Acid-sensing ion channels (ASICs) are expressed in various sensory and central neurons. The functional role of these channels remains elusive. Complex subunit combinations and lack of specific blockers for native receptors are likely to contribute to the difficulty of resolving the function of ASICs. Finding a neuronal cell line, which expresses a single population of ASICs, should prove to be useful in delineating the function of individual ASICs. Using patch-clamp, Ca(2+)-imaging, and RT-PCR techniques, we have explored the existence of ASICs in PC12 cells, a clonal neuronal cell line. Fast drops of extracellular pH activated transient inward currents in PC12 cells with pH(0.5) at 6.0-6.2. The ASICs in PC12 cells were selective for Na(+) with significant Ca(2+) permeability. Currents in PC12 cells were blocked by the nonselective ASIC blocker amiloride. PcTX1, a specific homomeric ASIC1a blocker, also blocked the ASIC currents with an IC(50) of approximately 1.5 nM. RT-PCR demonstrated the existence of ASIC1a transcript in both undifferentiated and nerve growth factor-differentiated PC12 cells. Our data suggest that PC12 cells likely contain a single population of functional proton-gated channel-homomeric ASIC1a. It might be an ideal neuronal cell line for the study of physiological and potential pathological roles of this key subunit of ASICs.

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We investigated the regulation of expression of bFGF and aFGF in cultures of normal human dermal fibroblasts grown in a defined, serum-free medium which did not contain FGF. Under these conditions we detected three molecular weight forms of bFGF protein [18.0, 23.0, and 26.6 kiloDaltons (kD)] and three molecular weight forms of aFGF protein (18.4, 19.2, and 28.6 kD) in these cells using western blot analysis. The addition of fetal bovine serum (FBS) to these cultures caused an accumulation of all three molecular weight forms of bFGF protein with a more dramatic accumulation of the 23.0 and 26.6 kD forms. In contrast, the addition of FBS to the cultures had no effect on the level of aFGF proteins. Analysis of mRNA isolated from cells grown in serum-free medium revealed multiple species of both bFGF and aFGF RNA with molecular weights that correlated with our previous observations. The abundance of all bFGF mRNA species increased dramatically after serum treatment while the abundance of aFGF mRNA species increased only slightly. Our observations demonstrate that factor(s) present in FBS elevate the levels of bFGF mRNA and protein beyond the levels already present in the cultures growing in serum-free medium. Moreover, both bFGF and aFGF protein are present in these cells as multiple molecular weight species. Some of these forms are higher in apparent molecular weight than would be predicted from ATG-initiated primary translation products of these genes. We also show that the cells used for this study proliferate in response to bFGF and aFGF, thus, it is possible that the growth of these cells could be subject to autocrine/paracrine control in certain conditions.

We update estimates of the maternal mortality impact of no abortions occurring in the U.S. following the recent release of new national and state abortion incidence data for 2020. This estimate quantifies the increase in maternal deaths that would occur after a total abortion ban solely due to the greater mortality risk of continuing pregnancy to term compared to having an abortion. We estimate the number of additional U.S. maternal deaths by race/ethnicity that would be caused if no abortion occurred, following previously published procedures and using published 2020 statistics on maternal mortality, births, and abortions. After the first year of no abortion occurring, we estimate increased exposure to the risks of pregnancy would cause an increase of 210 maternal deaths per year (24% increase), from 861 to 1071. The increase would be greatest among non-Hispanic Black people, for whom it would be 39%. We also estimate, by state, the number of additional maternal deaths caused by no abortion occurring in the 26 U.S. states that either have banned or the Guttmacher Institute estimates will soon ban abortion. We find that increases in some states would be as great as 29%, while in others, because of already extremely low abortion rates and numbers, less than 1 additional death would be expected. Banning abortion will likely change maternal mortality in ways beyond exposing more people to the existing risks of maternal death; any increase in maternal mortality due to these changes would be in addition to our estimates.

This article examines the tension between population-level and individual-level interests regarding childbearing, from Malthus's concern for overpopulation to the contemporary issue of son preference, and argues for an understanding of individual-level interests that distinguishes parents from households. In making this distinction, we draw attention to how gender norms can play an important role in shaping reproductive interests. Survey data and previous work show a wealth of differences in the number of children men and women would like to have, and in their behaviors toward the children they have. We argue not that gender norms cause women to want more children than men, but that they cause women to want children more, for reasons that include time spent with children, old-age support, women's proscribed opportunities for achieving social standing, and the relationship in many contexts between honorable female adulthood and bearing children at the right time and under the right circumstances. We further argue that a just and effective population policy must consider fertility outcomes at multiple scales, including that of the welfare of individual women.