Activation of sphingosine kinase in pheochromocytoma PC12 neuronal cells in response to trophic factors

AbstractNerve growth factor (NGF), basic fibroblast growth factor (bFGF), dibutyryl cAMP and forskolin, known differentiating agents for pheochromocytoma PC12 cells, induced sustained activation of sphingosine kinase, the enzyme responsible for the formation of the sphingolipid second messenger, sphingosine-1-phosphate, which mediates the mitogenic effects of certain growth factors. In contrast, epidermal growth factor and insulin-like growth factor-1, which stimulate proliferation of PC12 cells, induced only small and transient increases in sphingosine kinase activity. Of the growth factors examined, NGF was the most potent activator of sphingosine kinase, inducing a 4-fold increase in Vmax. Sphingosine kinase activity induced by NGF, but not FGF, was blocked by the protein kinase inhibitor K252a when added simultaneously, with minimal effect when added after 60 min. Thus, activation of sphingosine kinase may have an important role in neural differentiation

Nothing Short of Really Healthy Children: Mothers, the Children's Bureau, and Disability, 1914 - 1933

In 1931 the United States Children's Bureau asserted that "nothing short of really healthy children should satisfy parents." This thesis examines how literature published by the Children's Bureau from 1913 to 1933 shaped perceptions of motherhood and of maternal control over the body. As the bureau taught mothers how to care for their children, it also taught them that by following bureau advice, mothers could shape the bodies of their children to adhere to normative body standards. The research considers the relationship between mothers, the state, and the physical body. This thesis is divided into chapters about prenatal care and maternal marking; infant care and maternal policing; and child care and maternal control

Campaign Finance Reform: The Unfinished Agenda

In 1974, following the Watergate scandal, Congress enacted major campaign finance reform legislation. The legislation created a revolutionary new public financing system for our presidential campaigns, but it left congressional campaigns to be financed totally by private money. The presidential public financing system has worked well. Despite some incremental problems, the system has accomplished its basic goal of allowing individuals to run for the presidency without becoming dependent on their financial backers. The system for financing congressional cam paigns, on the other hand, is out of control and in need of fundamental reform. The inappropriate role of special interest political action commit tees (PACs) in influencing congressional elections and congressional decisions is the single biggest problem facing the political process. Congress needs to complete the unfinished campaign finance reform agenda of the 1970s by enacting public financing for congressional campaigns and establishing new restrictions on the total amount that PACs may give to a congressional candidate.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67356/2/10.1177_000271628648600107.pd

MetaWards: A flexible metapopulation framework for modelling disease spread

This is the final version. Available on open access from Open Journals via the DOI in this recordThe software is available at https://github.com/metawards/MetaWardsUnderstanding how disease spreads through populations is important when designing and implementing control measures. MetaWards implements a stochastic metapopulation model of disease transmission that enables geographical modelling of disease spread that can scale all the way from modelling local transmission up to full national-or international-scale outbreaks. It is built in Python and has a flexible plugin architecture to support complex scenario modelling. This enables the code to be adapted to model new situations and new control measures as they arise, e.g. emergence of new variants of disease, enaction of different types of movement restrictions, availability of different types of vaccines etc. It implements a userdefinable compartmental transmission model, such as an SIR model, that can be extended multi-dimensionally via multiple demographics or sub-populations, and multiple geographical regions. Models can be constructed from the various sources of movement and demographic data that are available, and are accelerated via Cython (Behnel et al., 2020), OpenMP, Scoop (Hold & Gagnon, 2019) and MPI4Py (Dalcin & Fang, 2021) to scale efficiently from running on personal laptops to large supercomputers. Python, R and command line interfaces and a complete set of tutorials empower researchers to adapt their models to a variety of scenarios.Engineering and Physical Sciences Research Council (EPSRC)Medical Research Council (MRC)Alan Turing InstitutePfize

Epigenetic and transcriptional dysregulation in CD4+ T cells in patients with atopic dermatitis

Atopic dermatitis (AD) is one of the most common skin disorders among children. Disease etiology involves genetic and environmental factors, with 29 independent AD risk loci enriched for risk allele-dependent gene expression in the skin and CD4+ T cell compartments. We investigated the potential epigenetic mechanisms responsible for the genetic susceptibility of CD4+ T cells. To understand the differences in gene regulatory activity in peripheral blood T cells in AD, we measured chromatin accessibility (an assay based on transposase-accessible chromatin sequencing, ATAC-seq), nuclear factor kappa B subunit 1 (NFKB1) binding (chromatin immunoprecipitation with sequencing, ChIP-seq), and gene expression levels (RNA-seq) in stimulated CD4+ T cells from subjects with active moderate-to-severe AD, as well as in age-matched non-allergic controls. Open chromatin regions in stimulated CD4+ T cells were highly enriched for AD genetic risk variants, with almost half of the AD risk loci overlapping AD-dependent ATAC-seq peaks. AD-specific open chromatin regions were strongly enriched for NF-κB DNA-binding motifs. ChIP-seq identified hundreds of NFKB1-occupied genomic loci that were AD- or control-specific. As expected, the AD-specific ChIP-seq peaks were strongly enriched for NF-κB DNA-binding motifs. Surprisingly, control-specific NFKB1 ChIP-seq peaks were not enriched for NFKB1 motifs, but instead contained motifs for other classes of human transcription factors, suggesting a mechanism involving altered indirect NFKB1 binding. Using DNA sequencing data, we identified 63 instances of altered genotype-dependent chromatin accessibility at 36 AD risk variant loci (30% of AD risk loci) that might lead to genotype-dependent gene expression. Based on these findings, we propose that CD4+ T cells respond to stimulation in an AD-specific manner, resulting in disease- and genotype-dependent chromatin accessibility alterations involving NFKB1 binding

CFTR Functions as a Bicarbonate Channel in Pancreatic Duct Cells

Pancreatic duct epithelium secretes a HCO3−-rich fluid by a mechanism dependent on cystic fibrosis transmembrane conductance regulator (CFTR) in the apical membrane. However, the exact role of CFTR remains unclear. One possibility is that the HCO3− permeability of CFTR provides a pathway for apical HCO3− efflux during maximal secretion. We have therefore attempted to measure electrodiffusive fluxes of HCO3− induced by changes in membrane potential across the apical membrane of interlobular ducts isolated from the guinea pig pancreas. This was done by recording the changes in intracellular pH (pHi) that occurred in luminally perfused ducts when membrane potential was altered by manipulation of bath K+ concentration. Apical HCO3− fluxes activated by cyclic AMP were independent of Cl− and luminal Na+, and substantially inhibited by the CFTR blocker, CFTRinh-172. Furthermore, comparable HCO3− fluxes observed in ducts isolated from wild-type mice were absent in ducts from cystic fibrosis (ΔF) mice. To estimate the HCO3− permeability of the apical membrane under physiological conditions, guinea pig ducts were luminally perfused with a solution containing 125 mM HCO3− and 24 mM Cl− in the presence of 5% CO2. From the changes in pHi, membrane potential, and buffering capacity, the flux and electrochemical gradient of HCO3− across the apical membrane were determined and used to calculate the HCO3− permeability. Our estimate of ∼0.1 µm sec−1 for the apical HCO3− permeability of guinea pig duct cells under these conditions is close to the value required to account for observed rates of HCO3− secretion. This suggests that CFTR functions as a HCO3− channel in pancreatic duct cells, and that it provides a significant pathway for HCO3− transport across the apical membrane