Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Eur J Nutr ; 57(7): 2607-2619, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28913556

RESUMO

PURPOSE: Vitamin D may induce tolerance in the intestinal immune system and has been shown to regulate the phenotype of tolerogenic intestinal dendritic cells (DCs) in vitro. It is unknown whether vitamin D supplementation affects human intestinal DCs in vivo, and we aimed to investigate the tolerability and effect on intestinal CD103+DCs of high-dose vitamin D3 treatment in healthy subjects. METHODS: Ten healthy subjects received a total of 480,000 IU oral vitamin D3 over 15 days and colonic biopsies were obtained before and after intervention by endoscopy. Lamina propria mononuclear cells (LPMCs) were isolated from the biopsies, stained with DC surface markers and analysed with flow cytometry. Snap-frozen biopsies were analysed with qPCR for DC and regulatory T cell-related genes. RESULTS: No hypercalcemia or other adverse events occurred in the test subjects. Vitamin D decreased the number of CD103+ DCs among LPMCs (p = 0.006). Furthermore, vitamin D induced mRNA expression of TGF-ß (p = 0.048), TNF-α (p = 0.006) and PD-L1 (p = 0.02) and tended to induce IL-10 expression (p = 0.06). Multivariate factor analysis discriminated between pre- and post-vitamin D supplementation with a combined increased qPCR expression of PD1, PD-L1, TGF-ß, IL-10, CD80, CD86, FOXP3, NFATc2 and cathelicidin. CONCLUSION: High-dose vitamin D supplementation is well tolerated by healthy subjects and has a direct effect on the CD103+ DCs, local cytokine and surface marker mRNA expression in the colonic mucosa, suggestive of a shift towards a more tolerogenic milieu.


Assuntos
Colecalciferol/administração & dosagem , Colo/citologia , Células Dendríticas/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Células Dendríticas/imunologia , Relação Dose-Resposta a Droga , Voluntários Saudáveis , Humanos , Mucosa Intestinal/citologia , Linfócitos T Reguladores
2.
Sci Rep ; 7: 42873, 2017 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-28211468

RESUMO

The use of lubricants (solid or liquid) is a well-known and suitable approach to reduce friction and wear of moving machine components. Another possibility to influence the tribological behaviour is the formation of well-defined surface topographies such as dimples, bumps or lattice-like pattern geometries by laser surface texturing. However, both methods are limited in their effect: surface textures may be gradually destroyed by plastic deformation and lubricants may be removed from the contact area, therefore no longer properly protecting the contacting surfaces. The present study focuses on the combination of both methods as an integral solution, overcoming individual limitations of each method. Multiwall carbon nanotubes (MWCNT), a known solid lubricant, are deposited onto laser surface textured samples by electrophoretic deposition. The frictional behaviour is recorded by a tribometer and resulting wear tracks are analysed by scanning electron microscopy and Raman spectroscopy in order to reveal the acting tribological mechanisms. The combined approach shows an extended, minimum fivefold longevity of the lubrication and a significantly reduced degradation of the laser textures. Raman spectroscopy proves decelerated MWCNT degradation and oxide formation in the contact. Finally, a lubricant entrapping model based on surface texturing is proposed and demonstrated.

3.
Diabetologia ; 55(5): 1291-4, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22270224

RESUMO

AIMS/HYPOTHESIS: Vitamin D deficiency during the fetal period or infancy is one of the suggested environmental factors for type 1 diabetes and for its increasing incidence. To test this hypothesis we compared serum 25-hydroxyvitamin D (25(OH)D) levels during early pregnancy in mothers of children who subsequently developed type 1 diabetes (case mothers) with mothers of non-diabetic healthy children (control mothers) of the same age. METHODS: Children with type 1 diabetes were identified from the nationwide prescription register. 25(OH)D concentration was measured from serum samples collected during the first trimester of pregnancy from all Finnish women (Finnish Maternity Cohort). A total of 343 case mothers and 343 control mothers were included in the study. Samples were collected throughout the year. Samples from case and control mothers were matched on the day of collection. RESULTS: Mean 25(OH)D levels in case mothers (43.9 nmol/l) and control mothers (43.7 nmol/l) were not different. Of all mothers, 481 (70.1%) were vitamin D-deficient or -insufficient. CONCLUSIONS/INTERPRETATION: No difference was found in serum 25(OH)D concentrations during first trimester of pregnancy between mothers whose children later on developed type 1 diabetes, and mothers of non-diabetic ' healthy' children of the same age. It is difficult to detect possible effects of mothers' vitamin D deficiency during early pregnancy on the development of type 1 diabetes in the offspring in this population, as such a large proportion of mothers were vitamin D-deficient or -insufficient.


Assuntos
Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/epidemiologia , Gravidez/sangue , Vitamina D/análogos & derivados , Adulto , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Primeiro Trimestre da Gravidez/sangue , Risco , Vitamina D/sangue , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/epidemiologia
4.
J Hazard Mater ; 175(1-3): 779-88, 2010 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-19942347

RESUMO

Activated carbons were prepared by the pyrolysis of coffee grounds impregnated by phosphoric acid at 450 degrees C for different impregnation ratios: 30, 60, 120 and 180 wt.%. Materials were characterized for their surface chemistry by elemental analysis, "Boehm titrations", point of zero charge measurements, Infrared spectroscopy, thermogravimetric analysis (TGA); as well as for their porous and morphological structure by Scanning Electron Microscopy (SEM) and nitrogen adsorption at 77K. The impregnation ratio was found to govern the porous structure of the prepared activated carbons. Low impregnation ratios (<120 wt.%) led to essentially microporous and acidic activated carbons whereas high impregnation ratios (>120 wt.%) yielded to essentially mesoporous carbons with specific surface areas as high as 925 m(2)g(-1), pore volume as large as 0.7 cm(3)g(-1), and neutral surface. The activated carbons prepared from coffee grounds were compared to a commercial activated carbon (S(BET) approximately 1400 m(2)g(-1)) for their adsorption isotherms of methylene blue and "Nylosan Red N-2RBL", a cationic and anionic (azo) dye respectively. The mesoporous structure of the material produced at 180 wt.% H(3)PO(4) ratio was found to be appropriate for an efficient sorption of the latter azo dye.


Assuntos
Compostos Azo/química , Carbono/química , Azul de Metileno/química , Naftalenossulfonatos/química , Ácidos Fosfóricos/química , Adsorção , Café , Corantes/química , Concentração de Íons de Hidrogênio , Nitrogênio/química , Porosidade , Espectrofotometria Infravermelho/métodos , Propriedades de Superfície , Temperatura , Termogravimetria/métodos , Água/química
5.
Oncogene ; 26(16): 2283-9, 2007 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-17016429

RESUMO

We discovered a novel oncogene in a T-cell lymphoma cell line, multiple copies in T-cell lymphoma-1 (MCT-1), that has been shown to decrease cell-doubling time, shorten the duration of G(1) transit time and/or G(1)-S transition, and transform NIH3T3 fibroblasts. We subsequently demonstrated that there were significantly increased levels of MCT-1 protein in a subset of primary diffuse large B-cell lymphomas. Levels of MCT-1 protein were shown to be increased after exposure to DNA damaging agents. This increase did not require new protein synthesis, suggesting that post-translational mechanisms were involved. Phosphorylation is one potential mechanism by which the activity of molecules involved in cell cycle/survival is rapidly modulated. The RAS/mitogen-activated/extracellular-regulated kinase (MEK)/extracellular signal-regulated kinases (ERK) pathway plays a prominent role in the regulation of cell growth and proliferation through phosphorylation-dependent regulation of several substrates. The MCT-1 protein is predicted to have numerous putative phosphorylation sites. Using a combination of genetic and pharmacological approaches, we established that phosphorylation of MCT-1 protein by p44/p42 mitogen-activated protein kinases is critical for stabilization of MCT-1 protein and for its ability to promote cell proliferation. Our data suggests that targeting the RAS/MEK/ERK signal transduction cascade may provide a potential therapeutic approach in lymphomas and related malignancies that exhibit high levels of MCT-1 protein.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Dano ao DNA , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Proteínas Oncogênicas/metabolismo , Células 3T3 , Sequência de Aminoácidos , Animais , Ciclo Celular , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/genética , Divisão Celular , Linhagem Celular Tumoral , Sobrevivência Celular , Humanos , Células Jurkat , Cinética , Linfoma de Células T/genética , Linfoma de Células T/patologia , Camundongos , Dados de Sequência Molecular , Proteínas Oncogênicas/química , Proteínas Oncogênicas/genética , Fosforilação
6.
Environ Technol ; 25(9): 1059-65, 2004 Sep.
Artigo em Francês | MEDLINE | ID: mdl-15515272

RESUMO

The region of Skikda is one of the most important industrial poles of Algeria. The aim of the study is a qualitative and quantitative evaluation of the pollution by heavy metals of the marine water of the bay. The pollutants investigated are lead, cadmium and mercury because of their toxicity. The study is concerned mainly with the spatiotemporal evolution of the pollution on the extent of the bay. Concentrations of heavy metals metals vary from 4 microg l(-1) to 55 microg l(-1) for lead, 1 microg l(-1) to 17 microg l(-1) for cadmium and 0,1 to 1,1 microg l(-1) for mercury, which indicates a beginning of pollution of the site. Only small variation of the contents have been noted in a second investigation carried out one decade after the first one.


Assuntos
Cádmio/análise , Chumbo/análise , Mercúrio/análise , Água do Mar/análise , Poluentes Químicos da Água/análise , Argélia , Monitoramento Ambiental , Espectrofotometria Atômica
7.
Brain Behav Immun ; 14(3): 185-97, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10970679

RESUMO

Studies of pituitary-deficient dwarf mice show that in the absence of a normally functioning pituitary, thymus development is impaired. Treatment with growth hormone, prolactin, and thyroid hormones restores thymus development. Smaller thymus size in pituitary-deficient animals could be due to defective development of precursors, impaired precursor immigration, impaired thymocyte expansion, or development of a smaller epithelial/stromal compartment in the thymus of pituitary-deficient animals. Using a well-characterized amphibian model to study stem cell immigration into the thymus, we show here that hypophysectomy (hypx) of young tadpoles interferes with overall growth of the frogs and with the broad lymphocyte expansion that occurs after metamorphosis, but it does not interfere with the immigration of T cell precursors into an implanted thymus. Diploid host cells moving into a triploid thymus implant do so at the same rate and to the same extent in hypx hosts as they do in intact control hosts. Analysis of cell division in the implanted thymus populations shows a significantly greater proportion of cells arrested in the G(0)/G(1) phase and a significantly lower proportion of cells in the S phase and G(2) + M phase of the cell cycle in hypx hosts than in intact hosts. Thus, smaller thymus size in hypx hosts could be due to a slower rate of expansion of precursors that migrate there.


Assuntos
Envelhecimento/fisiologia , Animais Recém-Nascidos/fisiologia , Metamorfose Biológica/fisiologia , Hipófise/fisiologia , Linfócitos T/citologia , Xenopus laevis/fisiologia , Animais , Animais Recém-Nascidos/crescimento & desenvolvimento , Divisão Celular/fisiologia , Hipofisectomia , Linfócitos/citologia , Baço/citologia , Timo/citologia , Timo/crescimento & desenvolvimento , Fatores de Tempo , Xenopus laevis/crescimento & desenvolvimento
8.
Dermatology ; 185(4): 319-24, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1477435

RESUMO

Two cases and histological observations of erosive adenomatosis of the nipple are presented in detail, and the literature on the subject is reviewed. Erosive adenomatosis is a rare but clearly delineated pathology of the nipple and seems to be essentially benign. Careful clinical and histological examinations with complete investigation of the breast are required for the diagnosis. Nonmutilating curative surgery can be performed.


Assuntos
Neoplasias da Mama/patologia , Cistadenoma/patologia , Mamilos , Feminino , Humanos , Pessoa de Meia-Idade
9.
Dermatologica ; 159(2): 101-14, 1979.
Artigo em Francês | MEDLINE | ID: mdl-478049

RESUMO

A 46-year-old female, otherwise healthy, developed erythematous, pseudotumoral nodules, mainly on the hands; biopsies led to the diagnosis of Woringer-Kolopp disease. Anti-anergic chemotherapy with levamisole proved hazardous but, possibly, beneficial. Classification into benign localized, fatal generalized and intermediate disease is briefly commented upon. Differential diagnosis and tumor origin are discussed; while the Merkel cell hypothesis has been recently advanced strong analogies and slight discrepancies with mycosis fungoides advocate the T cell lymphoma theory.


Assuntos
Linfoma/patologia , Dermatopatias/patologia , Neoplasias Cutâneas/patologia , Diagnóstico Diferencial , Feminino , Humanos , Levamisol/uso terapêutico , Linfoma/ultraestrutura , Pessoa de Meia-Idade , Micose Fungoide/tratamento farmacológico , Micose Fungoide/patologia , Micose Fungoide/ultraestrutura , Pele/patologia , Dermatopatias/tratamento farmacológico , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/ultraestrutura
12.
Dermatologica ; 151(2): 113-24, 1975.
Artigo em Francês | MEDLINE | ID: mdl-174960

RESUMO

While in general agreement with previous searchers, the authors direct their attention at peculiar or unknown structures such as: a huge phagosome sometimes loaded with a paracristalline rod; an occasional set of parallel microtubules along the reservoir; eventual duplication of the blepharoplast and even of the flagellum. There appear to be some 90 microtubules in the hyaloplasm of tleishmania tropica.


Assuntos
Leishmaniose/patologia , Pele/ultraestrutura , Adulto , Humanos , Corpos de Inclusão/ultraestrutura , Leishmania/ultraestrutura , Masculino , Microtúbulos/ultraestrutura , Mitocôndrias/ultraestrutura , Fagócitos/ultraestrutura
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA