Distribution of transcellular calcium and sodium transport pathways along mouse distal nephron

The organization of Na(+) and Ca(2+) transport pathways along the mouse distal nephron is incompletely known. We revealed by immunohistochemistry a set of Ca(2+) and Na(+) transport proteins along the mouse distal convolution. The thiazide-sensitive Na(+)-Cl(-) cotransporter (NCC) characterized the distal convoluted tubule (DCT). The amiloride-sensitive epithelial Na(+) channel (ENaC) colocalized with NCC in late DCT (DCT2) and extended to the downstream connecting tubule (CNT) and collecting duct (CD). In early DCT (DCT1), the basolateral Ca(2+)-extruding proteins [Na(+)/Ca(2+) exchanger (NCX), plasma membrane Ca(2+)-ATPase (PCMA)] and the cytoplasmic Ca(2+)-binding protein calbindin D(28K) (CB) were found at very low levels, whereas the cytoplasmic Ca(2+)/Mg(2+)-binding protein parvalbumin was highly abundant. NCX, PMCA, and CB prevailed in DCT2 and CNT, where we located the apical epithelial Ca(2+) channel (ECaC1). Its subcellular localization changed from apical in DCT2 to exclusively cytoplasmic at the end of CNT. NCX and PMCA decreased in parallel with the fading of ECaC1 in the apical membrane. All three of them were undetectable in CD. These findings disclose DCT2 and CNT as major sites for transcellular Ca(2+) transport in the mouse distal nephron. Cellular colocalization of Ca(2+) and Na(+) transport pathways suggests their mutual interactions in transport regulation

Income, Relationship Quality, and Parenting: Associations With Child Development in Two-Parent Families

Prior research suggests considerable heterogeneity in the advantages of living in a two-parent family. Specifically, children living with married biological parents exhibit more favorable outcomes than children living with cohabiting biological parents and with married and cohabiting stepparents. To explain these differences, researchers have focused almost exclusively on differences in the levels of factors such as income, parental relationship quality, and parenting quality across family types. In this paper, we examined whether differences in the benefits associated with these factors might also account for some of the variation in children’s cognition and social-emotional development. Focusing on children at the time they enter kindergarten, we found only weak evidence of differences in benefits across family types. Rather, we found that children living in stepfather families experienced above average levels of parental relationship quality and parenting quality which, in turn, played a protective role vis-à-vis their cognitive and social-emotional development