25 research outputs found

    Lubiprostone Stimulates Duodenal Bicarbonate Secretion in Rats

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    Lubiprostone, a bicyclic fatty acid, is used for the treatment of chronic constipation. No published study has addressed the effect of lubiprostone on intestinal ion secretion in vivo. The aim of this study was to test the hypothesis that lubiprostone augments duodenal HCO3 − secretion (DBS). Rat proximal duodenal loops were perfused with pH 7.0 Krebs, control vehicle (medium-chain triglycerides), or lubiprostone (0.1–10 μM). We measured DBS with flow-through pH and CO2 electrodes, perfusate [Cl−] with a Cl− electrode, and water flux using a non-absorbable ferrocyanide marker. Some rats were pretreated with a potent, selective CFTR antagonist, CFTRinh-172 (1 mg/kg, ip), 1 h before experiments. Perfusion of lubiprostone concentration dependently increased DBS, whereas net Cl− output and net water output were only increased at 0.1 μM, compared with vehicle. CFTRinh-172 reduced lubiprostone (10 μM)-induced DBS increase, whereas net Cl− output was also unchanged. Nevertheless, CFTRinh-172 reduced basal net water output, which was reversed by lubiprostone. Furthermore, lubiprostone-induced DBS was inhibited by EP4 receptor antagonist, not by an EP1/2 receptor antagonist or by indomethacin pretreatment. In this first study of the effect of lubiprostone on intestinal ion secretion in vivo, lubiprostone stimulated CFTR-dependent DBS without changing net Cl− secretion. This effect supports the hypothesis that Cl− secreted by CFTR is recycled across the apical membrane by anion exchangers. Recovery of water output during CFTR inhibition suggests that lubiprostone may improve the intestinal phenotype in CF patients. Furthermore, increased DBS suggests that lubiprostone may protect the duodenum from acid-induced injury via EP4 receptor activation

    Ordering theories: typologies and conceptual frameworks for sociotechnical change

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    What theories or concepts are most useful at explaining socio technical change? How can – or cannot – these be integrated? To provide an answer, this study presents the results from 35 semi-structured research interviews with social science experts who also shared more than two hundred articles, reports and books on the topic of the acceptance, adoption, use, or diffusion of technology. This material led to the identification of 96 theories and conceptual approaches spanning 22 identified disciplines. The article begins by explaining its research terms and methods before honing in on a combination of fourteen theories deemed most relevant and useful by the material. These are: Sociotechnical Transitions, Social Practice Theory, Discourse Theory, Domestication Theory, Large Technical Systems, Social Construction of Technology, Sociotechnical Imaginaries, Actor-Network Theory, Social Justice Theory, Sociology of Expectations, Sustainable Development, Values Beliefs Norms Theory, Lifestyle Theory, and the Unified Theory of Acceptance and Use of Technology. It then positions these theories in terms of two distinct typologies. Theories can be placed into five general categories of being centered on agency, structure, meaning, relations or norms. They can also be classified based on their assumptions and goals rooted in functionalism, interpretivism, humanism or conflict. The article lays out tips for research methodology before concluding with insights about technology itself, analytical processes associated with technology, and the framing and communication of results. An interdisciplinary theoretical and conceptual inventory has much to offer students, analysts and scholars wanting to study technological change and society

    Формирование эмоциональной культуры как компонента инновационной культуры студентов

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    Homozygosity has long been associated with rare, often devastating, Mendelian disorders1 and Darwin was one of the first to recognise that inbreeding reduces evolutionary fitness2. However, the effect of the more distant parental relatedness common in modern human populations is less well understood. Genomic data now allow us to investigate the effects of homozygosity on traits of public health importance by observing contiguous homozygous segments (runs of homozygosity, ROH), which are inferred to be homozygous along their complete length. Given the low levels of genome-wide homozygosity prevalent in most human populations, information is required on very large numbers of people to provide sufficient power3,4. Here we use ROH to study 16 health-related quantitative traits in 354,224 individuals from 102 cohorts and find statistically significant associations between summed runs of homozygosity (SROH) and four complex traits: height, forced expiratory lung volume in 1 second (FEV1), general cognitive ability (g) and educational attainment (nominal p<1 × 10−300, 2.1 × 10−6, 2.5 × 10−10, 1.8 × 10−10). In each case increased homozygosity was associated with decreased trait value, equivalent to the offspring of first cousins being 1.2 cm shorter and having 10 months less education. Similar effect sizes were found across four continental groups and populations with different degrees of genome-wide homozygosity, providing convincing evidence for the first time that homozygosity, rather than confounding, directly contributes to phenotypic variance. Contrary to earlier reports in substantially smaller samples5,6, no evidence was seen of an influence of genome-wide homozygosity on blood pressure and low density lipoprotein (LDL) cholesterol, or ten other cardio-metabolic traits. Since directional dominance is predicted for traits under directional evolutionary selection7, this study provides evidence that increased stature and cognitive function have been positively selected in human evolution, whereas many important risk factors for late-onset complex diseases may not have been

    Inhibitory effects of diesel exhaust components and flavonoids on 20α-hydroxysteroid dehydrogenase activity in mouse tissues

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    The inhibitory effects of diesel exhaust components and flavonoids on 20α-hydroxysteroid dehydrogenase (20α-HSD) activity were examined in cytosolic fractions from the liver, kidney and lung of male mice. 9,10-Phenanthrenequinone (9,10-PQ) and 1,2-naphthoquinone (1,2-NQ), which are contained in diesel exhaust particles (DEPs), potently inhibited 20α-HSD activity in liver cytosol. 9,10-PQ also inhibited the enzyme activity in lung cytosol. However, 20α-HSD activity in kidney cytosol was little inhibited by 9,10-PQ or 1,2-NQ. Flavonoids such as quercetin, fisetin and kaempferol exhibited high inhibitory potencies for 20α-HSD activity in liver cytosol, whereas these flavonoids were poor inhibitors for the enzyme activity in kidney cytosol. It is likely that several diesel exhaust components and flavonoids augment the signaling of progesterone in the liver cells, by inhibiting potently 20α-HSD activity in mouse liver cytosol. The possibility that there are distinct enzymes catalyzing 20α-HSD activity in non-reproductive tissues of male mice is also discussed

    LED Lighting Across Borders: Exploring the plea for darkness and value-sensitive design with Libbrecht’s comparative philosophy model

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    This chapter discusses how a comparative philosophical model can contribute to both substantive and procedural values in energy policy. We discuss the substantive values in the mainstream light-emitting diodes (LEDs) debate and Taylor Stone's alternative plea for darkness. We also explore Value Sensitive Design as a procedural approach. We conclude that the comparative philosophical model of Ulrich Libbrecht can appropriately broaden the set of substantive values used in VSD. We discuss the values of 'by-itself-so' and 'alter-intentionality', which come with the unforeseen necessity of accepting elements from other worldviews and of normativity in the procedural VSD approach.Ethics & Philosophy of Technolog
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