25 Years of Research in Human Lactation: From Discovery to Translation.

Researchers have recently called for human lactation research to be conceptualized as a biological framework where maternal and infant factors impacting human milk, in terms of composition, volume and energy content are studied along with relationships to infant growth, development and health. This approach allows for the development of evidence-based interventions that are more likely to support breastfeeding and lactation in pursuit of global breastfeeding goals. Here we summarize the seminal findings of our research programme using a biological systems approach traversing breast anatomy, milk secretion, physiology of milk removal with respect to breastfeeding and expression, milk composition and infant intake, and infant gastric emptying, culminating in the exploration of relationships with infant growth, development of body composition, and health. This approach has allowed the translation of the findings with respect to education, and clinical practice. It also sets a foundation for improved study design for future investigations in human lactation

Four-Week Nutritional Audit of Preterm Infants Born <33 Weeks Gestation

Aim: Preterm nutritional audits have previously been conducted using assumed milk composition. We audited protein and energy intakes in the first 28 days of preterm life using both assumed milk composition and milk analysis to assess their effect on weight gain and to determine if the recommended reasonable range of intakes were met. Methods: Parenteral and enteral intakes and weight gain were recorded daily for infants (n = 63) born <33 weeks gestation, using assumed milk composition. Macronutrient composition was determined by milk analysis for a subset of infants (n = 36). Linear mixed models analysis was used to assess the influence of energy and protein intakes on weight gain. Results: (Data median (range)): Infants (n = 63) gestation and birth weight were 30 (24–32) weeks and 1400 (540–2580) g, respectively. Macronutrient milk composition was variable: protein 16.6 (13.4–27.6) g/L, fat 46.1 (35.0–62.4) g/L, lactose 68.0 (50.9–74.8) g/L, energy 3074 (2631–3761) kJ/L. Intakes based on measured composition differed from assumed. Protein intake was significantly associated with weight gain. Compared to infants with longer gestations, those born <28 weeks gestation were fed lower volumes, were more reliant on parenteral nutrition, took an additional seven days to transition to fortified feeds and median weight gain velocity took a fortnight longer to reach targets.Conclusion: Preterm milk composition is variable and routine fortification using assumed composition may result in inappropriate nutrition. Fortification regimens stratified by birth gestation may be necessary to achieve preterm nutrition and growth targets. Milk analysis is required for accurate nutritional audit

Consideration of influences of soil parameters on compaction behavior with soil/water/air coupled F. E. code

Background: The essential amino acid methionine can be used for protein synthesis but also serves as a precursor for homocysteine and cysteine. Objective: The objective of this study was to determine the minimal obligatory methionine requirement of infants in the presence of excess cysteine (91 mg · k

Modulação e composição de ácidos graxos do leite humano

O leite humano é um fluido complexo, considerado um alimento completo e suficiente para suprir as necessidades nutricionais de recém-nascidos durante os seis primeiros meses de vida. A fração lipídica do leite materno é a principal fonte de energia para o neonato e possui ácidos graxos essenciais; seus produtos poliinsaturados, como o ácido araquidônico e o ácido docosa-hexaenoico, são indispensáveis ao crescimento. Tanto o conteúdo lipídico quanto o tipo de ácido graxo do leite humano podem ser modulados por fatores inerentes ou não à mãe. Dentre esses fatores, destacam-se a adiposidade, o estilo de vida, o estado nutricional e a ingestão alimentar materna, que agem de forma concomitante e interdependente, dificultando as análises dos estudos que se propõem investigar tal modulação. Não se observam grandes diferenças entre as composições de ácidos graxos do leite materno de estudos realizados na América Latina e em países desenvolvidos. O leite das nutrizes de algumas regiões brasileiras apresenta os ácidos graxos essenciais, o ácido araquidônico, o ácido docosa-hexaenoico e um baixo percentual de ácidos graxos saturados e ácidos graxos trans. O presente trabalho avaliou, portanto, os principais fatores que modulam a composição do leite humano, em particular as diferenças na composição de ácidos graxos do leite de mulheres de diferentes nacionalidades e os efeitos desses componentes sobre a saúde do recém-nascido.Human milk is a complex fluid, considered a complete food and enough to meet the nutritional needs of an infant during the first six months of life. The lipid fraction of breastmilk is the newborn's main source of energy. It contains essential fatty acids and its polyunsaturated fats, such as arachidonic acid and docosahexaenoic acid, are essential for growth. Both the lipid content and the kind of fatty acids in human breastmilk can be modulated by factors inherent or not to the mother. Among these factors, adiposity, lifestyle, nutritional status and maternal food intake act in a concomitant and independent manner, making this modulation more difficult to analyze. Few differences have been observed between the fatty acid composition of human milk from studies carried out in Latin America and developed countries. Milk from some women from certain Brazilian regions has the essential fatty acids, arachidonic acid and docosahexaenoic acid, and a low percentage of saturated and trans fatty acids. Thus, the present study assessed the main factors that modulate the composition of human milk, in particular the differences in fatty acid composition among mothers of different nationalities, and the effects of these components on the newborn's health

Antimicrobial protein and Peptide concentrations and activity in human breast milk consumed by preterm infants at risk of late-onset neonatal sepsis

Objective: We investigated the levels and antimicrobial activity of antimicrobial proteins and peptides (AMPs) in breast milk consumed by preterm infants, and whether deficiencies of these factors were associated with late-onset neonatal sepsis (LOS), a bacterial infection that frequently occurs in preterm infants in the neonatal period. Study design: Breast milk from mothers of preterm infants (≤32 weeks gestation) was collected on days 7 (n = 88) and 21 (n = 77) postpartum. Concentrations of lactoferrin, LL-37, beta-defensins 1 and 2, and alpha-defensin 5 were measured by enzyme-linked immunosorbent assay. The antimicrobial activity of breast milk samples against Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, and Streptococcus agalactiae was compared to the activity of infant formula, alone or supplemented with physiological levels of AMPs. Samples of breast milk fed to infants with and without subsequent LOS were compared for levels of AMPs and inhibition of bacterial growth. Results: Levels of most AMPs and antibacterial activity in preterm breast milk were higher at day 7 than at day 21. Lactoferrin was the only AMP that limited pathogen growth >50% when added to formula at a concentration equivalent to that present in breast milk. Levels of AMPs were similar in the breast milk fed to infants with and without LOS, however, infants who developed LOS consumed significantly less breast milk and lower doses of milk AMPs than those who were free from LOS. Conclusions: The concentrations of lactoferrin and defensins in preterm breast milk have antimicrobial activity against common neonatal pathogens

Επίδραση των αναβολικών στεροειδών στους ιστούς (μέρος 10: γενική θεωρία επίδρασης και επίδραση στο κόκκαλο)

Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Εφαρμοσμένη Μηχανική