Breastfeeding,schooling, and income: Insights from the Indonesian Family Life Survey

Recent research has highlighted associations of breastfeeding with IQ, schooling, and income, but uncertainty about such links remains. The Indonesian Family Life Survey, representative of 83% of the Indonesian population, provides data on breastfeeding, parents' years of schooling, wealth, and other family characteristics in 1993–1994, as well as schooling and income in 2014–2015 for 5,421 children of those families. Using linear regressions and controlling for village or neighbourhood, as well as propensity score matching, we analysed breastfeeding associations for boys and girls separately, when regularly fed foods/beverages other than breast milk is significantly associated with years of schooling in 2014–2015 for girls, but not for boys, after controlling for the village or neighbourhood of residence in 1993–1994. For girls, ages 1 to 1.9, 2 to 2.9, 3 to 3.9, and >4 months, relative to ages <1 month, are associated with an additional 0.41 to 0.46 years of schooling, with p values of 0.086, 0.071, 0.043, and 0.026, respectively. No comparable estimate for boys attains statistical significance. Using propensity score matching yields similar results. Associations with annual income in 2014–2015 are not statistically significant, either for all children, or for either sex. Our finding suggests that delaying regular feeding of foods/beverages other than breast milk beyond 1 month may help girls' schooling but has no observable association with annual income, perhaps because of lower labour force participation by women. Also, the inclusion of controls for village or neighbourhood of residence reduces confounding.     

Temperospatial Expression of Matrix Metalloproteinases 1, 2, 3, and 9 During Early Tooth Development

Odontogenesis involves a complex series of processes including epithelial-mesenchymal interactions, morphogenesis, differentiation, fibrillogenesis, and mineralization. Extracellular (ECM) remodeling plays a critical role in the rapid morphological changes that accompany these events. It is proposed that matrix metalloproteinases (MMPs) participate in the remodeling of tooth-specific matrices that accompanies the developmental events. MMPs are zinc-requiring endopeptidases that are centrally involved in the controlled turnover of ECM components and are key to a varied range of developmental processes. Thus, the aim of this study was to examine the expression of MMPs 1, 2, 3, and 9 within the developing tooth germ of Wistar rats, using immunohistochemical localisation. During the bud stage, MMPs 1, 2, 3, and 9 were expressed within both epithelial and mesenchymal cells. Later on, during the cap stage, differential expression was observed; of note was the expression of MMP 3 within the enamel knot. This study reports the temperospatial expression of MMPs 1, 2, 3, and 9 during early tooth development, and points to them having a key role during this important developmental period.