30 research outputs found

    Determination of the primary structure and carboxyl pKAs of heparin-derived oligosaccharides by band-selective homonuclear-decoupled two-dimensional 1H NMR

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    Determination of the structure of heparin-derived oligosaccharides by 1H NMR is challenging because resonances for all but the anomeric protons cover less than 2 ppm. By taking advantage of increased dispersion of resonances for the anomeric H1 protons at low pD and the superior resolution of band-selective, homonuclear-decoupled (BASHD) two-dimensional 1H NMR, the primary structure of the heparin-derived octasaccharide ∆UA(2S)-[(1 → 4)-GlcNS(6S)-(1 → 4)-IdoA(2S)-]3-(1 → 4)-GlcNS(6S) has been determined, where ∆UA(2S) is 2-O-sulfated ∆4,5-unsaturated uronic acid, GlcNS(6S) is 6-O-sulfated, N-sulfated β-d-glucosamine and IdoA(2S) is 2-O-sulfated α-l-iduronic acid. The spectrum was assigned, and the sites of N- and O-sulfation and the conformation of each uronic acid residue were established, with chemical shift data obtained from BASHD-TOCSY spectra, while the sequence of the monosaccharide residues in the octasaccharide was determined from inter-residue NOEs in BASHD-NOESY spectra. Acid dissociation constants were determined for each carboxylic acid group of the octasaccharide, as well as for related tetra- and hexasaccharides, from chemical shift–pD titration curves. Chemical shift–pD titration curves were obtained for each carboxylic acid group from sub-spectra taken from BASHD-TOCSY spectra that were measured as a function of pD. The pKAs of the carboxylic acid groups of the ∆UA(2S) residues are less than those of the IdoA(2S) residues, and the pKAs of the carboxylic acid groups of the IdoA(2S) residues for a given oligosaccharide are similar in magnitude. Relative acidities of the carboxylic acid groups of each oligosaccharide were calculated from chemical shift data by a pH-independent method

    Milk feeding, solid feeding, and obesity risk:a review of the relationships between early life feeding practices and later adiposity

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    Childhood obesity is a major health issue with associated ill-health consequences during childhood and into later adolescence and adulthood. Given that eating behaviors are formed during early childhood, it is important to evaluate the relationships between early life feeding practices and later child adiposity. This review describes and evaluates recent literature exploring associations between child weight and the mode of milk feeding, the age of introducing solid foods and caregivers’ solid feeding practices. There are many inconsistencies in the literature linking early life feeding to later obesity risk and discrepancies may be related to inconsistent definitions, or a lack of control for confounding variables. This review summarizes the literature in this area and identifies the need for large scale longitudinal studies to effectively explore how early life feeding experiences may interact with each other and with nutritional provision during later childhood to predict obesity risk

    Medida de energia total do leite materno de mães de trigêmeos, gêmeos e filhos únicos Total energy supplied by the human milk from mothers of triplet, twin and single neonates

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    OBJETIVO: Comparar a energia total do leite materno de mães de trigêmeos, gêmeos e filhos únicos. MÉTODOS: Estudo transversal e controlado feito com mães usuárias do banco de leite do Hospital Israelita Albert Einstein. Foram analisadas seis amostras de leite materno de mães de trigêmeos, 13 de gêmeos e 17 de filhos únicos, coletadas sob paramentação, conforme normas técnicas da Rede Brasileira de Bancos de Leite Humano. A análise foi realizada por meio do teste de crematócrito e os resultados submetidos à análise de variância de Kuskal-Wallis. RESULTADOS: A energia total do leite materno de mães de trigêmeos apresentou mediana de calorias maior (651kcal/L), quando comparada à do leite de mães de filhos únicos (560kcal/L) (p<0,05). O leite das mães de gêmeos e o de mães de filhos únicos não foram diferentes. Os trigêmeos apresentaram peso ao nascer menor (mediana 1344g) em relação aos filhos únicos (1975g) (p<0,01). Não foi observada diferença estatística em relação à idade gestacional e à idade materna entre os três grupos de neonatos. CONCLUSÕES: Pode-se concluir que o presente estudo, o primeiro na literatura sobre o tema, apontou para a presença de maior valor de energia total no leite de mães de recém-nascidos trigemelares. Futuros estudos são necessários para elucidar os mecanismos envolvidos nesse achado.<br>OBJECTIVE: To compare the total energy of the human milk of mothers of triplets, twins and single-children. METHODS: A cross-sectional and controlled study with mothers from the Human Milk Bank of Hospital Israelita Albert Einstein was performed. Six samples of triplet, 13 of twin and 17 of only-child mother's milk were analyzed. The milk samples were collected according to the Brazilian Human Milk Banks Network techniques and procedures and were analyzed by creamatocrit method. The results were compared by Kruskal-Wallis variance test. RESULTS: The total milk energy from triplets mothers was statistically higher (median - 651kcal/L) than single-child mothers (560kcal/L) (p<0.05). The milk of twin mothers and of single child mothers, regarding energy content, were similar. The triplet neonates presented lower birth weight (median-1344g) when compared to single neonates (1975g) (p<0.01). There was no significant difference among the studied groups regarding maternal age and gestational age. CONCLUSIONS: The present study, the first addressing this subject in literature, indicates a higher value of total energy in milk from triplets' mothers. However, further studies are necessary to clarify the mechanisms of this finding
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