65 research outputs found

    The Metallicity-Luminosity Relation, Effective Yields, and Metal Loss in Spiral and Irregular Galaxies

    Full text link
    I present results on the correlation between galaxy mass, luminosity, and metallicity for a sample of spiral and irregular galaxies having well-measured abundance profiles, distances, and rotation speeds. Additional data for low surface brightness galaxies from the literature are also included for comparison. These data are combined to study the metallicity-luminosity and metallicity-rotation speed correlations for spiral and irregular galaxies. The metallicity luminosity correlation shows its familiar form for these galaxies, a roughly uniform change in the average present-day O/H abundance of about a factor 100 over 11 magnitudes in B luminosity. However, the O/H - V(rot) relation shows a change in slope at a rotation speed of about 125 km/sec. At faster V(rot), there appears to be no relation between average metallicity and rotation speed. At lower V(rot), the metallicity correlates with rotation speed. This change in behavior could be the result of increasing loss of metals from the smaller galaxies in supernova-driven winds. This idea is tested by looking at the variation in effective yield, derived from observed abundances and gas fractions assuming closed box chemical evolution. The effective yields derived for spiral and irregular galaxies increase by a factor of 10-20 from V(rot) approximately 5 km/sec to V(rot) approximately 300 km/sec, asympotically increasing to approximately constant y(eff) for V(rot) > 150 km/sec. The trend suggests that galaxies with V(rot) < 100-150 km/sec may lose a large fraction of their SN ejecta, while galaxies above this value tend to retain metals.Comment: 40 pages total, including 7 encapsulated postscript figures. Accepted for publication in 20 Dec 2002 Ap

    Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

    Get PDF
    Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

    Assumption without representation: the unacknowledged abstraction from communities and social goods

    Get PDF
    We have not clearly acknowledged the abstraction from unpriceable “social goods” (derived from communities) which, different from private and public goods, simply disappear if it is attempted to market them. Separability from markets and economics has not been argued, much less established. Acknowledging communities would reinforce rather than undermine them, and thus facilitate the production of social goods. But it would also help economics by facilitating our understanding of – and response to – financial crises as well as environmental destruction and many social problems, and by reducing the alienation from economics often felt by students and the public

    Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

    Get PDF
    Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

    Hypocomplementemic interstitial nephritis with long-term follow-up

    No full text
    Prednisone-sensitive hypocomplementemia, renal insufficiency, and kidney biopsy demonstrating severe tubulointerstitial nephritis (TIN), storiform fibrosis, and tubulointerstitial immune deposits are typical of IgG4-related tubulointerstitial nephritis and hypocomplementemic interstitial nephritis. A diagnosis of hypocomplementemic interstitial nephritis requires clinical and pathologic exclusion of IgG4-related tubulointerstitial nephritis. We describe a patient with hypocomplementemic interstitial nephritis who did not develop diagnostic features of IgG4 related disease (RD) over 2-year follow-up. We conclude that hypocomplementemic interstitial nephritis could be on a biologic spectrum with IgG4-related disease, but not all cases will develop the abundance of IgG4-positive plasma cells, systemic manifestations, or elevated immunoglobulin levels characteristic of IgG4-RD

    Comparison of acute rapamycin nephrotoxicity with cyclosporine and FK506

    Get PDF
    Comparison of acute rapamycin nephrotoxicity with cyclosporine and FK506. Acute cyclosporine (CsA) nephrotoxicity is characterized by a reduction of glomerular filtration rate (GFR), hypomagnesemia and tubular injury. The mechanisms of CsA's immunosuppressive action and presumably its nephrotoxicity are mediated through inhibition of the renal phosphatase, calcineurin. FK506 (FK), which has a different chemical structure and binding immunophilin, also inhibits calcineurin. We compared the renal effects of these drugs to those of rapamycin (RAPA), which although similar in structure and intracellular binding to FK, does not work by changing calcineurin activity. Rats were given CsA (15 mg/kg/s.c), FK (6 mg/kg/p.o.), RAPA (3 mg/kg/p.o.) or vehicle (V) for two weeks on a low salt diet. CsA and FK strikingly decreased urinary excretion of nitric oxide, renal blood flow and GFR, whereas RAPA did not. In contrast, all these three drugs caused significant hypomagnesemia associated with inappropriately high fractional excretion of magnesium, suggesting renal magnesium wasting. In addition, with all three drugs there were lesions in the rat kidneys consisting of tubular collapse, vacuolization and nephrocalcinosis. We thus showed that only the calcineurin inhibitors produced glomerular dysfunction in an acute experimental model of nephrotoxicity. The mechanism of hypomagnesemia and tubular injury induced by all three immunosuppressive drugs is unclear but may be independent of calcineurin. The mechanism of renal vasoconstriction on the other hand may be related to inhibition of calcineurin

    Buyer beware? : does the information provided with herbal products available over the counter enable safe use?

    Get PDF
    Background: Herbal products obtained over the counter are commonly used in Europe, North America and Australia. Although there is concern about a lack of information provided to consumers to allow the safe use of these products, there has been no published research to confirm these fears. In this study, we evaluated written information provided with commonly used herbal products in the UK in advance of a European Union Directive issued in April 2011 that tightened regulations for some herbal products, including requirements to provide safety information. Methods: Five commonly used herbal products were purchased from pharmacies, health food shops and supermarkets: St John’s wort, Asian ginseng, echinacea, garlic and ginkgo. Written information provided with the products (on the package or on a leaflet contained in the package) was evaluated for inclusion of each of the key safety messages included in the monographs of the US National Center for Complementary and Alternative Medicine. Specifically, we looked for information on precautions (such as Asian ginseng not being suitable for people with diabetes), interactions with conventional medicines (such as St John’s wort with the contraceptive pill and warfarin) and side effects (such as ginkgo and allergic reactions). Results: Our analysis showed that, overall, 51 (75%) of 68 products contained none of the key safety messages. This included 4 of 12 St John’s wort products, 12 of 12 ginkgo products, 6 of 7 Asian ginseng products, 20 of 21 garlic products and 9 of 13 echinacea products. The two products purchased that are registered under the new European Union regulations (for St John’s wort) contained at least 85% of the safety messages. Conclusions: Most of the herbal medicine products studied did not provide key safety information which consumers need for their safe use. The new European Union legislation should ensure that St John’s wort and echinacea products will include the previously missing information in due course. The legislation does not apply to existing stock. Depending on therapeutic claims made by manufacturers, garlic, ginkgo and Asian ginseng products may not be covered by the legislation and can continue to be bought without the safety information. Also, consumers will still be able to buy products over the internet from locations outside European Union jurisdiction. Potential purchasers need to know, in both the short term and the long term, how to purchase herbal products which provide the information they need for the safe use of these products

    Experimental Gentamicin Nephrotoxicity: Effect of Streptozotocin-Induced Diabetes&apos;

    No full text
    ABSTRACT Methods Three-month-old Fischer 344 rats were obtained from Simonsen Laboratories (Gilroy, CA). All animals were provided standard rat chow ABBREVIATIONS: CCR, creatinine clearance; SCR, serum creatinine; GFR, glomerular filtration rate; CN, inulin clearance; PAH, p-aminohippurate
    • …
    corecore