2,693 research outputs found

    Compton Scattering on Black Body Photons

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    We examine Compton scattering of electrons on black body photons in the case where the electrons are highly relativistic, but the center of mass energy is small in comparison with the electron mass. We derive the partial lifetime of electrons in the LEP accelerator due to this form of scattering in the vacuum beam pipe and compare it with previous results.Comment: Comments revised, 16 pages, ReVTeX, 2 Postscript figure

    Social justice themed sermons from civic-minded clergy can push churchgoers towards greater activism to improve racial equality

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    Religion plays an important role in the lives of many Americans. But what role does religion and religious institutions play in motivating Americans to participate in politics? In their new book, R. Khari Brown, Ronald E. Brown, and James S. Jackson look at the role the spiritual and political efforts made by churches to improve human rights. They find that Black Americans are more likely than White and Hispanic Americans to believe that religious institutions have a moral obligation towards human rights activism, but that all groups are more likely to engage in acts like protests if they attend worship settings where they hear sermons about social justice issues and the importance of political activism

    Detection of thyrotropin binding inhibitory activity in neonatal blood spots

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    Recent studies have suggested that maternal TSH receptor-blocking antibodies might be of primary etiological importance in some cases of transient congenital hypothyroidism (CH). Because these antibodies are extremely potent, we evaluated the feasibility of identifying babies at risk by using readily available newborn blood spots. Blood spots obtained from 84 normal babies (group 1) and from 354 infants whose initial T4 was less than the tenth percentile for the assay and whose TSH was 40 mU/L or more (group 2) were studied without knowledge of the diagnosis. Blood was eluted from spots overnight and evaluated for [125I]TSH binding inhibition (TBI) to solubilized porcine thyroid membranes. Four spots obtained from 3 group 2 babies, but none of those from the group 1 infants, exhibited TBI activity greater than 3 SD above the normal mean (33.9%). Four additional hypothyroxinemic infants whose mothers had Graves\u27 disease were also negative. Subsequent follow-up revealed that all 3 positive babies had transient CH, and all 3 mothers had primary myxedema. Potent TBI activity was confirmed in the serum of all 3 mothers and in the 2 babies in whom it was evaluated at birth. We conclude that newborn blood spots can be used to detect potent maternal TBI activity, and that this identifies a baby likely to have transient, rather than permanent, CH. Because of their stability and ease of collection and handling, newborn blood spots should offer a convenient tool for future studies aimed at defining in more detail the incidence and clinical characteristics of this unique syndrome

    Endocrine Regulation of Phosphate Homeostasis

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    author's chapter in edited workPhosphate, a component of nucleic acids, DNA and RNA, is incorporated in the structure of phospholipids in cell membranes, and is involved in many biological functions such as cell signaling, energy metabolism, and bone mineralization. Phosphate homeostasis is regulated by intestinal phosphate absorption, renal phosphate reabsorption, and skeletal phosphate resorption. Renal and intestinal transport of inorganic phosphate is controlled by sodium-phosphate cotransporters. Endocrine regulators that target bone, kidneys, and intestines during phosphate homeostasis include parathyroid hormone, vitamin D, fibroblast growth factor 23 (FGF23), and Klotho. Dysregulated serum phosphate falls within two categories: hypophosphatemia and hyperphosphatemia. Some genetic disorders such as hypophosphatemic rickets overexpress FGF23, inhibiting renal reabsorption of inorganic phosphate, while other disorders such as familial tumor calcinosis inhibit the expression of FGF23, causing hyperphosphatemia. Conditions associated with phosphate toxicity include chronic kidney disease, vascular calcification, tumorigenesis, and premature aging

    Dysregulation of Phosphate Metabolism and Conditions Associated With Phosphate Toxicity

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    Phosphate homeostasis is coordinated and regulated by complex cross-organ talk through delicate hormonal networks. Parathyroid hormone (PTH), secreted in response to low serum calcium, has an important role in maintaining phosphate homeostasis by influencing renal synthesis of 1,25-dihydroxyvitamin D, thereby increasing intestinal phosphate absorption. Moreover, PTH can increase phosphate efflux from bone and contribute to renal phosphate homeostasis through phosphaturic effects. In addition, PTH can induce skeletal synthesis of another potent phosphaturic hormone, fibroblast growth factor 23 (FGF23), which is able to inhibit renal tubular phosphate reabsorption, thereby increasing urinary phosphate excretion. FGF23 can also fine-tune vitamin D homeostasis by suppressing renal expression of 1-alpha hydroxylase (1α(OH)ase). This review briefly discusses how FGF23, by forming a bone-kidney axis, regulates phosphate homeostasis, and how its dysregulation can lead to phosphate toxicity that induces widespread tissue injury. We also provide evidence to explain how phosphate toxicity related to dietary phosphorus overload may facilitate incidence of noncommunicable diseases including kidney disease, cardiovascular disease, cancers and skeletal disorders

    Phosphate toxicity and tumorigenesis

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    The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.bbcan.2018.04.007 © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/In this article, we briefly summarized evidence that cellular phosphate burden from phosphate toxicity is a pathophysiological determinant of cancer cell growth. Tumor cells express more phosphate cotransporters and store more inorganic phosphate than normal cells, and dysregulated phosphate homeostasis is associated with the genesis of various human tumors. High dietary phosphate consumption causes the growth of lung and skin tumors in experimental animal models. Additional studies show that excessive phosphate burden induces growth-promoting cell signaling, stimulates neovascularization, and is associated with chromosome instability and metastasis. Studies have also shown phosphate is a mitogenic factor that affects various tumor cell growth. Among epidemiological evidence linking phosphate and tumor formation, the Health Professionals Follow-Up Study found that high dietary phosphate levels were independently associated with lethal and high-grade prostate cancer. Further research is needed to determine how excessive dietary phosphate consumption influences initiation and promotion of tumorigenesis, and to elucidate prognostic benefits of reducing phosphate burden to decrease tumor cell growth and delay metastatic progression. The results of such studies could provide the basis for therapeutic modulation of phosphate metabolism for improved patient outcome

    Atomoxetine treatment in children and adolescents with attention-deficit hyperactivity disorder: what are the long-term health-related quality-of-life outcomes?

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    OBJECTIVE: Numerous investigations have examined the efficacy of pharmacological treatment for attention-deficit/hyperactivity disorder (ADHD) in children. However, relatively few studies have addressed the impact of treatment on long-term subjective, psychosocial outcomes, such as health-related quality of life (HRQL). This study examines the long-term effects of pharmacological treatment with atomoxetine on HRQL in children and adolescents with ADHD. METHODS: Participants included 6- to 17-year-old children and adolescents (n = 912) with ADHD enrolled in a 24-month, multicenter, open-label trial of atomoxetine. Outcomes included clinician ratings of ADHD, parent ratings of ADHD, and a widely used measure of HRQL (The Child Health Questionnaire (CHQ)). Treatment response rates were calculated based on a CHQ improvement of at least 1 standard error of measurement. RESULTS: Significant improvements in HRQL were found following both acute and long-term treatment for psychosocial but not physical health. Of participants who completed treatment (n = 312 or 34.2% of those enrolled), 81% responded to acute treatment and 78% responded to long-term treatment. Improvements noted after acute treatment were maintained during long-term treatment with the majority of participants (86%) continuing to respond to treatment. CONCLUSIONS: Atomoxetine is associated with improvements in HRQL, and the improvements are generally stable over time

    Abnormal microtubule packing in processes of SF9 cells expressing the FTDP-17 V337M tau mutation

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    AbstractMutations in the gene for the microtubule associated protein, tau have been identified for fronto-temporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17). In vitro data have shown that FTDP-17 mutant tau proteins have a reduced ability to bind microtubules and to promote microtubule assembly. Using the baculovirus system we have examined the effect of the V337M mutation on the organization of the microtubules at the ultrastructural level. Our results show that the organization of the microtubules is disrupted in the presence of V337M tau with greater distances between the microtubules and fewer microtubules per process

    Vitamin D supplements: Magic pill or overkill?

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    Vitamin D is a multifunctional micronutrient that exerts hormonal effects on many organs of the body. 1,25 dihydroxyvitamin D is the active metabolite of vitamin D, formed by dual hydroxylation in the liver and kidney
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