart plotting, and the AstroView sky viewer with footprint overlays. We highlight some of these capabilities with science-driven examples. MAST also accepts High Level Science Products (HLSPs) from the community. These HLSPs are user-generated data products that can be related to a MAST-supported mission. MAST provides a permanent archive for these data with linked references, and integrates it within MAST infrastructure and services. We highlight some of the most recent HLSPs MAST has released, including the HST Frontier Fields, GALEX All-Sky Diffuse Radiation Mapping, a survey of the intergalactic medium with HST-COS, and one of the most complete line lists ever derived for a white dwarf using FUSE AND HST-STIS. These HLSPs generate substantial interest from the community, and are an excellent way to increase visibility and ensure the longevity of your data.

Immunophenotypic characterization of bone marrow mast cells in mastocytosis and other mast cell disorders.

PubMed

Sánchez-Muñoz, Laura; Teodósio, Cristina; Morgado, José M; Escribano, Luis

2011-01-01

Mastocytosis is a term used to designate a heterogeneous group of disorders characterized by an abnormal proliferation and accumulation of mast cells (MCs) in one or multiple tissues including skin, bone marrow (BM), liver, spleen, and lymph nodes, among others. Recent advances in our understanding of mast cell biology and disease resulted in the identification of important differences in the expression of mast cell surface antigens between normal and neoplastic mast cells. Most notably, detection of aberrant expression of CD25 and CD2 on the surface of neoplastic mast cells but not on their normal counterparts lead to the inclusion of this immunophenotypic abnormality in the World Health Organization diagnostic criteria for systemic mastocytosis. Aberrant mast cell surface marker expression can be detected in the bone marrow aspirate by flow cytometry, even in patients lacking histopathologically detectable aggregates of mast cells in bone marrow biopsy sections. These aberrant immunophenotypic features are of great relevance for the assessment of tissue involvement in mastocytosis with consequences in the diagnosis, classification, and follow-up of the disease and in its differential diagnosis with other entities. In this chapter, we provide the reader with information for the objective and reproducible identification of pathologic MCs by using quantitative multiparametric flow cytometry, for their phenotypic characterization, and the criteria currently used for correct interpretation of the immunophenotypic results obtained. Copyright © 2011 Elsevier Inc. All rights reserved.

Pig carcass tail lesions: the influence of record keeping through an advisory service and the relationship with farm performance parameters.

PubMed

van Staaveren, N; Teixeira, D L; Hanlon, A; Boyle, L A

2017-01-01

Tail lesions are important pig welfare indicators that could be recorded during meat inspection as they are more visible on the carcass than on the live animal. Tail biting is associated with reduced performance in the bitten pig, but it is not clear whether problems with tail biting are reflected in general farm performance figures. Farm advisory services aim to improve farm productivity which could be associated with improvements in pig welfare. Record keeping forms an integral part of such advisory services. The aim of this study was to examine the influence of record keeping in the Teagasc eProfit Monitor (ePM herds) on the prevalence of tail lesion severity scores in Irish slaughter pigs. In addition, we investigated associations between the prevalence of tail lesion scores and production parameters at farm level in ePM herds. Pigs were observed after scalding/dehairing and tail lesion score (0 to 4), sex and farm identification were recorded. Tail lesion scores were collapsed into none/mild lesions (score ⩽1), moderate lesions (score 2) and severe lesions (score ⩾3). The effect of record keeping (ePM herd) on the different tail lesion outcomes was analysed at batch level using the events/trials structure in generalized linear mixed models (PROC GLIMMIX). Spearman's rank correlations were calculated between average tail lesion score of a batch and production parameters. A total of 13 133 pigs were assessed from 73 batches coming from 61 farms. In all, 23 farms were identified as ePM herds. The average prevalence of moderate tail lesions was 26.8% and of severe tail lesions was 3.4% in a batch. Batches coming from ePM herds had a lower prevalence of moderate tail lesions than non-ePM herds (P<0.001). Average tail lesion score was negatively associated with age (P<0.05) and weight (P<0.05) at sale/transfer of weaners, and tended to be positively associated with the number of finishing days (P=0.06). In addition, the prevalence of severe tail lesions was

9. DETAIL OF UMBILICAL MAST BASE WITH STEEL STOPS AT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. DETAIL OF UMBILICAL MAST BASE WITH STEEL STOPS AT EAST END OF MOBILE SERVICE STRUCTURE RAIL; VIEW TO NORTHWEST. - Cape Canaveral Air Station, Launch Complex 17, Facility 28501, East end of Lighthouse Road, Cape Canaveral, Brevard County, FL

Mast cells as effectors in atherosclerosis

PubMed Central

Bot, Ilze; Shi, Guo-Ping; Kovanen, Petri T.

2014-01-01

The mast cell is a potent immune cell known for its functions in host defense responses and diseases such as asthma and allergies. In the past years, accumulating evidence established the contribution of the mast cell to cardiovascular diseases as well, in particular by its effects on atherosclerotic plaque progression and destabilization. Through its release of mediators, such as the mast cell-specific proteases chymase and tryptase, but also of growth factors, histamine and chemokines, activated mast cells can have detrimental effects on its immediate surroundings in the vessel wall. This results in matrix degradation, apoptosis and enhanced recruitment of inflammatory cells, thereby actively contributing to cardiovascular diseases. In this review, we will discuss the current knowledge on mast cell function in cardiovascular diseases and speculate on potential novel therapeutic strategies to prevent acute cardiovascular syndromes via targeting of mast cells. PMID:25104798

Thrombopoietin inhibits murine mast cell differentiation

PubMed Central

Martelli, Fabrizio; Ghinassi, Barbara; Lorenzini, Rodolfo; Vannucchi, Alessandro M; Rana, Rosa Alba; Nishikawa, Mitsuo; Partamian, Sandra; Migliaccio, Giovanni; Migliaccio, Anna Rita

2009-01-01

We have recently shown that Mpl, the thrombopoietin receptor, is expressed on murine mast cells and on their precursors and that targeted deletion of the Mpl gene increases mast cell differentiation in mice. Here we report that treatment of mice with thrombopoietin, or addition of this growth factor to bone marrow-derived mast cell cultures, severely hampers the generation of mature cells from their precursors by inducing apoptosis. Analysis of the expression profiling of mast cells obtained in the presence of thrombopoietin suggests that thrombopoietin induces apoptosis of mast cells by reducing expression of the transcription factor Mitf and its target anti-apoptotic gene Bcl2. PMID:18276801

Mast cells as effectors in atherosclerosis.

PubMed

Bot, Ilze; Shi, Guo-Ping; Kovanen, Petri T

2015-02-01

The mast cell is a potent immune cell known for its functions in host defense responses and diseases, such as asthma and allergies. In the past years, accumulating evidence established the contribution of the mast cell to cardiovascular diseases as well, in particular, by its effects on atherosclerotic plaque progression and destabilization. Through its release not only of mediators, such as the mast cell-specific proteases chymase and tryptase, but also of growth factors, histamine, and chemokines, activated mast cells can have detrimental effects on its immediate surroundings in the vessel wall. This results in matrix degradation, apoptosis, and enhanced recruitment of inflammatory cells, thereby actively contributing to cardiovascular diseases. In this review, we will discuss the current knowledge on mast cell function in cardiovascular diseases and speculate on potential novel therapeutic strategies to prevent acute cardiovascular syndromes via targeting of mast cells. © 2014 American Heart Association, Inc.

Somatostatin inhibits intestinal mucosal mast cell degranulation in normal conditions and during mast cell hyperplasia.

PubMed

Saavedra, Y; Vergara, P

2003-03-28

Several studies demonstrate that intestinal mucosal mast cells (IMMC) are modulated by nervous reflexes as well as by intraluminal content. We recently demonstrated that peptones, such as ovalbumin hydrolysate (OVH), induce the release of rat mast cell protease II (RMCP II), indicating IMMC degranulation. The response is due to complex neuroendocrine reflexes. Somatostatin (SS) and its analogues have been used as potential treatments for inflammation in other body systems with contradictory results. The aim of this study was to evaluate if somatostatin could contribute to the reduction of intestinal mucosal mast cell degranulation. Anesthetized rats were prepared for duodenal perfusion and mast cell activation was measured by analysis of RMCP II concentration in the duodenal perfusate. Somatostatin significantly decreased RMCP II concentration in both nonstimulated conditions and after ovalbumin hydrolysate perfusion. However, when somatostatin was given previously to OVH, the peptone still induced a slight increase of RMCP II. Similar effects were observed in animals previously treated with capsaicin. These protocols were repeated in animals infected with Trichinella spiralis, which induces mucosal mast cell hyperplasia. In these cases, somatostatin blocked the effect of OVH, thus, preventing an increase in RMCP II concentration. Fresh frozen tissue sections from the duodenum were processed in an attempt to demonstrate the presence of SS receptors in mast cells using immunofluorescence and Fluo-peptide labeling techniques. Confocal images from duodenum specimens demonstrate the existence of SS receptors in positive cells for RMCP II. Taken together, these results indicate that somatostatin diminishes mast cell activity and in consequence could prevent the intestinal responses to mast cell hyperplasia. Copyright 2002 Elsevier Science B.V.

Mast cell activators as novel immune regulators.

PubMed

Johnson-Weaver, Brandi; Choi, Hae Woong; Abraham, Soman N; Staats, Herman F

2018-05-26

Mast cells are an important cell type of the innate immune system that when activated, play a crucial role in generating protective innate host responses after bacterial and viral infection. Additionally, activated mast cells influence lymph node composition to regulate the induction of adaptive immune responses. The recognition that mast cells play a beneficial role in host responses to microbial infection and induction of adaptive immunity has provided the rationale to evaluate mast cell activators for use as antimicrobials or vaccine adjuvants. This review summarizes the role of mast cell activators in antimicrobial responses while also discussing the use of different classes of mast cell activators as potent vaccine adjuvants that enhance the induction of protective immune responses. Copyright © 2018 Elsevier Ltd. All rights reserved.

Mast cell proteases as pharmacological targets

PubMed Central

Caughey, George H.

2015-01-01

Mast cells are rich in proteases, which are the major proteins of intracellular granules and are released with histamine and heparin by activated cells. Most of these proteases are active in the granule as well outside of the mast cell when secreted, and can cleave targets near degranulating mast cells and in adjoining tissue compartments. Some proteases released from mast cells reach the bloodstream and may have far-reaching actions. In terms of relative amounts, the major mast cell proteases include the tryptases, chymases, cathepsin G, carboxypeptidase A3, dipeptidylpeptidase I/cathepsin C, and cathepsins L and S. Some mast cells also produce granzyme B, plasminogen activators, and matrix metalloproteinases. Tryptases and chymases are almost entirely mast cell-specific, whereas other proteases, such as cathepsins G, C, and L are expressed by a variety of inflammatory cells. Carboxypeptidase A3 expression is a property shared by basophils and mast cells. Other proteases, such as mastins, are largely basophil-specific, although human basophils are protease-deficient compared with their murine counterparts. The major classes of mast cell proteases have been targeted for development of therapeutic inhibitors. Also, a human β-tryptase has been proposed as a potential drug itself, to inactivate of snake venins. Diseases linked to mast cell proteases include allergic diseases, such as asthma, eczema, and anaphylaxis, but also include non-allergic diseases such inflammatory bowel disease, autoimmune arthritis, atherosclerosis, aortic aneurysms, hypertension, myocardial infarction, heart failure, pulmonary hypertension and scarring diseases of lungs and other organs. In some cases, studies performed in mouse models suggest protective or homeostatic roles for specific proteases (or groups of proteases) in infections by bacteria, worms and other parasites, and even in allergic inflammation. At the same time, a clearer picture has emerged of differences in the properties

Dectin-1-mediated signaling leads to characteristic gene expressions and cytokine secretion via spleen tyrosine kinase (Syk) in rat mast cells.

PubMed

Kimura, Yukihiro; Chihara, Kazuyasu; Honjoh, Chisato; Takeuchi, Kenji; Yamauchi, Shota; Yoshiki, Hatsumi; Fujieda, Shigeharu; Sada, Kiyonao

2014-11-07

Dectin-1 recognizes β-glucan and plays important roles for the antifungal immunity through the activation of spleen tyrosine kinase (Syk) in dendritic cells or macrophages. Recently, expression of Dectin-1 was also identified in human and mouse mast cells, although its physiological roles were largely unknown. In this report, rat mast cell line RBL-2H3 was analyzed to investigate the molecular mechanism of Dectin-1-mediated activation and responses of mast cells. Treatment of cells with Dectin-1-specific agonist curdlan induced tyrosine phosphorylation of cellular proteins and the interaction of Dectin-1 with the Src homology 2 domain of Syk. These responses depended on tyrosine phosphorylation of the hemi-immunoreceptor tyrosine-based activation motif in the cytoplasmic tail of Dectin-1, whereas they were independent of the γ-subunit of high-affinity IgE receptor. DNA microarray and real-time PCR analyses showed that Dectin-1-mediated signaling stimulated gene expression of transcription factor Nfkbiz and inflammatory cytokines, such as monocyte chemoattractant protein-1, IL-3, IL-4, IL-13, and tumor necrosis factor (TNF)-α. The response was abrogated by pretreatment with Syk inhibitor R406. These results suggest that Syk is critical for Dectin-1-mediated activation of mast cells, although the signaling differs from that triggered by FcϵRI activation. In addition, these gene expressions induced by curdlan stimulation were specifically observed in mast cells, suggesting that Dectin-1-mediated signaling of mast cells offers new insight into the antifungal immunity. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Mast Cells in Allergic Diseases and Mastocytosis

PubMed Central

Marquardt, Diana L.; Wasserman, Stephen I.

1982-01-01

Mast cells with their stores of vasoactive and chemotactic mediators are central to the pathogenesis of allergic diseases. The cross-linking of receptorbound IgE molecules on the surface of mast cells initiates a complex chain of events, including calcium ion influx, phospholipid methylation and turnover and cyclic nucleotide metabolism, ultimately resulting in the release of mediators of immediate hypersensitivity. These mast cell mediators are important in smooth muscle reactivity, in the recruitment of eosinophilic and neutrophilic leukocytes and in the generation of secondary chemical mediators. Histologic evidence of mast cell degranulation, biochemical evidence of mast cell mediators in blood and tissues and clinical evidence of signs and symptoms reproducible by these mediators have strongly supported the crucial role of mast cells in asthma, urticaria, anaphylaxis, rhinitis and mastocytosis. Because of their unique location at host environment interfaces, mast cells may both participate in allergic diseases and promote homeostasis. ImagesFigure 1.Figure 2.Figure 3. PMID:6293204

Mast Cells Produce a Unique Chondroitin Sulfate Epitope.

PubMed

Farrugia, Brooke L; Whitelock, John M; O'Grady, Robert; Caterson, Bruce; Lord, Megan S

2016-02-01

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. © 2016 The Histochemical Society.

30 CFR 57.7004 - Drill mast.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drill mast. 57.7004 Section 57.7004 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling-Surface Only § 57.7004 Drill mast. Persons shall not be on a mast while the drill-bit is in...

30 CFR 56.7004 - Drill mast.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drill mast. 56.7004 Section 56.7004 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling § 56.7004 Drill mast. Persons shall not be on a mast while the drill-bit is in operation unless...

30 CFR 56.7004 - Drill mast.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Drill mast. 56.7004 Section 56.7004 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling § 56.7004 Drill mast. Persons shall not be on a mast while the drill-bit is in operation unless...

30 CFR 57.7004 - Drill mast.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Drill mast. 57.7004 Section 57.7004 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling-Surface Only § 57.7004 Drill mast. Persons shall not be on a mast while the drill-bit is in...

30 CFR 57.7004 - Drill mast.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Drill mast. 57.7004 Section 57.7004 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling-Surface Only § 57.7004 Drill mast. Persons shall not be on a mast while the drill-bit is in...

30 CFR 57.7004 - Drill mast.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Drill mast. 57.7004 Section 57.7004 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling-Surface Only § 57.7004 Drill mast. Persons shall not be on a mast while the drill-bit is in...

30 CFR 56.7004 - Drill mast.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Drill mast. 56.7004 Section 56.7004 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling § 56.7004 Drill mast. Persons shall not be on a mast while the drill-bit is in operation unless...

30 CFR 56.7004 - Drill mast.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Drill mast. 56.7004 Section 56.7004 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling § 56.7004 Drill mast. Persons shall not be on a mast while the drill-bit is in operation unless...

30 CFR 56.7004 - Drill mast.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Drill mast. 56.7004 Section 56.7004 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling § 56.7004 Drill mast. Persons shall not be on a mast while the drill-bit is in operation unless...

30 CFR 57.7004 - Drill mast.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Drill mast. 57.7004 Section 57.7004 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling-Surface Only § 57.7004 Drill mast. Persons shall not be on a mast while the drill-bit is in...

Mast cells promote melanoma colonization of lungs.

PubMed

Öhrvik, Helena; Grujic, Mirjana; Waern, Ida; Gustafson, Ann-Marie; Ernst, Nancy; Roers, Axel; Hartmann, Karin; Pejler, Gunnar

2016-10-18

Mast cells have been implicated in malignant processes, mainly through clinical correlative studies and by experiments performed using animals lacking mast cells due to defective c-kit signaling. However, mast cell-deficient mouse models based on c-kit defects have recently been questioned for their relevance. Here we addressed the effect of mast cells in a tumor setting by using transgenic Mcpt5-Cre+ R-DTA+ mice, in which the deficiency of mast cells is independent of c-kit defects. Melanoma cells (B16.F10) were administered either subcutaneously or intravenously into Mcpt5-Cre+ R-DTA+ mice or Mcpt5-Cre- R-DTA+ littermate controls, followed by the assessment of formed tumors. In the subcutaneous model, mast cells were abundant in the tumor stroma of control mice but were absent in Mcpt5-Cre+ R-DTA+ mice. However, the absence of mast cells did not affect tumor size. In contrast, after intravenous administration of B16.F10 cells, melanoma colonization of the lungs was markedly reduced in Mcpt5-Cre+ R-DTA+ vs. Mcpt5-Cre- R-DTA+ animals. Decreased melanoma colonization of the lungs in Mcpt5-Cre+ R-DTA+ animals was accompanied by increased inflammatory cell recruitment into the bronchoalveolar lavage fluid, suggesting that mast cells suppress inflammation in this setting. Further, qPCR analysis revealed significant alterations in the expression of Twist and E-cadherin in lungs of Mcpt5-Cre+ R-DTA+ vs. control Mcpt5-Cre- R-DTA+ animals, suggesting an impact of mast cells on epithelial-mesenchymal transition. In conclusion, this study reveals that mast cells promote melanoma colonization of the lung.

Mast cells and company.

PubMed

Jönsson, Friederike; Daëron, Marc

2012-01-01

Classically, allergy depends on IgE antibodies and on high-affinity IgE receptors expressed by mast cells and basophils. This long accepted IgE/FcεRI/mast cell paradigm, on which the definition of immediate hypersensitivity was based in the Gell and Coomb's classification, appears too reductionist. Recently accumulated evidence indeed requires that not only IgE but also IgG antibodies, that not only FcεRI but also FcγR of the different types, that not only mast cells and basophils but also neutrophils, monocytes, macrophages, eosinophils, and other myeloid cells be considered as important players in allergy. This view markedly changes our understanding of allergic diseases and, possibly, their treatment.

Mast Cells Synthesize, Store, and Release Nerve Growth Factor

NASA Astrophysics Data System (ADS)

Leon, A.; Buriani, A.; dal Toso, R.; Fabris, M.; Romanello, S.; Aloe, L.; Levi-Montalcini, R.

1994-04-01

Mast cells and nerve growth factor (NGF) have both been reported to be involved in neuroimmune interactions and tissue inflammation. In many peripheral tissues, mast cells interact with the innervating fibers. Changes in the behaviors of both of these elements occur after tissue injury/inflammation. As such conditions are typically associated with rapid mast cell activation and NGF accumulation in inflammatory exudates, we hypothesized that mast cells may be capable of producing NGF. Here we report that (i) NGF mRNA is expressed in adult rat peritoneal mast cells; (ii) anti-NGF antibodies clearly stain vesicular compartments of purified mast cells and mast cells in histological sections of adult rodent mesenchymal tissues; and (iii) medium conditioned by peritoneal mast cells contains biologically active NGF. Mast cells thus represent a newly recognized source of NGF. The known actions of NGF on peripheral nerve fibers and immune cells suggest that mast cell-derived NGF may control adaptive/reactive responses of the nervous and immune systems toward noxious tissue perturbations. Conversely, alterations in normal mast cell behaviors may provoke maladaptive neuroimmune tissue responses whose consequences could have profound implications in inflammatory disease states, including those of an autoimmune nature.

The emerging role of mast cells in liver disease.

PubMed

Jarido, Veronica; Kennedy, Lindsey; Hargrove, Laura; Demieville, Jennifer; Thomson, Joanne; Stephenson, Kristen; Francis, Heather

2017-08-01

The depth of our knowledge regarding mast cells has widened exponentially in the last 20 years. Once thought to be only important for allergy-mediated events, mast cells are now recognized to be important regulators of a number of pathological processes. The revelation that mast cells can influence organs, tissues, and cells has increased interest in mast cell research during liver disease. The purpose of this review is to refresh the reader's knowledge of the development, type, and location of mast cells and to review recent work that demonstrates the role of hepatic mast cells during diseased states. This review focuses primarily on liver diseases and mast cells during autoimmune disease, hepatitis, fatty liver disease, liver cancer, and aging in the liver. Overall, these studies demonstrate the potential role of mast cells in disease progression.

Distribution and characterisation of rat choroidal mast cells.

PubMed Central

Steptoe, R J; McMenamin, P G; McMenamin, C

1994-01-01

Despite the implication that choroidal mast cells are involved in the onset of experimental autoimmune uveoretinitis (EAU), a widely used animal model of uveoretinitis, little is known of these cells. In the present study the distribution, total number, regional density, and phenotype of choroidal mast cells were examined in Lewis, Wistar Furth, PVG/c, and brown Norway rats. Choroidal mast cells were predominantly associated with arteries and arterioles of more than 30 microns diameter which lie in the outer (sclerad) choroid. The density of mast cells was greatest in the posterior choroid with density diminishing anteriorly. The choroid of male Lewis rats contained significantly greater number of mast cells than that of females (p < 0.01). Histochemical (Alcian blue/safranin) and immunohistochemical (anti-rat mast cell protease I and II monoclonal antibodies) studies revealed choroidal mast cells were of the connective tissue type. However, granule proteinase content appeared less than that of well characterised connective tissue mast cell populations such as those in mesentery and skin. Lewis rats exhibited the highest density of choroidal mast cells (23.6 (SD 1.2)/mm2), Wistar Furth approximately half that of Lewis (13.5 (0.7)/mm2) while PVG/c and brown Norway rats had very low densities (3.06(0.3); 1.95(0.2/mm2 respectively). These studies provide valuable choroidal mast cell data for rats which may have implications for our understanding of experimental models of intraocular inflammation and clinical uveitis. Images PMID:8148338

Pavlovian Conditioning of Rat Mucosal Mast Cells to Secrete Rat Mast Cell Protease II

NASA Astrophysics Data System (ADS)

MacQueen, Glenda; Marshall, Jean; Perdue, Mary; Siegel, Shepard; Bienenstock, John

1989-01-01

Antigen (egg albumin) injections, which stimulate mucosal mast cells to secrete mediators, were paired with an audiovisual cue. After reexposure to the audiovisual cue, a mediator (rat mast cell protease II) was measured with a sensitive and specific assay. Animals reexposed to only the audiovisual cue released a quantity of protease not significantly different from animals reexposed to both the cue and the antigen; these groups released significantly more protease than animals that had received the cue and antigen in a noncontingent manner. The results support a role for the central nervous system as a functional effector of mast cell function in the allergic state.

Vitamin E and mast cells.

PubMed

Zingg, Jean-Marc

2007-01-01

Mast cells play an important role in the immune system by interacting with B and T cells and by releasing several mediators involved in activating other cells. Hyperreactivity of mast cells and their uncontrolled accumulation in tissues lead to increased release of inflammatory mediators contributing to the pathogenesis of several diseases such as rheumatoid arthritis, atherosclerosis, multiple sclerosis, and allergic disorders such as asthma and allergic rhinitis. Interference with mast cell proliferation, survival, degranulation, and migration by synthetic or natural compounds may represent a preventive strategy for the management of these diseases. Natural vitamin E covers a group of eight analogues-the alpha-, beta-, gamma-, and delta-tocopherols and the alpha-, beta-, gamma-, and delta-tocotrienols, but only alpha-tocopherol is efficiently retained by the liver and distributed to peripheral tissues. Mast cells preferentially locate in the proximity of tissues that interface with the external environment (the epithelial surface of the skin, the gastrointestinal mucosa, and the respiratory system), what may render them accessible to treatments with inefficiently retained natural vitamin E analogues and synthetic derivatives. In addition to scavenging free radicals, the natural vitamin E analogues differently modulate signal transduction and gene expression in several cell lines; in mast cells, protein kinase C, protein phosphatase 2A, and protein kinase B are affected by vitamin E, leading to the modulation of proliferation, apoptosis, secretion, and migration. In this chapter, the possibility that vitamin E can prevent diseases with mast cells involvement by modulating signal transduction and gene expression is evaluated.

Eosinophilic Esophagitis: Relevance of Mast Cell Infiltration.

PubMed

Strasser, Daniel S; Seger, Shanon; Bussmann, Christian; Pierlot, Gabin M; Groenen, Peter M A; Stalder, Anna K; Straumann, Alex

2018-05-17

Eosinophilic esophagitis (EoE) is a chronic-inflammatory disease characterized clinically by symptoms of esophageal dysfunction and histopathologically by a prominent eosinophilic inflammation. Despite eosinophils having histologically a pre-dominant position, their role in the immunopathogenesis of the disease is still questionable. Several other inflammatory cells are involved and may play a critical role as well. The purpose of this study was to characterize the mast cell infiltration, and to correlate it with clinical state of EoE. Using immunohistochemistry and quantitative morphometry, we extensively investigated eosinophils and mast cells in esophageal biopsies from patients with active EoE and from patients with EoE in remission, and compared the findings with healthy individuals. In EoE, epithelium and lamina propria were similarly infiltrated with eosinophils. In contrast, mast cells infiltration was limited to the epithelium, displaying a localized immune response. Interestingly, whereas epithelial mast cells and eosinophils were high in active EoE, some patients in remission e.g. normalized epithelial eosinophils, showed remaining high numbers of mast cells. Patient clustering supported 2 groups of patients in clinical remission, differentiating based on presence or absence of epithelial mast cells. Active EoE is characterized - in addition to the well-known tissue eosinophilia by a marked epithelium-restricted mast cell infiltration. Of interest, in a subgroup of patients, mast cell infiltration persisted despite clinical remission. To elucidate the clinical consequence of persistent epithelial mast cells infiltration further studies are required following patients in clinical remission longitudinally. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

KSC01PD1744

NASA Image and Video Library

2001-11-28

KENNEDY SPACE CENTER, Fla. -- Space Shuttle Endeavour stands ready for launch after rollback of the Rotating Service Structure on Launch Pad 39B. Seen are the twin solid rocket boosters flanking the orange external tank. Stretching to the crew hatch on the side is the Orbiter Access Arm with its environmentally controlled White Room at the end. Below Endeavour is the Mobile Launcher Platform with the two service tail masts on either side of the main engines. The tail masts support the fluid, gas and electrical requirements of the orbiter's liquid oxygen and liquid hydrogen aft T-0 umbilicals. Each tail mast is 31 feet (9.4 meters) high, 15 feet (4.6 meters) long and 9 feet (3.1 meters) wide. Endeavour is scheduled to launch on mission STS-108 Nov. 29 at 7:41 p.m. On this 12th flight to the International Space Station, known as a Utilization Flight, Endeavour will carry a crew of four plus the Expedition 4 crew, who will replace Expedition 3 aboard the ISS. The payload includes the Multi-Purpose Logistics Module Raffaello, filled with supplies, equipment and experiments

Mast Cell Proteases as Protective and Inflammatory Mediators

PubMed Central

Caughey, George H.

2014-01-01

Proteases are the most abundant class of proteins produced by mast cells. Many of these are stored in membrane-enclosed intracellular granules until liberated by degranulating stimuli, which include cross-linking of high affinity IgE receptor FcεRI by IgE bound to multivalent allergen. Understanding and separating the functions of the proteases is important because expression differs among mast cells in different tissue locations. Differences between laboratory animals and humans in protease expression also influence the degree of confidence with which results obtained in animal models of mast cell function can be extrapolated to humans. The inflammatory potential of mast cell proteases was the first aspect of their biology to be explored and has received the most attention, in part because some of them—notably tryptases and chymases—are biomarkers of local and systemic mast cell degranulation and anaphylaxis. Although some of the proteases indeed augment allergic inflammation and are potential targets for inhibition to treat asthma and related allergic disorders, they are protective and even anti-inflammatory in some settings. For example, mast cell tryptases may protect from serious bacterial lung infections and may limit the “rubor” component of inflammation caused by vasodilating neuropeptides in the skin. Chymases help to maintain intestinal barrier function and to expel parasitic worms, and may support blood pressure during anaphylaxis by generating angiotensin II. In other life-or-death examples, carboxypeptidase A3 and other mast cell peptidases limit systemic toxicity of endogenous peptides like endothelin and neurotensin during septic peritonitis, and inactivate venom-associated peptides. On the other hand, mast cell peptidase-mediated destruction of protective cytokines, like IL-6, can enhance mortality from sepsis. Peptidases released from mast cells also influence non-mast cell proteases, such as by activating matrix metalloproteinase cascades

Phaeton Mast Dynamics: On-Orbit Characterization of Deployable Masts

NASA Technical Reports Server (NTRS)

Michaels, Darren J.

2011-01-01

The PMD instrument is a set of three custom-designed triaxial accelerometer systems designed specifically to detect and characterize the modal dynamics of deployable masts in orbit. The instrument was designed and built as a payload for the NuSTAR spacecraft, but it is now sponsored by the Air Force Research Laboratory's DSX project. It can detect acceleration levels from 1 micro gram to 0.12g over a frequency range of 0.1Hz to 30Hz, the results of which can support future modeling and designing of deployable mast structures for space. This paper details the hardware architecture and design, calibration test and results, and current status of the PMD instrument.

Diverse exocytic pathways for mast cell mediators.

PubMed

Xu, Hao; Bin, Na-Ryum; Sugita, Shuzo

2018-04-17

Mast cells play pivotal roles in innate and adaptive immunities but are also culprits in allergy, autoimmunity, and cardiovascular diseases. Mast cells respond to environmental changes by initiating regulated exocytosis/secretion of various biologically active compounds called mediators (e.g. proteases, amines, and cytokines). Many of these mediators are stored in granules/lysosomes and rely on intricate degranulation processes for release. Mast cell stabilizers (e.g. sodium cromoglicate), which prevent such degranulation processes, have therefore been clinically employed to treat asthma and allergic rhinitis. However, it has become increasingly clear that different mast cell diseases often involve multiple mediators that rely on overlapping but distinct mechanisms for release. This review illustrates existing evidence that highlights the diverse exocytic pathways in mast cells. We also discuss strategies to delineate these pathways so as to identify unique molecular components which could serve as new drug targets for more effective and specific treatments against mast cell-related diseases. © 2018 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Recombinant ArtinM activates mast cells.

PubMed

Barbosa-Lorenzi, Valéria Cintra; Cecilio, Nerry Tatiana; de Almeida Buranello, Patricia Andressa; Pranchevicius, Maria Cristina; Goldman, Maria Helena S; Pereira-da-Silva, Gabriela; Roque-Barreira, Maria Cristina; Jamur, Maria Célia; Oliver, Constance

2016-07-04

Mast cells are hematopoietically derived cells that play a role in inflammatory processes such as allergy, as well as in the immune response against pathogens by the selective and rapid release of preformed and lipid mediators, and the delayed release of cytokines. The native homotetrameric lectin ArtinM, a D-mannose binding lectin purified from Artocarpus heterophyllus seeds, is one of several lectins that are able to activate mast cells. Besides activating mast cells, ArtinM has been shown to affect several biological responses, including immunomodulation and acceleration of wound healing. Because of the potential pharmacological application of ArtinM, a recombinant ArtinM (rArtinM) was produced in Escherichia coli. The current study evaluated the ability of rArtinM to induce mast cell degranulation and activation. The glycan binding specificity of rArtinM was similar to that of jArtinM. rArtinM, via its CRD, was able to degranulate, releasing β-hexosaminidase and TNF-α, and to promote morphological changes on the mast cell surface. Moreover, rArtinM induced the release of the newly-synthesized mediator, IL-4. rArtinM does not have a co-stimulatory effect on the FcεRI degranulation via. The IgE-dependent mast cell activation triggered by rArtinM seems to be dependent on NFkB activation. The lectin rArtinM has the ability to activate and degranulate mast cells via their CRDs. The present study indicates that rArtinM is a suitable substitute for the native form, jArtinM, and that rArtinM may serve as an important and reliable pharmacological agent.

Illustrating MastCam Capabilities with a Terrestrial Scene

NASA Image and Video Library

2011-11-28

This set of views illustrates capabilities of the Mast Camera MastCam instrument on NASA Mars Science Laboratory Curiosity rover, using a scene on Earth as an example of what MastCam two cameras can see from different distances.

Regulatory roles of mast cells in immune responses.

PubMed

Morita, Hideaki; Saito, Hirohisa; Matsumoto, Kenji; Nakae, Susumu

2016-09-01

Mast cells are important immune cells for host defense through activation of innate immunity (via toll-like receptors or complement receptors) and acquired immunity (via FcεRI). Conversely, mast cells also act as effector cells that exacerbate development of allergic or autoimmune disorders. Yet, several lines of evidence show that mast cells act as regulatory cells to suppress certain inflammatory diseases. Here, we review the mechanisms by which mast cells suppress diseases.

Cytoskeleton in Mast Cell Signaling

PubMed Central

Dráber, Pavel; Sulimenko, Vadym; Dráberová, Eduarda

2012-01-01

Mast cell activation mediated by the high affinity receptor for IgE (FcεRI) is a key event in allergic response and inflammation. Other receptors on mast cells, as c-Kit for stem cell factor and G protein-coupled receptors (GPCRs) synergistically enhance the FcεRI-mediated release of inflammatory mediators. Activation of various signaling pathways in mast cells results in changes in cell morphology, adhesion to substrate, exocytosis, and migration. Reorganization of cytoskeleton is pivotal in all these processes. Cytoskeletal proteins also play an important role in initial stages of FcεRI and other surface receptors induced triggering. Highly dynamic microtubules formed by αβ-tubulin dimers as well as microfilaments build up from polymerized actin are affected in activated cells by kinases/phosphatases, Rho GTPases and changes in concentration of cytosolic Ca2+. Also important are nucleation proteins; the γ-tubulin complexes in case of microtubules or Arp 2/3 complex with its nucleation promoting factors and formins in case of microfilaments. The dynamic nature of microtubules and microfilaments in activated cells depends on many associated/regulatory proteins. Changes in rigidity of activated mast cells reflect changes in intermediate filaments build up from vimentin. This review offers a critical appraisal of current knowledge on the role of cytoskeleton in mast cells signaling. PMID:22654883

Mast Cell Peptidases

PubMed Central

Trivedi, Neil N.; Caughey, George H.

2010-01-01

Mast cells make and secrete an abundance of peptidases, which are stored in such large amounts in granules that they comprise a high fraction of all cellular protein. Perhaps no other immune cell is so generously endowed with peptidases. For many years after the main peptidases were first described, they were best known as markers of degranulation, for they are released locally in response to mast cell stimulation and can be distributed systemically and detected in blood. The principal peptidases are tryptases, chymases, carboxypeptidase A3, and dipeptidylpeptidase I (cathepsin C). Numerous studies suggest that these enzymes are important and even critical for host defense and homeostasis. Endogenous and allergen or pathogen-associated targets have been identified. Belying the narrow notion of peptidases as proinflammatory, several of the peptidases limit inflammation and toxicity of endogenous peptides and venoms. The peptidases are interdependent, so that absence or inactivity of one enzyme can alter levels and activity of others. Mammalian mast cell peptidases—chymases and tryptases especially—vary remarkably in number, expression, biophysical properties, and specificity, perhaps because they hyper-evolved under pressure from the very pathogens they help to repel. Tryptase and chymase involvement in some pathologies stimulated development of therapeutic inhibitors for use in asthma, lung fibrosis, pulmonary hypertension, ulcerative colitis, and cardiovascular diseases. While animal studies support the potential for mast cell peptidase inhibitors to mitigate certain diseases, other studies, as in mice lacking selected peptidases, predict roles in defense against bacteria and parasites and that systemic inactivation may impair host defense. PMID:19933375

Mast cells mediate neutrophil recruitment during atherosclerotic plaque progression.

PubMed

Wezel, Anouk; Lagraauw, H Maxime; van der Velden, Daniël; de Jager, Saskia C A; Quax, Paul H A; Kuiper, Johan; Bot, Ilze

2015-08-01

Activated mast cells have been identified in the intima and perivascular tissue of human atherosclerotic plaques. As mast cells have been described to release a number of chemokines that mediate leukocyte fluxes, we propose that activated mast cells may play a pivotal role in leukocyte recruitment during atherosclerotic plaque progression. Systemic IgE-mediated mast cell activation in apoE(-/-)μMT mice resulted in an increase in atherosclerotic lesion size as compared to control mice, and interestingly, the number of neutrophils was highly increased in these lesions. In addition, peritoneal mast cell activation led to a massive neutrophil influx into the peritoneal cavity in C57Bl6 mice, whereas neutrophil numbers in mast cell deficient Kit(W(-sh)/W(-sh)) mice were not affected. Within the newly recruited neutrophil population, increased levels of CXCR2(+) and CXCR4(+) neutrophils were observed after mast cell activation. Indeed, mast cells were seen to contain and release CXCL1 and CXCL12, the ligands for CXCR2 and CXCR4. Intriguingly, peritoneal mast cell activation in combination with anti-CXCR2 receptor antagonist resulted in decreased neutrophil recruitment, thus establishing a prominent role for the CXCL1/CXCR2 axis in mast cell-mediated neutrophil recruitment. Our data suggest that chemokines, and in particular CXCL1, released from activated mast cells induce neutrophil recruitment to the site of inflammation, thereby aggravating the ongoing inflammatory response and thus affecting plaque progression and destabilization. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Mast cell proteases as protective and inflammatory mediators.

PubMed

Caughey, George H

2011-01-01

Proteases are the most abundant class of proteins produced by mast cells. Many of these are stored in membrane-enclosed intracellular granules until liberated by degranulating stimuli, which include cross-linking of high affinity IgE receptor F(c)εRI by IgE bound to multivalent allergen. Understanding and separating the functions of the proteases is important because expression differs among mast cells in different tissue locations. Differences between laboratory animals and humans in protease expression also influence the degree of confidence with which results obtained in animal models of mast cell function can be extrapolated to humans. The inflammatory potential of mast cell proteases was the first aspect of their biology to be explored and has received the most attention, in part because some of them, notably tryptases and chymases, are biomarkers of local and systemic mast cell degranulation and anaphylaxis. Although some of the proteases indeed augment allergic inflammation and are potential targets for inhibition to treat asthma and related allergic disorders, they are protective and even anti-inflammatory in some settings. For example, mast cell tryptases may protect from serious bacterial lung infections and may limit the "rubor" component of inflammation caused by vasodilating neuropeptides in the skin. Chymases help to maintain intestinal barrier function and to expel parasitic worms and may support blood pressure during anaphylaxis by generating angiotensin II. In other life-or-death examples, carboxypeptidase A3 and other mast cell peptidases limit systemic toxicity of endogenous peptideslike endothelin and neurotensin during septic peritonitis and inactivate venom-associated peptides. On the other hand, mast cell peptidase-mediated destruction of protective cytokines, like IL-6, can enhance mortality from sepsis. Peptidases released from mast cells also influence nonmast cell proteases, such as by activating matrix metalloproteinase cascades, which

Mast Cells: Pivotal Players in Cardiovascular Diseases

PubMed Central

Bot, Ilze; van Berkel, Theo J.C; Biessen, Erik A.L

2008-01-01

The clinical outcome of cardiovascular diseases as myocardial infarction and stroke are generally caused by rupture of an atherosclerotic plaque. However, the actual cause of a plaque to rupture is not yet established. Interestingly, pathology studies have shown an increased presence of the mast cell, an important inflammatory effector cell in allergy and host defense, in (peri)vascular tissue during plaque progression, which may point towards a causal role for mast cells. Very recent data in mouse models show that mast cells and derived mediators indeed can profoundly impact plaque progression, plaque stability and acute cardiovascular syndromes such as vascular aneurysm or myocardial infarction. In this review, we discuss recent evidence on the role of mast cells in the progression of cardiovascular disorders and give insight in the therapeutic potential of modulation of mast cell function in these processes to improve the resilience of a plaque to rupture. PMID:19936193

Biomarkers for evaluation of mast cell and basophil activation.

PubMed

Kabashima, Kenji; Nakashima, Chisa; Nonomura, Yumi; Otsuka, Atsushi; Cardamone, Chiara; Parente, Roberta; De Feo, Giulia; Triggiani, Massimo

2018-03-01

Mast cells and basophils play a pathogenetic role in allergic, inflammatory, and autoimmune disorders. These cells have different development, anatomical location and life span but share many similarities in mechanisms of activation and type of mediators. Mediators secreted by mast cells and basophils correlate with clinical severity in asthma, chronic urticaria, anaphylaxis, and other diseases. Therefore, effective biomarkers to measure mast cell and basophil activation in vivo could potentially have high diagnostic and prognostic values. An ideal biomarker should be specific for mast cells or basophils, easily and reproducibly detectable in blood or biological fluids and should be metabolically stable. Markers of mast cell and basophil include molecules secreted by stimulated cells and surface molecules expressed upon activation. Some markers, such as histamine and lipid mediators are common to mast cells and basophils whereas others, such as tryptase and other proteases, are relatively specific for mast cells. The best surface markers of activation expressed on mast cells and basophils are CD63 and CD203. While these mediators and surface molecules have been associated to a variety of diseases, none of them fulfills requirements for an optimal biomarker and search for better indicators of mast cell/basophil activation in vivo is ongoing. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effects of Secreted Mast Cell Mediators on Retinal Pigment Epithelial Cells: Focus on Mast Cell Tryptase.

PubMed

Arai, Rei; Usui-Ouchi, Ayumi; Ito, Yosuke; Mashimo, Keitaro; Murakami, Akira; Ebihara, Nobuyuki

2017-01-01

Numerous mast cells are present in the choroid, but the effects of mast cell mediators on retinal pigment epithelial (RPE) cells are not well understood. We investigated the influence of mast cell mediators on RPE cells in vitro, focusing on tryptase. Expression of receptors was examined by the reverse transcription polymerase chain reaction. We also assessed production of interleukin 8 and vascular endothelial growth factor (VEGF) after RPE cells were stimulated with mast cell mediators by using an antibody array and enzyme-linked immunosorbent assay. Furthermore, we investigated the influence of tryptase on RPE cell migration and integrity by the scratch assay and the transepithelial resistance. RPE cells expressed protease-activated receptor 2 (PAR2), histamine receptor 1, tumor necrosis factor- α (TNF- α ) receptor 1, and CCR 1, 3, 4, 8, and 11. Tryptase, PAR2 agonists, histamine, and TNF- α all enhanced interleukin 8 production by RPE cells, while only tryptase enhanced VEGF production. Tryptase also enhanced expression of phosphorylated extracellular signal-regulated kinases 1/2, resulting in increased migration of RPE cells. However, tryptase did not alter epithelial integrity or the expression of zonula occludens-1 and junctional adhesion molecule-A by RPE cells. Mast cell mediators, especially tryptase, may influence RPE cell inflammation.

Subthreshold IKK activation modulates the effector functions of primary mast cells and allows specific targeting of transformed mast cells

PubMed Central

Drube, Sebastian; Beyer, Mandy; Rothe, Mandy; Rabenhorst, Anja; Göpfert, Christiane; Meininger, Isabel; Diamanti, Michaela A.; Stegner, David; Häfner, Norman; Böttcher, Martin; Reinecke, Kirstin; Herdegen, Thomas; Greten, Florian R.; Nieswandt, Bernhard; Hartmann, Karin; Krämer, Oliver H.; Kamradt, Thomas

2015-01-01

Mast cell differentiation and proliferation depends on IL-3. IL-3 induces the activation of MAP-kinases and STATs and consequently induces proliferation and survival. Dysregulation of IL-3 signaling pathways also contribute to inflammation and tumorigenesis. We show here that IL-3 induces a SFK- and Ca2+-dependent activation of the inhibitor of κB kinases 2 (IKK2) which results in mast cell proliferation and survival but does not induce IκBα-degradation and NFκB activation. Therefore we propose the term “subthreshold IKK activation”. This subthreshold IKK activation also primes mast cells for enhanced responsiveness to IL-33R signaling. Consequently, co-stimulation with IL-3 and IL-33 increases IKK activation and massively enhances cytokine production induced by IL-33. We further reveal that in neoplastic mast cells expressing constitutively active Ras, subthreshold IKK activation is associated with uncontrolled proliferation. Consequently, pharmacological IKK inhibition reduces tumor growth selectively by inducing apoptosis in vivo. Together, subthreshold IKK activation is crucial to mediate the full IL-33-induced effector functions in primary mast cells and to mediate uncontrolled proliferation of neoplastic mast cells. Thus, IKK2 is a new molecularly defined target structure. PMID:25749030

Controversial role of mast cells in skin cancers.

PubMed

Varricchi, Gilda; Galdiero, Maria R; Marone, Giancarlo; Granata, Francescopaolo; Borriello, Francesco; Marone, Gianni

2017-01-01

Cancer development is a multistep process characterized by genetic and epigenetic alterations during tumor initiation and progression. The stromal microenvironment can promote tumor development. Mast cells, widely distributed throughout all tissues, are a stromal component of many solid and haematologic tumors. Mast cells can be found in human and mouse models of skin cancers such as melanoma, basal and squamous cell carcinomas, primary cutaneous lymphomas, haemangiomas and Merkel cell carcinoma. However, human and animal studies addressing potential functions of mast cells and their mediators in skin cancers have provided conflicting results. In several studies, mast cells play a pro-tumorigenic role, whereas in others, they play an anti-tumorigenic role. Other studies have failed to demonstrate a clear role for tumor-associated mast cells. Many unanswered questions need to be addressed before we understand whether tumor-associated mast cells are adversaries, allies or simply innocent bystanders in different types and subtypes of skin cancers. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Mast cells in airway diseases and interstitial lung disease.

PubMed

Cruse, Glenn; Bradding, Peter

2016-05-05

Mast cells are major effector cells of inflammation and there is strong evidence that mast cells play a significant role in asthma pathophysiology. There is also a growing body of evidence that mast cells contribute to other inflammatory and fibrotic lung diseases such as chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis. This review discusses the role that mast cells play in airway diseases and highlights how mast cell microlocalisation within specific lung compartments and their cellular interactions are likely to be critical for their effector function in disease. Published by Elsevier B.V.

Loss of histochemical identity in mast cells lacking carboxypeptidase A.

PubMed

Feyerabend, Thorsten B; Hausser, Heinz; Tietz, Annette; Blum, Carmen; Hellman, Lars; Straus, Anita H; Takahashi, Hélio K; Morgan, Ellen S; Dvorak, Ann M; Fehling, Hans Jörg; Rodewald, Hans-Reimer

2005-07-01

Mast cell carboxypeptidase A (Mc-cpa) is a highly conserved secretory granule protease. The onset of expression in mast cell progenitors and lineage specificity suggest an important role for Mc-cpa in mast cells. To address the function of Mc-cpa, we generated Mc-cpa-null mice. Mc-cpa-/- mast cells lacked carboxypeptidase activity, revealing that Mc-cpa is a nonredundant enzyme. While Mc-cpa-/- peritoneal mast cells were ultrastructurally normal and synthesized normal amounts of heparin, they displayed striking histochemical and biochemical hallmarks of immature mast cells. Wild-type peritoneal mast cells had a mature phenotype characterized by differential histochemical staining with proteoglycan-reactive dyes (cells do not stain with alcian blue but stain with safranin and with berberine) and a high side scatter to forward scatter ratio by flow cytometry and were detergent resistant. In contrast, Mc-cpa-/- peritoneal mast cells, like immature bone marrow-derived cultured mast cells, stained with alcian blue normally or weakly and either did not stain with safranin and berberine or stained weakly, had a low side scatter to forward scatter ratio, and were detergent sensitive. This phenotype was partially ameliorated with age. Thus, histochemistry and flow cytometry, commonly used to measure mast cell maturation, deviated from morphology in Mc-cpa-/- mice. The Mc-cpa-/- mast cell phenotype was not associated with defects in degranulation in vitro or passive cutaneous anaphylaxis in vivo. Collectively, Mc-cpa plays a crucial role for the generation of phenotypically mature mast cells.

Role of thrombopoietin in mast cell differentiation.

PubMed

Migliaccio, Anna Rita; Rana, Rosa Alba; Vannucchi, Alessandro M; Manzoli, Francesco A

2007-06-01

Mast cells are important elements of the body response to foreign antigens, being those represented either by small molecules (allergic response) or harbored by foreign microorganisms (response to parasite infection). These cells derive from hematopoietic stem/progenitor cells present in the marrow. However, in contrast with most of the other hematopoietic lineages, mast cells do not differentiate in the marrow but in highly vascularized extramedullary sites, such as the skin or the gut. Mast cell differentiation in the marrow is activated as part of the body response to parasites. We will review here the mast cell differentiation pathway and what is known of its major intrinsic and extrinsic control mechanisms. It will also be described that thrombopoietin, the ligand for the Mpl receptor, in addition to its pivotal rule in the control of thrombocytopoiesis and of hematopoietic stem/progenitor cell proliferation, exerts a regulatory function in mast cell differentiation. Some of the possible implications of this newly described biological activity of thrombopoietin will be discussed.

44. VIEW OF UMBILICAL MAST AND LAUNCH PAD FROM SOUTHWEST. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

44. VIEW OF UMBILICAL MAST AND LAUNCH PAD FROM SOUTHWEST. DOORS FOR THE UMBILICAL MAST TRENCH RAISED FOR MAINTENANCE POSITION OF 10 DEGREES. LAUNCHER IS RIGHT OF MAST; RAILS PARALLEL TO MAST. CONTROL PANELS LEFT TO RIGHT: ELECTRICAL PANEL, COMMUNICATIONS PANEL, AND MAST CONTROL PANEL. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Widespread immunological functions of mast cells: fact or fiction?

PubMed

Rodewald, Hans-Reimer; Feyerabend, Thorsten B

2012-07-27

Immunological functions of mast cells are currently considered to be much broader than the original role of mast cells in IgE-driven allergic disease. The spectrum of proposed mast cell functions includes areas as diverse as the regulation of innate and adaptive immune responses, protective immunity against viral, microbial, and parasitic pathogens, autoimmunity, tolerance to graft rejection, promotion of or protection from cancer, wound healing, angiogenesis, cardiovascular diseases, diabetes, obesity, and others. The vast majority of in vivo mast cell data have been based on mast cell-deficient Kit mutant mice. However, work in new mouse mutants with unperturbed Kit function, which have a surprisingly normal immune system, has failed to corroborate some key immunological aspects, formerly attributed to mast cells. Here, we consider the implications of these recent developments for the state of the field as well as for future work, aiming at deciphering the physiological functions of mast cells. Copyright © 2012 Elsevier Inc. All rights reserved.

Mast cells in the sheep, hedgehog and rat forebrain

PubMed Central

MICHALOUDI, HELEN C.; PAPADOPOULOS, GEORGIOS C.

1999-01-01

The study was designed to reveal the distribution of various mast cell types in the forebrain of the adult sheep, hedgehog and rat. Based on their histochemical and immunocytochemical characteristics, mast cells were categorised as (1) connective tissue-type mast cells, staining metachromatically purple with the toluidine blue method, or pale red with the Alcian blue/safranin method, (2) mucosal-type or immature mast cells staining blue with the Alcian blue/safranin method and (3) serotonin immunopositive mast cells. All 3 types of brain mast cells in all species studied were located in both white and grey matter, often associated with intraparenchymal blood vessels. Their distribution pattern exhibited interspecies differences, while their number varied considerably not only between species but also between individuals of each species. A distributional left-right asymmetry, with more cells present on the left side, was observed in all species studied but it was most prominent in the sheep brain. In the sheep, mast cells were abundantly distributed in forebrain areas, while in the hedgehog and the rat forebrain, mast cells were less widely distributed and were relatively or substantially fewer in number respectively. A limited number of brain mast cells, in all 3 species, but primarily in the rat, were found to react both immunocytochemically to 5-HT antibody and histochemically with Alcian blue/safranin staining. PMID:10634696

Loss of Histochemical Identity in Mast Cells Lacking Carboxypeptidase A

PubMed Central

Feyerabend, Thorsten B.; Hausser, Heinz; Tietz, Annette; Blum, Carmen; Hellman, Lars; Straus, Anita H.; Takahashi, Hélio K.; Morgan, Ellen S.; Dvorak, Ann M.; Fehling, Hans Jörg; Rodewald, Hans-Reimer

2005-01-01

Mast cell carboxypeptidase A (Mc-cpa) is a highly conserved secretory granule protease. The onset of expression in mast cell progenitors and lineage specificity suggest an important role for Mc-cpa in mast cells. To address the function of Mc-cpa, we generated Mc-cpa-null mice. Mc-cpa−/− mast cells lacked carboxypeptidase activity, revealing that Mc-cpa is a nonredundant enzyme. While Mc-cpa−/− peritoneal mast cells were ultrastructurally normal and synthesized normal amounts of heparin, they displayed striking histochemical and biochemical hallmarks of immature mast cells. Wild-type peritoneal mast cells had a mature phenotype characterized by differential histochemical staining with proteoglycan-reactive dyes (cells do not stain with alcian blue but stain with safranin and with berberine) and a high side scatter to forward scatter ratio by flow cytometry and were detergent resistant. In contrast, Mc-cpa−/− peritoneal mast cells, like immature bone marrow-derived cultured mast cells, stained with alcian blue normally or weakly and either did not stain with safranin and berberine or stained weakly, had a low side scatter to forward scatter ratio, and were detergent sensitive. This phenotype was partially ameliorated with age. Thus, histochemistry and flow cytometry, commonly used to measure mast cell maturation, deviated from morphology in Mc-cpa−/− mice. The Mc-cpa−/− mast cell phenotype was not associated with defects in degranulation in vitro or passive cutaneous anaphylaxis in vivo. Collectively, Mc-cpa plays a crucial role for the generation of phenotypically mature mast cells. PMID:15988029

Two centuries of masting data for European beech and Norway spruce across the European continent.

PubMed

Ascoli, Davide; Maringer, Janet; Hacket-Pain, Andy; Conedera, Marco; Drobyshev, Igor; Motta, Renzo; Cirolli, Mara; Kantorowicz, Władysław; Zang, Christian; Schueler, Silvio; Croisé, Luc; Piussi, Pietro; Berretti, Roberta; Palaghianu, Ciprian; Westergren, Marjana; Lageard, Jonathan G A; Burkart, Anton; Gehrig Bichsel, Regula; Thomas, Peter A; Beudert, Burkhard; Övergaard, Rolf; Vacchiano, Giorgio

2017-05-01

Tree masting is one of the most intensively studied ecological processes. It affects nutrient fluxes of trees, regeneration dynamics in forests, animal population densities, and ultimately influences ecosystem services. Despite a large volume of research focused on masting, its evolutionary ecology, spatial and temporal variability, and environmental drivers are still matter of debate. Understanding the proximate and ultimate causes of masting at broad spatial and temporal scales will enable us to predict tree reproductive strategies and their response to changing environment. Here we provide broad spatial (distribution range-wide) and temporal (century) masting data for the two main masting tree species in Europe, European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) H. Karst.). We collected masting data from a total of 359 sources through an extensive literature review and from unpublished surveys. The data set has a total of 1,747 series and 18,348 yearly observations from 28 countries and covering a time span of years 1677-2016 and 1791-2016 for beech and spruce, respectively. For each record, the following information is available: identification code; species; year of observation; proxy of masting (flower, pollen, fruit, seed, dendrochronological reconstructions); statistical data type (ordinal, continuous); data value; unit of measurement (only in case of continuous data); geographical location (country, Nomenclature of Units for Territorial Statistics NUTS-1 level, municipality, coordinates); first and last record year and related length; type of data source (field survey, peer reviewed scientific literature, gray literature, personal observation); source identification code; date when data were added to the database; comments. To provide a ready-to-use masting index we harmonized ordinal data into five classes. Furthermore, we computed an additional field where continuous series with length >4 yr where converted into a five classes

Carbonic anhydrase enzymes regulate mast cell–mediated inflammation

PubMed Central

Soteropoulos, Patricia

2016-01-01

Type 2 cytokine responses are necessary for the development of protective immunity to helminth parasites but also cause the inflammation associated with allergies and asthma. Recent studies have found that peripheral hematopoietic progenitor cells contribute to type 2 cytokine–mediated inflammation through their enhanced ability to develop into mast cells. In this study, we show that carbonic anhydrase (Car) enzymes are up-regulated in type 2–associated progenitor cells and demonstrate that Car enzyme inhibition is sufficient to prevent mouse mast cell responses and inflammation after Trichinella spiralis infection or the induction of food allergy–like disease. Further, we used CRISPR/Cas9 technology and illustrate that genetically editing Car1 is sufficient to selectively reduce mast cell development. Finally, we demonstrate that Car enzymes can be targeted to prevent human mast cell development. Collectively, these experiments identify a previously unrecognized role for Car enzymes in regulating mast cell lineage commitment and suggest that Car enzyme inhibitors may possess therapeutic potential that can be used to treat mast cell–mediated inflammation. PMID:27526715

Solar Array Mast Imagery Discussion for ISIW

NASA Technical Reports Server (NTRS)

Kilgo, Gary

2017-01-01

SAW Mast inspection background: In 2012, NASA's Flight Safety Office requested the Micro Meteoroid and Orbital Debris (MMOD) office determine the probability of damage to the Solar Array Wing (SAW) mast based on the exposure over the life time of the ISS program. As part of the risk mitigation of the potential MMOD strikes. ISS Program office along with the Image Science and Analysis Group (ISAG) began developing methods for imaging the structural components of the Mast.

New models for analyzing mast cell functions in vivo

PubMed Central

Reber, Laurent L.; Marichal, Thomas; Galli, Stephen J.

2013-01-01

In addition to their well-accepted role as critical effector cells in anaphylaxis and other acute IgE-mediated allergic reactions, mast cells have been implicated in a wide variety of process that contribute to disease or help to maintain health. While some of these roles were first suggested by analyses of mast cell products or functions in vitro, it is critical to determine whether, and under which circumstances, such potential roles actually can be performed by mast cells in vivo. This review discusses recent advances in the development and analysis of mouse models to investigate the roles of mast cells and mast cell-associated products during biological responses in vivo, and comments on some of the similarities and differences in the results obtained with these newer versus older models of mast cell deficiency. PMID:23127755

[Ultrastructural characteristics of mast cells and eosinophils in nasal inverted papilloma].

PubMed

Yokoshima, K; Ohnishi, M; Okuda, M; Okubo, K

1994-12-01

We previously found that an increased number of mast cells and eosinophils accumulated in nasal inverted papilloma and in the nasal mucosa of allergic subjects. Two subtypes of mast cells, i.e., mucosal mast cells and connective tissue mast cells are known to be present in the allergic nasal mucosa. Eosinophils in the allergic nasal mucosa are also heterogeneous. In addition, we demonstrated accumulation of formalin-sensitive mast cells at the tumor site of nasal inverted papilloma. The morphological characteristics and function of mast cells and eosinophils, however, have not yet been identified. The purpose of this study was to determine the ultrastructural characteristics of mast cells and eosinophils in relation to their function in tumor tissue. The results revealed two subtypes of mast cells in nasal inverted papilloma, one distributed mainly in the tumor site, the other mainly in the stromal site. These two subtypes of mast cells had different ultrastructural characteristics. In contrast to stromal mast cells, mast cells in the tumor site were characterized by a smaller cell diameter, fewer specific granules and a higher rate of degranulation. This suggested that they may have played some role in the pathogenesis of the tumor, however, their precise function is still unknown. In comparison with the mast cells in the allergic nasal mucosa, previously reported by Okuda et al, the mast cells in the tumor site were similar to those in the epithelial layer of the allergic nasal mucosa (MMCs), while mast cells in the stromal site resembled those in the lamina propria (CTMCs). There were no marked morphological differences between eosinophils in the tumor site and the stromal site.(ABSTRACT TRUNCATED AT 250 WORDS)

Masting promotes individual- and population-level reproduction by increasing pollination efficiency.

PubMed

Moreira, Xoaquín; Abdala-Roberts, Luis; Linhart, Yan B; Mooney, Kailen A

2014-04-01

Masting is a reproductive strategy defined as the intermittent and synchronized production of large seed crops by a plant population. The pollination efficiency hypothesis proposes that masting increases pollination success in plants. Despite its general appeal, no previous studies have used long-term data together with population- and individual-level analyses to assess pollination efficiency between mast and non-mast events. Here we rigorously tested the pollination efficiency hypothesis in ponderosa pine (Pinus ponderosa), a long-lived monoecious, wind-pollinated species, using a data set on 217 trees monitored annually for 20 years. Relative investment in male and female function by individual trees did not vary between mast and non-mast years. At both the population and individual level, the rate of production of mature female cones relative to male strobili production was higher in mast than non-mast years, consistent with the predicted benefit of reproductive synchrony on reproductive success. In addition, at the individual level we found a higher conversion of unfertilized female conelets into mature female cones during a mast year compared to a non-mast year. Collectively, parallel results at the population and individual tree level provide robust evidence for the ecological, and potentially also evolutionary, benefits of masting through increased pollination efficiency.

Mast cell hyperactivity underpins the development of oxygen-induced retinopathy

PubMed Central

Matsuda, Kenshiro; Okamoto, Noriko; Kondo, Masatoshi; Arkwright, Peter D.; Karasawa, Kaoru; Ishizaka, Saori; Yokota, Shinichi; Matsuda, Akira; Jung, Kyungsook; Oida, Kumiko; Jang, Hyosun; Noda, Eiichiro; Kakinuma, Ryota; Yasui, Koujirou; Kaku, Uiko; Mori, Yasuo; Onai, Nobuyuki; Ohteki, Toshiaki; Tanaka, Akane

2017-01-01

Mast cells are classically thought to play an important role in protection against helminth infections and in the induction of allergic diseases; however, recent studies indicate that these cells also contribute to neovascularization, which is critical for tissue remodeling, chronic inflammation, and carcinogenesis. Here, we demonstrate that mast cells are essential for sprouting angiogenesis in a murine model of oxygen-induced retinopathy (OIR). Although mouse strains lacking mast cells did not exhibit retinal neovascularization following hypoxia, these mice developed OIR following infusion of mast cells or after injection of mast cell tryptase (MCT). Relative hypoxia stimulated mast cell degranulation via transient receptor potential ankyrin 1. Subsequent surges in MCT stimulated retinal endothelial cells to produce monocyte chemotactic protein-1 (MCP1) and angiogenic factors, leading to sprouting angiogenesis. Mast cell stabilizers as well as specific tryptase and MCP1 inhibitors prevented the development of OIR in WT mice. Preterm infants with early retinopathy of prematurity had markedly higher plasma MCT levels than age-matched infants without disease, suggesting mast cells contribute to human disease. Together, these results suggest therapies that suppress mast cell activity should be further explored as a potential option for preventing eye diseases and subsequent blindness induced by neovascularization. PMID:28990934

Mast cells in rheumatoid arthritis: friends or foes?

PubMed

Rivellese, Felice; Nerviani, Alessandra; Rossi, Francesca Wanda; Marone, Gianni; Matucci-Cerinic, Marco; de Paulis, Amato; Pitzalis, Costantino

2017-06-01

Mast cells are tissue-resident cells of the innate immunity, implicated in the pathogenesis of many autoimmune diseases, including rheumatoid arthritis (RA). They are present in synovia and their activation has been linked to the potentiation of inflammation in the course of RA. However, recent investigations questioned the role of mast cells in arthritis. In particular, animal models generated conflicting results, so that many of their pro-inflammatory, i.e. pro-arthritogenic functions, even though supported by robust experimental evidence, have been labelled as redundant. At the same time, a growing body of evidence suggests that mast cells can act as tunable immunomodulatory cells. These characteristics, not yet fully understood in the context of RA, could partially explain the inconsistent results obtained with experimental models, which do not account for the pro- and anti-inflammatory functions exerted in more chronic heterogeneous conditions such as RA. Here we present an overview of the current knowledge on mast cell involvement in RA, including the intriguing hypothesis of mast cells acting as subtle immunomodulatory cells and the emerging concept of synovial mast cells as potential biomarkers for patient stratification. Copyright © 2017 Elsevier B.V. All rights reserved.

Mast cells: potential positive and negative roles in tumor biology.

PubMed

Marichal, Thomas; Tsai, Mindy; Galli, Stephen J

2013-11-01

Mast cells are immune cells that reside in virtually all vascularized tissues. Upon activation by diverse mechanisms, mast cells can secrete a broad array of biologically active products that either are stored in the cytoplasmic granules of the cells (e.g., histamine, heparin, various proteases) or are produced de novo upon cell stimulation (e.g., prostaglandins, leukotrienes, cytokines, chemokines, and growth factors). Mast cells are best known for their effector functions during anaphylaxis and acute IgE-associated allergic reactions, but they also have been implicated in a wide variety of processes that maintain health or contribute to disease. There has been particular interest in the possible roles of mast cells in tumor biology. In vitro studies have shown that mast cells have the potential to influence many aspects of tumor biology, including tumor development, tumor-induced angiogenesis, and tissue remodeling, and the shaping of adaptive immune responses to tumors. Yet, the actual contributions of mast cells to tumor biology in vivo remain controversial. Here, we review some basic features of mast cell biology with a special emphasis on those relevant to their potential roles in tumors. We discuss how using in vivo tumor models in combination with models in which mast cell function can be modulated has implicated mast cells in the regulation of host responses to tumors. Finally, we summarize data from studies of human tumors that suggest either beneficial or detrimental roles for mast cells in tumors. ©2013 AACR.

Changes in numbers and types of mast cell colony-forming cells in the peritoneal cavity of mice after injection of distilled water: evidence that mast cells suppress differentiation of bone marrow-derived precursors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kanakura, Y.; Kuriu, A.; Waki, N.

Two different types of cells in the peritoneal cavity of mice produce mast cell colonies in methylcellulose. Large mast cell colonies are produced by bone marrow-derived precursors resembling lymphoid cells by light microscopy (L-CFU-Mast), whereas medium and small mast cell colonies are produced by morphologically identifiable mast cells (M-CFU-Mast and S-CFU-Mast, respectively). In the present study we eradicated peritoneal mast cells by intraperitoneal (IP) injection of distilled water. The regeneration process was investigated to clarify the relationship between L-CFU-Mast, M-CFU-Mast, and S-CFU-Mast. After injection of distilled water, M-CFU-Mast and S-CFU-Mast disappeared, but L-CFU-Mast increased, and then M-CFU-Mast and S-CFU-Mast appeared,more » suggesting the presence of a hierarchic relationship. When purified peritoneal mast cells were injected two days after the water injection, the L-CFU-Mast did not increase. In the peritoneal cavity of WBB6F1-+/+ mice that had been lethally irradiated and rescued by bone marrow cells of C57BL/6-bgJ/bgJ (beige, Chediak-Higashi syndrome) mice, L-CFU-Mast were of bgJ/bgJ type, but M-CFU-Mast and S-CFU-Mast were of +/+ type. The injection of distilled water to the radiation chimeras resulted in the development of bgJ/bgJ-type M-CFU-Mast and then S-CFU-Mast. The presence of mast cells appeared to suppress the recruitment of L-CFU-Mast from the bloodstream and to inhibit the differentiation of L-CFU-Mast to M-CFU-Mast.« less

Basic science for the clinician 53: mast cells.

PubMed

Sigal, Leonard H

2011-10-01

Mast cells stand at the interface between the innate immune system and the acquired (adaptive) immune response, serving as sentinels detecting invaders and directing a concerted and coordinated response. Mast cells reside immediately under body surfaces and within lymph nodes, near blood vessels and nerves, perfectly situated to for early detection and defense. They secrete a wide array of prostanoids, cytokines, chemokines, and other proteins mediators and modifiers of a variety of immune and inflammatory functions and bear surface markers suggesting broad functions, including as antigen-presenting cells. Although usually not given their due in medical school lectures, there is great likelihood that mast cells will be implicated in the pathogenesis of rheumatoid arthritis, scleroderma, multiple sclerosis, and perhaps cancer. Thus, better insights into mast cell functions and mast cell-derived effector molecules should command our attention as we move forward in better understanding disease immunopathogenesis and directed intelligent therapeutics development.

Curiosity on Tilt Table with Mast Up

NASA Image and Video Library

2011-03-25

The Mast Camera Mastcam on NASA Mars rover Curiosity has two rectangular eyes near the top of the rover remote sensing mast. This image shows Curiosity on a tilt table NASA Jet Propulsion Laboratory, Pasadena, California.

Mast cells in atherosclerotic cardiovascular disease - Activators and actions.

PubMed

Kovanen, Petri T; Bot, Ilze

2017-12-05

Mast cells are potent actors involved in inflammatory reactions in various tissues, including both in the intimal and the adventitial layers of atherosclerotic arteries. In the arterial intima, the site of atherogenesis, mast cells are activated to degranulate, and thereby triggered to release an abundance of preformed inflammatory mediators, notably histamine, heparin, neutral proteases and cytokines stored in their cytoplasmic secretory granules. Depending on the stimulus, mast cell activation may also launch prolonged synthesis and secretion of single bioactive molecules, such as cytokines and derivatives of arachidonic acid. The mast cell-derived mediators may impede the functions of different types of cells present in atherosclerotic lesions, and also compromise the structural and functional integrity of the intimal extracellular matrix. In the adventitial layer of atherosclerotic coronary arteries, mast cells locate next to peptidergic sensory nerve fibers, which, by releasing neuropeptides may activate mast cells to release vasoactive compounds capable of triggering local vasoconstriction. The concerted actions of arterial mast cells have the potential to contribute to the initiation and progression of atherosclerosis, and ultimately to destabilization and rupture of an advanced atherosclerotic plaque with ensuing atherothrombotic complications. Copyright © 2017 Elsevier B.V. All rights reserved.

Mast Cell Interactions and Crosstalk in Regulating Allergic Inflammation.

PubMed

Velez, Tania E; Bryce, Paul J; Hulse, Kathryn E

2018-04-17

This review summarizes recent findings on mast cell biology with a focus on IgE-independent roles of mast cells in regulating allergic responses. Recent studies have described novel mast cell-derived molecules, both secreted and membrane-bound, that facilitate cross-talk with a variety of immune effector cells to mediate type 2 inflammatory responses. Mast cells are complex and dynamic cells that are persistent in allergy and are capable of providing signals that lead to the initiation and persistence of allergic mechanisms.

Mast cells and exosomes in hyperoxia-induced neonatal lung disease.

PubMed

Veerappan, A; Thompson, M; Savage, A R; Silverman, M L; Chan, W S; Sung, B; Summers, B; Montelione, K C; Benedict, P; Groh, B; Vicencio, A G; Peinado, H; Worgall, S; Silver, R B

2016-06-01

Chronic lung disease of prematurity (CLD) is a frequent sequela of premature birth and oxygen toxicity is a major associated risk factor. Impaired alveolarization, scarring, and inflammation are hallmarks of CLD. Mast cell hyperplasia is a feature of CLD but the role of mast cells in its pathogenesis is unknown. We hypothesized that mast cell hyperplasia is a consequence of neonatal hyperoxia and contributes to CLD. Additionally, mast cell products may have diagnostic and prognostic value in preterm infants predisposed to CLD. To model CLD, neonatal wild-type and mast cell-deficient mice were placed in an O2 chamber delivering hyperoxic gas mixture [inspired O2 fraction (FiO2 ) of 0.8] (HO) for 2 wk and then returned to room air (RA) for an additional 3 wk. Age-matched controls were kept in RA (FiO2 of 0.21). Lungs from HO mice had increased numbers of mast cells, alveolar simplification and enlargement, and increased lung compliance. Mast cell deficiency proved protective by preserving air space integrity and lung compliance. The mast cell mediators β-hexosaminidase (β-hex), histamine, and elastase increased in the bronchoalveolar lavage fluid of HO wild-type mice. Tracheal aspirate fluids (TAs) from oxygenated and mechanically ventilated preterm infants were analyzed for mast cell products. In TAs from infants with confirmed cases of CLD, β-hex was elevated over time and correlated with FiO2 Mast cell exosomes were also present in the TAs. Collectively, these data show that mast cells play a significant role in hyperoxia-induced lung injury and their products could serve as potential biomarkers in evolving CLD. Copyright © 2016 the American Physiological Society.

Introduction to the MAST Program. MAS-100. Waste Isolation Division (WID). Management and Supervisor Training (MAST) Program.

ERIC Educational Resources Information Center

Westinghouse Electric Corp., Carlsbad, NM.

This module is part of a set of management and supervisor training (MAST) materials developed by the Department of Energy for the Waste Isolation Division. Its stated purpose is to provide participants with knowledge and skills necessary to take full advantage of the MAST learning experience. The module contains program guidelines, sample…

Mechanism of mast cell adhesion to human tenocytes in vitro.

PubMed

Behzad, Hayedeh; Tsai, Shu-Huei; Nassab, Paulina; Mousavizadeh, Rouhollah; McCormack, Robert G; Scott, Alex

2015-01-01

Mast cells and fibroblasts are two key players involved in many fibrotic and degenerative disorders. In the present study we examined the nature of binding interactions between human mast cells and tendon fibroblasts (tenocytes). In the mast cell-fibroblast co-culture model, mast cells were shown to spontaneously bind to tenocytes, in a process that was partially mediated by α5β1 integrin receptors. The same receptors on mast cells significantly mediated binding of these cells to tissue culture plates in the presence of tenocyte-conditioned media; the tenocyte-derived fibronectin in the media was shown to also play a major role in these binding activities. Upon binding to tenocytes or tissue culture plates, mast cells acquired an elongated phenotype, which was dependent on α5β1 integrin and tenocyte fibronectin. Additionally, tenocyte-derived fibronectin significantly enhanced mRNA expression of the adhesion molecule, THY1, by mast cells. Our data suggests that α5β1 integrin mediates binding of mast cells to human tenocyte and to tenocyte-derived ECM proteins, in particular fibronectin. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Vaccine adjuvants: Tailor-made mast-cell granules

NASA Astrophysics Data System (ADS)

Gunzer, Matthias

2012-03-01

Mast cells induce protective immune responses through secretion of stimulatory granules. Microparticles modelled after mast-cell granules are now shown to replicate and enhance the functions of their natural counterparts and to direct the character of the resulting immunity.

Tumor microvessel density–associated mast cells in canine nodal lymphoma

PubMed Central

Mann, Elizabeth; Whittington, Lisa

2014-01-01

Objective: Mast cells are associated in angiogenesis in various human and animal neoplasms. However, association of mast cells with tumor microvessel density in canine lymphoma was not previously documented. The objective of the study is to determine if mast cells are increased in canine nodal lymphomas and to evaluate their correlation with tumor microvessel density and grading of lymphomas. Methods: Nodal lymphomas from 33 dogs were studied and compared with nonneoplastic lymph nodes from 6 dogs as control. Mast cell count was made on Toluidine blue stained sections. Immunohistochemistry using antibody against Factor VIII was employed to visualize and determine microvessel density. Results: The mast cell count in lymphoma (2.95 ± 2.4) was significantly higher (p < 0.05) than that in the control (0.83 ± 0.3) and was positively correlated with tumor microvessel density (r = 0.44, p = 0.009). Significant difference was not observed in mast cell count and tumor microvessel density among different gradings of lymphomas. Conclusions: Mast cells are associated with tumor microvessel density in canine nodal lymphoma with no significant difference among gradings of lymphomas. Mast cells may play an important role in development of canine nodal lymphomas. Further detailed investigation on the role of mast cells as important part of tumor microenvironment in canine nodal lymphomas is recommended. PMID:26770752

The impact of mast cells on cardiovascular diseases.

PubMed

Kritikou, Eva; Kuiper, Johan; Kovanen, Petri T; Bot, Ilze

2016-05-05

Mast cells comprise an innate immune cell population, which accumulates in tissues proximal to the outside environment and, upon activation, augments the progression of immunological reactions through the release and diffusion of either pre-formed or newly generated mediators. The released products of mast cells include histamine, proteases, as well as a variety of cytokines, chemokines and growth factors, which act on the surrounding microenvironment thereby shaping the immune responses triggered in various diseased states. Mast cells have also been detected in the arterial wall and are implicated in the onset and progression of numerous cardiovascular diseases. Notably, modulation of distinct mast cell actions using genetic and pharmacological approaches highlights the crucial role of this cell type in cardiovascular syndromes. The acquired evidence renders mast cells and their mediators as potential prognostic markers and therapeutic targets in a broad spectrum of pathophysiological conditions related to cardiovascular diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

Scalability Assessments for the Malicious Activity Simulation Tool (MAST)

DTIC Science & Technology

2012-09-01

the scalability characteristics of MAST. Specifically, we show that an exponential increase in clients using the MAST software does not impact...an exponential increase in clients using the MAST software does not impact network and system resources significantly. Additionally, we...31 1. Hardware .....................................31 2. Software .....................................32 3. Common PC

KSC01PD1762

NASA Image and Video Library

2001-12-03

KENNEDY SPACE CENTER, Fla. -- Rain on the ground around Space Shuttle Endeavour on Launch Pad 39B reflects the many lights illluminating the Rotating Service Structure (at left), Fixed Service Structure and Shuttle. Twin solid rocket boosters flank the orange external tank behind Endeavour. Above the external tank is the Gaseous Oxygen Vent Arm that vents gaseous oxygen vapors away from the Shuttle. The vent hood assembly at the end is often referred to as the "beanie cap." Stretching from the FSS to the crew hatch on the side of Endeavour is the Orbiter Access Arm with its environmentally controlled White Room at the end, through which the crew enters the vehicle. The Shuttle sits on the Mobile Launcher Platform with the two service tail masts on either side of the main engines. The tail masts support the fluid, gas and electrical requirements of the orbiter's liquid oxygen and liquid hydrogen aft T-0 umbilicals. Each tail mast is 31 feet (9.4 meters) high, 15 feet (4.6 meters) long and 9 feet (3.1 meters) wide. Endeavour is scheduled to launch on mission STS-108 Dec. 4 at 5:45 p.m. EST. On this 12th flight to the International Space Station, known as a Utilization Flight, Endeavour will carry a crew of four plus the Expedition 4 crew, who will replace Expedition 3 aboard the ISS. The payload includes the Multi-Purpose Logistics Module Raffaello, filled with supplies, equipment and experiments

Ablation of human skin mast cells in situ by lysosomotropic agents.

PubMed

Hagforsen, Eva; Paivandy, Aida; Lampinen, Maria; Weström, Simone; Calounova, Gabriela; Melo, Fabio R; Rollman, Ola; Pejler, Gunnar

2015-07-01

Mast cells are known to have a detrimental impact on numerous types of inflammatory skin diseases such as contact dermatitis, atopic eczema and cutaneous mastocytosis. Regimens that dampen skin mast cell-mediated activities can thus offer an attractive therapeutic option under such circumstances. As mast cells are known to secrete a large array of potentially pathogenic compounds, both from preformed stores in secretory lysosomes (granules) and after de novo synthesis, mere inhibition of degranulation or interference with individual mast cell mediators may not be sufficient to provide an effective blockade of harmful mast cell activities. An alternative strategy may therefore be to locally reduce skin mast cell numbers. Here, we explored the possibility of using lysosomotropic agents for this purpose, appreciating the fact that mast cell granules contain bioactive compounds prone to trigger apoptosis if released into the cytosolic compartment. Based on this principle, we show that incubation of human skin punch biopsies with the lysosomotropic agents siramesine or Leu-Leu methyl ester preferably ablated the mast cell population, without causing any gross adverse effects on the skin morphology. Subsequent analysis revealed that mast cells treated with lysosomotropic agents predominantly underwent apoptotic rather than necrotic cell death. In summary, this study raises the possibility of using lysosomotropic agents as a novel approach to targeting deleterious mast cell populations in cutaneous mastocytosis and other skin disorders negatively influenced by mast cells. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Approaches for Analyzing the Roles of Mast Cells and Their Proteases In Vivo

PubMed Central

Galli, Stephen J.; Tsai, Mindy; Marichal, Thomas; Tchougounova, Elena; Reber, Laurent L.; Pejler, Gunnar

2016-01-01

The roles of mast cells in health and disease remain incompletely understood. While the evidence that mast cells are critical effector cells in IgE-dependent anaphylaxis and other acute IgE-mediated allergic reactions seems unassailable, studies employing various mice deficient in mast cells or mast cell-associated proteases have yielded divergent conclusions about the roles of mast cells or their proteases in certain other immunological responses. Such “controversial” results call into question the relative utility of various older versus newer approaches to ascertain the roles of mast cells and mast cell proteases in vivo. This review discusses how both older and more recent mouse models have been used to investigate the functions of mast cells and their proteases in health and disease. We particularly focus on settings in which divergent conclusions about the importance of mast cells and their proteases have been supported by studies that employed different models of mast cell or mast cell protease deficiency. We think that two major conclusions can be drawn from such findings: (1) no matter which models of mast cell or mast cell protease deficiency one employs, the conclusions drawn from the experiments always should take into account the potential limitations of the models (particularly abnormalities affecting cell types other than mast cells) and (2) even when analyzing a biological response using a single model of mast cell or mast cell protease deficiency, details of experimental design are critical in efforts to define those conditions under which important contributions of mast cells or their proteases can be identified. PMID:25727288

Mast cell-neural interactions contribute to pain and itch.

PubMed

Gupta, Kalpna; Harvima, Ilkka T

2018-03-01

Mast cells are best recognized for their role in allergy and anaphylaxis, but increasing evidence supports their role in neurogenic inflammation leading to pain and itch. Mast cells act as a "power house" by releasing algogenic and pruritogenic mediators, which initiate a reciprocal communication with specific nociceptors on sensory nerve fibers. Consequently, nerve fibers release inflammatory and vasoactive neuropeptides, which in turn activate mast cells in a feedback mechanism, thus promoting a vicious cycle of mast cell and nociceptor activation leading to neurogenic inflammation and pain/pruritus. Mechanisms underlying mast cell differentiation, activation, and intercellular interactions with inflammatory, vascular, and neural systems are deeply influenced by their microenvironment, imparting enormous heterogeneity and complexity in understanding their contribution to pain and pruritus. Neurogenic inflammation is central to both pain and pruritus, but specific mediators released by mast cells to promote this process may vary depending upon their location, stimuli, underlying pathology, gender, and species. Therefore, in this review, we present the contribution of mast cells in pathological conditions, including distressing pruritus exacerbated by psychologic stress and experienced by the majority of patients with psoriasis and atopic dermatitis and in different pain syndromes due to mastocytosis, sickle cell disease, and cancer. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Neuropeptides activate human mast cell degranulation and chemokine production

PubMed Central

Kulka, Marianna; Sheen, Cecilia H; Tancowny, Brian P; Grammer, Leslie C; Schleimer, Robert P

2008-01-01

During neuronal-induced inflammation, mast cells may respond to stimuli such as neuropeptides in an FcεRI-independent manner. In this study, we characterized human mast cell responses to substance P (SP), nerve growth factor (NGF), calcitonin gene-related peptide (CGRP) and vasoactive intestinal polypeptide (VIP) and compared these responses to human mast cell responses to immunoglobulin E (IgE)/anti-IgE and compound 48/80. Primary cultured mast cells, generated from CD34+ progenitors in the presence of stem cell factor and interleukin-6 (IL-6), and human cultured mast cells (LAD2) were stimulated with these and other stimuli (gastrin, concanavalin A, radiocontrast media, and mannitol) and their degranulation and chemokine production was assessed. VIP and SP stimulated primary human mast cells and LAD cells to degranulate; gastrin, concanavalin A, radiocontrast media, mannitol, CGRP and NGF did not activate degranulation. While anti-IgE stimulation did not induce significant production of chemokines, stimulation with VIP, SP or compound 48/80 potently induced production of monocyte chemoattractant protein-1, inducible protein-10, monokine induced by interferon-γ (MIG), RANTES (regulated on activation, normal, T-cell expressed, and secreted) and IL-8. VIP, SP and compound 48/80 also activated release of tumour necrosis factor, IL-3 and granulocyte–macrophage colony-stimulating factor, but not IL-4, interferon-γ or eotaxin. Human mast cells expressed surface neurokinin 1 receptor (NK1R), NK2R, NK3R and VIP receptor type 2 (VPAC2) but not VPAC1 and activation of human mast cells by IgE/anti-IgE up-regulated expression of VPAC2, NK2R, and NK3R. These studies demonstrate the pattern of receptor expression and activation of mast cell by a host of G-protein coupled receptor ligands and suggest that SP and VIP activate a unique signalling pathway in human mast cells. These results are likely to have direct relevance to neuronally induced inflammatory diseases. PMID

Sources and methods to reconstruct past masting patterns in European oak species.

PubMed

Szabó, Péter

2012-01-01

The irregular occurrence of good seed years in forest trees is known in many parts of the world. Mast year frequency in the past few decades can be examined through field observational studies; however, masting patterns in the more distant past are equally important in gaining a better understanding of long-term forest ecology. Past masting patterns can be studied through the examination of historical written sources. These pose considerable challenges, because data in them were usually not recorded with the aim of providing information about masting. Several studies examined masting in the deeper past, however, authors hardly ever considered the methodological implications of using and combining various source types. This paper provides a critical overview of the types of archival written that are available for the reconstruction of past masting patterns for European oak species and proposes a method to unify and evaluate different types of data. Available sources cover approximately eight centuries and can be put into two basic categories: direct observations on the amount of acorns and references to sums of money received in exchange for access to acorns. Because archival sources are highly different in origin and quality, the optimal solution for creating databases for past masting data is a three-point scale: zero mast, moderate mast, good mast. When larger amounts of data are available in a unified three-point-scale database, they can be used to test hypotheses about past masting frequencies, the driving forces of masting or regional masting patterns.

Tissue-dependent differences in the asynchronous appearance of mast cells in normal mice and in congenic mast cell-deficient mice after infusion of normal bone marrow cells

PubMed Central

DU, T; FRIEND, D S; AUSTEN, K F; KATZ, H R

1996-01-01

The time courses of the appearance of tissue mast cells in six sites were compared in normal WBB6F1-+/+ mice (+/+) and in congenic mast cell-deficient WBB6F1-W/Wv mice (W/Wv) that received an intravenous infusion of bone marrow cells from +/+mice (BM→W/Wv). As assessed by morphometric analysis of Carnoy's solution-fixed, methylene blue-stained tissue sections, the density of mast cells in the stomach mucosa, stomach submucosa, and spleen of +/+ mice reached maximal levels by 8 weeks of age, whereas the density of mast cells in the skin, extraparenchymal airway walls, and lung parenchyma did not reach maximal levels until 18 weeks of age. When 8-week-old W/Wv mice were infused with 2×107 bone marrow cells from +/+ mice, mast cells appeared in the stomach mucosa and submucosa after 2.5 weeks, in the spleen and extraparenchymal airway walls after 5 weeks, and in the lung parenchyma after 10 weeks. Twenty weeks after bone marrow infusion, the mast cell densities in the spleen, stomach mucosa, and stomach submucosa were seven-, 13-, and five-fold greater, respectively, than those in age-matched +/+ mice, but were eight-, two-, and five-fold lower in the skin, extraparenchymal airway walls, and lung parenchyma, respectively. Thus, those tissues that in +/+ mice reached maximal mast cell densities earlier exhibited abnormally high mast cell densities in BM→W/Wv mice, and those that reached maximal mast cell densities later in +/+ mice had abnormally low mast cell densities in BM→W/Wv mice. Immunological and inflammatory responses are often compared in W/Wv and BM→W/Wv mice to assess mast cell dependency. Our results indicate that the capacity to restore a mast cell-dependent response in a particular tissue of the latter mice may relate to the local mast cell density and whether the immunological challenge activates mast cells only in that tissue or systematically with attendant widespread release of proinflammatory mediators. PMID:8565318

Quantification and localization of mast cells in periapical lesions.

PubMed

Mahita, V N; Manjunatha, B S; Shah, R; Astekar, M; Purohit, S; Kovvuru, S

2015-01-01

Periapical lesions occur in response to chronic irritation in periapical tissue, generally resulting from an infected root canal. Specific etiological agents of induction, participating cell population and growth factors associated with maintenance and resolution of periapical lesions are incompletely understood. Among the cells found in periapical lesions, mast cells have been implicated in the inflammatory mechanism. Quantifications and the possible role played by mast cells in the periapical granuloma and radicular cyst. Hence, this study is to emphasize the presence (localization) and quantification of mast cells in periapical granuloma and radicular cyst. A total of 30 cases and out of which 15 of periapical granuloma and 15 radicular cyst, each along with the case details from the previously diagnosed cases in the department of oral pathology were selected for the study. The gender distribution showed male 8 (53.3%) and females 7 (46.7%) in periapical granuloma cases and male 10 (66.7%) and females 5 (33.3%) in radicular cyst cases. The statistical analysis used was unpaired t-test. Mean mast cell count in periapical granuloma subepithelial and deeper connective tissue, was 12.40 (0.99%) and 7.13 (0.83%), respectively. The mean mast cell counts in subepithelial and deeper connective tissue of radicular cyst were 17.64 (1.59%) and 12.06 (1.33%) respectively, which was statistically significant. No statistical significant difference was noted among males and females. Mast cells were more in number in radicular cyst. Based on the concept that mast cells play a critical role in the induction of inflammation, it is logical to use therapeutic agents to alter mast cell function and secretion, to thwart inflammation at its earliest phases. These findings may suggest the possible role of mast cells in the pathogenesis of periapical lesions.

Quantification and Localization of Mast Cells in Periapical Lesions

PubMed Central

Mahita, VN; Manjunatha, BS; Shah, R; Astekar, M; Purohit, S; Kovvuru, S

2015-01-01

Background: Periapical lesions occur in response to chronic irritation in periapical tissue, generally resulting from an infected root canal. Specific etiological agents of induction, participating cell population and growth factors associated with maintenance and resolution of periapical lesions are incompletely understood. Among the cells found in periapical lesions, mast cells have been implicated in the inflammatory mechanism. Aim: Quantifications and the possible role played by mast cells in the periapical granuloma and radicular cyst. Hence, this study is to emphasize the presence (localization) and quantification of mast cells in periapical granuloma and radicular cyst. Materials and Methods: A total of 30 cases and out of which 15 of periapical granuloma and 15 radicular cyst, each along with the case details from the previously diagnosed cases in the department of oral pathology were selected for the study. The gender distribution showed male 8 (53.3%) and females 7 (46.7%) in periapical granuloma cases and male 10 (66.7%) and females 5 (33.3%) in radicular cyst cases. The statistical analysis used was unpaired t-test. Results: Mean mast cell count in periapical granuloma subepithelial and deeper connective tissue, was 12.40 (0.99%) and 7.13 (0.83%), respectively. The mean mast cell counts in subepithelial and deeper connective tissue of radicular cyst were 17.64 (1.59%) and 12.06 (1.33%) respectively, which was statistically significant. No statistical significant difference was noted among males and females. Conclusion: Mast cells were more in number in radicular cyst. Based on the concept that mast cells play a critical role in the induction of inflammation, it is logical to use therapeutic agents to alter mast cell function and secretion, to thwart inflammation at its earliest phases. These findings may suggest the possible role of mast cells in the pathogenesis of periapical lesions. PMID:25861530

Thrombomodulin inhibits the activation of eosinophils and mast cells.

PubMed

Roeen, Ziaurahman; Toda, Masaaki; D'Alessandro-Gabazza, Corina N; Onishi, Masahiro; Kobayashi, Tetsu; Yasuma, Taro; Urawa, Masahito; Taguchi, Osamu; Gabazza, Esteban C

2015-01-01

Eosinophils and mast cells play critical roles in the pathogenesis of bronchial asthma. Activation of both cells leads to the release of pro-inflammatory mediators in the airway of asthmatic patients. Recently, we have shown that inhaled thrombomodulin inhibits allergic bronchial asthma in a mouse model. In the present study, we hypothesize that thrombomodulin can inhibit the activation of eosinophils and mast cells. The effect of thrombomodulin on the activation and release of inflammatory mediators from eosinophils and mast cells was evaluated. Thrombomodulin inhibited the eotaxin-induced chemotaxis, upregulation of CD11b and degranulation of eosinophils. Treatment with thrombomodulin also significantly suppressed the degranulation and synthesis of inflammatory cytokines and chemokines in eosinophils and mast cells. Mice treated with a low-dose of inhaled thrombomodulin have decreased number of eosinophils and activated mast cells and Th2 cytokines in the lungs compared to untreated mice. The results of this study suggest that thrombomodulin may modulate allergic responses by inhibiting the activation of both eosinophils and mast cells. Copyright © 2014 Elsevier Inc. All rights reserved.

Contribution of engineered nanomaterials physicochemical properties to mast cell degranulation

NASA Astrophysics Data System (ADS)

Johnson, Monica M.; Mendoza, Ryan; Raghavendra, Achyut J.; Podila, Ramakrishna; Brown, Jared M.

2017-03-01

The rapid development of engineered nanomaterials (ENMs) has grown dramatically in the last decade, with increased use in consumer products, industrial materials, and nanomedicines. However, due to increased manufacturing, there is concern that human and environmental exposures may lead to adverse immune outcomes. Mast cells, central to the innate immune response, are one of the earliest sensors of environmental insult and have been shown to play a role in ENM-mediated immune responses. Our laboratory previously determined that mast cells are activated via a non-FcɛRI mediated response following silver nanoparticle (Ag NP) exposure, which was dependent upon key physicochemical properties. Using bone marrow-derived mast cells (BMMCs), we tested the hypothesis that ENM physicochemical properties influence mast cell degranulation. Exposure to 13 physicochemically distinct ENMs caused a range of mast degranulation responses, with smaller sized Ag NPs (5 nm and 20 nm) causing the most dramatic response. Mast cell responses were dependent on ENMs physicochemical properties such as size, apparent surface area, and zeta potential. Surprisingly, minimal ENM cellular association by mast cells was not correlated with mast cell degranulation. This study suggests that a subset of ENMs may elicit an allergic response and contribute to the exacerbation of allergic diseases.

Mast cells contribute to scar formation during fetal wound healing.

PubMed

Wulff, Brian C; Parent, Allison E; Meleski, Melissa A; DiPietro, Luisa A; Schrementi, Megan E; Wilgus, Traci A

2012-02-01

Scar formation is a potentially detrimental process of tissue restoration in adults, affecting organ form and function. During fetal development, cutaneous wounds heal without inflammation or scarring at early stages of development; however, they begin to heal with significant inflammation and scarring as the skin becomes more mature. One possible cell type that could regulate the change from scarless to fibrotic healing is the mast cell. We show here that dermal mast cells in scarless wounds generated at embryonic day 15 (E15) are fewer in number, less mature, and do not degranulate in response to wounding as effectively as mast cells of fibrotic wounds made at embryonic day 18 (E18). Differences were also observed between cultured mast cells from E15 and E18 skin, with regard to degranulation and preformed cytokine levels. Injection of mast cell lysates into E15 wounds disrupted scarless healing, suggesting that mast cells interfere with scarless repair. Finally, wounds produced at E18, which normally heal with a scar, healed with significantly smaller scars in mast cell-deficient Kit(W/W-v) mice compared with Kit(+/+) littermates. Together, these data suggest that mast cells enhance scar formation, and that these cells may mediate the transition from scarless to fibrotic healing during fetal development.

Meningeal mast cell-T cell crosstalk regulates T cell encephalitogenicity.

PubMed

Russi, Abigail E; Walker-Caulfield, Margaret E; Guo, Yong; Lucchinetti, Claudia F; Brown, Melissa A

2016-09-01

GM-CSF is a cytokine produced by T helper (Th) cells that plays an essential role in orchestrating neuroinflammation in experimental autoimmune encephalomyelitis, a rodent model of multiple sclerosis. Yet where and how Th cells acquire GM-CSF expression is unknown. In this study we identify mast cells in the meninges, tripartite tissues surrounding the brain and spinal cord, as important contributors to antigen-specific Th cell accumulation and GM-CSF expression. In the absence of mast cells, Th cells do not accumulate in the meninges nor produce GM-CSF. Mast cell-T cell co-culture experiments and selective mast cell reconstitution of the meninges of mast cell-deficient mice reveal that resident meningeal mast cells are an early source of caspase-1-dependent IL-1β that licenses Th cells to produce GM-CSF and become encephalitogenic. We also provide evidence of mast cell-T cell co-localization in the meninges and CNS of recently diagnosed acute MS patients indicating similar interactions may occur in human demyelinating disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

Gypsy moth effects on mast production

Treesearch

Kurt W. Gottschalk

1990-01-01

Gypsy moth outbreaks can have drastic effects on many forest resources and uses. Because the gypsy moth prefers oak foliage, oak stands are the most susceptible to defoliation and resultant damage. The value of oak mast for many wildlife species is high. The high carbohydrate content of acorns provides the energy necessary for winter survival. Loss of mast crops due to...

Differential eosinophil and mast cell regulation: Mast cell viability and accumulation in inflammatory tissue are independent of proton-sensing receptor GPR65

PubMed Central

Zhu, Xiang; Mose, Eucabeth; Hogan, Simon P.

2014-01-01

Extracellular acidification has been observed in allergic inflammatory diseases. Recently, we demonstrated that the proton-sensing receptor G protein-coupled receptor 65 (GPR65) regulates eosinophil survival in an acidic environment in vitro and eosinophil accumulation in an allergic lung inflammation model. For mast cells, another inflammatory cell type critical for allergic responses, it remains unknown whether GPR65 is expressed and/or regulates mast cell viability. Thus, in the present study, we employed in vitro experiments and an intestinal anaphylaxis model in which both mastocytosis and eosinophilia can be observed, particularly in the gastrointestinal tract, to enable us to directly compare the effect of GPR65 expression on these two cell types. We identified GPR65 expression on mast cells; however, unlike eosinophil viability, mast cell viability in vitro is not affected by acidification or GPR65 expression. Mechanistically, we determined that mast cells do not respond to extracellular acidification with increased cAMP levels. Furthermore, in the intestinal anaphylaxis model, we observed a significant reduction of eosinophils (59.1 ± 9.2% decrease) in the jejunum of allergen-challenged GPR65-deficient mice compared with allergen-challenged wild-type mice, despite the degree of antigen sensitization and the expression levels of Th2 cytokines (Il4, Il13) and eosinophil chemokines (Ccl11, Ccl24) in the jejunum being comparable. In contrast, the accumulation of mast cells in allergen-challenged mice was not affected by GPR65 deficiency. In conclusion, our study demonstrates differential regulation of eosinophils and mast cells in inflammatory tissue, with mast cell viability and accumulation being independent of GPR65. PMID:24742990

KSC01pp0443

NASA Image and Video Library

2001-03-08

KENNEDY SPACE CENTER, Fla. -- Space Shuttle Discovery shines on Launch Pad 39B after rollback of the Rotating Service Structure. Situated above the external tank is the Gaseous Oxygen Vent Arm with the “beanie cap,” a vent hood. Extended out from the Fixed Service Structure (left) to the orbiter is the orbiter access arm with an environmentally controlled chamber, known as the White Room, at the end of the arm. The White Room provides entrance for the astronaut crew into the orbiter. On either side of the tail and main engines are the tail service masts. Rising 31 feet above the Mobile Launcher Platform, the tail masts provide umbilical connections for liquid oxygen and liquid hydrogen lines to fuel the external tank from storage tanks adjacent to the launch pad. Discovery carries the Multi-Purpose Logistics Module Leonardo, the primary delivery system used to resupply and return Station cargo requiring a pressurized environment. Leonardo will deliver up to 10 tons of laboratory racks filled with equipment, experiments and supplies for outfitting the newly installed U.S. Laboratory Destiny. Launch on mission STS-102 is scheduled March 8 at 6:42 a.m. EST

Distorted secretory granule composition in mast cells with multiple protease deficiency.

PubMed

Grujic, Mirjana; Calounova, Gabriela; Eriksson, Inger; Feyerabend, Thorsten; Rodewald, Hans-Reimer; Tchougounova, Elena; Kjellén, Lena; Pejler, Gunnar

2013-10-01

Mast cells are characterized by an abundance of secretory granules densely packed with inflammatory mediators such as bioactive amines, cytokines, serglycin proteoglycans with negatively charged glycosaminoglycan side chains of either heparin or chondroitin sulfate type, and large amounts of positively charged proteases. Despite the large biological impact of mast cell granules and their contents on various pathologies, the mechanisms that regulate granule composition are incompletely understood. In this study, we hypothesized that granule composition is dependent on a dynamic electrostatic interrelationship between different granule compounds. As a tool to evaluate this possibility, we generated mice in which mast cells are multideficient in a panel of positively charged proteases: the chymase mouse mast cell protease-4, the tryptase mouse mast cell protease-6, and carboxypeptidase A3. Through a posttranslational effect, mast cells from these mice additionally lack mouse mast cell protease-5 protein. Mast cells from mice deficient in individual proteases showed normal morphology. In contrast, mast cells with combined protease deficiency displayed a profound distortion of granule integrity, as seen both by conventional morphological criteria and by transmission electron microscopy. An assessment of granule content revealed that the distorted granule integrity in multiprotease-deficient mast cells was associated with a profound reduction of highly negatively charged heparin, whereas no reduction in chondroitin sulfate storage was observed. Taken together with previous findings showing that the storage of basic proteases conversely is regulated by anionic proteoglycans, these data suggest that secretory granule composition in mast cells is dependent on a dynamic interrelationship between granule compounds of opposite electrical charge.

Deficient Differentiation of Mast Cells in the Skin of mi/mi Mice

PubMed Central

Kasugai, Tsutomu; Oguri, Kayoko; Jippo-Kanemoto, Tomoko; Morimoto, Masahiro; Yamatodani, Atsushi; Yoshida, Keiichi; Ebi, Yoshitaka; Isozaki, Koji; Tei, Hideki; Tsujimura, Tohru; Nomura, Shintaro; Okayama, Minoru; Kitamura, Yukihiko

1993-01-01

The staining property of skin mast cells changed from Alcian blue+/berberine sulfate- to Alcian blue +/berberine sulfate+ in the skin of normal (+/+) and Wv/Wv mice. In contrast, this change did not occur in the skin of mi/mi mice. Heparin content and histamine content per a mi/mi skin mast cell were estimated to be 34% and 18% those of a +/+ skin mast cell, respectively. The low heparin content of mi/mi skin mast cells seemed to be consistent with the Alcian blue+/berberine sulfate- staining property. Expression of genes encoding mast cell-specific proteolytic enzymes was examined by Northern blotting and in situ hybridization. Messenger RNA of mast cell carboxypeptidase A was expressed most of all by +/+, WV Wv/W+ and mi/mi skin mast cells, but mRNA of mouse mast cell protease (MMCP)-6 was expressed by approximately a half of +/+ and Wv/Wv skin mast cells and by only 3% of mi/mi skin mast cells. A significant amount of MMCP-2 mRNA was not expressed in the skin of all +/+, Wv/Wv and mi/mi mice. This shows the presence of at least three phenotypes in skin mast cells of mice: berberine sulfate+/MMCP-6+, berberine sulfate+/MMCP-6-, and berberine sulfate-/ MMCP-6-. The in situ hybridization of mRNA of mast cell-specific proteolytic enzymes seemed to be useful to describe abnormalities of mast cell differentiation in the skin of mi/mi mice. ImagesFigure 4Figure 5 PMID:8238251

Mast cells in the human lung at high altitude

NASA Astrophysics Data System (ADS)

Heath, Donald

1992-12-01

Mast cell densities in the lung were measured in five native highlanders of La Paz (3600 m) and in one lowlander dying from high-altitude pulmonary oedema (HAPO) at 3440 m. Two of the highlanders were mestizos with normal pulmonary arteries and the others were Aymara Indians with muscular remodelling of their pulmonary vasculature. The aim of the investigation was to determine if accumulation of mast cells in the lung at high altitude (HA) is related to alveolar hypoxia alone, to a combination of hypoxia and muscularization of the pulmonary arterial tree, or to oedema of the lung. The lungs of four lowlanders were used as normoxic controls. The results showed that the mast cell density of the two Mestizos was in the normal range of lowlanders (0.6-8.8 cells/mm2). In the Aymara Indians the mast cell counts were raised (25.6-26.0 cells/mm2). In the lowlander dying from HAPO the mast cell count was greatly raised to 70.1 cells/mm2 lung tissue. The results show that in native highlanders an accumulation of mast cells in the lung is not related to hypoxia alone but to a combination of hypoxia and muscular remodelling of the pulmonary arteries. However, the most potent cause of increased mast cell density in the lung at high altitude appears to be high-altitude pulmonary oedema.

Antibacterial agent triclosan suppresses RBL-2H3 mast cell function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palmer, Rachel K., E-mail: rachel.palmer@maine.edu; Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469; Hutchinson, Lee M.

2012-01-01

Triclosan is a broad-spectrum antibacterial agent, which has been shown previously to alleviate human allergic skin disease. The purpose of this study was to investigate the hypothesis that the mechanism of this action of triclosan is, in part, due to effects on mast cell function. Mast cells play important roles in allergy, asthma, parasite defense, and carcinogenesis. In response to various stimuli, mast cells degranulate, releasing allergic mediators such as histamine. In order to investigate the potential anti-inflammatory effect of triclosan on mast cells, we monitored the level of degranulation in a mast cell model, rat basophilic leukemia cells, clonemore » 2H3. Having functional homology to human mast cells, as well as a very well defined signaling pathway leading to degranulation, this cell line has been widely used to gain insight into mast-cell driven allergic disorders in humans. Using a fluorescent microplate assay, we determined that triclosan strongly dampened the release of granules from activated rat mast cells starting at 2 μM treatment, with dose-responsive suppression through 30 μM. These concentrations were found to be non-cytotoxic. The inhibition was found to persist when early signaling events (such as IgE receptor aggregation and tyrosine phosphorylation) were bypassed by using calcium ionophore stimulation, indicating that the target for triclosan in this pathway is likely downstream of the calcium signaling event. Triclosan also strongly suppressed F-actin remodeling and cell membrane ruffling, a physiological process that accompanies degranulation. Our finding that triclosan inhibits mast cell function may explain the clinical data mentioned above and supports the use of triclosan or a mechanistically similar compound as a topical treatment for allergic skin disease, such as eczema. -- Highlights: ►The effects of triclosan on mast cell function using a murine mast cell model. ►Triclosan strongly inhibits degranulation of mast

Tenth Aerospace Mechanisms Symposium

NASA Technical Reports Server (NTRS)

1976-01-01

Design studies and analyses were performed to describe the loads and dynamics of the space shuttle tail service masts. Of particular interest is the motion and interaction of the umbilical carrier plate, lanyard system, vacuum jacketed hoses, latches, links, and masthead.

KSC01PD1742

NASA Image and Video Library

2001-11-28

KENNEDY SPACE CENTER, Fla. -- Space Shuttle Endeavour is revealed after rollback of the Rotating Service Structure on Launch Pad 39B. Seen is one of the twin solid rocket boosters that flank the orange external tank. Above the external tank is the Gaseous Oxygen Vent Arm that vents gaseous oxygen vapors away from the Shuttle. The vent hood assembly at the end is often referred to as the "beanie cap." Stretching to the crew hatch on the side is the Orbiter Access Arm with its environmentally controlled White Room at the end. The Shuttle sits on the Mobile Launcher Platform with the two service tail masts on either side of the main engines. The tail masts support the fluid, gas and electrical requirements of the orbiter's liquid oxygen and liquid hydrogen aft T-0 umbilicals. Each tail mast is 31 feet (9.4 meters) high, 15 feet (4.6 meters) long and 9 feet (3.1 meters) wide. Endeavour is scheduled to launch on mission STS-108 Nov. 29 at 7:41 p.m. On this 12th flight to the International Space Station, known as a Utilization Flight, Endeavour will carry a crew of four plus the Expedition 4 crew, who will replace Expedition 3 aboard the ISS. The payload includes the Multi-Purpose Logistics Module Raffaello, filled with supplies, equipment and experiments

KSC01PD1743

NASA Image and Video Library

2001-11-28

KENNEDY SPACE CENTER, Fla. -- After rollback of the Rotating Service Structure on Launch Pad 39B, Space Shuttle Endeavour is bathed in light. Seen is one of the twin solid rocket boosters that flank the orange external tank. Above the external tank is the Gaseous Oxygen Vent Arm that vents gaseous oxygen vapors away from the Shuttle. The vent hood assembly at the end is often referred to as the "beanie cap." Stretching to the crew hatch on the side is the Orbiter Access Arm with its environmentally controlled White Room at the end. The Shuttle sits on the Mobile Launcher Platform with the two service tail masts on either side of the main engines. The tail masts support the fluid, gas and electrical requirements of the orbiter's liquid oxygen and liquid hydrogen aft T-0 umbilicals. Each tail mast is 31 feet (9.4 meters) high, 15 feet (4.6 meters) long and 9 feet (3.1 meters) wide. Endeavour is scheduled to launch on mission STS-108 Nov. 29 at 7:41 p.m. On this 12th flight to the International Space Station, known as a Utilization Flight, Endeavour will carry a crew of four plus the Expedition 4 crew, who will replace Expedition 3 aboard the ISS. The payload includes the Multi-Purpose Logistics Module Raffaello, filled with supplies, equipment and experiments

Imaging immune response of skin mast cells in vivo with two-photon microscopy

NASA Astrophysics Data System (ADS)

Li, Chunqiang; Pastila, Riikka K.; Lin, Charles P.

2012-02-01

Intravital multiphoton microscopy has provided insightful information of the dynamic process of immune cells in vivo. However, the use of exogenous labeling agents limits its applications. There is no method to perform functional imaging of mast cells, a population of innate tissue-resident immune cells. Mast cells are widely recognized as the effector cells in allergy. Recently their roles as immunoregulatory cells in certain innate and adaptive immune responses are being actively investigated. Here we report in vivo mouse skin mast cells imaging with two-photon microscopy using endogenous tryptophan as the fluorophore. We studied the following processes. 1) Mast cells degranulation, the first step in the mast cell activation process in which the granules are released into peripheral tissue to trigger downstream reactions. 2) Mast cell reconstitution, a procedure commonly used to study mast cells functioning by comparing the data from wild type mice, mast cell-deficient mice, and mast-cell deficient mice reconstituted with bone marrow-derived mast cells (BMMCs). Imaging the BMMCs engraftment in tissue reveals the mast cells development and the efficiency of BMMCs reconstitution. We observed the reconstitution process for 6 weeks in the ear skin of mast cell-deficient Kit wsh/ w-sh mice by two-photon imaging. Our finding is the first instance of imaging mast cells in vivo with endogenous contrast.

43. TOP PART OF UMBILICAL MAST, NORTH AND WEST SIDES. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

43. TOP PART OF UMBILICAL MAST, NORTH AND WEST SIDES. AIR CONDITIONING DUCTING IS VISIBLE ON INTERIOR OF MAST. RAIL IS VISIBLE LEFT OF THE MAST. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

42. VIEW OF UMBILICAL MAST AND LAUNCH PAD FROM MST ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

42. VIEW OF UMBILICAL MAST AND LAUNCH PAD FROM MST BASE. LAUNCHER IS BEHIND UMBILICAL MAST AND RAIL SYSTEM IS PARALLEL TO MAST ON RIGHT AND LEFT. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

The role of mast cells in oral squamous cell carcinoma

PubMed Central

Gudiseva, Swetha; Chitturi, Raviteja; Anumula, Vamsikrishna; Poosarla, Chandrashekar; Baddam, Venkat Ramana Reddy

2017-01-01

The mast cells are initial effective lineage in both humoral and adaptive immunity. They are ubiquitous in skin, mucosa, and in function. They contain biologically essential and dynamic mediators in healthy and harmful conditions of tissue. Mast cell malfunctioning could be attributed to various chronic allergic diseases. Considerately, emerging evidence of mast cell involvement in various cancers shows them to have both positive and negative roles in tumour growth. It mostly indulges in tumour progression and metastasis via angiogenesis, extracellular matrix degradation, and mitogenic activity in the tumour microenvironment. The current paper reviewed research papers on mast cells in oral squamous cell carcinoma through the PubMed database from 1980 to the present date. The present paper is an attempt to summarise the research reports on the role of mast cells in oral squamous cell carcinoma. Further to this note, this paper also outlines the role of mast cells in normal physiological processes and tumour biology. PMID:28435394

Mast cell heterogeneity underlies different manifestations of food allergy in mice

PubMed Central

Benedé, Sara

2018-01-01

Food can trigger a diverse array of symptoms in food allergic individuals from isolated local symptoms affecting skin or gut to multi-system severe reactions (systemic anaphylaxis). Although we know that gastrointestinal and systemic manifestations of food allergy are mediated by tissue mast cells (MCs), it is not clear why allergen exposure by the oral route can result in such distinct clinical manifestations. Our aim was to assess the contribution of mast cell subsets to different manifestations of food allergy. We used two common models of IgE-mediated food allergy, one resulting in systemic anaphylaxis and the other resulting in acute gastrointestinal symptoms, to study the immune basis of allergic reactions. We used responders and non-responders in each model system, as well as naïve controls to identify the association of mast cell activation with clinical reactivity rather than sensitization. Systemic anaphylaxis was uniquely associated with activation of connective tissue mast cells (identified by release of mouse mast cell protease (MMCP) -7 into the serum) and release of histamine, while activation of mucosal mast cells (identified by release of MMCP-1 in the serum) did not correlate with symptoms. Gastrointestinal manifestations of food allergy were associated with an increase of MMCP-1-expressing mast cells in the intestine, and evidence of both mucosal and connective tissue mast cell activation. The data presented in this paper demonstrates that mast cell heterogeneity is an important contributor to manifestations of food allergy, and identifies the connective tissue mast cell subset as key in the development of severe systemic anaphylaxis. PMID:29370173

Extendable mast used in one shot soil penetrometer

NASA Technical Reports Server (NTRS)

Hotz, G. M.; Howard, G. A.

1966-01-01

Penetrometer to test soil characteristics has a piercing head with soil instrumentation equipment attached to an expandable mast actuated by compressed air. The penetrometer gives continuous measurements as the mast pushes the piercing head through the soil.

Calcium Imaging of Nerve-Mast Cell Signaling in the Human Intestine

PubMed Central

Buhner, Sabine; Barki, Natasja; Greiter, Wolfgang; Giesbertz, Pieter; Demir, Ihsan E.; Ceyhan, Güralp O.; Zeller, Florian; Daniel, Hannelore; Schemann, Michael

2017-01-01

Introduction: It is suggested that an altered microenvironment in the gut wall alters communication along a mast cell nerve axis. We aimed to record for the first time signaling between mast cells and neurons in intact human submucous preparations. Methods: We used the Ca2+ sensitive dye Fluo-4 AM to simultaneously image changes in intracellular calcium [Ca+2]i (%ΔF/F) in neurons and mast cells. Data are presented as median with interquartile ranges (25/75%). Results: We recorded nerve responses in 29 samples upon selective activation of 223 mast cells by IgE receptor cross linking with the antibody mAb22E7. Mast cells responded to mAb22E7 with a median [Ca+2]i increase of 20% (11/39) peaking 90 s (64/144) after the application. Only very few neurons responded and the median percentage of responding neuronal area was 0% (0/5.9). Mast cell activation remained in the presence of the fast sodium channel blocker tetrodotoxin. Specific neuronal activation by transmural electrical field stimulation (EFS) in 34 samples evoked instantaneously [Ca+2]i signals in submucous neurons. This was followed by a [Ca+2]i peak response of 8%ΔF/F (4/15) in 33% of 168 mast cells in the field of view. The mast cell response was abolished by the nerve blocker tetrododoxin, reduced by the Calcitonin Gene-Related Peptide receptor 1 antagonist BIBN-4096 and the Vasoactive Intestinal Peptide receptor antagonist PG97-269, but not by blockade of the neurokinin receptors 1–3. Conclusion: The findings revealed bidirectional signaling between mast cells and submucous neurons in human gut. In our macroscopically normal preparations a nerve to mast cell signaling was very prominent whereas a mast cell to nerve signaling was rather rare. PMID:29238306

Increased Differentiation of Dermal Mast Cells in Mice Lacking the Mpl Gene

PubMed Central

Ghinassi, Barbara; Zingariello, Maria; Martelli, Fabrizio; Lorenzini, Rodolfo; Vannucchi, Alessandro M.; Rana, Rosa Alba; Nishikawa, Mitsuo; Migliaccio, Giovanni; Mascarenhas, John

2009-01-01

Thrombopoietin interactions with its receptor, Mpl, play an important role in the regulation of hematopoietic stem/progenitor cell proliferation and differentiation. In this study, we report that the mast cell restricted progenitor cells (MCP) and the mast cell precursors in the bone marrow of wild-type mice express Mpl on their surface. Furthermore, targeted deletion of the Mpl gene in mice decreases the number of MCP while increasing the number of mast cell precursors present in the marrow and spleen. It also increases the number of mast cells present in the dermis, in the peritoneal cavity, and in the gut of the mice. In addition, serosal mast cells from Mplnull mice have a distinctive differentiation profile similar to that expressed by wild-type dermal mast cells. These results suggest that not only does ligation of thrombopoietin with the Mpl receptor exert an effect at the mast cell restricted progenitor cell level, but also plays an unexpected yet important role in mast cell maturation. PMID:19025339

The Michigan Alcoholism Screening Test (MAST): A Statistical Validation Analysis

ERIC Educational Resources Information Center

Laux, John M.; Newman, Isadore; Brown, Russ

2004-01-01

This study extends the Michigan Alcoholism Screening Test (MAST; M. L. Selzer, 1971) literature base by examining 4 issues related to the validity of the MAST scores. Specifically, the authors examine the validity of the MAST scores in light of the presence of impression management, participant demographic variables, and item endorsement…

Changing the threshold-Signals and mechanisms of mast cell priming.

PubMed

Halova, Ivana; Rönnberg, Elin; Draberova, Lubica; Vliagoftis, Harissios; Nilsson, Gunnar P; Draber, Petr

2018-03-01

Mast cells play a key role in allergy and other inflammatory diseases involving engagement of multivalent antigen with IgE bound to high-affinity IgE receptors (FcεRIs). Aggregation of FcεRIs on mast cells initiates a cascade of signaling events that eventually lead to degranulation, secretion of leukotrienes and prostaglandins, and cytokine and chemokine production contributing to the inflammatory response. Exposure to pro-inflammatory cytokines, chemokines, bacterial and viral products, as well as some other biological products and drugs, induces mast cell transition from the basal state into a primed one, which leads to enhanced response to IgE-antigen complexes. Mast cell priming changes the threshold for antigen-mediated activation by various mechanisms, depending on the priming agent used, which alone usually do not induce mast cell degranulation. In this review, we describe the priming processes induced in mast cells by various cytokines (stem cell factor, interleukins-4, -6 and -33), chemokines, other agents acting through G protein-coupled receptors (adenosine, prostaglandin E 2 , sphingosine-1-phosphate, and β-2-adrenergic receptor agonists), toll-like receptors, and various drugs affecting the cytoskeleton. We will review the current knowledge about the molecular mechanisms behind priming of mast cells leading to degranulation and cytokine production and discuss the biological effects of mast cell priming induced by several cytokines. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Arm and Mast of NASA Mars Rover Curiosity

NASA Image and Video Library

2011-04-06

The arm and the remote sensing mast of the Mars rover Curiosity each carry science instruments and other tools for NASA Mars Science Laboratory mission. This image shows the arm on the left and the mast just right of center.

4-Chlorotetrazolo[1,5-a]quinoxaline inhibits activation of Syk kinase to suppress mast cells in vitro and mast cell-mediated passive cutaneous anaphylaxis in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Kui Lea; Ko, Na Young; Lee, Jun Ho

2011-12-15

4-Chlorotetrazolo[1,5-a]quinoxaline is a quinoxaline derivative. We aimed to study the effects of 4-chlorotetrazolo[1,5-a]quinoxaline on activation of mast cells in vitro and in mice. 4-Chlorotetrazolo[1,5-a]quinoxaline reversibly inhibited degranulation of mast cells in a dose-dependent manner, and also suppressed the expression and secretion of TNF-{alpha} and IL-4 in mast cells. Mechanistically, 4-chlorotetrazolo[1,5-a]quinoxaline inhibited activating phosphorylation of Syk and LAT, which are crucial for early Fc{epsilon}RI-mediated signaling events, as well as Akt and MAP kinases, which play essential roles in the production of various pro-inflammatory cytokines in mast cells. Notably, although 4-chlorotetrazolo[1,5-a]quinoxaline inhibited the activation of Fyn and Syk, minimal inhibition was observedmore » in mast cells in the case of Lyn. Furthermore, consistent with its in vitro activity, 4-chlorotetrazolo[1,5-a]quinoxaline significantly suppressed mast cell-mediated passive cutaneous anaphylaxis in mice. In summary, the results from this study demonstrate that 4-chlorotetrazolo[1,5-a]quinoxaline shows an inhibitory effect on mast cells in vitro and in vivo, and that this is mediated by inhibiting the activation of Syk in mast cells. Therefore, 4-chlorotetrazolo[1,5-a]quinoxaline could be useful in the treatment of mast cell-mediated allergic diseases. -- Highlights: Black-Right-Pointing-Pointer 4-chlorotetrazolo[1,5-a]quinoxaline is a quinoxaline derivative. Black-Right-Pointing-Pointer The effect of 4-chlorotetrazolo[1,5-a]quinoxaline on mast cells was investigated. Black-Right-Pointing-Pointer 4-chlorotetrazolo[1,5-a]quinoxaline reversibly inhibited Syk activation. Black-Right-Pointing-Pointer 4-chlorotetrazolo[1,5-a]quinoxaline could be useful for IgE-mediated allergy.« less

KSC00pp1731

NASA Image and Video Library

2000-11-14

KENNEDY SPACE CENTER, FLA. -- Space Shuttle Endeavour waits on Launch Pad 39B for launch on mission STS-97. Behind it are the orange external tank flanked by two solid rocket boosters. On either side of Endeavour’s tail are the tail service masts, which support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft T-0 umbilicals. The masts also protect the ground half of those umbilicals from the harsh launch environment. At launch, the masts rotate backward, triggering a compressed-gas thruster and causing a protective hood to move into place and completely seal the structure from the main engine exhaust. At the end of the orbiter access arm, near the nose of Endeavour, is the White Room, an environmental chamber that provides both entrance to the orbiter and emergency egress, if needed. The arm remains extended until 7 minutes, 24 seconds before launch. The arm extends from the Fixed Service Structure. In the center of Endeavour are the payload bay doors. Endeavour is scheduled to launch Nov. 30 at 10:06 p.m. EST

KSC-00pp1731

NASA Image and Video Library

2000-11-14

KENNEDY SPACE CENTER, FLA. -- Space Shuttle Endeavour waits on Launch Pad 39B for launch on mission STS-97. Behind it are the orange external tank flanked by two solid rocket boosters. On either side of Endeavour’s tail are the tail service masts, which support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft T-0 umbilicals. The masts also protect the ground half of those umbilicals from the harsh launch environment. At launch, the masts rotate backward, triggering a compressed-gas thruster and causing a protective hood to move into place and completely seal the structure from the main engine exhaust. At the end of the orbiter access arm, near the nose of Endeavour, is the White Room, an environmental chamber that provides both entrance to the orbiter and emergency egress, if needed. The arm remains extended until 7 minutes, 24 seconds before launch. The arm extends from the Fixed Service Structure. In the center of Endeavour are the payload bay doors. Endeavour is scheduled to launch Nov. 30 at 10:06 p.m. EST

Influence of MRI contrast media on histamine release from mast cells.

PubMed

Kun, Tomasz; Jakubowski, Lucjusz

2012-07-01

Mast cells, owing to diversity of secreted mediators, play a crucial role in the regulation of inflammatory response. Together with basophils, mast cells constitute a central pathogenetic element of anaphylactic (IgE-dependent) and anaphylactoid (IgE-independent) reactions. In severe cases, generalized degranulation of mast cells may cause symptoms of anaphylactic shock. The influence of the classical, iodine-based contrast media on mastocyte degranulation has been fully described. Our objective was to determine the influence of the gadolinium-based MRI contrast media on histamine release from mast cells and to compare the activity of ionic and non-ionic preparations of contrast media. To determine the intensity of mast cell degranulation, we used an experimental model based on mastocytes isolated from rat peritoneal fluid. Purified suspensions of mast cells were incubated with various concentrations of Gd-DTPA and Gd-DTPA-BMA, and solutions of PEG 600 which served as a non-toxic osmotic stimulus. The intensity of mast cell activation was presented as mean percentage of histamine released from cells after incubation. The obtained results demonstrate that both ionic and non-ionic preparations of the MRI contrast media are able to induce mast cell degranulation in vitro. It was also proved that the non-ionic MRI contrast media stimulate mast cells markedly more weakly than ionic contrast media at identical concentration. The aforementioned results may suggest a more profitable safety profile of the non-ionic contrast preparations. We may also conclude that triggering of mast cell degranulation after incubation with the solutions of MRI contrast media results from non-specific osmotic stimulation and direct toxicity of free ionic residues.

Spatial patterns and broad-scale weather cues of beech mast seeding in Europe.

PubMed

Vacchiano, Giorgio; Hacket-Pain, Andrew; Turco, Marco; Motta, Renzo; Maringer, Janet; Conedera, Marco; Drobyshev, Igor; Ascoli, Davide

2017-07-01

Mast seeding is a crucial population process in many tree species, but its spatio-temporal patterns and drivers at the continental scale remain unknown . Using a large dataset (8000 masting observations across Europe for years 1950-2014) we analysed the spatial pattern of masting across the entire geographical range of European beech, how it is influenced by precipitation, temperature and drought, and the temporal and spatial stability of masting-weather correlations. Beech masting exhibited a general distance-dependent synchronicity and a pattern structured in three broad geographical groups consistent with continental climate regimes. Spearman's correlations and logistic regression revealed a general pattern of beech masting correlating negatively with temperature in the summer 2 yr before masting, and positively with summer temperature 1 yr before masting (i.e. 2T model). The temperature difference between the two previous summers (DeltaT model) was also a good predictor. Moving correlation analysis applied to the longest eight chronologies (74-114 yr) revealed stable correlations between temperature and masting, confirming consistency in weather cues across space and time. These results confirm widespread dependency of masting on temperature and lend robustness to the attempts to reconstruct and predict mast years using temperature data. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Multiple bidirectional alterations of phenotype and changes in proliferative potential during the in vitro and in vivo passage of clonal mast cell populations derived from mouse peritoneal mast cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kanakura, Y.; Thompson, H.; Nakano, T.

1988-09-01

Mouse peritoneal mast cells (PMC) express a connective tissue-type mast cell (CTMC) phenotype, including reactivity with the heparin-binding fluorescent dye berberine sulfate and incorporation of (35S) sulfate predominantly into heparin proteoglycans. When PMC purified to greater than 99% purity were cultured in methylcellulose with IL-3 and IL-4, approximately 25% of the PMC formed colonies, all of which contained both berberine sulfate-positive and berberine sulfate-negative mast cells. When these mast cells were transferred to suspension culture, they generated populations that were 100% berberine sulfate-negative, a characteristic similar to that of mucosal mast cells (MMC), and that synthesized predominantly chondroitin sulfate (35S)more » proteoglycans. When ''MMC-like'' cultured mast cells derived from WBB6F1-+/+ PMC were injected into the peritoneal cavities of mast cell-deficient WBB6F1-W/Wv mice, the adoptively transferred mast cell population became 100% berberine sulfate-positive. In methylcellulose culture, these ''second generation PMC'' formed clonal colonies containing both berberine sulfate-positive and berberine sulfate-negative cells, but exhibited significantly less proliferative ability than did normal +/+ PMC. Thus, clonal mast cell populations initially derived from single PMC exhibited multiple and bidirectional alterations between CTMC-like and MMC-like phenotypes. However, this process was associated with a progressive diminution of the mast cells' proliferative ability.« less

Mast Cells Can Enhance Resistance to Snake and Honeybee Venoms

NASA Astrophysics Data System (ADS)

Metz, Martin; Piliponsky, Adrian M.; Chen, Ching-Cheng; Lammel, Verena; Åbrink, Magnus; Pejler, Gunnar; Tsai, Mindy; Galli, Stephen J.

2006-07-01

Snake or honeybee envenomation can cause substantial morbidity and mortality, and it has been proposed that the activation of mast cells by snake or insect venoms can contribute to these effects. We show, in contrast, that mast cells can significantly reduce snake-venom-induced pathology in mice, at least in part by releasing carboxypeptidase A and possibly other proteases, which can degrade venom components. Mast cells also significantly reduced the morbidity and mortality induced by honeybee venom. These findings identify a new biological function for mast cells in enhancing resistance to the morbidity and mortality induced by animal venoms.

Bone marrow-derived cultured mast cells and peritoneal mast cells as targets of a growth activity secreted by BALB/3T3 fibroblasts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jozaki, K.; Kuriu, A.; Hirota, S.

1991-03-01

When fibroblast cell lines were cultured in contact with bone marrow-derived cultured mast cells (CMC), both NIH/3T3 and BALB/3T3 cell lines supported the proliferation of CMC. In contrast, when contact between fibroblasts and CMC was prohibited by Biopore membranes or soft agar, only BALB/3T3 fibroblasts supported CMC proliferation, suggesting that BALB/3T3 but not NIH/3T3 cells secreted a significant amount of a mast cell growth activity. Moreover, the BALB/3T3-derived growth activity induced the incorporation of (3H)thymidine by CMC and the clonal growth of peritoneal mast cells in methylcellulose. The mast cell growth activity appeared to be different from interleukin 3 (IL-3)more » and interleukin 4 (IL-4), because mRNAs for these interleukins were not detectable in BALB/3T3 fibroblasts. Although mast cells are genetically deficient in tissues of W/Wv mice, CMC did develop when bone marrow cells of W/Wv mice were cultured with pokeweed mitogen-stimulated spleen cell-conditioned medium. Because BALB/3T3 fibroblast-conditioned medium (BALB-FCM) did not induce the incorporation of (3H)thymidine by W/Wv CMC, the growth activity in BALB-FCM appeared to be a ligand for the receptor encoded by the W (c-kit) locus. Because CMC and peritoneal mast cells are obtained as homogeneous suspensions rather easily, these cells may be potentially useful as targets for the fibroblast-derived mast cell growth activity.« less

The effect of capsaicin application on mast cells in normal human skin.

PubMed

Bunker, C B; Cerio, R; Bull, H A; Evans, J; Dowd, P M; Foreman, J C

1991-05-01

Peptides released from sensory nerves during an axon reflex are thought to cause mast cell degranulation, histamine (Hi) release and Hi-induced vasodilatation leading to the flare of the triple response. Capsaicin stimulates peptide release from sensory neurones and causes flare in vivo but does not cause Hi release from mast cells in vitro. The effects of capsaicin on mast cell degranulation in human skin in vivo has been studied by histological examination of skin biopsies after topical capsicin (1%) treatment of stratum corneum-denuded forearm in four volunteers. The results show a significant reduction in the visible numbers of mast cells and the appearance of degranulated mast cells ghosts in the skin six hours after capsaicin application. Since capsaicin itself does not release Hi from mast cells, these data suggest that capsaicin-induced release of peptides from neurones could cause mast cell degranulation.

Alterations in MAST suit pressure with changes in ambient temperature.

PubMed

Sanders, A B; Meislin, H W; Daub, E

1983-01-01

A study was undertaken to test the hypothesis that change in ambient air temperature has an effect on MAST suit pressure according to the ideal gas law. Two different MAST suits were tested on Resusci-Annie dummies. The MAST suits were applied in a cold room at 4.4 degrees C and warmed to 44 degrees C. Positive linear correlations were found in nine trials, but the two suits differed in their rate of increase in pressure. Three trials using humans were conducted showing increased pressure with temperature but at a lesser rate than with dummies. A correlation of 0.5 to 1.0 mm Hg increase in MAST suit pressure for each 1.0 degrees C increase in ambient temperature was found. Implications are discussed for the use of the MAST suit in environmental conditions where the temperature changes.

Benzoxazole derivatives suppress lipopolysaccharide-induced mast cell activation.

PubMed

Cho, Kyung-Ah; Park, Minhwa; Kim, Yu-Hee; Choo, Hea-Young Park; Lee, Kyung Ho

2018-05-01

Mast cells are central regulators of allergic inflammation that function by releasing various proallergic inflammatory mediators, including histamine, eicosanoids and proinflammatory cytokines. Occasionally, bacterial infections may initiate or worsen allergic inflammation. A number of studies have indicated that activation of lipoxygenase in mast cells positive regulates allergic inflammatory responses by generating leukotrienes and proinflammatory cytokines. In the present study, the effects of benzoxazole derivatives on the lipopolysaccharide (LPS)‑induced expression of proinflammatory cytokines, production of histamine and surface expression of co‑stimulatory molecules on bone marrow-derived mast cells (BMMCs) were studied. The benzoxazole derivatives significantly reduced the expression of interleukin (IL)‑1β, IL‑6, IL‑13, tumor necrosis factor‑α, perilipin (PLIN) 2, and PLIN3 in BMMCs treated with LPS. Furthermore, histamine production was suppressed in BMMCs treated with LPS, or treated with phorbol-12-myristate-13-acetate/ionomycin. Benzoxazole derivatives marginally affected the surface expression of cluster of differentiation (CD)80 and CD86 on BMMCs in the presence of LPS, although LPS alone did not increase the expression of those proteins. Therefore, benzoxazole derivatives inhibited the secretion of proinflammatory cytokines in mast cells and may be potential candidate anti‑allergic agents to suppress mast cell activation.

Giardia lamblia: identification of molecules that contribute to direct mast cell activation.

PubMed

Muñoz-Cruz, Samira; Gomez-García, Argelia; Matadamas-Martínez, Félix; Alvarado-Torres, Juan A; Meza-Cervantez, Patricia; Arriaga-Pizano, Lourdes; Yépez-Mulia, Lilián

2018-06-02

Mast cells play a central role in the early clearance of the intestinal parasite Giardia lamblia. In a previous study, we reported that G. lamblia live trophozoites or trophozoite-derived total soluble extract induced direct activation (IgE-independent) of mast cells and release of IL-6 and TNF-α. To identify the Giardia molecules and the mast cell receptors involved in this activation, trophozoite-derived total soluble proteins separated into three fractions (F1-F3) were evaluated for its ability to activate mast cells in vitro. F2 activated mast cells in a greater extent than F1 and F3. Furthermore, F2 induced the release of IL-6 and TNF-α by mast cells. TLR2 and TLR4 expression increased slightly after mast cell stimulation with either F2 or total soluble extract; however, these receptors were not involved in F2 or total soluble extract-induced proinflammatory cytokine production. Proteins present in F2 as unique and high-intensity bands identified by liquid chromatography coupled with tandem mass spectrometry, include molecules with important biological activities such as enolase and arginine deiminase (ADI). Recombinant ADI and enolase were tested for their ability to activate mast cells, but only ADI induced a significant release of IL-6 and TNF-α. ADI product, citrulline but not ammonium, also induced mast cell release of TNF-α. Interestingly, recombinant ADI still stimulated the secretion of TNF-α by mast cells in a arginine-free medium, although in a lower extend that in the presence of arginine, indicating that either ADI itself can stimulate mast cells or through its metabolic product, citrulline.

Comparison of Mast Cells and Inflammatory Cells within Periapical Lesions and Comparison of Degranulated Mast Cells Between Fibrous and Inflamed Area in Radicular Cysts: An Immunohistochemical Study

PubMed Central

Sood, Rahul; Akifuddin, Syed; Sidhu, Gagandeep Kaur; Khan, Nadia; Singla, Kapil

2014-01-01

Objective: The role of mast cells as the key effector of allergic inflammation, anaphylactic inflammatory reactions and in the pathogenesis of chronic inflammation, is well-known. The present study is adopted to compare mast cells and inflammatory cells within periapical granuloma and cysts and localize the mast cells and quantify their number in the periapical cysts so as to propose a role of mast cells in the pathogenesis of this lesion. Materials and Methods: Biopsy specimens of 30 periapical lesions were stained with hematoxylin–eosin, and immunohistochemical Mast Cell Tryptase from Bio SB (IHC detection system kit) antibody. The tryptase positive mast cells and mononuclear inflammatory cells were counted in 10 consecutive high power fields (100X) using the binocular microscope from Motic attached to a computer with Motic Advanced Images 3.2 software. Results: Comparative microscopic analysis indicated that periapical cyst shows more percentage of mast cells and less percentage of inflammatory cell than periapical granuloma (comparison of mean and standard deviation of total number of mast cells and inflammatory cells, mast cells 3.15±1.39 in the granuloma group and 4.43±1.91in the cyst group, inflammatory cells, 67.11±1.2 in the granuloma group and 52.66±0.8 in the cyst group). Numerous degranulated mast cells were observed in the fibrous wall than the inflammatory infiltrate of the periapical cysts. The mean and standard deviation of degranulated mast cells between the inflammatory and fibrous zone within the cyst group, being 0.95±1.10 and1.68±1.34 respectively. The values varied significantly between the two zones. Conclusion: The number of inflammatory cells in the cyst group is less than periapical granuloma and total number of mast cells in the cyst group is more as compared to periapical granuloma. The degranulated cells were quantified and they were higher in the fibrous area of the cysts than the inflammatory zone. This study could support the

Comparison of Mast Cells and Inflammatory Cells within Periapical Lesions and Comparison of Degranulated Mast Cells Between Fibrous and Inflamed Area in Radicular Cysts: An Immunohistochemical Study.

PubMed

Shiromany, Aseem; Sood, Rahul; Akifuddin, Syed; Sidhu, Gagandeep Kaur; Khan, Nadia; Singla, Kapil

2014-12-01

The role of mast cells as the key effector of allergic inflammation, anaphylactic inflammatory reactions and in the pathogenesis of chronic inflammation, is well-known. The present study is adopted to compare mast cells and inflammatory cells within periapical granuloma and cysts and localize the mast cells and quantify their number in the periapical cysts so as to propose a role of mast cells in the pathogenesis of this lesion. Biopsy specimens of 30 periapical lesions were stained with hematoxylin-eosin, and immunohistochemical Mast Cell Tryptase from Bio SB (IHC detection system kit) antibody. The tryptase positive mast cells and mononuclear inflammatory cells were counted in 10 consecutive high power fields (100X) using the binocular microscope from Motic attached to a computer with Motic Advanced Images 3.2 software. Comparative microscopic analysis indicated that periapical cyst shows more percentage of mast cells and less percentage of inflammatory cell than periapical granuloma (comparison of mean and standard deviation of total number of mast cells and inflammatory cells, mast cells 3.15±1.39 in the granuloma group and 4.43±1.91in the cyst group, inflammatory cells, 67.11±1.2 in the granuloma group and 52.66±0.8 in the cyst group). Numerous degranulated mast cells were observed in the fibrous wall than the inflammatory infiltrate of the periapical cysts. The mean and standard deviation of degranulated mast cells between the inflammatory and fibrous zone within the cyst group, being 0.95±1.10 and1.68±1.34 respectively. The values varied significantly between the two zones. The number of inflammatory cells in the cyst group is less than periapical granuloma and total number of mast cells in the cyst group is more as compared to periapical granuloma. The degranulated cells were quantified and they were higher in the fibrous area of the cysts than the inflammatory zone. This study could support the fact that the various mediators released on

53. VIEW FROM FLOOR OF MAST TRENCH SHOWING BASE OF ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

53. VIEW FROM FLOOR OF MAST TRENCH SHOWING BASE OF ERECT UMBILICAL MAST. AIR-CONDITIONING DUCTS VISIBLE ON RIGHT SIDE OF MAST. HYDRAULIC ACTUATOR ARMS FOR OPENING TRENCH DOORS VISIBLE ON LEFT SIDE OF PHOTO. 'DOOR STOP' PEDESTAL IN FOREGROUND. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Self-anchoring mast for deploying a high-speed submersible mixer in a tank

DOEpatents

Cato, Jr., Joseph E.; Shearer, Paul M [Aiken, SC; Rodwell, Philip O [Evans, GA

2004-10-12

A self-anchoring mast for deploying a high-speed submersible mixer in a tank includes operably connected first and second mast members (20, 22) and a foot member 46 operably connected to the second mast member for supporting the mast in a tank. The second mast member includes a track (36, 38) for slidably receiving a bearing of the mixer to change the orientation of the mixer in the tank.

A poloidal section neutron camera for MAST upgrade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sangaroon, S.; Weiszflog, M.; Cecconello, M.

2014-08-21

The Mega Ampere Spherical Tokamak Upgrade (MAST Upgrade) is intended as a demonstration of the physics viability of the Spherical Tokamak (ST) concept and as a platform for contributing to ITER/DEMO physics. Concerning physics exploitation, MAST Upgrade plasma scenarios can contribute to the ITER Tokamak physics particularly in the field of fast particle behavior and current drive studies. At present, MAST is equipped with a prototype neutron camera (NC). On the basis of the experience and results from previous experimental campaigns using the NC, the conceptual design of a neutron camera upgrade (NC Upgrade) is being developed. As part ofmore » the MAST Upgrade, the NC Upgrade is considered a high priority diagnostic since it would allow studies in the field of fast ions and current drive with good temporal and spatial resolution. In this paper, we explore an optional design with the camera array viewing the poloidal section of the plasma from different directions.« less

Mast Cells and Irritable Bowel Syndrome: From the Bench to the Bedside

PubMed Central

Zhang, Lei; Song, Jun; Hou, Xiaohua

2016-01-01

Irritable bowel syndrome (IBS) is traditionally defined as a functional disorder since it lacks demonstrable pathological abnormalities. However, in recent years, low grade inflammatory infiltration, often rich in mast cells, in both the small and large bowel, has been observed in some patients with IBS. The close association of mast cells with major intestinal functions, such as epithelial secretion and permeability, neuroimmune interactions, visceral sensation, and peristalsis, makes researchers and gastroenterologists to focus attention on the key roles of mast cells in the pathogenesis of IBS. Numerous studies have been carried out to identify the mechanisms in the development, infiltration, activation, and degranulation of intestinal mast cells, as well as the actions of mast cells in the processes of mucosal barrier disruption, mucosal immune dysregulation, visceral hypersensitivity, dysmotility, and local and central stress in IBS. Moreover, therapies targeting mast cells, such as mast cell stabilizers (cromoglycate and ketotifen) and antagonists of histamine and serotonin receptors, have been tried in IBS patients, and have partially exhibited considerable efficacy. This review focuses on recent advances in the role of mast cells in IBS, with particular emphasis on bridging experimental data with clinical therapeutics for IBS patients. PMID:26755686

Brain mast cells link the immune system to anxiety-like behavior

PubMed Central

Nautiyal, Katherine M.; Ribeiro, Ana C.; Pfaff, Donald W.; Silver, Rae

2008-01-01

Mast cells are resident in the brain and contain numerous mediators, including neurotransmitters, cytokines, and chemokines, that are released in response to a variety of natural and pharmacological triggers. The number of mast cells in the brain fluctuates with stress and various behavioral and endocrine states. These properties suggest that mast cells are poised to influence neural systems underlying behavior. Using genetic and pharmacological loss-of-function models we performed a behavioral screen for arousal responses including emotionality, locomotor, and sensory components. We found that mast cell deficient KitW−sh/W−sh (sash−/−) mice had a greater anxiety-like phenotype than WT and heterozygote littermate control animals in the open field arena and elevated plus maze. Second, we show that blockade of brain, but not peripheral, mast cell activation increased anxiety-like behavior. Taken together, the data implicate brain mast cells in the modulation of anxiety-like behavior and provide evidence for the behavioral importance of neuroimmune links. PMID:19004805

Brain mast cells link the immune system to anxiety-like behavior.

PubMed

Nautiyal, Katherine M; Ribeiro, Ana C; Pfaff, Donald W; Silver, Rae

2008-11-18

Mast cells are resident in the brain and contain numerous mediators, including neurotransmitters, cytokines, and chemokines, that are released in response to a variety of natural and pharmacological triggers. The number of mast cells in the brain fluctuates with stress and various behavioral and endocrine states. These properties suggest that mast cells are poised to influence neural systems underlying behavior. Using genetic and pharmacological loss-of-function models we performed a behavioral screen for arousal responses including emotionality, locomotor, and sensory components. We found that mast cell deficient Kit(W-sh/W-sh) (sash(-/-)) mice had a greater anxiety-like phenotype than WT and heterozygote littermate control animals in the open field arena and elevated plus maze. Second, we show that blockade of brain, but not peripheral, mast cell activation increased anxiety-like behavior. Taken together, the data implicate brain mast cells in the modulation of anxiety-like behavior and provide evidence for the behavioral importance of neuroimmune links.

Hepatic mucosal mast cell hyperplasia in rats with secondary biliary cirrhosis.

PubMed

Rioux, K P; Sharkey, K A; Wallace, J L; Swain, M G

1996-04-01

Mast cells have been shown to play a role in many chronic inflammatory and fibrotic disorders. However, their possible contribution to the pathological changes that occur in liver cirrhosis is unknown. To explore this, we examined whether changes in hepatic mast cell number and mediator content were associated with fibrotic changes in experimental biliary cirrhosis. Rats were studied 7, 14, or 21 days after bile duct resection (BDR). Hepatic mast cells were identified by histochemical and immunohistochemical stains. Rat mast cell protease II (RMCP-II), a marker of mast cell degranulation, was measured in liver by enzyme-linked immunosorbent assay. Hepatic collagen deposition was assessed by Sirius Red F3BA staining. In day 21 BDR rats, there was a one- to twofold increase (P < .001) in the number of hepatic mast cells, but this was not observed in day 7 or 14 BDR rats. Mild fibrotic changes were noted in BDR rat livers as early as 7 days after induction of cholestasis. Significant expansion and organization of fibrous tissue had occurred in day 14 BDR rats which progressed to bridging fibrosis by day 21. Liver RMCP-II levels were decreased by 50 percent (P < .05) and mast cell degranulation was apparent as shown by histamine immunostaining. These results suggest that hepatic mast cell hyperplasia and degranulation occur during prolonged cholestasis in the rat. Although these changes do not correlate with the onset of hepatic fibrosis, they do occur at a time during which there is significant deposition and organization extracellular matrix elements. Hepatic mast cells, by releasing profibrogenic mediators, may contribute to fibrotic changes in biliary cirrhosis.

Lysophosphatidic acid triggers mast cell-driven atherosclerotic plaque destabilization by increasing vascular inflammation.

PubMed

Bot, Martine; de Jager, Saskia C A; MacAleese, Luke; Lagraauw, H Maxime; van Berkel, Theo J C; Quax, Paul H A; Kuiper, Johan; Heeren, Ron M A; Biessen, Erik A L; Bot, Ilze

2013-05-01

Lysophosphatidic acid (LPA), a bioactive lysophospholipid, accumulates in the atherosclerotic plaque. It has the capacity to activate mast cells, which potentially exacerbates plaque progression. In this study, we thus aimed to investigate whether LPA contributes to plaque destabilization by modulating mast cell function. We here show by an imaging mass spectrometry approach that several LPA species are present in atherosclerotic plaques. Subsequently, we demonstrate that LPA is a potent mast cell activator which, unlike other triggers, favors release of tryptase. Local perivascular administration of LPA to an atherosclerotic carotid artery segment increases the activation status of perivascular mast cells and promotes intraplaque hemorrhage and macrophage recruitment without impacting plaque cell apoptosis. The mast cell stabilizer cromolyn could prevent intraplaque hemorrhage elicited by LPA-mediated mast cell activation. Finally, the involvement of mast cells in these events was further emphasized by the lack of effect of perivascular LPA administration in mast cell deficient animals. We demonstrate that increased accumulation of LPA in plaques induces perivascular mast cell activation and in this way contributes to plaque destabilization in vivo. This study points to local LPA availability as an important factor in atherosclerotic plaque stability.

Characterization and modulation of canine mast cell derived eicosanoids

PubMed Central

Lin, Tzu-Yin; London, Cheryl A.

2013-01-01

Mast cells play an important role in both innate and acquired immunity as well as several pathological conditions including allergy, arthritis and neoplasia. They influence these processes by producing a variety of mediators including cytokines, chemokines and eicosanoids. Very little is currently known about the spectrum of inflammatory mediators, particularly eicosanoids (prostaglandins and leukotrienes), produced by canine mast cells. This is important since modulating mast cell derived eicosanoids may help in the treatment of autoimmune and inflammatory disorders. The purpose of this study was to investigate the spectrum of eicosanoids produced by normal canine mast cells and to evaluate the effects of cytokines and non-steroidal anti-inflammatory mediators (NSAIDS) on eicosanoid production and release. Canine bone marrow derived cultured mast cells (cBMCMCs) expressed COX-1, COX-2, and 5-LOX and synthesized and released PGD2, PGE2, LTB4, and LTC4 following activation by a variety of stimuli. The selective COX-2 NSAIDs carprofen (Rimadyl®) and deracoxib (Deramaxx®) inhibited PGD2 and PGE2 production but only slightly inhibited LTB4 and LTC4. The mixed COX-1/COX-2 inhibitor piroxicam blocked PGD2 and PGE2 production, but upregulated LTC4 following treatment while tepoxilan (Zubrin®), a pan COX/LOX inhibitor, markedly reduced the production of all eicosanoids. The LOX inhibitor nordihydroguaiaretic acid (NDGA) prevented LTB4/LTC4 release and BMBMC degranulation. Pre-incubation of cBMCMCs with IL-4 and SCF sensitized these cells to degranulation in response to substance P. In conclusion, canine BMCMCs produce an array of eicosanoids similar to those produced by mast cells from other species. Tepoxilan appeared to be the most effective NSAID for blocking eicosanoid production and thus may be useful for modulating mast cell mediated responses in dogs. PMID:20036014

KSC01PD1763

NASA Image and Video Library

2001-12-03

KENNEDY SPACE CENTER, Fla. -- After rollback of the Rotating Service Structure on Launch Pad 39B, Space Shuttle Endeavour is bathed in light. Twin solid rocket boosters flank the orange external tank behind Endeavour. Above the external tank is the Gaseous Oxygen Vent Arm that vents gaseous oxygen vapors away from the Shuttle. The vent hood assembly at the end is often referred to as the "beanie cap." Stretching to the crew hatch on the side of Endeavour is the Orbiter Access Arm with its environmentally controlled White Room at the end, through which the crew enters the vehicle. The Shuttle sits on the Mobile Launcher Platform with the two service tail masts on either side of the main engines. The tail masts support the fluid, gas and electrical requirements of the orbiter's liquid oxygen and liquid hydrogen aft T-0 umbilicals. Each tail mast is 31 feet (9.4 meters) high, 15 feet (4.6 meters) long and 9 feet (3.1 meters) wide. Endeavour is scheduled to launch on mission STS-108 Dec. 4 at 5:45 p.m. EST. On this 12th flight to the International Space Station, known as a Utilization Flight, Endeavour will carry a crew of four plus the Expedition 4 crew, who will replace Expedition 3 aboard the ISS. The payload includes the Multi-Purpose Logistics Module Raffaello, filled with supplies, equipment and experiments

Human intestinal mucosal mast cells: expanded population in untreated coeliac disease.

PubMed Central

Strobel, S; Busuttil, A; Ferguson, A

1983-01-01

Previous retrospective studies of intestinal mucosal mast cells in coeliac disease have given divergent results, and we have recently reported that inappropriate methodology could account for these discrepancies. In this prospective study, mucosal mast cell counts were performed in Carnoy fixed, peroral jejunal biopsy specimens from patients with coeliac disease, both untreated and treated with a gluten-free diet; and from controls (mainly irritable bowel syndrome). Mean mucosal mast cell count in 27 control subjects was 146/mm2, SD 29. Significantly higher values were obtained in untreated coeliac disease (mean 243, SD 41, p less than 0.001) returning to the normal range in coeliacs treated with a gluten-free diet with normal jejunal biopsy morphology. In seven patients mucosal mast cell counts were performed in multiple jejunal biopsies, and these showed that mucosal mast cell distribution was not patchy. There was no evidence of degranulation of intestinal mucosal mast cells under the conditions of routine biopsy (overnight fast). An increase in mucosal mast cells in untreated coeliac disease may be one explanation for the high number of IgE positive stained cells in the intestinal mucosa that has been reported by some authors. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:6826106

Effect of methylmercury on the rat mast cell degranulation

NASA Astrophysics Data System (ADS)

Graevskaya, E. E.; Yasutake, A.; Aramai, R.; Rubin, A. B.

2003-05-01

Methylmercury is the well-known neurotoxicant as weil as a modulator of the immune system. We investigated the effects of MeHg on the rat mast cell degranulation induced by nonimmunological stimuli (the selective liberator of histamine, compound 48/80, and calcium ionophore A23187) both in vivo and in vitro. In 8, 12 and 15 days afterthe final administration of MeHg we observed the suppression of calcium ionophore A23187-and 48/80-induced histamine release, which enhanced with time. In experiments in vitro incubation of peritoneal mast cells with MeHg alone in the dose range 10^{-8} to 10^{-6} did not induce mast cell degranulation, however modified the activation of mast cells by compound 48/80, and calcium ionophore A23187. We observed activation of stimulated secretion by preliminary incubation with low dose of MeHg 10^{-8} M and inhibition by dose of MeHg 10^{-6} M. These results show that MeHg treatment can modify mast cell function in vivo and in vitro and provide insight into the understanding what role this cell has in the pathogenesis of Minamata disease-comlected disorders.

The chemokine receptor CCR1 is identified in mast cell-derived exosomes

PubMed Central

Liang, Yuting; Qiao, Longwei; Peng, Xia; Cui, Zelin; Yin, Yue; Liao, Huanjin; Jiang, Min; Li, Li

2018-01-01

Mast cells are important effector cells of the immune system, and mast cell-derived exosomes carrying RNAs play a role in immune regulation. However, the molecular function of mast cell-derived exosomes is currently unknown, and here, we identify differentially expressed genes (DEGs) in mast cells and exosomes. We isolated mast cells derived exosomes through differential centrifugation and screened the DEGs from mast cell-derived exosomes, using the GSE25330 array dataset downloaded from the Gene Expression Omnibus database. Biochemical pathways were analyzed by Gene ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway on the online tool DAVID. DEGs-associated protein-protein interaction networks (PPIs) were constructed using the STRING database and Cytoscape software. The genes identified from these bioinformatics analyses were verified by qRT-PCR and Western blot in mast cells and exosomes. We identified 2121 DEGs (843 up and 1278 down-regulated genes) in HMC-1 cell-derived exosomes and HMC-1 cells. The up-regulated DEGs were classified into two significant modules. The chemokine receptor CCR1 was screened as a hub gene and enriched in cytokine-mediated signaling pathway in module one. Seven genes, including CCR1, CD9, KIT, TGFBR1, TLR9, TPSAB1 and TPSB2 were screened and validated through qRT-PCR analysis. We have achieved a comprehensive view of the pivotal genes and pathways in mast cells and exosomes and identified CCR1 as a hub gene in mast cell-derived exosomes. Our results provide novel clues with respect to the biological processes through which mast cell-derived exosomes modulate immune responses. PMID:29511430

Mast cell migration to Th2 stimulated airway smooth muscle from asthmatics

PubMed Central

Sutcliffe, A; Kaur, D; Page, S; Woodman, L; Armour, C L; Baraket, M; Bradding, P; Hughes, J M; Brightling, C E

2006-01-01

Background Mast cell microlocalisation within the airway smooth muscle (ASM) bundle is an important determinant of the asthmatic phenotype. We hypothesised that mast cells migrate towards ASM in response to ASM derived chemokines. Methods Primary ASM cultures from subjects with and without asthma were stimulated with interleukin (IL)‐1β, IL‐4, and IL‐13 alone and in combination. Mast cell chemotaxis towards these ASM supernatants was investigated, and the chemotaxins mediating migration by using specific blocking antibodies for stem cell factor (SCF) and the chemokine receptors CCR3, CXCR1, 3 and 4 as well as the Gi inhibitor pertussis toxin and the tyrosine kinase inhibitor genistein were defined. The concentrations of CCL11, CXCL8, CXCL10, TGF‐β, and SCF in the supernatants were measured and the effect of non‐asthmatic ASM supernatants on the mast cell chemotactic activity of asthmatic ASM was examined. Results Human lung mast cells and HMC‐1 cells migrated towards Th2 stimulated ASM from asthmatics but not non‐asthmatics. Mast cell migration was mediated through the combined activation of CCR3 and CXCR1. CCL11 and CXCL8 expression by ASM increased markedly after stimulation, but was similar in those with and without asthma. ASM supernatants from non‐asthmatics inhibited mast cell migration towards the asthmatic ASM supernatant. Conclusion Th2 stimulated ASM from asthmatics is chemotactic for mast cells. Non‐asthmatic ASM releases a mediator or mediators that inhibit mast cell migration towards stimulated asthmatic ASM. Specifically targeting mast cell migration into the ASM bundle may provide a novel treatment for asthma. PMID:16601090

The chemokine receptor CCR1 is identified in mast cell-derived exosomes.

PubMed

Liang, Yuting; Qiao, Longwei; Peng, Xia; Cui, Zelin; Yin, Yue; Liao, Huanjin; Jiang, Min; Li, Li

2018-01-01

Mast cells are important effector cells of the immune system, and mast cell-derived exosomes carrying RNAs play a role in immune regulation. However, the molecular function of mast cell-derived exosomes is currently unknown, and here, we identify differentially expressed genes (DEGs) in mast cells and exosomes. We isolated mast cells derived exosomes through differential centrifugation and screened the DEGs from mast cell-derived exosomes, using the GSE25330 array dataset downloaded from the Gene Expression Omnibus database. Biochemical pathways were analyzed by Gene ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway on the online tool DAVID. DEGs-associated protein-protein interaction networks (PPIs) were constructed using the STRING database and Cytoscape software. The genes identified from these bioinformatics analyses were verified by qRT-PCR and Western blot in mast cells and exosomes. We identified 2121 DEGs (843 up and 1278 down-regulated genes) in HMC-1 cell-derived exosomes and HMC-1 cells. The up-regulated DEGs were classified into two significant modules. The chemokine receptor CCR1 was screened as a hub gene and enriched in cytokine-mediated signaling pathway in module one. Seven genes, including CCR1, CD9, KIT, TGFBR1, TLR9, TPSAB1 and TPSB2 were screened and validated through qRT-PCR analysis. We have achieved a comprehensive view of the pivotal genes and pathways in mast cells and exosomes and identified CCR1 as a hub gene in mast cell-derived exosomes. Our results provide novel clues with respect to the biological processes through which mast cell-derived exosomes modulate immune responses.

KSC-02pd0590

NASA Image and Video Library

2002-04-29

KENNEDY SPACE CENTER, FLA. -- Space Shuttle Endeavour rests on Launch Pad 39A after rollout from the Vehicle Assembly Building. The Shuttle comprises the orbiter, in front, and the taller orange external tank behind it flanked by twin solid rocket boosters. The Shuttle sits on the Mobile Launcher Platform that straddles the flame trench below. On either side of Endeavour's tail and main engines are the tail service masts that support the fluid,, gas and electrical requirements of the orbiter's liquid oxyen and liquid hydrogen aft T-0 umbilicals. At left is the open Rotating Service Structure and the Fixed Service Structure to its right, with its 80-foot lightning mast on top. Mission STS-111 is designated UF-2, the 14th assembly flight to the International Space Station. Endeavour's payload includes the Multi-Purpose Logistics Module Leonardo and Mobile Base System. The mission also will swap resident crews on the Station, carrying the Expedition 5 crew and returning to Earth Expedition 4. Liftoff of Endeavour is scheduled between 4 and 8 p.m. May 30, 2002

Expression of Tocopherol-Associated Protein in Mast Cells

PubMed Central

Ikeda, Teruo; Murakami, Masaru; Funaba, Masayuki

2004-01-01

Tocopherol-associated protein (TAP) was expressed in mouse mast cells. TAP was predominantly localized in the cytoplasm, and the subcellular localization was not changed by α-tocopherol. The results suggest that the physiological role of TAP in mast cells is not regulation of tocopherol function but an as-yet-unidentified activity. PMID:15539527

Type 1 diabetes in NOD mice unaffected by mast cell deficiency.

PubMed

Gutierrez, Dario A; Fu, Wenxian; Schonefeldt, Susann; Feyerabend, Thorsten B; Ortiz-Lopez, Adriana; Lampi, Yulia; Liston, Adrian; Mathis, Diane; Rodewald, Hans-Reimer

2014-11-01

Mast cells have been invoked as important players in immune responses associated with autoimmune diseases. Based on in vitro studies, or in vivo through the use of Kit mutant mice, mast cells have been suggested to play immunological roles in direct antigen presentation to both CD4(+) and CD8(+) T cells, in the regulation of T-cell and dendritic cell migration to lymph nodes, and in Th1 versus Th2 polarization, all of which could significantly impact the immune response against self-antigens in autoimmune disease, including type 1 diabetes (T1D). Until now, the role of mast cells in the onset and incidence of T1D has only been indirectly tested through the use of low-specificity mast cell inhibitors and activators, and published studies reported contrasting results. Our three laboratories have generated independently two strains of mast cell-deficient nonobese diabetic (NOD) mice, NOD.Cpa3(Cre/+) (Heidelberg) and NOD.Kit(W-sh/W-sh) (Leuven and Boston), to address the effects of mast cell deficiency on the development of T1D in the NOD strain. Our collective data demonstrate that both incidence and progression of T1D in NOD mice are independent of mast cells. Moreover, analysis of pancreatic lymph node cells indicated that lack of mast cells has no discernible effect on the autoimmune response, which involves both innate and adaptive immune components. Our results demonstrate that mast cells are not involved in T1D in the NOD strain, making their role in this process nonessential and excluding them as potential therapeutic targets. © 2014 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Increased Bone Mass in Female Mice Lacking Mast Cell Chymase

PubMed Central

Lind, Thomas; Gustafson, Ann-Marie; Calounova, Gabriela; Hu, Lijuan; Rasmusson, Annica; Jonsson, Kenneth B.; Wernersson, Sara; Åbrink, Magnus; Andersson, Göran; Larsson, Sune; Melhus, Håkan; Pejler, Gunnar

2016-01-01

Here we addressed the potential impact of chymase, a mast-cell restricted protease, on mouse bone phenotype. We show that female mice lacking the chymase Mcpt4 acquired a persistent expansion of diaphyseal bone in comparison with wild type controls, reaching a 15% larger diaphyseal cross sectional area at 12 months of age. Mcpt4-/- mice also showed increased levels of a bone anabolic serum marker and higher periosteal bone formation rate. However, they were not protected from experimental osteoporosis, suggesting that chymase regulates normal bone homeostasis rather than the course of osteoporosis. Further, the absence of Mcpt4 resulted in age-dependent upregulation of numerous genes important for bone formation but no effects on osteoclast activity. In spite of the latter, Mcpt4-/- bones had increased cortical porosity and reduced endocortical mineralization. Mast cells were found periosteally and, notably, bone-proximal mast cells in Mcpt4-/- mice were degranulated to a larger extent than in wild type mice. Hence, chymase regulates degranulation of bone mast cells, which could affect the release of mast cell-derived factors influencing bone remodelling. Together, these findings reveal a functional impact of mast cell chymase on bone. Further studies exploring the possibility of using chymase inhibitors as a strategy to increase bone volume may be warranted. PMID:27936149

Quantification of mast cells in different stages of periodontal disease.

PubMed

Marjanović, Dragan; Andjelković, Zlatibor; Brkić, Zlata; Videnović, Goran; Šehalić, Meliha; Matvjenko, Vladimir; Leštarević, Snežana; Djordjević, Nadica

2016-05-01

Mast cells are mononuclear cells originating from bone marrow. They produce various biologically active substances, which allow them to actively participate in immune and inflammatory processes associated with periodontal disease. The study focused on distribution and density of mast cells in healthy gingiva as well as in different stages of periodontal disease. The material used for this purpose was gingival biopsies taken from 96 patients classified into 4 groups: healthy gingiva, gingivitis, initial and severe periodontal disease. Toluidine blue staining according to Spicer was utilized for identifying mast cells. Basing on our study, the density of mast cells in the gingival tissue increases with the progression of the infection, which means they are more numerous in gingivitis compared to healthy gingiva, as well as in periodontal disease compared to gingivitis. Increase in the number of mast cells in the infected gingiva can be correlated with an increased influx of inflammatory cells from blood circulation into the gingival stroma, as well as with the collagen lysis, since these cells produce substances with collagenolytic potential. Based on the distribution of mast cells, it could be concluded that in the evolution of periodontal disease there are significant dynamic alterations in migration and localization of these cells.

Seasonal Mast Availability for Wildlife in the Piedmont Region of Georgia

Treesearch

John W. Edwards; David C. Guynn; Susan C. Loeb

1993-01-01

We measured mast production by traditional and buffer species for 2 years on the Piedmont National Wildlife Refuge in Georgia. Our objectives were to determine how these two types varied on a seasonal, annual, and habitat basis. Mast from buffer species was more frequent and diverse than that from traditional mast producers. Our findings suggest that although...

Mast cells mediate the immune suppression induced by dermal exposure to JP-8 jet fuel.

PubMed

Limón-Flores, Alberto Y; Chacón-Salinas, Rommel; Ramos, Gerardo; Ullrich, Stephen E

2009-11-01

Applying jet propulsion-8 (JP-8) jet fuel to the skin of mice induces immune suppression. Applying JP-8 to the skin of mice suppresses T-cell-mediated immune reactions including, contact hypersensitivity (CHS) delayed-type hypersensitivity and T-cell proliferation. Because dermal mast cells play an important immune regulatory role in vivo, we tested the hypothesis that mast cells mediate jet fuel-induced immune suppression. When we applied JP-8 to the skin of mast cell deficient mice CHS was not suppressed. Reconstituting mast cell deficient mice with wild-type bone marrow derived mast cells (mast cell "knock-in mice") restored JP-8-induced immune suppression. When, however, mast cells from prostaglandin E(2) (PGE(2))-deficient mice were used, the ability of JP-8 to suppress CHS was not restored, indicating that mast cell-derived PGE(2) was activating immune suppression. Examining the density of mast cells in the skin and lymph nodes of JP-8-treated mice indicated that jet fuel treatment caused an initial increase in mast cell density in the skin, followed by increased numbers of mast cells in the subcutaneous space and then in draining lymph nodes. Applying JP-8 to the skin increased mast cell expression of CXCR4, and increased the expression of CXCL12 by draining lymph node cells. Because CXCL12 is a chemoattractant for CXCR4+ mast cells, we treated JP-8-treated mice with AMD3100, a CXCR4 antagonist. AMD3100 blocked the mobilization of mast cells to the draining lymph node and inhibited JP-8-induced immune suppression. Our findings demonstrate the importance of mast cells in mediating jet fuel-induced immune suppression.

Anaphylaxis as a clinical manifestation of clonal mast cell disorders.

PubMed

Matito, A; Alvarez-Twose, I; Morgado, J M; Sánchez-Muñoz, L; Orfao, A; Escribano, L

2014-08-01

Clonal mast cell disorders comprise a heterogeneous group of disorders characterized by the presence of gain of function KIT mutations and a constitutively altered activation-associated mast cell immunophenotype frequently associated with clinical manifestations related to the release of mast cells mediators. These disorders do not always fulfil the World Health Organization (WHO)-proposed criteria for mastocytosis, particularly when low-sensitive diagnostic approaches are performed. Anaphylaxis is a frequent presentation of clonal mast cell disorders, particularly in mastocytosis patients without typical skin lesions. The presence of cardiovascular symptoms, e.g., hypotension, occurring after a hymenoptera sting or spontaneously in the absence of cutaneous manifestations such as urticaria is characteristic and differs from the presentation of anaphylaxis in the general population without mastocytosis.

MAST magnetic diagnostics

NASA Astrophysics Data System (ADS)

Edlington, T.; Martin, R.; Pinfold, T.

2001-01-01

The mega-ampere spherical tokamak (MAST) experiment is a new, large, low aspect ratio device (R=0.7-0.8 m, a=0.5-0.65 m, maximum BT˜0.63 T at R=0.7 m) operating its first experimental physics campaign. Designed to study a wide variety of plasma shapes with up to 2 MA of plasma current with an aspect ratio down to 1.3, the poloidal field (PF) coils used for plasma formation, equilibrium and shaping are inside the main vacuum vessel. For plasma control and to investigate a wide range of plasma phenomena, an extensive set of magnetic diagnostics have been installed inside the vacuum vessel. More than 600 vacuum compatible, bakeable diagnostic coils are configured in a number of discrete arrays close to the plasma edge with about half the coils installed behind the graphite armour tiles covering the center column. The coil arrays measure the toroidal and poloidal variation in the equilibrium field and its high frequency fluctuating components. Internal coils also measure currents in the PF coils, plasma current, stored energy and induced currents in the mechanical support structures of the coils and graphite armour tiles. The latter measurements are particularly important when halo currents are induced following a plasma termination, for example, when the plasma becomes vertically unstable. The article describes the MAST magnetic diagnostic coil set and their calibration. The way in which coil signals are used to control the plasma equilibrium is described and data from the first MAST experimental campaign presented. These coil data are used as input to the code EFIT [L. Lao et al., Nucl. Fusion 25, 1611 (1985)], for measurement of halo currents in the vacuum vessel structure and for measurements of the structure of magnetic field fluctuations near the plasma edge.

Mast Cells Mediate the Immune Suppression Induced by Dermal Exposure to JP-8 Jet Fuel

PubMed Central

Limón-Flores, Alberto Y.; Chacón-Salinas, Rommel; Ramos, Gerardo; Ullrich, Stephen E.

2009-01-01

Applying jet propulsion-8 (JP-8) jet fuel to the skin of mice induces immune suppression. Applying JP-8 to the skin of mice suppresses T-cell–mediated immune reactions including, contact hypersensitivity (CHS) delayed-type hypersensitivity and T-cell proliferation. Because dermal mast cells play an important immune regulatory role in vivo, we tested the hypothesis that mast cells mediate jet fuel–induced immune suppression. When we applied JP-8 to the skin of mast cell deficient mice CHS was not suppressed. Reconstituting mast cell deficient mice with wild-type bone marrow derived mast cells (mast cell “knock-in mice”) restored JP-8–induced immune suppression. When, however, mast cells from prostaglandin E2 (PGE2)–deficient mice were used, the ability of JP-8 to suppress CHS was not restored, indicating that mast cell–derived PGE2 was activating immune suppression. Examining the density of mast cells in the skin and lymph nodes of JP-8-treated mice indicated that jet fuel treatment caused an initial increase in mast cell density in the skin, followed by increased numbers of mast cells in the subcutaneous space and then in draining lymph nodes. Applying JP-8 to the skin increased mast cell expression of CXCR4, and increased the expression of CXCL12 by draining lymph node cells. Because CXCL12 is a chemoattractant for CXCR4+ mast cells, we treated JP-8-treated mice with AMD3100, a CXCR4 antagonist. AMD3100 blocked the mobilization of mast cells to the draining lymph node and inhibited JP-8–induced immune suppression. Our findings demonstrate the importance of mast cells in mediating jet fuel–induced immune suppression. PMID:19726579

Idiopathic Mast Cell Activation Syndrome With Associated Salicylate Intolerance.

PubMed

Rechenauer, Tobias; Raithel, Martin; Götze, Thomas; Siebenlist, Gregor; Rückel, Aline; Baenkler, Hanns-Wolf; Hartmann, Arndt; Haller, Florian; Hoerning, André

2018-01-01

Idiopathic mast cell activation syndrome can be a rare cause for chronic abdominal pain in children. It remains a diagnosis by exclusion that can be particularly challenging due to the vast variety of possible clinical manifestations. We present a 13-year-old boy who suffered from a multitude of unspecific complaints over a long period of time. In this case, an assessment of mast cell-derived metabolites and immunohistochemical analysis of bioptic specimen was worthwhile. After ruling out, primary (oncologic) and secondary causes for mast cell activation, pharmacologic treatment adapted to the patient's salicylate intolerance resulted in a major relief of symptoms.

Evaluation of mast cells in periapical cysts, dentigerous cysts, and keratocystic odontogenic tumors.

PubMed

de Noronha Santos Netto, Juliana; Pires, Fábio Ramôa; da Fonseca, Eliene Carvalho; Silva, Licínio Esmeraldo; de Queiroz Chaves Lourenço, Simone

2012-09-01

Several cell types are associated with the development of cystic and tumoral odontogenic lesions. Among inflammatory cells, mast cells can be associated with their pathogenesis. The aim of this study was to analyze mast cells in periapical cysts, dentigerous cysts, and keratocystic odontogenic tumors. Tissue sections were submitted to toluidine blue staining and immunohistochemistry with antibody anti-tryptase (clone G3). Mast cells were quantitated using Image-Pro Plus software to obtain the mean number of mast cells in three regions: epithelial, superficial portion of the fibrous wall and deep portion of the fibrous wall from 20 periapical cysts, 20 dentigerous cysts (six non-inflamed and 14 inflamed) and 20 keratocystic odontogenic tumors (four non-inflamed and 16 inflamed). The mean number of mast cells detected per lesion by immunohistochemistry (4.1) was higher than by histochemistry (1.5) (P<0.0001). Inflamed dentigerous cysts and keratocystic odontogenic tumors showed a higher mean number of mast cells than non-inflamed lesions in all regions. The deep region from all cysts showed the highest mean number of degranulated mast cells, except for non-inflamed keratocystic odontogenic tumors analyzed by immunohistochemistry. Immunohistochemical staining detected higher number of mast cells than histochemistry. The higher number of mast cells observed in inflamed lesions could indicate the participation of these cells in the inflammatory response in odontogenic lesions. The prevalence of degranulated mast cells in the deep region suggests intense activity of these cells, possibly related to growth of cystic lesions. © 2012 John Wiley & Sons A/S.

Breeding system and pollen limitation in the masting tree Sorbus aucuparia L. (Rosaceae) in the NW Iberian Peninsula

NASA Astrophysics Data System (ADS)

Pías, Beatriz; Guitián, Pablo

2006-01-01

Mast seeding or masting is the supra-annual periodic production of a large number of seeds by long-lived plants. It has been suggested that this may be a strategy to increase pollination efficiency. Sorbus aucuparia is a masting tree typically showing rather low fruit set, though with some variation among years and populations, together with marked among-year variation in flower and fruit production. Here we report a study of the reproductive biology and insect-visitor spectrum of S. aucuparia in the NW Iberian Peninsula. Results obtained over a 4-year period indicate marked self-incompatibility, so that fruit set is strongly dependent on pollinator service. Nevertheless, fruit and seed set were not limited by pollen supply in any of the years of study, since fruit and seed set after manual cross-pollination were no higher than after natural pollination. Inflorescences were visited by diverse insect species. There was no significant correlation between fruit set and insect visit frequency. Taken together, these findings indicate that the rather low fruit and seed sets observed in this species, and the spatiotemporal variation in these parameters, must be attributed to other factors, such as abiotic resource availability. We conclude that masting in S. aucuparia is probably not a strategy for increasing pollination efficiency.

Detection of mast cell secretion by using surface enhanced Raman scattering

NASA Astrophysics Data System (ADS)

Li, Juan; Li, Ren; Zheng, Liqin; Wang, Yuhua; Xie, Shusen; Lin, Juqiang

2016-10-01

Acupuncture can cause a remarkable increase in degranulation of the mast cells, which has attracted the interest of researchers since the 1980s. Surface-enhanced Raman scattering (SERS) could obtain biochemical information with high sensitivity and specificity. In this study, SERS was used to detect the degree of degranulation of mast cells according to different incubate time. Mast cells was incubated with culture medium for 0 h, 12 h and 24 h, then centrifuge the culture medium, decant the supernatant, and discard the mast cell. SERS was performed to obtain the biochemical fingerprinting signatures of the centrifuged medium. The spectra data are then analyzed by spectral peaks attribution and the principal component analysis (PCA). The measured Raman spectra of the two groups were separated well by PCA. It indicated that mast cells had secreted some substances into cultured medium though degranulation did not happen.

Lysophosphatidic acid triggers mast cell-driven atherosclerotic plaque destabilization by increasing vascular inflammation[S

PubMed Central

Bot, Martine; de Jager, Saskia C. A.; MacAleese, Luke; Lagraauw, H. Maxime; van Berkel, Theo J. C.; Quax, Paul H. A.; Kuiper, Johan; Heeren, Ron M. A.; Biessen, Erik A. L.; Bot, Ilze

2013-01-01

Lysophosphatidic acid (LPA), a bioactive lysophospholipid, accumulates in the atherosclerotic plaque. It has the capacity to activate mast cells, which potentially exacerbates plaque progression. In this study, we thus aimed to investigate whether LPA contributes to plaque destabilization by modulating mast cell function. We here show by an imaging mass spectrometry approach that several LPA species are present in atherosclerotic plaques. Subsequently, we demonstrate that LPA is a potent mast cell activator which, unlike other triggers, favors release of tryptase. Local perivascular administration of LPA to an atherosclerotic carotid artery segment increases the activation status of perivascular mast cells and promotes intraplaque hemorrhage and macrophage recruitment without impacting plaque cell apoptosis. The mast cell stabilizer cromolyn could prevent intraplaque hemorrhage elicited by LPA-mediated mast cell activation. Finally, the involvement of mast cells in these events was further emphasized by the lack of effect of perivascular LPA administration in mast cell deficient animals. We demonstrate that increased accumulation of LPA in plaques induces perivascular mast cell activation and in this way contributes to plaque destabilization in vivo. This study points to local LPA availability as an important factor in atherosclerotic plaque stability. PMID:23396975

Inhibitory effects of low molecular weight heparin on mediator release by mast cells: preferential inhibition of cytokine production and mast cell-dependent cutaneous inflammation

PubMed Central

BARAM, D; RASHKOVSKY, M; HERSHKOVIZ, R; DRUCKER, I; RESHEF, T; BEN-SHITRIT, S; MEKORI, Y A

1997-01-01

There has been substantial evidence that suggests that heparin may modulate various aspects of immune function and inflammation in addition to its well known anticoagulant activity. In this regard heparin was found to suppress cell-mediated immune responses or asthmatic reactions to allergen challenge. In the present study we analyse the effects of low molecular weight heparin (LMWH) on mast cell degranulation and cytokine production in vitro and on the elicitation of IgE-mediated mast cell-dependent late cutaneous allergic inflammation in vivo. We have established that LMWH preferentially inhibited tumour necrosis factor-alpha (TNF-α) and IL-4 production without having any significant effect on mast cell degranulation. These effects have been observed in mast cells derived from three different origins that were activated by either immunological or non-immunological stimuli. We have shown that there is inhibition of TNF-α production (and not neutralization of activity), as elimination of the drug after a short preincubation and addition of LMWH to rTNF-α had no effect on TNF-α-mediated cytotoxic activity. These results were also confirmed by ELISA. In vivo, s.c. injection of the LMWH inhibited the leucocyte infiltration associated with the late cutaneous response which followed passive cutaneous anaphylaxis (PCA) reaction, without affecting mast cell numbers or degranulation. These data suggest that LMWH may have an inhibitory role in mast cell-mediated allergic inflammation, and thus might be considered as a possible therapeutic modality. PMID:9409655

Kefiran suppresses antigen-induced mast cell activation.

PubMed

Furuno, Tadahide; Nakanishi, Mamoru

2012-01-01

Kefir is a traditional fermented milk beverage produced by kefir grains in the Caucasian countries. Kefiran produced by Lactobacillus kefiranofaciens in kefir grains is an exopolysaccharide having a repeating structure with glucose and galactose residues in the chain sequence and has been suggested to exert many health-promoting effects such as immunomodulatory, hypotensive, hypocholesterolemic activities. Here we investigated the effects of kefiran on mast cell activation induced by antigen. Pretreatment with kefiran significantly inhibited antigen-induced Ca(2+) mobilization, degranulation, and tumor necrosis factor-α production in bone marrow-derived mast cells (BMMCs) in a dose-dependent manner. The phosphorylation of Akt, glycogen synthase kinase 3β, and extracellular signal-regulated kinases (ERKs) after antigen stimulation was also suppressed by pretreatment of BMMCs with kefiran. These findings indicate that kefiran suppresses mast cell degranulation and cytokine production by inhibiting the Akt and ERKs pathways, suggesting an anti-inflammatory effect for kefiran.

A Dog Is a Doctor's Best Friend: The Use of a Service Dog as a Perioperative Assistant.

PubMed

Tew, Shannon; Taicher, Brad M

2016-01-01

Service dogs are beneficial in providing assistance to people with multiple types of disabilities and medical disorders including visual impairment, physical disabilities, seizure disorders, diabetes, and mental illness. Some service animals have been trained as a screening tool for cancer. We review a case involving a 6-year-old female with a history of mast cell mediator release and immediate hypersensitivity due to the urticaria pigmentosa variant of cutaneous mastocytosis who underwent a cystourethroscopy. Her service dog, JJ, who would alert to mast cell mediator release, was used throughout the perioperative course as a means of anxiolysis and comfort and to monitor for mast cell mediator release. This case presents an example of a service dog used in a family-care model in the field of anesthesiology and provides a unique example of using a service dog as an additional monitor to alert the care team for impending mast cell mediator release.

A Dog Is a Doctor's Best Friend: The Use of a Service Dog as a Perioperative Assistant

PubMed Central

Tew, Shannon

2016-01-01

Service dogs are beneficial in providing assistance to people with multiple types of disabilities and medical disorders including visual impairment, physical disabilities, seizure disorders, diabetes, and mental illness. Some service animals have been trained as a screening tool for cancer. We review a case involving a 6-year-old female with a history of mast cell mediator release and immediate hypersensitivity due to the urticaria pigmentosa variant of cutaneous mastocytosis who underwent a cystourethroscopy. Her service dog, JJ, who would alert to mast cell mediator release, was used throughout the perioperative course as a means of anxiolysis and comfort and to monitor for mast cell mediator release. This case presents an example of a service dog used in a family-care model in the field of anesthesiology and provides a unique example of using a service dog as an additional monitor to alert the care team for impending mast cell mediator release. PMID:27843665

The development of human mast cells. An historical reappraisal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ribatti, Domenico, E-mail: domenico.ribatti@uniba.it

2016-03-15

The understanding of mast cell (MC) differentiation is derived mainly from in vitro studies of different stages of stem and progenitor cells. The hematopoietic lineage development of human MCs is unique compared to other myeloid-derived cells. Human MCs originate from CD34{sup +}/CD117{sup +}/CD13{sup +}multipotent hematopoietic progenitors, which undergo transendothelial recruitment into peripheral tissues, where they complete differentiation. Stem cell factor (SCF) is a major chemotactic factor for MCs and their progenitors. SCF also elicits cell-cell and cell-substratum adhesion, facilitates the proliferation, and sustains the survival, differentiation, and maturation, of MCs. Because MC maturation is influenced by local microenvironmental factors, differentmore » MC phenotypes can develop in different tissues and organs. - Highlights: • Human mast cells originate from CD34/CD117/CD13 positive multipotent hematopoietic progenitors. • Stem cell factor is a major chemotactic factor for mast cells and their progenitors. • Different mast cell phenotypes can develop in different tissues and organs.« less

Comparison of Mast Cells Count in Odontogenic Cysts Using Histochemical Staining.

PubMed

Rajabi-Moghaddam, Mahdieh; Abbaszadeh-Bidokhty, Hamid; Bijani, Ali

2015-01-01

Odontogenic cysts are among the most frequent destructive lesions of jaws which their pathogenesis and growth mechanism are not cleared. With respect to different roles of mast cells, they may play a role in the pathogenesis and growth of odontogenic cysts. The aim of present study was to evaluate mast cells in the most common odontogenic cyst. Thirty paraffin-embedded tissue blocks including 10 radicular cysts, 10 dentigerous cysts and 10 odontogenic keratocysts were used and 5 micron sections stained with toluidine blue and observed by light microscope under ×400 magnification to evaluate mast cells within these cysts. For each case, 5 high-power field areas, selected from hot-spot areas, were considered and each area divided into 3 zones: intra-epithelial zone, sub-epithelial zone and deep zone. Most of the studied cyst showed presence of mast cells. There was not any significant difference in mast cell count between studied cysts ( P -values > 0.05).With respect to intra-epithelial, sub-epithelial and deep zones, there was not any significant difference between three studied cysts. There was not any significant difference between sub-epithelial zone and deep zone within each of these cysts. There was only significant difference between intra-epithelial zone and sub-epithelial zone within dentigerous cysts and odontogenic keratocysts ( P -value < 0.05). Prevalence of mast cells in fibrous wall of odontogenic cysts suggests their activity in these cysts. Mast cells may not be directly involved in the pathogenesis of odontogenic keratocysts.

In Vitro Desensitization of Human Skin Mast Cells

PubMed Central

Zhao, Wei; Gomez, Gregorio; Macey, Matthew; Kepley, Christopher L.

2013-01-01

Desensitization is a clinical procedure whereby incremental doses of a drug are administered over several hours to a sensitive patient until a therapeutic dose and clinical tolerance are achieved. Clinical tolerance may occur in part by attenuating the mast cell response. In the present study, primary human skin mast cells were used to establish and characterize an in vitro model of desensitization. Mast cells in culture were armed with allergen-specific (4-hydroxy-3-nitro-phenylacety and Der p2) and non-specific IgE antibodies, and then desensitized by incremental exposures to 4-hydroxy-3-nitrophenylacety-BSA. This desensitization procedure abrogated the subsequent degranulation response to the desensitizing allergen, to an unrelated allergen, and to IgG anti-FcεRI, but not to C5a, substance P, compound 48/80, and calcium ionophore. Desensitized cells regained their FcεRI-dependent degranulation capability by 24–48 h after free allergen had been removed. Therefore, sensitized human skin mast cells are reversibly desensitized in vitro by exposure to incremental doses of that allergen, which also cross-desensitizes them to an unrelated allergen. PMID:22009002

Promotion of mouse fibroblast collagen gene expression by mast cells stimulated via the Fc epsilon RI. Role for mast cell-derived transforming growth factor beta and tumor necrosis factor alpha

PubMed Central

1994-01-01

Chronic allergic diseases and other disorders associated with mast cell activation can also be associated with tissue fibrosis, but a direct link between mast cell mediator release and fibroblast collagen gene expression has not been established. Using in situ hybridization, we show that the elicitation of an IgE-dependent passive cutaneous anaphylaxis (PCA) reaction in mice results in a transient, but marked augmentation of steady state levels of type alpha-1 (I) collagen mRNA in the dermis. While peak levels of collagen mRNA expression in the skin are observed 16-24 h after mast cell activation, substantial numbers of dermal cells are strongly positive for collagen mRNA at 1 and 2 h after antigen challenge, before circulating inflammatory cells are recruited into the tissues. Furthermore, experiments in mast cell- reconstituted or genetically mast cell-deficient WBB6F1-W/Wv mice demonstrate that the increased expression of collagen mRNA at sites of PCA reactions is entirely mast cell dependent. In vitro studies show that the supernatants of mouse serosal mast cells activated via the Fc epsilon RI markedly increase type alpha-1 (I) collagen mRNA levels in mouse embryonic skin fibroblasts, and also upregulate collagen secretion by these cells. The ability of mast cell supernatants to induce increased steady state levels of collagen mRNA in mouse skin fibroblasts is markedly diminished by absorption with antibodies specific for either of two mast cell-derived cytokines, transforming growth factor beta (TGF-beta 1) or tumor necrosis factor alpha (TNF- alpha), and is eliminated entirely by absorption with antibodies against both cytokines. Taken together, these findings demonstrate that IgE-dependent mouse mast cell activation can induce a transient and marked increase in steady state levels of type alpha-1 (I) collagen mRNA in dermal fibroblasts and that mast cell-derived TGF-beta 1 and TNF-alpha importantly contribute to this effect. PMID:7964480

Mathematics and Science Teaching for English Learners (MAST-EL) Partnership: A Relationship among Elementary School Teachers, Preservice Teachers, Principals, Coaches, and College Faculty

ERIC Educational Resources Information Center

Harding-DeKam, Jenni L.; Reinsvold, Lori; Olmos, Antonio; Song, Youngjin; Franklin, Elizabeth; Enríquez, Mariana; Higgins, Teresa

2014-01-01

The MAST-EL University and School Partnership supports a strategic infrastructure for preparing preservice and in-service teachers ensuring high quality mathematics and science instruction for English learners (ELs). The partnership in its second year consists of thirty-two in-service elementary teachers, three instructional coaches, thirty…

Equine Airway Mast Cells are Sensitive to Cell Death Induced by Lysosomotropic Agents.

PubMed

Wernersson, S; Riihimäki, M; Pejler, G; Waern, I

2017-01-01

Mast cells are known for their detrimental effects in various inflammatory conditions. Regimens that induce selective mast cell apoptosis may therefore be of therapeutic significance. Earlier studies have demonstrated that murine- and human-cultured mast cells are highly sensitive to apoptosis induced by the lysosomotropic agent LeuLeuOMe (LLME). However, the efficacy of lysosomotropic agents for inducing apoptosis of in vivo-derived airway mast cells and the impact on mast cells in other species have not been assessed. Here we addressed whether lysosomotropic agents can induce cell death of equine in vivo-derived mast cells. Bronchoalveolar lavage (BAL) fluids from horses were incubated with LLME at 15-100 μm for up to 48 h. The overall cell viability was unaffected by 15 μm LLME up to 48 h, whereas a relatively modest drop in total cell counts (~30%) was seen at the highest LLME dose used. In contrast to the relatively low effect on total cell counts, LLME efficiently and dose dependently reduced the number of mast cells in BAL fluids, with an almost complete depletion (96%) of mast cells after 24 h of incubation with 100 μm LLME. A significant but less dramatic reduction (up to ~45%) of lymphocytes was also seen, whereas macrophages and neutrophils were essentially resistant. The appearance of apoptotic bodies suggested a mechanism involving apoptosis rather than necrosis. These findings suggest that equine airway mast cells are highly sensitive to lysosomotropic agents. Possibly, lysosomotropic agents could be of therapeutic value to treat disorders involving harmful accumulation of mast cells in the airways. © 2016 The Foundation for the Scandinavian Journal of Immunology.

Hydrocortisone and dexamethasone dose-dependently stabilize mast cells derived from rat peritoneum.

PubMed

Mori, Tomohiro; Abe, Nozomu; Saito, Kazutomo; Toyama, Hiroaki; Endo, Yasuhiro; Ejima, Yutaka; Yamauchi, Masanori; Goto, Mariko; Mushiake, Hajime; Kazama, Itsuro

2016-12-01

Besides their anti-inflammatory properties, corticosteroid drugs exert anti-allergic effects. Exocytosis of mast cells is electrophysiologically detected as the increase in the whole-cell membrane capacitance (Cm). Therefore, the lack of such increase after exposure to the drugs suggests their mast cell-stabilizing effects. We examined the effects of 1, 10, 100 and 200μM hydrocortisone or dexamethasone on the degranulation from rat peritoneal mast cells. Employing the whole-cell patch-clamp recording technique, we also tested their effects on the Cm during exocytosis. At relatively lower concentrations (1, 10μM), both hydrocortisone and dexamethasone did not significantly affect the degranulation from mast cells and the increase in the Cm induced by GTP-γ-S. Nevertheless, at higher doses (100, 200μM), these drugs inhibited the degranulation from mast cells and markedly suppressed the GTP-γ-S-induced increase in the Cm. Our results provided electrophysiological evidence for the first time that corticosteroid drugs, such as hydrocortisone and dexamethasone, inhibited the exocytotic process of mast cells in a dose-dependent manner. The mast cell-stabilizing effects of these drugs may be attributable to their "non-genomic" action, by which they exert rapid anti-allergic effects. Copyright © 2016. Published by Elsevier Urban & Partner Sp. z o.o.

Developmental changes of mast cell populations in the cerebral meninges of the rat.

PubMed

Michaloudi, Helen; Batzios, Christos; Chiotelli, Maria; Papadopoulos, Georgios C

2007-10-01

It is known that both the dura and the pia mater attract and support the differentiation of mast cells. The present study shows that unevenly distributed mast cells in the cerebral meninges of the rat can be found in perivascular sites and vessel ramification points, but can also be unrelated to the meningeal vasculature. It also documents changes in the number, localization and staining preferences of the mast cells in the two meninges of the developing and mature rat brain. Quantitative examination of all types of histochemically differentiated meningeal mast cells reveals no major (although some exist) differences between right and left side subpopulations, but strongly suggests a different origin and fate of the dural and the pial mast cells. The number of dural mast cells, already high from postnatal day 0, although declining from postnatal day 21 onwards, remains conspicuous up to postnatal day 180. In contrast, pial mast cells are comparatively very few in the first day of the postnatal life, and despite a transient significant increase in the following two weeks, they reach almost zero levels from postnatal day 21.

Multiple co morbid conditions in patient with Mast Cell Activation Syndrome

DTIC Science & Technology

2017-10-26

conditions in patient \\\\·ith Mast Cell Activation Syndron1e Sb. GRANT NUMBER Sc. PROGRAM.ELEMENT NUMBER 6. AUTHOR(S) Sd. PROJECT NUMBER Maj Sofia...13. SUPPLEMENTARY NOTES 14. ABSTRACT Multiple co-n1orhid conditions in patient \\Vith Mast Cell Activation Syndrotne Sofia M. Szari.MD. and James...Defense. !NTR()D{JCT!ON: Mast cell activation disorders {MCAD) have been associated \\Vilh Connective Tissue Disorders (CTD) and orthostatic

Suppression of Brain Mast Cells Degranulation Inhibits Microglial Activation and Central Nervous System Inflammation.

PubMed

Dong, Hongquan; Zhang, Xiang; Wang, Yiming; Zhou, Xiqiao; Qian, Yanning; Zhang, Shu

2017-03-01

Brain inflammation has a critical role in the pathophysiology of brain diseases. Microglia, the resident immune cells in the brain, play an important role in brain inflammation, while brain mast cells are the "first responder" in the injury rather than microglia. Functional aspects of mast cell-microglia interactions remain poorly understood. Our results demonstrated that site-directed injection of the "mast cell degranulator" compound 48/80 (C48/80) in the hypothalamus induced mast cell degranulation, microglial activation, and inflammatory factor production, which initiated the acute brain inflammatory response. "Mast cell stabilizer" disodium cromoglycate (cromolyn) inhibited this effect, including decrease of inflammatory cytokines, reduced microglial activation, inhibition of MAPK and AKT pathways, and repression of protein expression of histamine receptor 1 (H 1 R), histamine receptor 4 (H 4 R), protease-activated receptor 2 (PAR2), and toll-like receptor 4 (TLR4) in microglia. We also demonstrated that C48/80 had no effect on microglial activation in mast cell-deficient Kit W-sh/W-sh mice. These results implicate that activated brain mast cells trigger microglial activation and stabilization of mast cell inhibits microglial activation-induced central nervous system (CNS) inflammation. Interactions between mast cells and microglia could constitute a new and unique therapeutic target for CNS immune inflammation-related diseases.

Dengue Virus Infection of Mast Cells Triggers Endothelial Cell Activation ▿

PubMed Central

Brown, Michael G.; Hermann, Laura L.; Issekutz, Andrew C.; Marshall, Jean S.; Rowter, Derek; Al-Afif, Ayham; Anderson, Robert

2011-01-01

Vascular perturbation is a hallmark of severe forms of dengue disease. We show here that antibody-enhanced dengue virus infection of primary human cord blood-derived mast cells (CBMCs) and the human mast cell-like line HMC-1 results in the release of factor(s) which activate human endothelial cells, as evidenced by increased expression of the adhesion molecules ICAM-1 and VCAM-1. Endothelial cell activation was prevented by pretreatment of mast cell-derived supernatants with a tumor necrosis factor (TNF)-specific blocking antibody, thus identifying TNF as the endothelial cell-activating factor. Our findings suggest that mast cells may represent an important source of TNF, promoting vascular endothelial perturbation following antibody-enhanced dengue virus infection. PMID:21068256

The Mast Cell, Contact, and Coagulation System Connection in Anaphylaxis

PubMed Central

Guilarte, Mar; Sala-Cunill, Anna; Luengo, Olga; Labrador-Horrillo, Moisés; Cardona, Victoria

2017-01-01

Anaphylaxis is the most severe form of allergic reaction, resulting from the effect of mediators and chemotactic substances released by activated cells. Mast cells and basophils are considered key players in IgE-mediated human anaphylaxis. Beyond IgE-mediated activation of mast cells/basophils, further mechanisms are involved in the occurrence of anaphylaxis. New insights into the potential relevance of pathways other than mast cell and basophil degranulation have been unraveled, such as the activation of the contact and the coagulation systems. Mast cell heparin released upon activation provides negatively charged surfaces for factor XII (FXII) binding and auto-activation. Activated FXII, the initiating serine protease in both the contact and the intrinsic coagulation system, activates factor XI and prekallikrein, respectively. FXII-mediated bradykinin (BK) formation has been proven in the human plasma of anaphylactic patients as well as in experimental models of anaphylaxis. Moreover, the severity of anaphylaxis is correlated with the increase in plasma heparin, BK formation and the intensity of contact system activation. FXII also activates plasminogen in the fibrinolysis system. Mast cell tryptase has been shown to participate in fibrinolysis through plasmin activation and by facilitating the degradation of fibrinogen. Some usual clinical manifestations in anaphylaxis, such as angioedema or hypotension, or other less common, such as metrorrhagia, may be explained by the direct effect of the activation of the coagulation and contact system driven by mast cell mediators. PMID:28798744

Self-equilibrated Tapered Three-stage Tensegrity Mast

NASA Astrophysics Data System (ADS)

Oh, C. L.; Choong, K. K.; Nishimura, T.; Lee, S. W.

2018-04-01

Investigation of tensegrity structures for the space application is ongoing owing to the characteristics of being lightweight and flexible. Tensegrity structures consist of struts and cables are self-stressed and stable under gravitational loading. Form-finding is an important process to obtain the configuration of tensegrity structures that are in self-equilibrated state. Form-finding of tensegrity structures involves a complex computational strategy in solving the geometrical and forces of the structures. This paper aims to form-finding for a tapered three-stage tensegrity mast. The form-finding strategy involves the assemblage of the tensegrity mast, establishment of equilibrium equations and determination of one possible set of coefficient beta. Several cases of configurations with various twist angles with range of 20°-40° are investigated. A configuration with 9 struts and 42 cables satisfying the material elastic conditions was successfully found. The scalable self-equilibrated tensegrity mast is recommended for space applications.

Dysregulation of Aldosterone Secretion in Mast Cell-Deficient Mice.

PubMed

Boyer, Hadrien-Gaël; Wils, Julien; Renouf, Sylvie; Arabo, Arnaud; Duparc, Céline; Boutelet, Isabelle; Lefebvre, Hervé; Louiset, Estelle

2017-12-01

Resident adrenal mast cells have been shown to activate aldosterone secretion in rat and man. Especially, mast cell proliferation has been observed in adrenal tissues from patients with aldosterone-producing adrenocortical adenoma. In the present study, we show that the activity of adrenal mast cells is stimulated by low-sodium diet and correlates with aldosterone synthesis in C57BL/6 and BALB/c mice. We have also investigated the regulation of aldosterone secretion in mast cell-deficient C57BL/6 Kit W-sh/W-sh mice in comparison with wild-type C57BL/6 mice. Kit W-sh/W-sh mice submitted to normal sodium diet had basal plasma aldosterone levels similar to those observed in wild-type animals. Conversely, low-sodium diet unexpectedly induced an exaggerated aldosterone response, which seemed to result from an increase in adrenal renin and angiotensin type 1 receptor expression. Severe hyperaldosteronism was associated with an increase in systolic blood pressure and marked hypokalemia, which favored polyuria. Adrenal renin and angiotensin type 1 receptor overexpression may represent a compensatory mechanism aimed at activating aldosterone production in the absence of mast cells. Finally, C57BL/6 Kit W-sh/W-sh mice represent an unexpected animal model of primary aldosteronism, which has the particularity to be triggered by sodium restriction. © 2017 American Heart Association, Inc.

Relation between mast cells concentration and serotonin expression in chagasic megacolon development.

PubMed

Freitas, M A R; Segatto, N; Tischler, N; de Oliveira, E C; Brehmer, A; da Silveira, A B M

2017-03-01

Chagas' disease is still reaching about 10 million people in the world. In South America, one of the most severe forms of this disease is the megacolon, characterized by severe constipation, dilated sigmoid colon and rectum and severe malnutrition. Previous data suggested that mast cells and serotonin (5-hydroxytryptamine [5-HT]) expression could be involved in intestinal homeostasis control, avoiding the chagasic megacolon development. The aim at this study was to characterize the presence of mast cells and expression of serotonin in chagasic patients with and without megacolon and evaluate the relation between mast cells, serotonin and megacolon development. Our results demonstrated that patients without megacolon feature a large amount of serotonin and few mast cells, while patients with megacolon feature low serotonin expression and a lot of mast cells. We believe that serotonin may be involved in the inflammatory process control, triggered by mast cells, and the presence of this substance in large quantities of the intestine could represent a mechanism of megacolon prevention. © 2017 John Wiley & Sons Ltd.

An Expertise Engine: MAST in the 2020s

NASA Astrophysics Data System (ADS)

Goldston Peek, Joshua Eli; Smith, Arfon M.; Momcheva, Ivelina G.

2018-06-01

The original Hubble Space Telescope archive showed how encapsulating expertise in science-ready data products could accelerate the pace of scientific advancement, and enable extremely productive archival research. In the 2000s, MAST and the Hubble Legacy Archive showed how taking these products to the next level further democratized astronomy, with archival science overtaking PI science as the dominant output of MAST missions. We argue that these data products fundamentally act as a vector for expertise, allowing novice users access to the detailed and advanced techniques of experts. In the 2020s we will see an explosion of data volume, data precision, and data complexity which will demand an even more powerful and sophisticated expertise engine. We’ll discuss how MAST plans to rise to meet that challenge.

Tests of wildlife habitat models to evaluate oak-mast production

USGS Publications Warehouse

Schroeder, R.L.; Vangilder, L.D.

1997-01-01

We measured oak-mast production and forest structure and composition in the Ozark Mountains of Missouri and tested the accuracy of oak-mast prediction variables from 5 Habitat Suitability Index (HSI) species models. Acorn production was positively associated with several measures of abundance and canopy cover of oak trees, and with an index of mast production for all 5 HSI models. We developed 2 modified oak-mast models, based on inputs related to either oak tree density or oak canopy cover and diversity of oak tree species. The revised models accounted for 22-32% of the variance associated with acorn abundance. Future tests of HSI models should consider: (1) the concept of upper limits imposed by habitat and the effects of nonhabitat factors; (2) the benefits of a top-down approach to model development; and (3) testing models across broad geographic regions.

Mycobacterium tuberculosis Catalase Inhibits the Formation of Mast Cell Extracellular Traps

PubMed Central

Campillo-Navarro, Marcia; Leyva-Paredes, Kahiry; Donis-Maturano, Luis; Rodríguez-López, Gloria M.; Soria-Castro, Rodolfo; García-Pérez, Blanca Estela; Puebla-Osorio, Nahum; Ullrich, Stephen E.; Luna-Herrera, Julieta; Flores-Romo, Leopoldo; Sumano-López, Héctor; Pérez-Tapia, Sonia M.; Estrada-Parra, Sergio; Estrada-García, Iris; Chacón-Salinas, Rommel

2018-01-01

Tuberculosis is one of the leading causes of human morbidity and mortality. Mycobacterium tuberculosis (Mtb) employs different strategies to evade and counterattack immune responses persisting for years. Mast cells are crucial during innate immune responses and help clear infections via inflammation or by direct antibacterial activity through extracellular traps (MCETs). Whether Mtb induce MCETs production is unknown. In this study, we report that viable Mtb did not induce DNA release by mast cells, but heat-killed Mtb (HK-Mtb) did. DNA released by mast cells after stimulation with HK-Mtb was complexed with histone and tryptase. MCETs induced with PMA and HK-Mtb were unable to kill live Mtb bacilli. Mast cells stimulated with HK-Mtb induced hydrogen peroxide production, whereas cells stimulated with viable Mtb did not. Moreover, MCETs induction by HK-Mtb was dependent of NADPH oxidase activity, because its blockade resulted in a diminished DNA release by mast cells. Interestingly, catalase-deficient Mtb induced a significant production of hydrogen peroxide and DNA release by mast cells, indicating that catalase produced by Mtb prevents MCETs release by degrading hydrogen peroxide. Our findings show a new strategy employed by Mtb to overcome the immune response through inhibiting MCETs formation, which could be relevant during early stages of infection. PMID:29892297

Mycobacterium tuberculosis Catalase Inhibits the Formation of Mast Cell Extracellular Traps.

PubMed

Campillo-Navarro, Marcia; Leyva-Paredes, Kahiry; Donis-Maturano, Luis; Rodríguez-López, Gloria M; Soria-Castro, Rodolfo; García-Pérez, Blanca Estela; Puebla-Osorio, Nahum; Ullrich, Stephen E; Luna-Herrera, Julieta; Flores-Romo, Leopoldo; Sumano-López, Héctor; Pérez-Tapia, Sonia M; Estrada-Parra, Sergio; Estrada-García, Iris; Chacón-Salinas, Rommel

2018-01-01

Tuberculosis is one of the leading causes of human morbidity and mortality. Mycobacterium tuberculosis (Mtb) employs different strategies to evade and counterattack immune responses persisting for years. Mast cells are crucial during innate immune responses and help clear infections via inflammation or by direct antibacterial activity through extracellular traps (MCETs). Whether Mtb induce MCETs production is unknown. In this study, we report that viable Mtb did not induce DNA release by mast cells, but heat-killed Mtb (HK-Mtb) did. DNA released by mast cells after stimulation with HK-Mtb was complexed with histone and tryptase. MCETs induced with PMA and HK-Mtb were unable to kill live Mtb bacilli. Mast cells stimulated with HK-Mtb induced hydrogen peroxide production, whereas cells stimulated with viable Mtb did not. Moreover, MCETs induction by HK-Mtb was dependent of NADPH oxidase activity, because its blockade resulted in a diminished DNA release by mast cells. Interestingly, catalase-deficient Mtb induced a significant production of hydrogen peroxide and DNA release by mast cells, indicating that catalase produced by Mtb prevents MCETs release by degrading hydrogen peroxide. Our findings show a new strategy employed by Mtb to overcome the immune response through inhibiting MCETs formation, which could be relevant during early stages of infection.

Time domain modal identification/estimation of the mini-mast testbed

NASA Technical Reports Server (NTRS)

Roemer, Michael J.; Mook, D. Joseph

1991-01-01

The Mini-Mast is a 20 meter long 3-dimensional, deployable/retractable truss structure designed to imitate future trusses in space. Presented here are results from a robust (with respect to measurement noise sensitivity), time domain, modal identification technique for identifying the modal properties of the Mini-Mast structure even in the face of noisy environments. Three testing/analysis procedures are considered: sinusoidal excitation near resonant frequencies of the Mini-Mast, frequency response function averaging of several modal tests, and random input excitation with a free response period.

30 CFR 56.7051 - Loose objects on the mast or drill platform.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Loose objects on the mast or drill platform. 56... Drilling and Rotary Jet Piercing Drilling § 56.7051 Loose objects on the mast or drill platform. To prevent injury to personnel, tools and other objects shall not be left loose on the mast or drill platform. ...

30 CFR 56.7051 - Loose objects on the mast or drill platform.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Loose objects on the mast or drill platform. 56... Drilling and Rotary Jet Piercing Drilling § 56.7051 Loose objects on the mast or drill platform. To prevent injury to personnel, tools and other objects shall not be left loose on the mast or drill platform. ...

30 CFR 56.7051 - Loose objects on the mast or drill platform.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Loose objects on the mast or drill platform. 56... Drilling and Rotary Jet Piercing Drilling § 56.7051 Loose objects on the mast or drill platform. To prevent injury to personnel, tools and other objects shall not be left loose on the mast or drill platform. ...

The Mastocytosis Society survey on mast cell disorders: patient experiences and perceptions.

PubMed

Jennings, Susan; Russell, Nancy; Jennings, Blair; Slee, Valerie; Sterling, Lisa; Castells, Mariana; Valent, Peter; Akin, Cem

2014-01-01

Mast cell diseases include mastocytosis and mast cell activation syndromes, some of which have been shown to involve clonal defects in mast cells that result in abnormal cellular proliferation or activation. Numerous clinical studies of mastocytosis have been published, but no population-based comprehensive surveys of patients in the United States have been identified. Few mast cell disease specialty centers exist in the United States, and awareness of these mast cell disorders is limited among nonspecialists. Accordingly, information concerning the experiences of the overall estimated population of these patients has been lacking. To identify the experiences and perceptions of patients with mastocytosis, mast cell activation syndromes, and related disorders, The Mastocytosis Society (TMS), a US based patient advocacy, research, and education organization, conducted a survey of its members and other people known or suspected to be part of this patient population. A Web-based survey was publicized through clinics that treat these patients and through TMS's newsletter, Web site, and online blogs. Both online and paper copies of the questionnaire were provided, together with required statements of consent. The first results are presented for 420 patients. These results include demographics, diagnoses, symptoms, allergies, provoking factors of mast cell symptoms, and disease impact. Patients with mastocytosis and mast cell activation syndromes have provided clinical specialists, collaborators, and other patients with information to enable them to explore and deepen their understanding of the experiences and perceptions of people coping with these disorders. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Twenty-first century mast cell stabilizers

PubMed Central

Finn, D F; Walsh, J J

2013-01-01

Mast cell stabilizing drugs inhibit the release of allergic mediators from mast cells and are used clinically to prevent allergic reactions to common allergens. Despite the relative success of the most commonly prescribed mast cell stabilizer, disodium cromoglycate, in use for the preventative treatment of bronchial asthma, allergic conjunctivitis and vernal keratoconjunctivitis, there still remains an urgent need to design new substances that are less expensive and require less frequent dosing schedules. In this regard, recent developments towards the discovery of the next generation of mast cell stabilizing drugs has included studies on substances isolated from natural sources, biological, newly synthesized compounds and drugs licensed for other indications. The diversity of natural products evaluated range from simple phenols, alkaloids, terpenes to simple amino acids. While in some cases their precise mode of action remains unknown it has nevertheless sparked interest in the development of synthetic derivatives with improved pharmacological properties. Within the purely synthetic class of inhibitors, particular attention has been devoted to the inhibition of important signalling molecules including spleen TK and JAK3. The statin class of cholesterol-lowering drugs as well as nilotinib, a TK inhibitor, are just some examples of clinically used drugs that have been evaluated for their anti-allergic properties. Here, we examine each approach under investigation, summarize the test data generated and offer suggestions for further preclinical evaluation before their therapeutic potential can be realized. Linked Articles This article is part of a themed issue on Histamine Pharmacology Update. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2013.170.issue-1 PMID:23441583

Mast cell dynamics in the house rat (Rattus rattus) ovary during estrus cycle, pregnancy and lactation.

PubMed

Batth, B K; Parshad, R K

2000-02-01

The distribution of mast cells in various ovarian compartments was studied during different stages of the reproductive cycles in Rattus rattus. Two types of mast cell populations were recognized with light microscopy i.e., light purple and deep purple, the latter also includes deeply stained cells with extruded granules. Mast cells identified by electron microscopy showed the ultrastructural features during granule formation and release of their content. Significantly higher numbers of mast cells per unit area of ovary were seen at estrus and diestrus. Numbers of mast cells also remained high during pregnancy with possible involvement of mast cell products in vascularization of corpora lutea. A positive correlation existed between mast cell counts and embryo number during pregnancy. However, numbers of mast cells declined significantly after parturition.

SuperCam_MastUnit

NASA Astrophysics Data System (ADS)

Deleuze, M. D.; Bernardi, P. B.; Caïs, Ph. C.; Perez, R. P.; Rees, J. M. R.; Pares, L. P.; Dubois, B. D.; Parot, Y. P.; Quertier, B. Q.; Maurice, S. M.; Maccabe, K. M.; Wiens, R. W.; Rull, F. R.

2016-10-01

This paper will describe and give a development status of SuperCam's mast unit. SuperCam will be carried on the Mars 2020 rover, and consists in an enhanced version of the ChemCam LIBS which is still performing at the surface of Mars, on Curiosity.

Comparison of Mast Cells Count in Odontogenic Cysts Using Histochemical Staining

PubMed Central

Rajabi-Moghaddam, Mahdieh; Abbaszadeh-Bidokhty, Hamid; Bijani, Ali

2015-01-01

Background & Objectives: Odontogenic cysts are among the most frequent destructive lesions of jaws which their pathogenesis and growth mechanism are not cleared. With respect to different roles of mast cells, they may play a role in the pathogenesis and growth of odontogenic cysts. The aim of present study was to evaluate mast cells in the most common odontogenic cyst. Methods: Thirty paraffin-embedded tissue blocks including 10 radicular cysts, 10 dentigerous cysts and 10 odontogenic keratocysts were used and 5 micron sections stained with toluidine blue and observed by light microscope under ×400 magnification to evaluate mast cells within these cysts. For each case, 5 high-power field areas, selected from hot-spot areas, were considered and each area divided into 3 zones: intra-epithelial zone, sub-epithelial zone and deep zone. Results: Most of the studied cyst showed presence of mast cells. There was not any significant difference in mast cell count between studied cysts ( P -values > 0.05).With respect to intra-epithelial, sub-epithelial and deep zones, there was not any significant difference between three studied cysts. There was not any significant difference between sub-epithelial zone and deep zone within each of these cysts. There was only significant difference between intra-epithelial zone and sub-epithelial zone within dentigerous cysts and odontogenic keratocysts ( P -value < 0.05). Conclusions: Prevalence of mast cells in fibrous wall of odontogenic cysts suggests their activity in these cysts. Mast cells may not be directly involved in the pathogenesis of odontogenic keratocysts. PMID:26351470

Hydrogen inhalation ameliorated mast cell mediated brain injury after ICH in mice

PubMed Central

Manaenko, Anatol; Lekic, Tim; Ma, Qingyi; Zhang, John H.; Tang, Jiping

2012-01-01

OBJECTIVE Hydrogen inhalation was neuroprotective in several brain injury models. Its mechanisms are believed to be related to anti-oxidative stress. We investigated the potential neurovascular protective effect of hydrogen inhalation especially effect on mast cell activation in a mouse model of intracerebral hemorrhage (ICH). DESIGN Controlled in vivo laboratory study. SETTING Animal research laboratory SUBJECTS 171, 8 weeks old male CD-1 mice were used. INTERVENTIONS Collagenase-induced ICH model in 8 weeks old, male, CD-1 mice was used. Hydrogen was administrated via spontaneous inhalation. The blood-brain barrier (BBB) permeability and neurological deficits were investigated at 24 and 72 hours after ICH. Mast cell activation was evaluated by Western blot and immuno-staining. The effects of hydrogen inhalation on mast cell activation were confirmed in an autologous blood injection model ICH. MEASURMENT AND MAIN RESULTS At 24 and 72 hours post-ICH, animals showed BBB disruption, brain edema, neurological deficits, accompanied with phosphorylation of Lyn kinase and release of tryptase, indicating mast cell activation. Hydrogen treatment diminished phosphorylation of Lyn kinase and release of tryptase, decreased accumulation and degranulation of mast cells, attenuated BBB disruption and improved neurobehavioral function. CONCLUSION Activation of mast cells following ICH contributed to increase of BBB permeability and brain edema. Hydrogen inhalation preserved BBB disruption by prevention of mast cell activation after ICH. PMID:23388512

Developmental changes of mast cell populations in the cerebral meninges of the rat

PubMed Central

Michaloudi, Helen; Batzios, Christos; Chiotelli, Maria; Papadopoulos, Georgios C

2007-01-01

It is known that both the dura and the pia mater attract and support the differentiation of mast cells. The present study shows that unevenly distributed mast cells in the cerebral meninges of the rat can be found in perivascular sites and vessel ramification points, but can also be unrelated to the meningeal vasculature. It also documents changes in the number, localization and staining preferences of the mast cells in the two meninges of the developing and mature rat brain. Quantitative examination of all types of histochemically differentiated meningeal mast cells reveals no major (although some exist) differences between right and left side subpopulations, but strongly suggests a different origin and fate of the dural and the pial mast cells. The number of dural mast cells, already high from postnatal day 0, although declining from postnatal day 21 onwards, remains conspicuous up to postnatal day 180. In contrast, pial mast cells are comparatively very few in the first day of the postnatal life, and despite a transient significant increase in the following two weeks, they reach almost zero levels from postnatal day 21. PMID:17822416

Mast Cell, the Neglected Member of the Tumor Microenvironment: Role in Breast Cancer.

PubMed

Aponte-López, Angélica; Fuentes-Pananá, Ezequiel M; Cortes-Muñoz, Daniel; Muñoz-Cruz, Samira

2018-01-01

Mast cells are unique tissue-resident immune cells that secrete a diverse array of biologically active compounds that can stimulate, modulate, or suppress the immune response. Although mounting evidence supports that mast cells are consistently infiltrating tumors, their role as either a driving or an opposite force for cancer progression is still controversial. Particularly, in breast cancer, their function is still under discussion. While some studies have shown a protective role, recent evidence indicates that mast cells enhance blood and lymphatic vessel formation. Interestingly, one of the most important components of the mast cell cargo, the serine protease tryptase, is a potent angiogenic factor, and elevated serum tryptase levels correlate with bad prognosis in breast cancer patients. Likewise, histamine is known to induce tumor cell proliferation and tumor growth. In agreement, mast cell depletion reduces the size of mammary tumors and metastasis in murine models that spontaneously develop breast cancer. In this review, we will discuss the evidence supporting protumoral and antitumoral roles of mast cells, emphasizing recent findings placing mast cells as important drivers of tumor progression, as well as the potential use of these cells or their mediators as therapeutic targets.

Substance P enhances electrical field stimulation-induced mast cell degranulation in rat trachea.

PubMed

Hua, X Y; Back, S M; Tam, E K

1996-06-01

We previously demonstrated in an ex vivo rat tracheal model that chymotryptic activity is an index of mast cell degranulation and that substance P (SP) and electrical field stimulation (EFS) synergistically degranulate mucosal and connective tissue mast cells. In the current study, we found that the facilitatory effect of SP was apparent at concentrations as low as 10(-9) M. This effect was mimicked by 10(-7) M neurokinin A or by 10(-6) M capsaicin and was blocked by the NK1 receptor antagonist CP-96,345. SP + EFS-induced mast cell secretion was significantly attenuated by 10(-6) M tetrodotoxin. The response was also attenuated in tracheas from rats in which sensory nerves had been depleted by systemic pretreatment with capsaicin or in which sympathetic nerves had been depleted by systemic pretreatment with 6-hydroxy-dopamine. Atropine (10(-6) M) or indomethacin (10(-5) M) also attenuated SP + EFS-induced mast cell secretion. Our findings suggest the importance of a sensitizing rather than a direct stimulating effect of SP on mast cell degranulation. SP may increase the sensitivity of mast cells to EFS-discharged mediators or facilitate the release of mast cell-stimulating mediators from autonomic nerves.

125. HYDRAULIC CONTROLS FOR MAST TRENCH DOORS ON LEFT SIDE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

125. HYDRAULIC CONTROLS FOR MAST TRENCH DOORS ON LEFT SIDE OF HYDRAULIC CONTROL PANEL IN UMBILICAL MAST PUMP ROOM (209), LSB (BLDG. 751) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Akt-Dependent Cytokine Production in Mast Cells

PubMed Central

Kitaura, Jiro; Asai, Koichi; Maeda-Yamamoto, Mari; Kawakami, Yuko; Kikkawa, Ushio; Kawakami, Toshiaki

2000-01-01

Cross-linking of FcεRI induces the activation of three protein tyrosine kinases, Lyn, Syk, and Bruton's tyrosine kinase (Btk), leading to the secretion of a panel of proinflammatory mediators from mast cells. This study showed phosphorylation at Ser-473 and enzymatic activation of Akt/protein kinase B, the crucial survival kinase, upon FcεRI stimulation in mouse mast cells. Phosphorylation of Akt is regulated positively by Btk and Syk and negatively by Lyn. Akt in turn can regulate positively the transcriptional activity of interleukin (IL)-2 and tumor necrosis factor (TNF)-α promoters. Transcription from the nuclear factor κB (NF-κB), nuclear factor of activated T cells (NF-AT), and activator protein 1 (AP-1) sites within these promoters is under the control of Akt activity. Accordingly, the signaling pathway involving IκB-α, a cytoplasmic protein that binds NF-κB and inhibits its nuclear translocation, appears to be regulated by Akt in mast cells. Catalytic activity of glycogen synthase kinase (GSK)-3β, a serine/threonine kinase that phosphorylates NF-AT and promotes its nuclear export, seems to be inhibited by Akt. Importantly, Akt regulates the production and secretion of IL-2 and TNF-α in FcεRI-stimulated mast cells. Altogether, these results revealed a novel function of Akt in transcriptional activation of cytokine genes via NF-κB, NF-AT, and AP-1 that contributes to the production of cytokines. PMID:10974038

Mast cells and angiogenesis in wound healing.

PubMed

Gaber, Mohamed A; Seliet, Iman A; Ehsan, Nermin A; Megahed, Mohamed A

2014-02-01

To investigate the role of mast cells and vascular endothelial growth factor (VEGF) as a mediator of angiogenesis to promote wound healing in surgical and pathological scars. The study was carried out on 40 patients who presented with active scar lesions. They were subdivided into 4 groups. They included granulation tissue (10 cases), surgical scar (10 cases), hypertrophic scar (10 cases), and keloid scar (10 cases). Also 10 healthy volunteers of the same age and sex were selected as a control group. Skin biopsies were taken from the patients and the control group. Skin biopsies from clinically assessed studied groups were processed for routine histology and embedded in paraffin. Four sections were prepared from each paraffin block. The first section was stained with hematoxylin and eosin for histological evaluation. The second and third sections were processed for immunostaining of mast cells that contain chymase (MCCs) and mast cells that contain tryptase (MCTs). The fourth section was processed for immunostaining of VEGF. MCCs exhibited mild expression in normal tissue, granulation tissue, and surgical, hypertrophic and keloid scars. MCTs exhibited mild expression in normal tissue, granulation tissue and keloid, whereas moderate expression was exhibited in hypertrophic and surgical scars. VEGF expression was absent in normal tissue, mild in keloid, surgical and hypertrophic scars, and moderate in keloids and granulation tissue. Mast cell expression variation among different scar types signals the pathological evolution of the lesion, and hence may guide the need for therapeutic intervention.

Infiltrating mast cells enhance benign prostatic hyperplasia through IL-6/STAT3/Cyclin D1 signals

PubMed Central

Ou, Zhenyu; He, Yao; Qi, Lin; Zu, Xiongbin; Wu, Longxiang; Cao, Zhenzhen; Li, Yuan; Liu, Longfei; Dube, Daud Athanasius; Wang, Zhi; Wang, Long

2017-01-01

Early evidences have showed that mast cells could infiltrate into benign prostatic hyperplasia (BPH) tissues, but the exact role of mast cells in BPH development remains unclear. In this study, we identified more mast cells existing in human BPH tissues compared with that in the normal prostate. In the in vitro co-culture system, BPH-1 prostate cells promoted activation and migration of mast cells, and mast cells conversely stimulated BPH-1 cells proliferation significantly. Molecular analysis demonstrated that mast cell-derived interleukin 6 (IL-6) could activate STAT3/Cyclin D1 signals in BPH-1 cells. Blocking IL-6 or STAT3 partially reverse the capacity of mast cells to enhance BPH-1 cell proliferation. Our findings suggest that infiltrating mast cells in BPH tissues could promote BPH development via IL-6/STAT3/Cyclin D1 signals. Therefore, targeting infiltrating mast cells may improve the therapeutic effect of BPH. PMID:28938626

Getting NuSTAR on target: predicting mast motion

NASA Astrophysics Data System (ADS)

Forster, Karl; Madsen, Kristin K.; Miyasaka, Hiromasa; Craig, William W.; Harrison, Fiona A.; Rana, Vikram R.; Markwardt, Craig B.; Grefenstette, Brian W.

2016-07-01

The Nuclear Spectroscopic Telescope Array (NuSTAR) is the first focusing high energy (3-79 keV) X-ray observatory operating for four years from low Earth orbit. The X-ray detector arrays are located on the spacecraft bus with the optics modules mounted on a flexible mast of 10.14m length. The motion of the telescope optical axis on the detectors during each observation is measured by a laser metrology system and matches the pre-launch predictions of the thermal flexing of the mast as the spacecraft enters and exits the Earths shadow each orbit. However, an additional motion of the telescope field of view was discovered during observatory commissioning that is associated with the spacecraft attitude control system and an additional flexing of the mast correlated with the Solar aspect angle for the observation. We present the methodology developed to predict where any particular target coordinate will fall on the NuSTAR detectors based on the Solar aspect angle at the scheduled time of an observation. This may be applicable to future observatories that employ optics deployed on extendable masts. The automation of the prediction system has greatly improved observatory operations efficiency and the reliability of observation planning.

Getting NuSTAR on Target: Predicting Mast Motion

NASA Technical Reports Server (NTRS)

Forster, Karl; Madsen, Kristin K.; Miyasaka, Hiroshima; Craig, William W.; Harrison, Fiona A.; Rana, Vikram R.; Markwardt, Craig B.; Grenfenstette, Brian W.

2017-01-01

The Nuclear Spectroscopic Telescope Array (NuSTAR) is the first focusing high energy (3-79 keV) X-ray observatory operating for four years from low Earth orbit. The X-ray detector arrays are located on the spacecraft bus with the optics modules mounted on a flexible mast of 10.14m length. The motion of the telescope optical axis on the detectors during each observation is measured by a laser metrology system and matches the pre-launch predictions of the thermal flexing of the mast as the spacecraft enters and exits the Earths shadow each orbit. However, an additional motion of the telescope field of view was discovered during observatory commissioning that is associated with the spacecraft attitude control system and an additional flexing of the mast correlated with the Solar aspect angle for the observation. We present the methodology developed to predict where any particular target coordinate will fall on the NuSTAR detectors based on the Solar aspect angle at the scheduled time of an observation. This may be applicable to future observatories that employ optics deployed on extendable masts. The automation of the prediction system has greatly improved observatory operations efficiency and the reliability of observation planning.

Mast cells in systemic and cutaneous lupus erythematosus.

PubMed

Kaczmarczyk-Sekuła, Karolina; Dyduch, Grzegorz; Kostański, Marcin; Wielowieyska-Szybińska, Dorota; Szpor, Joanna; Białas, Magdalena; Okoń, Krzysztof

2015-12-01

Mast cells (MCs) are known to be regulators of inflammation and immunity, due to the released mediators and expressed cell surface molecules. Lupus erythematosus (LE) is a group of diseases which can be systemic or limited to the skin. Due to the fact that cytokines and chemokines produced by inflammatory cells contribute to the pathogenesis of LE, we quantified the number of mast cells present in the skin. The aim of the study was to compare the chymase-positive and tryptase-positive mast cell counts within skin biopsies from patients with systemic lupus erythematosus (SLE), discoid lupus erythematosus (DLE) and subacute cutaneous lupus erythematosus (SCLE). The material consisted of 45 skin biopsies: 6 with SLE, 34 with DLE and 5 with SCLE. Chymase- and tryptase-positive cells were stained by immunohistochemistry and counted. The mean count of chymase-positive mast cells was 85.14 hpf for the whole group, 35.83 for SLE, 88.48 for DLE and 121.6 for SCLE. The mean count of tryptase-positive cells was 120.05 hpf for the entire group, 59.17 for SLE, 126.42 for DLE and 149.8 for SCLE. The differences between groups were significant for chymase- and tryptase-positive cells.

Mast Cell Targeted Chimeric Toxin Can Be Developed as an Adjunctive Therapy in Colon Cancer Treatment

PubMed Central

Wang, Shan; Li, Linmei; Shi, Renren; Liu, Xueting; Zhang, Junyan; Zou, Zehong; Hao, Zhuofang; Tao, Ailin

2016-01-01

The association of colitis with colorectal cancer has become increasingly clear with mast cells being identified as important inflammatory cells in the process. In view of the relationship between mast cells and cancer, we studied the effect and mechanisms of mast cells in the development of colon cancer. Functional and mechanistic insights were gained from ex vivo and in vivo studies of cell interactions between mast cells and CT26 cells. Further evidence was reversely obtained in studies of mast cell targeted Fcε-PE40 chimeric toxin. Experiments revealed mast cells could induce colon tumor cell proliferation and invasion. Cancer progression was found to be related to the density of mast cells in colonic submucosa. The activation of MAPK, Rho-GTPase, and STAT pathways in colon cancer cells was triggered by mast cells during cell-to-cell interaction. Lastly, using an Fcε-PE40 chimeric toxin we constructed, we confirmed the promoting effect of mast cells in development of colon cancer. Mast cells are a promoting factor of colon cancer and thus also a potential therapeutic target. The Fcε-PE40 chimeric toxin targeting mast cells could effectively prevent colon cancer in vitro and in vivo. Consequently, these data may demonstrate a novel immunotherapeutic approach for the treatment of tumors. PMID:26978404

Cre-mediated cell ablation contests mast cell contribution in models of antibody- and T cell-mediated autoimmunity.

PubMed

Feyerabend, Thorsten B; Weiser, Anne; Tietz, Annette; Stassen, Michael; Harris, Nicola; Kopf, Manfred; Radermacher, Peter; Möller, Peter; Benoist, Christophe; Mathis, Diane; Fehling, Hans Jörg; Rodewald, Hans-Reimer

2011-11-23

Immunological functions of mast cells remain poorly understood. Studies in Kit mutant mice suggest key roles for mast cells in certain antibody- and T cell-mediated autoimmune diseases. However, Kit mutations affect multiple cell types of both immune and nonimmune origin. Here, we show that targeted insertion of Cre-recombinase into the mast cell carboxypeptidase A3 locus deleted mast cells in connective and mucosal tissues by a genotoxic Trp53-dependent mechanism. Cre-mediated mast cell eradication (Cre-Master) mice had, with the exception of a lack of mast cells and reduced basophils, a normal immune system. Cre-Master mice were refractory to IgE-mediated anaphylaxis, and this defect was rescued by mast cell reconstitution. This mast cell-deficient strain was fully susceptible to antibody-induced autoimmune arthritis and to experimental autoimmune encephalomyelitis. Differences comparing Kit mutant mast cell deficiency models to selectively mast cell-deficient mice call for a systematic re-evaluation of immunological functions of mast cells beyond allergy. Copyright © 2011 Elsevier Inc. All rights reserved.

41. VIEW OF UMBILICAL MAST AND LAUNCH PAD FROM LAUNCHER; ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

41. VIEW OF UMBILICAL MAST AND LAUNCH PAD FROM LAUNCHER; SOUTH FACE OF MST IN BACKGROUND. RAIL SYSTEM FROM BASE OF MST PARALLEL TO MAST. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

126. REDUNDANCY SYSTEM CONTROLS FOR UMBILICAL MAST RETRACTION AT LOWER ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

126. REDUNDANCY SYSTEM CONTROLS FOR UMBILICAL MAST RETRACTION AT LOWER LEFT SIDE OF HYDRAULIC CONTROL PANEL IN UMBILICAL MAST PUMP ROOM (209), LSB (BLDG. 751) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

109. REDUNDANCY SYSTEM CONTROLS FOR UMBILICAL MAST RETRACTION AT LOWER ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

109. REDUNDANCY SYSTEM CONTROLS FOR UMBILICAL MAST RETRACTION AT LOWER LEFT SIDE OF HYDRAULIC CONTROL PANEL IN UMBILICAL MAST PUMP ROOM (109), LSB (BLDG. 770) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

[Sex differences in neuromodulation of mucosal mast cells in the rat jejunum].

PubMed

Gottwald, T; Becker, H D; Stead, R H

1997-01-01

The effect of electrical stimulation of both cervical vagal nerves on mucosal mast cells in the jejunum was investigated in an in vivo animal model with rats of both sexes. Males showed a significant increase of mast cell densities after electrical stimulation (1.0 mA, 5 Hz, 5 ms, 12 min) in the lamina propria. Simultaneously, we observed a significant increase of tissue histamine levels (ANOVA: P < 0.05), whereas serum levels remained unchanged. However, even though females had significantly higher levels throughout compared to males (ANOVA: P < 0.05), they did not show any significant reaction to electrical stimulation. These in vivo data support morphological and in vitro data from other investigators, who hypothesized a functional interaction between mucosal mast cells and nerves. However, degranulation seems to be a poor in situ indicator for mast-cell stimulation, as mast-cell densities increased in males, while the percentage of degranulated cells remained the same in all groups (about 40%). Instead, electrical stimulation of the vagal nerve seems to trigger histamine synthesis, or simply stabilization of mast cells. Interestingly, this phenomenon seems to be sex-dependent, suggesting a regulatory role for sex hormones in this scenario.

Relationship between Numerous Mast Cells and Early Follicular Development in Neonatal MRL/MpJ Mouse Ovaries

PubMed Central

Nakamura, Teppei; Otsuka, Saori; Ichii, Osamu; Sakata, Yuko; Nagasaki, Ken-Ichi; Hashimoto, Yoshiharu; Kon, Yasuhiro

2013-01-01

In the neonatal mouse ovary, clusters of oocytes called nests break into smaller cysts and subsequently form individual follicles. During this period, we found numerous mast cells in the ovary of MRL/MpJ mice and investigated their appearance and morphology with follicular development. The ovarian mast cells, which were already present at postnatal day 0, tended to localize adjacent to the surface epithelium. Among 11 different mouse strains, MRL/MpJ mice possessed the greatest number of ovarian mast cells. Ovarian mast cells were also found in DBA/1, BALB/c, NZW, and DBA/2 mice but rarely in C57BL/6, NZB, AKR, C3H/He, CBA, and ICR mice. The ovarian mast cells expressed connective tissue mast cell markers, although mast cells around the surface epithelium also expressed a mucosal mast cell marker in MRL/MpJ mice. Some ovarian mast cells migrated into the oocyte nests and directly contacted the compressed and degenerated oocytes. In MRL/MpJ mice, the number of oocytes in the nest was significantly lower than in the other strains, and the number of oocytes showed a positive correlation with the number of ovarian mast cells. The gene expression of a mast cell marker also correlated with the expression of an oocyte nest marker, suggesting a link between the appearance of ovarian ? 4mast cells and early follicular development. Furthermore, the expression of follicle developmental markers was significantly higher in MRL/MpJ mice than in C57BL/6 mice. These results indicate that the appearance of ovarian mast cells is a unique phenotype of neonatal MRL/MpJ mice, and that ovarian mast cells participate in early follicular development, especially nest breakdown. PMID:24124609

PAI1 mediates fibroblast-mast cell interactions in skin fibrosis.

PubMed

Pincha, Neha; Hajam, Edries Yousaf; Badarinath, Krithika; Batta, Surya Prakash Rao; Masudi, Tafheem; Dey, Rakesh; Andreasen, Peter; Kawakami, Toshiaki; Samuel, Rekha; George, Renu; Danda, Debashish; Jacob, Paul Mazhuvanchary; Jamora, Colin

2018-05-01

Fibrosis is a prevalent pathological condition arising from the chronic activation of fibroblasts. This activation results from the extensive intercellular crosstalk mediated by both soluble factors and direct cell-cell connections. Prominent among these are the interactions of fibroblasts with immune cells, in which the fibroblast-mast cell connection, although acknowledged, is relatively unexplored. We have used a Tg mouse model of skin fibrosis, based on expression of the transcription factor Snail in the epidermis, to probe the mechanisms regulating mast cell activity and the contribution of these cells to this pathology. We have discovered that Snail-expressing keratinocytes secrete plasminogen activator inhibitor type 1 (PAI1), which functions as a chemotactic factor to increase mast cell infiltration into the skin. Moreover, we have determined that PAI1 upregulates intercellular adhesion molecule type 1 (ICAM1) expression on dermal fibroblasts, rendering them competent to bind to mast cells. This heterotypic cell-cell adhesion, also observed in the skin fibrotic disorder scleroderma, culminates in the reciprocal activation of both mast cells and fibroblasts, leading to the cascade of events that promote fibrogenesis. Thus, we have identified roles for PAI1 in the multifactorial program of fibrogenesis that expand its functional repertoire beyond its canonical role in plasmin-dependent processes.

Decreased number of mast cells infiltrating into needle biopsy specimens leads to a better prognosis of prostate cancer

PubMed Central

Nonomura, N; Takayama, H; Nishimura, K; Oka, D; Nakai, Y; Shiba, M; Tsujimura, A; Nakayama, M; Aozasa, K; Okuyama, A

2007-01-01

Mast cell infiltration is often observed around human tumours. Inflammatory cells such as macrophages, neutrophils and mast cells infiltrating around tumours are known to contribute to tumour growth; however, the clinical significance of mast cell invasion in prostate cancer (PCa) has not been investigated. Mast cell infiltration was evaluated in 104 patients (age range, 45–88 years; median, 72 years), who underwent needle biopsy of the prostate and were confirmed to have PCa. Needle biopsy specimens of prostate were sliced into 5-μm-thick sections and immunostained for mast cells with monoclonal antibody against mast cell-specific tryptase. Mast cells were counted systematically under a microscope (× 400 magnification), and the relations between mast cell numbers and clinicopathologic findings were evaluated. The mast cell count was evaluated for prognostic value by multivariate analysis. Mast cells were immunostained around the cancer foci. The median number of mast cells in each case was 16. The mast cell count was higher around cancer foci in patients with higher Gleason scores than in those with low Gleason scores. The mast cell number correlated well with clinical stage (P<0.001). Prostate-specific antigen-free survival of patients with higher mast cell counts was better than that in patients with lower mast cell counts (P<0.001). Multivariate analysis revealed that mast cell count was a significant prognostic factor (P<0.005). The number of mast cells infiltrating around cancer foci in prostate biopsy specimens can be a significant prognostic factor of PCa. PMID:17848955

Defective bone repair in mast cell-deficient Cpa3Cre/+ mice.

PubMed

Ramirez-GarciaLuna, Jose Luis; Chan, Daniel; Samberg, Robert; Abou-Rjeili, Mira; Wong, Timothy H; Li, Ailian; Feyerabend, Thorsten B; Rodewald, Hans-Reimer; Henderson, Janet E; Martineau, Paul A

2017-01-01

In the adult skeleton, cells of the immune system interact with those of the skeleton during all phases of bone repair to influence the outcome. Mast cells are immune cells best known for their pathologic role in allergy, and may be involved in chronic inflammatory and fibrotic disorders. Potential roles for mast cells in tissue homeostasis, vascularization and repair remain enigmatic. Previous studies in combined mast cell- and Kit-deficient KitW-sh/W-sh mice (KitW-sh) implicated mast cells in bone repair but KitW-sh mice suffer from additional Kit-dependent hematopoietic and non- hematopoietic deficiencies that could have confounded the outcome. The goal of the current study was to compare bone repair in normal wild type (WT) and Cpa3Cre/+ mice, which lack mast cells in the absence of any other hematopoietic or non- hematopoietic deficiencies. Repair of a femoral window defect was characterized using micro CT imaging and histological analyses from the early inflammatory phase, through soft and hard callus formation, and finally the remodeling phase. The data indicate 1) mast cells appear in healing bone of WT mice but not Cpa3Cre/+ mice, beginning 14 days after surgery; 2) re-vascularization of repair tissue and deposition of mineralized bone was delayed and dis-organised in Cpa3Cre/+ mice compared with WT mice; 3) the defects in Cpa3Cre/+ mice were associated with little change in anabolic activity and biphasic alterations in osteoclast and macrophage activity. The outcome at 56 days postoperative was complete bridging of the defect in most WT mice and fibrous mal-union in most Cpa3Cre/+ mice. The results indicate that mast cells promote bone healing, possibly by recruiting vascular endothelial cells during the inflammatory phase and coordinating anabolic and catabolic activity during tissue remodeling. Taken together the data indicate that mast cells have a positive impact on bone repair.

Defective bone repair in mast cell-deficient Cpa3Cre/+ mice

PubMed Central

Chan, Daniel; Samberg, Robert; Abou-Rjeili, Mira; Wong, Timothy H.; Li, Ailian; Feyerabend, Thorsten B.; Rodewald, Hans-Reimer; Henderson, Janet E.; Martineau, Paul A.

2017-01-01

In the adult skeleton, cells of the immune system interact with those of the skeleton during all phases of bone repair to influence the outcome. Mast cells are immune cells best known for their pathologic role in allergy, and may be involved in chronic inflammatory and fibrotic disorders. Potential roles for mast cells in tissue homeostasis, vascularization and repair remain enigmatic. Previous studies in combined mast cell- and Kit-deficient KitW-sh/W-sh mice (KitW-sh) implicated mast cells in bone repair but KitW-sh mice suffer from additional Kit-dependent hematopoietic and non- hematopoietic deficiencies that could have confounded the outcome. The goal of the current study was to compare bone repair in normal wild type (WT) and Cpa3Cre/+ mice, which lack mast cells in the absence of any other hematopoietic or non- hematopoietic deficiencies. Repair of a femoral window defect was characterized using micro CT imaging and histological analyses from the early inflammatory phase, through soft and hard callus formation, and finally the remodeling phase. The data indicate 1) mast cells appear in healing bone of WT mice but not Cpa3Cre/+ mice, beginning 14 days after surgery; 2) re-vascularization of repair tissue and deposition of mineralized bone was delayed and dis-organised in Cpa3Cre/+ mice compared with WT mice; 3) the defects in Cpa3Cre/+ mice were associated with little change in anabolic activity and biphasic alterations in osteoclast and macrophage activity. The outcome at 56 days postoperative was complete bridging of the defect in most WT mice and fibrous mal-union in most Cpa3Cre/+ mice. The results indicate that mast cells promote bone healing, possibly by recruiting vascular endothelial cells during the inflammatory phase and coordinating anabolic and catabolic activity during tissue remodeling. Taken together the data indicate that mast cells have a positive impact on bone repair. PMID:28350850

Proliferation of protease-enriched mast cells in sarcoptic skin lesions of raccoon dogs.

PubMed

Noviana, D; W Harjanti, D; Otsuka, Y; Horii, Y

2004-07-01

Skin sites, tongue, lung, liver, jejunum and rectum from two raccoon dogs with Sarcoptes scabiei infestation and five normal (control) raccoon dogs were examined in terms of the distribution, proteoglycan properties and protease activity of mast cells. Infestation with S. scabiei caused a significant increase in the number of dermal mast cells. While the number of mast cells (average +/- standard deviation) in specimens of skin from the dorsum, dorsal neck, dorsal hind foot and dorsal fore foot was 40.0 +/- 19.8/mm2 in control animals, it was 236.1 +/- 58.9/mm2 in the skin of mange-infested animals. Histochemical analysis revealed the glycosaminoglycan, heparin, within the mast cells of all organs examined in both control and affected animals. Enzyme-histochemical detection of serine proteases demonstrated an increase in mast-cell-specific protease activity (i.e., chymase and tryptase) in the skin of infested animals. The percentage of mast cells demonstrating chymase activity was 53.0 +/- 27.4% in control animals and 73.8 +/- 19.4% in mite-infested animals. The corresponding results for tryptase activity were 53.5 +/- 25.2% and 89.4 +/- 9.8%. Increases in mast cell chymase or tryptase activity, or both, were also observed within other organs of the infected animals, but the total number of mast cells found at such sites (with the exception of liver and ventrolateral pinna) did not differ from those of control animals. Copyright 2004 Elsevier Ltd.

127. HYDRAULIC CONTROLS AND GAUGES FOR THE UMBILICAL MAST ON ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

127. HYDRAULIC CONTROLS AND GAUGES FOR THE UMBILICAL MAST ON UPPER RIGHT SIDE OF HYDRAULIC CONTROL PANEL IN UMBILICAL MAST PUMP ROOM (209), LSB (BLDG. 751) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

123. UMBILICAL MAST PUMP ROOM (209), LSB (BLDG. 751). PUMP ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

123. UMBILICAL MAST PUMP ROOM (209), LSB (BLDG. 751). PUMP ON LEFT; HYDRAULIC CONTROL PANEL FOR UMBILICAL MAST AND TRENCH DOORS IN CENTER OF ROOM, FACING WEST. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Molecular mechanism of mast cell–mediated innate defense against endothelin and snake venom sarafotoxin

PubMed Central

Schneider, Lars A.; Schlenner, Susan M.; Feyerabend, Thorsten B.; Wunderlin, Markus; Rodewald, Hans-Reimer

2007-01-01

Mast cells are protective against snake venom sarafotoxins that belong to the endothelin (ET) peptide family. The molecular mechanism underlying this recently recognized innate defense pathway is unknown, but secretory granule proteases have been invoked. To specifically disrupt a single protease function without affecting expression of other proteases, we have generated a mouse mutant selectively lacking mast cell carboxypeptidase A (Mc-cpa) activity. Using this mutant, we have now identified Mc-cpa as the essential protective mast cell enzyme. Mass spectrometry of peptide substrates after cleavage by normal or mutant mast cells showed that removal of a single amino acid, the C-terminal tryptophan, from ET and sarafotoxin by Mc-cpa is the principle molecular mechanism underlying this very rapid mast cell response. Mast cell proteases can also cleave ET and sarafotoxin internally, but such “nicking” is not protective because intramolecular disulfide bridges maintain peptide function. We conclude that mast cells attack ET and sarafotoxin exactly at the structure required for toxicity, and hence sarafotoxins could not “evade” Mc-cpa's substrate specificity without loss of toxicity. PMID:17923505

Neutrophil Recruitment by Tumor Necrosis Factor from Mast Cells in Immune Complex Peritonitis

NASA Astrophysics Data System (ADS)

Zhang, Yan; Ramos, Bernard F.; Jakschik, Barbara A.

1992-12-01

During generalized immune complex-induced inflammation of the peritoneal cavity, two peaks of tumor necrosis factor (TNF) were observed in the peritoneal exudate of normal mice. In mast cell-deficient mice, the first peak was undetected, and the second peak of TNF and neutrophil influx were significantly reduced. Antibody to TNF significantly inhibited neutrophil infiltration in normal but not in mast cell-deficient mice. Mast cell repletion of the latter normalized TNF, neutrophil mobilization, and the effect of the antibody to TNF. Thus, in vivo, mast cells produce the TNF that augments neutrophil emigration.

Mast cell sarcoma of the larynx.

PubMed Central

Horny, H P; Parwaresch, M R; Kaiserling, E; Müller, K; Olbermann, M; Mainzer, K; Lennert, K

1986-01-01

A 74 year old woman presented with a primary subglottic tumour. Neither cutaneous mastocytosis (urticaria pigmentosa) nor spread to the bone marrow, liver, or spleen were detected. About two years after initial manifestation of the tumour nodular skin metastases appeared, as well as local recurrence in the larynx. Despite chemotherapy and radiation the disease progressed and was fatal. The terminal phase was characterised by generalisation of the mast cell tumour with diffuse infiltration of bone marrow and, shortly before death, leukaemic transformation. The patient died four years after onset of disease with symptoms of a hemorrhagic diathesis. As far as we know this is the first case of mast cell sarcoma to be reported in man. Images PMID:3088063

Vincristine therapy for mast cell tumors in dogs.

PubMed

McCaw, D L; Miller, M A; Bergman, P J; Withrow, S J; Moore, A S; Knapp, D W; Fowler, D; Johnson, J C

1997-01-01

Twenty-seven dogs with naturally occurring mast cell tumors were treated with weekly i.v. injections of vincristine (0.75 mg/m2) for 4 treatments. Two dogs (7%) had a partial response. Nine dogs (32%) had treatment stopped prematurely because of toxicity or a perceived deterioration in their quality of life. We conclude that vincristine is ineffective as a sole treatment for measurable mast cell tumors in dogs and produces an undesirable number of adverse reactions.

The Mast Cell Degranulator Compound 48/80 Directly Activates Neurons

PubMed Central

Schemann, Michael; Kugler, Eva Maria; Buhner, Sabine; Eastwood, Christopher; Donovan, Jemma; Jiang, Wen; Grundy, David

2012-01-01

Background Compound 48/80 is widely used in animal and tissue models as a “selective” mast cell activator. With this study we demonstrate that compound 48/80 also directly activates enteric neurons and visceral afferents. Methodology/Principal Findings We used in vivo recordings from extrinsic intestinal afferents together with Ca++ imaging from primary cultures of DRG and nodose neurons. Enteric neuronal activation was examined by Ca++ and voltage sensitive dye imaging in isolated gut preparations and primary cultures of enteric neurons. Intraluminal application of compound 48/80 evoked marked afferent firing which desensitized on subsequent administration. In egg albumen-sensitized animals, intraluminal antigen evoked a similar pattern of afferent activation which also desensitized on subsequent exposure to antigen. In cross-desensitization experiments prior administration of compound 48/80 failed to influence the mast cell mediated response. Application of 1 and 10 µg/ml compound 48/80 evoked spike discharge and Ca++ transients in enteric neurons. The same nerve activating effect was observed in primary cultures of DRG and nodose ganglion cells. Enteric neuron cultures were devoid of mast cells confirmed by negative staining for c-kit or toluidine blue. In addition, in cultured enteric neurons the excitatory action of compound 48/80 was preserved in the presence of histamine H1 and H2 antagonists. The mast cell stabilizer cromolyn attenuated compound 48/80 and nicotine evoked Ca++ transients in mast cell-free enteric neuron cultures. Conclusions/Significance The results showed direct excitatory action of compound 48/80 on enteric neurons and visceral afferents. Therefore, functional changes measured in tissue or animal models may involve a mast cell independent effect of compound 48/80 and cromolyn. PMID:23272218

KSC01padig074

NASA Image and Video Library

2001-02-12

KENNEDY SPACE CENTER, Fla. -- This closeup shows Space Shuttle Discovery as it travels to Launch Pad 39B. Underneath Discovery is the Mobile Launcher Platform, a two-story movable launch base. Part of the MPLM is the tail service mast, seen here at the bottom of the wind and next to the Shuttle’s main engines. The tail service mast is 31 feet high, 15 feet long and 9 feet wide. A second TSM is on the other side. They support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft T-0 umbilicals. Discovery will be flying on mission STS-102 to the International Space Station. Its payload is the Multi-Purpose Logistics Module Leonardo, a “moving van,” to carry laboratory racks filled with equipment, experiments and supplies to and from the Space Station aboard the Space Shuttle. The flight will also carry the Expedition Two crew up to the Space Station, replacing Expedition One, who will return to Earth on Discovery. Launch is scheduled for March 8 at 6:45 a.m. EST

CD25 is expressed by canine cutaneous mast cell tumors but not by cutaneous connective tissue mast cells.

PubMed

Meyer, A; Gruber, A D; Klopfleisch, R

2012-11-01

Canine cutaneous mast cell tumors (MCT) of different histological grades have distinct biological behaviors. However, little is known about underlying molecular mechanisms that lead to tumor development and increasing malignancy with higher tumor grade. Recent studies have identified the interleukin-2 receptor (IL-2R) subunits CD25 and CD2 as markers that distinguish nonneoplastic from neoplastic mast cells in human systemic mastocytosis. In this study, their potential as a marker for canine MCT and their possible impact on MCT carcinogenesis were evaluated. mRNA expression levels of both genes were compared between grade 1 (n = 12) and grade 3 (n = 8) MCT, and protein expression levels of CD25 were compared in 90 MCT of different tumor grades. mRNA expression levels of both CD25 and CD2 were upregulated in grade 3 MCT. In contrast, CD25 protein was expressed by fewer tumor cells and at decreased levels in grade 3 tumors, while most grade 1 MCT had strong CD25 protein expression. Moreover, CD25 was not expressed by nonneoplastic, resting cutaneous mast cells, while few presumably activated mast cells in tissue samples from dogs with allergic dermatitis had weak CD25 expression. Taken together, these findings suggest that CD25 may play a critical role in early MCT development and may be a stimulatory factor in grade 1 MCT, while grade 3 MCT seem to be less dependent on CD25. Because of the low number of CD25-positive tumor cells in high-grade tumors, the usefulness of CD25 as a tumor marker is, however, questionable.

Effect of sugammadex on rocuronium induced changes in pancreatic mast cells.

PubMed

Kalkan, Yıldıray; Tumkaya, Levent; Bostan, Habib; Tomak, Yakup; Altuner, Durdu; Yilmaz, Adnan; Erdivanli, Başar; Bedir, Recep; Yalcin, Alper; Turan, Alparslan

2015-08-01

Mast cells play a vital role in hypersensitivity reactions. Rocuronium is known to cause mast cell mobilization, hypersensitivity, and pancreatitis. The aim of this study was to investigate the effects of sugammadex on pancreatic changes due to rocuronium. A total of 42 Sprague-Dawley male rats were divided into six equal groups to receive either rocuronium 1 mg/kg intravenously (i.v., R group), rocuronium 1 mg/kg + sugammadex 16 mg/kg i.v. (RS16 group), rocuronium 1 mg/kg + sugammadex 96 mg/kg i.v. (RS96 group), sugammadex 16 mg/kg (S16), sugammadex 96 mg/kg i.v. (S96 group), or 0.9% sodium chloride (control group). Sugammadex was administered 5s later following rocuronium. In R group, mast count was higher, and the distribution rate of granules and nuclear changes were different compared with other groups. Distribution rate of granules in groups S16 and S96 were similar to the control group and lower compared with other groups. The amount of mast cells and granule density in groups RS16 and RS96 was lower compared with R group. The amount of mast cells in groups RS16 and RS96 was significantly lower compared with other treatment groups. These results suggest that sugammadex may have an inhibitory effect on mobilization and morphological changes in pancreatic mast cells induced by administration of rocuronium and sugammadex in rats. © The Author(s) 2013.

Malignant mast cell tumor in an African hedgehog (Atelerix albiventris).

PubMed

Raymond, J T; White, M R; Janovitz, E B

1997-01-01

In November 1995, a malignant mast cell tumor (mastocytoma) was diagnosed in an adult African hedgehog (Atelerix albiventris) from a zoological park (West Lafayette, Indiana, USA). The primary mast cell tumor presented as a firm subcutaneous mass along the ventrum of the neck. Metastasis to the right submandibular lymph node occurred.

Effect of fruits of Opuntia elatior Mill on mast cell degranulation

PubMed Central

Chauhan, Sanjay P.; Sheth, N. R.; Suhagia, B. N.

2015-01-01

Background: The presence of potentially active nutrients and their multifunctional properties make prickly pear a perfect candidate for the production of phytopharmaceutical products. Among the numerous Opuntia species, bioactive compounds have been isolated and characterized primarily from Opuntia ficus-indica, Opuntia polycantha, Opuntia stricta, Opuntia dilleni for various medicinal properties. Objective: Based on the traditional use of prickly pear for enhancement of immune function, the objective of the present study to evaluate the effect of prickly pear on mast cell degranulation function. Materials and Methods: The Opuntia fruit juice (OFJ) (10-200 μl/ml) were studied for the effect on sensitized rat peritoneal mast cell degranulation induced by immunological (egg albumin), and nonimmunological (compound 48/80) stimuli and compared with that of the reference standard, sodium cromoglycate and ketotifen (10 μg/ml). Results and Conclusion: The OFJ exhibited significantly (P < 0.001) concentration dependent inhibition of mast cell degranulation. The IC50 value of OFJ was found 12.24 and 18 μl/ml for immunological and nonimmunological induced mast cell degranulation, respectively. The betacyanin is an active principle compound in prickly pear that may responsible for mast cell stabilizing action. PMID:25883521

Extendable retractable telescopic mast for deployable structures

NASA Technical Reports Server (NTRS)

Schmid, M.; Aguirre, M.

1986-01-01

The Extendable and Retractable Mast (ERM) which is presently developed by Dornier in the frame of an ESA-contract, will be used to deploy and retract large foldable structures. The design is based on a telescopic carbon-fiber structure with high stiffness, strength and pointing accuracy. To verify the chosen design, a breadboard model of an ERM was built and tested under thermal vacuum (TV)-conditions. It is planned as a follow-on development to manufacture and test an Engineering Model Mast. The Engineering Model will be used to establish the basis for an ERM-family covering a wide range of requirements.

Masting behaviour in a Mediterranean pine tree alters seed predator selection on reproductive output.

PubMed

Moreira, X; Abdala-Roberts, L; Zas, R; Merlo, E; Lombardero, M J; Sampedro, L; Mooney, K A

2016-11-01

Context-dependency in species interactions is widespread and can produce concomitant patterns of context-dependent selection. Masting (synchronous production of large seed crops at irregular intervals by a plant population) has been shown to reduce seed predation through satiation (reduction in rates of seed predation with increasing seed cone output) and thus represents an important source of context-dependency in plant-animal interactions. However, the evolutionary consequences of such dynamics are not well understood. Here we describe masting behaviour in a Mediterranean model pine species (Pinus pinaster) and present a test of the effects of masting on selection by seed predators on reproductive output. We predicted that masting, by enhancing seed predator satiation, could in turn strengthen positive selection by seed predators for larger cone output. For this we collected six-year data (spanning one mast year and five non-mast years) on seed cone production and seed cone predation rates in a forest genetic trial composed by 116 P. pinaster genotypes. Following our prediction, we found stronger seed predator satiation during the masting year, which in turn led to stronger seed predator selection for increased cone production relative to non-masting years. These findings provide evidence that masting can alter the evolutionary outcome of plant-seed predator interactions. More broadly, our findings highlight that changes in consumer responses to resource abundance represent a widespread mechanism for predicting and understanding context dependency in plant-consumer evolutionary dynamics. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

Confinement & Stability in MAST

NASA Astrophysics Data System (ADS)

Akers, Rob

2001-10-01

Transition to H-mode has been achieved in the MAST spherical tokamak (ST) for both ohmically and neutral beam heated plasmas (P_NBI ~ 0.5-1.5MW), resulting in double-null diverted discharges containing both regular and irregular edge localised modes (ELMs). The observed L-H power threshold is ~10 times higher than predicted by established empirical scalings. L-H transition in MAST is accompanied by a sharp increase in edge density gradient, the efficient conversion of internal electron Bernstein waves into free space waves, the onset and saturation of edge poloidal rotation and a marked decrease in turbulence. During ELM free periods, a reduction in outboard power deposition width is observed using a Langmuir probe array. A novel divertor structure has been installed to counter the resulting increase in target heat-flux by applying a toroidally varying potential to the divertor plasma, theory suggesting that convective broadening of the scrape off layer will take place. Global confinement in H-mode is found to routinely exceed the international IPB(y,2) scaling, even for discharges approaching the Greenwald density. In an attempt to further extend the density range (densities in excess of Greenwald having been achieved for plasma currents up to 0.8MA) a multi-pellet injector has been installed at the low-field-side. In addition, high field side fuelling can be supplied via a gas-feed located at the centre-column mid-plane, this technique having been found to significantly enhance H-mode accessibility and quality. A range of stability issues will be discussed, including vertical displacement events, the rich variety of high frequency MHD seen in MAST and the physics of the Neoclassical Tearing Mode. This work was funded by the UK Department of Trade and Industry and by EURATOM. The NBI equipment is on loan from ORNL and the pellet injector was provided by FOM.

Mast cells are dispensable in a genetic mouse model of chronic dermatitis.

PubMed

Sulcova, Jitka; Meyer, Michael; Guiducci, Eva; Feyerabend, Thorsten B; Rodewald, Hans-Reimer; Werner, Sabine

2015-06-01

Chronic inflammatory skin diseases, such as atopic dermatitis, affect a large percentage of the population, but the role of different immune cells in the pathogenesis of these disorders is largely unknown. Recently, we found that mice lacking fibroblast growth factor receptor 1 (Fgfr1) and Fgfr2 (K5-R1/R2 mice) in the epidermis have a severe impairment in the epidermal barrier, which leads to the development of a chronic inflammatory skin disease that shares many features with human atopic dermatitis. Using Fgfr1-/Fgfr2-deficient mice, we analyzed the consequences of the loss of mast cells. Mast cells accumulated and degranulated in the skin of young Fgfr1-/Fgfr2-deficient mice, most likely as a consequence of increased expression of the mast cell chemokine Ccl2. The increase in mast cells occurred before the development of histological abnormalities, indicating a functional role of these cells in the inflammatory skin phenotype. To test this hypothesis, we mated the Fgfr1-/Fgfr2-deficient mice with mast cell-deficient CreMaster mice. Surprisingly, loss of mast cells did not or only mildly affect keratinocyte proliferation, epidermal thickness, epidermal barrier function, accumulation and activation of different immune cells, or expression of different proinflammatory cytokines in the skin. These results reveal that mast cells are dispensable for the development of chronic inflammation in response to a defect in the epidermal barrier. Copyright © 2015 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Listeria monocytogenes Alters Mast Cell Phenotype, Mediator and Osteopontin Secretion in a Listeriolysin-Dependent Manner

PubMed Central

Jobbings, Catherine E.; Sandig, Hilary; Whittingham-Dowd, Jayde K.; Roberts, Ian S.; Bulfone-Paus, Silvia

2013-01-01

Whilst mast cells participate in the immune defence against the intracellular bacterium Listeria monocytogenes, there is conflicting evidence regarding the ability of L. monocytogenes to infect mast cells. It is known that the pore-forming toxin listeriolysin (LLO) is important for mast cell activation, degranulation and the release of pro-inflammatory cytokines. Mast cells, however, are a potential source of a wide range of cytokines, chemokines and other mediators including osteopontin, which contributes to the clearing of L. monocytogenes infections in vivo, although its source is unknown. We therefore aimed to resolve the controversy of mast cell infection by L. monocytogenes and investigated the extent of mediator release in response to the bacterium. In this paper we show that the infection of bone marrow-derived mast cells by L. monocytogenes is inefficient and LLO-independent. LLO, however, is required for calcium-independent mast cell degranulation as well as for the transient and selective downregulation of cell surface CD117 (c-kit) on mast cells. We demonstrate that in addition to the key pro-inflammatory cytokines TNF-α and IL-6, mast cells release a wide range of other mediators in response to L. monocytogenes. Osteopontin, IL-2, IL-4, IL-13 and granulocyte macrophage colony-stimulating factor (GM-CSF), and chemokines including CCL2, CCL3, CCL4 and CCL5 are released in a MyD88-dependent manner. The wide range of mediators released by mast cells in response to L. monocytogenes may play an important role in the recruitment and activation of a variety of immune cells in vivo. The cocktail of mediators, however, is unlikely to skew the immune response to a particular effector response. We propose that mast cells provide a hitherto unreported source of osteopontin, and may provide an important role in co-ordinating the immune response during Listeria infection. PMID:23460827

Mast cells play no role in the pathogenesis of postoperative ileus induced by intestinal manipulation.

PubMed

Gomez-Pinilla, Pedro J; Farro, Giovanna; Di Giovangiulio, Martina; Stakenborg, Nathalie; Némethova, Andrea; de Vries, Annick; Liston, Adrian; Feyerabend, Thorsten B; Rodewald, Hans-Reimer; Rodewald, Hans-Reimwer; Boeckxstaens, Guy E; Matteoli, Gianluca

2014-01-01

Intestinal manipulation (IM) during abdominal surgery results in intestinal inflammation leading to hypomotility or ileus. Mast cell activation is thought to play a crucial role in the pathophysiology of postoperative ileus (POI). However, this conclusion was mainly drawn using mast cell-deficient mouse models with abnormal Kit signaling. These mice also lack interstitial cells of Cajal (ICC) resulting in aberrant gastrointestinal motility even prior to surgery, compromising their use as model to study POI. To avoid these experimental weaknesses we took advantage of a newly developed knock-in mouse model, Cpa3(Cre/+) , devoid of mast cells but with intact Kit signaling. The role of mast cells in the development of POI and intestinal inflammation was evaluated assessing gastrointestinal transit and muscularis externa inflammation after IM in two strains of mice lacking mast cells, i.e. Kit(W-sh/W-sh) and Cpa3(Cre/+) mice, and by use of the mast cell stabilizer cromolyn. Kit(W-sh/W-sh) mice lack ICC networks and already revealed significantly delayed gastrointestinal transit even before surgery. IM did not further delay intestinal transit, but induced infiltration of myeloperoxidase positive cells, expression of inflammatory cytokines and recruitment of monocytes and neutrophils into the muscularis externa. On the contrary, Cpa3(Cre/+) mice have a normal network of ICC and normal gastrointestinal. Surprisingly, IM in Cpa3(Cre/+) mice caused delay in gut motility and intestinal inflammation as in wild type littermates mice (Cpa3(+/+) ). Furthermore, treatment with the mast cell inhibitor cromolyn resulted in an inhibition of mast cells without preventing POI. Here, we confirm that IM induced mast cell degranulation. However, our data demonstrate that mast cells are not required for the pathogenesis of POI in mice. Although there might be species differences between mouse and human, our results argue against mast cell inhibitors as a therapeutic approach to shorten POI.

Hydrogen inhalation ameliorated mast cell-mediated brain injury after intracerebral hemorrhage in mice.

PubMed

Manaenko, Anatol; Lekic, Tim; Ma, Qingyi; Zhang, John H; Tang, Jiping

2013-05-01

Hydrogen inhalation was neuroprotective in several brain injury models. Its mechanisms are believed to be related to antioxidative stress. We investigated the potential neurovascular protective effect of hydrogen inhalation especially effect on mast cell activation in a mouse model of intracerebral hemorrhage. Controlled in vivo laboratory study. Animal research laboratory. One hundred seventy-one 8-week-old male CD-1 mice were used. Collagenase-induced intracerebral hemorrhage model in 8-week-old male CD-1 mice was used. Hydrogen was administrated via spontaneous inhalation. The blood-brain barrier permeability and neurologic deficits were investigated at 24 and 72 hours after intracerebral hemorrhage. Mast cell activation was evaluated by Western blot and immuno-staining. The effects of hydrogen inhalation on mast cell activation were confirmed in an autologous blood injection model intracerebral hemorrhage. At 24 and 72 hours post intracerebral hemorrhage, animals showed blood-brain barrier disruption, brain edema, and neurologic deficits, accompanied with phosphorylation of Lyn kinase and release of tryptase, indicating mast cell activation. Hydrogen treatment diminished phosphorylation of Lyn kinase and release of tryptase, decreased accumulation and degranulation of mast cells, attenuated blood-brain barrier disruption, and improved neurobehavioral function. Activation of mast cells following intracerebral hemorrhage contributed to increase of blood-brain barrier permeability and brain edema. Hydrogen inhalation preserved blood-brain barrier disruption by prevention of mast cell activation after intracerebral hemorrhage.

STS-104 Atlantis on pad after RSS rollback

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- Workers clean the mobile launcher platform on which sits Space Shuttle Atlantis. They are standing in front of one of two tail service masts on either side of the Shuttle, in front of each wing. The masts support the fluid, gas and electrical requirements of the orbiters liquid oxygen and liquid hydrogen aft T-0 umbilicals. Launch on mission STS-104 is scheduled for 5:04 a.m. July 12. The launch is the 10th assembly flight to the International Space Station. Along with a crew of five, Atlantis will carry the joint airlock module as primary payload.

Mast cells in citric acid-induced cough of guinea pigs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lai, Y.-L.; Lin, T.-Y.

2005-01-01

It was demonstrated previously that mast cells play an important role in citric acid (CA)-induced airway constriction. To investigate the role of mast cells in CA-induced cough, three experiments were carried out in this study. In the first experiment, 59 guinea pigs were employed and we used compound 48/80 to deplete mast cells, cromolyn sodium to stabilize mast cells, MK-886 to inhibit leukotriene synthesis, pyrilamine to antagonize histamine H{sub 1} receptor, methysergide to antagonize serotonin receptor, and indomethacin to inhibit cyclooxygenase. In the second experiment, 56 compound 48/80-pretreated animals were divided into two parts; the first one was used tomore » test the role of exogenous leukotriene (LT) C{sub 4}, while the second one to test the role of exogenous histamine in CA-induced cough. Each animal with one of the above pretreatments was exposed sequentially to saline (baseline) and CA (0.6 M) aerosol, each for 3 min. Then, cough was recorded for 12 min using a barometric body plethysmograph. In the third experiment, the activation of mast cells upon CA inhalation was investigated by determining arterial plasma histamine concentration in 17 animals. Exposure to CA induced a marked increase in cough number. Compound 48/80, cromolyn sodium, MK-886 and pyrilamine, but not indomethacin or methysergide, significantly attenuated CA-induced cough. Injection of LTC{sub 4} or histamine caused a significant increase in CA-induced cough in compound 48/80-pretreated animals. In addition, CA inhalation caused significant increase in plasma histamine concentration, which was blocked by compound 48/80 pretreatment. These results suggest that mast cells play an important role in CA aerosol inhalation-induced cough via perhaps mediators LTs and histamine.« less

Spatiotemporally and Mechanically Controlled Triggering of Mast Cells using Atomic Force Microscopy

PubMed Central

Hu, Kenneth K.; Bruce, Marc A.; Butte, Manish J.

2014-01-01

Mast cells are thought to be sensitive to mechanical forces, for example, coughing in asthma or pressure in “physical urticarias”. Conversion of mechanical forces to biochemical signals could potentially augment antigenic signaling. Studying the combined effects of mechanical and antigenic cues on mast cells and other hematopoietic cells has been elusive. Here, we present an approach using a modified atomic force microscope cantilever to deliver antigenic signals to mast cells while simultaneously applying mechanical forces. We developed a strategy to concurrently record degranulation events by fluorescence microscopy during antigenic triggering. Finally, we also measured the mechanical forces generated by mast cells while antigen receptors are ligated. We showed that mast cells respond to antigen delivered by the AFM cantilever with prompt degranulation and the generation of strong pushing and pulling forces. We did not discern any relationship between applied mechanical forces and the kinetics of degranulation. These experiments present a new method for dissecting the interactions of mechanical and biochemical cues in signaling responses of immune cells. PMID:24777418

Th17 cell-mediated immune responses promote mast cell proliferation by triggering stem cell factor in keratinocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cho, Kyung-Ah; Park, Minhwa; Kim, Yu-Hee

Although mast cells are traditionally thought to function as effector cells in allergic responses, they have increasingly been recognized as important regulators of various immune responses. Mast cells mature locally; thus, tissue-specific influences are important for promoting mast cell accumulation and survival in the skin and the gastrointestinal tract. In this study, we determined the effects of keratinocytes on mast cell accumulation during Th17-mediated skin inflammation. We observed increases in dermal mast cells in imiquimod-induced psoriatic dermatitis in mice accompanied by the expression of epidermal stem cell factor (SCF), a critical mast cell growth factor. Similar to mouse epidermal keratinocytes,more » SCF was highly expressed in the human HaCaT keratinocyte cell line following stimulation with IL−17. Further, keratinocytes promoted mast cell proliferation following stimulation with IL−17 in vitro. However, the effects of keratinocytes on mast cells were significantly diminished in the presence of anti−CD117 (stem cell factor receptor) blocking antibodies. Taken together, our results revealed that the Th17-mediated inflammatory environment promotes mast cell accumulation through keratinocyte-derived SCF. - Highlights: • Psoriasis-like skin inflammation increase dermal mast cells. • Keratinocyte produce stem cell factor in psoriasis-like skin inflammation. • Keratinocyte promote mast cell proliferation by stem cell factor dependent manner.« less

Mast Cell Activation in Brain Injury, Stress, and Post-traumatic Stress Disorder and Alzheimer's Disease Pathogenesis.

PubMed

Kempuraj, Duraisamy; Selvakumar, Govindhasamy P; Thangavel, Ramasamy; Ahmed, Mohammad E; Zaheer, Smita; Raikwar, Sudhanshu P; Iyer, Shankar S; Bhagavan, Sachin M; Beladakere-Ramaswamy, Swathi; Zaheer, Asgar

2017-01-01

Mast cells are localized throughout the body and mediate allergic, immune, and inflammatory reactions. They are heterogeneous, tissue-resident, long-lived, and granulated cells. Mast cells increase their numbers in specific site in the body by proliferation, increased recruitment, increased survival, and increased rate of maturation from its progenitors. Mast cells are implicated in brain injuries, neuropsychiatric disorders, stress, neuroinflammation, and neurodegeneration. Brain mast cells are the first responders before microglia in the brain injuries since mast cells can release prestored mediators. Mast cells also can detect amyloid plaque formation during Alzheimer's disease (AD) pathogenesis. Stress conditions activate mast cells to release prestored and newly synthesized inflammatory mediators and induce increased blood-brain barrier permeability, recruitment of immune and inflammatory cells into the brain and neuroinflammation. Stress induces the release of corticotropin-releasing hormone (CRH) from paraventricular nucleus of hypothalamus and mast cells. CRH activates glial cells and mast cells through CRH receptors and releases neuroinflammatory mediators. Stress also increases proinflammatory mediator release in the peripheral systems that can induce and augment neuroinflammation. Post-traumatic stress disorder (PTSD) is a traumatic-chronic stress related mental dysfunction. Currently there is no specific therapy to treat PTSD since its disease mechanisms are not yet clearly understood. Moreover, recent reports indicate that PTSD could induce and augment neuroinflammation and neurodegeneration in the pathogenesis of neurodegenerative diseases. Mast cells play a crucial role in the peripheral inflammation as well as in neuroinflammation due to brain injuries, stress, depression, and PTSD. Therefore, mast cells activation in brain injury, stress, and PTSD may accelerate the pathogenesis of neuroinflammatory and neurodegenerative diseases including AD. This

Mast Cell Activation in Brain Injury, Stress, and Post-traumatic Stress Disorder and Alzheimer's Disease Pathogenesis

PubMed Central

Kempuraj, Duraisamy; Selvakumar, Govindhasamy P.; Thangavel, Ramasamy; Ahmed, Mohammad E.; Zaheer, Smita; Raikwar, Sudhanshu P.; Iyer, Shankar S.; Bhagavan, Sachin M.; Beladakere-Ramaswamy, Swathi; Zaheer, Asgar

2017-01-01

Mast cells are localized throughout the body and mediate allergic, immune, and inflammatory reactions. They are heterogeneous, tissue-resident, long-lived, and granulated cells. Mast cells increase their numbers in specific site in the body by proliferation, increased recruitment, increased survival, and increased rate of maturation from its progenitors. Mast cells are implicated in brain injuries, neuropsychiatric disorders, stress, neuroinflammation, and neurodegeneration. Brain mast cells are the first responders before microglia in the brain injuries since mast cells can release prestored mediators. Mast cells also can detect amyloid plaque formation during Alzheimer's disease (AD) pathogenesis. Stress conditions activate mast cells to release prestored and newly synthesized inflammatory mediators and induce increased blood-brain barrier permeability, recruitment of immune and inflammatory cells into the brain and neuroinflammation. Stress induces the release of corticotropin-releasing hormone (CRH) from paraventricular nucleus of hypothalamus and mast cells. CRH activates glial cells and mast cells through CRH receptors and releases neuroinflammatory mediators. Stress also increases proinflammatory mediator release in the peripheral systems that can induce and augment neuroinflammation. Post-traumatic stress disorder (PTSD) is a traumatic-chronic stress related mental dysfunction. Currently there is no specific therapy to treat PTSD since its disease mechanisms are not yet clearly understood. Moreover, recent reports indicate that PTSD could induce and augment neuroinflammation and neurodegeneration in the pathogenesis of neurodegenerative diseases. Mast cells play a crucial role in the peripheral inflammation as well as in neuroinflammation due to brain injuries, stress, depression, and PTSD. Therefore, mast cells activation in brain injury, stress, and PTSD may accelerate the pathogenesis of neuroinflammatory and neurodegenerative diseases including AD. This

Overview of MAST results

NASA Astrophysics Data System (ADS)

Chapman, I. T.; Adamek, J.; Akers, R. J.; Allan, S.; Appel, L.; Asunta, O.; Barnes, M.; Ben Ayed, N.; Bigelow, T.; Boeglin, W.; Bradley, J.; Brünner, J.; Cahyna, P.; Carr, M.; Caughman, J.; Cecconello, M.; Challis, C.; Chapman, S.; Chorley, J.; Colyer, G.; Conway, N.; Cooper, W. A.; Cox, M.; Crocker, N.; Crowley, B.; Cunningham, G.; Danilov, A.; Darrow, D.; Dendy, R.; Diallo, A.; Dickinson, D.; Diem, S.; Dorland, W.; Dudson, B.; Dunai, D.; Easy, L.; Elmore, S.; Field, A.; Fishpool, G.; Fox, M.; Fredrickson, E.; Freethy, S.; Garzotti, L.; Ghim, Y. C.; Gibson, K.; Graves, J.; Gurl, C.; Guttenfelder, W.; Ham, C.; Harrison, J.; Harting, D.; Havlickova, E.; Hawke, J.; Hawkes, N.; Hender, T.; Henderson, S.; Highcock, E.; Hillesheim, J.; Hnat, B.; Holgate, J.; Horacek, J.; Howard, J.; Huang, B.; Imada, K.; Jones, O.; Kaye, S.; Keeling, D.; Kirk, A.; Klimek, I.; Kocan, M.; Leggate, H.; Lilley, M.; Lipschultz, B.; Lisgo, S.; Liu, Y. Q.; Lloyd, B.; Lomanowski, B.; Lupelli, I.; Maddison, G.; Mailloux, J.; Martin, R.; McArdle, G.; McClements, K.; McMillan, B.; Meakins, A.; Meyer, H.; Michael, C.; Militello, F.; Milnes, J.; Morris, A. W.; Motojima, G.; Muir, D.; Nardon, E.; Naulin, V.; Naylor, G.; Nielsen, A.; O'Brien, M.; O'Gorman, T.; Ono, Y.; Oliver, H.; Pamela, S.; Pangione, L.; Parra, F.; Patel, A.; Peebles, W.; Peng, M.; Perez, R.; Pinches, S.; Piron, L.; Podesta, M.; Price, M.; Reinke, M.; Ren, Y.; Roach, C.; Robinson, J.; Romanelli, M.; Rozhansky, V.; Saarelma, S.; Sangaroon, S.; Saveliev, A.; Scannell, R.; Schekochihin, A.; Sharapov, S.; Sharples, R.; Shevchenko, V.; Silburn, S.; Simpson, J.; Storrs, J.; Takase, Y.; Tanabe, H.; Tanaka, H.; Taylor, D.; Taylor, G.; Thomas, D.; Thomas-Davies, N.; Thornton, A.; Turnyanskiy, M.; Valovic, M.; Vann, R.; Walkden, N.; Wilson, H.; van Wyk, F.; Yamada, T.; Zoletnik, S.; MAST; MAST Upgrade Teams

2015-10-01

The Mega Ampère Spherical Tokamak (MAST) programme is strongly focused on addressing key physics issues in preparation for operation of ITER as well as providing solutions for DEMO design choices. In this regard, MAST has provided key results in understanding and optimizing H-mode confinement, operating with smaller edge localized modes (ELMs), predicting and handling plasma exhaust and tailoring auxiliary current drive. In all cases, the high-resolution diagnostic capability on MAST is complemented by sophisticated numerical modelling to facilitate a deeper understanding. Mitigation of ELMs with resonant magnetic perturbations (RMPs) with toroidal mode number nRMP = 2, 3, 4, 6 has been demonstrated: at high and low collisionality; for the first ELM following the transition to high confinement operation; during the current ramp-up; and with rotating nRMP = 3 RMPs. nRMP = 4, 6 fields cause less rotation braking whilst the power to access H-mode is less with nRMP = 4 than nRMP = 3, 6. Refuelling with gas or pellets gives plasmas with mitigated ELMs and reduced peak heat flux at the same time as achieving good confinement. A synergy exists between pellet fuelling and RMPs, since mitigated ELMs remove fewer particles. Inter-ELM instabilities observed with Doppler backscattering are consistent with gyrokinetic simulations of micro-tearing modes in the pedestal. Meanwhile, ELM precursors have been strikingly observed with beam emission spectroscopy (BES) measurements. A scan in beta at the L-H transition shows that pedestal height scales strongly with core pressure. Gyro-Bohm normalized turbulent ion heat flux (as estimated from the BES data) is observed to decrease with increasing tilt of the turbulent eddies. Fast ion redistribution by energetic particle modes depends on density, and access to a quiescent domain with ‘classical’ fast ion transport is found above a critical density. Highly efficient electron Bernstein wave current drive (1 A W-1) has been achieved

Mast Cells Regulate Epidermal Barrier Function and the Development of Allergic Skin Inflammation.

PubMed

Sehra, Sarita; Serezani, Ana P M; Ocaña, Jesus A; Travers, Jeffrey B; Kaplan, Mark H

2016-07-01

Atopic dermatitis is a chronic inflammatory skin disease characterized by infiltration of eosinophils, T helper cells, and mast cells. The role of mast cells in atopic dermatitis is not completely understood. To define the effects of mast cells on skin biology, we observed that mast cells regulate the homeostatic expression of epidermal differentiation complex and other skin genes. Decreased epidermal differentiation complex gene expression in mice that genetically lack mast cells (Kit(W-sh/W-sh) mice) is associated with increased uptake of protein antigens painted on the skin by dendritic cells (DCs) compared with similarly treated wild-type mice, suggesting a protective role for mast cells in exposure to nominal environmental allergens. To test this further, we crossed Kit(W-sh/W-sh) mice with signal transducer and activator of transcription 6 (i.e., Stat6) VT transgenic mice that develop spontaneous atopic dermatitis-like disease that is dependent on T helper cell 2 cytokines and is associated with high serum concentrations of IgE. We observed that Stat6VT × Kit(W-sh/W-sh) mice developed more frequent and more severe allergic skin inflammation than Stat6VT transgenic mice that had mast cells. Together, these studies suggest that mast cells regulate epidermal barrier function and have a potential protective role in the development of atopic dermatitis-like disease. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

The role of colonic mast cells and myenteric plexitis in patients with diverticular disease.

PubMed

Bassotti, Gabrio; Villanacci, Vincenzo; Nascimbeni, Riccardo; Antonelli, Elisabetta; Cadei, Moris; Manenti, Stefania; Lorenzi, Luisa; Titi, Amin; Salerni, Bruno

2013-02-01

Gut mast cells represent an important cell population involved in intestinal homeostasis and inflammatory processes. However, their possible role has not to date been investigated in colonic diverticular disease. This study aims to evaluate colonic mast cells in patients undergoing surgery for diverticular disease. Surgical resection samples from 27 patients undergoing surgery for diverticular disease (12 emergency procedures for severe disease and 15 elective procedures) were evaluated. The number of mast cells was assessed in the various layers by means of a specific antibody (tryptase) and compared with those evaluated in ten controls. In patients with mast cells degranulation, double immunohistochemistry, also assessing nerve fibres, was carried out. In addition, the presence of myenteric plexitis was sought. Compared with controls, the number of mast cells in diverticular patients was significantly increased, both as an overall figure and in the various layers of the large bowel. In patients in whom mast cells degranulation was present, these were always closed to nerve fibres. No differences were found between the two subgroups of patients with respect to the number and distribution of mast cells; however, all patients undergoing emergency surgery (but none of those undergoing elective procedures) had myenteric plexitis, represented by lymphocytic infiltration in 67 % and eosinophilic infiltration in 33 % of cases. Patients with diverticular disease display an increase of mast cells in the large bowel. The presence of myenteric plexitis in those with complicated, severe disease, suggest that this could represent a histopathologic marker of more aggressive disease.

An essential role for platelet-activating factor in activating mast cell migration following ultraviolet irradiation

PubMed Central

Chacón-Salinas, Rommel; Chen, Limo; Chávez-Blanco, Alma D.; Limón-Flores, Alberto Y.; Ma, Ying; Ullrich, Stephen E.

2014-01-01

The UVB (290–320 nm) radiation in sunlight is responsible for inducing skin cancer. Exposure to UV radiation is also immunosuppressive, and the systemic immune suppression induced by UV is a well-recognized risk factor for cancer induction. As UVB radiation is absorbed within the upper layers of the skin, indirect mechanisms must play a role in activating systemic immune suppression. One prominent example is mast cell migration, which from the skin to the draining LN is an essential step in the cascade of events leading to immune suppression. What triggers mast cell migration is not entirely clear. Here, we tested the hypothesis that PAF, a lipid mediator of inflammation produced by the skin in response to UV exposure, is involved. Mast cell-deficient mice (KitW-sh/W-sh) are resistant to the suppressive effect of UV radiation, and reconstituting mast cell-deficient mice with normal bone marrow-derived mast cells restores susceptibility to immunosuppression. However, when mast cells from PAFR−/− mice were used, the reconstituted mice were not susceptible to the suppressive effects of UV. Furthermore, PAFR−/− mice showed impaired UV-induced mast cell migration when compared with WT mice. Finally, injecting PAF into WT mice mimicked the effect of UV irradiation and induced mast cell migration but not in PAFR−/− mice. Our findings indicate that PAFR binding induces mast cells to migrate from the skin to the LNs, where they mediate immune suppression. PMID:24009177

Role of Mast Cells in Oral Lichen Planus and Oral Lichenoid Reactions.

PubMed

Ramalingam, Suganya; Malathi, Narasimhan; Thamizhchelvan, Harikrishnan; Sangeetha, Narasimhan; Rajan, Sharada T

2018-01-01

Oral lichen planus (OLP) is a chronic T cell mediated disease of oral mucosa, skin, and its appendages with a prevalence of 0.5 to 2.6% worldwide. Oral lichenoid reactions (OLR) are a group of lesions with diverse aetiologies but have clinical and histological features similar to OLP, thereby posing a great challenge in differentiating both lesions. Mast cells are multifunctional immune cells that play a major role in the pathogenesis of lichen planus by release of certain chemical mediators. Increased mast cell densities with significant percentage of degranulation have been observed as a consistent finding in pathogenesis of oral lichen planus. The current study was aimed at quantifying the mast cells in histopathological sections of OLP and OLR thereby aiding a means of distinguishing these lesions. The study group involved 21 cases of oral lichen planus, 21 cases of oral lichenoid reactions, and 10 control specimens of normal buccal mucosa. All the cases were stained with Toluidine Blue and routine haematoxylin and eosin and the mast cells were quantified. The results were analyzed using the Kruskal-Wallis test and an intergroup analysis was performed using Mann-Whitney U test. The number of mast cells showed an increased value in oral lichen planus when compared to oral lichenoid reaction and thus an estimation of mast cells count could aid in distinguishing OLP from OLR histopathologically.

Mechanism of low-level laser therapy (LLLT) effects on rat mast cells

NASA Astrophysics Data System (ADS)

Popov, Gennady K.; Solovyova, Ludmila I.; Kosel, Arnold I.

2000-11-01

The low power laser radiation is widely applied for treatment of various diseases. In our research we investigated the influence of low power laser radiation on the mast cells degranulation process. The object of the research were the mesentery mast cells of the rat thin intestine. A loop of thin intestine was irradiated by the therapeutic diode laser device Uley - 2K (lambda - 890 nm, pulse). The process of mast cells degranulation served as a criterion for their functional activity estimation. The estimation was fulfilled with the help of light microscope (toluidine blue staining, pH02,0; degranulating mast cells counting on 100 cells; immersion technique; X 980). To study the dependence of degranulation process of mast cells irradiated with lasre from intracellular calcium (Ca2+) concentration we applied 0,000015 M solution of verapamil, which was applied to the mesentery for 2 minutes. Laser radiation (890 nm) stimulates mesentery mast cells degranulation. This effect is dose-dependent. Maximal degranulation was registered after laser irradiation wiht power 25 mW, exposure time 15-30 s (energy density 7.5 x 103 J/m2 to 6 x 104 j/m2). Further increasing of exposure time caused the effect decreasing. The results of our experiments with verpamil let us suppose light interaction with the voltage-dependent subunit of calcium channel, changing intracellular Ca2+ and leading to stimulatory effects.

Expression and function of CD8 alpha/beta chains on rat and human mast cells.

PubMed

Kim, Mi-Sun; Kim, Sung-Hoon; Lee, Hye-Jung; Kim, Hyung-Min

2004-03-01

The expression and functional role of CD8 glycoprotein, a marker of cytotoxic/suppressor T lymphocytes and NK cells, were not studied on freshly isolated connective tissue type rat peritoneal mast cells, a rat mucosal type mast cell line (RBL 2H3), or human mast cell line (HMC-1). We used the reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis, immunohistochemistry and enzyme-linked immunosorbent assay. RT-PCR and Western blot analysis identified the presence of CD8 alpha/beta chains on the mast cells, and immunohistochemistry confirmed CD8alpha expression on rat or human mast cells. Functional studies demonstrated that stimulation of CD8 alpha/beta chains on rat mast cells induced the secretion of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6), which are regarded as important mediators during infection. However, co-stimulation with stem cell factor had no effect on CD8-induced mediator secretion. Our findings demonstrate novel biological roles of CD8 molecules in mast cells.

Skylab rescue space vehicle flight readiness test

NASA Technical Reports Server (NTRS)

Jevitt, S. J.

1973-01-01

A Skylab Rescue Space Vehicle flight readiness test is described which ensures that space vehicle systems are in a state of flight readiness and are compatible with associated ground support equipment. The functions of propellant loading, umbilical ejection, ignition, holddown arm release, liftoff, and service arm and tail service mast retraction are simulated. The test outline is presented along with a list of references, intercommunications information, operations interface control chart, and flight test.

Connecting long-tail scientists with big data centers using SaaS

NASA Astrophysics Data System (ADS)

Percivall, G. S.; Bermudez, L. E.

2012-12-01

Big data centers and long tail scientists represent two extremes in the geoscience research community. Interoperability and inter-use based on software-as-a-service (SaaS) increases access to big data holdings by this underserved community of scientists. Large, institutional data centers have long been recognized as vital resources in the geoscience community. Permanent data archiving and dissemination centers provide "access to the data and (are) a critical source of people who have experience in the use of the data and can provide advice and counsel for new applications." [NRC] The "long-tail of science" is the geoscience researchers that work separate from institutional data centers [Heidorn]. Long-tail scientists need to be efficient consumers of data from large, institutional data centers. Discussions in NSF EarthCube capture the challenges: "Like the vast majority of NSF-funded researchers, Alice (a long-tail scientist) works with limited resources. In the absence of suitable expertise and infrastructure, the apparently simple task that she assigns to her graduate student becomes an information discovery and management nightmare. Downloading and transforming datasets takes weeks." [Foster, et.al.] The long-tail metaphor points to methods to bridge the gap, i.e., the Web. A decade ago, OGC began building a geospatial information space using open, web standards for geoprocessing [ORM]. Recently, [Foster, et.al.] accurately observed that "by adopting, adapting, and applying semantic web and SaaS technologies, we can make the use of geoscience data as easy and convenient as consumption of online media." SaaS places web services into Cloud Computing. SaaS for geospatial is emerging rapidly building on the first-generation geospatial web, e.g., OGC Web Coverage Service [WCS] and the Data Access Protocol [DAP]. Several recent examples show progress in applying SaaS to geosciences: - NASA's Earth Data Coherent Web has a goal to improve science user experience using

Machine Tool Advanced Skills Technology Program (MAST). Overview and Methodology.

ERIC Educational Resources Information Center

Texas State Technical Coll., Waco.

The Machine Tool Advanced Skills Technology Program (MAST) is a geographical partnership of six of the nation's best two-year colleges located in the six states that have about one-third of the density of metals-related industries in the United States. The purpose of the MAST grant is to develop and implement a national training model to overcome…

Immunoexpression of tryptase-positive mast cells in periapical granulomas and radicular cysts.

PubMed

Costa Neto, H; de Andrade, A L D L; Gordón-Núñez, M A; Freitas, R de A; Galvão, H C

2015-08-01

To evaluate and compare the immunoexpression of tryptase in samples of periapical granulomas (PGs) and radicular cysts (RCs) correlating it with the type of lesion, localization, intensity of the inflammatory infiltrate and thickness of the cystic epithelial lining, in order to gain insight into the phlogistic role of these cells in the lesions studied. Twenty-five PGs and twenty-five RCs obtained from human teeth without endodontic treatment were submitted to morphological and immunohistochemical analysis using anti-tryptase antibody. Mast cells were identified and counted in three regions: intra-epithelial, central/superficial and deep portions. The data were analysed using the Mann-Whitney U-test (P < 0.05). In comparison with RCs, PGs exhibited higher immunoexpression of tryptase-positive mast cells located in both central/superficial and deep regions (P < 0.001 and P < 0.001, respectively). When considering the total number of mast cells and disregarding the location, the number of tryptase-positive mast cells increased gradually from RCs to PGs (P < 0.001). Lesions with inflammatory infiltrate grade III had greater number of tryptase-positive mast cells located in both central/superficial and deep regions than lesions with inflammatory infiltrates grade II (P = 0.045 and P = 0.025). When the location was ignored, the lesions with inflammatory infiltrate grade III also exhibited higher immunostaining of tryptase-positive mast cells (P = 0.01). Tryptase-positive mast cells were present in chronic periapical lesions in a larger number in periapical granulomas than in radicular cysts, in both central/superficial and deep regions. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Characterization of Mast Cell Activation Syndrome.

PubMed

Afrin, Lawrence B; Self, Sally; Menk, Jeremiah; Lazarchick, John

2017-03-01

Mast cell activation syndrome (MCAS), a recently recognized nonneoplastic mast cell disease driving chronic multisystem inflammation and allergy, appears prevalent and thus important. We report the first systematic characterization of a large MCAS population. Demographics, comorbidities, symptoms, family histories, physical examination and laboratory findings were reviewed in 298 retrospective and 115 prospective patients with MCAS. Blood samples from prospective subjects were examined by flow cytometry for clonal mast cell disease and tested for cytokines potentially driving the monocytosis frequent in MCAS. Demographically, white females dominated. Median ages at symptom onset and diagnosis were 9 and 49 years, respectively (range: 0-88 and 16-92, respectively) and median time from symptom onset to diagnosis was 30 years (range: 1-85). Median numbers of comorbidities, symptoms, and family medical issues were 11, 20, and 4, respectively (range: 1-66, 2-84, and 0-33, respectively). Gastroesophageal reflux, fatigue and dermatographism were the most common comorbidity, symptom and examination finding. Abnormalities in routine laboratories were common and diverse but typically modest. The most useful diagnostic markers were heparin, prostaglandin D 2 , histamine and chromogranin A. Flow cytometric and cytokine assessments were unhelpful. Our study highlights MCAS׳s morbidity burden and challenging heterogeneity. Recognition is important given good survival and treatment prospects. Copyright © 2017 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

Increased mast cell density in haemorrhoid venous blood vessels suggests a role in pathogenesis.

PubMed

Taweevisit, M; Wisadeopas, N; Phumsuk, U; Thorner, P S

2008-12-01

Haemorrhoids are an abnormal, tortuous dilatation of the arteriovenous plexus of the anus. Although increased resting anorectal pressure is deemed to be a major initiating factor, a thorough understanding of the pathogenesis is still lacking. Mast cells, through release of granules, can affect local vessels with respect to changes in calibre, changes in permeability and thrombosis. Thus, mast cells could play a role in haemorrhoid pathophysiology, although this has not been previously investigated. 48 cases of haemorrhoids were retrospectively collected at King Chulalongkorn Memorial Hospital, with normal anorectal tissue from surgically-removed colorectal cancer serving as controls. Mast cells were identified by toluidine blue staining and quantitated around venous vessels. Mast cells around haemorrhoidal vessels were significantly more numerous than in normal specimens (p-value is less than 0.001). Similar values were found for haemorrhoids showing chronic changes and those in a more acute stage. These findings support the hypothesis that mast cells may play a role in the pathophysiology of haemorrhoids. Mast cells appear to participate equally in the early and later stages of these lesions. Mast cells are known to affect local vascular conditions through release of their chemical mediators and cytokines, and may influence haemorrhoid symptomatology and progression at this level.

Mast Cells Play No Role in the Pathogenesis of Postoperative Ileus Induced by Intestinal Manipulation

PubMed Central

Gomez-Pinilla, Pedro J.; Farro, Giovanna; Di Giovangiulio, Martina; Stakenborg, Nathalie; Némethova, Andrea; de Vries, Annick; Liston, Adrian; Feyerabend, Thorsten B.; Rodewald, Hans-Reimwer; Boeckxstaens, Guy E.; Matteoli, Gianluca

2014-01-01

Introduction Intestinal manipulation (IM) during abdominal surgery results in intestinal inflammation leading to hypomotility or ileus. Mast cell activation is thought to play a crucial role in the pathophysiology of postoperative ileus (POI). However, this conclusion was mainly drawn using mast cell-deficient mouse models with abnormal Kit signaling. These mice also lack interstitial cells of Cajal (ICC) resulting in aberrant gastrointestinal motility even prior to surgery, compromising their use as model to study POI. To avoid these experimental weaknesses we took advantage of a newly developed knock-in mouse model, Cpa3Cre/+, devoid of mast cells but with intact Kit signaling. Design The role of mast cells in the development of POI and intestinal inflammation was evaluated assessing gastrointestinal transit and muscularis externa inflammation after IM in two strains of mice lacking mast cells, i.e. KitW-sh/W-sh and Cpa3Cre/+ mice, and by use of the mast cell stabilizer cromolyn. Results KitW-sh/W-sh mice lack ICC networks and already revealed significantly delayed gastrointestinal transit even before surgery. IM did not further delay intestinal transit, but induced infiltration of myeloperoxidase positive cells, expression of inflammatory cytokines and recruitment of monocytes and neutrophils into the muscularis externa. On the contrary, Cpa3Cre/+ mice have a normal network of ICC and normal gastrointestinal. Surprisingly, IM in Cpa3Cre/+ mice caused delay in gut motility and intestinal inflammation as in wild type littermates mice (Cpa3+/+). Furthermore, treatment with the mast cell inhibitor cromolyn resulted in an inhibition of mast cells without preventing POI. Conclusions Here, we confirm that IM induced mast cell degranulation. However, our data demonstrate that mast cells are not required for the pathogenesis of POI in mice. Although there might be species differences between mouse and human, our results argue against mast cell inhibitors as a therapeutic

Genitourinary mast cells and survival

PubMed Central

Stewart, Julia M.

2015-01-01

Mast cells (MCs) are ubiquitous in the body, but they have historically been associated with allergies, and most recently with regulation of immunity and inflammation. However, it remains a puzzle why so many MCs are located in the diencephalon, which regulates emotions and in the genitourinary tract, including the bladder, prostate, penis, vagina and uterus that hardly ever get allergic reactions. A number of papers have reported that MCs have estrogen, gonadotropin and corticotropin-releasing hormone (CRH) receptors. Moreover, animal experiments have shown that diencephalic MCs increase in number during courting in doves. We had reported that allergic stimulation of nasal MCs leads to hypothalamic-pituitary adrenal (HPA) activation. Interestingly, anecdotal information indicates that female patients with mastocytosis or mast cell activation syndrome may have increased libido. Preliminary evidence also suggests that MCs may have olfactory receptors. MCs may, therefore, have been retained phylogenetically not only to “smell danger”, but to promote survival and procreation. PMID:26813805

Genitourinary mast cells and survival.

PubMed

Theoharides, Theoharis C; Stewart, Julia M

2015-10-01

Mast cells (MCs) are ubiquitous in the body, but they have historically been associated with allergies, and most recently with regulation of immunity and inflammation. However, it remains a puzzle why so many MCs are located in the diencephalon, which regulates emotions and in the genitourinary tract, including the bladder, prostate, penis, vagina and uterus that hardly ever get allergic reactions. A number of papers have reported that MCs have estrogen, gonadotropin and corticotropin-releasing hormone (CRH) receptors. Moreover, animal experiments have shown that diencephalic MCs increase in number during courting in doves. We had reported that allergic stimulation of nasal MCs leads to hypothalamic-pituitary adrenal (HPA) activation. Interestingly, anecdotal information indicates that female patients with mastocytosis or mast cell activation syndrome may have increased libido. Preliminary evidence also suggests that MCs may have olfactory receptors. MCs may, therefore, have been retained phylogenetically not only to "smell danger", but to promote survival and procreation.

Curine inhibits mast cell-dependent responses in mice.

PubMed

Ribeiro-Filho, Jaime; Leite, Fagner Carvalho; Costa, Hermann Ferreira; Calheiros, Andrea Surrage; Torres, Rafael Carvalho; de Azevedo, Carolina Trindade; Martins, Marco Aurélio; Dias, Celidarque da Silva; Bozza, Patrícia T; Piuvezam, Márcia Regina

2014-09-11

Curine is a bisbenzylisoquinoline alkaloid and the major constituent isolated from Chondrodendron platyphyllum, a plant that is used to treat inflammatory diseases in Brazilian folk medicine. This study investigates the effectiveness of curine on mast cell-dependent responses in mice. To induce mast cell-dependent responses, Swiss mice were subcutaneously sensitized with ovalbumin (OVA-12 μg/mouse) and Al(OH)3 in a 0.9% NaCl solution. Fifteen days later, the animals were challenged with OVA through different pathways. Alternatively, the animals were injected with compound 48/80 or histamine, and several parameters, including anaphylaxis, itching, edema and inflammatory mediator production, were analyzed. Promethazine, cromoglycate, and verapamil were used as control drugs, and all of the treatments were performed 1h before the challenges. Curine pre-treatment significantly inhibited the scratching behavior and the paw edema induced by either compound 48/80 or OVA, and this protective effect was comparable in magnitude with those associated with treatment with either cromoglycate or verapamil. In contrast, curine was a weak inhibitor of histamine-induced paw edema, which was completely inhibited by promethazine. Curine and verapamil significantly inhibited pleural protein extravasations and prostaglandin D2 (PGD2) and cysteinyl leukotrienes (CysLTs) production following allergen-induced pleurisy. Furthermore, like verapamil, curine inhibited the anaphylactic shock caused by either compound 48/80 or an allergen. In in vitro settings, these treatments also inhibited degranulation as well as PGD2 and CysLT production through IgE-dependent activation of the mast cell lineage RBL-2H3. Curine significantly inhibited immediate allergic reactions through mechanisms more related to mast cell stabilization and activation inhibition than interference with the pro-inflammatory effects of mast cell products. These findings are in line with the hypothesis that the alkaloid

Mast cell number, substance P and vasoactive intestinal peptide in irritable bowel syndrome with diarrhea.

PubMed

Sohn, Won; Lee, Oh Young; Lee, Sang Pyo; Lee, Kang Nyeong; Jun, Dae Won; Lee, Hang Lak; Yoon, Byung Chul; Choi, Ho Soon; Sim, Jongmin; Jang, Ki-Seok

2014-01-01

Recent studies have shown that mast cells play an important role in irritable bowel syndrome (IBS). We investigated the relationship between mast cells and the gut hormones substance P and vasoactive intestinal peptide (VIP) in irritable bowel syndrome with diarrhea (IBS-D). Colonoscopic biopsies were performed on the rectal mucosa of 43 subjects (IBS-D patients: 22, healthy volunteers: 21) diagnosed according to the Rome III criteria. Mast cells, and substance P & VIP were evaluated by quantitative immunohistology and image analysis. Mast cells were counted as tryptase-positive cells in the lamina propria, and substance P and VIP levels were expressed as percentages of total areas of staining. Mast cell counts were higher in IBS-D patients than healthy volunteers (9.6 ± 3.3 vs. 5.7 ± 2.5/high power field (HPF), p < 0.01). Substance P was also elevated (0.11 ± 0.08% vs. 0.03 ± 0.02 %, p < 0.01) while VIP was only high in women with IBS-D. Mast cell counts were positively correlated with levels of substance P & VIP in women but not men (women: r = 0.625, p < 0.01 for substance P and r = 0.651, p < 0.01 for VIP). However, mast cell counts were not correlated with IBS symptoms including abdominal pain. Mast cells are activated leading to the raised levels of substance P & VIP in IBS-D patients. However, the correlation between mast cells and levels of substance P & VIP differs according to gender.

Environmentally relevant metal and transition metal ions enhance Fc epsilon RI-mediated mast cell activation.

PubMed Central

Walczak-Drzewiecka, Aurelia; Wyczólkowska, Janina; Dastych, Jaroslaw

2003-01-01

Upon contact with allergen, sensitized mast cells release highly active proinflammatory mediators. Allergen-mediated mast cell activation is an important mechanism in the pathogenesis of atopic asthma. Asthmatic patients are especially susceptible to air pollution. Epidemiologic studies found a positive correlation between severity of symptoms among asthmatic patients and the level of particulate matter (PM) in the air. Among the constituents of PM are metals and transition metals, which could mediate some of its adverse effects on human health. We sought to determine the effect of metal and transition metal ions on allergen-mediated mast cell activation. We observed that several metal and transition metal ions activated mast cells and enhanced allergen-mediated mast cell activation. Thus, Al(3+), Cd(2+), and Sr(2+) induced release of granule-associated N-acetyl-ss-d-hexosaminidase, and Al(3+) and Ni(2+) enhanced antigen-mediated release. Metal and transition metal ions also induced significant secretion of interleukin (IL)-4 and increased antigen-mediated IL-4 secretion in mast cells. These effects of metal and transition metal ions on mast cells were observed at concentrations that do not result in direct cytotoxicity and might be relevant for environmental exposure. Thus, metals and transition metals could increase the level of allergen-mediated mast cell activation, which might be one of the mechanisms mediating exacerbation of allergen-driven asthma symptoms by air pollution. PMID:12727598

Redox regulation of mast cell histamine release in thioredoxin-1 (TRX) transgenic mice.

PubMed

Son, Aoi; Nakamura, Hajime; Kondo, Norihiko; Matsuo, Yoshiyuki; Liu, Wenrui; Oka, Shin-ichi; Ishii, Yasuyuki; Yodoi, Junji

2006-02-01

Thioredoxin-1 (TRX) is a stress-inducible redox-regulatory protein with antioxidative and anti-inflammatory effects. Here we show that the release of histamine from mast cells elicited by cross-linking of high-affinity receptor for IgE (FcepsilonRI) was significantly suppressed in TRX transgenic (TRX-tg) mice compared to wild type (WT) mice. Intracellular reactive oxygen species (ROS) of mast cells stimulated by IgE and antigen was also reduced in TRX-tg mice compared to WT mice. Whereas there was no difference in the production of cytokines (IL-6 and TNF-alpha) from mast cells in response to 2,4-dinitrophenylated bovine serum albumin (DNP-BSA) stimulation in TRX-tg and WT mice. Immunological status of TRX-tg mice inclined to T helper (Th) 2 dominant in primary immune response, although there was no difference in the population of dendritic cells (DCs) and regulatory T cells. We conclude that the histamine release from mast cells in TRX-tg mice is suppressed by inhibition of ROS generation. As ROS are involved in mast cell activation and facilitate mediator release, TRX may be a key signaling molecule regulating the early events in the IgE signaling in mast cells and the allergic inflammation.

IgE and mast cells in host defense against parasites and venoms

PubMed Central

Mukai, Kaori; Tsai, Mindy; Galli, Stephen J.

2016-01-01

IgE-dependent mast cell activation is a major effector mechanism underlying the pathology associated with allergic disorders. The most dramatic of these IgE-associated disorders is the fatal anaphylaxis which can occur in some people who have developed IgE antibodies to otherwise innocuous antigens, such as those contained in certain foods and medicines. Why would such a highly “maladaptive” immune response develop in evolution, and be retained to the present day? Host defense against parasites has long been considered the only beneficial function that might be conferred by IgE and mast cells. However, recent studies have provided evidence that, in addition to participating in host resistance to certain parasites, mast cells and IgE are critical components of innate (mast cells) and adaptive (mast cells and IgE) immune responses that can enhance host defense against the toxicity of certain arthropod and animal venoms, including enhancing the survival of mice injected with such venoms. Yet, in some people, developing IgE antibodies to insect or snake venoms puts them at risk for having a potentially fatal anaphylactic reaction upon subsequent exposure to such venoms. Delineating the mechanisms underlying beneficial versus detrimental innate and adaptive immune responses associated with mast cell activation and IgE is likely to enhance our ability to identify potential therapeutic targets in such settings, not only for reducing the pathology associated with allergic disorders but perhaps also for enhancing immune protection against pathogens and animal venoms. PMID:27225312

IgE and mast cells in host defense against parasites and venoms.

PubMed

Mukai, Kaori; Tsai, Mindy; Starkl, Philipp; Marichal, Thomas; Galli, Stephen J

2016-09-01

IgE-dependent mast cell activation is a major effector mechanism underlying the pathology associated with allergic disorders. The most dramatic of these IgE-associated disorders is the fatal anaphylaxis which can occur in some people who have developed IgE antibodies to otherwise innocuous antigens, such as those contained in certain foods and medicines. Why would such a highly "maladaptive" immune response develop in evolution and be retained to the present day? Host defense against parasites has long been considered the only beneficial function that might be conferred by IgE and mast cells. However, recent studies have provided evidence that, in addition to participating in host resistance to certain parasites, mast cells and IgE are critical components of innate (mast cells) and adaptive (mast cells and IgE) immune responses that can enhance host defense against the toxicity of certain arthropod and animal venoms, including enhancing the survival of mice injected with such venoms. Yet, in some people, developing IgE antibodies to insect or snake venoms puts them at risk for having a potentially fatal anaphylactic reaction upon subsequent exposure to such venoms. Delineating the mechanisms underlying beneficial versus detrimental innate and adaptive immune responses associated with mast cell activation and IgE is likely to enhance our ability to identify potential therapeutic targets in such settings, not only for reducing the pathology associated with allergic disorders but perhaps also for enhancing immune protection against pathogens and animal venoms.

Operationalizing the telecoupling framework for migratory species using the spatial subsidies approach to examine ecosystem services provided by Mexican free-tailed bats

USGS Publications Warehouse

Lopez Hoffman, Laura; Diffendorfer, James E.; Widerholt, Ruscena; Thogmartin, Wayne E.; McCraken, Gary; Medellin, Rodrigo; Bagstad, Kenneth J.; Russell, Amy; Semmens, Darius J.

2017-01-01

Drivers of environmental change in one location can have profound effects on ecosystem services and human well-being in distant locations, often across international borders. The telecoupling provides a conceptual framework for describing these interactions—for example, locations can be defined as sending areas (sources of flows of ecosystem services, energy, or information) or receiving areas (recipients of flows). However, the ability to quantify feedbacks between ecosystem change in one area and societal benefits in other areas requires analytical approaches. We use spatial subsidies—an approach developed to measure the degree to which a migratory species’ ability to provide services in one location depends on habitat in another location—as an example of how telecoupling can be operationalized. Using the cotton pest control and ecotourism services of Mexican free-tailed bats as an example, we determined that of the 16 states in the United States and Mexico where the species resides, three states (Texas, New Mexico, and Colorado) are receiving areas, while the rest of the states are sending areas. In addition, the magnitude of spatial subsidy can be used as an indicator of the degree to which different locations are telecoupled to other locations. In this example, the Mexican free-tailed bat ecosystem services to cotton production and ecotourism in Texas and New Mexico are heavily dependent on winter habitat in four states in central and southern Mexico. In sum, spatial subsidies can be used to operationalize the telecoupling conceptual framework by identifying sending and receiving areas, and by indicating the degree to which locations are telecoupled to other locations.

Role of mast cells in bronchial contraction in nonallergic obstructive lung pathology.

PubMed

Kuzubova, Nataliya A; Lebedeva, Elena S; Titova, Olga N; Fedin, Anatoliy N; Dvorakovskaya, Ivetta V

2017-01-01

The role of mast cells in contractile bronchial smooth muscle activity has been evaluated in a model of chronic obstructive pulmonary disease induced in rats that were intermittently exposed to nitrogen dioxide (NO 2 ) for 60 days. Starting from the 31st day, one group of rats inhaled sodium cromoglycate before exposure to NO 2 to stabilize mast cell membranes. The second group (control) was not treated. Isometric smooth muscle contraction was analysed in isolated bronchial samples in response to nerve and smooth muscle stimulation. Histological analysis revealed large numbers of mast cells in lung tissue of COPD model rats. The inhibition of mast cell degranulation by sodium cromoglycate prevented the development of nerve-stimulated bronchial smooth muscle hyperactivity in COPD model rats. Histamine or adenosine-induced hyperactivity on nerve stimulation was also inhibited by sodium cromoglycate in bronchial smooth muscle in both control and COPD model rats. This suggests that the mechanism of contractile activity enhancement of bronchial wall smooth muscle cells may be mediated through the activation of resident mast cells transmembrane adenosine receptors resulting in their partial degranulation, with the released histamine acting upon histamine H1-receptors which trigger reflex pathways via intramural ganglion neurons.

Quantitative analysis of mast cell count and density in chronic periodontal disease.

PubMed

Rathod, Surekha; Raj, Anubha; Wanikar, Ishita

2018-01-01

Mast cells play a crucial role in activation of acquired immune response to inflammatory conditions of periodontal diseases. They promote inflammation by releasing pro-inflammatory mediators and bring about angiogenesis, degeneration of the extracellular matrix, and tissue remodeling. Since there is little literature regarding the role of mast cells in periodontitis, the present study was aimed to evaluate mast cell count (MCC) and density in periodontitis. A total of eighty participants, Group I ( n = 40) healthy participants and Group II ( n = 40) participants with moderate chronic periodontitis, were included in the study. Tissue samples of 5 micron were obtained from each participant and were fixed in 10% formalin. Inflammation assessment was carried out after staining the sections with hematoxylin/eosin (H and E) followed by toluidine blue and mast cells were counted. MCC in healthy group (1.32 ± 0.43) was significantly smaller than periodontitis group (10.28 ± 1.15) and also mast cell density in healthy group (98.08 ± 37.40) was smaller than periodontitis group (803.43 ± 89.94) with P < 0.0001. It could be concluded that participants with chronic periodontitis have a higher MCC and density when compared with healthy participants.

Copper Regulates Maturation and Expression of an MITF:Tryptase Axis in Mast Cells.

PubMed

Hu Frisk, Jun Mei; Kjellén, Lena; Kaler, Stephen G; Pejler, Gunnar; Öhrvik, Helena

2017-12-15

Copper has previously been implicated in the regulation of immune responses, but the impact of this metal on mast cells is poorly understood. In this article, we address this issue and show that copper starvation of mast cells causes increased granule maturation, as indicated by higher proteoglycan content, stronger metachromatic staining, and altered ultrastructure in comparison with nontreated cells, whereas copper overload has the opposite effects. In contrast, copper status did not impact storage of histamine in mast cells, nor did alterations in copper levels affect the ability of mast cells to degranulate in response to IgER cross-linking. A striking finding was decreased tryptase content in mast cells with copper overload, whereas copper starvation increased tryptase content. These effects were associated with corresponding shifts in tryptase mRNA levels, suggesting that copper affects tryptase gene regulation. Mechanistically, we found that alterations in copper status affected the expression of microphthalmia-associated transcription factor, a transcription factor critical for driving tryptase expression. We also found evidence supporting the concept that the effects on microphthalmia-associated transcription factor are dependent on copper-mediated modulation of MAPK signaling. Finally, we show that, in MEDNIK syndrome, a condition associated with low copper levels and a hyperallergenic skin phenotype, including pruritis and dermatitis, the number of tryptase-positive mast cells is increased. Taken together, our findings reveal a hitherto unrecognized role for copper in the regulation of mast cell gene expression and maturation. Copyright © 2017 by The American Association of Immunologists, Inc.

Interplay between mast cells, enterochromaffin cells, and sensory signaling in the aging human bowel.

PubMed

Yu, Y; Daly, D M; Adam, I J; Kitsanta, P; Hill, C J; Wild, J; Shorthouse, A; Grundy, D; Jiang, W

2016-10-01

Advanced age is associated with a reduction in clinical visceral pain perception. However, the underlying mechanisms remain largely unknown. Previous studies have suggested that an abnormal interplay between mast cells, enterochromaffin (EC) cells, and afferent nerves contribute to nociception in gastrointestinal disorders. The aim of this study was to investigate how aging affects afferent sensitivity and neuro-immune association in the human bowel. Mechanical and chemical sensitivity of human bowel afferents were examined by ex vivo afferent nerve recordings. Age-related changes in the density of mast cells, EC cells, sensory nerve terminals, and mast cell-nerve micro-anatomical association were investigated by histological and immune staining. Human afferents could be broadly classified into subpopulations displaying mechanical and chemical sensitivity, adaptation, chemo-sensitization, and recruitment. Interestingly human bowel afferent nerve sensitivity was attenuated with age. The density of substance P-immunoreactive (SP-IR) nerve varicosities was also reduced with age. In contrast, the density of ileal and colonic mucosal mast cells was increased with age, as was ileal EC cell number. An increased proportion of mast cells was found in close apposition to SP-IR nerves. Afferent sensitivity in human bowel was reduced with advancing age. Augmentation of mast cells and EC cell numbers and the mast cell-nerve association suggest a compensatory mechanism for sensory neurodegeneration. © 2016 The Authors. Neurogastroenterology & Motility Published by John Wiley & Sons Ltd.

Zinc Oxide Nanoparticles Demoted MDM2 Expression to Suppress TSLP-Induced Mast Cell Proliferation.

PubMed

Kim, Min-Ho; Jeong, Hyun-Ja

2016-03-01

Activation of murine double minute 2 (MDM2) through thymic stromal lymphopoietin (TSLP)-induced signal transducers and activators of transcription (STAT6) phosphorylation plays a critical role in proliferation and survival of mast cells. Previously, we reported that zinc oxide nanoparticles (ZnO-NP) effectively decrease the mast cell-mediated allergic inflammatory reactions. Here, we evaluated the effect of ZnO-NP on TSLP-induced proliferation of mast cells. ZnO-NP significantly reduced the number of BrdU-incorporating mast cells increased by TSLP. ZnO-NP decreased the expression of MDM2 through the blockade of STAT6 phosphorylation. TSLP increased the production and mRNA expression of interleukin-13 (a growth factor of mast cells), its increase was significantly decreased by ZnO-NP (10 μg/mL). ZnO-NP induced the down-regulation of Bcl2 (an anti-apoptotic factor) and up-regulation of Bax (an apoptotic factor) through the stabilization of p53 protein. However, ZnO-NP has no effect on caspase-3 activation, cytochrome c release into cytosol, and apoptosis-inducing factor translocation into nucleus in TSLP-stimulated cells. The results of the present study demonstrated that ZnO-NP inhibited the proliferation of mast cells through the regulation of MDM2 and p53 protein levels. These finding suggest that ZnO-NP could be improved mast cell-mediated various diseases.

Induction of mast cell accumulation by chymase via an enzymatic activity- and intercellular adhesion molecule-1-dependent mechanism.

PubMed

Zhang, Huiyun; Wang, Junling; Wang, Ling; Zhan, Mengmeng; Li, Shigang; Fang, Zeman; Xu, Ciyan; Zheng, Yanshan; He, Shaoheng

2018-02-01

Chymase is a unique, abundant secretory product of mast cells and a potent chemoattractant for eosinophils, monocytes and neutrophils, but little is known of its influence on mast cell accumulation. A mouse peritoneal inflammation model, cell migration assay and flowcytometry analysis, were used to investigate the role of chymase in recruiting mast cells. Chymase increased, by up to 5.4-fold, mast cell numbers in mouse peritoneum. Inhibitors of chymase, heat-inactivation of the enzyme, sodium cromoglycate and terfenadine, and pretreatment of mice with anti-intercellular adhesion molecule 1, anti-L-selectin, anti-CD11a and anti-CD18 antibodies dramatically diminished the chymase-induced increase in mast cell accumulation. These findings indicate that this effect of chymase is dependent on its enzymatic activity and activation of adhesion molecules. In addition, chymase provoked a significant increase in 5-HT and eotaxin release (up to 1.8- and 2.2-fold, respectively) in mouse peritoneum. Since 5-HT, eotaxin and RANTES can induce marked mast cell accumulation, these indirect mechanisms may also contribute to chymase-induced mast cell accumulation. Moreover, chymase increased the trans-endothelium migration of mast cells in vitro indicating it also acts as a chemoattractant. The finding that mast cells accumulate in response to chymase implies further that chymase is a major pro-inflammatory mediator of mast cells. This effect of chymase, a major product of mast cell granules, suggests a novel self-amplification mechanism for mast cell accumulation in allergic inflammation. Mast cell stabilizers and inhibitors of chymase may have potential as a treatment of allergic disorders. © 2017 The British Pharmacological Society.

Mast cell chymase reduces the toxicity of Gila monster venom, scorpion venom, and vasoactive intestinal polypeptide in mice

PubMed Central

Akahoshi, Mitsuteru; Song, Chang Ho; Piliponsky, Adrian M.; Metz, Martin; Guzzetta, Andrew; Åbrink, Magnus; Schlenner, Susan M.; Feyerabend, Thorsten B.; Rodewald, Hans-Reimer; Pejler, Gunnar; Tsai, Mindy; Galli, Stephen J.

2011-01-01

Mast cell degranulation is important in the pathogenesis of anaphylaxis and allergic disorders. Many animal venoms contain components that can induce mast cell degranulation, and this has been thought to contribute to the pathology and mortality caused by envenomation. However, we recently reported evidence that mast cells can enhance the resistance of mice to the venoms of certain snakes and that mouse mast cell–derived carboxypeptidase A3 (CPA3) can contribute to this effect. Here, we investigated whether mast cells can enhance resistance to the venom of the Gila monster, a toxic component of that venom (helodermin), and the structurally similar mammalian peptide, vasoactive intestinal polypeptide (VIP). Using 2 types of mast cell–deficient mice, as well as mice selectively lacking CPA3 activity or the chymase mouse mast cell protease-4 (MCPT4), we found that mast cells and MCPT4, which can degrade helodermin, can enhance host resistance to the toxicity of Gila monster venom. Mast cells and MCPT4 also can limit the toxicity associated with high concentrations of VIP and can reduce the morbidity and mortality induced by venoms from 2 species of scorpions. Our findings support the notion that mast cells can enhance innate defense by degradation of diverse animal toxins and that release of MCPT4, in addition to CPA3, can contribute to this mast cell function. PMID:21926462

Mars Weather-Station Tools on Rover Mast

NASA Image and Video Library

2015-04-13

The Rover Environmental Monitoring Station (REMS) on NASA's Curiosity Mars rover includes temperature and humidity sensors mounted on the rover's mast. One of the REMS booms extends to the left from the mast in this view. Spain provided REMS to NASA's Mars Science Laboratory Project. The monitoring station has provided information about air pressure, relative humidity, air temperature, ground temperature, wind and ultraviolet radiation in all Martian seasons and at all times of day or night. This view is a detail from a January 2015 Curiosity self-portrait. The self-portrait, at PIA19142, was assembled from images taken by Curiosity's Mars Hand Lens Imager. http://photojournal.jpl.nasa.gov/catalog/PIA19164

LQC control for the Mini-Mast experiment

NASA Technical Reports Server (NTRS)

Montgomery, R. C.; Ghosh, D.

1988-01-01

The Mini-Mast system is briefly reviewed, and results of a simulation study of the LQG control for the Mini-Mast experiment are reported. In particular, attention is given to problems and limitations related to the testing of control laws using reaction mass actuators, such as accounting for force and stroke limits of these devices. The local controller used in the study and the algorithm for converting the force commands of the LQG algorithm to position commands for the reaction mass device are described. It is shown that the LQG generated damping is reduced when a local controller is used and the position command is not saturated; it drops still further when the position command is saturated.

Near-tail reconnection as the cause of cometary tail disconnections

NASA Technical Reports Server (NTRS)

Russell, C. T.; Saunders, M. A.; Phillips, J. L.; Fedder, J. A.

1986-01-01

In a cometary tail disconnection event the plasma tail appears to separate from the coma and to accelerate away from it. As this occurs a new tail begins to form. It is proposed that these disconnections arise in a manner analogous to geomagnetic substorms, i.e., by the formation of a strongly reconnecting region in the near tail that forms a magnetic island in the coma and ejects the plasma tail by strengthening the magnetic 'slingshot' within the tail. This reconnection process may be triggered by several different processes, such as interplanetary shocks or variations in the Alfven Mach number.

The Mechanism of Anaphylaxis: Specificity of Antigen-Induced Mast Cell Damage in Anaphylaxis in the Guinea Pig

PubMed Central

Humphrey, J. H.; Mota, I.

1959-01-01

Mast cell damage, characterized by loss of granules, occurs when the tissues of sensitized guinea pigs are brought into contact with antigen in vivo or in vitro. Quantitative studies on the mesenteries of passively sensitized guinea pigs show that the mast cell response to antigen is well correlated with the development of anaphylactic shock. After multiple sensitization contact with different antigens caused cumulative, but not complete, disappearance of mast cells. Antigen-antibody interactions, in which antisera were from species which do not sensitize guinea pigs passively for anaphylaxis, did not cause mast cell damage. Reversed passive anaphylaxis and mast cell damage were elicited when the antigen was a suitable γ-globulin, but not an albumin. Antiserum against homologous γ-globulin causes typical anaphylaxis and mast cell degranulation, whereas antiserum against Forssman antigen causes capillary damage without mast cell changes, and antiserum against homologous albumin is ineffective. These findings can be explained by the hypothesis that mast cell damage occurs as a result of antigen-antibody interaction, when one of the reagents is reversibly adsorbed at the mast cell surface, and when they are together capable of activating some process or agent whose further action depends upon the metabolic integrity of the cells. PMID:13640678

Mast cells are dispensable for normal and activin-promoted wound healing and skin carcinogenesis.

PubMed

Antsiferova, Maria; Martin, Caroline; Huber, Marcel; Feyerabend, Thorsten B; Förster, Anja; Hartmann, Karin; Rodewald, Hans-Reimer; Hohl, Daniel; Werner, Sabine

2013-12-15

The growth and differentiation factor activin A is a key regulator of tissue repair, inflammation, fibrosis, and tumorigenesis. However, the cellular targets, which mediate the different activin functions, are still largely unknown. In this study, we show that activin increases the number of mature mast cells in mouse skin in vivo. To determine the relevance of this finding for wound healing and skin carcinogenesis, we mated activin transgenic mice with CreMaster mice, which are characterized by Cre recombinase-mediated mast cell eradication. Using single- and double-mutant mice, we show that loss of mast cells neither affected the stimulatory effect of overexpressed activin on granulation tissue formation and reepithelialization of skin wounds nor its protumorigenic activity in a model of chemically induced skin carcinogenesis. Furthermore, mast cell deficiency did not alter wounding-induced inflammation and new tissue formation or chemically induced angiogenesis and tumorigenesis in mice with normal activin levels. These findings reveal that mast cells are not major targets of activin during wound healing and skin cancer development and also argue against nonredundant functions of mast cells in wound healing and skin carcinogenesis in general.

Influence of mass moment of inertia on normal modes of preloaded solar array mast

NASA Technical Reports Server (NTRS)

Armand, Sasan C.; Lin, Paul

1992-01-01

Earth-orbiting spacecraft often contain solar arrays or antennas supported by a preloaded mast. Because of weight and cost considerations, the structures supporting the spacecraft appendages are extremely light and flexible; therefore, it is vital to investigate the influence of all physical and structural parameters that may influence the dynamic behavior of the overall structure. The study primarily focuses on the mast for the space station solar arrays, but the formulations and the techniques developed in this study apply to any large and flexible mast in zero gravity. Furthermore, to determine the influence on the circular frequencies, the mass moment of inertia of the mast was incorporated into the governing equation of motion for bending. A finite element technique (MSC/NASTRAN) was used to verify the formulation. Results indicate that when the mast is relatively flexible and long, the mass moment inertia influences the circular frequencies.

Mast cell inhibition as a therapeutic approach in fibrodysplasia ossificans progressiva (FOP).

PubMed

Brennan, Tracy A; Lindborg, Carter M; Bergbauer, Christian R; Wang, Haitao; Kaplan, Frederick S; Pignolo, Robert J

2018-04-01

Episodic flare-ups of fibrodysplasia ossificans progressiva (FOP) are characterized clinically by severe, often posttraumatic, connective tissue swelling and intramuscular edema, followed histologically by an intense and highly angiogenic fibroproliferative reaction. This early inflammatory and angiogenic fibroproliferative response is accompanied by the presence of abundant mast cells far in excess of other reported myopathies. Using an injury-induced, constitutively-active transgenic mouse model of FOP we show that mast cell inhibition by cromolyn, but not aprepitant, results in a dramatic reduction of heterotopic ossification. Cromolyn, but not aprepitant, significantly decreases the total number of mast cells in FOP lesions. Furthermore, cromolyn specifically diminishes the number of degranulating and resting degranulated mast cells in pre-osseous lesions. This work demonstrates that consideration of FOP as a type of localized mastocytosis may offer new therapeutic interventions for treatment of this devastating condition. Copyright © 2017 Elsevier Inc. All rights reserved.

Physiological relevance of LL-37 induced bladder inflammation and mast cells.

PubMed

Oottamasathien, Siam; Jia, Wanjian; Roundy, Lindsi McCoard; Zhang, Jianxing; Wang, Li; Ye, Xiangyang; Hill, A Cameron; Savage, Justin; Lee, Wong Yong; Hannon, Ann Marie; Milner, Sylvia; Prestwich, Glenn D

2013-10-01

We established the physiological relevance of LL-37 induced bladder inflammation. We hypothesized that 1) human urinary LL-37 is increased in pediatric patients with spina bifida, 2) LL-37 induced inflammation occurs in our mouse model via urothelial binding and is dose dependent and 3) LL-37 induced inflammation involves mast cells. To test our first hypothesis, we obtained urine samples from 56 pediatric patients with spina bifida and 22 normal patients. LL-37 was measured by enzyme-linked immunosorbent assay. Our second hypothesis was tested in C57Bl/6 mice challenged with 7 LL-37 concentrations intravesically for 1 hour. At 24 hours tissues were examined histologically and myeloperoxidase assay was done to quantitate inflammation. In separate experiments fluorescent LL-37 was instilled and tissues were obtained immediately (time = 0) and at 24 hours (time = 24). To test our final hypothesis, we performed immunohistochemistry for mast cell tryptase and evaluated 5 high power fields per bladder to determine the mean number of mast cells per mm(2). Urinary LL-37 was 89-fold higher in patients with spina bifida. Mouse LL-37 dose escalation experiments revealed increased inflammation at higher LL-37 concentrations. Fluorescent LL-37 demonstrated global urothelial binding at time = 0 but was not visible at time = 24. Immunohistochemistry for tryptase revealed mast cell infiltration in all tissue layers. At higher concentrations the LL-37 challenge led to significantly greater mast cell infiltration. Urinary LL-37 was significantly increased in pediatric patients with spina bifida. To our knowledge we report for the first time that LL-37 can elicit profound, dose dependent bladder inflammation involving the urothelium. Finally, inflammation propagation involves mast cells. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Physiological Relevance of LL-37 Induced Bladder Inflammation and Mast Cells

PubMed Central

Roundy, Lindsi McCoard; Zhang, Jianxing; Wang, Li; Ye, Xiangyang; Hill, A. Cameron; Savage, Justin; Lee, Wong Yong; Hannon, Ann Marie; Milner, Sylvia; Prestwich, Glenn D.

2014-01-01

Purpose We established the physiological relevance of LL-37 induced bladder inflammation. We hypothesized that 1) human urinary LL-37 is increased in pediatric patients with spina bifida, 2) LL-37 induced inflammation occurs in our mouse model via urothelial binding and is dose dependent and 3) LL-37 induced inflammation involves mast cells. Materials and Methods To test our first hypothesis, we obtained urine samples from 56 pediatric patients with spina bifida and 22 normal patients. LL-37 was measured by enzyme-linked immunosorbent assay. Our second hypothesis was tested in C57Bl/6 mice challenged with 7 LL-37 concentrations intravesically for 1 hour. At 24 hours tissues were examined histologically and myeloperoxidase assay was done to quantitate inflammation. In separate experiments fluorescent LL-37 was instilled and tissues were obtained immediately (time = 0) and at 24 hours (time = 24). To test our final hypothesis, we performed immunohistochemistry for mast cell tryptase and evaluated 5 high power fields per bladder to determine the mean number of mast cells per mm2. Results Urinary LL-37 was 89-fold higher in patients with spina bifida. Mouse LL-37 dose escalation experiments revealed increased inflammation at higher LL-37 concentrations. Fluorescent LL-37 demonstrated global urothelial binding at time = 0 but was not visible at time = 24. Immunohistochemistry for tryptase revealed mast cell infiltration in all tissue layers. At higher concentrations the LL-37 challenge led to significantly greater mast cell infiltration. Conclusions Urinary LL-37 was significantly increased in pediatric patients with spina bifida. To our knowledge we report for the first time that LL-37 can elicit profound, dose dependent bladder inflammation involving the urothelium. Finally, inflammation propagation involves mast cells. PMID:23313203

Challenges and Best Practices for the Curation and Publication of Long-Tail Data with GFZ Data Services

NASA Astrophysics Data System (ADS)

Elger, Kirsten; Ulbricht, Damian; Bertelmann, Roland

2017-04-01

involvement of the data curator, especially regarding the data description. Here we will introduce best practices for the publication of long-tail data that are helping to reduce the individual effort, improve the quality of the data description. The data repository of GFZ Data Services, which is hosted at GFZ German Research Centre for Geosciences in Potsdam, is a domain-specific data repository for geosciences. In addition to large dynamic datasets from different disciplines, it has a large focus on the DOI-referenced publication of long-tail data with the aim to reach a high grade of reusability through a comprehensive data description and in the same time provide and distribute standardised, machine actionable metadata for data discovery (FAIR data). The development of templates for data reports, metadata provision by scientists via an XML Metadata Editor and discipline-specific DOI landing pages are helping both, the data curators to handle all kinds of datasets and enabling the scientists, i.e. user, to quickly decide whether a published dataset is fulfilling their needs. In addition, GFZ Data Services have developed DOI-registration services for several international networks (e.g. ICGEM, World Stress Map, IGETS, etc.). In addition, we have developed project-or network-specific designs of the DOI landing pages with the logo or design of the networks or project

Within-population spatial synchrony in mast seeding of North American oaks.

Treesearch

A.V. Liebhold; M. Sork; O.N. Peltonen; Westfall R. Bjørnstad; J. Elkinton; M. H. J. Knops

2004-01-01

Mast seeding, the synchronous production of large crops of seeds, has been frequently documented in oak species. In this study we used several North American oak data-sets to quantify within-stand (10 km) synchrony in mast dynamics. Results indicated that intraspecific synchrony in seed production always exceeded interspecific synchrony and was essentially constant...

Flight Services and Aircraft Access: Active Flow Control Vertical Tail and Insect Accretion and Mitigation Flight Test

NASA Technical Reports Server (NTRS)

Whalen, Edward A.

2016-01-01

This document serves as the final report for the Flight Services and Aircraft Access task order NNL14AA57T as part of NASA Environmentally Responsible Aviation (ERA) Project ITD12A+. It includes descriptions of flight test preparations and execution for the Active Flow Control (AFC) Vertical Tail and Insect Accretion and Mitigation (IAM) experiments conducted on the 757 ecoDemonstrator. For the AFC Vertical Tail, this is the culmination of efforts under two task orders. The task order was managed by Boeing Research & Technology and executed by an enterprise-wide Boeing team that included Boeing Research & Technology, Boeing Commercial Airplanes, Boeing Defense and Space and Boeing Test and Evaluation. Boeing BR&T in St. Louis was responsible for overall Boeing project management and coordination with NASA. The 757 flight test asset was provided and managed by the BCA ecoDemonstrator Program, in partnership with Stifel Aircraft Leasing and the TUI Group. With this report, all of the required deliverables related to management of this task order have been met and delivered to NASA as summarized in Table 1. In addition, this task order is part of a broader collaboration between NASA and Boeing.

Mast cell inflammasome activity in the meninges regulates EAE disease severity.

PubMed

Russi, Abigail E; Walker-Caulfield, Margaret E; Brown, Melissa A

2018-04-01

Inflammasomes are multiprotein complexes that assemble in response to microbial and other danger signals and regulate the secretion of biologically active IL-1β and IL-18. Although they are important in protective immunity against bacterial, viral and parasitic infections, aberrant inflammasome activity promotes chronic inflammation associated with autoimmune disease. Inflammasomes have been described in many immune cells, but the majority of studies have focused on their activity in macrophages. Here we discuss an important role for mast cell-inflammasome activity in EAE, the rodent model of multiple sclerosis, a CNS demyelinating disease. We review our evidence that mast cells in the meninges, tissues that surround the brain and spinal cord, interact with infiltrating myelin-specific T cells in early disease. This interaction elicits IL-1β expression by mast cells, which in turn, promotes GM-CSF expression by T cells. In view of the essential role that GM-CSF plays in T cell encephalitogenicity, we propose this mast cell-T cell crosstalk in the meninges is critical for EAE disease development. Copyright © 2016 Elsevier Inc. All rights reserved.

Initial Effects of Reproduction Cutting Treatments on Residual Hard Mast Production in the Ouachita Mountains

Treesearch

Roger W. Perry; Ronald E. Thill

2003-01-01

We compared indices of total hard mast production (oak and hickory combined) in 20, second-growth, pine-hardwood stands under five treatments to determine the effects of different reproduction treatments on mast production in the Ouachita Mountains. We evaluated mast production in mature unharvested controls and stands under four reproduction cutting methods (single-...

Eigensystem realization algorithm modal identification experiences with mini-mast

NASA Technical Reports Server (NTRS)

Pappa, Richard S.; Schenk, Axel; Noll, Christopher

1992-01-01

This paper summarizes work performed under a collaborative research effort between the National Aeronautics and Space Administration (NASA) and the German Aerospace Research Establishment (DLR, Deutsche Forschungsanstalt fur Luft- und Raumfahrt). The objective is to develop and demonstrate system identification technology for future large space structures. Recent experiences using the Eigensystem Realization Algorithm (ERA), for modal identification of Mini-Mast, are reported. Mini-Mast is a 20 m long deployable space truss used for structural dynamics and active vibration-control research at the Langley Research Center. A comprehensive analysis of 306 frequency response functions (3 excitation forces and 102 displacement responses) was performed. Emphasis is placed on two topics of current research: (1) gaining an improved understanding of ERA performance characteristics (theory vs. practice); and (2) developing reliable techniques to improve identification results for complex experimental data. Because of nonlinearities and numerous local modes, modal identification of Mini-Mast proved to be surprisingly difficult. Methods were available, ERA, for obtaining detailed, high-confidence results.

Proteome analysis identifies L1CAM/CD171 and DPP4/CD26 as novel markers of human skin mast cells.

PubMed

Gschwandtner, M; Paulitschke, V; Mildner, M; Brunner, P M; Hacker, S; Eisenwort, G; Sperr, W R; Valent, P; Gerner, C; Tschachler, E

2017-01-01

The function of skin mast cells has been well documented in IgE-mediated allergic reactions, whereas other mast cell functions are poorly defined. This study aimed at identifying novel mast cell proteins by proteome analysis of primary human skin mast cells. The proteome of skin mast cells was compared to other cell types and analyzed using bioinformatics. The expression and function of two proteins hitherto not described in skin mast cells was investigated in isolated mast cells as well as in mast cells in situ. Within the mast cell proteome, we identified 49 highly expressed proteins previously not described in mast cells; 21 of these proteins were found to be selectively expressed in mast cells. Two proteins, the neural cell adhesion molecule L1 and dipeptidyl peptidase 4, were further studied. L1 was found to be highly expressed in mast cells in normal, psoriasis, and mastocytosis skin. Dipeptidyl peptidase 4 was found to be expressed in mast cells in normal, psoriasis, and mastocytosis skin as well as in bone marrow mast cells in patients with systemic mastocytosis. In normal skin, mast cells were identified as a major source of dipeptidyl peptidase 4 and we also found that skin mast cells and fibroblasts secrete an active form of this enzyme. In a systematic proteomics approach we identified two novel mast cell proteins potentially relevant to skin homeostasis: neural cell adhesion molecule L1 and dipeptidyl peptidase 4. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

An assessment of mast cells and myofibroblasts in denture-induced fibrous hyperplasia.

PubMed

Kiuchi, Misa; Yamamura, Takashi; Okudera, Michisato; Souksavanh, Vongsa; Ishigami, Tomohiko; Iwase, Takashi; Warnakulasuriya, Saman; Komiyama, Kazuo

2014-01-01

The pathogenesis of denture-induced fibrous hyperplasias has not been examined in detail to explain how tissue injury results in fibrous hyperplasia of the oral mucosa. We examined the presence of mast cells and myofibroblasts in 33 denture-induced fibrous hyperplasias (DIFH) compared with 10 healthy gingival tissues. The parameters examined included mast cell numbers, tissue distribution, degranulation, and cell subtypes using immunohistochemistry. The presence of myofibroblasts and their likely origin was also examined by double immunofluorescense staining. Furthermore, we investigated the synthesis of osteopontin and TGF-β, considered to be involved in the transformation of a fibroblast to a myofibroblast. The results demonstrated that the mast cell numbers are significantly increased in the DIFH compared with non-disease controls. The mast cell localization in lesions was higher in the superficial areas with inflammatory cell infiltration compared with the deep fibrotic area (P < 0.01). The number of tryptase-positive mast cells was significantly higher compared with chymase-positive ones. The TGF-β- or osteopontin-positive cell infiltration into the lesion was found in high numbers. The presence of myofibroblasts was identified in 14 of 33 cases (42%), and some of these cells showed apoptosis when assessed by the TUNEL assay. On the survey of the origin of myofibroblasts, results showed αSMA and vimentin positivity indicating these transformed from fibroblasts. These results are the first to show that mast cells and myofibroblasts can be detected in DIFH, indicating important roles of these cells in the pathogenesis of this lesion. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A human lung mast cell chymotrypsin-like enzyme. Identification and partial characterization.

PubMed

Wintroub, B U; Kaempfer, C E; Schechter, N M; Proud, D

1986-01-01

We have used a high performance liquid chromatography assay, which detects chymotryptic cleavage of the phe8-his9 bond of angiotensin I to yield angiotensin II, in order to examine human lung mast cells for the presence of chymotryptic activity. Mast cells, purified from human lung by enzymatic dispersion, countercurrent elutriation, and Percoll gradient centrifugation, were lysed or challenged with goat anti-human IgE. In multiple experiments angiotensin II-converting activity was detected in lysates of 10-99% pure mast cell preparations. Regression analysis of net percent release values of histamine and the angiotensin I-converting activity from dose-response experiments demonstrated a correlation between the two parameters, indicating that the chymotrypsin-like enzyme is a constituent of the mast cell secretory granule. The chymotryptic activity was completely inhibited by 10(-3) M phenylmethylsulfonylfluoride but not by 10(-3) M Captopril, and the pH optimum of activity was 7.5-9.5. Gel filtration of released material separated the activity from tryptase and demonstrated an approximate molecular weight of 30-35,000. The mast cell enzyme, like a human skin chymotrypsin-like proteinase, can be distinguished from leukocyte cathepsin G by lack of susceptibility to inhibition by bovine pancreatic trypsin inhibitor. Thus, an enzyme with limited chymotryptic specificity is present in human lung mast cells. The Michaelis constant of the enzyme for angiotensin I of 6.0 X 10(-5) M is similar to that of endothelial cell angiotensin-converting enzyme and is consistent with a reaction of physiologic importance.

Substance P induces adverse myocardial remodelling via a mechanism involving cardiac mast cells.

PubMed

Meléndez, Giselle C; Li, Jianping; Law, Brittany A; Janicki, Joseph S; Supowit, Scott C; Levick, Scott P

2011-12-01

Substance P and neurokinin A (NKA) are sensory nerve neuropeptides encoded by the TAC1 gene. Substance P is a mast cell secretagogue and mast cells are known to play a role in adverse myocardial remodelling. Therefore, we wondered whether substance P and/or NKA modulates myocardial remodelling via a mast cell-mediated mechanism. Volume overload was induced by aortocaval fistula in TAC1(-/-) mice and their respective wild types. Left ventricular internal diameter of wild-type (WT) fistulas increased by 31.9%; this was prevented in TAC1(-/-) mice (4.2%). Matrix metalloproteinase (MMP) activity was significantly increased in WT fistula mice and was prevented in TAC1(-/-) mice. Myocardial collagen volume fraction was decreased in WT fistula mice; this collagen degradation was not observed in the TAC1(-/-) group. There were no significant differences between any groups in tumour necrosis factor (TNF)-α or cell death. Cardiac mast cells were isolated from rat hearts and stimulated with substance P or NKA. We found that these cells degranulated only to substance P, via the neurokinin-1 receptor. To determine the effect of substance P on mast cells in vivo, volume overload was created in Sprague-Dawley rats treated with the NK-1 receptor antagonist L732138 (5 mg/kg/day) for a period of 3 days. L732138 prevented: (i) increases in cardiac mast cell density; (ii) increased myocardial TNF-α; and (iii) collagen degradation. Our studies suggest that substance P may be important in mediating adverse myocardial remodelling secondary to volume overload by activating cardiac mast cells, leading to increased TNF-α and MMP activation with subsequent degradation of the extracellular matrix.

The clinical and molecular diversity of mast cell leukemia with or without associated hematologic neoplasm

PubMed Central

Jawhar, Mohamad; Schwaab, Juliana; Meggendorfer, Manja; Naumann, Nicole; Horny, Hans-Peter; Sotlar, Karl; Haferlach, Torsten; Schmitt, Karla; Fabarius, Alice; Valent, Peter; Hofmann, Wolf-Karsten; Cross, Nicholas C.P.; Metzgeroth, Georgia; Reiter, Andreas

2017-01-01

Mast cell leukemia is a rare variant of advanced systemic mastocytosis characterized by at least 20% of mast cells in a bone marrow smear. We evaluated clinical and molecular characteristics of 28 patients with (n=20, 71%) or without an associated hematologic neoplasm. De novo mast cell leukemia was diagnosed in 16 of 28 (57%) patients and secondary mast cell leukemia evolving from other advanced systemic mastocytosis subtypes in 12 of 28 (43%) patients, of which 7 patients progressed while on cytoreductive treatment. Median bone marrow mast cell infiltration was 65% and median serum tryptase was 520 μg/L. C-findings were identified in 26 of 28 (93%) patients. Mutations in KIT (D816V, n=19; D816H/Y, n=5; F522C, n=1) were detected in 25 of 28 (89%) patients and prognostically relevant additional mutations in SRSF2, ASXL1 or RUNX1 (S/A/Rpos) in 13 of 25 (52%) patients. Overall response rate in 18 treatment-naïve patients was 5 of 12 (42%) on midostaurin and 1 of 6 (17%) on cladribine, and after switch 1 of 4 (25%) on midostaurin and 0 of 3 on cladribine, respectively. S/A/Rpos adversely affected response to treatment and progression to secondary mast cell leukemia (n=6) or acute myeloid leukemia (n=3) while on treatment (P<0.05). The median overall survival from mast cell leukemia diagnosis was 17 months as compared to 44 months in a control group of 124 patients with advanced systemic mastocytosis but without mast cell leukemia (P=0.03). In multivariate analyses, S/A/Rpos remained the only independent poor prognostic variable predicting overall survival (P=0.007). In conclusion, the molecular signature should be determined in all patients with mast cell leukemia because of its significant clinical and prognostic relevance. PMID:28255023

Role of mast cells in bronchial contraction in nonallergic obstructive lung pathology

PubMed Central

Kuzubova, Nataliya A.; Lebedeva, Elena S.; Titova, Olga N.; Fedin, Anatoliy N.; Dvorakovskaya, Ivetta V.

2017-01-01

Abstract The role of mast cells in contractile bronchial smooth muscle activity has been evaluated in a model of chronic obstructive pulmonary disease induced in rats that were intermittently exposed to nitrogen dioxide (NO2) for 60 days. Starting from the 31st day, one group of rats inhaled sodium cromoglycate before exposure to NO2 to stabilize mast cell membranes. The second group (control) was not treated. Isometric smooth muscle contraction was analysed in isolated bronchial samples in response to nerve and smooth muscle stimulation. Histological analysis revealed large numbers of mast cells in lung tissue of COPD model rats. The inhibition of mast cell degranulation by sodium cromoglycate prevented the development of nerve-stimulated bronchial smooth muscle hyperactivity in COPD model rats. Histamine or adenosine-induced hyperactivity on nerve stimulation was also inhibited by sodium cromoglycate in bronchial smooth muscle in both control and COPD model rats. This suggests that the mechanism of contractile activity enhancement of bronchial wall smooth muscle cells may be mediated through the activation of resident mast cells transmembrane adenosine receptors resulting in their partial degranulation, with the released histamine acting upon histamine H1-receptors which trigger reflex pathways via intramural ganglion neurons. PMID:28867718

KSC-01pp1274

NASA Image and Video Library

2001-07-11

KENNEDY SPACE CENTER, Fla. -- Workers clean the mobile launcher platform on which sits Space Shuttle Atlantis. They are standing in front of one of two tail service masts on either side of the Shuttle, in front of each wing. The masts support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft T-0 umbilicals. Launch on mission STS-104 is scheduled for 5:04 a.m. July 12. The launch is the 10th assembly flight to the International Space Station. Along with a crew of five, Atlantis will carry the joint airlock module as primary payload

Airway responsiveness to mannitol in asthma is associated with chymase-positive mast cells and eosinophilic airway inflammation.

PubMed

Sverrild, A; Bergqvist, A; Baines, K J; Porsbjerg, C; Andersson, C K; Thomsen, S F; Hoffmann, H J; Gibson, P; Erjefält, J S; Backer, V

2016-02-01

Airway hyperresponsiveness (AHR) to inhaled mannitol is associated with indirect markers of mast cell activation and eosinophilic airway inflammation. It is unknown how AHR to mannitol relates to mast cell phenotype, mast cell function and measures of eosinophilic inflammation in airway tissue. We compared the number and phenotype of mast cells, mRNA expression of mast cell-associated genes and number of eosinophils in airway tissue of subjects with asthma and healthy controls in relation to AHR to mannitol. Airway hyperresponsiveness to inhaled mannitol was measured in 23 non-smoking, corticosteroid-free asthmatic individuals and 10 healthy controls. Mast cells and eosinophils were identified in mucosal biopsies from all participants. Mast cells were divided into phenotypes based on the presence of chymase. mRNA expression of mast cell-associated genes was measured by real-time PCR. The proportion of submucosal MCTC was higher in asthmatic individuals with AHR to mannitol compared with asthmatic individuals without AHR (median: 40.3% vs. 18.7%, P = 0.03). Increased submucosal MCTC numbers were associated with increased levels of mRNA for thymic stromal lymphopoietin (TSLP) and CPA3 in asthmatics. Reactivity to mannitol correlated significantly with eosinophils in submucosa (r(s): 0.56, P = 0.01). Airway hyperresponsiveness to inhaled mannitol is associated with an altered submucosal mast cell profile in asthmatic individuals. This mast cell profile is associated with increased levels of TSLP and CPA3. The degree of AHR to mannitol is correlated with the degree of eosinophilic inflammation in the airway submucosa. © 2015 John Wiley & Sons Ltd.

Effect of Omegaven on mast cell concentration in diabetic wound healing.

PubMed

Babaei, Saeid; Ansarihadipour, Hadi; Nakhaei, Mahmoodreza; Darabi, Mohammadreza; Bayat, Parvindokht; Sakhaei, Mohammadhassan; Baazm, Maryam; Mohammadhoseiny, Atefe

2017-05-01

Diabetic wound healing is a complicated process. In all over the world 15% of 200 million diabetic people suffer from diabetic foot problems. Mast cells are known to participate in three phases of wound healing: the inflammatory reaction, angiogenesis and extracellular-matrix reabsorption. The inflammatory reaction is mediated by released histamine and arachidonic acid metabolites. Omega-3 fatty acids alter proinflammatory cytokine production during wound healing which affects the presence of inflammatory cells in wound area as well, but how this events specifically influences the presence of mast cells in wound healing is not clearly understood. This study is conducted to determine the effect of Omegaven, eicosapentaenoic (EPA) and docosahexaenoic (DHA) on pattern of presence of mast cells in diabetic wound area. Diabetic male wistar rats were euthanized at 1, 3, 5, 7 and 15 days after the excision was made. To estimate the number of mast cells histological sections were provided from wound area and stained with toluidine blue. In this relation wound area (8400 microscopic field, 45.69 mm 2 ) were examined by stereological methods by light microscope. We found that comparing experimental and control group, omega-3 fatty acids significantly decreased wound area in day 7 and also the number of grade three mast cells in day 3 and 5. We also found that wound strength has significantly increased in experimental group at day 15. Copyright © 2016. Published by Elsevier Ltd.

A compact, smart Langmuir Probe control module for MAST-Upgrade

NASA Astrophysics Data System (ADS)

Lovell, J.; Stephen, R.; Bray, S.; Naylor, G.; Elmore, S.; Willett, H.; Peterka, M.; Dimitrova, M.; Havranek, A.; Hron, M.; Sharples, R.

2017-11-01

A new control module for the MAST-Upgrade Langmuir Probe system has been developed. It is based on a Xilinx Zynq FPGA, which allows for excellent configurability and ease of retrieving data. The module is capable of arbitrary bias voltage waveform generation, and digitises current and voltage readings from 16 probes. The probes are biased and measured one at a time in a time multiplexed fashion, with the multiplexing sequence completely configurable. In addition, simultaneous digitisation of the floating potential of all unbiased probes is possible. A suite of these modules, each coupled with a high voltage amplifier, enables biasing and digitisation of 640 Langmuir Probes in the MAST-Upgrade Super-X divertor. The system has been successfully tested on the York Linear Plasma Device and on the COMPASS tokamak. It will be installed on MAST-Upgrade ready for operations in 2018.

Communication between mast cells and rat submucosal neurons.

PubMed

Bell, Anna; Althaus, Mike; Diener, Martin

2015-08-01

Histamine is a mast cell mediator released e.g. during food allergy. The aim of the project was to identify the effect of histamine on rat submucosal neurons and the mechanisms involved. Cultured submucosal neurons from rat colon express H1, H2 and H3 receptors as shown by immunocytochemical staining confirmed by reverse transcriptase polymerase chain reaction (RT-PCR) with messenger RNA (mRNA) isolated from submucosal homogenates as starting material. Histamine evoked a biphasic rise of the cytosolic Ca(2+) concentration in cultured submucosal neurons, consisting in a release of intracellularly stored Ca(2+) followed by an influx from the extracellular space. Although agonists of all three receptor subtypes evoked an increase in the cytosolic Ca(2+) concentration, experiments with antagonists revealed that mainly H1 (and to a lesser degree H2) receptors mediate the response to histamine. In coculture experiments with RBL-2H3 cells, a mast cell equivalent, compound 48/80, evoked an increase in the cytosolic Ca(2+) concentration of neighbouring neurons. Like the response to native histamine, the neuronal response to the mast cell degranulator was strongly inhibited by the H1 receptor antagonist pyrilamine and reduced by the H2 receptor antagonist cimetidine. In rats sensitized against ovalbumin, exposure to the antigen induced a rise in short-circuit current (I sc) across colonic mucosa-submucosa preparations without a significant increase in paracellular fluorescein fluxes. Pyrilamine strongly inhibited the increase in I sc, a weaker inhibition was observed after blockade of protease receptors or 5-lipoxygenase. Consequently, H1 receptors on submucosal neurons seem to play a pivotal role in the communication between mast cells and the enteric nervous system.

Evidence for mast cells contributing to neuromuscular pathology in an inherited model of ALS

PubMed Central

Trias, Emiliano; Ibarburu, Sofía; Barreto-Núñez, Romina; Varela, Valentina; Moura, Ivan C.; Hermine, Olivier

2017-01-01

Evidence indicates that neuroinflammation contributes to motor neuron degeneration in amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease leading to progressive muscular paralysis. However, it remains elusive whether inflammatory cells can interact with degenerating distal motor axons, influencing the progressive denervation of neuromuscular junctions (NMJs). By analyzing the muscle extensor digitorum longus (EDL) following paralysis onset in the SOD1G93A rat model, we have observed a massive infiltration and degranulation of mast cells, starting after paralysis onset and correlating with progressive NMJ denervation. Remarkably, mast cells accumulated around degenerating motor axons and NMJs, and were also associated with macrophages. Mast cell accumulation and degranulation in paralytic EDL muscle was prevented by systemic treatment over 15 days with masitinib, a tyrosine kinase inhibitor currently in clinical trials for ALS exhibiting pharmacological activity affecting mast cells and microglia. Masitinib-induced mast cell reduction resulted in a 35% decrease in NMJ denervation and reduced motor deficits as compared with vehicle-treated rats. Masitinib also normalized macrophage infiltration, as well as regressive changes in Schwann cells and capillary networks observed in advanced paralysis. These findings provide evidence for mast cell contribution to distal axonopathy and paralysis progression in ALS, a mechanism that can be therapeutically targeted by masitinib. PMID:29046475

Exploring a regulatory role for mast cells: 'MCregs'?

PubMed

Frossi, Barbara; Gri, Giorgia; Tripodo, Claudio; Pucillo, Carlo

2010-03-01

Regulatory cells can mould the fate of the immune response by direct suppression of specific subsets of effector cells, or by redirecting effectors against invading pathogens and infected or neoplastic cells. These functions have been classically, although not exclusively, ascribed to different subsets of T cells. Recently, mast cells have been shown to regulate physiological and pathological immune responses, and thus to act at the interface between innate and adaptive immunity assuming different functions and behaviors at discrete stages of the immune response. Here, we focus on these poorly defined, and sometimes apparently conflicting, functions of mast cells. Copyright 2010 Elsevier Ltd. All rights reserved.

Mast cells exert pro-inflammatory effects of relevance to the pathophyisology of tendinopathy.

PubMed

Behzad, Hayedeh; Sharma, Aishwariya; Mousavizadeh, Rouhollah; Lu, Alex; Scott, Alex

2013-01-01

We have previously found an increased mast cell density in tendon biopsies from patients with patellar tendinopathy compared to controls. This study examined the influence of mast cells on basic tenocyte functions, including production of the inflammatory mediator prostaglandin E2 (PGE2), extracellular matrix remodeling and matrix metalloproteinase (MMP) gene transcription, and collagen synthesis. Primary human tenocytes were stimulated with an established human mast cell line (HMC-1). Extracellular matrix remodeling was studied by culturing tenocytes in a three-dimensional collagen lattice. Survival/proliferation was assessed with the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium salt (MTS) assay. Levels of mRNA for COX-2, COL1A1, MMP1, and MMP7 were determined by quantitative real-time polymerase chain reaction (qPCR). Cox-2 protein level was assessed by Western blot analysis and type I procollagen was detected by immunofluorescent staining. PGE2 levels were determined using an enzyme-linked immunosorbent assay (ELISA). Mast cells stimulated tenocytes to produce increased levels of COX-2 and the pro-inflammatory mediator PGE2, which in turn decreased COL1A1 mRNA expression. Additionally, mast cells reduced the type I procollagen protein levels produced by tenocytes. Transforming growth factor beta 1 (TGF-β1) was responsible for the induction of Cox-2 and PGE2 by tenocytes. Mast cells increased MMP1 and MMP7 transcription and increased the contraction of a three-dimensional collagen lattice by tenocytes, a phenomenon which was blocked by a pan-MMP inhibitor (Batimastat). Our data demonstrate that mast cell-derived PGE2 reduces collagen synthesis and enhances expression and activities of MMPs in human tenocytes.

Substance P induces adverse myocardial remodelling via a mechanism involving cardiac mast cells

PubMed Central

Meléndez, Giselle C.; Li, Jianping; Law, Brittany A.; Janicki, Joseph S.; Supowit, Scott C.; Levick, Scott P.

2011-01-01

Aims Substance P and neurokinin A (NKA) are sensory nerve neuropeptides encoded by the TAC1 gene. Substance P is a mast cell secretagogue and mast cells are known to play a role in adverse myocardial remodelling. Therefore, we wondered whether substance P and/or NKA modulates myocardial remodelling via a mast cell-mediated mechanism. Methods and results Volume overload was induced by aortocaval fistula in TAC1−/− mice and their respective wild types. Left ventricular internal diameter of wild-type (WT) fistulas increased by 31.9%; this was prevented in TAC1−/− mice (4.2%). Matrix metalloproteinase (MMP) activity was significantly increased in WT fistula mice and was prevented in TAC1−/− mice. Myocardial collagen volume fraction was decreased in WT fistula mice; this collagen degradation was not observed in the TAC1−/− group. There were no significant differences between any groups in tumour necrosis factor (TNF)-α or cell death. Cardiac mast cells were isolated from rat hearts and stimulated with substance P or NKA. We found that these cells degranulated only to substance P, via the neurokinin-1 receptor. To determine the effect of substance P on mast cells in vivo, volume overload was created in Sprague-Dawley rats treated with the NK-1 receptor antagonist L732138 (5 mg/kg/day) for a period of 3 days. L732138 prevented: (i) increases in cardiac mast cell density; (ii) increased myocardial TNF-α; and (iii) collagen degradation. Conclusions Our studies suggest that substance P may be important in mediating adverse myocardial remodelling secondary to volume overload by activating cardiac mast cells, leading to increased TNF-α and MMP activation with subsequent degradation of the extracellular matrix. PMID:21908647

Mast cells and their mediators in cutaneous wound healing--active participants or innocent bystanders?

PubMed

Artuc, M; Hermes, B; Steckelings, U M; Grützkau, A; Henz, B M

1999-02-01

Mast cells are traditionally viewed as effector cells of immediate type hypersensitivity reactions. There is, however, a growing body of evidence that the cells might play an important role in the maintenance of tissue homeostasis and repair. We here present our own data and those from the literature elucidating the possible role of mast cells during wound healing. Studies on the fate of mast cells in scars of varying ages suggest that these cells degranulate during wounding, with a marked decrease of chymase-positive cells, although the total number of cells does not decrease, based on SCF-receptor staining. Mast cells contain a plethora of preformed mediators like heparin, histamine, tryptase, chymase, VEGF and TNF-alpha which, on release during the initial stages of wound healing, affect bleeding and subsequent coagulation and acute inflammation. Various additional vasoactive and chemotactic, rapidly generated mediators (C3a, C5a, LTB4, LTC4, PAF) will contribute to these processes, whereas mast cell-derived proinflammatory and growth promoting peptide mediators (VEGF, FGF-2, PDGF, TGF-beta, NGF, IL-4, IL-8) contribute to neoangiogenesis, fibrinogenesis or re-epithelization during the repair process. The increasing number of tryptase-positive mast cells in older scars suggest that these cells continue to be exposed to specific chemotactic, growth- and differentiation-promoting factors throughout the process of tissue remodelling. All these data indicate that mast cells contribute in a major way to wound healing. their role as potential initiators of or as contributors to this process, compared to other cell types, will however have to be further elucidated.

Aging-associated shifts in functional status of mast cells located by adult and aged mesenteric lymphatic vessels

PubMed Central

Chatterjee, Victor

2012-01-01

We had previously proposed the presence of permanent stimulatory influences in the tissue microenvironment surrounding the aged mesenteric lymphatic vessels (MLV), which influence aged lymphatic function. In this study, we performed immunohistochemical labeling of proteins known to be present in mast cells (mast cell tryptase, c-kit, prostaglandin D2 synthase, histidine decarboxylase, histamine, transmembrane protein 16A, and TNF-α) with double verification of mast cells in the same segment of rat mesentery containing MLV by labeling with Alexa Fluor 488-conjugated avidin followed by toluidine blue staining. Additionally, we evaluated the aging-associated changes in the number of mast cells located by MLV and in their functional status by inducing mast cell activation by various activators (substance P; anti-rat DNP Immunoglobulin E; peptidoglycan from Staphyloccus aureus and compound 48/80) in the presence of ruthenium red followed by subsequent staining by toluidine blue. We found that there was a 27% aging-associated increase in the total number of mast cells, with an ∼400% increase in the number of activated mast cells in aged mesenteric tissue in resting conditions with diminished ability of mast cells to be newly activated in the presence of inflammatory or chemical stimuli. We conclude that higher degree of preactivation of mast cells in aged mesenteric tissue is important for development of aging-associated impairment of function of mesenteric lymphatic vessels. The limited number of intact aged mast cells located close to the mesenteric lymphatic compartments to react to the presence of acute stimuli may be considered contributory to the aging-associated deteriorations in immune response. PMID:22796537

KSC01PD1761

NASA Image and Video Library

2001-12-03

KENNEDY SPACE CENTER, Fla. -- The Rotating Service Structure on Launch Pad 39B rolls away from Space Shuttle Endeavour atop the Mobile Launcher Platform. The Space Shuttle comprises the orbiter and an external tank flanked by twin solid rocket boosters. Above the external tank is the Gaseous Oxygen Vent Arm that vents gaseous oxygen vapors away from the Shuttle. The vent hood assembly at the end is often referred to as the "beanie cap." On either side of the orbiter's tail and main engines are two tail masts that support the fluid, gas and electrical requirements of the orbiter's liquid oxygen and liquid hydrogen aft T-0 umbilicals. . Each tail mast is 31 feet (9.4 meters) high, 15 feet (4.6 meters) long and 9 feet (3.1 meters) wide. Endeavour is scheduled to launch on mission STS-108 Dec. 4 at 5:45 p.m. EST. On this 12th flight to the International Space Station, known as a Utilization Flight, Endeavour will carry a crew of four plus the Expedition 4 crew, who will replace Expedition 3 aboard the ISS. The payload includes the Multi-Purpose Logistics Module Raffaello, filled with supplies, equipment and experiments

KENNEDY SPACE CENTER, FLA. - A closeup of crawler-transportation (CT) number 2 shows the new muffler system on the vehicle. The CT also recently underwent modifications to the cab. The CT is transporting a Mobile Launch Platform (MLP). The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

NASA Image and Video Library

2003-08-18

KENNEDY SPACE CENTER, FLA. - A closeup of crawler-transportation (CT) number 2 shows the new muffler system on the vehicle. The CT also recently underwent modifications to the cab. The CT is transporting a Mobile Launch Platform (MLP). The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

KENNEDY SPACE CENTER, FLA. - Crawler-transporter (CT) number 2, moves away from the Vehicle Assembly Building with a Mobile Launcher Platform (MLP) on top on a test run to the launch pad. The CT recently underwent modifications to the cab. The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

NASA Image and Video Library

2003-08-18

KENNEDY SPACE CENTER, FLA. - Crawler-transporter (CT) number 2, moves away from the Vehicle Assembly Building with a Mobile Launcher Platform (MLP) on top on a test run to the launch pad. The CT recently underwent modifications to the cab. The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

KENNEDY SPACE CENTER, FLA. - Crawler-transporter (CT) number 2 nears the launch pad with a Mobile Launcher Platform (MLP) on top. After recent modifications to the cab and muffler system, the CT was taken on a test run. The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

NASA Image and Video Library

2003-08-19

KENNEDY SPACE CENTER, FLA. - Crawler-transporter (CT) number 2 nears the launch pad with a Mobile Launcher Platform (MLP) on top. After recent modifications to the cab and muffler system, the CT was taken on a test run. The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

KENNEDY SPACE CENTER, FLA. - A closeup of crawler-transporter (CT) number 2 shows the cab, at left, that recently underwent modifications. The CT is transporting a Mobile Launch Platform (MLP) on a test run to the pad. The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

NASA Image and Video Library

2003-08-18

KENNEDY SPACE CENTER, FLA. - A closeup of crawler-transporter (CT) number 2 shows the cab, at left, that recently underwent modifications. The CT is transporting a Mobile Launch Platform (MLP) on a test run to the pad. The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

KENNEDY SPACE CENTER, FLA. - A closeup of crawler-transporter (CT) number 2 shows the cab (left, above the tracks) that recently underwent modifications. The CT is transporting a Mobile Launch Platform (MLP) on a test run to the pad. The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

NASA Image and Video Library

2003-08-18

KENNEDY SPACE CENTER, FLA. - A closeup of crawler-transporter (CT) number 2 shows the cab (left, above the tracks) that recently underwent modifications. The CT is transporting a Mobile Launch Platform (MLP) on a test run to the pad. The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

Evaluation of mast cells, eosinophils, blood capillaries in oral lichen planus and oral lichenoid mucositis.

PubMed

Reddy, D Santhosh; Sivapathasundharam, B; Saraswathi, T R; SriRam, G

2012-01-01

Mast cells are granule containing secretory cells present in oral mucosal and connective tissue environment. Oral lichen planus and oral lichenoid lesions are commonly occurring oral diseases and have some similarity clinically and histologically. Both are characterized by an extensive sub epithelial infiltrate of T cells, together with mast cells, eosinophils and blood capillaries. In this study mast cell and eosinophil densities along with number of blood capillaries were studied to find out if they could aid in histopathological distinction between oral lichen planus and lichenoid mucositis. To enumerate mast cells and compare the status of Mast Cells (Intact or Degranulated) in Lichen planus, Lichenoid mucositis and normal buccal mucosa in tissue sections stained with Toluidine Blue, and also to enumerate Eosinophils and blood capillaries in tissue sections stained with H and E. The study group included 30 cases each of oral lichen planus and oral lichenoid mucositis. 10 cases of clinically normal oral buccal mucosa formed the control group. All the sections were stained with Toluidine blue and H and E separately. Histopathological analysis was done using binocular light microscope equipped with square ocular grid to standardize the field of evaluation. The result of the study showed. · Significant increase in number of mast cells in oral lichen planus and oral lichenoid mucositis compared to normal buccal mucosa. · Significant increase of intact mast cells suepithelially within the inflammatory cell infiltrate in oral lichen planus compared to oral lichenoid mucositis. · Significant increase of degranulated mast cells in oral lichenoid mucositis to oral lichen planus, and increase in number of eosinophil densities in oral lichenoid mucositis compared to oral lichen planus. · Significant increase in number of capillaries in oral lichenoid mucositis compared to oral lichen planus. The findings of increased number of intact mast cells sub epithelially in oral

Tail gut cyst.

PubMed

Rao, G Mallikarjuna; Haricharan, P; Ramanujacharyulu, S; Reddy, K Lakshmi

2002-01-01

The tail gut is a blind extension of the hindgut into the tail fold just distal to the cloacal membrane. Remnants of this structure may form tail gut cyst. We report a 14-year-old girl with tail gut cyst that presented as acute abdomen. The patient recovered after cyst excision.

Critical role of tissue mast cells in controlling long-term glucose sensor function in vivo.

PubMed

Klueh, Ulrike; Kaur, Manjot; Qiao, Yi; Kreutzer, Donald L

2010-06-01

Little is known about the specific cells, mediators and mechanisms involved in the loss of glucose sensor function (GSF) in vivo. Since mast cells (MC) are known to be key effector cells in inflammation and wound healing, we hypothesized that MC and their products are major contributors to the skin inflammation and wound healing that controls GSF at sites of sensor implantation. To test this hypothesis we utilized a murine model of continuous glucose monitoring (CGM) in vivo in both normal C57BL/6 mice (mast cell sufficient), as well as mast cell deficient B6.Cg-Kit(W-sh)/HNihrJaeBsmJ (Sash) mice over a 28 day CGM period. As expected, both strains of mice displayed excellent CGM for the first 7 days post sensor implantation (PSI). CGM in the mast cell sufficient C57BL/6 mice was erratic over the remaining 21 days PSI. CGM in the mast cell deficient Sash mice displayed excellent sensor function for the entire 28 day of CGM. Histopathologic evaluation of implantation sites demonstrated that tissue reactions in Sash mice were dramatically less compared to the reactions in normal C57BL/6 mice. Additionally, mast cells were also seen to be consistently associated with the margins of sensor tissue reactions in normal C57BL/6 mice. Finally, direct injection of bone marrow derived mast cells at sites of sensor implantation induced an acute and dramatic loss of sensor function in both C57BL/6 and Sash mice. These results demonstrate the key role of mast cells in controlling glucose sensor function in vivo. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Telling tails: selective pressures acting on investment in lizard tails.

PubMed

Fleming, Patricia A; Valentine, Leonie E; Bateman, Philip W

2013-01-01

Caudal autotomy is a common defense mechanism in lizards, where the animal may lose part or all of its tail to escape entrapment. Lizards show an immense variety in the degree of investment in a tail (i.e., length) across species, with tails of some species up to three or four times body length (snout-vent length [SVL]). Additionally, body size and form also vary dramatically, including variation in leg development and robustness and length of the body and tail. Autotomy is therefore likely to have fundamentally different effects on the overall body form and function in different species, which may be reflected directly in the incidence of lost/regenerating tails within populations or, over a longer period, in terms of relative tail length for different species. We recorded data (literature, museum specimens, field data) for relative tail length (n=350 species) and the incidence of lost/regenerating tails (n=246 species). We compared these (taking phylogeny into account) with intrinsic factors that have been proposed to influence selective pressures acting on caudal autotomy, including body form (robustness, body length, leg development, and tail specialization) and ecology (foraging behavior, physical and temporal niches), in an attempt to identify patterns that might reflect adaptive responses to these different factors. More gracile species have relatively longer tails (all 350 spp., P < 0.001; also significant for five of the six families tested separately), as do longer (all species, P < 0.001; Iguanidae, P < 0.05; Lacertidae, P < 0.001; Scindidae, P < 0.001), climbing (all species, P < 0.05), and diurnal (all species, P < 0.01; Pygopodidae, P < 0.01) species; geckos without specialized tails (P < 0.05); or active-foraging skinks (P < 0.05). We also found some relationships with the data for caudal autotomy, with more lost/regenerating tails for nocturnal lizards (all 246 spp., P < 0.01; Scindidae, P < 0.05), larger skinks (P < 0.05), climbing geckos (P < 0

Evidence that Meningeal Mast Cells Can Worsen Stroke Pathology in Mice

PubMed Central

Arac, Ahmet; Grimbaldeston, Michele A.; Nepomuceno, Andrew R.B.; Olayiwola, Oluwatobi; Pereira, Marta P.; Nishiyama, Yasuhiro; Tsykin, Anna; Goodall, Gregory J.; Schlecht, Ulrich; Vogel, Hannes; Tsai, Mindy; Galli, Stephen J.; Bliss, Tonya M.; Steinberg, Gary K.

2015-01-01

Stroke is the leading cause of adult disability and the fourth most common cause of death in the United States. Inflammation is thought to play an important role in stroke pathology, but the factors that promote inflammation in this setting remain to be fully defined. An understudied but important factor is the role of meningeal-located immune cells in modulating brain pathology. Although different immune cells traffic through meningeal vessels en route to the brain, mature mast cells do not circulate but are resident in the meninges. With the use of genetic and cell transfer approaches in mice, we identified evidence that meningeal mast cells can importantly contribute to the key features of stroke pathology, including infiltration of granulocytes and activated macrophages, brain swelling, and infarct size. We also obtained evidence that two mast cell-derived products, interleukin-6 and, to a lesser extent, chemokine (C-C motif) ligand 7, can contribute to stroke pathology. These findings indicate a novel role for mast cells in the meninges, the membranes that envelop the brain, as potential gatekeepers for modulating brain inflammation and pathology after stroke. PMID:25134760

Different Patterns of Mast Cells Distinguish Diffuse from Encapsulated Neurofibromas in Patients with Neurofibromatosis 1

PubMed Central

Tucker, Tracy; Riccardi, Vincent M.; Sutcliffe, Margaret; Vielkind, Juergen; Wechsler, Janine; Wolkenstein, Pierre; Friedman, Jan M.

2011-01-01

Multiple neurofibromas are cardinal features of neurofibromatosis 1 (NF1). Several different types of NF1-associated neurofibromas occur, each distinct in terms of pathological details, clinical presentation, and natural history. Mast cells are present in most neurofibromas and have been shown to be critical to the origin and progression of neurofibromas in both human NF1 and relevant mouse models. In this investigation, the authors determined whether mast cell involvement is the same for all types of NF1-associated neurofibromas. They examined the density and distribution of mast cells within 49 NF1-associated neurofibromas classified histopathologically as diffuse or encapsulated on the basis of the presence or absence of the perineurium or its constituent cells. They made two observations: (1) Diffuse neurofibromas had significantly higher densities of mast cells than did encapsulated neurofibromas, and (2) mast cells were evenly distributed throughout diffuse neurofibromas but were primarily restricted to the periphery of encapsulated neurofibromas. The differences in mast cell density and distribution differentiate the two basic types of NF1-associated neurofibromas, suggesting that the pathogenesis of diffuse and encapsulated neurofibromas may be significantly different. PMID:21525187

The Autoimmune Skin Disease Bullous Pemphigoid: The Role of Mast Cells in Autoantibody-Induced Tissue Injury

PubMed Central

Fang, Hui; Zhang, Yang; Li, Ning; Wang, Gang; Liu, Zhi

2018-01-01

Bullous pemphigoid (BP) is an autoimmune and inflammatory skin disease associated with subepidermal blistering and autoantibodies directed against the hemidesmosomal components BP180 and BP230. Animal models of BP were developed by passively transferring anti-BP180 IgG into mice, which recapitulates the key features of human BP. By using these in vivo model systems, key cellular and molecular events leading to the BP disease phenotype are identified, including binding of pathogenic IgG to its target, complement activation of the classical pathway, mast cell degranulation, and infiltration and activation of neutrophils. Proteinases released by infiltrating neutrophils cleave BP180 and other hemidesmosome-associated proteins, causing DEJ separation. Mast cells and mast cell-derived mediators including inflammatory cytokines and proteases are increased in lesional skin and blister fluids of BP. BP animal model evidence also implicates mast cells in the pathogenesis of BP. However, recent studies questioned the pathogenic role of mast cells in autoimmune diseases such as multiple sclerosis, rheumatoid arthritis, and epidermolysis bullosa acquisita. This review highlights the current knowledge on BP pathophysiology with a focus on a potential role for mast cells in BP and mast cell-related critical issues needing to be addressed in the future. PMID:29545809

Cordia verbenacea and secretion of mast cells in different animal species.

PubMed

de Oliveira, Déborah Mara Costa; Luchini, Ana Carolina; Seito, Leonardo Noboru; Gomes, José Carlos; Crespo-López, María Elena; Di Stasi, Luiz Claudio

2011-05-17

Different plant species from Cordia genera are used in folk medicine as anti-inflammatory medication throughout the tropical and subtropical regions of the world. In Brazil, Cordia verbenacea is a medicinal plant known as "erva-baleeira". The alcoholic extracts, decoctions and infusions with leaves of C. verbenacea are used in Brazilian traditional medicine for treatment of cough, pneumonia, parasitic diseases and, especially, the inflammatory processes. Anti-inflammatory activity was already demonstrated; however, molecular mechanisms of action are not completely understood. Considering the importance of histamine in early events of inflammation and in allergic diseases, we evaluated the effect of ethanol extract of leaves of C. verbenacea on histamine release (in vitro and in vivo studies) from different types of mast cells induced by chemical agents using several species of rodents. The extraction and quantification of histamine were performed by using an automatic fluorometric continuous flow system. The extract of C. verbenacea (30 μg/ml) reduced the in vitro secretion of histamine from rat mast cells induced by ionophore A23187, concanavalin A and compound 48/80, respectively, to 22.1 ± 2.2%, 24.3 ± 2.5% and 21.4 ± 2.1%. At the same concentration, the extract also inhibited the secretion of histamine from mast cells of guinea pig induced by ionophore A23187 to 33.3 ± 2.2%, and mast cells of hamster induced by ionophore A23187 and concanavalin A to 15.8 ± 2.5% and 10.8 ± 2.6%, respectively. The oral treatment with the extract (300 mg/kg) also inhibited the secretion of histamine induced by A23187 about to 36.3 ± 3.2% in rats. C. verbenacea inhibits the in vitro secretion of histamine from mast cells of different animal species, as well as the secretion of mast cells from animals treated with the extract, which gives not only the proven anti-inflammatory effect of the plant, but also anti-allergic effect, opening new possibilities for future anti

Current options in the treatment of mast cell mediator-related symptoms in mastocytosis.

PubMed

Escribano, Luis; Akin, Cem; Castells, Mariana; Schwartz, Lawrence B

2006-01-01

Patients with mastocytosis have symptoms related to the tissue response to the release of mediators from mast cells (MC), local mast cell burden or associated non-mast cell hematological disorders. MC contain an array of biologically active mediators in their granules, which are preformed and stored. MC are also able to produce newly generated membrane-derived lipid mediators and are a source of multifunctional cytokines. Mediator-related symptoms can include pruritus, flushing, syncope, gastric distress, nausea and vomiting, diarrhea, bone pain and neuropsychiatric disturbances; these symptoms are variably controlled by adequate medications. Management of patients within all categories of mastocytosis includes: a) a careful counseling of patients (parents in pediatric cases) and care providers, b) avoidance of factors triggering acute mediator release, c) treatment of acute and chronic MC-mediator symptoms and, if indicated, d) an attempt for cytoreduction and treatment of organ infiltration by mast cells.

Non-receptor tyrosine kinases ITK and BTK negatively regulate mast cell pro-inflammatory responses to lipopolysaccharide

PubMed Central

Huang, Weishan; Morales, J. Luis; Gozivoda, Victor P.; August, Avery

2015-01-01

Background Mast cells are indispensible for LPS-induced septic hypothermia, in which TNF-α plays an essential role to initiate septic responses. ITK and BTK regulate mast cell responses to allergen, but their roles in mast cell responses in LPS-induced sepsis are unclear. Objectives We sought to investigate the roles of ITK and BTK in mast cell responses during LPS-induced septic inflammation. Methods Mice (genetically modified or BMMC-reconstituted Sash) were given LPS to induce septic hypothermia, in the presence or absence of indicated inhibitors. Flow cytometry was used to determine LPS-induced cell influx and TNF-α production in peritoneal cells. Microarray was used for genome-wide gene expression analysis on BMMCs. Quantitative PCR and multiplex were used to determine transcribed and secreted pro-inflammatory cytokines. Microscopy and western blotting were used to determine activation of signal transduction pathways. Results The absence of ITK and BTK leads to exacerbation of LPS-induced septic hypothermia and neutrophil influx. Itk−/−Btk−/− mast cells exhibit hyperactive preformed and LPS-induced TNF-α production, and lead to more severe LPS-induced septic hypothermia when reconstituted into mast cell deficient Sash mice. LPS-induced NF-κB, Akt and p38 activation is enhanced in Itk−/−Btk−/− mast cells, and blockage of PI3K, Akt or p38 downstream MNK1 activation significantly suppresses TNF-α hyper-production and attenuates septic hypothermia. Conclusions ITK and BTK regulate thermal homeostasis during septic response through mast cell function in mice. They share regulatory function downstream of TLR4/LPS in mast cells, through regulating the activation of canonical NF-κB, PI3K/Akt and p38 signaling pathways. PMID:26581914

Inhibitory effect of putranjivain A on allergic inflammation through suppression of mast cell activation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Hui-Hun; Park, Seung-Bin; Lee, Soyoung

2014-02-01

A great number of people are suffering from allergic inflammatory disease such as asthma, atopic dermatitis, and sinusitis. Therefore discovery of drugs for the treatment of these diseases is an important subject in human health. Putranjivain A (PJA), member of ellagitannin, is known to possess beneficial effects including anti-cancer and anti-viral activities. The aim of the present study was to elucidate whether PJA modulates the allergic inflammatory reaction and to study its possible mechanisms of action using mast cell-based in vitro and in vivo models. The study was performed in anaphylaxis mouse model and cultured mast cells. PJA inhibited themore » expression of pro-inflammatory cytokines in immunoglobulin E-stimulated mast cells. PJA reduced this expression by inhibiting nuclear factor (NF)-κB and nuclear factor of activated T cell. The oral administration of PJA reduced systemic and cutaneous anaphylaxis, the release of serum histamine, and the expression of the histamine H{sub 1} receptor. In addition, PJA attenuated the activation of mast cells. PJA inhibited the release of histamine from various types of mast cells by the suppression of intracellular calcium. The inhibitory activity of PJA on the allergic reaction was similar to that of disodium cromoglycate, a known anti-allergic drug. These results suggest that PJA can facilitate the prevention or treatment of allergic inflammatory diseases mediated by mast cells. - Highlights: • PJA reduced the degranulation of mast cells. • PJA inhibited the production of inflammatory cytokines. • The effect of PJA on allergic reaction was comparable to the DSCG. • PJA might be a candidate for the treatment of allergic inflammatory diseases.« less

Mast cells and IgE in defense against venoms: Possible "good side" of allergy?

PubMed

Galli, Stephen J; Starkl, Philipp; Marichal, Thomas; Tsai, Mindy

2016-01-01

Physicians think of mast cells and IgE primarily in the context of allergic disorders, including fatal anaphylaxis. This 'bad side' of mast cells and IgE is so well accepted that it can be difficult to think of them in other contexts, particularly those in which they may have beneficial functions. However, there is evidence that mast cells and IgE, as well as basophils (circulating granulocytes whose functions partially overlap with those of mast cells), can contribute to host defense as components of adaptive type 2 immune responses to helminths, ticks and certain other parasites. Accordingly, allergies often are conceptualized as "misdirected" type 2 immune responses, in which IgE antibodies are produced against any of a diverse group of apparently harmless antigens, as well as against components of animal venoms. Indeed, certain unfortunate patients who have become sensitized to venoms develop severe IgE-associated allergic reactions, including fatal anaphylaxis, upon subsequent venom exposure. In this review, we will describe evidence that mast cells can enhance innate resistance to reptile or arthropod venoms during a first exposure to such venoms. We also will discuss findings indicating that, in mice which survive an initial encounter with venom, acquired type 2 immune responses, IgE antibodies, the high affinity IgE receptor (FcɛRI), and mast cells can contribute to acquired resistance to the lethal effects of both honeybee venom and Russell's viper venom. These findings support the hypothesis that mast cells and IgE can help protect the host against venoms and perhaps other noxious substances. Copyright © 2015 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Effectiveness of predator satiation in masting oaks is negatively affected by conspecific density.

PubMed

Bogdziewicz, Michał; Espelta, Josep M; Muñoz, Alberto; Aparicio, Jose M; Bonal, Raul

2018-04-01

Variation in seed availability shapes plant communities, and is strongly affected by seed predation. In some plant species, temporal variation in seed production is especially high and synchronized over large areas, which is called 'mast seeding'. One selective advantage of this phenomenon is predator satiation which posits that masting helps plants escape seed predation through starvation of predators in lean years, and satiation in mast years. However, even though seed predation can be predicted to have a strong spatial component and depend on plant densities, whether the effectiveness of predator satiation in masting plants changes according to the Janzen-Connell effect has been barely investigated. We studied, over an 8-year period, the seed production, the spatiotemporal patters of weevil seed predation, and the abundance of adult weevils in a holm oak (Quercus ilex) population that consists of trees interspersed at patches covering a continuum of conspecific density. Isolated oaks effectively satiate predators, but this is trumped by increasing conspecific plant density. Lack of predator satiation in trees growing in dense patches was caused by re-distribution of insects among plants that likely attenuated them against food shortage in lean years, and changed the type of weevil functional response from type II in isolated trees to type III in trees growing in dense patches. This study provides the first empirical evaluation of the notion that masting and predator satiation should be more important in populations that start to dominate their communities, and is consistent with the observation that masting is less frequent and less intense in diverse forests.

Neurotensin increases mortality and mast cells reduce neurotensin levels in a mouse model of sepsis.

PubMed

Piliponsky, Adrian M; Chen, Ching-Cheng; Nishimura, Toshihiko; Metz, Martin; Rios, Eon J; Dobner, Paul R; Wada, Etsuko; Wada, Keiji; Zacharias, Sherma; Mohanasundaram, Uma M; Faix, James D; Abrink, Magnus; Pejler, Gunnar; Pearl, Ronald G; Tsai, Mindy; Galli, Stephen J

2008-04-01

Sepsis is a complex, incompletely understood and often fatal disorder, typically accompanied by hypotension, that is considered to represent a dysregulated host response to infection. Neurotensin (NT) is a 13-amino-acid peptide that, among its multiple effects, induces hypotension. We find that intraperitoneal and plasma concentrations of NT are increased in mice after severe cecal ligation and puncture (CLP), a model of sepsis, and that mice treated with a pharmacological antagonist of NT, or NT-deficient mice, show reduced mortality during severe CLP. In mice, mast cells can degrade NT and reduce NT-induced hypotension and CLP-associated mortality, and optimal expression of these effects requires mast cell expression of neurotensin receptor 1 and neurolysin. These findings show that NT contributes to sepsis-related mortality in mice during severe CLP and that mast cells can lower NT concentrations, and suggest that mast cell-dependent reduction in NT levels contributes to the ability of mast cells to enhance survival after CLP.

Proanthocyanidin-rich Pinus radiata bark extract inhibits mast cell-mediated anaphylaxis-like reactions.

PubMed

Choi, Yun Ho; Song, Chang Ho; Mun, Sung Phil

2018-02-01

Mast cells play a critical role in the effector phase of immediate hypersensitivity and allergic reactions. Pinus radiata bark extract exerts multiple biological effects and exhibits immunomodulatory and antioxidant properties. However, its role in mast cell-mediated anaphylactic reactions has not been thoroughly investigated. In this study, we examined the effects of proanthocyanidin-rich water extract (PAWE) isolated from P. radiata bark on compound 48/80-induced or antidinitrophenyl (DNP) immunoglobulin E (IgE)-mediated anaphylaxis-like reactions in vivo. In addition, we evaluated the mechanism underlying the inhibitory effect of PAWE on mast cell activation, with a specific focus on histamine release, using rat peritoneal mast cells. PAWE attenuated compound 48/80-induced or anti-DNP IgE-mediated passive cutaneous anaphylaxis-like reactions in mice, and it inhibited histamine release triggered by compound 48/80, ionophore A23187, or anti-DNP IgE in rat peritoneal mast cells in vitro. Moreover, PAWE suppressed compound 48/80-elicited calcium uptake in a concentration-dependent manner and promoted a transient increase in intracellular cyclic adenosine-3',5'-monophosphate levels. Together, these results suggest that proanthocyanidin-rich P. radiata bark extract effectively inhibits anaphylaxis-like reactions. Copyright © 2017 John Wiley & Sons, Ltd.

30 CFR 57.7051 - Loose objects on the mast or drill platform.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Loose objects on the mast or drill platform. 57... Drilling and Rotary Jet Piercing Drilling-Surface and Underground § 57.7051 Loose objects on the mast or drill platform. To prevent injury to personnel, tools and other objects shall not be left loose on the...

30 CFR 57.7051 - Loose objects on the mast or drill platform.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Loose objects on the mast or drill platform. 57... Drilling and Rotary Jet Piercing Drilling-Surface and Underground § 57.7051 Loose objects on the mast or drill platform. To prevent injury to personnel, tools and other objects shall not be left loose on the...

30 CFR 57.7051 - Loose objects on the mast or drill platform.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Loose objects on the mast or drill platform. 57... Drilling and Rotary Jet Piercing Drilling-Surface and Underground § 57.7051 Loose objects on the mast or drill platform. To prevent injury to personnel, tools and other objects shall not be left loose on the...

Cardiac mast cell-derived renin promotes local angiotensin formation, norepinephrine release, and arrhythmias in ischemia/reperfusion.

PubMed

Mackins, Christina J; Kano, Seiichiro; Seyedi, Nahid; Schäfer, Ulrich; Reid, Alicia C; Machida, Takuji; Silver, Randi B; Levi, Roberto

2006-04-01

Having identified renin in cardiac mast cells, we assessed whether its release leads to cardiac dysfunction. In Langendorff-perfused guinea pig hearts, mast cell degranulation with compound 48/80 released Ang I-forming activity. This activity was blocked by the selective renin inhibitor BILA2157, indicating that renin was responsible for Ang I formation. Local generation of cardiac Ang II from mast cell-derived renin also elicited norepinephrine release from isolated sympathetic nerve terminals. This action was mediated by Ang II-type 1 (AT1) receptors. In 2 models of ischemia/reperfusion using Langendorff-perfused guinea pig and mouse hearts, a significant coronary spillover of renin and norepinephrine was observed. In both models, this was accompanied by ventricular fibrillation. Mast cell stabilization with cromolyn or lodoxamide markedly reduced active renin overflow and attenuated both norepinephrine release and arrhythmias. Similar cardioprotection was observed in guinea pig hearts treated with BILA2157 or the AT1 receptor antagonist EXP3174. Renin overflow and arrhythmias in ischemia/reperfusion were much less prominent in hearts of mast cell-deficient mice than in control hearts. Thus, mast cell-derived renin is pivotal for activating a cardiac renin-angiotensin system leading to excessive norepinephrine release in ischemia/reperfusion. Mast cell-derived renin may be a useful therapeutic target for hyperadrenergic dysfunctions, such as arrhythmias, sudden cardiac death, myocardial ischemia, and congestive heart failure.

Flavonoids inhibit histamine release and expression of proinflammatory cytokines in mast cells.

PubMed

Park, Hyo-Hyun; Lee, Soyoung; Son, Hee-Young; Park, Seung-Bin; Kim, Mi-Sun; Choi, Eun-Ju; Singh, Thoudam S K; Ha, Jeoung-Hee; Lee, Maan-Gee; Kim, Jung-Eun; Hyun, Myung Chul; Kwon, Taeg Kyu; Kim, Yeo Hyang; Kim, Sang-Hyun

2008-10-01

Mast cells participate in allergy and inflammation by secreting inflammatory mediators such as histamine and proinflammatory cytokines. Flavonoids are naturally occurring molecules with antioxidant, cytoprotective, and antiinflammatory actions. However, effect of flavonoids on the release of histamine and proinflammatory mediator, and their comparative mechanism of action in mast cells were not well defined. Here, we compared the effect of six flavonoids (astragalin, fisetin, kaempferol, myricetin, quercetin, and rutin) on the mast cell-mediated allergic inflammation. Fisetin, kaempferol, myricetin, quercetin, and rutin inhibited IgE or phorbol-12-myristate 13-acetate and calcium ionophore A23187 (PMACI)-mediated histamine release in RBL-2H3 cells. These five flavonoids also inhibited elevation of intracellular calcium. Gene expressions and secretion of proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, IL-6, and IL-8 were assessed in PMACI-stimulated human mast cells (HMC-1). Fisetin, quercetin, and rutin decreased gene expression and production of all the proinflammatory cytokines after PMACI stimulation. Myricetin attenuated TNF-alpha and IL-6 but not IL-1beta and IL-8. Fisetin, myricetin, and rutin suppressed activation of NF-kappaB indicated by inhibition of nuclear translocation of NF-kappaB, NF-kappaB/DNA binding, and NF-kappaB-dependent gene reporter assay. The pharmacological actions of these flavonoids suggest their potential activity for treatment of allergic inflammatory diseases through the down-regulation of mast cell activation.

Review of black-tailed prairie dog reintroduction strategies and site selection: Arizona reintroduction

Treesearch

Sarah L. Hale; John L. Koprowski; Holly Hicks

2013-01-01

The black-tailed prairie dog (Cynomys ludovicianus) was once widely distributed throughout the western United States; however, anthropogenic influences have reduced the species’ numbers to 2 percent of historical populations. Black-tailed prairie dogs are described as a keystone species in the grassland ecosystem, and provide many unique services, including burrows for...

FcepsilonRI-alpha siRNA inhibits the antigen-induced activation of mast cells.

PubMed

Safaralizadeh, Reza; Soheili, Zahra-Soheila; Deezagi, Abdolkhaleg; Pourpak, Zahra; Samiei, Shahram; Moin, Mostafa

2009-12-01

FcepsilonRI, The high affinity receptor for IgE plays a critical role in triggering the allergic reactions. It is responsible for inducing mast cell degranulation and deliberation of allergy mediators when it is aggregated by allergen and IgE complexes. FcepsilonRI on the mast cells consists of three subunits; alpha chain directly binds IgE, beta chain and dimmer of gamma chains together mediate intracellular signaling. Cross-linking of IgE-bound FcepsilonRI on the surface of mast cells and basophils by the multivalent antigen induces release of chemical mediators. The present in vitro study was designed to investigate the effect of synthetic FcepsilonRI-alpha siRNA on the antigen-induced activation of MC/9 cells. MC/9 cells which are murine mast cells were transfected by FcepsilonRI-alpha siRNA and negative control siRNA. After 6 h, anti-DNP (Dinitrophenyl) IgE was used for the cells sensitization. Then the cells were challenged with Dinitrophenyl-Human Serum Albumin (DNP-HSA) for mast cell degranulation induction before collection of supernatants. The amount of mRNA and protein expression was measured by Real Time PCR and western blot analysis, respectively. Determination of the expression rate of FcepsilonRI-alpha on cell surface was achieved by flow cytometry. ELISA and spectrophotometry methods were used subsequently for measuring the effects of FcepsilonRI-alpha siRNA on antigen-induced histamine and beta-hexosaminidase release. FcepsilonRI-alpha siRNA treated cells showed significant decrease in FcepsilonRI-alpha mRNA and protein expression in comparison to control cells. FcepsilonRI-mediated mast cell release of beta-hexosaminidase and histamine were also inhibited. In this study it was shown that FcepsilonRI-alpha siRNA could suppress FcepsilonRI-alpha expression and inhibited degranulation and histamine release in antigen-stimulated MC/9 cells. In conclusion, knock-down of FcepsilonRI-alpha by siRNA could be a promising method for inhibition of the mast

Nonclinical evaluation of the potential for mast cell activation by an erythropoietin analog

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weaver, James L., E-mail: James.Weaver@fda.hhs.gov; Boyne, Michael, E-mail: mboyne@biotechlogic.com; Pang, Eric, E-mail: Eric.Pang@fda.hhs.gov

The erythropoietin analog peginesatide was withdrawn from marketing due to unexpected severe anaphylactic reactions associated with administration of the multi-use formulation. The adverse events occurred rapidly following the first ever administration of the drug with most affected patients becoming symptomatic in less than 30 min. This is most consistent with an anaphylactoid reaction due to direct activation of mast cells. Laboratory evaluation was undertaken using rat peritoneal mast cells as the model system. Initial studies showed that high concentrations of the formulated drug as well as formulated vehicle alone could cause mast cell degranulation as measured by histamine release. Themore » purified active drug was not able to cause histamine release whereas the vehicle filtrate and lab created drug vehicle were equally potent at causing histamine release. Individual formulations of vehicle leaving one component out showed that histamine release was due to phenol. Dose response studies with phenol showed a very sharp dose response curve that was similar in three buffer systems. Cellular analysis by flow cytometry showed that the histamine release was not due to cell death, and that changes in light scatter parameters consistent with degranulation were rapidly observed. Limited testing with primary human mast cells showed a similar dose response of histamine release with exposure to phenol. To provide in vivo confirmation, rats were injected with vehicle formulated with various concentrations of phenol via a jugular vein cannula. Significant release of histamine was detected in blood samples taken 2 min after dosing at the highest concentrations tested. - Highlights: • Peginesatide caused severe anaphylactoid reactions in 0.2% of patients. • Both formulated drug and vehicle cause degranulation of rat mast cells. • Phenol was identified as the vehicle component causing degranulation. • Human mast cells show similar dose response to phenol as rat mast

Inhibition of human mast cell growth and differentiation by interferon gamma-1b.

PubMed

Kirshenbaum, A S; Worobec, A S; Davis, T A; Goff, J P; Semere, T; Metcalfe, D D

1998-03-01

In an effort to identify cytokines that inhibit human mast cell growth, we cultured HMC-1 cells and recombinant human stem cell factor (rhSCF)-dependent human bone marrow-derived mast cells (HBMCs) in the presence of interferon gamma (IFNgamma)-1b and interferon alpha (IFNalpha)-2b. HMC-1 cell numbers decreased in the presence of 1000 U/mL IFNgamma-1b but were unaffected by 1000 U/mL of IFNalpha-2b. HBMCs were then cultured for 0 to 7 days with 100 ng/mL rhSCF and 10 ng/mL recombinant human IL-3 (rhIL-3), followed by culture in rhSCF and administration of either 1000 U/mL IFNalpha-2b or 1000 U/mL IFNgamma-1b. HBMCs appearing in cultures with rhSCF alone or in combination with IFNalpha-2b were virtually identical in number through 8 weeks of culture. In cultures supplemented with IFNgamma-1b, HBMCs significantly decreased in number and incidence of granular metachromasia by 4 to 5 weeks (p<0.001). Similar results were obtained when human marrow was cultured from day 0 with rhSCF and IFNgamma-1b. Mature rhSCF-dependent HBMCs were also cultured at 5 weeks with rhSCF alone or in combination with IFNgamma-1b. Compared with cells cultured in rhSCF, mature 5-week HBMC cultures treated with rhSCF plus IFNgamma-1b revealed a decrease in mast cells, and those mast cells that remained had fewer toluidine blue- and tryptase-positive granules after 5 to 8 weeks. FACS analysis of rhSCF plus IFNgamma-1b-treated mature HBMCs revealed increased c-kit and Fc(epsilon)RI expression. Mast cell releasibility was not increased. IFNgamma-lb was thus able to suppress mast cell growth from CD34+ cells, suggesting that this agent should be considered as a candidate cytokine for the treatment of disorders of mast cell proliferation.

Induction of mast cell proliferation, maturation, and heparin synthesis by the rat c-kit ligand, stem cell factor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsai, M.; Takeishi, Takashi; Geissler, E.N.

1991-07-15

The authors investigated the effects of a newly recognized multifunctional growth factor, the c-kit ligand stem cell factor (SCF), on mouse mast cell proliferation and phenotype. Recombinant rat SCF{sup 164} (rrSCF{sup 164}) induced the development of large numbers of dermal mast cells in normal mice in vivo. Many of these mast cells had features of connective tissue-type mast cells (CTMC), in that they were reactive both with the heparin-binding fluorescent dye berberine sulfate and with safranin. In vitro, rrSCF{sup 164} induced the proliferation of cloned interleukin 3 (IL-3)-dependent mouse mast cells and primary populations of IL-3-dependent, bone marrow-derived cultured mastmore » cells (BMCMC), which represent immature mast cells, and purified peritoneal mast cells, which represent a type of mature CTMC> BMCMC maintained in rrSCF{sup 164} not only proliferated but also matured. These findings identify SCF as a single cytokine that can induce immature, IL-3-dependent mast cells to mature and to acquire multiple characteristics of CTMC. These findings also directly demonstrate that SCF can regulate the development of a cellular lineage expressing c-kit through effects on both proliferation and maturation.« less

Bait stations, hard mast, and black bear population growth in Great Smoky Mountains National Park

USGS Publications Warehouse

Clark, Joseph D.; van Manen, Frank T.; Pelton, Michael R.

2005-01-01

Bait-station surveys are used by wildlife managers as an index to American black bear (Ursus americanus) population abundance, but the relationship is not well established. Hard mast surveys are similarly used to assess annual black bear food availability which may affect mortality and natality rates. We used data collected in Great Smoky Mountains National Park (GSMNP) from 1989 to 2003 to determine whether changes in the bait-station index (ΔBSI) were associated with estimated rates of bear population growth (λ) and whether hard mast production was related to bear visitation to baits. We also evaluated whether hard mast production from previous years was related to λ. Estimates of λ were based on analysis of capture-recapture data with the Pradel temporal symmetry estimator. Using the Akaike's Information Criterion (AIC), our analysis revealed no direct relationship between ΔBSI and λ. A simulation analysis indicated that our data were adequate to detect a relationship had one existed. Model fit was marginally improved when we added total oak mast production of the previous year as an interaction term suggesting that the BSI was confounded with environmental variables. Consequently the utility of the bait-station survey as a population monitoring technique is questionable at the spatial and temporal scales we studied. Mast survey data, however, were valuable covariates of λ. Population growth for a given year was negatively related to oak mast production 4 and 5 years prior. That finding supported our hypothesis that mast failures can trigger reproductive synchrony, which may not be evident from the trapped sample until years later.

Initial response of individual soft mast-producing plants to different forest regeneration methods in the Ouachita Mountains

Treesearch

Roger W. Perry; Ronald E. Thill; Philip A. Tappe; David G. Peitz

2004-01-01

Abstract - Recent policy changes have eliminated clearcutting as the primary pine regeneration method on Federal lands in the Southern United States. However, the effects of alternative natural regeneration methods on soft mast production are unknown. We compared plant coverage and mast production of 37 soft mast-producing plants among four...

Controlling Mast Cell Activation and Homeostasis: Work Influenced by Bill Paul That Continues Today.

PubMed

Caslin, Heather L; Kiwanuka, Kasalina N; Haque, Tamara T; Taruselli, Marcela T; MacKnight, H Patrick; Paranjape, Anuya; Ryan, John J

2018-01-01

Mast cells are tissue resident, innate immune cells with heterogenous phenotypes tuned by cytokines and other microenvironmental stimuli. Playing a protective role in parasitic, bacterial, and viral infections, mast cells are also known for their role in the pathogenesis of allergy, asthma, and autoimmune diseases. Here, we review factors controlling mast cell activation, with a focus on receptor signaling and potential therapies for allergic disease. Specifically, we will discuss our work with FcεRI and FγR signaling, IL-4, IL-10, and TGF-β1 treatment, and Stat5. We conclude with potential therapeutics for allergic disease. Much of these efforts have been influenced by the work of Bill Paul. With many mechanistic targets for mast cell activation and different classes of therapeutics being studied, there is reason to be hopeful for continued clinical progress in this area.

Differences in irradiation susceptibility and turnover between mucosal and connective tissue-type mast cells of mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fukuzumi, T.; Waki, N.; Kanakura, Y.

Although precursors of mast cells are derived from the bone marrow, phenotypes of mast cells are influenced by the tissues in which final differentiation occurs. Connective tissue-type mast cells (CTMC) and mucosal mast cells (MMC) are different in morphological, biochemical, immunological, and functional criteria. The purpose of the present study was to obtain information about the differentiation process of MMC. First, we compared changes in irradiation susceptibility in mice during the differentiation process of CTMC and MMC. The decrease in irradiation susceptibility was remarkable in the CTMC differentiation process, but it was moderate in that of MMC. Some morphologically identifiablemore » CTMC in the peritoneal cavity had proliferative potential and were highly radioresistant, whereas such a radioresistant population of MMC was not detectable in the gastric mucosa. Second, we estimated the turnover of CTMC and MMC by determining the proportion of mast cells that were labeled with continuously administered bromodeoxyuridine. The turnover of MMC was significantly faster than that of CTMC. The absence of the radioresistant mast cell population in the gastric mucosa appeared to be related to the short life span of MMC.« less

STS-104 Atlantis on pad after RSS rollback

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- This view from above Space Shuttle Atlantis reduces the workers below to appearing like ants. Seen below the Shuttle is the opening over the exhaust hole containing flame detectors. On either side of the Atlantis, in front of the wings, are two tail service masts. The masts support the fluid, gas and electrical requirements of the orbiters liquid oxygen and liquid hydrogen aft T-0 umbilicals. Launch on mission STS-104 is scheduled for 5:04 a.m. July 12. The launch is the 10th assembly flight to the International Space Station. Along with a crew of five, Atlantis will carry the joint airlock module as primary payload.

Autonomous Performance Monitoring System: Monitoring and Self-Tuning (MAST)

NASA Technical Reports Server (NTRS)

Peterson, Chariya; Ziyad, Nigel A.

2000-01-01

Maintaining the long-term performance of software onboard a spacecraft can be a major factor in the cost of operations. In particular, the task of controlling and maintaining a future mission of distributed spacecraft will undoubtedly pose a great challenge, since the complexity of multiple spacecraft flying in formation grows rapidly as the number of spacecraft in the formation increases. Eventually, new approaches will be required in developing viable control systems that can handle the complexity of the data and that are flexible, reliable and efficient. In this paper we propose a methodology that aims to maintain the accuracy of flight software, while reducing the computational complexity of software tuning tasks. The proposed Monitoring and Self-Tuning (MAST) method consists of two parts: a flight software monitoring algorithm and a tuning algorithm. The dependency on the software being monitored is mostly contained in the monitoring process, while the tuning process is a generic algorithm independent of the detailed knowledge on the software. This architecture will enable MAST to be applicable to different onboard software controlling various dynamics of the spacecraft, such as attitude self-calibration, and formation control. An advantage of MAST over conventional techniques such as filter or batch least square is that the tuning algorithm uses machine learning approach to handle uncertainty in the problem domain, resulting in reducing over all computational complexity. The underlying concept of this technique is a reinforcement learning scheme based on cumulative probability generated by the historical performance of the system. The success of MAST will depend heavily on the reinforcement scheme used in the tuning algorithm, which guarantees the tuning solutions exist.

The Relationship Between Basal Area and Hard Mast Production in the Ouachita Mountains

Treesearch

Roger W. Perry; Ronald E. Thill; Philip A. Tappe; David G. Peitz

2004-01-01

Abstract - Because the relationship between stand density and hard mast production is not clear, we investigated the effects of varying total overstory basal area (BA) on acorn and hickory nut production in the Ouachita Mountains. We used Whitehead visual surveys to estimate mast production in oaks (Quercus spp.) and hickories (...

REAR PROFILE OF TAIL FROM SECOND LEVEL OF TAIL DOCK ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

REAR PROFILE OF TAIL FROM SECOND LEVEL OF TAIL DOCK STAND, SHOWING AIRCRAFT NUMBER (319), HORIZONTAL STABILIZER, TAIL CONE AND COOLING CTS FOR THE AUXILIARY POWER UNIT (APU), MECHANIC PAUL RIDEOUT IS LOWERING THE BALANCE PANELS ON THE STABILIZERS FOR LUBRICATION AND INSPECTION. - Greater Buffalo International Airport, Maintenance Hangar, Buffalo, Erie County, NY

Neurotensin increases mortality and mast cells reduce neurotensin levels in a mouse model of sepsis

PubMed Central

Piliponsky, Adrian M.; Chen, Ching-Cheng; Nishimura, Toshihiko; Metz, Martin; Rios, Eon J.; Dobner, Paul R.; Wada, Etsuko; Wada, Keiji; Zacharias, Sherma; Mohanasundaram, Uma; Faix, James D.; Abrink, Magnus; Pejler, Gunnar; Pearl, Ronald; Tsai, Mindy; Galli, Stephen J.

2010-01-01

Sepsis is a complex, incompletely understood and often fatal disorder,1 typically accompanied by hypotension,2 that is considered to represent a dysregulated host response to infection.3,4,5 Neurotensin (NT) is a 13-amino-acid peptide that, among its multiple effects, induces hypotension.6 We find that intraperitoneal and plasma concentrations of NT are increased in mice after severe caecal ligation and puncture (CLP), a model of sepsis, and that mice treated with a pharmacological antagonist of NT, or NT-deficient mice, exhibit reduced mortality during severe CLP. In mice, mast cells can degrade NT and reduce NT-induced hypotension and CLP-associated mortality, and optimal expression of these effects requires mast cell expression of neurotensin receptor 1 and neurolysin. These findings show that NT contributes to sepsis-related mortality in mice during severe CLP and that mast cells can lower NT concentrations, and suggest that mast cell-dependent reduction in NT levels contributes to the ability of mast cells to enhance survival after CLP. PMID:18376408

Correlated seed failure as an environmental veto to synchronize reproduction of masting plants.

PubMed

Bogdziewicz, Michał; Steele, Michael A; Marino, Shealyn; Crone, Elizabeth E

2018-07-01

Variable, synchronized seed production, called masting, is a widespread reproductive strategy in plants. Resource dynamics, pollination success, and, as described here, environmental veto are possible proximate mechanisms driving masting. We explored the environmental veto hypothesis, which assumes that reproductive synchrony is driven by external factors preventing reproduction in some years, by extending the resource budget model of masting with correlated reproductive failure. We ran this model across its parameter space to explore how key parameters interact to drive seeding dynamics. Next, we parameterized the model based on 16 yr of seed production data for populations of red (Quercus rubra) and white (Quercus alba) oaks. We used these empirical models to simulate seeding dynamics, and compared simulated time series with patterns observed in the field. Simulations showed that resource dynamics and reproduction failure can produce masting even in the absence of pollen coupling. In concordance with this, in both oaks, among-year variation in resource gain and correlated reproductive failure were necessary and sufficient to reproduce masting, whereas pollen coupling, although present, was not necessary. Reproductive failure caused by environmental veto may drive large-scale synchronization without density-dependent pollen limitation. Reproduction-inhibiting weather events are prevalent in ecosystems, making described mechanisms likely to operate in many systems. © 2018 The Authors New Phytologist © 2018 New Phytologist Trust.

Immunohistochemical expression of mast cell tryptase in giant cell fibroma and inflammatory fibrous hyperplasia of the oral mucosa.

PubMed

Santos, Pedro Paulo de Andrade; Nonaka, Cassiano Francisco Weege; Pinto, Leão Pereira; de Souza, Lélia Batista

2011-03-01

This study analysed the immunohistochemical expression of mast cell tryptase in giant cell fibromas (GCFs). In addition, the possible interaction of mast cells with stellate giant cells, as well as their role in fibrosis and tumour progression, was investigated. For this purpose, the results were compared with cases of inflammatory fibrous hyperplasia (IFH) and normal oral mucosa. Thirty cases of GCF, 30 cases of IFH and 10 normal mucosa specimens used as control were selected. Immunoreactivity of mast cells to the anti-tryptase antibody was analysed quantitatively in the lining epithelium and in connective tissue. In the epithelial component (p=0.250) and connective tissue (p=0.001), the largest mean number of mast cells was observed in IFHs and the smallest mean number in GCFs. In connective tissue, the mean percentage of degranulated mast cells was higher in GCFs than in IFHs and normal mucosa specimens (p<0.001). Analysis of the percentage of degranulated mast cells in areas of fibrosis and at the periphery of blood vessels also showed a larger mean number in GCFs compared to IFHs and normal mucosa specimens (p<0.001). The percent interaction between mast cells and stellate giant cells in GCFs was 59.62%. In conclusion, although mast cells were less numerous in GCFs, the cells exhibited a significant interaction with stellate giant cells present in these tumours. In addition, the results suggest the involvement of mast cells in the induction of fibrosis and modulation of endothelial cell function in GCFs. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

Mast cells contribute to the mucosal adjuvant effect of CTA1-DD after IgG-complex formation.

PubMed

Fang, Yu; Larsson, Lisa; Mattsson, Johan; Lycke, Nils; Xiang, Zou

2010-09-01

Mast cell activation is one of the most dramatic immune-mediated responses the body can encounter. In the worst scenario (i.e., anaphylaxis), this response is fatal. However, the importance of mast cells as initiators and effectors of both innate and adaptive immunity in healthy individuals has recently been appreciated. It was reported that mast cell activation can be used as an adjuvant to promote Ag-specific humoral immune responses upon vaccination. In this study, we have used a clinically relevant mucosal adjuvant, cholera toxin A1 subunit (CTA1)-DD, which is a fusion protein composed of CTA1, the ADP-ribosylating part of cholera toxin, and DD, two Ig-binding domains derived from Staphylococcus aureus protein A. CTA1-DD in combination with polyclonal IgG induced degranulation and production of TNF-alpha from mouse mast cells. Furthermore, CTA1-DD and polyclonal IgG complex induced mast cell degranulation in mouse skin tissue and nasal mucosa. We also found that intranasal immunization with hapten (4-hydroxy-3-nitrophenyl) acetyl (NP) coupled to chicken gammaglobulin admixed with CTA1-DD complexed with polyclonal IgG greatly enhanced serum IgG anti-NP Ab responses and stimulated higher numbers of NP-specific plasma cells in the bone marrow as compared with that observed in mice immunized with NP-chicken gammaglobulin with CTA1-DD alone. This CTA1-DD/IgG complex-mediated enhancement was mast cell dependent because it was absent in mast cell-deficient Kit(W-sh/W-sh) mice. In conclusion, our data suggest that a clinically relevant adjuvant, CTA1-DD, exerts additional augmenting effects through activation of mucosal mast cells, clearly demonstrating that mast cells could be further exploited for improving the efficacy of mucosal vaccines.

Mast cell, the peculiar member of the immune system: A homeostatic aspect.

PubMed

Csaba, György

2015-09-01

The mast cell is a member of the immune system having a basic role in allergic (anaphylactic) reactions. However, it contains, synthesizes, stores and secretes lots of substances, which initiates other reactions or participates in them. These are in connection with the deterioration of tissue correlation, as malignant tumors, angiogenesis, wound healing, pregnancy and different pathological conditions. In addition - as other members of the immune system - mast cells can synthesize, store and secrete hormones characteristic to the endocrine glands and can transport them to the site of requirement (packed transport), or produce and employ them locally. The effect of mast cells is controversial and frequently dual, stimulatory or inhibitory to the same organ or process. This is likely due to the heterogeneity of the mast cells, in morphology and cell content alike and dependent on the actual condition of the targeted tissue. The cells are transported in an unmatured form by the blood circulation and are exposed to microenvironmental effects, which influence their maturation. Their enrichment around tumors suggested using them as targets for tumor therapy more than fifty years ago (by the author), however, this idea lives its renaissance now. The review discusses the facts and ideas critically.

A Role for Human Skin Mast Cells in Dengue Virus Infection and Systemic Spread.

PubMed

Troupin, Andrea; Shirley, Devon; Londono-Renteria, Berlin; Watson, Alan M; McHale, Cody; Hall, Alex; Hartstone-Rose, Adam; Klimstra, William B; Gomez, Gregorio; Colpitts, Tonya M

2016-12-01

Dengue virus (DENV) is a mosquito-borne flavivirus that causes serious global human disease and mortality. Skin immune cells are an important component of initial DENV infection and systemic spread. Here, we show that mast cells are a target of DENV in human skin and that DENV infection of skin mast cells induces degranulation and alters cytokine and growth factor expression profiles. Importantly, to our knowledge, we also demonstrate for the first time that DENV localizes within secretory granules in infected skin mast cells. In addition, DENV within extracellular granules was infectious in vitro and in vivo, trafficking through lymph to draining lymph nodes in mice. We demonstrate an important role for human skin mast cells in DENV infection and identify a novel mechanism for systemic spread of DENV infection from the initial peripheral mosquito injection site. Copyright © 2016 by The American Association of Immunologists, Inc.

Hematopoietic Kit Deficiency, rather than Lack of Mast Cells, Protects Mice from Obesity and Insulin Resistance.

PubMed

Gutierrez, Dario A; Muralidhar, Sathya; Feyerabend, Thorsten B; Herzig, Stephan; Rodewald, Hans-Reimer

2015-05-05

Obesity, insulin resistance, and related pathologies are associated with immune-mediated chronic inflammation. Kit mutant mice are protected from diet-induced obesity and associated co-morbidities, and this phenotype has previously been attributed to their lack of mast cells. We performed a comprehensive metabolic analysis of Kit-dependent Kit(W/Wv) and Kit-independent Cpa3(Cre/+) mast-cell-deficient mouse strains, employing diet-induced or genetic (Lep(Ob/Ob) background) models of obesity. Our results show that mast cell deficiency, in the absence of Kit mutations, plays no role in the regulation of weight gain or insulin resistance. Moreover, we provide evidence that the metabolic phenotype observed in Kit mutant mice, while independent of mast cells, is immune regulated. Our data underscore the value of definitive mast cell deficiency models to conclusively test the involvement of this enigmatic cell in immune-mediated pathologies and identify Kit as a key hematopoietic factor in the pathogenesis of metabolic syndrome. Copyright © 2015 Elsevier Inc. All rights reserved.

The pivotal role of fibrocytes and mast cells in mediating fibrotic reactions to biomaterials

PubMed Central

Thevenot, Paul T.; Baker, David W.; Weng, Hong; Sun, Man-Wu; Tang, Liping

2011-01-01

Almost all biomaterial implants are surrounded by a fibrotic capsule, although the mechanism of biomaterial-mediated fibrotic reactions is mostly unclear. To search for the types of cells responsible for triggering the tissue responses, we used poly-L glycolic acid polymers capable of releasing various reagents. We first identified that CD45+ /Collagen 1+ fibrocytes are recruited and resided within the fibrotic capsule at the implant interface. Interestingly, we found that the recruitment of fibrocytes and the extent of fibrotic tissue formation (collagen type I production) were substantially enhanced and reduced by the localized release of compound 48/80 and cromolyn, respectively. Since it is well established that compound 48/80 and cromolyn alter mast cell reactions, we hypothesized that mast cells are responsible for triggering fibrocyte recruitment and subsequent fibrotic capsule formation surrounding biomaterial implants. To directly test this hypothesis, similar studies were carried out using mast cell deficient mice, WBB6F1/J-KitW/KitW-v/, and their congenic controls. Indeed, mast cell deficient mice prompted substantially less fibrocyte and myofibroblast responses in comparison to C-57 wild type mice controls. Most interestingly, subcutaneous mast cell reconstitution of WBB6F1/J-KitW/KitW-v/J mice almost completely restored the fibrocyte response in comparison to the C-57 wild type response. These results indicate that the initial biomaterial interaction resulting in the stimulation of mast cells and degranulation byproducts not only stimulates the inflammatory cascade but significantly alters the downstream fibrocyte response and degree of fibrosis. PMID:21864899

(E,Z)-3-(3',5'-Dimethoxy-4'-hydroxy-benzylidene)-2-indolinone blocks mast cell degranulation.

PubMed

Kiefer, S; Mertz, A C; Koryakina, A; Hamburger, M; Küenzi, P

2010-05-12

(E,Z)-3-(3',5'-Dimethoxy-4'-hydroxy-benzylidene)-2-indolinone (indolinone) is an alkaloid that has been identified as a pharmacologically active compound in extracts of the traditional anti-inflammatory herb Isatis tinctoria. Indolinone has been shown to inhibit compound 48/80-induced mast cell degranulation in vitro. Application of indolinone to bone marrow derived mast cells showed that it was uniformly distributed in the cytoplasm and that cellular uptake was terminated within minutes. Pre-treatment of IgE-sensitized mast cells with 100nM indolinone rendered them insensitive against FcvarepsilonRI-receptor dependent degranulation. However, upstream signalling induced by antigen such as activation of PI3-K and MAPK remained unaffected. We conclude that indolinone blocks mast cell degranulation at the level of granule exocitosis with an IC(50) of 54nm.

Top of Mars Rover Curiosity Remote Sensing Mast

NASA Image and Video Library

2011-04-06

The remote sensing mast on NASA Mars rover Curiosity holds two science instruments for studying the rover surroundings and two stereo navigation cameras for use in driving the rover and planning rover activities.

Identification of mast cells in buffy coat preparations from dogs with inflammatory skin diseases.

PubMed

Cayatte, S M; McManus, P M; Miller, W H; Scott, D W

1995-02-01

In 100 dogs with 4 inflammatory dermatologic diseases, buffy coat preparations from EDTA-treated blood samples were examined cytologically. Fifty-four dogs had atopy, 26 had flea-bite hypersensitivity, 17 had sarcoptic mange, and 3 had food allergy. Twenty-eight dogs had 2 or more concurrent skin diseases; most of these had secondary pyoderma. Dogs did not have mast cell tumors. Thirteen samples contained 1 or more mast cells/4 slides reviewed. This study revealed that dogs with inflammatory skin diseases can have a few to many mast cells evident on cytologic examination of buffy coat preparations.

SAO/NASA ADS at SAO: ADS Browse Service

Science.gov Websites

Sign on [SAO/NASA ADS] ADS Browse Service ADS Home | HELP | Sitemap ADS Services Search Browse myADS Mirrors Feedback FAQ What's new Site Map Help Other NASA Centers CXC HEASARC IRSA MAST NED NSSDC -Smithsonian Center for Astrophysics [ Smithsonian logo ] The NASA Astrophysics Data System provides different

Upregulated expression of substance P (SP) and NK1R in eczema and SP-induced mast cell accumulation.

PubMed

Zhan, Mengmeng; Zheng, Wenjiao; Jiang, Qijun; Zhao, Zuotao; Wang, Zhiyun; Wang, Junling; Zhang, Huiyun; He, Shaoheng

2017-08-01

Substance P (SP) was reported to be associated with eczema and acts as a potent skin mast cell secretagogue. However, little is known of its expression in inflammatory cells in eczema and its ability in induction of mast cell accumulation. In the present study, we investigated expression of SP and neurokinin-1 receptor (NK1R) on peripheral blood leukocytes and mast cells from patients with eczema and influence of SP on mast cell accumulation by using flow cytometry analysis, trans-epithelial cell migration assay and mouse peritoneal model. The results showed that plasma SP and IL-17A levels in eczema patients were higher than that in healthy control subject. The percentages of SP+ and NK1R+ expression populations of monocytes, helper T cells, natural killer T cells and basophils in peripheral blood of eczema patients were markedly elevated. It was observed that not only absolute number of mast cells but also SP+ and NK1R+ mast cells are enhanced in the lesion skin of eczema. SP showed a potent chemoattractant action on mast cells as assessed by a mouse peritoneal model and a trans-endothelium cell migration assay. SP-induced mast cell accumulation appears a CD18/CD11a complex, L-selectin and ICAM-1-dependent event which can be blocked by a NK-1R antagonist RP67580. In conclusion, elevated expression of SP in patients with eczema and the ability of SP in induction of mast cell accumulation indicate strongly that SP is a potent proinflammatory mediator, which contributes to the pathogenesis of eczema. Inhibitors of SP and blockers of NK1R are likely useful agents for treatment of eczema.

Less contribution of mast cells to the progression of renal fibrosis in Rat kidneys with chronic renal failure.

PubMed

Baba, Asuka; Tachi, Masahiro; Ejima, Yutaka; Endo, Yasuhiro; Toyama, Hiroaki; Saito, Kazutomo; Abe, Nozomu; Yamauchi, Masanori; Miura, Chieko; Kazama, Itsuro

2017-02-01

Chronic renal failure (CRF) is histopathologically characterized by tubulointerstitial fibrosis in addition to glomerulosclerosis. Although mast cells are known to infiltrate into the kidneys with chronic inflammation, we know little about their contribution to the pathogenesis of renal fibrosis associated with CRF. The aim of this study was to reveal the involvement of mast cells in the progression of renal fibrosis in CRF. Using a rat model with CRF resulting from 5/6 nephrectomy, we examined the histopathological features of the kidneys and the infiltration of mast cells into the renal interstitium. By treating the rats with a potent mast cell stabilizer, tranilast, we also examined the involvement of mast cells in the progression of renal fibrosis associated with CRF. The CRF rat kidneys were characterized by the wide staining of collagen III and increased number of myofibroblasts, indicating the progression of renal fibrosis. Compared to T-lymphocytes or macrophages, the number of tryptase-positive mast cells was much smaller within the fibrotic kidneys and they did not proliferate in situ. The mRNA expression of mast cell-derived fibroblast-activating factors was not increased in the renal cortex isolated from CRF rat kidneys. Treatment with tranilast did not suppress the progression of renal fibrosis, nor did it ameliorate the progression of glomerulosclerosis and the interstitial proliferation of inflammatory leukocytes. This study demonstrated for the first time that mast cells are neither increased nor activated in the fibrotic kidneys of CRF rats. Compared to T-lymphocytes or macrophages that proliferate in situ within the fibrotic kidneys, mast cells were less likely to contribute to the progression of renal fibrosis associated with CRF. © 2016 Asian Pacific Society of Nephrology.

Seedling establishment in a masting desert shrub parallels the pattern for forest trees

Treesearch

Susan E. Meyer; Burton K. Pendleton

2015-01-01

The masting phenomenon along with its accompanying suite of seedling adaptive traits has been well studied in forest trees but has rarely been examined in desert shrubs. Blackbrush (Coleogyne ramosissima) is a regionally dominant North American desert shrub whose seeds are produced in mast events and scatter-hoarded by rodents. We followed the fate of seedlings in...

Mast cell activation and neutrophil recruitment promotes early and robust inflammation in the meninges in EAE.

PubMed

Christy, Alison L; Walker, Margaret E; Hessner, Martin J; Brown, Melissa A

2013-05-01

The meninges are often considered inert tissues that house the CSF and provide protection for the brain and spinal cord. Yet emerging data demonstrates that they are also active sites of immune responses. Furthermore, the blood-CSF barrier surrounding meningeal blood vessels, together with the blood-brain barrier (BBB), is postulated to serve as a gateway for the pathological infiltration of immune cells into the CNS in multiple sclerosis (MS). Our previous studies using mast cell-deficient (Kit(W/Wv)) mice demonstrated that mast cells resident in the dura mater and pia mater exacerbate experimental autoimmune encephalomyelitis (EAE), a rodent model of MS, by facilitating CNS inflammatory cell influx. Here we examined the underlying mechanisms that mediate these effects. We demonstrate that there are dramatic alterations in immune associated gene expression in the meninges in pre-clinical disease, including those associated with mast cell and neutrophil function. Meningeal mast cells are activated within 24 h of disease induction, but do not directly compromise CNS vascular integrity. Rather, through production of TNF, mast cells elicit an early influx of neutrophils, cells known to alter vascular permeability, into the meninges. These data add to the growing evidence that inflammation in the meninges precedes CNS immune cell infiltration and establish that mast cells are among the earliest participants in these disease-initiating events. We hypothesize that mast cell-dependent neutrophil recruitment and activation in the meninges promotes early breakdown of the local BBB and CSF-blood barrier allowing initial immune cell access to the CNS. Copyright © 2012 Elsevier Ltd. All rights reserved.

Fatigue failure and cracking in high mast poles.

DOT National Transportation Integrated Search

2012-03-01

This report presents the findings of a comprehensive research project to investigate the fatigue : cracking and failure of galvanized high mast illumination poles (HMIP). Ultrasonic inspection of : poles throughout the state has revealed the presence...

Analysis of MAST-CLA Results as a Diagnostic Tool in Allergic Skin Diseases

PubMed Central

Shin, Jung Won; Jin, Seon-pil; Lee, Jong Hee

2010-01-01

Background Urticaria and atopic dermatitis are representative allergic skin diseases that can be mediated by IgE. Measuring levels of specific IgE can be used to confirm causative agents of these skin diseases. Objective To analyze results from the multiple allergosorbent test chemiluminescent assay (MAST-CLA), which measures specific IgE in the presence of a causative agent/allergen, in IgE-mediated skin diseases. Methods A total of 404 patients with urticaria, atopic dermatitis or pruritus were enrolled in the present study. Positive rates of specific IgE as well as total serum IgE from the MAST-CLA were compared. Results Positive rates of specific IgE were highest in atopic dermatitis patients, followed by urticaria, and then pruritus, with 57.0%, 37.1%, and 20.8%, respectively (p<0.05). House dust mite species were the most common allergens in both atopic dermatitis and urticaria skin diseases. There were no differences in the overall MAST-CLA results between acute and chronic urticaria. The relative positive rate of inhalant allergen was significantly higher in adult than in child atopic dermatitis patients. Conclusion Results from the MAST-CLA showed diversity among the three disease groups, and within each disease group, with different positive rates of specific IgE, a different mean allergen number per patient, and so on. Therefore, we concluded that MAST-CLA could be a useful diagnostic tool for various allergic skin diseases. PMID:20548878

Mast cells are present in the choroid of the normal eye in most vertebrate classes.

PubMed

McMenamin, Paul Gerard; Polla, Emily

2013-07-01

Mast cells are bone marrow-derived tissue-homing leukocytes, which have traditionally been regarded as effector cells in allergic disorders, responses against parasites, and regulation of blood flow, but a broader perspective of their functional heterogeneity, such as immunomodulation, angiogenesis, tissue repair, and remodeling after injury, is now emerging. The persistence of mast cells in connective tissues throughout the evolution of vertebrates is evidence of strong selective pressure suggesting that these cells must have multiple beneficial and important roles in normal homeostasis. While mast cells are present within the uveal tract of eutherian mammals, there is little known about their presence in the choroid of other vertebrate classes. Eye tissues from a range of vertebrate species (fish, amphibian, reptiles, birds, marsupials, monotreme, and eutherian mammals) were investigated. Tissues were fixed in either 2% glutaraldehyde, 2% paraformaldehyde or a mixture of both and processed for resin embedding. Semi-thin sections of the retina and choroid were cut and stained with toluidine blue. Mast cells were identified in the choroid of all classes of vertebrates investigated except sharks. Their morphology, location, and staining characteristics were remarkably similar from teleost fish through to eutherian mammals and bore close morphological resemblance to mammalian connective tissue mast cells. The similar morphology and distribution of mast cells in the choroid of all vertebrate classes studied suggest a basic physiological function that has been retained since the evolution of the vertebrate eye. © 2013 American College of Veterinary Ophthalmologists.

Mast cells and histamine alter intestinal permeability during malaria parasite infection.

PubMed

Potts, Rashaun A; Tiffany, Caitlin M; Pakpour, Nazzy; Lokken, Kristen L; Tiffany, Connor R; Cheung, Kong; Tsolis, Renée M; Luckhart, Shirley

2016-03-01

Co-infections with malaria and non-typhoidal Salmonella serotypes (NTS) can present as life-threatening bacteremia, in contrast to self-resolving NTS diarrhea in healthy individuals. In previous work with our mouse model of malaria/NTS co-infection, we showed increased gut mastocytosis and increased ileal and plasma histamine levels that were temporally associated with increased gut permeability and bacterial translocation. Here, we report that gut mastocytosis and elevated plasma histamine are also associated with malaria in an animal model of falciparum malaria, suggesting a broader host distribution of this biology. In support of mast cell function in this phenotype, malaria/NTS co-infection in mast cell-deficient mice was associated with a reduction in gut permeability and bacteremia. Further, antihistamine treatment reduced bacterial translocation and gut permeability in mice with malaria, suggesting a contribution of mast cell-derived histamine to GI pathology and enhanced risk of bacteremia during malaria/NTS co-infection. Copyright © 2015 Elsevier GmbH. All rights reserved.

Increased mast cell expression of PAR-2 in skin inflammatory diseases and release of IL-8 upon PAR-2 activation.

PubMed

Carvalho, Ricardo Filipe da Silva; Nilsson, Gunnar; Harvima, Ilkka Tapani

2010-02-01

Mast cells are increasingly present in the lesional skin of chronic skin inflammatory diseases including psoriasis and basal cell carcinoma (BCC). It has previously been shown that proteinase-activated receptor (PAR)-2 is expressed by mast cells, and tryptase is a potent activator of this receptor. In this study, skin biopsies from both healthy-looking and lesional skin of patients with psoriasis and superficial spreading BCC were collected and the expression of PAR-2 immunoreactivity in tryptase-positive mast cells was analysed. PAR-2 expression was confirmed in vitro in different mast cell populations. Cord-blood derived mast cells (CBMC) were stimulated with a PAR-2 activating peptide, 2-furoyl-LIGRLO-NH(2). Consequently, IL-8 and histamine production was analysed in the supernatants. We observed a significant increase in the percentage of mast cells expressing PAR-2 in the lesional skin of psoriasis and BCC patients compared with the healthy-looking skin. HMC-1.2, LAD-2 and CBMC mast cells all expressed PAR-2 both intracellularly and on the cell surface. CBMC activation with the PAR-2 activating peptide resulted in an increased secretion of IL-8, but no histamine release was observed. Furthermore, both PAR-2 and IL-8 were co-localized to the same tryptase-positive mast cells in the lesional BCC skin. These results show that mast cells express increased levels of PAR-2 in chronic skin inflammation. Also, mast cells can be activated by a PAR-2 agonist to secrete IL-8, a chemokine which can contribute to the progress of inflammation.

MAST Propellant and Delivery System Design Methods

NASA Technical Reports Server (NTRS)

Nadeem, Uzair; Mc Cleskey, Carey M.

2015-01-01

A Mars Aerospace Taxi (MAST) concept and propellant storage and delivery case study is undergoing investigation by NASA's Element Design and Architectural Impact (EDAI) design and analysis forum. The MAST lander concept envisions landing with its ascent propellant storage tanks empty and supplying these reusable Mars landers with propellant that is generated and transferred while on the Mars surface. The report provides an overview of the data derived from modeling between different methods of propellant line routing (or "lining") and differentiate the resulting design and operations complexity of fluid and gaseous paths based on a given set of fluid sources and destinations. The EDAI team desires a rough-order-magnitude algorithm for estimating the lining characteristics (i.e., the plumbing mass and complexity) associated different numbers of vehicle propellant sources and destinations. This paper explored the feasibility of preparing a mathematically sound algorithm for this purpose, and offers a method for the EDAI team to implement.

Genomic and transcriptomic comparison of allergen and silver nanoparticle-induced mast cell degranulation reveals novel non-immunoglobulin E mediated mechanisms.

PubMed

Johnson, Monica; Alsaleh, Nasser; Mendoza, Ryan P; Persaud, Indushekhar; Bauer, Alison K; Saba, Laura; Brown, Jared M

2018-01-01

Mast cells represent a crucial cell type in host defense; however, maladaptive responses are contributing factors in the pathogenesis of allergic diseases. Previous work in our laboratory has shown that exposure to silver nanoparticles (AgNPs) results in mast cell degranulation via a non-immunoglobulin E (IgE) mechanism. In this study, we utilized a systems biology approach to identify novel genetic factors playing a role in AgNP-induced mast cell degranulation compared to the classical activation by antigen-mediated FcεRI crosslinking. Mast cell degranulation was assessed in bone marrow-derived mast cells isolated from 23 strains of mice following exposure to AgNPs or FcεRI crosslinking with dinitrophenyl (DNP). Utilizing strain-dependent mast cell degranulation, an association mapping study identified 3 chromosomal regions that were significantly associated with mast cell degranulation by AgNP and one non-overlapping region associated with DNP-mediated degranulation. Two of the AgNP-associated regions correspond to genes previously reported to be associated with allergic disorders (Trac2 on chromosome 1 and Traf6 on chromosome 2) and an uncharacterized gene identified on chromosome 1 (Fam126b). In conjunction, RNA-sequencing performed on mast cells from the high and low responder strains revealed 3754 and 34 differentially expressed genes that were unique to DNP and AgNP exposures, respectively. Select candidate genes include Ptger4, a gene encoding a G-protein coupled receptor in addition to a multifunctional adaptor protein, Txnip, that may be driving mast cell degranulation by AgNP. Taken together, we identified novel genes that have not been previously shown to play a role in nanoparticle-mediated mast cell activation. With further functional evaluation in the future, these genes may be potential therapeutic targets in the treatment of non-IgE mediated mast cell-linked disorders.

Mast cell mediators in citric acid-induced airway constriction of guinea pigs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, C.-H.; Lai, Y.-L.

2005-08-15

We demonstrated previously that mast cells play an important role in citric acid (CA)-induced airway constriction. In this study, we further investigated the underlying mediator(s) for this type of airway constriction. At first, to examine effects caused by blocking agents, 67 young Hartley guinea pigs were divided into 7 groups: saline + CA; methysergide (serotonin receptor antagonist) + CA; MK-886 (leukotriene synthesis inhibitor) + CA; mepyramine (histamine H{sub 1} receptor antagonist) + CA; indomethacin (cyclooxygenase inhibitor) + CA; cromolyn sodium (mast cell stabilizer) + CA; and compound 48/80 (mast cell degranulating agent) + CA. Then, we tested whether leukotriene C{submore » 4} (LTC{sub 4}) or histamine enhances CA-induced airway constriction in compound 48/80-pretreated guinea pigs. We measured dynamic respiratory compliance (Crs) and forced expiratory volume in 0.1 s (FEV{sub 0.1}) during either baseline or recovery period. In addition, we detected histamine level, an index of pulmonary mast cell degranulation, in bronchoalveolar lavage (BAL) samples. Citric acid aerosol inhalation caused decreases in Crs and FEV{sub 0.1}, indicating airway constriction in the control group. This airway constriction was significantly attenuated by MK-886, mepyramine, cromolyn sodium, and compound 48/80, but not by either methysergide or indomethacin. Both LTC{sub 4} and histamine infusion significantly increased the magnitude of CA-induced airway constriction in compound 48/80-pretreated guinea pigs. Citric acid inhalation caused significant increase in histamine level in the BAL sample, which was significantly suppressed by compound 48/80. These results suggest that leukotrienes and histamine originating from mast cells play an important role in CA inhalation-induced noncholinergic airway constriction.« less

Porcine mast cells infected with H1N1 influenza virus release histamine and inflammatory cytokines and chemokines.

PubMed

Lee, In Hong; Kim, Hyun Soo; Seo, Sang Heui

2017-04-01

Mast cells reside in many tissues, including the lungs, and might play a role in enhancing influenza virus infections in animals. In this study, we cultured porcine mast cells from porcine bone marrow cells with IL-3 and stem cell factor to study the infectivity and activation of the 2009 pandemic H1N1 influenza virus of swine origin. Porcine mast cells were infected with H1N1 influenza virus, without the subsequent production of infectious viruses but were activated, as indicated by the release of histamines. Inflammatory cytokine- and chemokine-encoding genes, including IL-1α, IL-6, CXCL9, CXCL10, and CXCL11, were upregulated in the infected porcine mast cells. Our results suggest that mast cells could be involved in enhancing influenza-virus-mediated disease in infected animals.

Human Dermal Mast Cells Contain and Release Tumor Necrosis Factor α, which Induces Endothelial Leukocyte Adhesion Molecule 1

NASA Astrophysics Data System (ADS)

Walsh, Laurence J.; Trinchieri, Giorgio; Waldorf, Heidi A.; Whitaker, Diana; Murphy, George F.

1991-05-01

Tumor necrosis factor α (TNF-α) is a proinflammatory cytokine that mediates endothelial leukocyte interactions by inducing expression of adhesion molecules. In this report, we demonstrate that human dermal mast cells contain sizeable stores of immunoreactive and biologically active TNF-α within granules, which can be released rapidly into the extracellular space upon degranulation. Among normal human dermal cells, mast cells are the predominant cell type that expresses both TNF-α protein and TNF-α mRNA. Moreover, induction of endothelial leukocyte adhesion molecule 1 expression is a direct consequence of release of mast cell-derived TNF-α. These findings establish a role for human mast cells as "gatekeepers" of the dermal microvasculature and indicate that mast cell products other than vasoactive amines influence endothelium in a proinflammatory fashion.

Human Mucosal Mast Cells Capture HIV-1 and Mediate Viral trans-Infection of CD4+ T Cells.

PubMed

Jiang, Ai-Ping; Jiang, Jin-Feng; Wei, Ji-Fu; Guo, Ming-Gao; Qin, Yan; Guo, Qian-Qian; Ma, Li; Liu, Bao-Chi; Wang, Xiaolei; Veazey, Ronald S; Ding, Yong-Bing; Wang, Jian-Hua

2015-12-30

The gastrointestinal mucosa is the primary site where human immunodeficiency virus type 1 (HIV-1) invades, amplifies, and becomes persistently established, and cell-to-cell transmission of HIV-1 plays a pivotal role in mucosal viral dissemination. Mast cells are widely distributed in the gastrointestinal tract and are early targets for invasive pathogens, and they have been shown to have increased density in the genital mucosa in HIV-infected women. Intestinal mast cells express numerous pathogen-associated molecular patterns (PAMPs) and have been shown to combat various viral, parasitic, and bacterial infections. However, the role of mast cells in HIV-1 infection is poorly defined. In this study, we investigated their potential contributions to HIV-1 transmission. Mast cells isolated from gut mucosal tissues were found to express a variety of HIV-1 attachment factors (HAFs), such as DC-SIGN, heparan sulfate proteoglycan (HSPG), and α4β7 integrin, which mediate capture of HIV-1 on the cell surface. Intriguingly, following coculture with CD4(+) T cells, mast cell surface-bound viruses were efficiently transferred to target T cells. Prior blocking with anti-HAF antibody or mannan before coculture impaired viral trans-infection. Cell-cell conjunctions formed between mast cells and T cells, to which viral particles were recruited, and these were required for efficient cell-to-cell HIV-1 transmission. Our results reveal a potential function of gut mucosal mast cells in HIV-1 dissemination in tissues. Strategies aimed at preventing viral capture and transfer mediated by mast cells could be beneficial in combating primary HIV-1 infection. In this study, we demonstrate the role of human mast cells isolated from mucosal tissues in mediating HIV-1 trans-infection of CD4(+) T cells. This finding facilitates our understanding of HIV-1 mucosal infection and will benefit the development of strategies to combat primary HIV-1 dissemination. Copyright © 2016, American Society

Clinical Features of Hereditary and Mast Cell-mediated Angioedema Focusing on the Differential Diagnosis in Japanese Patients.

PubMed

Ohsawa, Isao; Honda, Daisuke; Hisada, Atsuko; Inoshita, Hiroyuki; Onda-Tsueshita, Kisara; Mano, Satoshi; Sato, Nobuyuki; Nakamura, Yuya; Shimizu, Tatsuo; Gotoh, Hiromichi; Goto, Yoshikazu; Suzuki, Yusuke; Tomino, Yasuhiko

2018-02-01

Objective The present study was designed to identify the clinical characteristics that permit the differential diagnosis of hereditary angioedema (HAE) and mast cell-mediated angioedema (Mast-AE) during the first consultation. Methods The medical histories and laboratory data of 46 patients with HAE and 41 patients with Mast-AE were compared. Results The average age of onset in the HAE group (19.8±9.0 years) was significantly lower than that in the Mast-AE group (35.2±12.0 years). The incidence of familial angioedema (AE) in the HAE group (73.9%) was significantly higher than that in the Mast-AE group (9.7%). The frequency of history of AE in the extremities, larynx, or gastrointestinal tract was significantly higher in the HAE group. The frequency of AE episodes of the lips and eyelids was significantly lower in the HAE group. The serum C4 concentration and CH50 titer were lower than the normal limit in 91.3% and 45.6% of the patients in the HAE group, respectively; in Mast-AE group the serum C4 concentration and CH50 titer were significantly lower than the normal limit in 4.8% and 0% of the patients, the difference between the two groups was statistically significant. A C1-inhibitor (C1-INH) activity level of <50% was observed in all of the HAE patients, but none of the Mast-AE patients. The mean serum IgE titer in the HAE group (120.8±130.5 IU/mL) was significantly lower than that in the Mast-AE group (262.2±314.9 IU/mL). Conclusion The parameters within the patients' medical histories, such as the age at the onset of AE, a family history of AE, and the locations of past AE episodes are critical for the successful diagnosis of the disease. Measurements of the C4 and C1-INH activity are very useful for differential diagnosis of HAE from Mast-AE.

Cytologic comparison of the percentage of mast cells in lymph node aspirate samples from clinically normal dogs versus dogs with allergic dermatologic disease and dogs with cutaneous mast cell tumors.

PubMed

Mutz, Melanie L; Boudreaux, Bonnie B; Royal, Angela; Merchant, Sandra; Pucheu-Haston, Cherie; Griffith, Emily H; Gieger, Tracy L

2017-08-15

OBJECTIVE To compare percentages of mast cells in lymph node (LN) aspirate samples from clinically normal dogs, dogs with allergic dermatologic disease (ADD), and dogs with cutaneous mast cell tumors (MCTs). DESIGN Prospective cross-sectional study. ANIMALS 20 healthy dogs (group 1), 20 dogs with ADD (group 2), and 20 dogs with an MCT on the head or limbs (group 3). PROCEDURES LN aspirate samples were obtained from easily accessible LNs in group 1, affected skin regions in group 2, and the likely draining LN or LNs of the MCT in group 3; the percentage of mast cells was manually determined for each LN. For group 3, LNs were cytologically categorized with a modified version of a published metastasis categorization scheme. RESULTS Median (range) percentage of mast cells in aspirate samples was 0% (0% to 0.1%) for group 1, 0.05% (0% to 0.55%) for group 2, and 0.4% (0% to 77.4%) for group 3. In group 3, 16 LNs (13 dogs) were palpably normal in size; 6 of these had evidence of possible or certain metastasis. Seven LNs (7 dogs) in group 3 were palpably enlarged, and 5 of these had evidence of certain metastasis. CONCLUSIONS AND CLINICAL RELEVANCE This study provided evidence to support the use of a uniform cytologic grading system to further define nodal metastasis in dogs with MCTs as well as estimates of the percentage of mast cells in LN aspirate samples for healthy dogs and dogs with ADD. Palpably normal LNs in dogs with cutaneous MCT may contain metastasis.

Interaction of primary mast cells with Borrelia burgdorferi (sensu stricto): role in transmission and dissemination in C57BL/6 mice.

PubMed

Bernard, Quentin; Wang, Zhenping; Di Nardo, Anna; Boulanger, Nathalie

2017-06-27

Borrelia burgdorferi (sensu lato), the causative agent of Lyme borreliosis is a bacterium transmitted by hard ticks, Ixodes spp. Bacteria are injected into the host skin during the tick blood meal with tick saliva. There, Borrelia and saliva interact together with skin cells such as keratinocytes, fibroblasts, mast cells and other specific immune cells before disseminating to target organs. To study the role of mast cells in the transmission of Lyme borreliosis, we isolated mouse primary mast cells from bone marrow and incubated them in the presence of Borrelia burgdorferi (sensu stricto) and tick salivary gland extract. We further analyzed their potential role in vivo, in a mouse model of deficient in mast cells (Kit wsh-/- mice). To our knowledge, we report here for the first time the bacteria ability to induce the inflammatory response of mouse primary mast cells. We show that OspC, a major surface lipoprotein involved in the early transmission of Borrelia, induces the degranulation of primary mast cells but has a limited effect on the overall inflammatory response of these cells. In contrast, whole bacteria have an opposite effect. We also show that mast cell activation is significantly inhibited by tick salivary gland extract. Finally, we demonstrate that mast cells are likely not the only host cells involved in the early transmission and dissemination of Borrelia since the use of mast cell deficient Kit wsh-/- mice shows a limited impact on these two processes in the context of this mouse genetic background. The absence of mast cells did not change the replication rate of Borrelia in the skin. However, in the absence of mast cells, Borrelia dissemination to the joints was faster. Mast cells do not control skin bacterial proliferation during primary infection and the establishment of the primary infection, as shown in the C57BL/6 mouse model studied. Nevertheless, the Borrelia induced cytotokine modulation on mast cells might be involved in long term and

A Role for Serglycin Proteoglycan in Mast Cell Apoptosis Induced by a Secretory Granule-mediated Pathway*

PubMed Central

Melo, Fabio Rabelo; Waern, Ida; Rönnberg, Elin; Åbrink, Magnus; Lee, David M.; Schlenner, Susan M.; Feyerabend, Thorsten B.; Rodewald, Hans-Reimer; Turk, Boris; Wernersson, Sara; Pejler, Gunnar

2011-01-01

Mast cell secretory granules (secretory lysosomes) contain large amounts of fully active proteases bound to serglycin proteoglycan. Damage to the granule membrane will thus lead to the release of serglycin and serglycin-bound proteases into the cytosol, which potentially could lead to proteolytic activation of cytosolic pro-apoptotic compounds. We therefore hypothesized that mast cells are susceptible to apoptosis induced by permeabilization of the granule membrane and that this process is serglycin-dependent. Indeed, we show that wild-type mast cells are highly sensitive to apoptosis induced by granule permeabilization, whereas serglycin-deficient cells are largely resistant. The reduced sensitivity of serglycin−/− cells to apoptosis was accompanied by reduced granule damage, reduced release of proteases into the cytosol, and defective caspase-3 activation. Mechanistically, the apoptosis-promoting effect of serglycin involved serglycin-dependent proteases, as indicated by reduced sensitivity to apoptosis and reduced caspase-3 activation in cells lacking individual mast cell-specific proteases. Together, these findings implicate serglycin proteoglycan as a novel player in mast cell apoptosis. PMID:21123167

[Ala12]MCD peptide: a lead peptide to inhibitors of immunoglobulin E binding to mast cell receptors.

PubMed

Buku, A; Condie, B A; Price, J A; Mezei, M

2005-09-01

An effort was made to discover mast cell degranulating (MCD) peptide analogs that bind with high affinity to mast cell receptors without triggering secretion of histamine or other mediators of the allergic reaction initiated by immunoglobulin E (IgE) after mast cell activation. Such compounds could serve as inhibitors of IgE binding to mast cell receptors. An alanine scan of MCD peptide reported previously showed that the analog [Ala12]MCD was 120-fold less potent in histamine-releasing activity and fivefold more potent in binding affinity to mast cell receptors than the parent MCD peptide. Because this analog showed marginal intrinsic activity and good binding affinity it was subsequently tested in the present study as an IgE inhibitor. In contrast to MCD peptide, [Ala12]MCD showed a 50% inhibition of IgE binding to the Fc epsilon RI alpha mast cell receptor by using rat basophilic leukemia (RBL-2H3) mast cells and fluorescence polarization. Furthermore, in a beta-hexosaminidase secretory assay, the peptide also showed a 50% inhibition of the secretion of this enzyme caused by IgE. An attempt was made to relate structural changes and biologic differences between the [Ala12]MCD analog and the parent MCD peptide. The present results show that [Ala12]MCD may provide a base for designing agents to prevent IgE/Fc epsilon RI alpha interactions and, consequently, allergic conditions.

Mast Cell Dependent Vascular Changes Associated with an Acute Response to Cold Immersion in Primary Contact Urticaria

PubMed Central

Meyer, Joseph; Gorbach, Alexander M.; Liu, Wei-Min; Medic, Nevenka; Young, Michael; Nelson, Celeste; Arceo, Sarah; Desai, Avanti; Metcalfe, Dean D.; Komarow, Hirsh D.

2013-01-01

Background While a number of the consequences of mast cell degranulation within tissues have been documented including tissue-specific changes such as bronchospasm and the subsequent cellular infiltrate, there is little known about the immediate effects of mast cell degranulation on the associated vasculature, critical to understanding the evolution of mast cell dependent inflammation. Objective To characterize the microcirculatory events that follow mast cell degranulation. Methodology/Principal Findings Perturbations in dermal blood flow, temperature and skin color were analyzed using laser-speckle contrast imaging, infrared and polarized-light colorimetry following cold-hand immersion (CHI) challenge in patients with cold-induced urticaria compared to the response in healthy controls. Evidence for mast cell degranulation was established by documentation of serum histamine levels and the localized release of tryptase in post-challenge urticarial biopsies. Laser-speckle contrast imaging quantified the attenuated response to cold challenge in patients on cetirizine. We found that the histamine-associated vascular response accompanying mast cell degranulation is rapid and extensive. At the tissue level, it is characterized by a uniform pattern of increased blood flow, thermal warming, vasodilation, and recruitment of collateral circulation. These vascular responses are modified by the administration of an antihistamine. Conclusions/Significance Monitoring the hemodynamic responses within tissues that are associated with mast cell degranulation provides additional insight into the evolution of the acute inflammatory response and offers a unique approach to assess the effectiveness of treatment intervention. PMID:23451084

30 CFR 77.807-2 - Booms and masts; minimum distance from high-voltage lines.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-voltage lines. 77.807-2 Section 77.807-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... WORK AREAS OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.807-2 Booms and masts; minimum distance from high-voltage lines. The booms and masts of equipment operated on the surface of any...

HMC-1 human mast cells synthesize neurotensin (NT) precursor, secrete bioactive NT-like peptide(s) and express NT receptor NTS1.

PubMed

Cochrane, David E; Carraway, Robert E; Harrington, Kimberly; Laudano, Melissa; Rawlings, Stephen; Feldberg, Ross S

2011-12-01

To determine if mast cells synthesize the inflammatory peptide, neurotensin (NT), secrete immunoreactive and bioactive NT, and express the NT receptor NTS1. HMC-1 cells, pleural mast cells from Sprague-Dawley rats, LAD2 mast cells, and human cord blood mast cells were used. HMC-1 cells were stimulated with NT, C48/80, mastoparan, or PGE(2). For changes in cutaneous vascular permeability, anesthetized rats were injected intravenously with Evans Blue dye and intradermally with saline, NT, histamine, diphenhydramine, and C48/80. RT-PCR was used to identify RNA transcripts. Histamine was measured by fluorometric assay. In vivo cutaneous vascular permeability assays, radio-immunoassays for NT, Western blotting for the NT precursor protein and NTS1 protein from HMC-1 cells and tissues from rats were used. Immunohistochemistry was used to identify NT precursor-like proteins in HMC-1 mast cells. HMC-1 cells express mRNAs for NT precursor, PC5A processing enzyme and NTS1 receptor. Human cord blood mast cells and LAD2 mast cells express mRNA transcripts for NT precursor and NTS1. Western blotting showed NT precursor and NTS1 receptor in HMC1. Rat tissues with high numbers of mast cells contained NT precursor proteins. NT-like peptides from HMC-1 displayed NT-like bioactivity. HMC-1 mast cells synthesize and secrete immunoreactive and bioactive NT-like peptide(s) and express the NT receptor, suggesting that NT from mast cells might serve autocrine and paracrine roles.

KENNEDY SPACE CENTER, FLA. - Inside the cab of crawler-transporter (CT) number 2, driver Sam Dove, with United Space Alliance, operates the vehicle on a test run to the launch pad. The CT recently underwent modifications to the cab. The CT is transporting a Mobile Launch Platform (MLP). The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

NASA Image and Video Library

2003-08-18

KENNEDY SPACE CENTER, FLA. - Inside the cab of crawler-transporter (CT) number 2, driver Sam Dove, with United Space Alliance, operates the vehicle on a test run to the launch pad. The CT recently underwent modifications to the cab. The CT is transporting a Mobile Launch Platform (MLP). The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

Model Calibration Efforts for the International Space Station's Solar Array Mast

NASA Technical Reports Server (NTRS)

Elliott, Kenny B.; Horta, Lucas G.; Templeton, Justin D.; Knight, Norman F., Jr.

2012-01-01

The International Space Station (ISS) relies on sixteen solar-voltaic blankets to provide electrical power to the station. Each pair of blankets is supported by a deployable boom called the Folding Articulated Square Truss Mast (FAST Mast). At certain ISS attitudes, the solar arrays can be positioned in such a way that shadowing of either one or three longerons causes an unexpected asymmetric thermal loading that if unchecked can exceed the operational stability limits of the mast. Work in this paper documents part of an independent NASA Engineering and Safety Center effort to assess the existing operational limits. Because of the complexity of the system, the problem is being worked using a building-block progression from components (longerons), to units (single or multiple bays), to assembly (full mast). The paper presents results from efforts to calibrate the longeron components. The work includes experimental testing of two types of longerons (straight and tapered), development of Finite Element (FE) models, development of parameter uncertainty models, and the establishment of a calibration and validation process to demonstrate adequacy of the models. Models in the context of this paper refer to both FE model and probabilistic parameter models. Results from model calibration of the straight longerons show that the model is capable of predicting the mean load, axial strain, and bending strain. For validation, parameter values obtained from calibration of straight longerons are used to validate experimental results for the tapered longerons.

Establishment and characterization of mouse bone marrow-derived mast cell hybridomas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kawahara, Takeshi, E-mail: tkawafb@shinshu-u.ac.jp

2012-11-01

Interleukin (IL)-3-dependent mouse bone marrow-derived mast cells (BMMCs) are an important model for studying the function of mucosal-type mast cells. In the present study, BMMCs were successfully immortalized by cell fusion using a hypoxanthine-aminopterin-thymidine medium-sensitive variant of P815 mouse mastocytoma (P815-6TgR) as a partner cell line. The established mouse mast cell hybridomas (MMCHs) expressed {alpha}, {beta}, and {gamma} subunits of high-affinity immunoglobulin E (IgE) receptor (Fc{epsilon}RI) and possessed cytoplasmic granules devoid of or partially filled with electron-dense material. Four independent MMCH clones continuously proliferated without supplemental exogenous IL-3 and showed a degranulation response on stimulation with IgE+antigen. Furthermore, histamine synthesismore » and release by degranulation were confirmed in MMCH-D5, a MMCH clone that showed the strongest degranulation response. MMCH-D5 exhibited elevated levels of IL-3, IL-4, IL-13, granulocyte-macrophage colony-stimulating factor, tumor necrosis factor (TNF)-{alpha}, and cyclooxygenase 2, and production of prostaglandin D{sub 2} and leukotriene C{sub 4} in response to IgE-induced stimulation. MMCH clones also expressed Toll-like receptors (TLRs) 1, 2, 4, and 6 and showed elevated levels of TNF-{alpha} expression in response to stimulation with TLR2 and TLR4 ligands. The MMCHs established using this method should be suitable for studies on Fc{epsilon}RI- and TLR-mediated effector functions of mast cells.« less

Advantages of masting in European beech: timing of granivore satiation and benefits of seed caching support the predator dispersal hypothesis.

PubMed

Zwolak, Rafał; Bogdziewicz, Michał; Wróbel, Aleksandra; Crone, Elizabeth E

2016-03-01

The predator satiation and predator dispersal hypotheses provide alternative explanations for masting. Both assume satiation of seed-eating vertebrates. They differ in whether satiation occurs before or after seed removal and caching by granivores (predator satiation and predator dispersal, respectively). This difference is largely unrecognized, but it is demographically important because cached seeds are dispersed and often have a microsite advantage over nondispersed seeds. We conducted rodent exclosure experiments in two mast and two nonmast years to test predictions of the predator dispersal hypothesis in our study system of yellow-necked mice (Apodemus flavicollis) and European beech (Fagus sylvatica). Specifically, we tested whether the fraction of seeds removed from the forest floor is similar during mast and nonmast years (i.e., lack of satiation before seed caching), whether masting decreases the removal of cached seeds (i.e., satiation after seed storage), and whether seed caching increases the probability of seedling emergence. We found that masting did not result in satiation at the seed removal stage. However, masting decreased the removal of cached seeds, and seed caching dramatically increased the probability of seedling emergence relative to noncached seeds. European beech thus benefits from masting through the satiation of scatterhoarders that occurs only after seeds are removed and cached. Although these findings do not exclude other evolutionary advantages of beech masting, they indicate that fitness benefits of masting extend beyond the most commonly considered advantages of predator satiation and increased pollination efficiency.

A mast-seeding desert shrub regulates population dynamics and behavior of its heteromyid dispersers

Treesearch

Janene Auger; Susan E. Meyer; Stephen H. Jenkins

2016-01-01

Granivorous rodent populations in deserts are primarily regulated through precipitation-driven resource pulses rather than pulses associated with mast-seeding, a pattern more common in mesic habitats. We studied heteromyid responses to mast-seeding in the desert shrub blackbrush (Coleogyne ramosissima), a regionally dominant species in the Mojave–Great Basin...

Beyond apoptosis: the mechanism and function of phosphatidylserine asymmetry in the membrane of activating mast cells.

PubMed

Rysavy, Noel M; Shimoda, Lori M N; Dixon, Alyssa M; Speck, Mark; Stokes, Alexander J; Turner, Helen; Umemoto, Eric Y

2014-01-01

Loss of plasma membrane asymmetry is a hallmark of apoptosis, but lipid bilayer asymmetry and loss of asymmetry can contribute to numerous cellular functions and responses that are independent of programmed cell death. Exofacial exposure of phosphatidylserine occurs in lymphocytes and mast cells after antigenic stimulation and in the absence of apoptosis, suggesting that there is a functional requirement for phosphatidylserine exposure in immunocytes. In this review we examine current ideas as to the nature of this functional role in mast cell activation. Mechanistically, there is controversy as to the candidate proteins responsible for phosphatidylserine translocation from the internal to external leaflet, and here we review the candidacies of mast cell PLSCR1 and TMEM16F. Finally we examine the potential relationship between functionally important mast cell membrane perturbations and phosphatidylserine exposure during activation.

Monitoring black-tailed prairie dog colonies with high-resolution satellite imagery

USGS Publications Warehouse

Sidle, John G.; Johnson, D.H.; Euliss, B.R.; Tooze, M.

2002-01-01

The United States Fish and Wildlife Service has determined that the black-tailed prairie dog (Cynomys ludovicianus) warrants listing as a threatened species under the Endangered Species Act. Central to any conservation planning for the black-tailed prairie dog is an appropriate detection and monitoring technique. Because coarse-resolution satellite imagery is not adequate to detect black-tailed prairie dog colonies, we examined the usefulness of recently available high-resolution (1-m) satellite imagery. In 6 purchased scenes of national grasslands, we were easily able to visually detect small and large colonies without using image-processing algorithms. The Ikonos (Space Imaging(tm)) satellite imagery was as adequate as large-scale aerial photography to delineate colonies. Based on the high quality of imagery, we discuss a possible monitoring program for black-tailed prairie dog colonies throughout the Great Plains, using the species' distribution in North Dakota as an example. Monitoring plots could be established and imagery acquired periodically to track the expansion and contraction of colonies.

Increased mast cell numbers in a calcaneal tendon overuse model.

PubMed

Pingel, J; Wienecke, J; Kongsgaard, M; Behzad, H; Abraham, T; Langberg, H; Scott, A

2013-12-01

Tendinopathy is often discovered late because the initial development of tendon pathology is asymptomatic. The aim of this study was to examine the potential role of mast cell involvement in early tendinopathy using a high-intensity uphill running (HIUR) exercise model. Twenty-four male Wistar rats were divided in two groups: running group (n = 12); sedentary control group (n = 12). The running-group was exposed to the HIUR exercise protocol for 7 weeks. The calcaneal tendons of both hind limbs were dissected. The right tendon was used for histologic analysis using Bonar score, immunohistochemistry, and second harmonic generation microscopy (SHGM). The left tendon was used for quantitative polymerase chain reaction (qPCR) analysis. An increased tendon cell density in the runners were observed compared to the controls (P = 0.05). Further, the intensity of immunostaining of protein kinase B, P = 0.03; 2.75 ± 0.54 vs 1.17 ± 0.53, was increased in the runners. The Bonar score (P = 0.05), and the number of mast cells (P = 0.02) were significantly higher in the runners compared to the controls. Furthermore, SHGM showed focal collagen disorganization in the runners, and reduced collagen density (P = 0.03). IL-3 mRNA levels were correlated with mast cell number in sedentary animals. The qPCR analysis showed no significant differences between the groups in the other analyzed targets. The current study demonstrates that 7-week HIUR causes structural changes in the calcaneal tendon, and further that these changes are associated with an increased mast cell density. © 2013 The Authors. Scand J Med Sci Sports published by John Wiley & Sons Ltd.

Elevated blood histamine levels and mast cell degranulation in solar urticaria.

PubMed Central

Hawk, J L; Eady, R A; Challoner, A V; Kobza-Black, A; Keahey, T M; Greaves, M W

1980-01-01

1 Ultraviolet radiation (UVR)-induced wealing was studied in four patients with solar urticaria, whose measured action spectra were within the range 300 to 700 nm. 2 Elevated histamine levels were found in blood draining wealed skin in all four patients. 3 Histological and electron microscopial studies of the irradiated skin showed evidence of mast cell degranulation. 4 These findings demonstrate an association between histamine release from mast cells and wealing in solar urticaria, and should encourage evaluation of drugs which suppress histamine release in this disorder. Images Figure 2 PMID:7356907

Recovery from desensitization of IgE-dependent responses in human lung mast cells.

PubMed

Lewis, A; MacGlashan, D W; Suvarna, S K; Peachell, P T

2017-08-01

Clinical desensitization and oral food immunotherapy are therapeutic interventions that allow individuals who react adversely to an allergen (drug or food) to be made tolerant to the allergen. However, tolerance is brief, and allergen hypersensitivity can recur within days following allergen withdrawal. We hypothesize that the reason these treatments are temporary reflects rapid recovery of mast cells from a desensitized state. We sought to test this. Desensitization of IgE-mediated histamine release from human lung mast cells was explored by methods that partially replicate the pattern of treatment during clinical desensitization. Specific and non-specific desensitization and changes in surface IgE were examined following desensitization. Recovery from desensitization was also studied. Desensitization of mast cell responses was readily induced with concentrations of antigen or anti-IgE that were suboptimal for secretion. There was little or no non-specific desensitization when lung mast cells were exposed to antigens. There was no loss of cell surface IgE following desensitization. Removing the desensitizing stimulus from the media following desensitization allowed the cells to recover with half-point of recovery of ~1.5 days and complete recovery after 5 days. Both the functional response and histamine content recovered within this time frame. The recovery appeared possible because both antigens and anti-IgE dissociated rapidly from cells after washing to remove excess stimulus. Human lung mast cells readily recover from a desensitized state following removal of desensitizing antigen. This finding provides a potential explanation for the ephemeral nature of clinical desensitization. © 2017 John Wiley & Sons Ltd.

Substance P and vasoactive intestinal peptide degradation by mast cell tryptase and chymase.

PubMed

Caughey, G H; Leidig, F; Viro, N F; Nadel, J A

1988-01-01

The peptides substance P (SP) and vasoactive intestinal peptide (VIP) released from peptidergic neurons have potent effects on gland secretion and on smooth muscle tone. Because mast cells release proteases during degranulation, and are located in many of the same tissue microenvironments into which SP and VIP are released, we wished to examine whether mast cell proteases, by cleaving and thus inactivating these peptides, could modulate their effects. We used active site-titrated preparations of the two major neutral proteases of mast cell granules, tryptase and chymase, to determine the sites and rates of cleavage of SP and VIP. The proteases were purified from dog mastocytomas. Tryptase cleaved VIP rapidly at two sites with a kcat/Km of 2.2 X 10(5) sec-1 M-1, but had no effect on SP. Chymase cleaved both SP and VIP at primarily a single site with kcat/Km of 3.9 X 10(4) and 5.4 X 10(4) sec-1 M-1, respectively. Thus, these data show that mast cell proteases degrade SP and VIP. The differences in peptidase activity between tryptase and chymase suggest that the consequences of protease release could vary according to mast cell protease phenotype and location in various tissues and species. Tryptase, by cleaving the bronchodilator VIP but not the bronchoconstrictor SP, might promote bronchial hyper-responsiveness in asthma by decreasing the nonadrenergic neural inhibitory influence mediated by VIP. In skin and other tissues, chymase might interrupt axon reflex-mediated neurogenic inflammation by cleaving SP.

Mediators of mast cells in bullous pemphigoid and dermatitis herpetiformis.

PubMed

Zebrowska, Agnieszka; Wagrowska-Danilewicz, Malgorzata; Danilewicz, Marian; Stasikowska-Kanicka, Olga; Kulczycka-Siennicka, Lilianna; Wozniacka, Anna; Waszczykowska, Elzbieta

2014-01-01

Bullous pemphigoid (BP) and dermatitis herpetiformis (DH) are skin diseases associated with inflammation. However, few findings exist concerning the role of mast cells in autoimmune blistering disease. Skin biopsies were taken from 27 BP and 14 DH patients, as well as 20 healthy individuals. Immunohistochemistry was used to identify the localization and mast cell expression of TNFα and MMP9 in skin lesions and perilesional skin. The serum concentrations of TNFα, MMP9, chymase, tryptase, PAF, and IL-4 were measured by immunoassay. TNFα and MMP9 expression in the epidermis and in inflammatory influxed cells in the dermis was detected in skin biopsies from patients. Although these mediators were found to be expressed in the perilesional skin of all patients, the level was much lower than that in lesional skin. Increased serum PAF levels were observed in BP patients. Mast cells may play an essential role in activating inflammation, which ultimately contributes to the tissue damage observed in BP and DH. Our findings suggest that differences in the pattern of cytokine expression directly contribute to variations in cellular infiltration in DH and BP.

Mediators of Mast Cells in Bullous Pemphigoid and Dermatitis Herpetiformis

PubMed Central

Stasikowska-Kanicka, Olga; Kulczycka-Siennicka, Lilianna; Wozniacka, Anna; Waszczykowska, Elzbieta

2014-01-01

Bullous pemphigoid (BP) and dermatitis herpetiformis (DH) are skin diseases associated with inflammation. However, few findings exist concerning the role of mast cells in autoimmune blistering disease. Skin biopsies were taken from 27 BP and 14 DH patients, as well as 20 healthy individuals. Immunohistochemistry was used to identify the localization and mast cell expression of TNFα and MMP9 in skin lesions and perilesional skin. The serum concentrations of TNFα, MMP9, chymase, tryptase, PAF, and IL-4 were measured by immunoassay. TNFα and MMP9 expression in the epidermis and in inflammatory influxed cells in the dermis was detected in skin biopsies from patients. Although these mediators were found to be expressed in the perilesional skin of all patients, the level was much lower than that in lesional skin. Increased serum PAF levels were observed in BP patients. Mast cells may play an essential role in activating inflammation, which ultimately contributes to the tissue damage observed in BP and DH. Our findings suggest that differences in the pattern of cytokine expression directly contribute to variations in cellular infiltration in DH and BP. PMID:25400334

[Effect of a proteinase-activated receptor-2 (PAR-2) agonist on tryptase release from human mast cells].

PubMed

He, Shao-Heng; Xie, Hua; He, Yong-Song

2002-12-25

Proteinase-activated receptor-2 (PAR-2) expression has been observed on numerous cell types. However, little is known about the functional expression of PAR-2 in human mast cells. In the current study, the actions of a PAR-2 agonist trans-cinnamoyl-Leu-Ile-Gly-Arg-Leu-Orn-amide (tc-LIGRLO) on tryptase release from dispersed human colonic mast cells were examined. The results showed that tc-LIGRLO was able to induce a fold increase in tryptase release over the basal level following a 15 min incubation of colonic mast cells, whereas tc-OLRGIL did not have any effect on tryptase release. The potency of tc-LIGRLO appeared greater than that of anti-IgE and calcium ionophore A23187 (CI) in induction of tryptase release. Extending the incubation time to 30 min had no significant effect on the actions of tc-LIGRLO or anti-IgE. In the time course study, it was observed that the tryptase release from mast cells induced by tc-LIGRLO started at 1 min and peaked at 3 min following incubation. The above-mentioned results indicate that tc-LIGRLO is a potent stimulus of tryptase release from human mast cells, which strongly suggests that PAR-2s are expressed in human mast cells.

A new automated multiple allergen simultaneous test-chemiluminescent assay (MAST-CLA) using an AP720S analyzer.

PubMed

Lee, Sungsil; Lim, Hwan Sub; Park, Jungyong; Kim, Hyon Suk

2009-04-01

In the diagnosis of atopic diseases, allergen detection is a crucial step. Multiple allergen simultaneous test-chemiluminescent assay (MAST-CLA) is a simple and noninvasive method for in vitro screening of allergen-specific IgE antibodies. The Korean Inhalant Panel test on 20 patients and Food Panel test on 19 patients were performed using the conventional manual MAST-CLA kit and the new automated MAST-CLA method (automated AP720S system for the Optigen Assay; Hitachi Chemical Diagnostics, Inc., USA) simultaneously. The results were evaluated for positive reactivity and concordance. The results of inhalant panel gave a relatively higher class level result than the food panel. The 8 patients out of 20 (40%) of the inhalation panel, and 9 patients out of 18 (47.4%) of the food panel showed 100% concordance between the 2 systems. Eighteen patients (90%) of the Inhalation Panel and sixteen patients (84.2%) of the Food Panel showed more than 91% concordance. These results suggest that the MAST-CLA assay using the new, automated AP720S analyzer performs well, showing a high concordance rate with conventional MAST-CLA. Compared to manual MAST-CLA, the automated AP720S system has a shorter assay time and uses a smaller serum volume (500 microl) along with other conveniences.

A Tale of Two Tails: Exploring Stellar Populations in the Tidal Tails of NGC 3256

NASA Astrophysics Data System (ADS)

Rodruck, Michael; Charlton, Jane C.; Konstantopoulos, Iraklis

2016-01-01

Galaxy interactions can inject material into the intergalactic medium via violent gravitational dynamics, often visualized in tidal tails. The composition of these tails has remained a mystery, as previous studies have focused on detecting tidal features, rather than the composite material itself. We have developed an observing program using deep, multiband imaging to probe the chaotic regions of tidal tails in search for an underlying stellar population. NGC 3256's twin tidal tails serve as a case study for this new technique. Our results show color values of u - g = 1.15 and r - i = 0.08 for the Western tail, and u - g = 1.33 and r - i = 0.22 for the Eastern tail, corresponding to discrepant ages between the tails of approximately 320 Myr and 785 Myr, respectively. With the interaction age of the system measured at 400 Myr, we find the stellar light in Western tail to be dominated by disrupted star clusters formed during and after the interaction, whereas the light from the Eastern tail is dominated by a 10 Gyr population originating from the host galaxies. We fit the Eastern tail color to a Mixed Stellar Population (MSP) model comprised 94% by mass of a 10 Gyr stellar population, and 6% of a 309 Myr population. We find 52% of the bolometric flux originating from this 10 Gyr population. We also detect a blue to red color gradient in each tail, running from galactic center to tail tip. In addition to tidal tail light, we detect 29 star cluster candidates (SCCs) in the Western tail and 19 in the Eastern, with mean ages of 282 Myr and 98 Myr respectively. Interestingly, we find an excess of very blue SCCs in the Eastern tail as compared to the Western tail, marking a recent, small episode of star formation.

Conceptual design of a neutron camera for MAST Upgrade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weiszflog, M., E-mail: matthias.weiszflog@physics.uu.se; Sangaroon, S.; Cecconello, M.

2014-11-15

This paper presents two different conceptual designs of neutron cameras for Mega Ampere Spherical Tokamak (MAST) Upgrade. The first one consists of two horizontal cameras, one equatorial and one vertically down-shifted by 65 cm. The second design, viewing the plasma in a poloidal section, also consists of two cameras, one radial and the other one with a diagonal view. Design parameters for the different cameras were selected on the basis of neutron transport calculations and on a set of target measurement requirements taking into account the predicted neutron emissivities in the different MAST Upgrade operating scenarios. Based on a comparisonmore » of the cameras’ profile resolving power, the horizontal cameras are suggested as the best option.« less

GPR30 decreases cardiac chymase/angiotensin II by inhibiting local mast cell number

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Zhuo; Department of Cardiology, Jinan Central Hospital, Affiliated with Shandong University, 105 Jiefang Road, Jinan, 250013; Wang, Hao

2015-03-27

Chronic activation of the novel estrogen receptor GPR30 by its agonist G1 mitigates the adverse effects of estrogen (E2) loss on cardiac structure and function. Using the ovariectomized (OVX) mRen2.Lewis rat, an E2-sensitive model of diastolic dysfunction, we found that E2 status is inversely correlated with local cardiac angiotensin II (Ang II) levels, likely via Ang I/chymase-mediated production. Since chymase is released from cardiac mast cells during stress (e.g., volume/pressure overload, inflammation), we hypothesized that GPR30-related cardioprotection after E2 loss might occur through its opposing actions on cardiac mast cell proliferation and chymase production. Using real-time quantitative PCR, immunohistochemistry, andmore » immunoblot analysis, we found mast cell number, chymase expression, and cardiac Ang II levels were significantly increased in the hearts of OVX-compared to ovary-intact mRen2.Lewis rats and the GPR30 agonist G1 (50 mg/kg/day, s.c.) administered for 2 weeks limited the adverse effects of estrogen loss. In vitro studies revealed that GPR30 receptors are expressed in the RBL-2H3 mast cell line and G1 inhibits serum-induced cell proliferation in a dose-dependent manner, as determined by cell counting, BrdU incorporation assay, and Ki-67 staining. Using specific antagonists to estrogen receptors, blockage of GPR30, but not ERα or ERβ, attenuated the inhibitory effects of estrogen on BrdU incorporation in RBL-2H3 cells. Further study of the mechanism underlying the effect on cell proliferation showed that G1 inhibits cyclin-dependent kinase 1 (CDK1) mRNA and protein expression in RBL-2H3 cells in a dose-dependent manner. - Highlights: • GPR30 activation limits mast cell number in hearts from OVX mRen2.Lewis rats. • GPR30 activation decreases cardiac chymase/angiotensin II after estrogen loss. • GPR30 activation inhibits RBL-2H3 mast cell proliferation and CDK1 expression.« less

Application of rat mast cell incubates as a possible short-time test for sensitizing occupational chemicals.

PubMed

Diel, F; Neidhart, B; Oprée, W

1981-01-01

The direct action of sensitizing occupational chemicals (formaldehyde, phenol, phenylhydrazine, p-aminophenol) on rat mast cells was investigated by determination of histamine using HPLC separation and fluorimetric detection. It turned out that dispensed mast cells from immunized and non-immunized Wistar-rats are more sensitive than small-cut lung tissue slices. Passive cutaneous anaphylaxis was negative after a fortnight sensitizing experiment with the here described occupational chemicals. Short-time tests with rat mast cells reflect anaphylactoid response and are suitable for the screening of sensitizing chemicals.

IgE Immune Complexes Stimulate an Increase in Lung Mast Cell Progenitors in a Mouse Model of Allergic Airway Inflammation

PubMed Central

Dahlin, Joakim S.; Ivarsson, Martin A.; Heyman, Birgitta; Hallgren, Jenny

2011-01-01

Mast cell numbers and allergen specific IgE are increased in the lungs of patients with allergic asthma and this can be reproduced in mouse models. The increased number of mast cells is likely due to recruitment of mast cell progenitors that mature in situ. We hypothesized that formation of IgE immune complexes in the lungs of sensitized mice increase the migration of mast cell progenitors to this organ. To study this, a model of allergic airway inflammation where mice were immunized with ovalbumin (OVA) in alum twice followed by three daily intranasal challenges of either OVA coupled to trinitrophenyl (TNP) alone or as immune complexes with IgE-anti-TNP, was used. Mast cell progenitors were quantified by a limiting dilution assay. IgE immune complex challenge of sensitized mice elicited three times more mast cell progenitors per lung than challenge with the same dose of antigen alone. This dose of antigen challenge alone did not increase the levels of mast cell progenitors compared to unchallenged mice. IgE immune complex challenge of sensitized mice also enhanced the frequency of mast cell progenitors per 106 mononuclear cells by 2.1-fold. The enhancement of lung mast cell progenitors by IgE immune complex challenge was lost in FcRγ deficient mice but not in CD23 deficient mice. Our data show that IgE immune complex challenge enhances the number of mast cell progenitors in the lung through activation of an Fc receptor associated with the FcRγ chain. This most likely takes place via activation of FcεRI, although activation via FcγRIV or a combination of the two receptors cannot be excluded. IgE immune complex-mediated enhancement of lung MCp numbers is a new reason to target IgE in therapies against allergic asthma. PMID:21625525

Nanotextured titanium surfaces stimulate spreading, migration, and growth of rat mast cells.

PubMed

Marcatti Amarú Maximiano, William; Marino Mazucato, Vivian; Tambasco de Oliveira, Paulo; Célia Jamur, Maria; Oliver, Constance

2017-08-01

Titanium is a biomaterial widely used in dental and orthopedic implants. Since tissue-implant interactions occur at the nanoscale level, nanotextured titanium surfaces may affect cellular activity and modulate the tissue response that occurs at the tissue-implant interface. Therefore, the characterization of diverse cell types in response to titanium surfaces with nanotopography is important for the rational design of implants. Mast cells are multifunctional cells of the immune system that release a range of chemical mediators involved in the inflammatory response that occurs at the tissue-implant interface. Therefore, the aim of this study was to investigate the effects of the nanotopography of titanium surfaces on the physiology of mast cells. The results show that the nanotopography of titanium surfaces promoted the spreading of mast cells, which was accompanied by the reorganization of the cytoskeleton. Also, the nanotopography of titanium surfaces enhanced cell migration and cell growth, but did not alter the number of adherent cells in first hours of culture or affect focal adhesions and mediator release. Thus, the results show that nanotopography of titanium surfaces can affect mast cell physiology, and represents an improved strategy for the rational production of surfaces that stimulate tissue integration with the titanium implants. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2150-2161, 2017. © 2017 Wiley Periodicals, Inc.

Test of electical resistivity and current diffusion modelling on MAST and JET

NASA Astrophysics Data System (ADS)

Keeling, D. L.; Challis, C. D.; Jenkins, I.; Hawkes, N. C.; Lupelli, I.; Michael, C.; de Bock, M. F. M.; the MAST Team; contributors, JET

2018-01-01

Experiments have been carried out on the MAST and JET tokamaks intended to compare the electrical resistivity of the plasma with theoretical formulations. The tests consist of obtaining motional stark effect (MSE) measurements in MHD-free plasmas during plasma current ramp-up (JET and MAST), ramp-down (MAST) and in stationary state (JET and MAST). Simulations of these plasmas are then performed in which the current profile evolution is calculated according to the poloidal field diffusion equation (PFDE) with classical or neoclassical resistivity. Synthetic MSE data are produced in the simulations for direct comparison with the experimental data. It is found that the toroidal current profile evolution modelled using neoclassical resistivity did not match the experimental observations on either device during current ramp-up or ramp-down as concluded from comparison of experimental and synthetic MSE profiles. In these phases, use of neoclassical resistivity in the modelling systematically overestimates the rate of current profile evolution. During the stationary state however, the modelled toroidal current profile matched experimental observations to a high degree of accuracy on both devices using neoclassical resistivity. Whilst no solution to the mismatch in the dynamic phases of the plasma is proposed, it is suggested that some physical process other than MHD which is not captured by the simple diffusive model of current profile evolution is responsible.

Effect of LED phototherapy (λ630 +/- 20nm) on mast cells during wound healing in hypothyroid

NASA Astrophysics Data System (ADS)

Paraguassú, Gardênia M.; De Castro, Isabele Cardoso V.; Vasconcelos, Rebeca M.; da Guarda, Milena G.; Rodriguez, Tânia T.; Ramalho, Maria José P.; Pinheiro, Antônio Luiz B.; Ramalho, Luciana Maria P.

2014-02-01

Hypothyroidism has been associated with the disruption of the body's metabolism, including the healing process. LED phototherapy has been studied using several healing models, but their effects on mast cells proliferation associated to hypothyroidism remains unknown. The aim of this study was to assess the effect LED (λ630+/-20nm) phototherapy on mast cells proliferation during tissue repair in hypothyroid rats. Under general anesthesia, a standard surgical wound (1cm2) was created on the dorsum of 24 male Wistar rats divided into 4 groups of 6 animals each: EC-Control Euthyroid; ED-Euthyroid+LED; HC-Control Hypothyroid and HD-Hypothyroid+LED. The irradiation started immediately after surgery and was repeated every other day for 7 days, when animals death occurred. Hypothyroidism was induced in rats with propylthiouracil (0.05g/100mL) administered orally for 4 weeks and maintained until the end of the experiment. The specimens removed were processed to wax and stained with toluidine blue for mast cell identification. The mast cell proliferation was significantly higher in HC group than in EC group (Mann Whitney, p<0.05), but when ED group was compared to HD group, no significant difference was found. Our results showed that there was increase of mast cells in the presence of hypothyroidism, prolonging the inflammatory phase of repair, and the LED light has a biomodulative effect on mast cell population, even when hipothyroidism was present.

Characterization of a mast cell line that lacks the extracellular domain of membrane c-kit.

PubMed

Mekori, Y A; Oh, C K; Dastych, J; Goff, J P; Adachi, S; Bianchine, P J; Worobec, A; Semere, T; Pierce, J H; Metcalfe, D D

1997-04-01

Expression of the c-kit proto-oncogene receptor on mast cells is essential for their normal proliferation and maturation as well as for several biological responses such as chemotaxis and attachment. In the present study we report that the interleukin-3 (IL-3)-dependent mast cell line CFTL-15 lacks the extracellular domain of the c-kit receptor. This observation was made after noting that the c-kit ligand stem cell factor (SCF) could not prevent IL-3 deprivation-induced mast cell apoptosis and that CFTL-15 cells did not proliferate in response to SCF. Flow cytometric analysis employing monoclonal anti-c-kit antibodies, and immunogold labelling with analysis by electron microscopy, subsequently showed a diminished expression of c-kit on CFTL-15 cells. There was no identifiable message for the extracellular domain of c-kit in these cells, as determined by reverse transcriptase-polymerase chain reaction (RT-PCR). These previously unrecognized properties of the CFTL-15 mast cell line allowed the examination of other biological consequences of the lack of c-kit on mast cells. Analysing the ability of these cells to adhere to surface-bound fibronectin, it was found that addition of SCF did not increase their adhesion to this substrate, in opposition to what is reported with other mast cells. Similarly, CFTL-15 mast cells did not adhere to fibroblasts, which is known to require c-kit expression. Also, there was no protein tyrosine phosphorylation in these cells in response to SCF. CFTL-15 cells underwent apoptosis on removal of IL-3 coincident with a decrease in endogenous Bcl-2 mRNA. Overexpression of Bcl-2 cDNA prolonged survival of Bcl-2-transfected CFTL-15 cells upon withdrawal of IL-3. Thus, the CFTL-15 cell line that lacks surface c-kit is not able to proliferate in response to SCF, undergoes apoptosis in the presence of SCF, and does not adhere to fibroblasts. These results confirm earlier studies on the functional consequences of c-kit and provide a novel

Beyond apoptosis: The mechanism and function of phosphatidylserine asymmetry in the membrane of activating mast cells

PubMed Central

Rysavy, Noel M.; Shimoda, Lori M. N.; Dixon, Alyssa M.; Speck, Mark; Stokes, Alexander J.; Turner, Helen; Umemoto, Eric Y.

2014-01-01

Loss of plasma membrane asymmetry is a hallmark of apoptosis, but lipid bilayer asymmetry and loss of asymmetry can contribute to numerous cellular functions and responses that are independent of programmed cell death. Exofacial exposure of phosphatidylserine occurs in lymphocytes and mast cells after antigenic stimulation and in the absence of apoptosis, suggesting that there is a functional requirement for phosphatidylserine exposure in immunocytes. In this review we examine current ideas as to the nature of this functional role in mast cell activation. Mechanistically, there is controversy as to the candidate proteins responsible for phosphatidylserine translocation from the internal to external leaflet, and here we review the candidacies of mast cell PLSCR1 and TMEM16F. Finally we examine the potential relationship between functionally important mast cell membrane perturbations and phosphatidylserine exposure during activation. PMID:25759911

Mast fruiting of large ectomycorrhizal African rain forest trees: importance of dry season intensity, and the resource-limitation hypothesis.

PubMed

Newbery, David M; Chuyong, George B; Zimmermann, Lukas

2006-01-01

Mast fruiting is a distinctive reproductive trait in trees. This rain forest study, at a nutrient-poor site with a seasonal climate in tropical Africa, provides new insights into the causes of this mode of phenological patterning. At Korup, Cameroon, 150 trees of the large, ectomycorrhizal caesalp, Microberlinia bisulcata, were recorded almost monthly for leafing, flowering and fruiting during 1995-2000. The series was extended to 1988-2004 with less detailed data. Individual transitions in phenology were analysed. Masting occurred when the dry season before fruiting was drier, and the one before that was wetter, than average. Intervals between events were usually 2 or 3 yr. Masting was associated with early leaf exchange, followed by mass flowering, and was highly synchronous in the population. Trees at higher elevation showed more fruiting. Output declined between 1995 and 2000. Mast fruiting in M. bisulcata appears to be driven by climate variation and is regulated by internal tree processes. The resource-limitation hypothesis was supported. An 'alternative bearing' system seems to underlie masting. That ectomycorrhizal habit facilitates masting in trees is strongly implied.

Utility of Fite-Faraco stain for both mast cell count and bacillary index in skin biopsies of leprosy patients.

PubMed

Chatura, K R; Sangeetha, S

2012-01-01

To assess the utility of a single stain for both mast cell count and bacillary index (BI), 50 skin-biopsie patients were stained with Fite-Faraco (FF) stain, viewed under oil immersion and BI calculated using the Ridley's logarithmic scale, and mast cells counted as the number of cells per mm2. Mean mast cell count per mm2 at the tuberculoid pole was lowest in TT 7.9 and highest in BT 14.23. At the lepromatous end, it was highest in BL 9.21, while in LL it was 8.23. Highest counts were seen in the borderline types overall. The correlation coefficient between histopathological diagnosis and BI is 0.822 which is a positive correlation to a significant degree. The correlation coefficient between histopathological diagnosis and mast cell count was found to be -0.17, which is a negative correlation but not to a significant degree. FF stain was utilised to visualise both bacilli for estimation of BI and mast cells for mast cell count, a seldom attempted feature in literature.

Acute infection with the intestinal parasite Trichuris muris has long-term consequences on mucosal mast cell homeostasis and epithelial integrity.

PubMed

Sorobetea, Daniel; Holm, Jacob Bak; Henningsson, Henrietta; Kristiansen, Karsten; Svensson-Frej, Marcus

2017-02-01

A hallmark of parasite infection is the accumulation of innate immune cells, notably granulocytes and mast cells, at the site of infection. While this is typically viewed as a transient response, with the tissue returning to steady state once the infection is cleared, we found that mast cells accumulated in the large-intestinal epithelium following infection with the nematode Trichuris muris and persisted at this site for several months after worm expulsion. Mast cell accumulation in the epithelium was associated with the induction of type-2 immunity and appeared to be driven by increased maturation of local progenitors in the intestinal lamina propria. Furthermore, we also detected increased local and systemic levels of the mucosal mast cell protease MCPt-1, which correlated highly with the persistent epithelial mast cell population. Finally, the mast cells appeared to have striking consequences on epithelial barrier integrity, by regulation of gut permeability long after worm expulsion. These findings highlight the importance of mast cells not only in the early phases of infection but also at later stages, which has functional implications on the mucosal tissue. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

IL-10 Enhances IgE-Mediated Mast Cell Responses and Is Essential for the Development of Experimental Food Allergy in IL-10-Deficient Mice.

PubMed

Polukort, Stephanie H; Rovatti, Jeffrey; Carlson, Logan; Thompson, Chelsea; Ser-Dolansky, Jennifer; Kinney, Shannon R M; Schneider, Sallie S; Mathias, Clinton B

2016-06-15

IL-10 is a key pleiotropic cytokine that can both promote and curb Th2-dependent allergic responses. In this study, we demonstrate a novel role for IL-10 in promoting mast cell expansion and the development of IgE-mediated food allergy. Oral OVA challenge in sensitized BALB/c mice resulted in a robust intestinal mast cell response accompanied by allergic diarrhea, mast cell activation, and a predominance of Th2 cytokines, including enhanced IL-10 expression. In contrast, the development of intestinal anaphylaxis, including diarrhea, mast cell activation, and Th2 cytokine production, was significantly attenuated in IL-10(-/-) mice compared with wild-type (WT) controls. IL-10 also directly promoted the expansion, survival, and activation of mast cells; increased FcεRI expression on mast cells; and enhanced the production of mast cell cytokines. IL-10(-/-) mast cells had reduced functional capacity, which could be restored by exogenous IL-10. Similarly, attenuated passive anaphylaxis in IL-10(-/-) mice could be restored by IL-10 administration. The adoptive transfer of WT mast cells restored allergic symptoms in IL-10(-/-) mice, suggesting that the attenuated phenotype observed in these animals is due to a deficiency in IL-10-responding mast cells. Lastly, transfer of WT CD4 T cells also restored allergic diarrhea and intestinal mast cell numbers in IL-10(-/-) mice, suggesting that the regulation of IL-10-mediated intestinal mast cell expansion is T cell dependent. Our observations demonstrate a critical role for IL-10 in driving mucosal mast cell expansion and activation, suggesting that, in its absence, mast cell function is impaired, leading to attenuated food allergy symptoms. Copyright © 2016 by The American Association of Immunologists, Inc.

Evaluation of high mast luminaire lowering devices in Oregon.

DOT National Transportation Integrated Search

1981-09-01

High mast luminaire lowering devices were installed on two projects in Oregon following approval by the Department of Transportation, Federal Highway Administration, of the installations as experimental features projects. Holophane Company, Inc., sup...

Clinical, biological, and molecular characteristics of clonal mast cell disorders presenting with systemic mast cell activation symptoms.

PubMed

Alvarez-Twose, Iván; González de Olano, David; Sánchez-Muñoz, Laura; Matito, Almudena; Esteban-López, Maria I; Vega, Arantza; Mateo, Maria Belén; Alonso Díaz de Durana, Maria D; de la Hoz, Belén; Del Pozo Gil, Maria D; Caballero, Teresa; Rosado, Ana; Sánchez Matas, Isabel; Teodósio, Cristina; Jara-Acevedo, María; Mollejo, Manuela; García-Montero, Andrés; Orfao, Alberto; Escribano, Luis

2010-06-01

Systemic mast cell activation disorders (MCADs) are characterized by severe and systemic mast cell (MC) mediators-related symptoms frequently associated with increased serum baseline tryptase (sBt). To analyze the clinical, biological, and molecular characteristics of adult patients presenting with systemic MC activation symptoms/anaphylaxis in the absence of skin mastocytosis who showed clonal (c) versus nonclonal (nc) MCs and to provide indication criteria for bone marrow (BM) studies. Eighty-three patients were studied. Patients showing clonal BM MCs were grouped into indolent systemic mastocytosis without skin lesions (ISMs(-); n = 48) and other c-MCADs (n = 3)-both with CD25(++) BM MCs and either positive mast/stem cell growth factor receptor gene (KIT) mutation or clonal human androgen receptor assay (HUMARA) tests-and nc-MCAD (CD25-negative BM MCs in the absence of KIT mutation; n = 32) and compared for their clinical, biological, and molecular characteristics. Most clonal patients (48/51; 94%) met the World Health Organization criteria for systemic mastocytosis and were classified as ISMs(-), whereas the other 3 c-MCAD and all nc-MCAD patients did not. In addition, although both patients with ISMs(-) and patients with nc-MCAD presented with idiopathic and allergen-induced anaphylaxis, the former showed a higher frequency of men, cardiovascular symptoms, and insect bite as a trigger, together with greater sBt. Based on a multivariate analysis, a highly efficient model to predict clonality before BM sampling was built that includes male sex (P = .01), presyncopal and/or syncopal episodes (P = .009) in the absence of urticaria and angioedema (P = .003), and sBt >25 microg/L (P = .006) as independent predictive factors. Patients with c-MCAD and ISMs(-) display unique clinical and laboratory features different from nc-MCAD patients. A significant percentage of c-MCAD patients can be considered as true ISMs(-) diagnosed at early phases of the disease. Copyright

Modelling and Analysis Capabilities for Lightweight Masts

DTIC Science & Technology

2001-02-01

manufactured by Astro Aerospace Corporation in Carpinteria, California for NASA’s Johnson Space Center in Houston. The mast structure was a 750 mm...step iii. Design Parameters • Design variables Moduli: E11, E22, E33, G12, G23, G13, ᝼, ជ, ᝽ Strengths: FXT, FXC , FYT, FYC, FZT, FZC, FXY

2D/3D Visual Tracker for Rover Mast

NASA Technical Reports Server (NTRS)

Bajracharya, Max; Madison, Richard W.; Nesnas, Issa A.; Bandari, Esfandiar; Kunz, Clayton; Deans, Matt; Bualat, Maria

2006-01-01

A visual-tracker computer program controls an articulated mast on a Mars rover to keep a designated feature (a target) in view while the rover drives toward the target, avoiding obstacles. Several prior visual-tracker programs have been tested on rover platforms; most require very small and well-estimated motion between consecutive image frames a requirement that is not realistic for a rover on rough terrain. The present visual-tracker program is designed to handle large image motions that lead to significant changes in feature geometry and photometry between frames. When a point is selected in one of the images acquired from stereoscopic cameras on the mast, a stereo triangulation algorithm computes a three-dimensional (3D) location for the target. As the rover moves, its body-mounted cameras feed images to a visual-odometry algorithm, which tracks two-dimensional (2D) corner features and computes their old and new 3D locations. The algorithm rejects points, the 3D motions of which are inconsistent with a rigid-world constraint, and then computes the apparent change in the rover pose (i.e., translation and rotation). The mast pan and tilt angles needed to keep the target centered in the field-of-view of the cameras (thereby minimizing the area over which the 2D-tracking algorithm must operate) are computed from the estimated change in the rover pose, the 3D position of the target feature, and a model of kinematics of the mast. If the motion between the consecutive frames is still large (i.e., 3D tracking was unsuccessful), an adaptive view-based matching technique is applied to the new image. This technique uses correlation-based template matching, in which a feature template is scaled by the ratio between the depth in the original template and the depth of pixels in the new image. This is repeated over the entire search window and the best correlation results indicate the appropriate match. The program could be a core for building application programs for systems

Modelling of Divertor Detachment in MAST Upgrade

NASA Astrophysics Data System (ADS)

Moulton, David; Carr, Matthew; Harrison, James; Meakins, Alex

2017-10-01

MAST Upgrade will have extensive capabilities to explore the benefits of alternative divertor configurations such as the conventional, Super-X, x divertor, snowflake and variants in a single device with closed divertors. Initial experiments will concentrate on exploring the Super-X and conventional configurations, in terms of power and particle loads to divertor surfaces, access to detachment and its control. Simulations have been carried out with the SOLPS5.0 code validated against MAST experiments. The simulations predict that the Super-X configuration has significant advantages over the conventional, such as lower detachment threshold (2-3x lower in terms of upstream density and 4x higher in terms of PSOL). Synthetic spectroscopy diagnostics from these simulations have been created using the Raysect ray tracing code to produce synthetic filtered camera images, spectra and foil bolometer data. Forward modelling of the current set of divertor diagnostics will be presented, together with a discussion of future diagnostics and analysis to improve estimates of the plasma conditions. Work supported by the RCUK Energy Programme [Grant Number EP/P012450/1] and EURATOM.

ChemCam Mast Unit Being Prepared for Laser Firing

NASA Image and Video Library

2010-12-23

Researchers prepare for a test of the Chemistry and Camera ChemCam instrument that will fly on NASA Mars Science Laboratory mission; researchers are preparing the instrument mast unit for a laser firing test.

Further studies on the effect of nitrogen dioxide on mast cells: The effect of the metabolite, nitrite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fujimaki, Hidekazu; Ozawa, Masashi; Bissonnette, E.

1993-05-01

To evaluate the relationship between atmospheric nitrogen dioxide exposure and the development of allergic diseases, the effects of nitrite as a chemical product of inhaled nitrogen dioxide on mast cell functions were investigated. We have studied nitride-induced histamine release from two functionally distinct mast cell populations, namely peritoneal mast cells (PMC) and intestinal mucosal mast cells (IMMC) of Nippostrongylus brasiliensis-infected rats. High concentrations of nitrite alone (10, 20, and 50 mM) induced histamine release from IMMC, but not from PMC. Moreover, histamine release from PMC and IMMC stimulated with sensitizing antigen was significantly enhanced by pretreatment with 50 mM nitritemore » or nitrate. No differences in histamine release from nitrite-treated and control PMC were seen below 1 mM. To investigate the effect of nitrite on tumor cell cytotoxic activity, PMC were incubated with various concentrations of nitrite. Pretreatment with 5 and 50 mM nitrite markedly depressed tumor necrosis factor (TNF)-[alpha]-dependent natural cytotoxicity of PMC for the tumor target WEHI-164. Thus, high concentrations of nitrite enhanced mast cell histamine release, but depressed TNF-[alpha]-dependent cytotoxicity. However, low concentrations of nitrite (<1 mM) that would normally be produced by short-term atmospheric exposure to nitrogen dioxide may have no significant effects on mast cell functions. 27 refs., 3 figs., 1 tab.« less

Deep-Sea-Derived Butyrolactone I Suppresses Ovalbumin-Induced Anaphylaxis by Regulating Mast Cell Function in a Murine Model.

PubMed

Liu, Qing-Mei; Xie, Chun-Lan; Gao, Yuan-Yuan; Liu, Bo; Lin, Wei-Xiang; Liu, Hong; Cao, Min-Jie; Su, Wen-Jin; Yang, Xian-Wen; Liu, Guang-Ming

2018-06-06

Deep-sea-derived butyrolactone I (BTL-I), which was identified as a type of butanolide, was isolated from Aspergillus sp. Ovalbumin (OVA)-induced BALB/c anaphylaxis was established to explore the antifood allergic activity of BTL-I. As a result, BTL-I was able to alleviate OVA-induced allergy symptoms, reduce the levels of histamine and mouse mast cell proteinases, inhibit OVA-specific IgE, and decrease the population of mast cells in the spleen and mesenteric lymph nodes. BTL-I also significantly suppressed mast-dependent passive cutaneous anaphylaxis. Additionally, the maturation of bone marrow-derived mast cells (BMMCs) declined as BTL-I caused down-regulation of c-KIT receptors. Furthermore, molecular docking analyses revealed that BTL-I interacted with the inhibitory receptor, FcγRIIB. In conclusion, the reduction of mast cell function by deep-sea-derived BTL-I as well as its interactions with the inhibitory receptor, FcγRIIB, may contribute to BTL-I-related protection against food anaphylaxis.

Dissecting components of population-level variation in seed production and the evolution of masting behavior.

Treesearch

W. D. Koenig; D. Kelly; V. L. Sork; R. P. Duncan; J. S. Elkinton; M.S. Peltonen; R. D. Westfall

2003-01-01

Mast-fruiting or masting behavior is the cumulative result of the reproductive patterns of individuals within a population and thus involves components of individual variability, between-individual synchrony, and endogenous cycles of temporal autocorrelation. Extending prior work by Herrera, we explore the interrelationships of these components using data on individual...

iMAST Quarterly, Number 4, 1999

DTIC Science & Technology

1999-01-01

ELEMENT NUMBER 6 . AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Penn State... 6 Calendar of Events .............................................. 8 Good-bye We are rapidly approaching the end of 1999 and...U.Ed. ARL 00- 6 DIRECTOR’S CORNER iMAST Quarterly 1999 No. 4 3 FEATURE ARTICLE Focus on Environmentally Friendly Technologies Automated Paint

Leukotriene C4 production by murine mast cells: evidence of a role for extracellular leukotriene A4.

PubMed Central

Dahinden, C A; Clancy, R M; Gross, M; Chiller, J M; Hugli, T E

1985-01-01

The glutathione-containing leukotriene C4 (LTC4) is a major mediator of smooth muscle contraction and is released by mast cells when antigen interacts with cell-bound IgE. Antigen-stimulated mast cells undergo phospholipase activation. We report a pathway of LTC4 production by mast cells that does not require phospholipase activation but depends on the interaction of activated neutrophils with unstimulated mast cells, using as an intermediate extracellular leukotriene A4 (LTA4). The epoxide LTA4 is released by neutrophils and, together with leukotriene B4 and 5-hydroxyeicosatetraenoic acid, constitutes the major lipoxygenase metabolites found in supernatants of stimulated neutrophils. Five minutes after activation of neutrophils by calcium ionophore A23187 we measured 136 pmol of extracellular LTA4 per 10(7) neutrophils (range 40-300, n = 7) by trapping the epoxide with alcohols. Therefore, we conclude that LTA4 is not just an intracellular leukotriene precursor but is released as a lipoxygenase metabolite. LTA4 is known to be stabilized by albumin and is efficiently converted by mast cells into LTC4 even at low LTA4 concentrations. The LTA4 complexed to albumin is converted into LTC4 rapidly and completely within 10-15 min. More than 50% of the LTA4 presented to mast cells is metabolized to LTC4 at concentrations of LTA4 between 0.2 and 2 nmol of LTA4 per 10(7) mast cells. This observation establishes a potential physiologic role for extracellular LTA4. Therefore, interactions between various cell types that release or utilize LTA4 may provide an important metabolic pathway for the production of leukotrienes. PMID:2995976

Cannabinoids reduce granuloma-associated angiogenesis in rats by controlling transcription and expression of mast cell protease-5

PubMed Central

De Filippis, D; Russo, A; D'Amico, A; Esposito, G; Concetta, P; Cinelli, M; Russo, G; Iuvone, T

2008-01-01

Background and purpose: Chronic inflammatory conditions, such as granulomas, are associated with angiogenesis. Mast cells represent the main cell type orchestrating angiogenesis, through the release of their granule content. Therefore, compounds able to modulate mast cell behaviour may be considered as a new pharmacological approach to treat angiogenesis-dependent events. Here, we tested the effect of selective cannabinoid (CB) receptor agonists in a model of angiogenesis-dependent granuloma formation induced by λ-carrageenin in rats. Experimental approach: Granulomas were induced by λ-carrageenin-soaked sponges implanted subcutaneously on the back of male Wistar rats. After 96 h, implants were removed and granuloma formation was measured (wet weight); angiogenesis was evaluated by histological analysis and by the measurement of haemoglobin content. Mast cells in the granulomas were evaluated histologically and by RT-PCR and immunoblotting analysis for mast cell-derived proteins (rat mast cell protease-5 (rMCP-5) and nerve growth factor). Selective CB1 and CB2 receptor agonists, ACEA and JWH-015 (0.001–0.1 mg mL−1), were given locally only once, at the time of implantation. Key results: The CB1 and CB2 receptor agonists decreased the weight and vascularization of granulomas after 96 h. This treatment also reduced mast cell number and activation in granulomatous tissue. Specifically, these compounds prevented the transcription and expression of rMCP-5, a protein involved in sprouting and advance of new blood vessels. Conclusion and implications: Modulation of mast cell function by cannabinoids reduced granuloma formation and associated angiogenesis. Therefore cannabinoid-related drugs may be useful in the management of granulomatous diseases accompanied by angiogenesis. PMID:18552882