Smartphone use during breastfeeding and its impact on mother-infant interaction and maternal responsiveness: Within-subject design.

This study investigated the association between maternal smartphone use during breastfeeding and the quality of mother-infant interactions and maternal visual responsiveness to the infant's bids for attention. We observed 13 mother-infant dyads and video-recorded breastfeeding under the experimental (smartphone use) and control (no smartphone use) conditions on separate days. To evaluate the quality of mother-infant interactions between the two conditions, we used the Japanese revised version of the Assessment of Mother-Infant Sensitivity (AMIS) scale. The mothers' visual responses to their infants' bids for attention were categorized into two groups. In this study, although smartphone use clearly increased distracted feeding times, we found no significant associations between maternal smartphone use and the quality of mother-infant interactions or bonding during breastfeeding. However, smartphone use during breastfeeding was found to interfere with the mother's ability to respond visually to the infant's bid for her attention. The results of this study can be applied while developing resources regarding smartphone use for nursing mothers.

Mothers' habitual smartphone use, infants during breastfeeding, and mother-infant bonding: A longitudinal study.

The excessive use of digital media by breastfeeding mothers may reduce their responsiveness to their child. However, there are no longitudinal studies focusing on breastfeeding during infancy. This study aimed to examine mothers' habitual use of smartphones and their observations of their infants during breastfeeding and identifies changes in the relationship between mother's breastfeeding habits and bonding with their infants. This is a quantitative descriptive study based on a questionnaire survey conducted on the Internet. Two questionnaires were sent to and collected from Japanese mothers who were the registered members of the survey company; the first questionnaire was completed 1 to 3 months postdelivery and the second 6 months after the first (approximately 9 months after delivery). In total, 195 participants participated. Smartphone use during breastfeeding was habitual, but mothers simultaneously observed their infants. Mothers habitually used smartphones during breastfeeding shortly after giving birth; however, there was little connection to subsequent negative emotions toward their children or problems with bonding. It is necessary to continue to evaluate the behavior of the mother and child.

Dietary selenium deficiency or selenomethionine excess drastically alters organ selenium contents without altering the expression of most selenoproteins in mice.

Selenium is an essential trace element, and its deficiency can cause cardiomyopathy, arrhythmias and increased susceptibility to infection. Such clinical symptoms are considered primarily attributed to decreased expression of some of the 25 selenocysteine-containing selenoproteins in humans. Conversely, a selenium-excessive diet can cause acute poisoning and chronic symptoms with unknown mechanisms. To reveal the impact of selenium deficiency and excess on selenoprotein expression in vivo, mice (that possess 24 selenoproteins) were fed with selenium-deficient or selenomethionine-excessive diets for up to 4 weeks, and the expression levels of nine representative selenoproteins [glutathione peroxidase (Gpx) 1/2/3/4, thioredoxin reductase 1/2, deiodinase 1, and selenoprotein P/S] were measured in 10 organs (brain, heart, liver, lung, kidney, pancreas, spleen, testis, skeletal muscle and thymus). We observed a time-dependent decrease in the selenium content of most organs (except testis) of selenium-deficient mice but not in the expression levels of the nine selenoproteins, with the exceptions of Gpx1/2 in the heart/liver/kidney/pancreas/spleen and Gpx3 in the pancreas/spleen. Serum lipid peroxidation levels were up-regulated in response to Se deficiency because of the decreased expression/activity of Gpx3, a plasma-type Gpx. In contrast, a time-dependent increase was observed in the selenium content of all organs but not the expression levels of the nine selenoproteins in most organs of selenomethionine-excessive mice; however, markedly elevated protein-bound selenium levels were observed in the liver/kidney. These results suggest that the systemic response to selenium deficiency and selenomethionine excess involves the down-regulation of some selenoproteins such as Gpx1/Gpx3 and up-regulation of selenium-containing proteins (not selenoproteins), respectively.