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Several Doses (several + dose)
Selected AbstractsCorrelation between the residual resistivity ratio and the power-law of the normal-state resistivity in MgB2CRYSTAL RESEARCH AND TECHNOLOGY, Issue 1 2008I. M. Obaidat Abstract MgB2 polycrystalline superconducting specimens were irradiated with several doses of ,-rays up to 100 MR. An increase in the normal state resistivity and a broadening of the resistive transition to the superconducting state were observed with increasing ,-irradiation dose. Although very small changes to the superconducting transition temperature were obtained after ,-irradiation, different temperature dependence of normal-state resistivity and different residual resistivity ratios, RRR were obtained for different doses. We have found a correlation between RRR and the power law dependence of resistivity, n as the irradiation dose increases. This correlation may be an indication that the electron-phonon interaction is important in these samples. These results are attributed to the disorder caused by ,-rays. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Combined exposure to anti-androgens causes markedly increased frequencies of hypospadias in the ratINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 2 2008S. Christiansen Summary The incidence of hypospadias is increasing in young boys, but it remains unclear whether human exposure to endocrine disrupting chemicals plays a role. Risk assessment is based on estimation of no-observed-adverse-effect levels for single compounds, although humans are exposed to combinations of several anti-androgenic chemicals. In a mixture (MIX) study with three androgen receptor antagonists, vinclozolin, flutamide and procymidone, rats were gavaged during gestation and lactation with several doses of a MIX of the three chemicals or the chemicals alone. External malformations of the male reproductive organs were assessed on PND 47 using a score from 0 to 3 (normal to marked) for hypospadias. Markedly increased frequencies were observed after exposure to a MIX of the three chemicals compared to administration of the three chemicals alone. Anogenital distance at PND 1, nipple retention at PND 13, and dysgenesis score at PND 16 were highly correlated with the occurrence of hypospadias, and MIX effects were seen at doses where each of the individual chemicals caused no observable effects. Therefore, the results indicate that doses of anti-androgens, which appear to induce no hypospadias when judged on their own, may induce a very high frequency of hypospadias when they interact in concert with other anti-androgens. [source] Evidence That the Lore-1 Region Specifies Ethanol-Induced Activation in Addition to Sedative/Hypnotic Sensitivity to EthanolALCOHOLISM, Issue 11 2001Jeremy C. Owens Background: Low-dose ethanol-induced activation (LDA) and initial sensitivity to alcohol are both predictors of alcohol abuse in human populations. Our hypothesis is that one or more genes specifying hypnotic sensitivity also specify LDA. We tested this hypothesis by using congenic mice derived from the inbred long-sleep (ILS) and inbred short-sleep (ISS) strains, which carry an ILS region introgressed onto an ISS background. Methods: LDA was assessed by assigning mice randomly to receive one of five doses of ethanol ranging from 1.2 to 2.4 g/kg. On day 1, animals were injected with saline and placed in a brightly lit activity monitor for 30 min, after which they were returned to their home cages. On day 2, mice were injected with ethanol (20% w/v), their activity was monitored for a 30-min period, and LDA was determined by subtracting day 1 activity. The blood ethanol concentration of each animal was then assessed at 30 min by retro-orbital collection of 25 ,l of blood. Results: Ethanol had a significant effect on the activity of ISS mice, but ILS mice showed no activation at any dose, similar to the activities of the outbred lines. All three congenic strains were activated at several doses. Lore-2 and Lore-5 were not ILS-like (less active than ISS) at any dose. In contrast, ISS.ILS- Lore-1 congenics (carrying an ILS-derived Lore-1 allele on the ISS background) were significantly less activated than the ISS controls at 1.8 and 2.4 g/kg of ethanol. Conclusions: The Lore-2 and Lore-5 congenic regions do not affect LDA. In contrast, the Lore-1 congenic region carries one or more genes specifying both initial hypnotic sensitivity to ethanol and LDA. [source] Initial experience with factor-Xa inhibition in percutaneous coronary intervention: the XaNADU-PCI PilotJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 2 2004J. H. Alexander Summary.,Background:,Direct factor (F)Xa inhibition is an attractive method to limit thrombotic complications during percutaneous coronary intervention (PCI). Objectives:,To investigate drug levels achieved, effect on coagulation markers, and preliminary efficacy and safety of several doses of DX-9065a, an intravenous, small molecule, direct, reversible FXa inhibitor during PCI. Patients and methods:,Patients undergoing elective, native-vessel PCI (n = 175) were randomized 4 : 1 to open-label DX-9065a or heparin in one of four sequential stages. DX-9065a regimens in stages I,III were designed to achieve concentrations of >,100 ng mL,1, >,75 ng mL,1, and >,150 ng mL,1. Stage IV used the stage III regimen but included patients recently given heparin. Results:,At 15 min median (minimum) DX-9065a plasma levels were 192 (176), 122 (117), 334 (221), and 429 (231) ng mL,1 in stages I,IV, respectively. Median whole-blood international normalized ratios (INRs) were 2.6 (interquartile range 2.5, 2.7), 1.9 (1.8, 2.0), 3.2 (3.0, 4.1), and 3.8 (3.4, 4.6), and anti-FXa levels were 0.36 (0.32, 0.38), 0.33 (0.26, 0.39), 0.45 (0.41, 0.51), and 0.62 (0.52, 0.65) U mL,1, respectively. Stage II enrollment was stopped (n = 7) after one serious thrombotic event. Ischemic and bleeding events were rare and, in this small population, showed no clear relation to DX-9065a dose. Conclusions:,Elective PCI is feasible using a direct FXa inhibitor for anticoagulation. Predictable plasma drug levels can be rapidly obtained with double-bolus and infusion DX-9065a dosing. Monitoring of DX-9065a may be possible using whole-blood INR. Direct FXa inhibition is a novel and potentially promising approach to anticoagulation during PCI that deserves further study. [source] Effect of new and known 1,4-dihydropyridine derivatives on blood glucose levels in normal and streptozotocin-induced diabetic ratsCELL BIOCHEMISTRY AND FUNCTION, Issue 4 2004na Briede Abstract Analysis of the effect of several 1,4-DHP Ca2+ channel antagonists on experimental and clinical diabetes shows that structurally similar Ca2+ channel antagonists can exert opposite effects on Ca2+ influx, glucose homeostasis and insulin secretion. The influence of the Ca2+ channel antagonists on pancreatic , cell functions is dependent on lipophilicity, interactions with the cell membrane lipid bilayer, with SNAREs protein complexes in cell and vesicle membranes, with intracellular receptors, bioavailability and time of elimination from several organs and the bloodstream. In the present work we studied the effect at several doses of new compounds synthesized in the Latvian Institute of Organic Synthesis on blood glucose levels in normal and STZ-induced diabetic rats. The compounds tested were: 1,4-DHP derivatives cerebrocrast (1), etaftoron (2), OSI-1190 (3), OSI-3802 (4), OSI-2954 (5) and known 1,4-DHP derivatives: niludipine (6), nimodipine (7) and nicardipine (8) which possess different lipophilicities. Analysis of the structure,function relationships of the effect of 1,4-DHP derivatives on glucose metabolism showed that cerebrocrast could evoke qualitative differences in activity. Insertion of an OCHF2 group in position 2 of the 4-phenylsubstituent and propoxyethylgroup R in ester moieties in positions 3 and 5 of the DHP structure, as well as an increase in the number of carbon atoms in the ester moiety, significantly modified the properties of the compound. Thereby cerebrocrast acquired high lipophilicity and membranotropic properties. Cerebrocrast, in a single administration at low doses (0.05 and 0.5,mg,kg,1, p.o.), significantly decreased the plasma level of glucose in normal rats and in STZ-induced diabetic rats returned plasma glucose to basal levels. This effect was characterized by a slow onset and a powerful long-lasting influence on glucose metabolism, especially in STZ-induced diabetic rats. Copyright © 2004 John Wiley & Sons, Ltd. [source] | ||||||||||