Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 140
Filtrar
2.
J Assist Reprod Genet ; 37(12): 3089-3094, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33113072

RESUMO

PURPOSE: This study aims to report a case of urgent fertility preservation in an oncological patient with collection of immature oocytes in the absence of ovarian stimulation that, through in vitro maturation (IVM), followed by ICSI and cryopreservation of zygotes resulted, 10 years later, in the live birth of a healthy baby. METHODS: In September 2008, our clinic performed IVM in a 32-year-old woman diagnosed with a ductal invasive carcinoma with positive estradiol receptors, negative progesterone receptors and positive human epidermal growth factor receptor 2. The retrieval of immature oocytes was performed in the absence of ovarian stimulation after a simple mastectomy and prior to any chemotherapy treatment. The compact cumulus-oocyte complexes (COCs) collected were placed in Lag medium for 2 h, followed by incubation in IVM medium, supplemented with heat inactivated patient serum, recombinant FSH, and recombinant LH. After 30 h in culture, cumulus cells were removed, the metaphase II oocytes were microinjected, and the zygotes obtained were cryopreserved. In 2017, the zygotes were thawed and cultured until day 3. One embryo was transferred and the other cryopreserved. RESULTS: Four compact COCs were collected and subjected to IVM. Two oocytes reached metaphase II and were microinjected. Two zygotes were obtained and were cryopreserved at the two pronuclear stage. Approximately 9 years later, the two zygotes were thawed and cultured until day 3. An embryo with 10 cells was transferred and implanted, resulting in the birth of a healthy baby. CONCLUSIONS: In cases where urgency to start adjuvant therapy requires immediate oocyte collection, IVM may be the only option to obtain fully competent mature oocytes allowing for effective preservation of the reproductive potential.


Assuntos
Neoplasias da Mama/complicações , Criopreservação/métodos , Preservação da Fertilidade/métodos , Técnicas de Maturação in Vitro de Oócitos/métodos , Infertilidade Feminina/terapia , Nascido Vivo , Zigoto/citologia , Adulto , Feminino , Humanos , Infertilidade Feminina/etiologia , Recuperação de Oócitos , Indução da Ovulação , Gravidez
3.
Adv Exp Med Biol ; 1219: 389-401, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32130710

RESUMO

Cancers are complex tissues composed by genetically altered cancer cells and stromal elements such as inflammatory/immune cells, fibroblasts, endothelial cells and pericytes, neuronal cells, and a non-cellular component, the extracellular matrix. The complex network of interactions and crosstalk established between cancer cells and the supportig cellular and non-cellular components of the microenvironment are of extreme importance for tumor initiation and progression, strongly impacting the course and the outcome of the disease. Therefore, a better understanding of the tumorigenic processes implies the combined study of the cancer cell and the biologic, chemical and mechanic constituents of the tumor microenvironment, as their concerted action plays a major role in the carcinogenic pathway and is a key determinant of the efficacy of anti-cancer treatments. The use of animal models (e.g. Mouse, Zebrafish and Drosophila) to study cancer has greatly impacted our understanding of the processes governing initiation, progression and metastasis and allowed the discovery and pre-clinical validation of novel cancer treatments as it allows to recreate tumor development in a more pathophysiologic environment.


Assuntos
Carcinogênese , Modelos Animais de Doenças , Neoplasias/metabolismo , Neoplasias/patologia , Microambiente Tumoral , Animais , Drosophila melanogaster , Camundongos , Peixe-Zebra
5.
Genet Mol Res ; 16(3)2017 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-28973737

RESUMO

Due to the nutritional content and commercial value of its seeds, Bertholletia excelsa is one of the most important species exploited in the Amazon region. The species is hermaphroditic, insect pollinated, and its seeds are dispersed by barochory and animals. Because the fruit set is dependent on natural pollinator activity, gene flow plays a key role in fruit production. However, to date, there have been no studies on pollen and seed flow in natural populations of B. excelsa. Herein, we used microsatellite loci and parentage analysis to investigate the spatial genetic structure (SGS), realized pollen and seed dispersal, and effective pollen dispersal for two B. excelsa populations in the Brazilian Amazon forest. Two plots were established in natural forests from which adults, juveniles, and seeds were sampled. Realized and effective pollen flow was greater than realized seed flow. The distance of realized pollen dispersal ranged from 36 to 2060 m, and the distance of realized seed dispersal ranged from 30 to 1742 m. Both pollen and seeds showed a dispersal pattern of isolation by distance, indicating a high frequency of mating among near-neighbor trees and seed dispersal near to mother trees. Both populations present SGS up to 175 m, which can be explained by isolation by distance pollen and seed dispersal patterns. Our results suggested that fragmentation of these forest populations may result in a significant decrease in gene flow, due to the isolation by distance pollen and seed dispersal patterns.


Assuntos
Bertholletia/genética , Pólen/genética , Dispersão de Sementes , Sementes/genética , Bertholletia/fisiologia , Florestas , Fluxo Gênico , Endogamia , Repetições de Microssatélites , Pólen/fisiologia , Isolamento Reprodutivo , Sementes/fisiologia
6.
Heredity (Edinb) ; 119(4): 237-244, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28745717

RESUMO

Fish species exhibit substantial variation in the degree of genetic differentiation between sex chromosome pairs, and therefore offer the opportunity to study the full range of sex chromosome evolution. We used restriction-site associated DNA sequencing (RAD-seq) to study the sex chromosomes of Characidium gomesi, a species with conspicuous heteromorphic ZW/ZZ sex chromosomes. We screened 9863 single-nucleotide polymorphisms (SNPs), corresponding to ~1 marker/100 kb distributed across the genome for sex-linked variation. With this data set, we identified 26 female-specific RAD loci, putatively located on the W chromosome, as well as 148 sex-associated SNPs showing significant differentiation (average FST=0.144) between males and females, and therefore in regions of more recent divergence between the Z and W chromosomes. In addition, we detected 25 RAD loci showing extreme heterozygote deficiency in females but which were in Hardy-Weinberg equilibrium in males, consistent with degeneration of the W chromosome and therefore female hemizygosity. We validated seven female-specific and two sex-associated markers in a larger sample of C. gomesi, of which three localised to the W chromosome, thereby providing useful markers for sexing wild samples. Validated markers were evaluated in other populations and species of the genus Characidium, this exploration suggesting a rapid turnover of W-specific repetitive elements. Together, our analyses point to a complex origin for the sex chromosome of C. gomesi and highlight the utility of RAD-seq for studying the composition and evolution of sex chromosomes systems in wild populations.


Assuntos
Caraciformes/genética , Evolução Molecular , Cromossomos Sexuais/genética , Animais , Sequência Conservada/genética , Feminino , Genoma , Masculino , Sequências Repetitivas de Ácido Nucleico/genética , Análise de Sequência de DNA
7.
Clin Nutr ; 34(5): 810-7, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25575640

RESUMO

BACKGROUND: Immunonutrition has been reported to improve the immune status of perioperative cancer patients, thereby reducing complications and length of hospital stay. AIM: This study aimed to assess whether immunonutrition enriched in arginine, EPA & DHA and nucleotides could impact the immune cells responses in head & neck and esophageal cancer patients treated by radiochemotherapy (RCT). METHODS: A double-blind clinical trial was carried out in 28 patients randomized into two groups, receiving either an immunomodulating enteral nutrition formula (IEN, n = 13, Impact(®), Nestlé) or an isoenergetic isonitrogenous standard enteral nutrition formula (SEN, n = 15) throughout RCT (5-7 weeks). After isolation from whole blood, immune cells metabolism and functions were assessed at the beginning (Db) and at the end (De) of RCT. RESULTS: Immunonutrition maintained CD4(+)/CD8(+) T-lymphocyte counts ratio and CD3 membrane expression between Db and De. Polymorphonuclear cells CD62L and CD15 densities and ROS production were increased in IEN patients. Peripheral blood mononuclear cells (PBMC) production of pro-inflammatory prostaglandin-E2 was stable in IEN patients and lower than in SEN patients at De. Genes coding for immune receptors, antioxidant enzymes and NADPH oxidase subunits were overexpressed in the PBMC of IEN vs SEN patients at De. CONCLUSION: Immunonutrition can enhance immune cell responses through the modulation of their phenotypes and functions. By modulating the gene expression of immune cells, immunonutrition could make it easier for the organism to adapt to the systemic inflammation and oxidative stress induced by RCT. CLINICAL TRIAL REGISTRATION: This clinical trial has been registered on ClinicalTrial.gov website: NCT00333099.


Assuntos
Neoplasias Esofágicas/tratamento farmacológico , Leucócitos Mononucleares/efeitos dos fármacos , Idoso , Antioxidantes/farmacologia , Arginina/administração & dosagem , Biomarcadores/sangue , Contagem de Células Sanguíneas , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/metabolismo , Quimiorradioterapia , Dinoprostona/metabolismo , Ácidos Docosa-Hexaenoicos/administração & dosagem , Método Duplo-Cego , Ácido Eicosapentaenoico/administração & dosagem , Nutrição Enteral/métodos , Feminino , Expressão Gênica , Humanos , Imunomodulação , Tempo de Internação , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , Estado Nutricional , Cuidados Pós-Operatórios , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio , Transcriptoma
9.
Mol Ecol Resour ; 13(3): 546-9, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23521844

RESUMO

This article documents the addition of 268 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Alburnoides bipunctatus, Chamaerops humilis, Chlidonias hybrida, Cyperus papyrus, Fusarium graminearum, Loxigilla barbadensis, Macrobrachium rosenbergii, Odontesthes bonariensis, Pelteobagrus vachelli, Posidonia oceanica, Potamotrygon motoro, Rhamdia quelen, Sarotherodon melanotheron heudelotii, Sibiraea angustata, Takifugu rubripes, Tarentola mauritanica, Trimmatostroma sp. and Wallago attu. These loci were cross-tested on the following species: Alburnoides fasciatus, Alburnoides kubanicus, Alburnoides maculatus, Alburnoides ohridanus, Alburnoides prespensis, Alburnoides rossicus, Alburnoides strymonicus, Alburnoides thessalicus, Alburnoides tzanevi, Carassius carassius, Fusarium asiaticum, Leucaspius delineatus, Loxigilla noctis dominica, Pelecus cultratus, Phoenix canariensis, Potamotrygon falkneri, Trachycarpus fortune and Vimba vimba.


Assuntos
Bases de Dados Genéticas/estatística & dados numéricos , Repetições de Microssatélites/genética , Primers do DNA/genética , Especificidade da Espécie
10.
Transpl Immunol ; 24(2): 100-6, 2011 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-21040785

RESUMO

The benefits of extracorporeal photochemotherapy (ECP; psoralen and UVA exposure of blood mononuclear cells) in graft-versus-host-disease (GVHD) are well-recognized, but the mechanisms of action remain elusive. As the metabolism of l-arginine in immune cells is known to play a role in immune tolerance, we investigated the effect of ECP on arginine metabolism, and the influence of extracellular l-arginine concentration on the response to ECP in cells from patients on therapy by ECP for a GVHD and healthy donors cultured before and after ECP in the presence of different concentrations of arginine (0, 50, 100, 200 and 1000 µmol/l). At baseline arginine was not metabolized through the same pathway in patients and donors. When cells were exposed to ECP, the production of ornithine but not NO° was enhanced, while mRNA of arginase 1 was up-regulated but not INOS. In GVHD patients, increasing arginine concentration resulted in down-regulation of IFNγ and TNFα mRNA expression, whereas IL10 was up-regulated especially at physiological plasma levels (between 0 and 100 µM). Overall, our study shows that ECP orients the metabolism of arginine toward the arginase pathway together with shifting the cytokine profile toward IL-10, providing new insights into the enigmatic mechanism of action of ECP.


Assuntos
Arginase/metabolismo , Arginina/metabolismo , Doença Enxerto-Hospedeiro/tratamento farmacológico , Doença Enxerto-Hospedeiro/enzimologia , Fotoferese , Adolescente , Adulto , Arginase/genética , Células Cultivadas , Criança , Indução Enzimática , Feminino , Doença Enxerto-Hospedeiro/imunologia , Humanos , Tolerância Imunológica , Interferon gama/genética , Interleucina-10/genética , Interleucina-10/metabolismo , Masculino , Pessoa de Meia-Idade , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Ornitina/biossíntese , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
11.
Anal Bioanal Chem ; 397(2): 841-9, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20225056

RESUMO

One degradation phenomenon that occurs in artworks is the formation of metal oxalates on their surfaces. In order to gain insight into the inclination of pigments to produce oxalates, nine pigments including Na, Ca, Fe, Pb and Cu cations were selected to react with oxalic acid solutions at different concentrations (1 M, 0.1 M, 0.01 M and 0.005 M). Micro-Raman spectroscopy was used to detect the different reaction products. Pigments containing calcium (calcite, gypsum and Volterra gypsum) showed a high tendency to form weddellite as well as whewellite, especially at high acidic concentrations; among copper-based pigments (malachite, azurite, verdigris), the formation of moolooite was observed for high concentrations of acid and down to the lowest concentration (0.005 M) in the case of verdigris. Lead oxalate was detected on lead white. No iron oxalates were observed for hematite; the formation of calcium oxalate crystals was observed instead. Ultramarine blue reacted to produce elemental sulfur. According to the results obtained, calcite and verdigris showed the highest reactivity in oxalic acid environments, resulting in a high tendency to form calcium and copper oxalates, even at very low acidic concentrations; this behavior seems to arise from the high solubilities of these pigments in acidic environments.

12.
Int J Biochem Cell Biol ; 42(1): 80-9, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19781661

RESUMO

Sialyl Lewis x and sialyl Lewis a expression depends on sialyltransferases and fucosyltransferases. In this study, we screened for major variations of sialyltransferases and fucosyltransferases involved in the synthesis and regulation of sialyl Lewis x and sialyl Lewis a epitopes in gastrointestinal carcinoma cells. Our results show that expression of ST3Gal IV in several gastrointestinal cell lines is correlated with the expression of sialyl Lewis x at the cell surface. ST3Gal IV overexpressed in the gastric MKN45 cell line, showed exclusive enzymatic activity towards glycoproteins containing terminal Galbeta1-4GlcNAc structure. On the other hand, when ST3Gal III was overexpressed in MKN45, an increase in the expression levels of both sialyl Lewis epitopes was observed. ST3Gal III and ST3Gal IV lead to de novo synthesis of sialyl Lewis x determinant on different molecular weight glycoproteins of MKN45 cells suggesting that each enzyme used different substrates within the available glycoproteome. The final glycosylation step in sialyl Lewis x and sialyl Lewis a biosynthesis in MKN45 cell line was shown to be associated to FUT5, which efficiently fucosylated sialyl Lewis precursors on glycoproteins. Moreover we demonstrate that the expression of sialyl Lewis epitopes in the MKN45 was induced by cell confluence, which can be regarded as a model to study altered glycosylation during tumour progression. This increase was observed together with an increase in mRNA levels of ST3GAL3, FUT5 and FUT6, and a decrease in FUT4 transcript levels in MKN45 confluent cells, suggesting a possible control at the transcriptional level.


Assuntos
Antígenos Glicosídicos Associados a Tumores/metabolismo , Fucosiltransferases/metabolismo , Oligossacarídeos/metabolismo , Sialiltransferases/metabolismo , Neoplasias Gástricas/enzimologia , Antígeno CA-19-9 , Contagem de Células , Extratos Celulares , Linhagem Celular Tumoral , Fucosiltransferases/genética , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Antígeno Sialil Lewis X , Sialiltransferases/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Transfecção , beta-Galactosídeo alfa-2,3-Sialiltransferase
13.
Rev Sci Instrum ; 80(7): 076109, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19655994

RESUMO

A small, potentially transportable prototype instrument capable of carrying out Raman, laser-induced breakdown (LIB), and laser-induced fluorescence (LIF) spectroscopy using a single pulsed laser source was developed for the analysis of cultural heritage objects. The purpose of this instrumentation is to perform fast and reliable analysis of surfaces with minimum damage to an object. For this purpose, a compact (51 x 203 x 76 mm) nanosecond Q-switched neodymium doped yttrium aluminum garnet laser (8 ns, 20 Hz, 0.01-115 mJ/pulse) was used as an irradiation source. The use of a nanosecond-gated detector sensitive between 180 and 900 nm allows the acquisition of elemental emissions in LIB spectroscopy and can also be employed for both LIF and time-resolved Raman spectroscopy. In this work, attention is focused on the description of the instrument and its optical components, and two examples of applications for the analysis of pigments and binding media used in works of art are presented.

14.
Endocr Relat Cancer ; 16(4): 1197-210, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19661131

RESUMO

Obesity is a risk factor for breast cancer development. A recent hypothesis suggests that the adipokines, adiponectin and leptin, are involved in breast cancer development. This prompted us to investigate the role of adiponectin and leptin in mammary carcinogenesis. Adiponectin receptors (AdipoR1 and AdipoR2) and leptin receptor (Ob-Rt, representing all the isoforms of Ob-R) proteins were detected by immunohistochemistry in in situ ductal carcinoma, invasive ductal malignancy, and healthy adjacent tissue. In addition, mRNA expression of adiponectin, AdipoR1, AdipoR2, leptin, Ob-Rt, and Ob-Rl (the long isoform of Ob-R) was observed in MCF-7 breast cancer cells. Interestingly, leptin mRNA expression was 34.7-fold higher than adiponectin mRNA expression in the MCF-7 cell line. Moreover, adiponectin (10 microg/ml) tended to decrease the mRNA expression of leptin (-36%) and Ob-Rl (-28%) and significantly decreased Ob-Rt mRNA level (-26%). In contrast, leptin treatment (1 microg/ml) significantly decreased AdipoR1 mRNA (-23%). Adiponectin treatment (10 microg/ml) inhibited the proliferation of MCF-7 cells, whereas leptin (1 microg/ml) stimulated the growth of cancer cells. In addition, adiponectin inhibited leptin-induced cell proliferation (both 1 microg/ml). Using microarray analysis, we found that adiponectin reduced the mRNA levels of genes involved in cell cycle regulation (mitogen-activated protein kinase 3 and ATM), apoptosis (BAG1, BAG3, and TP53), and potential diagnosis/prognosis markers (ACADS, CYP19A1, DEGS1, and EVL), whereas leptin induced progesterone receptor mRNA expression. In conclusion, the current study indicates an interaction of leptin- and adiponectin-signaling pathways in MCF-7 cancer cells whose proliferation is stimulated by leptin and suppressed by adiponectin.


Assuntos
Adiponectina/metabolismo , Neoplasias da Mama/metabolismo , Leptina/metabolismo , Receptores de Adiponectina/metabolismo , Receptores para Leptina/metabolismo , Adiponectina/genética , Apoptose , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Western Blotting , Mama/metabolismo , Mama/patologia , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/genética , Carcinoma Ductal de Mama/metabolismo , Carcinoma Ductal de Mama/patologia , Proliferação de Células , Feminino , Perfilação da Expressão Gênica , Humanos , Técnicas Imunoenzimáticas , Técnicas In Vitro , Leptina/genética , Invasividade Neoplásica , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Adiponectina/genética , Receptores para Leptina/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas
15.
J Clin Endocrinol Metab ; 94(8): 2864-71, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19435823

RESUMO

CONTEXT: Obesity in adolescents is increasingly prevalent and its impact on cardiovascular risk important to determine. Hormonal predictors of cardiovascular risk markers in obese adolescents are not known. OBJECTIVE: Our objective was to examine whether relative GH deficiency and cortisol excess are determinants of increased cardiovascular risk markers in obese teenage girls. DESIGN AND SETTING: A cross-sectional study was conducted at a clinical research center. STUDY PARTICIPANTS: Thirty girls (15 obese girls and 15 normal-weight controls) 12-18 years old matched for maturity and race. MAIN OUTCOME MEASURES: Inflammatory markers of cardiovascular risk including high-sensitivity C-reactive protein (hsCRP), TNF-alpha receptors 1 and 2, E-selectin, soluble intercellular adhesion molecule-1, and IL-6 were analyzed. Leptin, adiponectin, and 24-h urine free cortisol (UFC) were also measured. A GHRH-arginine stimulation test was performed. RESULTS: The hsCRP levels were higher in obese girls than controls (4.63 +/- 4.81 vs. 0.67 +/- 0.72 mg/liter; P = 0.002 after log conversion), as were other markers of cardiovascular risk. Eight of the 15 obese girls but no normal-weight girl had hsCRP higher than 3 mg/liter (P = 0.002). Body mass index sd score was higher than 4.0 in 87.5% of girls with hsCRP higher than 3 mg/liter and no girls with hsCRP less than 3 mg/liter. Girls with hsCRP higher than 3 mg/liter had higher UFC and lower peak GH compared with those with hsCRP less than 3 mg/liter. Peak GH was an important negative predictor of most markers of increased cardiovascular risk. In addition to peak GH, UFC and adiponectin independently predicted hsCRP. CONCLUSION: Relative GH deficiency and cortisol excess are significant contributors to increased levels of markers of cardiovascular risk in obese adolescent girls.


Assuntos
Doenças Cardiovasculares/etiologia , Hormônio do Crescimento Humano/deficiência , Hidrocortisona/fisiologia , Obesidade/metabolismo , Adolescente , Proteína C-Reativa/análise , Criança , Estudos Transversais , Selectina E/sangue , Feminino , Humanos , Hidrocortisona/urina , Fator de Crescimento Insulin-Like I/análise , Molécula 1 de Adesão Intercelular/sangue , Interleucina-6/sangue , Receptores Tipo II do Fator de Necrose Tumoral/sangue
16.
Nucleic Acids Res ; 37(8): 2419-33, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19295136

RESUMO

The discovery of microRNAs (miRNAs), almost 10 years ago, changed dramatically our perspective on eukaryotic gene expression regulation. However, the broad and important functions of these regulators are only now becoming apparent. The expansion of our catalogue of miRNA genes and the identification of the genes they regulate owe much to the development of sophisticated computational tools that have helped either to focus or interpret experimental assays. In this article, we review the methods for miRNA gene finding and target identification that have been proposed in the last few years. We identify some problems that current approaches have not yet been able to overcome and we offer some perspectives on the next generation of computational methods.


Assuntos
Biologia Computacional/métodos , MicroRNAs/genética , MicroRNAs/metabolismo , Interferência de RNA , RNA Mensageiro/química , Animais , Genes , MicroRNAs/biossíntese , RNA Mensageiro/metabolismo
17.
Anal Bioanal Chem ; 394(4): 1033-41, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19214480

RESUMO

A nanosecond pulsed laser setup has been optimized to perform laser-induced breakdown spectroscopy (LIBS) and pulsed Raman spectroscopy measurements in the field of cultural heritage. Three different samples of artistic/architectural interest with different typologies have been analyzed. The results from the two techniques allowed the identification of the materials used in their manufacture or contaminating them, probably coming from atmospheric pollution and biological activity. No sampling and sample preparation was required before the measurements, and no visual or structural damage was observed. Depth profiling using LIBS was performed in one of the samples, providing elemental information along the different layers composing the object and covering its surface. The quality of the results and the rather short time needed for the measurements and for switching between techniques confirmed the instrument's capabilities and specificity for dealing with objects of artistic or historical interest.


Assuntos
Arte , Lasers , Análise Espectral/métodos , Análise Espectral Raman/métodos
18.
Artigo em Inglês | MEDLINE | ID: mdl-19129003

RESUMO

Pulsed laser induced breakdown spectroscopy (LIBS) and Raman spectroscopy were performed using a novel laboratory setup employing the same Nd:YAG laser emission at 532 nm for the analysis of five commercially available pigments collectively known as "ultramarine blue", a sodium silicate material of either mineral origin or an artificially produced glass. LIBS and Raman spectroscopy have provided information regarding the elemental and molecular composition of the samples; additionally, an analytical protocol for the differentiation between natural (lapis lazuli) and artificial ultramarine blue pigments is proposed. In particular LIBS analysis has allowed the discrimination between pigments on the basis of peaks ascribed to calcium. The presence of calcite in the natural blue pigments has been confirmed following Raman spectroscopy in specific areas of the samples, and micro-Raman and optical microscopy have further corroborated the presence of calcite inclusions in the samples of natural origin. Finally multivariate analysis of Laser induced breakdown spectra using principal component analysis (PCA) further enhanced the differentiation between natural and artificial ultramarine blue pigments.


Assuntos
Silicatos de Alumínio/análise , Corantes/análise , Lasers , Análise Espectral Raman/instrumentação , Análise Espectral Raman/métodos , Desenho de Equipamento , Microscopia de Polarização , Análise de Componente Principal
19.
J Pathol ; 215(3): 308-16, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18498114

RESUMO

Helicobacter pylori (Hp) infects half the world's population and causes diverse gastric lesions, from gastritis to gastric cancer. Our aim was to evaluate the significance of secretor and Lewis status in infection and in vitro adherence by Hp expressing BabA adhesin. We enrolled 304 Hp-infected individuals from Northern Portugal. Gastric biopsies, blood and saliva were collected. Polymerase chain reaction (PCR) and immunofluorescence were used to detect BabA+ Hp in gastric biopsies. In vitro adherence by a BabA expressing Hp strain to gastric biopsies was performed. Secretor status was identified by Ulex, a lectin that recognizes secretor-dependent glycan structures in saliva and in gastric mucosa, and by Lewis(a/b) antibodies, and indirectly by identification of an inactivating mutation in the FUT2 gene (G428A). BabA status of infecting Hp was associated with CagA and VacAs1 (p < 0.05), intercellular localization of Hp (p < 0.01) and the presence of intestinal metaplasia (p < 0.05) and degenerative alterations (p < 0.005) in the biopsies. BabA was associated (p < 0.05) with Ulex staining of gastric biopsies and, although not significantly, to absence of homozygosity for FUT2 G428A inactivating polymorphism. In vitro Hp adherence was higher in cases wild-type or heterozygous for FUT2 G428A mutation (p < 0.0001), cases staining for Ulex (p < 0.0001) and a(-)b+ and a(-)b(-) secretor phenotypes (p < 0.001). In conclusion, BabA+ Hp infection/adhesion is secretor-dependent and associated with the severity of gastric lesions.


Assuntos
Adesinas Bacterianas/metabolismo , Dispepsia/microbiologia , Infecções por Helicobacter/sangue , Infecções por Helicobacter/microbiologia , Helicobacter pylori/patogenicidade , Antígenos do Grupo Sanguíneo de Lewis , Adesinas Bacterianas/genética , Aderência Bacteriana , Distribuição de Qui-Quadrado , Dispepsia/sangue , Imunofluorescência , Fucosiltransferases/genética , Fucosiltransferases/metabolismo , Mucosa Gástrica/microbiologia , Helicobacter pylori/química , Humanos , Masculino , Fenótipo , Polimorfismo Genético , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Saliva/imunologia , Coloração e Rotulagem , Galactosídeo 2-alfa-L-Fucosiltransferase
20.
J Pathol ; 215(4): 411-20, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18498120

RESUMO

Helicobacter pylori infection induces intestinal metaplasia of the stomach, a preneoplastic lesion associated with an increased risk for gastric cancer development. Intestinal metaplasia is induced by the intestine-specific transcription factor CDX2 but the mechanisms responsible for this ectopic expression have never been described. We hypothesized that the BMP/SMAD pathway has a role in CDX2 regulation, in this context, for the following reasons: (1) the BMP pathway is crucial for normal intestinal differentiation and (2) there is an influx of BMP2 and BMP4-producing cells to the stomach upon Helicobacter pylori infection. We evaluated the expression of key elements of the BMP pathway in human stomach specimens with IM. Growth factor treatments, with BMP2 and BMP4, were performed in cultured cells and a knock-down experiment of SMAD4 was done using RNAi. We showed overexpression in IM of BMP2/4, BMPR1A, and SMAD4 in 56% of IM foci, and pSMAD1/5/8 in 100% of IM foci as compared to adjacent mucosa. In vitro, treatment of AGS cells with BMP2 and BMP4 increased endogenous CDX2 expression as well as the intestinal differentiation markers MUC2 and LI-cadherin. On the other hand, SMAD4 knock-down led to decreased endogenous CDX2, MUC2, and LI-cadherin in AGS. Treatment of the SMAD4 knock-down cells had no influence on CDX2 expression as opposed to wild-type cells. A 9.3 kb CDX2 promoter could be transactivated by SMAD4 and SMAD1 in a cell-dependent manner. In conclusion, we identified for the first time that the BMP pathway is active in intestinal metaplasia and that BMP2 and BMP4 regulate CDX2 expression and promote intestinal differentiation through the canonical signal transducers.


Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Carcinoma/genética , Regulação Neoplásica da Expressão Gênica , Proteínas de Homeodomínio/genética , Neoplasias Gástricas/genética , Fator de Crescimento Transformador beta/metabolismo , Western Blotting/métodos , Proteína Morfogenética Óssea 2 , Proteína Morfogenética Óssea 4 , Proteínas Morfogenéticas Ósseas/genética , Proteínas Morfogenéticas Ósseas/farmacologia , Fator de Transcrição CDX2 , Carcinoma/metabolismo , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Proteínas de Homeodomínio/análise , Humanos , Imuno-Histoquímica , Interferência de RNA , RNA Interferente Pequeno/farmacologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Proteína Smad1/metabolismo , Proteína Smad4/genética , Proteína Smad4/metabolismo , Neoplasias Gástricas/metabolismo , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...