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1.
Clin Exp Immunol ; 197(1): 36-51, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30864147

RESUMO

Regulatory T (Treg ) cells represent an essential component of peripheral tolerance. Given their potently immunosuppressive functions that is orchestrated by the lineage-defining transcription factor forkhead box protein 3 (FoxP3), clinical modulation of these cells in autoimmunity and cancer is a promising therapeutic target. However, recent evidence in mice and humans indicates that Treg cells represent a phenotypically and functionally heterogeneic population. Indeed, both suppressive and non-suppressive Treg cells exist in human blood that are otherwise indistinguishable from one another using classical Treg cell markers such as CD25 and FoxP3. Moreover, murine Treg cells display a degree of plasticity through which they acquire the trafficking pathways needed to home to tissues containing target effector T (Teff ) cells. However, this plasticity can also result in Treg cell lineage instability and acquisition of proinflammatory Teff cell functions. Consequently, these dysfunctional CD4+ FoxP3+ T cells in human and mouse may fail to maintain peripheral tolerance and instead support immunopathology. The mechanisms driving human Treg cell dysfunction are largely undefined, and obscured by the scarcity of reliable immunophenotypical markers and the disregard paid to Treg cell antigen-specificity in functional assays. Here, we review the mechanisms controlling the stability of the FoxP3+ Treg cell lineage phenotype. Particular attention will be paid to the developmental and functional heterogeneity of human Treg cells, and how abrogating these mechanisms can lead to lineage instability and Treg cell dysfunction in diseases like immunodysregulation polyendocrinopathy enteropathy X-linked (IPEX) syndrome, type 1 diabetes, rheumatoid arthritis and cancer.


Assuntos
Fatores de Transcrição Forkhead/imunologia , Linfócitos T Reguladores/imunologia , Artrite Reumatoide/etiologia , Artrite Reumatoide/imunologia , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Linhagem da Célula/genética , Linhagem da Célula/imunologia , Diabetes Mellitus Tipo 1/congênito , Diabetes Mellitus Tipo 1/etiologia , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/imunologia , Diarreia/genética , Diarreia/imunologia , Epigênese Genética , Fatores de Transcrição Forkhead/deficiência , Fatores de Transcrição Forkhead/genética , Doenças Genéticas Ligadas ao Cromossomo X/genética , Doenças Genéticas Ligadas ao Cromossomo X/imunologia , Humanos , Doenças do Sistema Imunitário/congênito , Doenças do Sistema Imunitário/genética , Doenças do Sistema Imunitário/imunologia , Imunoterapia , Inflamação/etiologia , Inflamação/imunologia , Modelos Imunológicos , Neoplasias/imunologia , Tolerância Periférica , Receptores de Antígenos de Linfócitos T/imunologia , Transdução de Sinais/imunologia , Linfócitos T Reguladores/classificação , Linfócitos T Reguladores/citologia , Pesquisa Translacional Biomédica
2.
J Food Sci Technol ; 55(1): 42-51, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29358794

RESUMO

Yam (Dioscorea spp) is an essential tuber crop for hundreds of millions of people in many African, Asian and South American countries. Considering in particular Southwest Nigeria, chips, flakes and flours are amongst the most common shelf-stable traditionally-processed yam products. This paper reports a systematic study on the proximate (moisture, protein, carbohydrate, fibre, fat, ash and gross energy) and mineral composition of these three food commodities sold in Nigerian markets. Results showed no significant differences in the moisture, crude protein and fibre content of all samples (10.0-12.3, 2.7-4.3 and 1.3-2.0 wt%, respectively). Gross energy was also comparable for all yam derived food items (between 3300 and 3507 kcal/kg), contradicting the common belief that yam flakes have lower nutritional value than chips and flours. Considering the mineral composition, Ca, Mg, P and K were the predominant macronutrients. Micronutrients such as Zn, Co, Mn and Cu were also detected. Significant differences existed between products, and their various sources (markets). Principal component analysis showed a direct correlation between ash content of the samples and the assessed macronutrients, irrespective of the market, or the seller of the commodities. This study confirmed that yam derived food stuffs have an adequate nutritional composition, irrespective of their form and/or origin.

3.
J Environ Manage ; 193: 79-91, 2017 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-28189932

RESUMO

Calcium hydroxyapatite Ca10(PO4)6(OH)2 (HAp) is a material widely used in biomedicine, for bone implants manufacture, due to its biocompatibility. HAp has also application for environmental remediation, as it can be employed as metal removal; moreover, it has the capability of effectively adsorbing organic molecules its surface. In recent years, the photocatalytic properties of HAp have been investigated; indeed several studies report of HAp used as photocatalyst, either on its own or combined with other photocatalytic materials. Although in the majority of cases the activity was induced by UV light, some reports of visible light-activated materials were reported. Here we present a critical review of the latest developments for HAp-based photocatalysts; the materials discussed are undoped single phase HAp, doped HAp and HAp-containing composites. For undoped single phase HAp, the possible surface treatment and lattice defects which can lead to a photoactive material are discussed. Considering doped HAp, the use of Ti4+ (the most common dopant) is described, with particular attention to the effects that this metal have on the characteristics of the material (i.e. crystallinity) and on its photocatalytic behaviour. The use of other dopants is also discussed. For the multiphasic materials, the combination of HAp with other photocatalysts is discussed, mainly but not only with titanium dioxide TiO2. Overall, HAp is a compound with high potential as photocatalyst; this property, combined with its capability for heavy metal removal, makes it a multifunctional material for environmental remediation. As future perspectives, further studies, based on the results obtained until present, should be performed, to improve the performance of the materials and/or shift the band gap into the visible. The use of other dopants and/or the combination with other photocatalysts, for instance, are features which is worth exploring.


Assuntos
Durapatita , Titânio , Adsorção , Catálise , Luz , Raios Ultravioleta
4.
J Environ Manage ; 182: 486-495, 2016 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-27526086

RESUMO

Pharmaceutical persistent pollutants pose a serious threat to the environment. The aim of this study was to use, for the first time, hydroxyapatite-based biomaterials as photocatalysts to degrade micropollutants. Diclofenac and fluoxetine were selected for these initial tests. Hydroxyapatite (Ca10(PO4)(OH)2, HAp) is one of the most commonly used biomaterials/bioceramics, being a major constituent of bone. In this work sustainable HAp-based materials of marine origin, obtained from cod fish bones, were used; these photocatalysts were previously fully studied and characterised. Both single-phase HAp and HAp-titania multicomponent materials (1 wt% TiO2) were employed as UV light photocatalysts, the latter showing better performance, indicated by higher degradation rates of both compounds. The HAp-titania photocatalyst showed excellent degradation of both persistent pollutants, the maximum degradation performance being 100% for fluoxetine and 92% for diclofenac, with pollutant and photocatalyst concentrations of 2 ppm and 4 g/L, respectively. Variations in features such as pollutant and photocatalyst concentrations were investigated, and results showed that generally fluoxetine was degraded more easily than diclofenac. The photocatalyst's crystallinity was not affected by the photodegradation reaction; indeed the material exhibited good photostability, as the degradation rate did not decrease when the material was reused. Tests were also performed using actual treated wastewater; the photocatalyst was still effective, even if with lower efficiency (-20% and -4% for diclofenac and fluoxetine, respectively). TOC analysis showed high but incomplete mineralisation of the pollutants (maximum 60% and 80% for DCF and FXT, respectively).


Assuntos
Materiais Biocompatíveis/química , Diclofenaco/química , Durapatita/química , Fotólise , Águas Residuárias/química , Poluentes Químicos da Água/análise , Acetonitrilas/química , Catálise , Cristalização , Monitoramento Ambiental/métodos , Recuperação e Remediação Ambiental , Fluoxetina/química , Oxigênio/química , Preparações Farmacêuticas/análise , Pós , Titânio/química , Raios Ultravioleta , Purificação da Água/métodos
5.
Genes Immun ; 15(5): 320-32, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24848930

RESUMO

Genetic and immunological analysis of host-pathogen interactions can reveal fundamental mechanisms of susceptibility and resistance to infection. Modeling human infectious diseases among inbred mouse strains is a proven approach but is limited by naturally occurring genetic diversity. Using N-ethyl-N-nitrosourea mutagenesis, we created a recessive loss-of-function point mutation in Unc93b1 (unc-93 homolog B1 (C. elegans)), a chaperone for endosomal Toll-like receptors (TLR)3, TLR7 and TLR9, which we termed Letr for 'loss of endosomal TLR response'. We used Unc93b1(Letr/Letr) mice to study the role of Unc93b1 in the immune response to influenza A/PR/8/34 (H1N1), an important global respiratory pathogen. During the early phase of infection, Unc93b1(Letr/Letr) mice had fewer activated exudate macrophages and decreased expression of CXCL10, interferon (IFN)-γ and type I IFN. Mutation of Unc93b1 also led to reduced expression of the CD69 activation marker and a concomitant increase in the CD62L naive marker on CD4(+) and CD8(+) T cells in infected lungs. Finally, loss of endosomal TLR signaling resulted in delayed viral clearance that coincided with increased tissue pathology during infection. Taken together, these findings establish a role for Unc93b1 and endosomal TLRs in the activation of both myeloid and lymphoid cells during the innate immune response to influenza.


Assuntos
Ativação Linfocitária , Ativação de Macrófagos , Proteínas de Membrana Transportadoras/genética , Mutação , Infecções por Orthomyxoviridae/imunologia , Processamento Alternativo , Animais , Linfócitos T CD8-Positivos/metabolismo , Quimiocina CXCL10/genética , Quimiocina CXCL10/metabolismo , Endossomos/metabolismo , Etilnitrosoureia , Imunidade Inata , Vírus da Influenza A Subtipo H1N1/patogenicidade , Interferon Tipo I/genética , Interferon Tipo I/metabolismo , Interferon gama/genética , Interferon gama/metabolismo , Selectina L/genética , Selectina L/metabolismo , Pulmão/metabolismo , Pulmão/patologia , Proteínas de Membrana Transportadoras/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Infecções por Orthomyxoviridae/genética , Receptores Toll-Like/genética , Receptores Toll-Like/metabolismo
7.
Clin Exp Immunol ; 175(3): 485-97, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24237155

RESUMO

The type 1 diabetes-associated 16p13 locus contains the CLEC16A gene. Its preferential immune cell expression suggests involvement in autoimmunity. Given its elevated expression in dendritic and B cells - known professional antigen-presenting cells (APCs) - we hypothesize that C-type lectin domain family 16 member A (CLEC16A) may be involved in T cell co-stimulation and consequent activation and proliferation. We also sought to identify CLEC16A's subcellular localization. The effect of the CLEC16A knock-down (KD) on B cell co-stimulation and activation of T cells was tested in human lymphoblastoid cell lines (LCLs) by co-culture with CD4(+) T cells. T cell activation and proliferation were determined by flow-cytometric analysis of CD69 and CD25 expression and carboxyfluorescein succinimidyl ester (CFSE) dilution, respectively. CLEC16A subcellular localization in K562 cells was examined by immunofluorescence. We show that the CLEC16A KD did not affect the tested indices of lymphoblastoid cell line (LCL) APC capacity. Additionally, the percentage of activated T cells following LCL co-culture was not affected significantly by the CLEC16A KD. T cells co-cultured with KD or control LCLs also exhibited similar cell division profiles. CLEC16A co-localized with an endoplasmic reticulum (ER) marker, suggesting that it may be an ER protein. In conclusion, CLEC16A may not be involved in T cell co-stimulation. Additional studies on CLEC16A, accounting for its ER localization, are needed to uncover its biological role.


Assuntos
Cromossomos Humanos Par 16 , Loci Gênicos , Lectinas Tipo C/genética , Proteínas de Transporte de Monossacarídeos/genética , Células Apresentadoras de Antígenos/metabolismo , Linfócitos B/metabolismo , Técnicas de Cocultura , Retículo Endoplasmático/metabolismo , Técnicas de Silenciamento de Genes , Humanos , Células K562 , Lectinas Tipo C/metabolismo , Leucócitos Mononucleares/metabolismo , Ativação Linfocitária/imunologia , Proteínas de Transporte de Monossacarídeos/metabolismo , Transporte Proteico , Linfócitos T/imunologia , Linfócitos T/metabolismo
8.
J Environ Manage ; 121: 87-95, 2013 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-23524400

RESUMO

Selected bacterial strains were immobilised on the surface of hydroxyapatite (Ca10(PO4)6(OH)2 - HAp) of natural origin (fish bones). The capacity of the material, alone and in combination with the bacterial strains to act as heavy metal removers from aqueous streams was assessed. Pseudomonas fluorescens (S3X), Microbacterium oxydans (EC29) and Cupriavidus sp. (1C2) were chosen based on their resistance to heavy metals and capacity of adsorbing the metals. These systems were tested using solutions of Zn(II), Cd(II) and in solutions containing both metals. A synergistic effect between the strains and HAp, which is effective in removing the target heavy metals on its own, was observed, as the combination of HAp with the bacterial strains led to higher adsorption capacity for both elements. For the solutions containing only one metal the synergistic effect was greater for higher metal concentrations; 1C2 and EC29 were the most effective strains for Zn(II) and Cd(II) respectively, while S3X was less effective. Overall, an almost four-fold increase was observed for the maximum adsorption capacity for Zn(II) when 1C2 was employed - 0.433 mmol/g in comparison of 0.121 mmol/g for the unmodified HAp. For Cd(II), on the other hand, an almost three-fold increase was registered with EC29 bacterial strain - 0.090 vs 0.036 mmol/g for the unmodified HAp. When the solutions containing both metals were tested, the effect was more marked for lower concentrations.


Assuntos
Biofilmes , Cupriavidus/metabolismo , Durapatita , Metais Pesados/isolamento & purificação , Pseudomonas fluorescens/metabolismo , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Animais , Osso e Ossos , Gadus morhua , Metais Pesados/metabolismo , Poluentes Químicos da Água/metabolismo
9.
Neoplasia ; 36: 100874, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36638586

RESUMO

Despite marked success in treatment with immune checkpoint inhibitor (CPI), only a third of patients are responsive. Thus, melanoma still has one of the highest prevalence and mortality rates; which has led to a search for novel combination therapies that might complement CPI. Aberrant methylomes are one of the mechanisms of resistance to CPI therapy. S-adenosylmethionine (SAM), methyl donor of important epigenetic processes, has significant anti-cancer effects in several malignancies; however, SAM's effect has never been extensively investigated in melanoma. We demonstrate that SAM modulates phenotype switching of melanoma cells and directs the cells towards differentiation indicated by increased melanogenesis (melanin and melanosome synthesis), melanocyte-like morphology, elevated Mitf and Mitf activators' expression, increased antigen expression, reduced proliferation, and reduced stemness genes' expression. Consistently, providing SAM orally, reduced tumor growth and progression, and metastasis of syngeneic BRAF mutant and wild-type (WT) melanoma mouse models. Of note, SAM and anti-PD-1 antibody combination treatment had enhanced anti-cancer efficacy compared to monotherapies, showed significant reduction in tumor growth and progression, and increased survival. Furthermore, SAM and anti-PD-1 antibody combination triggered significantly higher immune cell infiltration, higher CD8+ T cells infiltration and effector functions, and polyfunctionality of CD8+ T cells in YUMMER1.7 tumors. Therefore, SAM combined with CPI provides a novel therapeutic strategy against BRAF mutant and WT melanomas and provides potential to be translated into clinic.


Assuntos
Inibidores de Checkpoint Imunológico , Melanoma , Animais , Camundongos , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Proteínas Proto-Oncogênicas B-raf/genética , S-Adenosilmetionina/farmacologia , S-Adenosilmetionina/uso terapêutico , Linfócitos T CD8-Positivos , Melanoma/tratamento farmacológico , Melanoma/genética , Melanoma/patologia , Carcinogênese , Transformação Celular Neoplásica
10.
World J Microbiol Biotechnol ; 28(6): 2435-40, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22806118

RESUMO

The aim of this work is to study the conversion of oleuropein-a polyphenol present in olives and olive oil by-products-into hydroxytyrosol, a polyphenol with antioxidant and antibacterial properties. The hydrolysis reaction is performed by lactic acid bacteria. Six bacterial strains (Lactobacillus plantarum 6907, Lactobacillus paracasei 9192, Lactobacillus casei, Bifidobacterium lactis BO, Enterococcus faecium 32, Lactobacillus LAFTI 10) were tested under aerobic and anaerobic conditions. The oleuropein degradation and hydroxytyrosol formation were monitored by HPLC. Results showed that oleuropein could be successfully converted into hydroxytyrosol. The most effective strain was Lactobacillus plantarum 6907, with a reaction yield of hydroxytyrosol of about 30 %. Different reaction mechanisms were observed for different microorganisms; a different yield was observed for Lactobacillus paracasei 9192 under aerobic or anaerobic conditions and an intermediate metabolite (oleuropein aglycone) was detected for Lactobacillus paracasei 9192 and Lactobacillus plantarum 6907 only. This study could have significant applications, as this reaction can be used to increase the value of olive oil by-products and/or to improve the taste of unripe olives.


Assuntos
Lactobacillus/metabolismo , Álcool Feniletílico/análogos & derivados , Piranos/metabolismo , Glucosídeos Iridoides , Iridoides , Olea/microbiologia , Álcool Feniletílico/metabolismo
11.
Clin Exp Allergy ; 41(5): 718-28, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21255135

RESUMO

BACKGROUND: Intravenous immunoglobulin (IVIG) has potent anti-inflammatory and immune-modulating properties. IVIG has been utilized as a steroid-sparing agent in severe asthma, but the results of clinical trials have been conflicting. OBJECTIVE: To determine whether IVIG is able to attenuate bronchial reactivity, pulmonary inflammation and T cell function using a murine model of allergic airways disease. METHODS: BALB/c or C57BL/6 mice were sensitized to ovalbumin (OVA) or a phosphate-buffered saline control using local nasal sensitization, and then received five intranasal challenges on days 28-32 before sacrifice. Mice were treated intraperitoneally with either IVIG (1-2 g/kg) or equivalent human serum albumin 24 h before the first OVA challenge. Bronchial reactivity to methacholine was examined using the FlexiVent small animal ventilator. We evaluated pulmonary histology, mRNA from lung digests for T-helper type 2 (Th2)-related genes and bronchoalveolar lavage for cell counts and cytokines. Splenocytes were utilized to study OVA-induced cell proliferation, cytokine production and dendritic cell maturation. RESULTS: IVIG markedly attenuated the perivascular and peribronchial pulmonary inflammation, and decreased bronchial hyperresponsiveness to methacholine. IVIG treatment of splenocytes from sensitized animals diminished cellular proliferation to OVA, whereas IVIG treatment in vivo markedly attenuated OVA-driven splenocyte proliferation. This is accompanied by diminished IL-13 and TNF-α levels in splenocyte culture, decreased expression of Jagged-1, increased Delta-4 and decreased GATA-3 mRNA levels, signs that IVIG has suppressed the expected Th2 response that accompanies repeated allergen exposure. Increased regulatory T cells were found in draining pulmonary lymph nodes in IVIG-treated mice but not in controls. CONCLUSIONS AND CLINICAL RELEVANCE: IVIG was effective in ameliorating allergic airway disease in our model. IVIG may be a promising adjunct therapy requiring further study for patients with severe asthma.


Assuntos
Asma/imunologia , Hiper-Reatividade Brônquica/terapia , Imunoglobulinas Intravenosas/uso terapêutico , Modelos Imunológicos , Animais , Asma/induzido quimicamente , Hiper-Reatividade Brônquica/imunologia , Modelos Animais de Doenças , Humanos , Imunoglobulinas Intravenosas/imunologia , Injeções Intraperitoneais , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Ovalbumina , Albumina Sérica/administração & dosagem , Albumina Sérica/imunologia , Linfócitos T Reguladores/imunologia
12.
J Leukoc Biol ; 82(2): 335-46, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17475784

RESUMO

Although forkhead box p3 (Foxp3) expression is restricted to naturally occurring CD4(+) regulatory T cells (T(REG)), little is known about the various signals that regulate it in T cells. As TGF-beta has been reported to modulate Foxp3 expression in T cells, we investigated its effects on the induction or maintenance of regulatory functions in different CD4(+) T cell subsets. TGF-beta1 priming was able to promote differentiation of T(REG) cells from nonregulatory CD4(+)CD25(-) T cells in a concentration-dependent manner through Foxp3 induction. As CD4(+)CD25(-) T cells remain a highly heterogeneous population with variable degrees of antigen experience, we then examined the effect of TGF-beta1 on naive CD4(+)CD25(-)CD45RB(HIGH) T cells. Freshly isolated or TGF-beta1-treated CD4(+)CD25(-)CD45RB(HIGH) T cells never displayed any regulatory functions or significant Foxp3 expression following TCR activation. In stark contrast, freshly isolated CD4(+)CD25(-)CD45RB(LOW) cells, albeit expressing low levels of Foxp3 mRNA and protein, were unable to suppress CD4(+) effector T cell proliferation but acquired regulatory activity and de novo Foxp3 expression following TGF-beta1 exposure. Furthermore, suppression was IL-10-dependent, as anti-IL-10 receptor antibody treatment abrogated this suppression completely, consistent with the ability of TGF-beta1-treated CD4(+)CD25(-)CD45RB(LOW) to synthesize IL-10 upon restimulation in vitro. Last, we show that TGF-beta1 treatment or blockade did not lead to enhanced expansion or function of naturally occurring CD4(+)CD25(+) T(REG) cells, although it maintained Foxp3 mRNA and protein expression. Altogether, TGF-beta1 promotes the induction of IL-10-secreting CD4(+) T(REG) cells from CD4(+)CD25(-)CD45RB(LOW) precursors through de novo Foxp3 production and maintains natural T(REG) cell peripheral homeostasis by sustaining Foxp3 expression.


Assuntos
Antígenos CD4/análise , Fatores de Transcrição Forkhead/metabolismo , Subpopulações de Linfócitos T/imunologia , Linfócitos T Reguladores/imunologia , Fator de Crescimento Transformador beta1/farmacologia , Animais , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Citometria de Fluxo , Fatores de Transcrição Forkhead/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas de Fluorescência Verde/metabolismo , Tolerância Imunológica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos
13.
Mater Sci Eng C Mater Biol Appl ; 71: 141-149, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-27987691

RESUMO

The development of innovative, safe and non-photocatalytic sunscreens is urgently needed, as it is essential to have sunscreen filters offering appropriate UV protection without damaging the environment and/or generating free radicals when in contact with the skin. Hydroxyapatite (Ca10(PO4)6(OH)2, HAp) when substituted with iron has UV protection properties and is not photocatalytic; HAp was used to make a sunscreen filter by treating cod fish bones in an iron-containing solution, and then calcining them at 700°C. Here we present a systematic and advanced study on this material, to obtain a sunscreen with improved UV absorbing properties. Bones were treated with three different iron salts - Fe(II) chloride, Fe(II) lactate and Fe(III) nitrate - under various pH conditions. Results showed that Fe(II) chloride in basic pH led to the most effective iron inclusion. High energy ball milling or ultrasound were investigated to increase surface area and corresponding UV absorption; high energy ball milling treatment led to the best optical properties. The optimum powders were used to formulate UV protection creams, which showed Sun Protection Factor (SPF) values significantly superior to the control cream (up to 4.1). Moreover the critical wavelength (λcrit) was >370nm (388-389nm) and UVA/UVB ratios were very close to 1. With these properties these sunscreens can be classified as broad UV protectors. Results also showed that combining these powders with other sunscreens (i.e. titanium dioxide), a synergic effect between the different components was also observed. This investigation showed that HAp-based sunscreens of marine origin are a valid alternative to commercial products, safe for the health of the customers and, being non-photocatalytic, do not pose a threat to the environment.


Assuntos
Durapatita/química , Compostos Férricos/química , Compostos Férricos/síntese química , Protetores Solares/química , Protetores Solares/síntese química , Raios Ultravioleta
14.
Ann N Y Acad Sci ; 1051: 72-87, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16126946

RESUMO

Nonobese diabetic (NOD) mice serve as a model of spontaneous type 1 diabetes (T1D), a T cell-mediated autoimmune disease leading to the destruction of pancreatic insulin-producing beta islet cells. A possible deficiency in regulatory T (T(reg)) cell development or function may promote the activation, expansion, and recruitment of autoreactive T cells and the onset of T1D. Naturally occurring CD4(+)CD25(+) T(reg) (nT(reg)) cells, which typically display potent inhibitory effects on T cell functions in vitro and in vivo, may be defective at controlling autoimmunity in T1D. We have examined the relative contribution of CD4(+)CD25(+) nT(reg) cells in the immune regulation of T1D in the NOD mouse model. CD4(+)CD25(+) T cells represent 5-10% of CD4(+) thymocytes or peripheral T cells from prediabetic neonatal NOD mice, are anergic to TCR signals, and potently suppress activated T cells in a contact-dependent and cytokine-independent fashion in vitro. Unlike total CD4(+) T cells, prediabetic CD25(+)-depleted CD4(+) T cells are potently diabetogenic when transferred in immunodeficient NOD mice. Co-transfer of CD4(+)CD25(+) T cells from thymocytes or peripheral lymphoid tissues of neonatal NOD mice dramatically halts disease development and beta-islet cell lymphocytic infiltration, even when T1D is induced by CD4(+) T cells from BDC2.5 transgenic or diabetic NOD mice. Finally, we show that CD4(+)CD25(+) T(reg) preferentially accumulate in inflamed pancreatic environments, where they potently inhibit the antigen-specific expansion and cytokine effector functions of diabetogenic T cells. Thus, CD4(+)CD25(+) T cell-mediated regulation is operative in the prediabetic neonatal T cell repertoire and can suppress the diabetogenic process and control the onset of T1D.


Assuntos
Diabetes Mellitus Tipo 1/imunologia , Linfócitos T Reguladores/fisiologia , Animais , Animais Recém-Nascidos , Tolerância Imunológica , Camundongos , Camundongos Endogâmicos NOD , Pancreatite/imunologia , Receptores de Antígenos de Linfócitos T/fisiologia
15.
Mater Sci Eng C Mater Biol Appl ; 51: 309-15, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25842140

RESUMO

Single phase hydroxyapatite (HAp) and biphasic material hydroxyapatite/ß-tricalcium phosphate (HAp/ß-TCP) were obtained from a marine source (Atlantic cod fish bones). Here we report a study on the biological properties of these materials, including cytotoxicity, bioactivity and haemocompatibility. Results showed that the materials are not cytotoxic, neither in their powder nor in pellet form; indeed growth of Saos-2 cells was comparable to that of commercial. The haemolysis rate was lower than 2%; hence the materials can be classified as non-haemolytic. Moreover, when immersed in Simulated Body Fluid (SBF), crystal formation was observed on the surface of both materials. The sintering behaviour of the samples was also studied; both powders showed very high sinterability (density higher than 95% of the theoretical value). Overall, these results confirm the suitability of these materials for biomedical applications.


Assuntos
Produtos Biológicos/síntese química , Substitutos Ósseos/química , Osso e Ossos/química , Gadiformes/metabolismo , Hidroxiapatitas/química , Animais , Produtos Biológicos/toxicidade , Líquidos Corporais/química , Substitutos Ósseos/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Módulo de Elasticidade , Dureza , Temperatura Alta , Humanos , Hidroxiapatitas/toxicidade , Teste de Materiais
16.
Hum Gene Ther ; 10(12): 1915-22, 1999 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-10466625

RESUMO

Antiinflammatory cytokines such as transforming growth factor beta1 (TGF-beta1) and interleukin 4 (IL-4) can protect from autoimmune diseases. To study the immunoregulatory effects of these cytokines in vivo, we used a method of gene therapy that permits continuous cytokine delivery over a period of weeks. We injected naked plasmid DNA expression vectors encoding either TGF-beta1 (pVR-TGF-beta1) or an IL-4-IgG1 chimeric protein (pVR-IL-4-IgG1) intramuscularly. This resulted in production of TGF-beta1 or IL-4-IgG1, respectively, and protection from myelin basic protein (MBP)-induced experimental allergic encephalomyelitis (EAE). TGF-beta1 gene delivery had pronounced downregulatory effects on T cell proliferation and production of interferon gamma (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha), on in vitro restimulation with MBP. IL-4-IgG1 vector administration also suppressed these responses, although much less than TGF-beta1, and enhanced secretion of endogenous IL-4. Therapy resulted in a significant decrease in the severity of histopathologic inflammatory lesions. In the CNS, treatment with either vector suppressed IL-12 and IFN-gamma mRNA expression, while IL-4 and TGF-beta1 mRNA levels were increased compared with control mice. Thus, cytokine plasmid treatment appeared to inhibit MBP-specific pathogenic Thl responses, while enhancing endogenous secretion of protective cytokines. We demonstrate that gene therapy with these vectors is an effective therapeutic strategy for EAE.


Assuntos
Citocinas/genética , Encefalomielite Autoimune Experimental/prevenção & controle , Técnicas de Transferência de Genes , Terapia Genética , Vetores Genéticos/administração & dosagem , Plasmídeos/genética , Animais , Citocinas/imunologia , Citocinas/metabolismo , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/induzido quimicamente , Encefalomielite Autoimune Experimental/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Imunoglobulina G/genética , Imunoglobulina G/metabolismo , Injeções Intramusculares , Interleucina-4/genética , Interleucina-4/metabolismo , Ativação Linfocitária , Camundongos , Proteína Básica da Mielina/efeitos adversos , Reação em Cadeia da Polimerase , Proteínas Recombinantes de Fusão/imunologia , Linfócitos T/imunologia , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/imunologia
17.
J Neuroimmunol ; 49(1-2): 1-7, 1994 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8294548

RESUMO

Cytokine production by T cells in the cerebrospinal fluid (CSF) and central nervous system (CNS) of SJL/J mice during myelin basic protein (MBP)-induced experimental allergic encephalomyelitis (EAE) was examined. Reverse transcriptase/polymerase chain reaction (RT/PCR) was used to measure interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) mRNA levels from perfused CNS tissue (brain and spinal cord) and from cells isolated from CSF. Animals were grouped according to EAE severity, ranging from asymptomatic (adjuvant only) to severe disease (paralysis or severe paresis). Cytokine signals, normalized to actin, were almost undetectable in control tissues, and only slightly elevated in whole CNS tissue from animals with mild EAE. Both cytokine messages were strongly upregulated in CNS tissues derived from severely affected animals, consistent with previous observations correlating disease progression with infiltration by memory/effector CD4+ T cells, the major source of these cytokines. This cytokine upregulation was specific to the CNS, since other organs from the same animals did not express significant levels of IL-2 and IFN-gamma. CSF was obtained from the cisterna magna of unperfused mice and verified as such by absence of red blood cells (RBCs) and by immunoglobulin concentration orders of magnitude lower than in serum. Cytokine message was measured in RNA isolated from cells in CSF. Levels of IL-2 and IFN-gamma mRNA in CSF cells were significantly elevated in mild EAE and strongly upregulated in severe disease, correlating with those in total CNS tissue. These results confirm the CSF as representative of the immune status of the CNS and indicate a role for IL-2 and IFN-gamma in inflammatory CNS disease.


Assuntos
Encefalomielite Autoimune Experimental/metabolismo , Interferon gama/biossíntese , Interleucina-2/biossíntese , Animais , Sequência de Bases , Encefalomielite Autoimune Experimental/líquido cefalorraquidiano , Feminino , Expressão Gênica , Interferon gama/líquido cefalorraquidiano , Interferon gama/genética , Interleucina-2/líquido cefalorraquidiano , Interleucina-2/genética , Camundongos , Dados de Sequência Molecular , Linfócitos T/metabolismo
18.
Rapid Commun Mass Spectrom ; 14(14): 1179-83, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10918365

RESUMO

The influence of different RuO(2) crystallite sizes was investigated by secondary ion mass spectrometry (SIMS) on the oxide deposited on various support materials (Ni, Ti, Al(2)O(3), oxidized Si(100)). In order to examine the effect of an oxidic environment on the film structure, RuO(2) 20%-TiO(2) 80% at. mixed oxide was deposited on Ti. The polycrystalline coatings were prepared by heating the Ru (and Ti)-containing solution dropped on the supports.1 RuO(2) nanocrystalline coatings were grown by chemical vapor deposition (CVD) from Ru(COD)(eta(3)-allyl)(2).2 The identification of mixed oxide clusters showed the higher reactivity of Ni and Al(2)O(3) over the other substrates. Diffusion and migration characteristics were observed to be influenced by the nature of the support. The results are complementary to those of a previous SIMS investigation.3 Copyright 2000 John Wiley & Sons, Ltd.

19.
Minerva Ginecol ; 46(9): 491-3, 1994 Sep.
Artigo em Italiano | MEDLINE | ID: mdl-7984329

RESUMO

The Authors report the results of their research into the use of the alpha-interferon in the microcondylomatosis of the female genital apparatus. The therapy was successful in 18% of cases. Considering oncological risk connected with the permanency of the HPV in the uterine portio, the Authors consider they must continue the study on new diagnostic and therapeutic protocols.


Assuntos
Condiloma Acuminado/terapia , Doenças dos Genitais Femininos/terapia , Interferon-alfa/uso terapêutico , Estudos de Avaliação como Assunto , Feminino , Humanos
20.
J Mater Chem B ; 2(36): 5999-6009, 2014 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-32261852

RESUMO

The use of sunscreens as protective barriers against skin damage and cancer, by absorbing harmful UVA and UVB rays, is becoming an increasingly important issue. Such products are usually based on TiO2 or ZnO, although both Fe2O3 and hydroxyapatite (Ca10(PO4)6(OH)2, HAp) doped with metal ions have been reported as being ultraviolet (UV) absorbing materials. HAp is the main component of bone; it is, therefore, highly biocompatible. In the present work, an iron-doped HAp-based material, containing both Fe ions substituted into the HAp structure and iron oxide in hematite (α-Fe2O3) form, was successfully developed from waste cod fish bones. This was achieved through a simple process of treating the bones in a Fe(ii) containing solution, followed by heating at 700 °C. The material showed good absorption in the whole UV range and did not form radicals when irradiated. The sunscreen cream formulated with this material could be used as a broad sunscreen protector (λcrit > 370 nm), showing high absorption both in the UVA and UVB ranges. Because of its absorption properties it would be classified as 5 star protection according to the Boots UVA star rating system. The cream is also photostable, and does not cause irritation or erythema formation when in contact with the human skin. These results show that a food by-product such as fish bones could be converted into a valuable product, with potential applications in health care and cosmetics. This is the first time a HAp-based sunscreen cream has been developed and validated as a proof of concept.

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