1,129 research outputs found

    Enantioselective disposition of (R,R)-formoterol, (S,S)-formoterol and their respective glucuronides in urine following single inhaled dosing and application to doping control

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    Formoterol is a long‐acting beta2‐adrenoceptor agonist (LABA) used for treatment of asthma and exercise‐induced bronchoconstriction. Formoterol is usually administered as a racemic (rac‐) mixture of (R,R)‐ and (S,S)‐enantiomers. While formoterol is restricted by the World Anti‐Doping Agency (WADA), inhalation of formoterol is permitted to a predetermined dose (54 ÎŒg/24 hours) and a urine threshold of 40 ng/mL. However, chiral switch enantiopure (R,R)‐formoterol is available, effectively doubling the therapeutic advantage for the same threshold. The aim of this study was to investigate whether formoterol exhibits enantioselective urinary pharmacokinetics following inhalation. Six healthy volunteers were administered a 12 ÎŒg inhaled dose of rac‐formoterol. Urine was collected over 24‐hours and analysed by enantioselective UPLC‐MS/MS assay. Total (free drug plus conjugated metabolite) median (min‐max) rac‐formoterol urine levels following inhalation were 1.96(1.05‐13.4) ng/mL, 1.67(0.16‐9.67) ng/mL, 0.45(0.16‐1.51) ng/mL, 0.61(0.33‐0.78) ng/mL, and 0.17(0.08‐1.06) ng/mL at 2, 4, 8, 12 and 24 hours, respectively, well below the 2019 urine threshold. The proportion of conjugation differed between enantiomers with glucuronide conjugation much greater for (R,R)‐formoterol (around 30‐60% of total) compared to (S,S)‐formoterol (0‐30%). There was clear evidence of inter‐individual enantioselectivity observed in the ratios of (R,R):(S,S)‐formoterol, where (S,S)‐ was predominant in free formoterol, and (R,R)‐ predominant in the conjugated metabolite. In conclusion, rac‐formoterol delivered by inhalation exhibits enantioselective elimination in urine following single dose administration. Enantioselective assays should be employed in doping control to screen for banned beta2‐agonist chiral switch products such as (R,R)‐formoterol, and total hydrolysed rac‐formoterol is warranted to account for inter‐individual differences in enantioselective glucuronidation

    Beta2-adrenergic ligand racemic formoterol exhibits enantioselective disposition in blood and skeletal muscle of humans, and elicits myocellular protein kinase A-signalling at therapeutic inhaled doses

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    While studies have demonstrated substantial differences in beta2-adrenergic agonist enantiomer pharmacology, enantioselective disposition of long-acting beta2-adrenergic ligand racemic (rac)-formoterol in blood is unexplored after inhaled therapy given analytical challenges. Furthermore, information on enantioselective disposition and partitioning of beta2 -adrenergic agonist in skeletal muscle is absent despite its promising data on muscle anabolism in humans. Using a sensitive UPLC-MS/MS (ultra-high performance liquid chromatography-mass spectrometry) assay, we determined disposition of (R,R)-formoterol and (S,S)-formoterol in plasma and skeletal muscle samples from 11 non-asthmatic men who had inhaled rac-formoterol at therapeutic doses (2×27 ÎŒg). Mean (SD) concentrations of (R,R)- and (S,S)-formoterol in plasma and in muscle biopsies of the vastus lateralis 1 h after inhalation of formoterol were 31 (15) and 45 (18) pg×mL-1 for (R,R)-formoterol and (S,S)-formoterol, respectively, in plasma, and 0.56 (0.32) and 0.51 (0.29) pg×mgwet wt-1, respectively, in muscle. Formoterol exhibited different enantioselective disposition in plasma and muscle (p R,R):(S,S)-formoterol ratio was lower than 0 [-0.17(0.07), p R,R):(S,S)-formoterol ratio was slightly higher than 0 [0.04(0.07), p R,R):(S,S)-formoterol ratio in muscle was related to muscle fibre-type composition. Furthermore, formoterol induced an approximately two-fold increase in muscle p-PKASer/thr phosphorylation (p 2 -adrenergic response. Collectively, these findings suggest that formoterol exhibits modest enantioselective disposition in plasma after inhaled therapy in humans, which appear related to a greater (R,R)-enantiomer disposition in skeletal muscle that may be dependent on fibre-type composition

    Clinical use and efficacy of biphasic insulin lispro 50/50 in people with insulin treated diabetes-A nationwide evaluation of clinical practice

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    © 2015 Informa UK Ltd. Objectives: This study aims to investigate the metabolic effects of biphasic insulin lispro 50/50 in routine clinical practice. A total of 229 patients who were 18 years old with diabetes, newly treated with biphasic insulin lispro 50/50, were sourced from six secondary care services in England. Methods: Detailed clinical parameters were compared at baseline, and 3 and 6 months post-initiation. Responders was defined as those with HbA1c 1% (11mmol/mol) at 6 months. Results: HbA1c showed significant reduction:-0.93% (-10mmol/mol) and-1.2% (-13mmol/mol) at 3 and 6 months respectively, while no significant change was noted for all the other parameters. When analyzed according to frequencies of injections/day, the greatest reduction was observed with the three times a day regimen (-1.0% [-11.0mmol/mol] and-1.3% [-14.6mmol/mol] at 3 and 6 months respectively). HbA1c reduction was greatest in the group who previously received a basal-bolus insulin regimen: (-0.8% [-9.0mmol/mol] and-1.5% [-16.2mmol/mol] at 3 and 6 months respectively). Reduction in weight was observed at 3 months (-1.8kg±4.3) only for those who were previously on a basal-bolus insulin regimen. Insulin doses increased following conversion to biphasic insulin lispro 50/50, irrespective of the types of insulin used prior to biphasic insulin lispro 50/50, but this was not associated with weight gain. The independent predictors of response to biphasic insulin lispro 50/50 were baseline HbA1c, Caucasian, presence of nephropathy, prior use of basal-bolus insulin and prior use of other premixed combination. Conclusion: Biphasic insulin lispro 50/50 is therefore an effective therapeutic option for achieving glycemic control in patients with suboptimal HbA1c levels, especially among those who were previously on a basal-bolus insulin regimen and those who received it three times daily, with a neutral effect on weight parameters. Limitations: This was a retrospective study of routine clinical practice and is therefore limited by allocation bias and some missing data. Information on rates of hypoglycemia and quality of life are not available

    Delay Of Insulin Addition To Oral Combination Therapy Despite Inadequate Glycemic Control: Delay of Insulin Therapy

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    BACKGROUND: Patients and providers may be reluctant to escalate to insulin therapy despite inadequate glycemic control. OBJECTIVES: To determine the proportion of patients attaining and maintaining glycemic targets after initiating sulfonylurea and metformin oral combination therapy (SU/MET); to assess insulin initiation among patients failing SU/MET; and to estimate the glycemic burden incurred, stratified by whether HbA(1c) goal was attained and maintained. DESIGN: Longitudinal observational cohort study. SUBJECTS: Type 2 diabetes patients, 3,891, who newly initiated SU/MET between 1 January 1996 and 31 December 2000. MEASUREMENTS: Subjects were followed until insulin was added, health plan disenrolment, or until 31 December 2005. We calculated the number of months subjects continued SU/MET therapy alone, in total, and during periods of inadequate glycemic control; the A1C reached during those time periods; and total glycemic burden, defined as the estimated cumulative monthly difference between measured A1C and 8%. RESULTS: During a mean follow-up of 54.6 ± 28.6 months, 41.9% of the subjects added insulin, and 11.8% received maximal doses of both oral agents. Over half of SU/MET patients attained but failed to maintain A1C of 8%, yet continued SU/MET therapy for an average of nearly 3 years, sustaining glycemic burden equivalent to nearly 32 months of A1C levels of 9%. Another 18% of patients never attained the 8% goal with SU/MET, yet continued that therapy for an average of 30 months, reaching mean A1C levels of 10%. CONCLUSIONS: Despite inadequate glycemic control, a minority of patients added insulin or maximized oral agent doses, thus, incurring substantial glycemic burden on SU/MET. Additional studies are needed to examine the benefits of rapid titration to maximum doses and earlier initiation of insulin therapy

    Reexamining age, race, site, and thermometer type as variables affecting temperature measurement in adults – A comparison study

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    BACKGROUND: As a result of the recent international vigilance regarding disease assessment, accurate measurement of body temperature has become increasingly important. Yet, trusted low-tech, portable mercury glass thermometers are no longer available. Thus, comparing accuracy of mercury-free thermometers with mercury devices is essential. Study purposes were 1) to examine age, race, site as variables affecting temperature measurement in adults, and 2) to compare clinical accuracy of low-tech Galinstan-in-glass device to mercury-in-glass at oral, axillary, groin, and rectal sites in adults. METHODS: Setting 176 bed accredited healthcare facility, rural northwest US Participants Convenience sample (N = 120) of hospitalized persons ≄ 18 years old. Instruments Temperatures (°F) measured at oral, skin (simultaneous), immediately followed by rectal sites with four each mercury-glass (BD) and Galinstan-glass (Geratherm) thermometers; 10 minute dwell times. RESULTS: Participants averaged 61.6 years (SD 17.9), 188 pounds (SD 55.3); 61% female; race: 85% White, 8.3% Native Am., 4.2% Hispanic, 1.7 % Asian, 0.8% Black. For both mercury and Galinstan-glass thermometers, within-subject temperature readings were highest rectally; followed by oral, then skin sites. Galinstan assessments demonstrated rectal sites 0.91°F > oral and ≅ 1.3°F > skin sites. Devices strongly correlated between and across sites. Site difference scores between devices showed greatest variability at skin sites; least at rectal site. 95% confidence intervals of difference scores by site (°F): oral (0.142 – 0.265), axilla (0.167 – 0.339), groin (0.037 – 0.321), and rectal (-0.111 – 0.111). Race correlated with age, temperature readings each site and device. CONCLUSION: Temperature readings varied by age, race. Mercury readings correlated with Galinstan thermometer readings at all sites. Site mean differences between devices were considered clinically insignificant. Still considered the gold standard, mercury-glass thermometers may no longer be available worldwide. Therefore, mercury-free, environmentally safe low-tech Galinstan-in-glass may be an appropriate replacement. This is especially important as we face new, internationally transmitted diseases

    Braided racks, Hurwitz actions and Nichols algebras with many cubic relations

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    We classify Nichols algebras of irreducible Yetter-Drinfeld modules over groups such that the underlying rack is braided and the homogeneous component of degree three of the Nichols algebra satisfies a given inequality. This assumption turns out to be equivalent to a factorization assumption on the Hilbert series. Besides the known Nichols algebras we obtain a new example. Our method is based on a combinatorial invariant of the Hurwitz orbits with respect to the action of the braid group on three strands.Comment: v2: 35 pages, 6 tables, 14 figure

    Comparative mapping of expressed sequence tags containing microsatellites in rainbow trout (Oncorhynchus mykiss)

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    BACKGROUND: Comparative genomics, through the integration of genetic maps from species of interest with whole genome sequences of other species, will facilitate the identification of genes affecting phenotypes of interest. The development of microsatellite markers from expressed sequence tags will serve to increase marker densities on current salmonid genetic maps and initiate in silico comparative maps with species whose genomes have been fully sequenced. RESULTS: Eighty-nine polymorphic microsatellite markers were generated for rainbow trout of which at least 74 amplify in other salmonids. Fifty-five have been associated with functional annotation and 30 were mapped on existing genetic maps. Homologous sequences were identified for 20 of the EST containing microsatellites to identify comparative assignments within the tetraodon, mouse, and/or human genomes. CONCLUSION: The addition of microsatellite markers constructed from expressed sequence tag data will facilitate the development of high-density genetic maps for rainbow trout and comparative maps with other salmonids and better studied species
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