Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 26
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Cell Rep Med ; 4(8): 101130, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37490914

RESUMO

Signal regulatory protein (SIRPα) is an immune inhibitory receptor expressed by myeloid cells to inhibit immune cell phagocytosis, migration, and activation. Despite the progress of SIRPα and CD47 antagonist antibodies to promote anti-cancer immunity, it is not yet known whether SIRPα receptor agonism could restrain excessive autoimmune tissue inflammation. Here, we report that neutrophil- and monocyte-associated genes including SIRPA are increased in inflamed tissue biopsies from patients with rheumatoid arthritis and inflammatory bowel diseases, and elevated SIRPA is associated with treatment-refractory ulcerative colitis. We next identify an agonistic anti-SIRPα antibody that exhibits potent anti-inflammatory effects in reducing neutrophil and monocyte chemotaxis and tissue infiltration. In preclinical models of arthritis and colitis, anti-SIRPα agonistic antibody ameliorates autoimmune joint inflammation and inflammatory colitis by reducing neutrophils and monocytes in tissues. Our work provides a proof of concept for SIRPα receptor agonism for suppressing excessive innate immune activation and chronic inflammatory disease treatment.


Assuntos
Colite , Neoplasias , Humanos , Fagocitose , Neoplasias/tratamento farmacológico , Neutrófilos/metabolismo , Inflamação/patologia , Colite/metabolismo
2.
Proc Natl Acad Sci U S A ; 117(48): 30628-30638, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33199625

RESUMO

Macrophages respond to microbial ligands and various noxious cues by initiating an inflammatory response aimed at eliminating the original pathogenic insult. Transition of macrophages from a proinflammatory state to a reparative state, however, is vital for resolution of inflammation and return to homeostasis. The molecular players governing this transition remain poorly defined. Here, we find that the reparative macrophage transition is dictated by B-cell adapter for PI3K (BCAP). Mice harboring a macrophage-specific deletion of BCAP fail to recover from and succumb to dextran sulfate sodium-induced colitis due to prolonged intestinal inflammation and impaired tissue repair. Following microbial stimulation, gene expression in WT macrophages switches from an early inflammatory signature to a late reparative signature, a process that is hampered in BCAP-deficient macrophages. We find that absence of BCAP hinders inactivation of FOXO1 and GSK3ß, which contributes to their enhanced inflammatory state. BCAP deficiency also results in defective aerobic glycolysis and reduced lactate production. This translates into reduced histone lactylation and decreased expression of reparative macrophage genes. Thus, our results reveal BCAP to be a critical cell-intrinsic switch that regulates transition of inflammatory macrophages to reparative macrophages by imprinting epigenetic changes.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Histonas/metabolismo , Macrófagos/metabolismo , Transdução de Sinais , Receptores Toll-Like/metabolismo , Animais , Camundongos , Processamento de Proteína Pós-Traducional
3.
Cells ; 9(2)2020 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-32041253

RESUMO

Transforming Growth Factor ß (TGF-ß) is involved in fibrosis as well as the regulation of muscle mass, and contributes to the progressive pathology of muscle wasting disorders. However, little is known regarding the time-dependent signalling of TGF-ß in myoblasts and myotubes, as well as how TGF-ß affects collagen type I expression and the phenotypes of these cells. Here, we assessed effects of TGF-ß on gene expression in C2C12 myoblasts and myotubes after 1, 3, 9, 24 and 48 h treatment. In myoblasts, various myogenic genes were repressed after 9, 24 and 48 h, while in myotubes only a reduction in Myh3 expression was observed. In both myoblasts and myotubes, TGF-ß acutely induced the expression of a subset of genes involved in fibrosis, such as Ctgf and Fgf-2, which was subsequently followed by increased expression of Col1a1. Knockdown of Ctgf and Fgf-2 resulted in a lower Col1a1 expression level. Furthermore, the effects of TGF-ß on myogenic and fibrotic gene expression were more pronounced than those of myostatin, and knockdown of TGF-ß type I receptor Tgfbr1, but not receptor Acvr1b, resulted in a reduction in Ctgf and Col1a1 expression. These results indicate that, during muscle regeneration, TGF-ß induces fibrosis via Tgfbr1 by stimulating the autocrine signalling of Ctgf and Fgf-2.


Assuntos
Colágeno Tipo I/metabolismo , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Fator 2 de Crescimento de Fibroblastos/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Mioblastos/metabolismo , Fator de Crescimento Transformador beta/farmacologia , Animais , Diferenciação Celular/efeitos dos fármacos , Tamanho Celular/efeitos dos fármacos , Células Cultivadas , Fibrose , Regulação da Expressão Gênica/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Modelos Biológicos , Desenvolvimento Muscular/efeitos dos fármacos , Desenvolvimento Muscular/genética , Fibras Musculares Esqueléticas/efeitos dos fármacos , Mioblastos/efeitos dos fármacos , Miostatina/farmacologia , Receptor do Fator de Crescimento Transformador beta Tipo I/metabolismo , Fatores de Tempo
4.
J Exp Med ; 217(4)2020 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-31967646

RESUMO

Dendritic cells (DCs) are critical for the differentiation of pathogen-specific CD4 T cells. However, to what extent innate cues from DCs dictate transcriptional changes in T cells remains elusive. Here, we used DCs stimulated with specific pathogens to prime CD4 T cells in vitro and found that these T cells express unique transcriptional profiles dictated by the nature of the priming pathogen. More specifically, the transcriptome of in vitro C. rodentium-primed Th17 cells resembled that of Th17 cells primed following infection in vivo but was remarkably distinct from cytokine-polarized Th17 cells. We identified caspase-1 as a unique gene up-regulated only in pathogen-primed Th17 cells and discovered a critical role for T cell-intrinsic caspase-1, independent of inflammasome, in optimal priming of Th17 responses. T cells lacking caspase-1 failed to induce colitis or confer protection against C. rodentium infection due to suboptimal Th17 cell differentiation in vivo. This study underlines the importance of DC-mediated priming in identifying novel regulators of T cell differentiation.


Assuntos
Caspase 1/genética , Diferenciação Celular/genética , Células Th17/metabolismo , Células Th17/microbiologia , Transcrição Gênica/genética , Animais , Linhagem Celular Tumoral , Polaridade Celular , Citrobacter rodentium , Colite/genética , Colite/metabolismo , Citocinas/metabolismo , Células Dendríticas/metabolismo , Infecções por Enterobacteriaceae/metabolismo , Infecções por Enterobacteriaceae/microbiologia , Feminino , Técnicas de Inativação de Genes , Inflamassomos/metabolismo , Ativação Linfocitária/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transcriptoma
5.
Nat Immunol ; 21(1): 65-74, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31848486

RESUMO

The cytokine interleukin (IL)-1ß is a key mediator of antimicrobial immunity as well as autoimmune inflammation. Production of IL-1ß requires transcription by innate immune receptor signaling and maturational cleavage by inflammasomes. Whether this mechanism applies to IL-1ß production seen in T cell-driven autoimmune diseases remains unclear. Here, we describe an inflammasome-independent pathway of IL-1ß production that was triggered upon cognate interactions between effector CD4+ T cells and mononuclear phagocytes (MPs). The cytokine TNF produced by activated CD4+ T cells engaged its receptor TNFR on MPs, leading to pro-IL-1ß synthesis. Membrane-bound FasL, expressed by CD4+ T cells, activated death receptor Fas signaling in MPs, resulting in caspase-8-dependent pro-IL-1ß cleavage. The T cell-instructed IL-1ß resulted in systemic inflammation, whereas absence of TNFR or Fas signaling protected mice from CD4+ T cell-driven autoimmunity. The TNFR-Fas-caspase-8-dependent pathway provides a mechanistic explanation for IL-1ß production and its consequences in CD4+ T cell-driven autoimmune pathology.


Assuntos
Autoimunidade/imunologia , Linfócitos T CD4-Positivos/imunologia , Inflamação/patologia , Interleucina-1beta/metabolismo , Células Mieloides/metabolismo , Animais , Caspase 1/genética , Caspase 8/metabolismo , Células Cultivadas , Células Dendríticas/imunologia , Proteína Ligante Fas/metabolismo , Imunidade Inata/imunologia , Inflamassomos/imunologia , Inflamação/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mycobacterium tuberculosis/imunologia , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
6.
Life (Basel) ; 7(4)2017 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-29160840

RESUMO

We report the heterologous expression and molecular characterization of the first extremely halophilic alpha-glucosidase (EC 3.2.1.20) from the archaeon Haloquadratum walsbyi. A 2349 bp region (Hqrw_2071) from the Hqr. walsbyi C23 annotated genome was PCR-amplified and the resulting amplicon ligated into plasmid pET28b(+), expressed in E. coli Rosetta cells, and the resulting protein purified by Ni-NTA affinity chromatography. The recombinant protein showed an estimated molecular mass of 87 kDa, consistent with the expected value of the annotated protein, and an optimal activity for the hydrolysis of α-PNPG was detected at 40 °C, and at pH 6.0. Enzyme activity values were the highest in the presence of 3 M NaCl or 3-4 M KCl. However, specific activity values were two-fold higher in the presence of 3-4 M KCl when compared to NaCl suggesting a cytoplasmic localization. Phylogenetic analyses, with respect to other alpha-glucosidases from members of the class Halobacteria, showed that the Hqr. walsbyi MalH was most similar (up to 41%) to alpha-glucosidases and alpha-xylosidases of Halorubrum. Moreover, computational analyses for the detection of functional domains, active and catalytic sites, as well as 3D structural predictions revealed a close relationship with an E. coli YicI-like alpha-xylosidase of the GH31 family. However, the purified enzyme did not show alpha-xylosidase activity. This narrower substrate range indicates a discrepancy with annotations from different databases and the possibility of specific substrate adaptations of halophilic glucosidases due to high salinity. To our knowledge, this is the first report on the characterization of an alpha-glucosidase from the halophilic Archaea, which could serve as a new model to gain insights into carbon metabolism in this understudied microbial group.

7.
J Exp Med ; 214(11): 3279-3292, 2017 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-28951494

RESUMO

Patients with stimulator of interferon genes (STING)-associated vasculopathy with onset in infancy (SAVI) develop systemic inflammation characterized by vasculopathy, interstitial lung disease, ulcerative skin lesions, and premature death. Autosomal dominant mutations in STING are thought to trigger activation of IRF3 and subsequent up-regulation of interferon (IFN)-stimulated genes (ISGs) in patients with SAVI. We generated heterozygous STING N153S knock-in mice as a model of SAVI. These mice spontaneously developed inflammation within the lung, hypercytokinemia, T cell cytopenia, skin ulcerations, and premature death. Cytometry by time-of-flight (CyTOF) analysis revealed that the STING N153S mutation caused myeloid cell expansion, T cell cytopenia, and dysregulation of immune cell signaling. Unexpectedly, we observed only mild up-regulation of ISGs in STING N153S fibroblasts and splenocytes and STING N154S SAVI patient fibroblasts. STING N153S mice lacking IRF3 also developed lung disease, myeloid cell expansion, and T cell cytopenia. Thus, the SAVI-associated STING N153S mutation triggers IRF3-independent immune cell dysregulation and lung disease in mice.


Assuntos
Inflamação/metabolismo , Fator Regulador 3 de Interferon/metabolismo , Proteínas de Membrana/metabolismo , Doenças Vasculares/metabolismo , Animais , Células Cultivadas , Citocinas/metabolismo , Fibroblastos/metabolismo , Humanos , Inflamação/genética , Fator Regulador 3 de Interferon/genética , Pulmão/metabolismo , Pulmão/patologia , Proteínas de Membrana/genética , Camundongos Knockout , Camundongos Transgênicos , Mutação , Pele/metabolismo , Pele/patologia , Linfócitos T/metabolismo , Linfócitos T/patologia , Doenças Vasculares/genética
8.
Cell Rep ; 18(11): 2600-2607, 2017 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-28297665

RESUMO

TREX1 mutations are associated with several autoimmune and inflammatory diseases. The N-terminal DNase domain of TREX1 is important for preventing self-DNA from activating the interferon response. The C terminus of TREX1 is required for ER localization and regulation of oligosacchariyltransferase (OST) activity. Here, we show that during mitosis TREX1 is predominately phosphorylated at the C-terminal Serine-261 by Cyclin B/CDK1. TREX1 is dephosphorylated quickly at mitotic exit, likely by PP1/PP2-type serine/threonine phosphatase. Mitotic phosphorylation does not affect TREX1 DNase activity. Phosphomimetic mutations of mitotic phosphorylation sites in TREX1 disrupted the interaction with the OST subunit RPN1. RNA-seq analysis of Trex1-/- mouse embryonic fibroblasts expressing TREX1 wild-type or phosphor-mutants revealed a glycol-gene signature that is elevated when TREX1 mitotic phosphorylation sites are disrupted. Thus, the cell-cycle-dependent post-translation modification of TREX1 regulates its interaction with OST, which may have important implications for immune disease associated with the DNase-independent function of TREX1.


Assuntos
Exodesoxirribonucleases/química , Hexosiltransferases/metabolismo , Proteínas de Membrana/metabolismo , Mitose , Fosfoproteínas/química , Sequência de Aminoácidos , Animais , Proteína Quinase CDC2/metabolismo , Ciclina B/metabolismo , Desoxirribonucleases/metabolismo , Exodesoxirribonucleases/metabolismo , Glicóis/metabolismo , Células HeLa , Humanos , Camundongos , Fosfoproteínas/metabolismo , Fosforilação , Ligação Proteica , Células RAW 264.7 , Relação Estrutura-Atividade , Transcriptoma/genética
9.
J Nucl Med Technol ; 33(4): 234-7, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16322125

RESUMO

OBJECTIVE: Exogenous natural surfactant (ENS) labeled with 99mTc shows an elevated lung specificity allowing the acquisition of high-quality images for ventilation scintigraphy. METHODS: The methods for 99mTc-ENS quality control (physical properties, pH determination, radiochemical studies, and biologic studies) were evaluated and validated. RESULTS: The physical properties of the nonradioactive precursor and of the radiopharmaceutical were analyzed as general descriptors of the product. The pH of the radiopharmaceutical was determined by using pH test papers, a method described and validated in the United States Pharmacopeia. Chromatographic studies performed using the acetone/Whatman-1 paper system were validated as a method to evaluate the radiochemical purity of the 99mTc-ENS. Biodistribution studies on rats after intratracheal administration were validated as a method to estimate the radiopharmaceutical biodistribution in humans. CONCLUSION: The proposed method for 99mTc-ENS quality control studies and stability studies was evaluated and validated following international standards.


Assuntos
Marcação por Isótopo/métodos , Pulmão/metabolismo , Surfactantes Pulmonares/farmacocinética , Tecnécio/farmacocinética , Animais , Avaliação Pré-Clínica de Medicamentos/métodos , Avaliação Pré-Clínica de Medicamentos/normas , Marcação por Isótopo/normas , Pulmão/diagnóstico por imagem , Taxa de Depuração Metabólica , Especificidade de Órgãos , Surfactantes Pulmonares/análise , Surfactantes Pulmonares/normas , Controle de Qualidade , Cintilografia , Compostos Radiofarmacêuticos/análise , Compostos Radiofarmacêuticos/farmacocinética , Compostos Radiofarmacêuticos/normas , Ratos , Ratos Sprague-Dawley , Tecnécio/análise , Tecnécio/normas , Distribuição Tecidual
10.
Neuroimmunomodulation ; 12(2): 92-9, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15785111

RESUMO

OBJECTIVE: The aim of this work was to analyze beta-adrenergic receptor (betaAR) regulation of T-lymphocyte proliferation in mice according to different thyroid hormone statuses. METHODS: T cells from eu-, hypo- (by propylthiouracil treatment) and hyperthyroid (by thyroxine, T4 administration) mice were purified and specific radioligand binding assays were performed. The effects of the beta-agonist isoproterenol (ISO) on intracellular levels of cyclic AMP (cAMP) were determined. Mitogen-induced T-cell proliferation was measured by [(3)H]-thymidine incorporation. Finally, protein kinase C (PKC) activity in cytosol and membrane fractions were determined using radiolabelled enzymatic substrates. RESULTS: Adecrease or a non-significant increase in betaAR number was found on T lymphocytes from hypo- and hyperthyroid mice compared to euthyroid controls. ISO stimulation of cAMP levels was lower in hypothyroid and higher in hyperthyroid T lymphocytes compared to controls. T-selective mitogen-induced proliferation was increased in T4-treated animals, but decreased in hypothyroid mice. During the peak of proliferation, downregulation of betaAR was observed in all animals. However, a higher or a lower decrease was observed in hyper- and hypothyroid T cells, respectively. In parallel, a higher translocation of PKC activity was observed in hyperthyroid cells, and a lower one was found in hypothyroid lymphocytes with respect to controls. CONCLUSIONS: These results indicate that intracellular signals triggered by mitogen activation, namely PKC, would be related to differential betaAR downregulation in T lymphocytes depending on the thyroid hormone status, contributing to the distinct proliferative responses found in hypo- or hyperthyroidism compared to the euthyroid state.


Assuntos
Proliferação de Células/efeitos dos fármacos , Mitógenos/farmacologia , Neuroimunomodulação/imunologia , Receptores Adrenérgicos beta/efeitos dos fármacos , Linfócitos T/metabolismo , Glândula Tireoide/metabolismo , Agonistas Adrenérgicos beta/farmacologia , Animais , AMP Cíclico/metabolismo , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/imunologia , Feminino , Hipertireoidismo/induzido quimicamente , Hipertireoidismo/imunologia , Hipertireoidismo/metabolismo , Hipotireoidismo/induzido quimicamente , Hipotireoidismo/imunologia , Hipotireoidismo/metabolismo , Isoproterenol/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Neuroimunomodulação/genética , Propiltiouracila/farmacologia , Proteína Quinase C/metabolismo , Transporte Proteico/efeitos dos fármacos , Transporte Proteico/imunologia , Agregação de Receptores/efeitos dos fármacos , Agregação de Receptores/imunologia , Receptores Adrenérgicos beta/imunologia , Receptores Adrenérgicos beta/metabolismo , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Timidina/metabolismo , Glândula Tireoide/imunologia , Tiroxina/farmacologia
11.
Arch Latinoam Nutr ; 53(2): 119-32, 2003 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-14528601

RESUMO

Iron is an essential micronutrient involved in multiple biochemical and physiological process. In this review we discuss the most relevant aspect of its metabolism in order to reach a better comprehension of the relevant roll that this micronutrient plays in human health.


Assuntos
Ferro/metabolismo , Micronutrientes/metabolismo , Absorção , Humanos , Ferro/farmacocinética , Micronutrientes/farmacocinética
12.
Biol Trace Elem Res ; 94(1): 73-8, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12907829

RESUMO

The iron bioavailability and acute oral toxicity in rats of a ferrous gluconate compound stabilized with glycine (SFG), designed for food fortification, was studied in this work by means of the prophylactic method and the Wilcoxon method, respectively. For the former studies, SFG was homogeneously added to a basal diet of low iron content, reaching a final iron concentration of 20.1 +/- 2.4 mg Fe/kg diet. A reference standard diet using ferrous sulfate as an iron-fortifying source (19.0 +/- 2.1 mg Fe/kg diet) and a control diet without iron additions (9.3 +/- 1.4 mg Fe/kg diet) were prepared in the laboratory in a similar way. These diets were administered to three different groups of weaning rats during 23 d as the only type of solid nourishment. The iron bioavailability of SFG was calculated as the relationship between the mass of iron incorporated into hemoglobin during the treatment and the total iron intake per animal. This parameter resulted in 36.6 +/- 6.2% for SFG, whereas a value of 35.4 +/- 8.0% was obtained for ferrous sulfate. The acute toxicological studies were performed in two groups of 70 female and 70 male Sprague-Dawley rats that were administered increasing doses of iron from SFG. The LD50 values of 1775 and 1831 mg SFG/kg body wt were obtained for female and male rats, respectively, evidencing that SFG can be considered as a safe compound from a toxicological point of view.


Assuntos
Compostos Ferrosos/metabolismo , Compostos Ferrosos/toxicidade , Alimentos Fortificados/toxicidade , Ferro/metabolismo , Animais , Disponibilidade Biológica , Feminino , Masculino , Ratos , Ratos Sprague-Dawley
13.
Biol Trace Elem Res ; 92(3): 189-212, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12794272

RESUMO

Iron plays many roles in human physiology. In this article, we summarize the basic and current knowledge of this essential micronutrient on human metabolism.


Assuntos
Ferro/metabolismo , Animais , Transporte Biológico , Células/metabolismo , Humanos , Absorção Intestinal/fisiologia , Ferro/sangue , Ferro/farmacocinética , Ferro/fisiologia , Estado Nutricional , Distribuição Tecidual
14.
J Nutr Sci Vitaminol (Tokyo) ; 48(4): 315-7, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12489824

RESUMO

Microencapsulated ferrous sulfate (SFE-171) and ferric orthophosphate in Petit-Suisse cheese were examined for iron bioavailability by the prophylactic method. The iron sources were industrially added to different samples of Petit-Suisse cheese, which were mixed with other food components in our laboratory before use. A reference standard diet inclusive of nonmicroencapsulated ferrous sulfate and a control diet low in iron content were prepared in the laboratory. The final iron content in the fortified diets was approximately 15 mg Fe/kg diet. These diets were administered to weaning rats for 23 days. The iron bioavailability was evaluated as the ratio of iron incorporated into hemoglobin to oral iron intake, thereby being estimated as 62.6 +/- 8.8% for ferrous sulfate and 59.2 +/- 10.6% for SFE-171, which were significantly effective at p < 0.01 compared to 43.4 +/- 10.5% for ferric orthophosphate. It thus turned out that SFE-171 was stable through industrial processing with Petit-Suisse cheese as the food vehicle and served as an iron fortifier equal to ferrous sulfate in bioavailability.


Assuntos
Anemia Ferropriva/prevenção & controle , Queijo , Alimentos Fortificados , Hemoglobinas/química , Ferro da Dieta/farmacocinética , Administração Oral , Animais , Disponibilidade Biológica , Queijo/análise , Composição de Medicamentos , Feminino , Compostos Férricos/farmacocinética , Compostos Ferrosos/farmacocinética , Fosfatidilcolinas/farmacocinética , Ratos , Ratos Sprague-Dawley , Desmame
15.
J Exp Ther Oncol ; 2(2): 77-84, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12415623

RESUMO

The overlapping of three-dimensional structures of 5,6-dihydrobenzo(a)carbazole (DHBC) derivatives over the structure of 4-hydroxytamoxifen (4-OH-TAM), by means of the MDL CHEMLAB 11.0 computational program, shows a reasonable structural and spatial resemblance. This finding raised the hypothesis of their possible antitumoral activity, similar to that of tamoxifen (TAM). A number of DHBCs with an alkyl chain and a second basic nitrogen as substituent were synthesized in our laboratory and their possible antitumoral activity was tested by means of: 1) competitive radioligand assays to determine relative drug affinity for the estrogen receptor (ER); 2) in vivo studies, giving the synthetic drugs subcutaneously (1 mg kg-1 day-1) to Sprague-Dawley rats with N-nitroso-N-methylurea (NMU)-induced mammary tumors; and 3) in vitro cell proliferation experiments employing the soft agar clonogenic technique. Besides, studies on toxicity and histopathological analyses of organs and tumors from treated animals were performed. Results obtained showed that: 1) relative binding affinities (RBA) for the ER were similar to that of TAM; 2) some structures showed significant antitumoral activity and induced tumoral regression similar to TAM; and 3) these compounds had in vitro inhibitory effect on cell proliferation. Even though all the compounds of the series of synthesized DHBCs showed affinity for the ER similar to TAM, the results of in vivo experiments confirmed the crucial role of hydroxyl groups in the molecule and of the interatomic distance between them, similar to that of estradiol, as well as the necessary presence of the aminoalkyl chain on the annular N atom. However, the effect of alkyl chain enlargement in the nitrogen substituent on the biological activity of those drugs is as yet unclear.


Assuntos
Antineoplásicos/farmacologia , Carbazóis/farmacologia , Animais , Estradiol/metabolismo , Feminino , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Mamárias Experimentais/tratamento farmacológico , Neoplasias Mamárias Experimentais/patologia , Metilnitrosoureia , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Tamoxifeno/farmacologia
16.
Food Nutr Bull ; 23(3 Suppl): 195-8, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12362794

RESUMO

We compared the absorption of BioZn, SFE-171, SO4Fe (reference standard) and SO4Zn (reference standard) alone or in combination in water and in an infant dessert. When mineral interactions were evaluated, zinc and iron were administered in a 1:1 molar relation. There 160 rats divided in 16 groups of 10 animals each which received: SO(4)65Zn, Bio65Zn, SO(4)65Zn + SO4Fe, Bio65Zn + SFE-171, SO(4)59Fe, 59SFE-171, SO(4)59Fe + SO4Zn and 59SFE-171 + BioZn either in water or an infant dessert. The results showed that BioZn has bioavailability similar to SO4Zn both in water (23.36 +/- 3.14% vs. 21.48 +/- 6.03%. respectively) and in an infant dessert (19.89 +/- 3.27% vs. 18.31 +/- 4.76%, respectively). When these zinc compounds were administered with iron no statistical difference of zinc absorption was found (Bio65Zn + SFE-171 in water 22.70 +/- 6.30%, Bio65Zn + SFE-171 in the infant dessert 18.07 +/- 5.89%, SO(4)65Zn + SO4Fe in water 24.67 +/- 5.70% and SO(4)65Zn + SO4Fe in the infant desert 20.56 +/- 5.20%). For iron, the absorption of 59SFE-171 in water was higher (p < .01) than SO(4)59Fe in water and 59SFE-171 + BioZn in water (32.35 +/- 8.32% vs. 26.27 +/- 8.83% vs. 23.69 +/- 8.37%, respectively). Iron absorption from SO(4)59Fe in water was higher (p < .01) than SO(4)59Fe + SO4Zn in water (26.27 +/- 8.83% vs. 20.21 +/- 8.72%, respectively). Iron absorption in the infant dessert was higher (p < .01) for 59SFE-171 + BioZn than SO(4)59Fe, 59SFE-171 and SO(4)59Fe + SO4Zn (22.81 +/- 6.97% vs. 16.12 +/- 6.14% vs. 16.90 +/- 6.23% vs. 15.04 +/- 6.25%, respectively). Statistical differences (p < .01) were found between iron absorption from 59SFE-171 in water and the infant dessert (32.35 +/- 8.32% vs. 16.90 +/- 6.23%, respectively) and for SO(4)59Fe (26.27 +/- 8.83% vs. 16.12 +/- 6.14% respectively). Zinc and iron interactions evaluated in a 1:1 molar relation of the minerals were observed only for iron absorption in water but not in infant dessert. No negative effect was found for zinc absorption neither in water nor in infant dessert.


Assuntos
Absorção Intestinal/efeitos dos fármacos , Ferro/farmacocinética , Zinco/farmacocinética , Animais , Interações Medicamentosas , Feminino , Análise de Alimentos , Ferro/administração & dosagem , Ferro/farmacologia , Valor Nutritivo , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Zinco/administração & dosagem , Zinco/farmacologia
17.
J Wildl Dis ; 38(3): 644-8, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12238390

RESUMO

Gastrointestinal lesions have been extensively reported in wild and captive marine mammals. However, their etiology remains unclear. In humans and other animals, chronic gastritis and peptic ulcers have been associated with Helicobacter sp. Therefore, the aim of our study was to investigate the presence of Helicobacter sp. in the gastric juice, dental plaque, and saliva of marine mammals living in a controlled environment. Five dolphins (Tursiops gephyreus), one killer whale (Orcinus orca), one false killer whale (Pseudorca crassidens), three sea lions (Otaria flavescens), two elephant seals (Mirounga leonina), and two fur seals (Arctocephalus australis) were studied. Saliva, dental plaque, and gastric juice samples were examined for Helicobacter sp. using polymerase chain reaction. None of the gastric juice or saliva samples were positive for Helicobacter sp. However, Helicobacter sp. DNA was detected in dental plaque from two dolphins, suggesting the oral cavity might be a reservoir of this bacterium.


Assuntos
Placa Dentária/veterinária , Golfinhos , Infecções por Helicobacter/veterinária , Helicobacter/isolamento & purificação , Animais , Animais de Zoológico , DNA Bacteriano/análise , Placa Dentária/microbiologia , Feminino , Suco Gástrico/química , Suco Gástrico/microbiologia , Gastrite/microbiologia , Gastrite/veterinária , Helicobacter/genética , Infecções por Helicobacter/microbiologia , Masculino , Reação em Cadeia da Polimerase/veterinária , Saliva/microbiologia , Focas Verdadeiras
18.
Nutrition ; 18(6): 510-9, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12044825

RESUMO

This review concerns the importance of zinc in growth, development, and cognitive function in children and the deleterious consequences of its deficiency on children's health. Possible strategies to overcome zinc deficiency and the results of some supplementation trials are discussed.


Assuntos
Desenvolvimento Infantil/efeitos dos fármacos , Desenvolvimento Embrionário e Fetal/efeitos dos fármacos , Crescimento/efeitos dos fármacos , Zinco/farmacologia , Zinco/fisiologia , Estatura/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Criança , Desenvolvimento Infantil/fisiologia , Pré-Escolar , Cognição/efeitos dos fármacos , Cognição/fisiologia , Desenvolvimento Embrionário e Fetal/fisiologia , Feminino , Crescimento/fisiologia , Humanos , Lactente , Lactação/metabolismo , Masculino , Gravidez , Zinco/deficiência
19.
Nutrition ; 18(3): 279-81, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11882404

RESUMO

OBJECTIVE: We investigated the iron bioavailability of microencapsulated ferrous sulfate (SFE-171) in a diet based on powdered milk by using the prophylactic method in rats. METHODS: The SFE-171 was added into fluid milk and industrially processed into powdered milk, which was then mixed in our laboratory with a normalized diet (17.2 +/- 2.1 mg Fe/kg). A reference standard diet using ferrous sulfate as iron-fortifying source (19.8 p+/- 2.9 mg Fe/kg) and a control diet without added iron (4.6 +/- 0.8 mg Fe/kg) were prepared in the laboratory in a similar way. These diets were administered to different groups of weaning rats for 28 d as the only solid nourishment. The iron bioavailability of the different sources was calculated as the relation between the mass of iron incorporated into hemoglobin during the treatment and the total iron intake per animal. RESULTS: The iron bioavailability values of SFE-171 and ferrous sulfate in the fortified diets were 41.6 +/- 6.6% and 42.6 +/- 4.2%, respectively; these results were significantly higher (P < 0.01) than the iron bioavailability of the control diet (28.8 +/- 8.1%). CONCLUSION: These results showed that iron-fortified powdered milk can be produced from fluid milk fortified with SFE-171. The bioavailability of SFE-171 in this rat model was not altered by the manufacturing process.


Assuntos
Anemia Ferropriva/prevenção & controle , Compostos Ferrosos/farmacocinética , Alimentos Fortificados/normas , Ferro da Dieta/sangue , Leite/química , Animais , Disponibilidade Biológica , Composição de Medicamentos , Feminino , Leite/metabolismo , Ratos , Ratos Sprague-Dawley , Desmame
20.
Nutr Rev ; 60(2): 52-8, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11852970

RESUMO

Food fortification is an important strategy to combat iron and zinc deficiency. This review covers the basic concepts of food fortification, as well as its advantages and disadvantages. The main characteristics of the most common zinc and iron compounds used in this procedure are also analyzed.


Assuntos
Deficiências Nutricionais/prevenção & controle , Alimentos Fortificados , Deficiências de Ferro , Zinco/deficiência , Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...