49 research outputs found

    Bay 41-2272 activates host defence against local and disseminated candida albicans infections

    Get PDF
    In our previous study, we have found that 5-cyclopropyl-2-[1-(2-fluoro-benzyl)-1H-pyrazolo[3,4-b]pyridine-3-yl]-pyrimidin-4-ylamine (BAY 41-2272), a guanylate cyclase agonist, activates human monocytes and the THP-1 cell line to produce the superoxide anion, increasing in vitro microbicidal activity, suggesting that this drug can be used to modulate immune functioning in primary immunodeficiency patients. In the present work, we investigated the potential of the in vivo administration of BAY 41-2272 for the treatment of Candida albicans and Staphylococcus aureus infections introduced via intraperitoneal and subcutaneous inoculation. We found that intraperitoneal treatment with BAY 41-2272 markedly increased macrophage-dependent cell influx to the peritoneum in addition to macrophage functions, such as spreading, zymosan particle phagocytosis and nitric oxide and phorbol myristate acetate-stimulated hydrogen peroxide production. Treatment with BAY 41-2272 was highly effective in reducing the death rate due to intraperitoneal inoculation of C. albicans, but not S. aureus. However, we found that in vitro stimulation of peritoneal macrophages with BAY 41-2272 markedly increased microbicidal activities against both pathogens. Our results show that the prevention of death by the treatment of C. albicans-infected mice with BAY 41-2272 might occur primarily by the modulation of the host immune response through macrophage activation.In our previous study, we have found that 5-cyclopropyl-2-[1-(2-fluoro-benzyl)-1H-pyrazolo[3,4-b]pyridine-3-yl]-pyrimidin-4-ylamine (BAY 41-2272), a guanylate cyclase agonist, activates human monocytes and the THP-1 cell line to produce the superoxide anion, increasing in vitro microbicidal activity, suggesting that this drug can be used to modulate immune functioning in primary immunodeficiency patients. In the present work, we investigated the potential of the in vivo administration of BAY 41-2272 for the treatment of Candida albicans and Staphylococcus aureus infections introduced via intraperitoneal and subcutaneous inoculation. We found that intraperitoneal treatment with BAY 41-2272 markedly increased macrophage-dependent cell influx to the peritoneum in addition to macrophage functions, such as spreading, zymosan particle phagocytosis and nitric oxide and phorbol myristate acetate-stimulated hydrogen peroxide production. Treatment with BAY 41-2272 was highly effective in reducing the death rate due to intraperitoneal inoculation of C. albicans, but not S. aureus. However, we found that in vitro stimulation of peritoneal macrophages with BAY 41-2272 markedly increased microbicidal activities against both pathogens. Our results show that the prevention of death by the treatment of C. albicans-infected mice with BAY 41-2272 might occur primarily by the modulation of the host immune response through macrophage activation1101758

    Protective activity of the antilipopolysaccharide antibodies from human cord serum

    Get PDF
    We evaluated the ability of human maternal and cord serum antibodies to protect mice challenged with live Escherichia coli serotype O6:K2ac (E. coli O6). Mice received paired maternal or cord serum pools before a challenge with E. coli O6 to evaluate the mortality rate. All the pools were able to protect the animals challenged with bacteria except the test group from paired maternal and cord sera from preterm neonates containing less than 1.0 mg L-1 immunoglobulin G antibody levels. in liver, spleen and mesenteric lymph nodes from the control group (phosphate-buffered saline), more than 10(2) CFU mL(-1) bacteria were found at 30 min and more than 10(5) CFU mL(-1) after 120 min. the test group showed lower bacterial counts in the organs, and no bacteria in the mesenteric lymph nodes during the evaluated period. Tumor necrosis factor alpha and interleukin 6 were undetectable in serum from animals pretreated with paired maternal and cord serum pools from full-term neonates and pools from preterm neonates containing high antibody and avidity levels. Our findings suggest that placental transfer of antilipopolysaccharide O6 immunoglobulin G antibodies to neonates has a high capacity to prevent lethal infection with E. coli O6 in a mouse protection model and that the degree of protection is determined by the concentration and avidity of these IgG antibodies.Univ São Paulo, Inst Ciencias Biomed, Lab Imunol Mucosas, Dept Immunol, BR-05508900 São Paulo, BrazilUniv São Paulo, Dept Parasitol, Inst Biomed Sci, BR-05508900 São Paulo, BrazilUniv São Paulo, Sch Med, Dept Pediat, BR-05508900 São Paulo, BrazilUniv Fed Ceara, Dept Clin Anal & Toxicol, São Paulo, BrazilWeb of Scienc

    The Role of M. leprae

    Get PDF
    Experimental autoimmune uveitis (EAU) is a well established model for immune-mediated organ-specific disease. Our group has recently shown that the M. leprae Hsp65 aggravated the uveitis in mice; in the present study, we evaluated the action of M. leprae  K409A mutant protein and the synthetic peptides Leader pep and K409A pep (covering amino acids residues 352–371 of WT and K409A proteins of M. leprae Hsp65, resp.) on the pathogenesis of EAU. Mice received the 161–180 IRBP peptide and B. pertussis toxin followed by the intraperitoneal inoculation of K409A protein or the Leader pep or K409A pep. The Leader pep aggravated the disease, but mice receiving the K409A pep did not develop the disease and presented an increase in IL-10 levels by spleen cells and a decrease in the percentage of CD4+ IFN-γ+ T cells. Moreover, animals receiving the Leader pep presented the highest scores of the disease associated with increase percentage of CD4+ IFN-γ+ T cells. These results would contribute to understanding of the pathogenesis of EAU and support the concept that immune responses to Hsp are of potential importance in exacerbating, perpetuating, or even controlling organ-restricted autoimmune diseases, and it is discussed the irreversibility of autoimmune syndromes

    Early Exposure to Respiratory Allergens by Placental Transfer and Breastfeeding.

    No full text
    The relationship between allergen exposure and the onset of or protection from allergic diseases remains unclear. Many factors could be related to immunological responses, such as the age when the exposure occurs, type of allergen, timing, dose, and allergen route. In this study, we investigated whether exposure to respiratory allergens could occur in pregnancy or early life. In particular, we assessed whether Der p 1 and Blo t 5, as well as specific antibodies against these allergens, could be detected in 90 paired cord blood and colostrum samples. Der p 1 was detected in 58.6% of colostrum and 29% of cord blood samples, whereas Blot 5 was positive in 41.3% and 9.6% of the samples, respectively. Similar to specific IgA, which could be detected in all samples for both mites, specific IgG was found in a high number of colostrum samples, 93.5% and 94.8% for Dp and Bt, respectively. Although allergens were not detected in all cord blood samples, a high percentage of them (≥95%) were positive for specific IgM to both mites in cord blood samples, suggesting that neonates can be exposed and sensitized to airborne allergens during pregnancy. Many studies have attempted to correlate allergen exposure or its prevention in early infancy with the onset of or protection from allergic diseases. However, conflicting and inconsistent data do not show a clear correlation with or suggest a way to prevent allergen sensitization. Nevertheless, these unconvincing results could be better understood if the relationship with many aspects of allergen exposure after pregnancy could be clarified. Thus, it is necessary to address basic issues related to allergen exposure, including the development of reproducible, standardized and reliable methods, and to determine how and where the exposure occurs

    Evaluación de la vacuna neumocócica 7-valente en la respuesta humoral de niños con SIDA

    Get PDF
    OBJETIVO: A doença pneumocócica invasiva é importante causa de morbi-mortalidade em crianças infectadas pelo HIV. O objetivo do estudo foi avaliar quantitativamente a resposta com anticorpos aos sete sorotipos pneumocócicos da vacina em um grupo de crianças infectadas pelo HIV. MÉTODOS: Estudo realizado com 40 crianças infectadas pelo HIV, com idade entre 2 e 9 anos, em seguimento em ambulatório especializado no município de São Paulo, em 2002-2003. A dosagem de anticorpos IgG contra os polissacarídeos da cápsula pneumocócica foi realizada por meio de ensaio imunoenzimático (ELISA). Os anticorpos foram dosados imediatamente antes e um mês após a aplicação da segunda dose da vacina. Utilizaram-se dois critérios para avaliar a resposta à vacina: títulos de anticorpos >1,3 µg/mL na sorologia pós-imunização e aumento >4 vezes nos títulos da sorologia pós em relação à pré-imunização. RESULTADOS: Para o primeiro critério (>1,3 µg/mL), 26 (65%) crianças obtiveram resposta sorológica à vacina, 12 (30%) delas apresentaram títulos de IgG pós-imunização em níveis de pelo menos 1,3 µg/mL para todos os sorotipos. Para o segundo critério (incremento >4 vezes nos títulos para quatro sorotipos ou mais), obteve-se resposta sorológica para 15 (37,5%) crianças. CONCLUSÕES: A resposta à vacina foi considerada satisfatória, com aumento estatisticamente significante dos títulos geométricos médios pós-vacinais em relação aos pré-vacinais para todos os sorotipos estudados.OBJECTIVE: Invasive pneumococcal disease is a major cause of death in HIV-infected children. The objective of the study was to assess the quantitative antibody response to the seven pneumococcal serotypes of heptavalent pneumococcal conjugate vaccine in a group of HIV-infected children. METHODS: Study comprising 40 HIV-infected children aged between 2 and 9 years followed up in a specialized outpatient clinic in São Paulo, Brazil, between 2002 and 2003. Enzyme immunoassay (ELISA) was used to measure IgG antibody titers against pneumococcus capsule. Antibodies were measured immediately before and 1 month after the second dose of the vaccine. Two response criteria were used: IgG titers >1.3 µg/mL in the post-immunization serology and an increase of at least 4-fold in post- compared to pre-immunization serology. RESULTS: For the first criterion (>1.3 µg/mL), 26 (65%) children had serological response to the vaccine, 12 (30%) showed post-immunization IgG titers of at least 1.3 µg/mL for all seven serotypes studied. For the second criterion studied (>4-fold increase in post- compared to pre-immunization titers for four serotypes or more), serological response was seen in 15 (37.5%) children. CONCLUSIONS: Overall response to the heptavalent pneumococcal conjugate vaccine was adequate, showing a statistically significant increase in the post-immunization geometric mean titers for the seven serotypes studied.OBJETIVO: La enfermedad neumocócica es una importante causa de morbi-mortalidad en niños infectados por HIV. El objetivo del estudio fue evaluar cuantitativamente la respuesta de anticuerpos para los siete serotipos neumocócicos de la vacuna en un grupo de niños infectados por HIV. MÉTODOS: El estudio fue realizado con 40 niños infectados por HIV, con edades entre 2 y 9 años, con seguimiento en ambulatorio especializado en el municipio de Sao Paulo (Sureste de Brasil), en 2002-2003. La dosis de anticuerpos IgG contra los polisacáridos de la cápsula neumocócica fue realizada por medio de ensayo inmuno enzimático (ELISA). Los anticuerpos fueron dosificados inmediatamente antes y un mes después de la aplicación de la segunda dosis de la vacuna. Se utilizaron dos criterios para evaluar la respuesta a la vacuna: títulos de anticuerpos ? 1,3 ?g/mL en la serología post-inmunización y aumento ?4 veces en los títulos de la serología post-inmunización con relación a la pre-inmunización. RESULTADOS: Para el primer criterio (?1,3 ?g/mL), 26 (65%) niños obtuvieron respuesta serológica con la vacuna, 12 (30%) de ellas presentaron títulos de IgG post-inmunización en niveles de por lo menos 1,3 ?g/mL para todos los serotipos. Para el segundo criterio (incremento >4 veces en los títulos para cuatro serotipos o mas), se obtuvo respuesta serológica en 15 (37,5%) niños. CONCLUSIONES: La respuesta frente a la vacuna fue considerada satisfactoria, con aumento estadísticamente significativo de los títulos geométricos promedios post-vacunales con relación a los pre-vacunales para todos los serotipos estudiados

    4-Fluoro-2-methoxyphenol, an apocynin analog with enhanced inhibitory effect on leukocyte oxidant production and phagocytosis

    Get PDF
    Apocynin, a methoxy-substituted catechol (4-hydroxy-3-methoxyacetophenone), originally extracted from the roots of Picrorhiza kurroa, has been extensively used as a non-toxic inhibitor of the multienzymatic complex NADPH oxidase. We discovered that the analogous methoxy-substituted catechol, 4-Fluoro-2-methoxyphenol (F-apocynin), in which the acetyl group present in apocynin was changed to a fluorine atom, was significantly more potent as an inhibitor of NADPH oxidase activity, myeloperoxidase (MPO) chlorinating activity and phagocytosis of microorganisms by neutrophils; it was also as potent as apocynin in inhibiting tumor necrosis factor-alpha (TNF alpha) release by peripheral blood mononuclear cells. We attribute the increased potency of F-apocynin to its increased lipophilicity, which could facilitate the passage of the drug through the cell membrane. The inhibition of MPO chlorination activity, phagocytosis and TNF alpha release shows that apocynin and F-apocynin actions are not restricted to reactive oxygen species inhibition, but further studies are needed to clarify if these mechanisms are related. Like apocynin, F-apocynin did not show cell toxicity, and is a strong candidate for use in the treatment of inflammatory diseases. (C) 2011 Elsevier B.V. All rights reserved.Sao Paulo Research Foundation (FAPESP)[2008/53458-6]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)National Council for Scientific and Technological Development (CNPq

    Treatment of Gestational Diabetes Mellitus and Offspring Early Childhood Growth

    No full text
    Background: Gestational diabetes mellitus (GDM) is associated with fetal overgrowth, and certain treatments are associated with an increased risk of macrosomia. However, there are limited data about the long-term effect of GDM treatment on childhood growth. Methods: Cohort study of 816 women with GDM and their offspring delivered between 2009 and 2012. Childhood height and weight through age 3 were collected from the medical record and z-scores and body mass index (BMI) were calculated. We assessed the association between GDM treatment and childhood growth using linear mixed modeling. Results: Treatment was divided into medical nutritional therapy (MNT) (n = 293), glyburide (n = 421), and insulin (n = 102). At delivery, birthweight, z-score, and BMI were higher in the offspring of women treated with either glyburide or insulin compared to MNT. However, weight, z-score, and BMI were similar among all offspring at 6 months and 1, 2, and 3 years of age. After controlling for covariates, there were differences in the weight z-score (P = 0.01) over the 3-year period by treatment group, but no differences in weight (P = 0.06) or change in BMI (P = 0.28). Pairwise comparisons indicated that insulin was associated with more weight gain compared with MNT (0.69 kg; 95% CI, 0.10-1.28; P = 0.02) and glyburide was associated with a trend toward lower weight z-score compared with MNT (-0.24; 95% CI, -0.47 to 0.003; P = 0.05). Conclusion: Despite growth differences detected at birth, we observed no meaningful differences in childhood growth from 6 months to 3 years among treatment groups, including in the offspring of women with GDM treated with glyburide
    corecore