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1.
Front Psychol ; 13: 947507, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36438307

RESUMO

To date, there are no brief child self-report coping measures for the pandemic and other major societal events resulting in social or learning disruptions for children. Ignoring the voice of children can ultimately result in programs or services that fail to meet their needs. Thus, a child self-report measure called the 3Cs (Children's Crisis Coping) was developed and underwent pilot evaluation. This measure was designed in collaboration with key stakeholders using a Knowledge Translation-Integrated development framework. Some of the primary concerns that were relevant in the literature for the development of a pandemic coping measure included stress, worries, loneliness, and unpredictable school changes. The completed 4-item measure, grounded in these concerns, demonstrated good internal consistency reliability, as well as convergent validity with mental health and meaning mindset. A Second Wave Positive Psychology framework is presented concerning a spiritual concept called "meaning mindset" and it's association with positive societal crisis coping (i.e., pandemic coping in the present study).

2.
Int J Pharm ; 572: 118816, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31678527

RESUMO

Amorphous solid dispersion (ASD) is one of the most promising strategies for improving the solubility of active pharmaceutical ingredients (APIs) with low aqueous solubility. Solvent-based techniques such as electrospinning (ES), spray-drying (SD) and rotary evaporation (RE), have all previously been shown to be effective techniques for formulating ASDs. To date however, the effect of these processing techniques on the physicochemical properties and ASD homogeneity or "quality of ASD" produced remains largely unexplored. This work uses ibuprofen (IBU) as a model BCS class II API with two cellulosic excipients, HPMCAS and HPMCP-HP55 to produce ASDs by employing ES, SD and RE processing techniques. The physicochemical, morphological and dissolution properties of each sample were evaluated and the ASD forming strengths of each of the polymers were assessed using Differential Scanning Calorimetry (DSC). Principal |Component Analysis (PCA) of Raman spectra of crystalline and amorphous IBU was employed for qualitative analysis of ASD homogeneity and subsequent ASD stability during long-term storage. Results show that while ASD formation is predominantly dependent on API:excipient ratio, the ASD homogeneity is highly dependent on processing technique. Dissolution studies show that electrospun samples had the highest API release rate due to their fibrous morphology and higher specific surface area. However, these samples were the least homogenous of all ASDs produced thereby potentially influencing sample stability during long term storage. In addition, the higher melting point depression, higher Tg, and increased abundance of functional groups suitable for hydrogen bonding, show HPMCAS to be a significantly better ASD co-former when compared with HPMCP-HP55.


Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Química Farmacêutica , Ibuprofeno/administração & dosagem , Polímeros/química , Anti-Inflamatórios não Esteroides/química , Varredura Diferencial de Calorimetria , Composição de Medicamentos , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Excipientes/química , Ligação de Hidrogênio , Ibuprofeno/química , Metilcelulose/análogos & derivados , Metilcelulose/química , Solubilidade , Solventes/química
3.
Mol Pharm ; 15(11): 5327-5335, 2018 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-30259745

RESUMO

The Flory-Huggins (F-H) solubility equation has been widely used to describe the solubility of a small-molecule drug in a polymeric carrier and thus determine the design space available for formulating a stable amorphous solid dispersion. The F-H interaction parameter (χ) describes the thermodynamic properties of drug-polymer solutions and accounts for any enthalpic and entropic changes in solubility. Many studies have found that for a limited compositional range, χ varies proportionally to the inverse of the melting temperature of the drug. We explored this relationship using a highly sensitive DSC technique to detect remaining residual crystalline active pharmaceutical ingredients (APIs) following annealing of ball milled mixtures of crystalline itraconazole (ITZ) and either Soluplus or hydroxypropyl methylcellulose phthalate (HPMCP) at temperatures near the estimated solubility curve. Depending on the experimental approach taken, the measurement of drug-polymer solubility can be restricted to mixtures with a high proportion of drug, but in this study, solubility was experimentally determined for mixtures with API content as low as 10 wt %. Results suggest that the proposed linear relationship does not extend to compositions with smaller amounts of API, instead indicating that χ was both temperature- and composition-dependent for the systems studied. The feasibility of this technique to measure interactions in a ternary system containing itraconazole and both polymers was also determined; ITZ-HPMCP exhibited the most favorable values of χ, while ITZ-Soluplus and ITZ-Soluplus-HPMCP demonstrated similar interaction parameters.


Assuntos
Química Farmacêutica/métodos , Composição de Medicamentos/métodos , Preparações Farmacêuticas/química , Polímeros/química , Temperatura , Varredura Diferencial de Calorimetria/métodos , Cristalização , Estudos de Viabilidade , Solubilidade
4.
Mol Nutr Food Res ; 62(22): e1800411, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30192066

RESUMO

SCOPE: Inadequate maternal folate intake is associated with increased childhood acute lymphoblastic leukemia (ALL) risk. Folate provides methyl groups for DNA methylation, which is dramatically disrupted in ALL. Whether or not maternal folate (and related B-vitamin) intake during pregnancy may affect ALL risk via influencing DNA methylation is investigated. METHODS AND RESULTS: Genes in which methylation changes are reported both in response to folate status and in ALL are investigated. Folate-responsive genes (n = 526) are identified from mouse models of maternal folate depletion during pregnancy. Using published data, 2621 genes with persistently altered methylation in ALL are identified. Overall 25 overlapping genes are found, with the same directional methylation change in response to folate depletion and in ALL. Hypermethylation of a subset of genes (ASCL2, KCNA1, SH3GL3, SRD5A2) in ALL is confirmed by measuring 20 patient samples using pyrosequencing. In a nested cohort of cord blood samples (n = 148), SH3GL3 methylation is inversely related to maternal RBC folate concentrations (p = 0.008). Furthermore, ASCL2 methylation is inversely related to infant vitamin B12 levels. (p = 0.016). CONCLUSION: Findings demonstrate proof of concept for a plausible mechanism, i.e., variation in DNA methylation, by which low intake of folate, and related B-vitamins during pregnancy may influence ALL risk.


Assuntos
Metilação de DNA , Ácido Fólico/sangue , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Vitamina B 12/sangue , 3-Oxo-5-alfa-Esteroide 4-Desidrogenase/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Eritrócitos/metabolismo , Feminino , Ácido Fólico/administração & dosagem , Humanos , Lactente , Recém-Nascido , Canal de Potássio Kv1.1/genética , Masculino , Proteínas de Membrana/genética , Camundongos Endogâmicos C57BL , Mães , Gravidez
5.
Int J Pharm ; 544(1): 242-253, 2018 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-29689366

RESUMO

Downstream processing aspects of a stable form of amorphous itraconazole exhibiting enhanced dissolution properties were studied. Preparation of this ternary amorphous solid dispersion by either spray drying or hot melt extrusion led to significantly different powder processing properties. Particle size and morphology was analysed using scanning electron microscopy. Flow, compression, blending and dissolution were studied using rheometry, compaction simulation and a dissolution kit. The spray dried material exhibited poorer flow and reduced sensitivity to aeration relative to the milled extrudate. Good agreement was observed between differing forms of flow measurement, such as Flow Function, Relative flow function, Flow rate index, Aeration rate, the Hausner ratio and the Carr index. The stability index indicated that both powders were stable with respect to agglomeration, de-agglomeration and attrition. Tablet ability and compressibility studies showed that spray dried material could be compressed into stronger compacts than extruded material. Blending of the powders with low moisture, freely-flowing excipients was shown to influence both flow and compression. Porosity studies revealed that blending could influence the mechanism of densification in extrudate and blended extrudate formulations. Following blending, the powders were compressed into four 500 mg tablets, each containing a 100 mg dose of amorphous itraconazole. Dissolution studies revealed that the spray dried material released drug faster and more completely and that blending excipients could further influence the dissolution rate.


Assuntos
Antifúngicos/química , Composição de Medicamentos/métodos , Itraconazol/química , Dessecação/métodos , Liberação Controlada de Fármacos , Excipientes/química , Temperatura Alta , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Pós , Reologia , Comprimidos
6.
J Pharm Sci ; 107(5): 1372-1382, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29410037

RESUMO

The optimal design of amorphous solid dispersion formulations requires the use of excipients to maintain supersaturation and improve physical stability to ensure shelf-life stability and better absorption during intestinal transit, respectively. Blends of excipients (surfactants and polymers) are often used within pharmaceutical products to improve the oral delivery of Biopharmaceutical Classification System class II drugs. Therefore, in this study, a dissolution enhancer, poloxamer 407 (P407), was investigated to determine its effect on the dissolution properties and on the amorphous nature of the active pharmaceutical ingredient contained in the formulation. Phase solubility studies of indomethacin (INM) in aqueous solutions of P407 and poly(vinylpyrrolidone-vinyl acetate copolymer) showed an increase in the kinetic solubility of INM compared with the pure drug at 37°C with a Ka value of 0.041 µg/mL. The solid dispersions showed a higher dissolution rate when compared to pure and amorphous drugs when performed in pH buffer 1.2 with a kinetic solubility of 21 µg/mL. The stability data showed that the amorphous drug in solid solutions with poly(vinylpyrrolidone-vinyl acetate copolymer) and P407 remained amorphous, and the %P407 loading had no effect on the amorphous stability of INM. This study concluded that the amorphous solid dispersion contributed to the increased solubility of INM.


Assuntos
Anti-Inflamatórios não Esteroides/química , Compostos de Epóxi/química , Óxido de Etileno/química , Excipientes/química , Indometacina/química , Poloxâmero/química , Povidona/análogos & derivados , Cristalização , Estabilidade de Medicamentos , Transição de Fase , Povidona/química , Solubilidade , Tensoativos/química
7.
Hum Mol Genet ; 27(4): 742-756, 2018 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-29309628

RESUMO

Genome-wide association studies of birth weight have focused on fetal genetics, whereas relatively little is known about the role of maternal genetic variation. We aimed to identify maternal genetic variants associated with birth weight that could highlight potentially relevant maternal determinants of fetal growth. We meta-analysed data on up to 8.7 million SNPs in up to 86 577 women of European descent from the Early Growth Genetics (EGG) Consortium and the UK Biobank. We used structural equation modelling (SEM) and analyses of mother-child pairs to quantify the separate maternal and fetal genetic effects. Maternal SNPs at 10 loci (MTNR1B, HMGA2, SH2B3, KCNAB1, L3MBTL3, GCK, EBF1, TCF7L2, ACTL9, CYP3A7) were associated with offspring birth weight at P < 5 × 10-8. In SEM analyses, at least 7 of the 10 associations were consistent with effects of the maternal genotype acting via the intrauterine environment, rather than via effects of shared alleles with the fetus. Variants, or correlated proxies, at many of the loci had been previously associated with adult traits, including fasting glucose (MTNR1B, GCK and TCF7L2) and sex hormone levels (CYP3A7), and one (EBF1) with gestational duration. The identified associations indicate that genetic effects on maternal glucose, cytochrome P450 activity and gestational duration, and potentially on maternal blood pressure and immune function, are relevant for fetal growth. Further characterization of these associations in mechanistic and causal analyses will enhance understanding of the potentially modifiable maternal determinants of fetal growth, with the goal of reducing the morbidity and mortality associated with low and high birth weights.


Assuntos
Peso ao Nascer/genética , Estudo de Associação Genômica Ampla/métodos , Polimorfismo de Nucleotídeo Único/genética , Actinas/genética , Proteínas Adaptadoras de Transdução de Sinal , Alelos , Peso ao Nascer/fisiologia , Citocromo P-450 CYP3A/genética , Proteínas de Ligação a DNA/genética , Feminino , Variação Genética/genética , Genótipo , Quinases do Centro Germinativo , Idade Gestacional , Proteína HMGA2/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Canal de Potássio Kv1.3/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas/genética , Receptor MT2 de Melatonina/genética , Transativadores/genética , Proteína 2 Semelhante ao Fator 7 de Transcrição/genética
8.
Int J Pharm ; 532(1): 603-611, 2017 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-28923766

RESUMO

The aim of this study was to evaluate a novel combination of hydroxypropyl methylcellulose phthalate (HPMCP-HP-50) and Soluplus® polymers for enhanced physicochemical stability and solubility of the produced amorphous solid dispersions (ASDs). This was achieved using hot melt extrusion (HME) to convert the crystalline active pharmaceutical ingredient (API) into a more soluble amorphous form within the ternary systems. Itraconazole (ITZ), a Biopharmaceutics Classification System class II (BCS II) API, was selected as the model drug. The ASDs were characterized by Powder X-Ray diffraction (PXRD), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Fourier Transform Infrared (FTIR) spectroscopy, Solid State Nuclear Magnetic Resonance (ssNMR) and dissolution studies. The data showed that the ASDs were physically and chemically stable at 20°C and 50% RH over 12 months. PXRD results indicated that the ITZ in the ASDs was in the amorphous state and no recrystallization occurred. DSC scans confirmed that each formulation exhibited a single intermediate glass transition (Tg), around 96.4°C, indicating that ITZ was completely miscible in the polymeric blends of HPMCP and Soluplus® at up to 30% (w/w) drug loading and that the two polymers were miscible with each other in the presence of ITZ. The FTIR analysis indicated the formation of strong hydrogen bonding between ITZ, HPMCP and Soluplus®. The dissolution end-point of the ASDs was determined to be approximately 10 times greater than that of the crystalline ITZ.


Assuntos
Composição de Medicamentos , Itraconazol/química , Metilcelulose/análogos & derivados , Polietilenoglicóis/química , Polivinil/química , Química Farmacêutica , Temperatura Alta , Metilcelulose/química , Solubilidade
9.
Eur J Pharm Biopharm ; 119: 36-46, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28559112

RESUMO

Piracetam was investigated as a model API which is known to exhibit a number of different polymorphic forms. It is freely soluble in water so the possibility exists for polymorphic transformations to occur during wet granulation. Analysis of the polymorphic form present during lab-scale wet granulation, using water as a granulation liquid, was studied with powder X-ray diffraction and Raman spectroscopy as off-line and inline analysis tools respectively. Different excipients with a range of hydrophilicities, aqueous solubilities and molecular weights were investigated to examine their influence on these solution-mediated polymorphic transitions and experimental results were rationalised using molecular modelling. Our results indicated that as an increasing amount of water was added to the as-received piracetam FIII, a greater amount of the API dissolved which recrystallised upon drying to the metastable FII(6.403) via a monohydrate intermediary. Molecular level analysis revealed that the observed preferential transformation of monohydrate to FII is linked with a greater structural similarity between the monohydrate and FII polymorph in comparison to FIII. The application of Raman spectroscopy as a process analytical technology (PAT) tool to monitor the granulation process for the production of the monohydrate intermediate as a precursor to the undesirable metastable form was demonstrated.


Assuntos
Química Farmacêutica/métodos , Piracetam/análise , Piracetam/química , Fármacos Neuroprotetores/análise , Fármacos Neuroprotetores/química , Análise Espectral Raman/métodos , Difração de Raios X/métodos
10.
Int J Pharm ; 519(1-2): 365-372, 2017 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-28131850

RESUMO

A range of 17 ternary formulations of itraconazole (ITZ), HPMCP and Soluplus have been manufactured using spray drying. These amorphous solid dispersions (ASDs) were very stable against crystallisation and ITZ was found to be amorphous in all formulations after one year at 40°C/75% RH. A number of solid state analytical techniques including PXRD, DSC, small angle X-ray scattering, FTIR and solid state NMR were used to characterise the physicochemical properties of the ASDs following processing and storage and to assess any interactions between components. Microtrac laser scattering analysis revealed a relationship between polymer levels and particle size distribution (PSD). Dissolution studies indicated that higher Soluplus content in the formulation resulted in higher concentrations of ITZ in acidic media.


Assuntos
Itraconazol/química , Polietilenoglicóis/química , Polivinil/química , Varredura Diferencial de Calorimetria/métodos , Química Farmacêutica/métodos , Cristalização/métodos , Composição de Medicamentos/métodos , Excipientes/química , Tamanho da Partícula , Polímeros/química , Solubilidade , Difração de Raios X/métodos
11.
Mol Pharm ; 12(5): 1377-90, 2015 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-25730138

RESUMO

The formulation of BCS Class II drugs as amorphous solid dispersions has been shown to provide advantages with respect to improving the aqueous solubility of these compounds. While hot melt extrusion (HME) and spray drying (SD) are among the most common methods for the production of amorphous solid dispersions (ASDs), the high temperatures often required for HME can restrict the processing of thermally labile drugs, while the use of toxic organic solvents during SD can impact on end-product toxicity. In this study, we investigated the potential of supercritical fluid impregnation (SFI) using carbon dioxide as an alternative process for ASD production of a model poorly water-soluble drug, indomethacin (INM). In doing so, we produced ASDs without the use of organic solvents and at temperatures considerably lower than those required for HME. Previous studies have concentrated on the characterization of ASDs produced using HME or SFI but have not considered both processes together. Dispersions were manufactured using two different polymers, Soluplus and polyvinylpyrrolidone K15 using both SFI and HME and characterized for drug morphology, homogeneity, presence of drug-polymer interactions, glass transition temperature, amorphous stability of the drug within the formulation, and nonsink drug release to measure the ability of each formulation to create a supersaturated drug solution. Fully amorphous dispersions were successfully produced at 50% w/w drug loading using HME and 30% w/w drug loading using SFI. For both polymers, formulations containing 50% w/w INM, manufactured via SFI, contained the drug in the γ-crystalline form. Interestingly, there were lower levels of crystallinity in PVP dispersions relative to SOL. FTIR was used to probe for the presence of drug-polymer interactions within both polymer systems. For PVP systems, the nature of these interactions depended upon processing method; however, for Soluplus formulations this was not the case. The area under the dissolution curve (AUC) was used as a measure of the time during which a supersaturated concentration could be maintained, and for all systems, SFI formulations performed better than similar HME formulations.


Assuntos
Dióxido de Carbono/química , Química Farmacêutica/métodos , Polímeros/química , Composição de Medicamentos , Indometacina/química , Polietilenoglicóis/química , Polivinil/química , Povidona/química , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier
12.
Pharm Res ; 32(1): 167-79, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25074468

RESUMO

PURPOSE: Amorphous drug-polymer solid dispersions have been found to result in improved drug dissolution rates when compared to their crystalline counterparts. However, when the drug exists in the amorphous form it will possess a higher Gibb's free energy than its associated crystalline state and can recrystallize. Drug-polymer phase diagrams constructed through the application of the Flory Huggins (F-H) theory contain a wealth of information regarding thermodynamic and kinetic stability of the amorphous drug-polymer system. This study was aimed to evaluate the effects of various experimental conditions on the solubility and miscibility detections of drug-polymer binary system. METHODS: Felodipine (FD)-Polyvinylpyrrolidone (PVP) K15 (PVPK15) and FD-Polyvinylpyrrolidone/vinyl acetate (PVP/VA64) were the selected systems for this research. Physical mixtures with different drug loadings were mixed and ball milled. These samples were then processed using Differential Scanning Calorimetry (DSC) and measurements of melting point (Tend) and glass transition (Tg) were detected using heating rates of 0.5, 1.0 and 5.0°C/min. RESULTS: The melting point depression data was then used to calculate the F-H interaction parameter (χ) and extrapolated to lower temperatures to complete the liquid-solid transition curves. The theoretical binodal and spinodal curves were also constructed which were used to identify regions within the phase diagram. The effects of polymer selection, DSC heating rate, time above parent polymer Tg and polymer molecular weight were investigated by identifying amorphous drug miscibility limits at pharmaceutically relevant temperatures. CONCLUSION: The potential implications of these findings when applied to a non-ambient processing method such as Hot Melt Extrusion (HME) are also discussed.


Assuntos
Química Farmacêutica , Felodipino/química , Transição de Fase , Pirrolidinas/química , Compostos de Vinila/química , Varredura Diferencial de Calorimetria , Cristalização , Estabilidade de Medicamentos , Cinética , Peso Molecular , Termodinâmica , Temperatura de Transição
13.
PLoS One ; 8(10): e76506, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24098518

RESUMO

This study examines the relationship between common genetic variation within DNA methyltransferase genes and inter-individual variation in DNA methylation. Eleven polymorphisms spanning DNMT1 and DNMT3B were genotyped. Global and gene specific (IGF2, IGFBP3, ZNT5) DNA methylation was quantified by LUMA and bisulfite Pyrosequencing assays, respectively, in neonatal cord blood and in maternal peripheral blood. Associations between maternal genotype and maternal methylation (n (≈) 333), neonatal genotype and neonatal methylation (n (≈) 454), and maternal genotype and neonatal methylation (n (≈) 137) were assessed. The findings of this study provide some support to the hypothesis that genetic variation in DNA methylating enzymes influence DNA methylation at global and gene-specific levels; however observations were not robust to correction for multiple testing. More comprehensive analysis of the influence of genetic variation on global and site specific DNA methylation is warranted.


Assuntos
DNA (Citosina-5-)-Metiltransferases/genética , Metilação de DNA , Genótipo , Adulto , Proteínas de Transporte de Cátions/genética , Ilhas de CpG , DNA (Citosina-5-)-Metiltransferase 1 , Feminino , Loci Gênicos , Humanos , Recém-Nascido , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Fator de Crescimento Insulin-Like II/genética , Desequilíbrio de Ligação , Polimorfismo de Nucleotídeo Único , Gravidez , DNA Metiltransferase 3B
14.
Hum Mol Genet ; 21(24): 5344-58, 2012 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-22956269

RESUMO

Maternal smoking during pregnancy is associated with low birth weight. Common variation at rs1051730 is robustly associated with smoking quantity and was recently shown to influence smoking cessation during pregnancy, but its influence on birth weight is not clear. We aimed to investigate the association between this variant and birth weight of term, singleton offspring in a well-powered meta-analysis. We stratified 26 241 European origin study participants by smoking status (women who smoked during pregnancy versus women who did not smoke during pregnancy) and, in each stratum, analysed the association between maternal rs1051730 genotype and offspring birth weight. There was evidence of interaction between genotype and smoking (P = 0.007). In women who smoked during pregnancy, each additional smoking-related T-allele was associated with a 20 g [95% confidence interval (95% CI): 4-36 g] lower birth weight (P = 0.014). However, in women who did not smoke during pregnancy, the effect size estimate was 5 g per T-allele (95% CI: -4 to 14 g; P = 0.268). To conclude, smoking status during pregnancy modifies the association between maternal rs1051730 genotype and offspring birth weight. This strengthens the evidence that smoking during pregnancy is causally related to lower offspring birth weight and suggests that population interventions that effectively reduce smoking in pregnant women would result in a reduced prevalence of low birth weight.


Assuntos
Peso ao Nascer/genética , Variação Genética/genética , Receptores Nicotínicos/genética , Fumar/efeitos adversos , Feminino , Predisposição Genética para Doença/genética , Humanos , Lactente , Proteínas do Tecido Nervoso/genética , Gravidez
15.
PLoS One ; 7(3): e33290, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22479380

RESUMO

Inter-individual variation in patterns of DNA methylation at birth can be explained by the influence of environmental, genetic and stochastic factors. This study investigates the genetic and non-genetic determinants of variation in DNA methylation in human infants. Given its central role in provision of methyl groups for DNA methylation, this study focuses on aspects of folate metabolism. Global (LUMA) and gene specific (IGF2, ZNT5, IGFBP3) DNA methylation were quantified in 430 infants by Pyrosequencing®. Seven polymorphisms in 6 genes (MTHFR, MTRR, FOLH1, CßS, RFC1, SHMT) involved in folate absorption and metabolism were analysed in DNA from both infants and mothers. Red blood cell folate and serum vitamin B(12) concentrations were measured as indices of vitamin status. Relationships between DNA methylation patterns and several covariates viz. sex, gestation length, maternal and infant red cell folate, maternal and infant serum vitamin B(12), maternal age, smoking and genotype were tested. Length of gestation correlated positively with IGF2 methylation (rho = 0.11, p = 0.032) and inversely with ZNT5 methylation (rho = -0.13, p = 0.017). Methylation of the IGFBP3 locus correlated inversely with infant vitamin B(12) concentration (rho = -0.16, p = 0.007), whilst global DNA methylation correlated inversely with maternal vitamin B(12) concentrations (rho = 0.18, p = 0.044). Analysis of common genetic variants in folate pathway genes highlighted several associations including infant MTRR 66G>A genotype with DNA methylation (χ(2) = 8.82, p = 0.003) and maternal MTHFR 677C>T genotype with IGF2 methylation (χ(2) = 2.77, p = 0.006). These data support the hypothesis that both environmental and genetic factors involved in one-carbon metabolism influence DNA methylation in infants. Specifically, the findings highlight the importance of vitamin B(12) status, infant MTRR genotype and maternal MTHFR genotype, all of which may influence the supply of methyl groups for DNA methylation. In addition, gestational length appears to be an important determinant of infant DNA methylation patterns.


Assuntos
Metilação de DNA , Ácido Fólico/sangue , Polimorfismo Genético , Vitamina B 12/sangue , Adulto , Proteínas de Transporte de Cátions/genética , Ilhas de CpG/genética , Feminino , Ferredoxina-NADP Redutase/genética , Ferredoxina-NADP Redutase/metabolismo , Ácido Fólico/metabolismo , Frequência do Gene , Genótipo , Idade Gestacional , Humanos , Lactente , Recém-Nascido , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Fator de Crescimento Insulin-Like II/genética , Modelos Lineares , Masculino , Idade Materna , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Análise Multivariada , Reação em Cadeia da Polimerase , Gravidez , Vitamina B 12/metabolismo , Adulto Jovem
16.
Int J Epidemiol ; 41(1): 210-7, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22422454

RESUMO

BACKGROUND: Patterns of DNA methylation change with age and these changes are believed to be associated with the development of common complex diseases. The hypothesis that Long Interspersed Nucleotide Element 1 (LINE-1) DNA methylation (an index of global DNA methylation) is associated with biomarkers of metabolic health was investigated in this study. METHODS: Global LINE-1 DNA methylation was quantified by pyrosequencing in blood-derived DNA samples from 228 individuals, aged 49-51 years, from the Newcastle Thousand Families Study (NTFS). Associations between log-transformed LINE-1 DNA methylation levels and anthropometric and blood biochemical measurements, including triglycerides, total cholesterol, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, fasting glucose and insulin secretion and resistance were examined. RESULTS: Linear regression, after adjustment for sex, demonstrated positive associations between log-transformed LINE-1 DNA methylation and fasting glucose {coefficient 2.80 [95% confidence interval (CI) 0.39-5.22]}, total cholesterol [4.76 (95% CI 1.43-8.10)], triglycerides [3.83 (95% CI 1.30-6.37)] and LDL-cholesterol [5.38 (95% CI 2.12-8.64)] concentrations. A negative association was observed between log-transformed LINE-1 methylation and both HDL cholesterol concentration [-1.43 (95% CI -2.38 to -0.48)] and HDL:LDL ratio [-1.06 (95% CI -1.76 to -0.36)]. These coefficients reflect the millimoles per litre change in biochemical measurements per unit increase in log-transformed LINE-1 methylation. CONCLUSIONS: These novel associations between global LINE-1 DNA methylation and blood glycaemic and lipid profiles highlight a potential role for epigenetic biomarkers as predictors of metabolic disease and may be relevant to future diagnosis, prevention and treatment of this group of disorders. Further work is required to establish the role of confounding and reverse causation in the observed associations.


Assuntos
Glicemia , Metilação de DNA , Lipídeos/sangue , Elementos Nucleotídeos Longos e Dispersos/genética , Biomarcadores/sangue , Epigênese Genética , Feminino , Humanos , Masculino , Doenças Metabólicas/genética , Pessoa de Meia-Idade
17.
Gene ; 499(1): 99-107, 2012 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-22425646

RESUMO

There is considerable interest in defining the relationship between epigenetic variation and the risk of common complex diseases. Strategies which assist in the prioritisation of target loci that have the potential to be epigenetically regulated might provide a useful approach in identifying concrete examples of epigenotype-phenotype associations. Focusing on the postulated role of epigenetic factors in the aetiopathogenesis of obesity this report outlines an approach utilising gene expression data and a suite of bioinformatic tools to prioritise a list of target candidate genes for more detailed experimental scrutiny. Gene expression microarrays were performed using peripheral blood RNA from children aged 11-13years selected from the Newcastle Preterm Birth Growth Study which were grouped by body mass index (BMI). Genes showing ≥2.0 fold differential expression between low and high BMI groups were selected for in silico analysis. Several bioinformatic tools were used for each following step; 1) a literature search was carried out to identify whether the differentially expressed genes were associated with adiposity phenotypes. Of those obesity-candidate genes, putative epigenetically regulated promoters were identified by 2) defining the promoter regions, 3) then by selecting promoters with a CpG island (CGI), 4) and then by identifying any transcription factor binding modules covering CpG sites within the CGI. This bioinformatic processing culminated in the identification of a short list of target obesity-candidate genes putatively regulated by DNA methylation which can be taken forward for experimental analysis. The proposed workflow provides a flexible, versatile and low cost methodology for target gene prioritisation that is applicable to multiple species and disease contexts.


Assuntos
Biologia Computacional , Epigênese Genética/fisiologia , Loci Gênicos/genética , Obesidade/genética , Adolescente , Criança , Estudos de Coortes , Biologia Computacional/métodos , Metilação de DNA , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Predisposição Genética para Doença , Humanos , Masculino , Análise em Microsséries , Especificidade por Substrato/genética
18.
Arthritis Res Ther ; 14(1): R30, 2012 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-22314025

RESUMO

INTRODUCTION: At present, there is no reliable tool for predicting disease outcome in patients with rheumatoid arthritis (RA). We previously demonstrated an association between specific baseline biomarkers/clinical measures including matrix metalloproteinase-3 (MMP-3) and 2-year radiographic progression in patients with RA. This study further evaluates the predictive capability of these baseline variables with outcome extended over 8-years. METHODS: Fifty-eight of the original cohort (n = 118) had radiographic progression from baseline to mean 8.2-years determined using the van der Heijde modified Sharp method. The contribution of each predictor variable towards radiographic progression was assessed with univariate and multivariate analyses. RESULTS: Traditional factors (including erythrocyte sedimentation rate, C-reactive protein, anti-cyclic citrullinated peptide (anti-CCP), and rheumatoid factor) and biomarkers of tissue destruction (including MMP-3, C-telopeptide of type II collagen, cartilage oligomeric matrix protein, and tissue inhibitor of metalloproteinase 1) measured at baseline were associated with radiographic progression at endpoint. Multivariate logistic regression identified anti-CCP seropositivity [OR 9.29, 95%CI: 2.29-37.64], baseline elevated MMP-3 [OR 8.25, 95%CI: 2.54-26.78] and baseline radiographic damage [OR 5.83, 95%CI: 1.88-18.10] as the strongest independent predictors of radiographic progression. A model incorporating these variables had a predictive accuracy of 0.87, assessed using the area under the receiver operating characteristic curve. CONCLUSION: In our cohort with onset of RA symptoms < 2-years, multivariate analysis identified anti-CCP status and baseline MMP-3 as the strongest independent predictors of radiographic disease outcome at 8.2-years. This finding suggests determination of baseline MMP-3, in conjunction with traditional serologic markers, may provide additional prognostic information for patients with RA. Furthermore, these findings highlight the importance of continued research into a broad range of biomarkers as potential predictors of joint damage.


Assuntos
Artrite Reumatoide/sangue , Artrite Reumatoide/diagnóstico , Biomarcadores/sangue , Metaloproteinase 3 da Matriz/sangue , Adulto , Idoso , Artrite Reumatoide/diagnóstico por imagem , Progressão da Doença , Feminino , Seguimentos , Humanos , Modelos Logísticos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Observação , Valor Preditivo dos Testes , Prognóstico , Radiografia , Fatores de Tempo
19.
Man Ther ; 17(1): 39-46, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21955672

RESUMO

OBJECTIVE: This study aimed to design and pilot a questionnaire to survey the use of ultrasound imaging (USI) by physiotherapists in the United Kingdom (UK), the type and content of ultrasound training physiotherapists using USI had undertaken and their perceived future training needs. BACKGROUND: The use of USI by physiotherapists is becoming increasingly common but is highly operator dependent and there are safety and professional issues regarding use in physiotherapy practice. Currently there are no specific training guidelines relating to physiotherapists using USI. METHODS: A questionnaire was developed, based on research literature and guidelines. Twelve experts in USI commented on the content and design. The electronic on-line questionnaire was piloted on groups that were likely to be users of USI. RESULTS: Forty-six respondents completed the questionnaire. Results indicated that USI is used predominantly for biofeedback and there are many unmet training needs. Respondents reported a mismatch between techniques for which they had received training and those that they used in practice and indicated a more structured training framework is required. CONCLUSIONS: The development and piloting of the questionnaire provides a starting point for a more extensive evaluation of how USI is being used, the training needs of physiotherapists and benefits as a biofeedback tool. Refinement is needed and replication in a larger sample. Results could assist the development of a structured formal training framework encompassing key skills.


Assuntos
Competência Clínica , Fisioterapeutas/educação , Modalidades de Fisioterapia/educação , Ultrassonografia/estatística & dados numéricos , Estudos Transversais , Diagnóstico por Imagem/métodos , Educação Profissionalizante , Feminino , Humanos , Masculino , Projetos Piloto , Vigilância da População , Inquéritos e Questionários , Reino Unido
20.
Diabetes ; 61(2): 391-400, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22190649

RESUMO

Rapid postnatal growth is associated with increased risk of childhood adiposity. The aim of this study was to establish whether this pathway is mediated by altered DNA methylation and gene expression. Two distinct cohorts, one preterm (n=121) and one term born (n=6,990), were studied. Exploratory analyses were performed using microarrays to identify differentially expressed genes in whole blood from children defined as "slow" (n=10) compared with "rapid" (n=10) postnatal (term to 12 weeks corrected age) growers. Methylation within the identified TACSTD2 gene was measured in both cohorts, and rs61779296 genotype was determined by Pyrosequencing or imputation and analyzed in relation to body composition at 9-15 years of age. In cohort 1, TACSTD2 expression was inversely correlated with methylation (P=0.016), and both measures were associated with fat mass (expression, P=0.049; methylation, P=0.037). Although associated with gene expression (cohort 1, P=0.008) and methylation (cohort 1, P=2.98×10(-11); cohort 2, P=3.43×10(-15)), rs61779296 was not associated with postnatal growth or fat mass in either cohort following multiple regression analysis. Hence, the lack of association between fat mass and a methylation proxy SNP suggests that reverse causation or confounding may explain the initial association between fat mass and gene regulation. Noncausal methylation patterns may still be useful predictors of later adiposity.


Assuntos
Adiposidade , Antígenos de Neoplasias/genética , Composição Corporal , Moléculas de Adesão Celular/genética , Desenvolvimento Infantil , Metilação de DNA , Adolescente , Peso Corporal , Criança , Estudos de Coortes , Feminino , Perfilação da Expressão Gênica , Genótipo , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Masculino , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas
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