Longitudinal Correlations between Molecular Compositions of Stratum Corneum and Breast Milk Factors during Infancy: A Prospective Birth Cohort Study.

Breast milk contains numerous factors that are involved in the maturation of the immune system and development of the gut microbiota in infants. These factors include transforming growth factor-ß1 and 2, immunoglobin A, and lactoferrin. Breast milk factors may also affect epidermal differentiation and the stratum corneum (SC) barrier in infants, but no studies examining these associations over time during infancy have been reported. In this single-center exploratory study, we measured the molecular components of the SC using confocal Raman spectroscopy at 0, 1, 2, 6, and 12 months of age in 39 infants born at our hospital. Breast milk factor concentrations from their mothers' breast milk were determined. Correlation coefficients for the two datasets were estimated for each molecular component of the SC and breast milk factor at each age and SC depth. The results showed that breast milk factors and molecular components of the SC during infancy were partly correlated with infant age in months and SC depth, suggesting that breast milk factors influence the maturation of the SC components. These findings may improve understanding of the pathogenesis of skin diseases associated with skin barrier abnormalities.

In vivo analysis of the stratum corneum of Japanese neonates and infants using confocal Raman spectroscopy: a pilot study.

BACKGROUND: Physiological skin properties of neonates and infants change drastically after birth and are implicated in the onset of atopic dermatitis and other diseases. Studies have measured physiological skin properties in infants; however, how these properties change over time remains unclear. No reports have measured ceramide in the stratum corneum of infants using confocal Raman spectroscopy; hence, we used it to measure the physiological properties of the skin, including ceramide, in infants. MATERIALS AND METHODS: The water content and other factors in the skin of infants aged 0, 1, and 6 months were measured. All measurements were performed five times indoors at 22 ± 2°C and 50% ± 10% relative humidity in the middle of the calf at 4-µm distances, and their mean was calculated. RESULTS: The water content of the area between the skin surface and superficial layers was the lowest in newborns as compared with other ages, and the deeper the skin layer, the higher the water content. The stratum corneum, evaluated using confocal Raman spectroscopy, was the thickest in newborns and gradually thinned with age. Its water content was the lowest in newborns. The levels of natural moisturizing factor, ceramide, and cholesterol were higher in newborns and tended to decrease with age. CONCLUSION: This report is the first to evaluate ceramide in the stratum corneum of infants using confocal Raman spectroscopy and could help in conducting subsequent longitudinal measurements of physiological skin properties in neonates and infants.

Association between Maternal Characteristics and Immune Factors TGF-ß1, TGF-ß2, and IgA in Colostrum: An Exploratory Study in Japan.

Colostrum is the first food for newborns and it contains various crucial immune factors. The concentrations of immune factors in breast milk may change depending on maternal characteristics such as body mass index, collection day, and age at first pregnancy. In this exploratory study, we investigated the association between TGF-ß1, TGF-ß2, and IgA in colostrum and rarely studied factors that affect breast milk components, including the use of labor-inducing medication, colostrum secretion, sex of newborns, breast or nipple problems, and nipple care. Breast milk samples were collected from 42 mothers and analyzed for TGF-ß1, TGF-ß2, and IgA. The results suggest that parity and mode of delivery may be correlated with the concentrations of immune factors in colostrum. However, we found no association between the immune factors in colostrum and the use of labor-inducing medications, colostrum secretion, sex of newborns, breast or nipple problems, and nipple care. These findings have some implications for further analysis of the effects of immune factors in breast milk on the prognosis of allergies in children.

Estrogen increases hair pigmentation in female recessive yellow mice.

Murine recessive yellow (Mc1r(e)) is a loss-of-function mutation in the receptor for alpha-melanocyte-stimulating hormone, melanocortin receptor 1 (Mc1r), and results in a yellow coat by inducing pheomelanin synthesis in hair follicular melanocytes. We previously showed that eumelanin and pheomelanin content in dorsal hair in female Mc1r(e)/Mc1r(e) mice 5 weeks after birth was greater than that in male mice. To better understand the sex difference in hair pigmentation, estrogen, progesterone, and androgen were injected subcutaneously to newborn mice, and the effects of these sex hormones on hair pigmentation at 8.5 days were investigated. Although these sex hormones failed to affect the ratio of pheomelanic to eumelanic hair, they increased total hair pigmentation. Chemical analyses showed that total melanin content was increased by a low dose of estrogen in female mice. Moreover, estrogen increased pheomelanin content in female hair, whereas the hormone greatly decreased both eumelanin and pheomelanin content in male hair. High doses of progesterone, in contrast, increased total melanin content in both female and male hair. Moreover, a high dose of androgen increased total melanin content exclusively in male hair. These results suggest that estrogen is the main factor in determining the higher content of eumelanin and pheomelanin in female hair of Mc1r(e)/Mc1r(e) mice.