Effects of passive inhalation of cigarette smoke on structural and functional parameters in the respiratory system of guinea pigs / Efeitos da inalação passiva da fumaça de cigarro em parâmetros estruturais e funcionais no sistema respiratório de cobaias

ABSTRACT Objective: To evaluate the effects of passive inhalation of cigarette smoke on the respiratory system of guinea pigs. Methods: Male guinea pigs were divided into two groups: control and passive smoking, the latter being exposed to the smoke of ten cigarettes for 20 min in the morning, afternoon and evening (30 cigarettes/day) for five days. After that period, inflammatory parameters were studied by quantifying mesenteric mast cell degranulation, as well as oxidative stress, in BAL fluid. In addition, we determined MIP, MEP, and mucociliary transport (in vivo), as well as tracheal contractility response (in vitro). Results: In comparison with the control group, the passive smoking group showed a significant increase in mast cell degranulation (19.75 ± 3.77% vs. 42.53 ± 0.42%; p < 0.001) and in the levels of reduced glutathione (293.9 ± 19.21 vs. 723.7 ± 67.43 nM/g of tissue; p < 0.05); as well as a significant reduction in mucociliary clearance (p < 0.05), which caused significant changes in pulmonary function (in MIP and MEP; p < 0.05 for both) and airway hyperreactivity. Conclusions: Passive inhalation of cigarette smoke caused significant increases in mast cell degranulation and oxidative stress. This inflammatory process seems to influence the decrease in mucociliary transport and to cause changes in pulmonary function, leading to tracheal hyperreactivity.

RESUMO Objetivo: Avaliar os efeitos da inalação passiva da fumaça de cigarro no sistema respiratório de cobaias. Métodos: Foram utilizadas cobaias machos, divididas em dois grupos: controle e tabagismo passivo, esse último exposto à fumaça de dez cigarros por 20 min pela manhã, tarde e noite (30 cigarros/dia) por 5 dias. Após esse período, parâmetros inflamatórios foram estudados através da contagem de degranulação de mastócitos no mesentério e de estresse oxidativo a partir do LBA. Adicionalmente, foram verificadas PImáx, PEmáx, transporte mucociliar (in vivo) e contratilidade traqueal (in vitro). Resultados: Na comparação com o grupo controle, o grupo tabagismo passivo apresentou um aumento significativo na degranulação de mastócitos (19,75 ± 3,77% vs. 42,53 ± 0,42%; p < 0,001), nos níveis de glutationa reduzida (293,9 ± 19,21 vs. 723,7 ± 67,43 nM/g de tecido; p < 0,05) e uma redução significativa no transporte mucociliar (p < 0,05), provocando alterações significativas na função pulmonar, tanto na PImáx como na PEmáx (p < 0,05 para ambas), e hiper-reatividade nas vias aéreas. Conclusões: A inalação passiva da fumaça de cigarro ocasionou aumentos significativos na degranulação de mastócitos e no estresse oxidativo. Esse processo inflamatório parece ter influenciado a diminuição do transporte mucociliar e causado alterações na função pulmonar, proporcionando um quadro de hiper-reatividade traqueal.

Efectores celulares de la respuesta inflamatoria en la enfermedad pulmonar obstructiva crónica / Cellular effectors of the inflammatory response in chronic obstructive pulmonary disease (COPD)

Approximately 3 million people in the world die every year as a consequence of COPD, which is associated with an abnormal inflammatory response of the lung to noxious particles and gases. This inflammatory pattern causes pathological changes leading to a narrowing of small airways and destruction of lung parenchyma, also known as emphysema. Classically, these changes were associated to macrophages and neutrophils, although T CD8+ lymphocytes were latter added to the equation to explain the origin of emphysematous lesions. However, in recent years, multiple evidences have arisen indicating that inflammatory response in COPD is much more complex. These findings point to a key role for mast cells, dendritic cells, T CD4+ and B cells. The aim of this article is to review such evidence and report what is known so far about those cells involved in the inflammatory response in COPD.

Mecanismos de defesa dos mastócitos contra o periodontopatógeno Aggregatibacter actinomycetemcomitans: atividade microbicida intracelular / Defense mechanisms of mast cells against periodontopathogen Aggregatibacter actinomycetemcomitans: intracellular microbicidal activity

Os mastócitos (MCs) estão presentes tanto no periodonto normal quanto inflamado, em diferentes quantidades e em vários locais. Nos últimos anos, a eficácia e a contribuição dos MCs em eliminar bactérias, através de sua atividade microbicida intracelular, estão se tornando cada vez mais reconhecidas. Assim, a partir de MCs murinos desafiados in vitro com o periodontopatógeno Aggregatibacter actinomycetemcomitans (ATCC 29523) por 3, 5, 10 e 24 horas, o presente estudo teve como objetivo investigar a capacidade microbicida intracelular de MCs, e comparar com a capacidade microbicida de macrófagos peritoneais murinos (MPs), considerados fagócitos profissionais, por meio da contagem das unidades formadoras de colônias. Além disso, avaliou-se a produção e liberação de mediadores microbicidas, óxido nítrico (NO) e peróxido de hidrogênio (H2O2), por meio do método colorimétrico de Griess e pela degradação de substratos fluorescentes, respectivamente. Para a análise estatística, foram utilizados os testes estatísticos ANOVA Fatorial seguido do teste de Tukey e teste de correlação de Pearson (p<0.05). Nossos resultados revelaram que os MCs foram capazes de eliminar eficientemente o periodontopatógeno, principalmente após 10h de desafio intracelular. Comparando-se a atividade microbicida dos dois tipos celulares, verificou-se, nos períodos de 3h e 5h de desafio, um menor percentual de colônias viáveis no interior de MPs, em comparação aos MCs. Inversamente, nos períodos de 10h e 24h, observaram-se menores valores percentuais de colônias intracelulares nos MCs em relação aos MPs. Além disso, a produção/liberação de NO bem como, em menor proporção, de H2O2 pelos MCs foram concordantes com a sua capacidade microbicida. Este é o primeiro estudo que demonstra a eficiente ação microbicida intracelular de MCs murinos contra Aggregatibacter actinomycetemcomitans, com produção e liberação de substâncias potencialmente bactericidas, e de forma mais eficaz que os macrófagos...

Mast cells (MCs) are present in both normal and inflamed periodontal tissues, in varying amounts and locations. Recently, MCs contribution in eliminating bacteria and its effectiveness, through its intracellular microbicidal activity, have been increasingly recognized. Thus, this study aimed to investigate the intracellular microbicide capacity of MCs, and compare it with the microbicide capacity of murine peritoneal macrophages (MPs), considered professional phagocytes, by counting the colony forming units. Both cell types were challenged in vitro with periodontopathogen Aggregatibacter actinomycetemcomitans (ATCC 29523) by 3, 5, 10 and 24 hours. Additionally, the production and release of microbicidal agents, nitric oxide (NO) and hydrogen peroxide (H2O2) were evaluated by means of colorimetric Griess method and by the degradation of fluorescent substrates, respectively. Statistical analysis was performed by ANOVA Factorial test followed by Tukey and Pearson's correlation test (p <0.05). Our results revealed that MCs are able to efficiently eliminate periodontopathogen, mainly after 10 hours of intracellular challenge. The microbicidal activity of both cell types, in 3 and 5 hours of challenge showed a lower percentage of viable colonies inside MPs, compared to MCs. Contradictorily, in 10 and 24 hours a lower percentage of intracellular colonies in MCs was observed in relation to MPs. Moreover, the production/release of NO and, in minor proportion, of H2O2 by MCs was in agreement with its microbicidal capacity. Therefore, this is the first report to describe the intracellular microicidal activity of murine MCs against Aggregatibacter actinomycetemcomitans, concerning production and release of potentially bactericidal substances, which is more effective than macrophages. These results suggest the importance of these cells in pathogenesis and defense mechanisms of biofilm-associated periodontal disease...

Mecanismos de defesa dos mastócitos contra o periodontopatógeno Aggregatibacter actinomycetemcomitans: atividade microbicida intracelular / Defense mechanisms of mast cells against periodontopathogen Aggregatibacter actinomycetemcomitans: intracellular microbicidal activity

Os mastócitos (MCs) estão presentes tanto no periodonto normal quanto inflamado, em diferentes quantidades e em vários locais. Nos últimos anos, a eficácia e a contribuição dos MCs em eliminar bactérias, através de sua atividade microbicida intracelular, estão se tornando cada vez mais reconhecidas. Assim, a partir de MCs murinos desafiados in vitro com o periodontopatógeno Aggregatibacter actinomycetemcomitans (ATCC 29523) por 3, 5, 10 e 24 horas, o presente estudo teve como objetivo investigar a capacidade microbicida intracelular de MCs, e comparar com a capacidade microbicida de macrófagos peritoneais murinos (MPs), considerados fagócitos profissionais, por meio da contagem das unidades formadoras de colônias. Além disso, avaliou-se a produção e liberação de mediadores microbicidas, óxido nítrico (NO) e peróxido de hidrogênio (H2O2), por meio do método colorimétrico de Griess e pela degradação de substratos fluorescentes, respectivamente. Para a análise estatística, foram utilizados os testes estatísticos ANOVA Fatorial seguido do teste de Tukey e teste de correlação de Pearson (p<0.05). Nossos resultados revelaram que os MCs foram capazes de eliminar eficientemente o periodontopatógeno, principalmente após 10h de desafio intracelular. Comparando-se a atividade microbicida dos dois tipos celulares, verificou-se, nos períodos de 3h e 5h de desafio, um menor percentual de colônias viáveis no interior de MPs, em comparação aos MCs. Inversamente, nos períodos de 10h e 24h, observaram-se menores valores percentuais de colônias intracelulares nos MCs em relação aos MPs. Além disso, a produção/liberação de NO bem como, em menor proporção, de H2O2 pelos MCs foram concordantes com a sua capacidade microbicida. Este é o primeiro estudo que demonstra a eficiente ação microbicida intracelular de MCs murinos contra Aggregatibacter actinomycetemcomitans, com produção e liberação de substâncias potencialmente bactericidas, e de forma mais eficaz que os macrófagos...

Mast cells (MCs) are present in both normal and inflamed periodontal tissues, in varying amounts and locations. Recently, MCs contribution in eliminating bacteria and its effectiveness, through its intracellular microbicidal activity, have been increasingly recognized. Thus, this study aimed to investigate the intracellular microbicide capacity of MCs, and compare it with the microbicide capacity of murine peritoneal macrophages (MPs), considered professional phagocytes, by counting the colony forming units. Both cell types were challenged in vitro with periodontopathogen Aggregatibacter actinomycetemcomitans (ATCC 29523) by 3, 5, 10 and 24 hours. Additionally, the production and release of microbicidal agents, nitric oxide (NO) and hydrogen peroxide (H2O2) were evaluated by means of colorimetric Griess method and by the degradation of fluorescent substrates, respectively. Statistical analysis was performed by ANOVA Factorial test followed by Tukey and Pearson's correlation test (p <0.05). Our results revealed that MCs are able to efficiently eliminate periodontopathogen, mainly after 10 hours of intracellular challenge. The microbicidal activity of both cell types, in 3 and 5 hours of challenge showed a lower percentage of viable colonies inside MPs, compared to MCs. Contradictorily, in 10 and 24 hours a lower percentage of intracellular colonies in MCs was observed in relation to MPs. Moreover, the production/release of NO and, in minor proportion, of H2O2 by MCs was in agreement with its microbicidal capacity. Therefore, this is the first report to describe the intracellular microicidal activity of murine MCs against Aggregatibacter actinomycetemcomitans, concerning production and release of potentially bactericidal substances, which is more effective than macrophages. These results suggest the importance of these cells in pathogenesis and defense mechanisms of biofilm-associated periodontal disease.

Amitriptyline, clomipramine, and maprotiline attenuate the inflammatory response by inhibiting neutrophil migration and mast cell degranulation

Objective: Despite the recognized anti-inflammatory potential of heterocyclic antidepressants, the mechanisms concerning their modulating effects are not completely known. Thus, we evaluated the anti-inflammatory effect of amitriptyline, clomipramine, and maprotiline and the possible modulating properties of these drugs on neutrophil migration and mast cell degranulation. Methods: The hind paw edema and air-pouch models of inflammation were used. Male Wistar rats were treated with saline, amitriptyline, clomipramine or maprotiline (10, 30, or 90 mg/kg, per os [p.o.]) 1 h before the injection of carrageenan (300 μg/0.1 mL/paw) or dextran (500 μg/0.1 mL/paw). Then, edema formation was measured hourly. Neutrophil migration to carrageenan (500 μg/pouch) and N-formyl-methionyl-leucyl-phenylalanine (fMLP) (10-6 M/mL/pouch) was also investigated in 6-day-old air-pouch cavities. Compound 48/80-induced mast cell degranulation was assessed in the mesenteric tissues of antidepressant-treated rats. Results: All tested antidepressants prevented both carrageenan- and dextran-induced edema. The anti-inflammatory effect of these drugs partially depends on the modulation of neutrophil migration, since they significantly counteracted the chemotactic response of both carrageenan and fMLP (p < 0.01). Furthermore, amitriptyline, clomipramine and maprotiline inhibited compound 48/80-induced mast cell degranulation (p < 0.001). Conclusions: These results suggest an important anti-inflammatory role of heterocyclic antidepressants, which is dependent on the modulation of neutrophil migration and mast cell stabilization. .

Estudo comparativo dos efeitos da dexametasona e do diclofenaco sódico sobre o processo reparativo de feridas induzidas no ventre lingual de ratos / Comparative study of the effects of dexamethasone and diclofenac sodium on the repair process of induced wounds in the ventral tongue of rats

A inflamação é uma resposta protetora para livrar o organismo da causa inicial da lesão celular e suas consequências, porem se excessiva e não modulada, pode provocar a destruição progressiva do tecido. Este estudo pretende contribuir para o esclarecimento da influência de dois anti-inflamatórios, a dexametasona e o diclofenaco sódico, sobre a fase inflamatória do processo reparativo tecidual, bem como sobre o número de mastócitos nas diferentes fases do reparo. Foram utilizadas 60 ratas Wistar, divididas em 3 grupos (1, 2 e 3), medicadas 30 minutos antes de uma intervenção cirúrgica (lesão de 3mm de diâmetro no ventre lingual), com injeção intramuscular de 0,235mg/kg de dexametasona; 4,45mg/kg de diclofenaco sódico ou solução salina estéril, respectivamente. Os 3 grupos foram subdivididos em a, b, c, d, de acordo com o tempo de sacrifício: 6, 24, 48 e 120 horas após a cirurgia. As lesões foram fotografadas logo no momento cirúrgico e no sacrifício e as fotos utilizadas para análise clínica do processo de reparo e morfometria. As línguas foram extirpadas e enviadas para processamento histológico, os cortes foram direcionados para coloração em hematoxilina-eosina e em Azul de Toluidina para evidenciação e contagem do número de mastócitos. As características do processo reparativo foram descritas por meio de avaliação qualitativa dos seguintes componentes: extensão de áreas necróticas; intensidade de edema intersticial; tipo e intensidade do infiltrado inflamatório; graus de reepitelização, tecido de granulação e neovascularização.

Os cortes corados em HE também tiveram seus campos digitalizados e analisados morfometricamente, para quantificação da reepitelização, mensurações do tecido de granulação, celularidade e edema. Os resultados da análise histológica semiquantitativa evidenciaram que o diclofenaco e a dexametasona acarretaram menor infiltrado inflamatório em relação ao controle na fase inflamatória do reparo, porém na fase produtiva a dexametasona exibiu menor intensidade de reepitelização e de neovascularização em relação aos demais grupos. Os resultados da análise histomorfométrica mostraram significativamente menor edema no grupo do diclofenaco em 6h (p=0,0041) e em 24h (p=0,0429), bem como menor porcentagem da celularidade em 6 horas no grupo da dexametasona (p<0,0001). O grupo diclofenaco ainda exibiu menor área de lesão em 120h do que os demais grupos (p=0,0060), indicando maior eficiência de reparo. Quanto à quantidade de mastócitos em 24, 48 e 120 horas, o grupo controle exibiu significativamente os maiores valores (p<0,0001). Com base nesses resultados, conclui-se que o grupo da dexametasona apresentou pior desempenho em relação à reparação; que o diclofenaco sódico apresentou um melhor efeito sobre o fechamento da ferida cirúrgica e redução mais intensa do infiltrado inflamatório, e que ambos provocam redução de mastócitos na área lesionada.

Inflammation is a protective response to rid the body of the initial cause of cell damage and its consequences, but when excessive and unmodulated, may cause progressive destruction of tissue. The aim of this study is to clarify the influence of two anti-inflammatory, diclofenac sodium and dexamethasone on the inflammatory phase of tissue repair process, as well as on the number of mast cells in different stages of repair. It was used 60 Wistar rats, divided into 3 groups (1, 2 and 3), medicated 30 minutes before surgery (lesion 3 mm in diameter in the ventral tongue), with intramuscular injection of 0.235 mg / kg dexamethasone, 4, 45mg/Kg of diclofenac sodium or sterile saline, respectively. The 3 groups were subdivided into a, b, c, d, according to the time of sacrifice, 6, 24, 48 and 120 hours after surgery. The lesions were photographed immediately at surgical time and at sacrifice, the photos were used for clinical analysis of the repair process and morphometry. The tongues were excised and sent for histological processing, the slices were directed for staining with hematoxylin-eosin and toluidine blue, for disclosure and count of the number of mast cells. The characteristics of the repair process were described through qualitative evaluation of the following components: extension of necrotic areas; intensity of interstitial edema, type and intensity of inflammatory infiltrate; degrees of reepithelialization, granulation tissue and neovascularization. Slices stained with HE also had their fields scanned and analyzed morphometrically to quantify reepithelialization, measurements of the granulation tissue, cellularity and edema.

The results of semiquantitative histological analysis showed that diclofenac and dexamethasone led to lower inflammatory infiltrate compared to control in the inflammatory phase of repair, although in the productive phase dexamethasone showed less intensity of reepithelialization and neovascularization compared to the other groups. The results of the histomorphometric analysis showed significantly less edema in the diclofenac group at 6h (p = 0.0041) and 24 (p = 0.0429), as well as a lower percentage of cellularity in 6 hours in the dexamethasone group (p <0.0001). The diclofenac group also exhibited lower lesion area at 120h than the other groups (p = 0.0060), indicating greater efficiency of repair. Regarding the quantity of mast cells 24, 48 and 120 hours, the control group exhibited significantly higher values (p <0.0001). Based on these results, we conclude that the dexamethasone group showed the worst performance in relation to repair; that diclofenac sodium showed a better effect on surgical wound closure and greater reduction of inflammatory infiltration, and that both cause a reduction of mast cells in the injured area.

Revisión acerca de la biología y las funciones inmunológicas de los mastocitos / Review of the biology and immunological functions of mast cells

Los mastocitos o células cebadas son células que se hallan ampliamente distribuidas en todos los tejidos, principalmente en la piel y en las superficies mucosas cerca de los vasos sanguíneos y linfáticos. Pueden ser activadas por diversos estímulos de origen inmunitario o no inmunitario, liberando un amplio espectro de mediadores que incluyen histamina, proteasas, citoquinas, factores de crecimiento y metabolitos del ácido araquidónico. Estas moléculas juegan un importante papel en numerosos procesos fisiológicos y patológicos. La función mejor conocida de los mastocitos es la defensa contra infestaciones parasitarias; sin embargo, son importantes en la defensa del huésped a través de su participación en la inmunidad innata y adaptativa. Median la respuesta inflamatoria, la remodelación de los tejidos y la angiogénesis. Intervienen en las reacciones de hipersensibilidad tipo I y tienen un papel contradictorio en la progresión tumoral. En esta revisión se analiza el origen, la distribución y las funciones de los mastocitos en condiciones fisiológicas y en distintas enfermedades humanas.

novel insight to the functional role of stathmin 1 in IgE-mediated activation of RBL-2H3 cells

IgE-mediated cell signaling, induced by cross-linking of high affinity receptor for IgE [FepsilonRI] in the presence of antigen [Ag], is a well known mechanism described for mast cell activation in allergy and hypersensitivity reactions, which induces a spectrum of cellular responses such as secretion and up-regulation of cell surface FepsilonRL Although for several years IgE binding to FepsilonRI was considered to be a passive sensitization process, the outcomes of several recent studies have revealed a variety of different cellular responses to IgE binding compared to IgE plus Antigen binding. The present study applied a functional proteomics-based approach to investigate mast cell signaling events and provided new insights to FcsRI-mediated cell signaling in RBL-2H3.1 cells, and may point to the activation of alternative signaling pathways in response to IgE or IgE plus Ag. Comparative analysis by 2-D PAGE of RBL cells activated with IgE plus Ag for three and four hours compared to non-activated cells was followed by mass spectrometric protein identification and provided evidence for the induction of Stathmin 1 [STMN1] gene expression in response to IgE plus Ag activation. Complementary SDS-PAGE analysis showed a distinct up-regulation of STMN1 induction in response to challenge with IgE plus Ag compared to sensitization with IgE only. Phosphoproteomics analysis gave evidence for significant increase at phosphorylation of STMN1 on ser16 after 1min, though a slight rise at 5 min, and on ser38 after 1 and 5min sensitization with IgE and a similar result was observed for 1min IgE plus Ag-activation. IgE plus Ag-activation was also found to induce the phosphorylation of ser38 to a greater extent than sensitization with IgE. In contrast, IgE alone was more effective than IgE plus Ag at inducing phosphorylation of ser 16. Collectively this study provides further insights into the role of Stathmin 1 in FepsilonRI-mediated activation of cells of mast cell lineage and might shed light on the diverse response of these cells to IgE or IgE plus Ag

Prostaglandin D2 and TH2 Inflammation in the Pathogenesis of Bronchial Asthma

Prostaglandin D2 (PGD2) is a major prostanoid, produced mainly by mast cells, in allergic diseases, including bronchial asthma. PGD2-induced vasodilatation and increased permeability are well-known classical effects that may be involved in allergic inflammation. Recently, novel functions of PGD2 have been identified. To date, D prostanoid receptor (DP) and chemoattractant receptor homologous molecule expressed on TH2 cells (CRTH2) have been shown to be major PGD2-related receptors. These two receptors have pivotal roles mediating allergic diseases by regulating the functions of various cell types, such as TH2 cells, eosinophils, basophils, mast cells, dendritic cells, and epithelial cells. This review will focus on the current understanding of the roles of PGD2 and its metabolites in TH2 inflammation and the pathogenesis of bronchial asthma.

Immunohistochemical evaluation of mast cells and angiogenesis in oral squamous cell carcinoma.

Objectives : Angiogenesis is a complex event mediated by angiogenic factors released from cancer cells and immune cells. It has been reported to be associated with progression, aggressiveness and metastases of various malignant tumors including oral squamous cell carcinoma (OSCC). Similarly, mast cells have also been reported to play a role in tumor progression and metastases by promoting angiogenesis. The present study aims at comparison of microvascular density (MVD) and mast cell density (MCD) in normal oral mucosa (NM) and among various grades of OSCC. Materials and Methods : MVD was assessed immunohistochemically using anti-Factor VIII related von Willebrand factor, and MCD using anti-mast cell tryptase in a study sample of 30 cases of OSCC and 10 cases of clinically normal oral mucosa. Results : The mast cells in normal oral mucosa and oral squamous cell carcinoma strongly expressed mast cell tryptase. The density of mast cells and micro vessels were significantly higher in OSCC compared to normal oral mucosa. The MCD and MVD were higher in moderately differentiated OSCC than in well differentiated OSCC ( P > 0.05) and normal oral mucosa ( P < 0.05). Pearson's correlation revealed a positive correlation between MCD and MVD ( r=0.33; P=0.077). Conclusion : These findings indicate that mast cells may play a role in up regulation of tumor angiogenesis in OSCC probably through mast cell tryptase.

Quantitative role of mast cells in odontogenic cystic enlargement

Aim: Mast cells have been hypothesized to play a significant role in pathogenesis of odontogenic cysts. The aim of this study was to evaluate mast cell distribution in cystic lining and the capsule to formulate a mechanism of cystic expansion. Methods: Ten formalin-fixed paraffin embedded tissue blocks each of OKC, dentigerous and radicular cysts were selected. Toluidine blue staining (1% in 1% NaCl solution) was done in 5µm thick sections and counting performed in 10 areas using an ocular grid. Areas counted were divided into 4 zones: intraepithelial, subepithelial, intermediate and deep zones (Group I, II, III and IV respectively). Statistical analysis: Mean ±S.D. was calculated in each group followed by paired ‘T’ test. Results: Mast cells had greatest concentration in subepithelial zone. ‘T’ test showed no significant differences between group I and II zones in OKC but a highly significant difference between groups I and II in dentigerous cyst. Radicular cysts showed a significant difference between groups II and III. Conclusion: Mast cell degranulation releases numerous hydrolytic enzymes that facilitate breakdown of capsular matrix increasing the hydrostatic pressure due to raised osmolality. Influx of tissue fluids results in their enlargement coupled with resorption at the bone-cyst interface.

Histamine and spontaneously released mast cell granules ffect the cell growth of human hepatocellular carcinoma cells

The role of mast cells in tumor growth is still controversial. In this study we analyzed the effects of both histamine and pre-formed mediators spontaneously released by mast cells on the growth of two human hepatocellular carcinoma cell lines, HA22T/VGH and HuH-6, with different characteristics of differentiation, biological behavior and genetic defects. We showed that total mast cell releasate, exocytosed granules (granule remnants) and histamine reduced cell viability and proliferation in HuH-6 cells. In contrast, in HA22T/VGH cells granule remnants and histamine induced a weak but significant increase in cell growth. We showed that both cell lines expressed histamine receptors H1 and H2 and that the selective H1 antagonist terfenadine reverted the histamine-induced inhibition of HuH-6 cell growth, whereas the selective H2 antagonist ranitidine inhibited the histamine-induced cell growth of HA22T/VGH cells. We demonstrated that histamine down-regulated the expression of beta-catenin, COX-2 and survivin in HuH-6 cells and that this was associated with caspase-3 activation and PARP cleavage. On the contrary, in HA22T/VGH cells expression of survivin and beta-catenin increased after treatment with granule remnants and histamine. Overall, our results suggest that mediators stored in mast cell granules and histamine may affect the growth of liver cancer cells. However, mast cells and histamine may play different roles depending on the tumor cell features. Finally, these data suggest that histamine and histamine receptor agonists/antagonists might be considered as "new therapeutic" drugs to inhibit liver tumor growth.

Mucosal mast cell responses in rats (Rattus norvegicus) experimentally infected with Centrocestus caninus.

Mucosal mast cell (MMC) responses and worm recovery rates in rats experimentally infected with Centrocestus caninus were investigated. Metacercariae of C. caninus, procured from goldfish, Carassius auratus, were orally administered to twenty-five male rats (300 metacercariae each rat). The infected rats were sacrificed on days 3, 7, 14, 21 and 28 post-infection (PI) along with the control rats. Worm recovery was performed from each part of small intestine. To investigate MMC, duodenal, jejunal and ileal paraffinized-tissue sections were processed and stained with 1% alcian blue and 0.5% safranin-O. The average worm recovery rates were 42.8, 37.7, 21.2, 12.5 and 3.7% on days 3, 7, 14, 21 and 28 PI, respectively. The majority of the worms (98.9%) were collected from the duodenum and jejunum. The MMC numbers in the infected rats were significantly higher than those of the controls (p<0.05). A peak level was observed on days 14 PI and the numbers gradually decreased thereafter. The results reveal that MMC plays an important role in the expulsion of C. caninus from the host intestine. A more precise description of the role the MMC plays in helminth expulsion is still needed to understand the mechanism of host defense against intestinal helminthic infection, along with other effector cells, such as goblet cells.

Nitric oxide: a major determinant of mast cell phenotype and function

Mast cells (MC) are important in the numerous physiological processes of homeostasis and disease. Most notably, MC are critical effectors in the development and exacerbation of allergic disorders. Nitric oxide (NO) is a diatomic radical produced by nitric oxide synthase (NOS), and has pluripotent cell signaling and cytotoxic properties. NO can influence many MC functions. Recent evidence shows the source of this NO can be from the mast cell itself. Governing the production of this endogenous NO, through alterations in the expression of tetrahydrobiopterin (BH4), a NOS cofactor, has stabilizing effects on MC degranulation. Furthermore, NO regulates the synthesis and secretion of de novo generated mediators, including leukotrienes and chemokines. These novel observations add to the growing body of knowledge surrounding the role of NO in the MC.

Eosinophil Inflammation of Nasal Polyp Tissue: Relationships with Matrix Metalloproteinases, Tissue Inhibitor of Metalloproteinase-1, and Transforming Growth Factor-beta1

Eosinophil and mast cell infiltrations are consistent findings in nasal polyp tissue. Previous studies have shown that matrix metalloproteinases (MMPs) may be involved in eosinophil infiltration in airway mucosa of asthmatic patients, and that transforming growth factor-beta1 (TGF-beta1) induces extracellular matrix deposition in nasal polyp tissue. The aim of this study was to evaluate the role of MMPs and tissue-inhibitor of metalloproteinase-1 (TIMP-1) in association with TGF-beta1, eosinophils and mast cell activation in nasal polyp tissue. Nasal polyp tissues from 20 patients who underwent polypectomies were collected and prepared into tissue homogenate. Eosinophil cationic protein (ECP) and tryptase levels were measured by CAP system (Pharmacia, Sweden). MMP-2, MMP-9, TIMP-1 and TGF-beta1 levels were measured by enzyme-liked immunosorbent assay. MMP-2 was the predominant form of MMPs, followed by MMP-9 and TIMP-1. There were significant correlations between ECP, and MMP-9, MMP-2, TGF-beta1 and tryptase, but not with TIMP-1. Significant correlations were noted between tryptase, and MMP-2, MMP-9, and TGF-beta1, but not with TIMP-1. Close correlations were noted between TGF-beta1, and MMP-9 and MMP-2, but not with TIMP-1. MMP-2, MMP-9, and TGF-beta1 may contribute to eosinophil and mast cell migrations into nasal polyp tissue.

The mast cell and trauma / 法医学杂志

Mast cell(MC) takes an important role in trauma and the process of wound healing, and the pathophysiology reaction has a relationship to the time since trauma, which is helpful to determine the post-trauma and postmortem interval, and to distinguish the wound shaped whether before or after death. In this paper, the role of MC and its chemic medium in the process of wound healing, scar shaping, postburns inflammatory response, healing of bone fracture, as well as the signification for forensic medicine and the progress of researching in this field were reviewed.

Telangiectasia macularis eruptiva perstans: una forma clínica de mastocitosis / Telangiectasia macularis eruptiva perstans: a clinical form of mastocytosis

Comunicamos 6 casos de telangiectasia macularis eruptiva perstans, forma de mastocitosis cutánea de rara observación en la casuística nacional e internacional. Exponemos el hallazgo inusual de compromiso facial, con la presencia de lesiones maculosas y telangiectásicas en dos de los pacientes, así como la ausencia de dermografismo y signo de Darier en todos los casos, hechos que motivaron la presentación de este trabajo. Se efectúa una revisión de las características de la mastocitosis y de distintas clasificaciones de la misma. Se destaca el valor relativo del aumento del número de mastocitos en el estudio histológico de esta entidad