Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Más filtros










Intervalo de año de publicación
1.
Int J Inflam ; 2022: 3298542, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35265317

RESUMEN

AIRmax and AIRmin mice strains were selected according to the intensity of their acute inflammatory responsiveness. Previous studies have shown that AIR mice differ in their resistance to chemically induced skin tumors and in the development of melanoma metastases, in addition to differences in neutrophil and NK cells activity. In the present work, we aimed to evaluate whether the difference of susceptibility to murine melanoma is associated with NK cytotoxic activity against Yac.1 cells and lymphocyte subsets. Mice were subcutaneously inoculated with B16F10 or S91 melanoma cells. After 7, 14, or 30 days, the animals were euthanized to analyze the number of lymphocyte subsets, cytotoxic activity, and number of cytokine-producing spleen cells. AIRmax mice presented a higher number of CD4+/CD25+ cells than that of AIRmin mice following inoculation of B16F10 cells, whereas inoculation of S91 cells reduced CD4+/CD25+ and increased TCD8+ cell subsets in the AIRmax mice. AIRmax mice had a higher number of interleukin (IL)-10- and IL-12-producing cells and a lower number of interferon-γ-producing cells than those of AIRmin mice at 30 days. The cytotoxic activity of nonadherent spleen cells was similar in both the AIR strains. These results suggest that melanoma cells can induce different responses in AIR mice, possibly owing to alterations in regulatory mechanisms, such as the action of CD4+/CD25+ regulatory T cells and IL-10, in AIRmax mice.

2.
Artículo en Inglés | MEDLINE | ID: mdl-28344593

RESUMEN

BACKGROUND: Agaricus brasiliensis is a medicinal mushroom with immunomodulatory and antitumor activities attributed to the ß-glucans presented in the polysaccharide fraction of its fruiting body. Since ß-glucans enhance cellular immunoresponsiveness, in this study we aimed to evaluate the effect of an acid-treated polysaccharide-rich fraction (ATF) of A. brasiliensis on the ability of human monocytes to adhere/phagocyte C. albicans yeast cells, their expression of pattern recognition receptors and their ability to produce cytokines. METHODS: Adhesion/phagocytosis of FITC-labeled C. albicans was evaluated by flow cytometry. Cells were incubated with specific fluorochrome-labeled antibodies for TLR2 and 4, ßGR and MR and also evaluated by flow cytometry. Monocytes were cultured with ATF, and culture supernatants were collected for analysis of in vitro cytokine production by ELISA (TNF-α, IL-1ß, IL-12 and IL-10). RESULTS: ATF significantly increased the adherence/phagocytosis of C. albicans by monocytes and this was associated with enhanced expression of TLR2 and TLR4, while no effect was observed on ßGR or MR. Moreover, expression of TLR4 and TLR2 was associated with higher levels of in vitro production of TNF-α and IL-1, respectively. Production of IL-10 was also increased by ATF treatment, but we found no association between its production and the expression of Toll-like receptors. CONCLUSION: Our results provided us with evidence that A. brasiliensis polysaccharides affect human monocytes probably through the modulation of Toll-like receptors.

3.
Artículo en Inglés | LILACS-Express | LILACS, VETINDEX | ID: biblio-1484708

RESUMEN

Abstract Background Agaricus brasiliensis is a medicinal mushroom with immunomodulatory and antitumor activities attributed to the -glucans presented in the polysaccharide fraction of its fruiting body. Since -glucans enhance cellular immunoresponsiveness, in this study we aimed to evaluate the effect of an acid-treated polysaccharide-rich fraction (ATF) of A. brasiliensis on the ability of human monocytes to adhere/phagocyte C. albicans yeast cells, their expression of pattern recognition receptors and their ability to produce cytokines. Methods Adhesion/phagocytosis of FITC-labeled C. albicans was evaluated by flow cytometry. Cells were incubated with specific fluorochrome-labeled antibodies for TLR2 and 4, GR and MR and also evaluated by flow cytometry. Monocytes were cultured with ATF, and culture supernatants were collected for analysis of in vitro cytokine production by ELISA (TNF-, IL-1, IL-12 and IL-10). Results ATF significantly increased the adherence/phagocytosis of C. albicans by monocytes and this was associated with enhanced expression of TLR2 and TLR4, while no effect was observed on GR or MR. Moreover, expression of TLR4 and TLR2 was associated with higher levels of in vitro production of TNF- and IL-1, respectively. Production of IL-10 was also increased by ATF treatment, but we found no association between its production and the expression of Toll-like receptors. Conclusion Our results provided us with evidence that A. brasiliensis polysaccharides affect human monocytes probably through the modulation of Toll-like receptors.

4.
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-954846

RESUMEN

Agaricus brasiliensis é um cogumelo medicinal com atividades imunomoduladoras e antitumorais atribuídas aos ß-glucanos presentes na fração polissacarídica de seu corpo de frutificação. Uma vez que os ß-glucanos aumentam a imunorresponsividade celular, neste estudo objetivamos avaliar o efeito de uma fração rica em polissacarídeos tratados com ácido (ATF) de A. brasiliensis sobre a capacidade de monócitos humanos de aderir / fagocitar células de levedura C. albicans . expressão de receptores de reconhecimento de padrões e sua capacidade de produzir citocinas. Métodos: A adesão / fagocitose de C. albicans marcada com FITC foi avaliada por citometria de fluxo. As células foram incubadas com anticorpos marcados com fluorocromo específicos para TLR2 e 4, ßGR e MR e também avaliadas por citometria de fluxo. Os monócitos foram cultivados com ATF, e os sobrenadantes da cultura foram coletados para análise da produção de citocinas in vitro por ELISA (TNF-α, IL-1ß, IL-12 e IL-10). Resultados: ATF aumentou significativamente a aderência / fagocitose de C. albicans por monócitos e isso foi associado com expressão aumentada de TLR2 e TLR4, enquanto nenhum efeito foi observado em ßGR ou MR. Além disso, a expressão de TLR4 e TLR2 foi associada a níveis mais elevados de produção in vitro de TNF-α e IL-1, respectivamente. A produção de IL-10 também foi aumentada pelo tratamento com ATF, mas não encontramos associação entre sua produção e a expressão de receptores Toll-like. Conclusão: Nossos resultados nos forneceram evidências de que polissacarídeos de A. brasiliensis afetam monócitos humanos provavelmente através da modulação de receptores Toll-like.(AU)


Asunto(s)
Polisacáridos , Técnicas In Vitro , Agaricus , Candida albicans , Citocinas , Receptores Toll-Like
5.
Environ Toxicol Pharmacol ; 31(3): 387-96, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21787709

RESUMEN

Diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] is a substitute urea herbicide widely used on agricultural crops with potential mutagenic, teratogenic, reproductive and carcinogenic effects. Nonetheless, its toxic potential on the immune system needs a detailed assessment. Thus, in order to evaluate the adverse effect of this herbicide on lymphohematopoietic organs and macrophage activity, male Wistar rats were orally treated with Diuron at 125, 1250 and 2500 ppm for 14, 28 or 90 days. General signs of toxicity were observed in Diuron-treated groups (1250 and 2500 ppm), including reduced food intake and body weight gain, as well as higher relative weights for spleen, kidneys and liver (28 and 90-day toxicity studies) and elevated serum levels of ALT, albumin, total protein, creatinine and urea (28-day toxicity study). Diuron exposure caused a severe depletion of splenic white pulp compartments and cellularity, followed by a decreased number of CD4(+) T lymphocytes, increased extramedullary hematopoiesis and deposition of hemosiderin in red pulp. Despite alteration in macrophage spreading, the macrophagic activity was not significantly affected by the herbicide. Under these experimental conditions, the results suggest that Diuron exerts systemic and target-organ toxicity, mainly at higher concentration.


Asunto(s)
Diurona/toxicidad , Herbicidas/toxicidad , Animales , Peso Corporal/efectos de los fármacos , Médula Ósea/patología , Ingestión de Líquidos/efectos de los fármacos , Ingestión de Alimentos/efectos de los fármacos , Sistema Hematopoyético/efectos de los fármacos , Peróxido de Hidrógeno/metabolismo , Sistema Inmunológico/efectos de los fármacos , Pruebas de Función Hepática , Subgrupos Linfocitarios/efectos de los fármacos , Macrófagos/efectos de los fármacos , Masculino , Óxido Nítrico/metabolismo , Tamaño de los Órganos/efectos de los fármacos , Especificidad de Órganos , Oxidantes/metabolismo , Fagocitosis/efectos de los fármacos , Ratas , Ratas Wistar , Bazo/citología , Bazo/efectos de los fármacos , Bazo/inmunología
7.
Cell Immunol ; 256(1-2): 27-38, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19243740

RESUMEN

Subcutaneous Ehrlich tumor-bearing mice were treated with in situ inoculation of a beta-glucan-rich extract of Agaricus brasiliensis (ATF), which reduced tumor growth. Histopathological analysis showed that the tumor masses of control mice (Ehr) presented giant tumor cells and many mitotic figures whereas the tumor tissue obtained from ATF-treated animals (Ehr-ATF) presented a lower frequency of both mitotic and giant cells, associated with a higher frequency of apoptotic cells than Ehr. Analysis of the lymphoproliferative activity of spleen cells showed that the treatment had a suppressive rather than a stimulatory effect. Spleen cells of the Ehr group produced higher in vitro levels of IL-10 than normal controls and this occurrence was partially avoided by treatment with ATF. Analysis of cytokine production by tumor-infiltrating cells (ELISpot) showed that ATF induced a higher number of IFN-gamma-producing cells at 7 and 14days as well as reduction of IL-10-secreting cells at the latter time. Confocal microscopy analysis showed higher intensity of labeling of CD4+ and Mac-3+ cells in ATF-treated mice. Analysis of in situ expression of angiogenic growth factors showed a slight decrease of FGF-2 mRNA in Ehr-ATF animals (7th day) but not of VEGF-A or TGF-beta expression. This fraction could not directly lyse either lymphocytes or tumor cells and we speculate that antitumor effect of ATF could be due to induction of a selective migration of immunocompetent cells from the spleen to the tumor site and to the switch of cytokine production.


Asunto(s)
Agaricus/química , Carcinoma de Ehrlich/tratamiento farmacológico , Carcinoma de Ehrlich/inmunología , Interleucina-10/biosíntesis , Polisacáridos/farmacología , Proteínas Angiogénicas/genética , Animales , Carcinoma de Ehrlich/genética , Carcinoma de Ehrlich/patología , Citocinas/biosíntesis , Técnicas In Vitro , Interferón gamma/biosíntesis , Activación de Linfocitos/efectos de los fármacos , Linfocitos Infiltrantes de Tumor/efectos de los fármacos , Linfocitos Infiltrantes de Tumor/patología , Espectroscopía de Resonancia Magnética , Masculino , Ratones , Ratones Endogámicos BALB C , Estructura Molecular , Polisacáridos/química , Polisacáridos/aislamiento & purificación , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN Neoplásico/genética , ARN Neoplásico/metabolismo
8.
Mem Inst Oswaldo Cruz ; 103(3): 244-50, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18545860

RESUMEN

A polysaccharide-rich fraction (ATF) of medicinal mushroom Agaricus brasiliensis was evaluated on the candidacidal activity, H2O2 and nitric oxide (NO) production, and expression of mannose receptors by murine peritoneal macrophages. Mice received three intraperitoneal (i.p.) injections of ATF and after 48 h their peritoneal resident macrophages were assayed against Candida albicans yeast forms. The treatment increased fungicidal activity and it was associated with higher levels of H2O2, whereas NO production was not affected. We also found that the treatment enhances mannose receptor expression by peritoneal macrophages, which are involved in the attachment and phagocytosis of non-opsonized microorganisms. Treatment of animals with ATF was able to enhance the clearance of C. albicans during the first 6 h after the experimental i.p. infection. Our results suggest that this extract can increase host resistance against some infectious agents through the stimulation of microbicidal activity of macrophages.


Asunto(s)
Agaricus/química , Candida albicans/inmunología , Macrófagos Peritoneales/inmunología , Polisacáridos/farmacología , Animales , Candida albicans/efectos de los fármacos , Peróxido de Hidrógeno/inmunología , Lectinas Tipo C/inmunología , Macrófagos Peritoneales/efectos de los fármacos , Macrófagos Peritoneales/microbiología , Masculino , Receptor de Manosa , Lectinas de Unión a Manosa/inmunología , Ratones , Ratones Endogámicos BALB C , Óxido Nítrico/biosíntesis , Fagocitosis/efectos de los fármacos , Polisacáridos/aislamiento & purificación , Receptores de Superficie Celular/inmunología
9.
Mem. Inst. Oswaldo Cruz ; 103(3): 244-250, May 2008. ilus, graf
Artículo en Inglés | LILACS | ID: lil-485211

RESUMEN

A polysaccharide-rich fraction (ATF) of medicinal mushroom Agaricus brasiliensis was evaluated on the candidacidal activity, H2O2 and nitric oxide (NO) production, and expression of mannose receptors by murine peritoneal macrophages. Mice received three intraperitoneal (i.p.) injections of ATF and after 48 h their peritoneal resident macrophages were assayed against Candida albicans yeast forms. The treatment increased fungicidal activity and it was associated with higher levels of H2O2, whereas NO production was not affected. We also found that the treatment enhances mannose receptor expression by peritoneal macrophages, which are involved in the attachment and phagocytosis of non-opsonized microorganisms. Treatment of animals with ATF was able to enhance the clearance of C. albicans during the first 6 h after the experimental i.p. infection. Our results suggest that this extract can increase host resistance against some infectious agents through the stimulation of microbicidal activity of macrophages.


Asunto(s)
Animales , Masculino , Ratones , Agaricus/química , Candida albicans/inmunología , Macrófagos Peritoneales/inmunología , Polisacáridos/farmacología , Candida albicans/efectos de los fármacos , Peróxido de Hidrógeno/inmunología , Lectinas Tipo C/inmunología , Ratones Endogámicos BALB C , Macrófagos Peritoneales/efectos de los fármacos , Macrófagos Peritoneales/microbiología , Lectinas de Unión a Manosa/inmunología , Óxido Nítrico/biosíntesis , Fagocitosis/efectos de los fármacos , Polisacáridos/aislamiento & purificación , Receptores de Superficie Celular/inmunología
10.
Rev. Salusvita (Impr.) ; 19(2): 73-100, jan.-jul. 2000. tab, graf
Artículo en Portugués, Inglés | LILACS | ID: lil-284536

RESUMEN

Desenvolveu-se um método analítico para a extraçäo e determinaçäo de cocaína em amostras de urina. O método permite a injeçäo direta da amostra de urina em uma coluna cromatográfica ISRP-C8 (100mm x 4,6mm DI), empregando uma fase móvel composta por uma soluçäo de fosfato dibásico de sódio 0,05mol.L (pH 8,0) e acetonitrila 70:30 (v/v)


Asunto(s)
Muestreo , Cocaína Crack , Cocaína/orina , Cromatografía Líquida de Alta Presión
11.
Rev. Salusvita (Impr.) ; 18(2): 35-42, 1999. ilus, tab, graf
Artículo en Portugués | LILACS | ID: lil-273960

RESUMEN

Desenvolveu-se um método analítico para a extração e determinação das concentrações de cafeína em amostras de urina por cromatografia líquida de alta performance. O método envolve a injeção direta da amostra de urina em uma coluna cromatográfica ISRP (150mm X 4,6mm DI) empregando uma fase móvel composta por uma solução de fosfato dibásico de sódio 0,05 umol. L -1 (pH 8,0) e acetonitrila (90:10 v/v). As recuperações de cafeína presentes em amostras de urina fortificadas forma maiores que 98,40 mais ou menos 0,90 por cento com um desvio padrão relativo de 0,48 por cento. O limite de detecção para a determinação de cafeína foi de 0,1 mg.u L-1. O range de linearidade do detector foi determinado entre a s concentrações 0,1 a 18,0 ug.mL-1 para a cafeína.


Asunto(s)
Cafeína/orina , Cromatografía Líquida de Alta Presión/métodos , Inyecciones , Temperatura , Estimulantes del Sistema Nervioso Central , Cafeína/análisis
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...