Luminescence Dating in Fluvial Settings: Overcoming the Challenge of Partial Bleaching

Optically stimulated luminescence (OSL) dating is a versatile technique that utilises the two most ubiquitous minerals on Earth (quartz or K-feldspar) for constraining the timing of sediment deposition. It has provided accurate ages in agreement with independent age control in many fluvial settings, but is often characterised by partial bleaching of individual grains. Partial bleaching can occur where sunlight exposure is limited and so only a portion of the grains in the sample was exposed to sunlight prior to burial, especially in sediment-laden, turbulent or deep water columns. OSL analysis on multiple grains can provide accurate ages for partially bleached sediments where the OSL signal intensity is dominated by a single brighter grain, but will overestimate the age where the OSL signal intensity is equally as bright (often typical of K-feldspar) or as dim (sometimes typical of quartz). In such settings, it is important to identify partial bleaching and the minimum dose population, preferably by analysing single grains, and applying the appropriate statistical age model to the dose population obtained for each sample. To determine accurate OSL ages using these age models, it is important to quantify the amount of scatter (or overdispersion) in the well-bleached part of the partially bleached dose distribution, which can vary between sediment samples depending upon the bedrock sources and transport histories of grains. Here, we discuss how the effects of partial bleaching can be easily identified and overcome to determine accurate ages. This discussion will therefore focus entirely on the burial dose determination for OSL dating, rather than the dose-rate, as only the burial doses are impacted by the effects of partial bleaching

Pharmacokinetics of moxifloxacin in non-inflamed cerebrospinal fluid of humans: Implication for a bactericidal effect

Objectives: To evaluate the ability of moxifloxacin to penetrate healthy brain barriers. Methods: Fifty patients received a single oral dose of 400 mg as an antimicrobial prophylaxis regimen for a short urological procedure under spinal anaesthesia. Serum and cerebrospinal fluid (CSF) were sampled at different time intervals post-drug intake and patients were divided into five groups, as follows: group I: 0.5-1 h; group II: 1-2 h; group III: 2-4 h; group IV: 4-6 h; and group V: 6-8 h. Concentrations of moxifloxacin were estimated after analysis by an HPLC system. Bactericidal activity of CSF samples of groups III and IV was assessed by a microdilution technique against two penicillin-resistant isolates of Streptococcus pneumoniae with MICs of moxifloxacin of 0.19 and 0.125 mg/L, respectively. Results: Mean CSF concentrations of moxifloxacin of groups I, II, III, IV and V were 0.19, 0.87, 3.00, 4.07 and 1.82 mg/L, respectively. The mean bactericidal activity of CSF of group III was 8 and that of group IV was 4. Conclusions: Single oral intake of 400 mg moxifloxacin is accompanied by good penetration through healthy meninges within 2-6 h post-dose and reached adequately high levels in human CSF exerting satisfactory bactericidal activity against penicillin-resistant S. pneumoniae. These results render novel perspectives for a role of moxifloxacin in CNS infections. © The Author 2008. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved

Cerebrospinal fluid of patients administered moxifloxacin modulates the secretion of cytokines from human monocytes

To evaluate the ex vivo immunomodulatory properties of moxifloxacin, we applied serum and cerebrospinal fluid (CSF) samples from 50 patients who received a single oral dose of 400 mg. Patients were divided into 5 groups according to time lapsing between sampling and drug intake: group I, 0.5 to 1 h; group II, 1 to 2 h; group III, 2 to 4 h; group IV, 4 to 6 h; and group V, 6 to 8 h. Samples were added to cultures of U937 monocytes stimulated by 10 ng/mL of lipopolysaccharide (LPS) and 1 × 105 colony-forming unit (CFU) of 1 heat-killed penicillin-resistant isolate of Streptococcus pneumoniae. Concentrations of cytokines were estimated in supernatants. Concentrations of interleukin (IL)-1β, IL-10, and IL-12 released after stimulation by LPS were significantly decreased by CSF of groups I, IV, and V. After stimulation by the heat-killed isolate, concentrations of tumor necrosis factor α (TNF-α), IL-1β, IL-6, and IL-10 were increased in the presence of CSF of group III; those of IL-12p70 were decreased by CSF of groups I and II. Concentrations of IL-1β, IL-6, and IL-8 drawn after stimulation by LPS were significantly decreased upon addition of serum from all groups. After stimulation by the heat-killed isolate, concentrations of TNF-α were decreased by serum drawn from all patients; IL-1β was increased after addition of serum of groups I, II, and V. It is concluded that CSF and serum of patients administered moxifloxacin may effectively modulate the production of pro- and anti-inflammatory cytokines by human monocytes. These results render new perspectives for the therapy for meningitis. © 2008 Elsevier Inc. All rights reserved

Impact of pregabalin treatment on pain, pain-related sleep interference and general well-being in patients with neuropathic pain: A non-interventional, multicentre, post-marketing study

Background and Objectives: Numerous controlled clinical trials have demonstrated the safety and efficacy of pregabalin in the treatment of neuropathic pain. The objectives of the present study were to assess the impact of pregabalin under real-world conditions on pain, pain-related sleep interference and general well-being, and to assess the tolerability and safety of pregabalin in patients diagnosed with neuropathic pain of central or peripheral origin. Methods: This was a non-interventional, multicentre study in which pregabalin was administered for 8 weeks, at the therapeutic dosages of 150600mg/day, to patients with a diagnosis of neuropathic pain. Pain intensity and pain-related sleep interference were measured using 11-point numerical rating scales, while well-being was assessed by documenting how often emotions associated with anxiety or depression were felt over the past week. Patient and Clinician Global Impression of Change (PGIC and CGIC) were assessed at the final visit. Results: In the 668 patients included in the full analysis set, there were significant (p < 0.0001) reductions in mean pain and pain-related sleep interference scores of 4.16 and 4.02, respectively. Indicators of general well-being showed improvement from baseline to final visit. The majority of patients were rated as much improved (43.7% and 36.7%) or very much improved (24.0% and 26.2%) on CGIC and PGIC scores, respectively. Discontinuation because of lack of efficacy occurred in 0.7% of 691 patients in the safety analysis set while discontinuation because of adverse events occurred in 5.1% of this population; 76.4% continued treatment after the study ended. Conclusion: Significant reductions in pain and pain-related sleep interference, combined with reductions in feelings of anxiety and depression, suggest that pregabalin under real-world conditions improves the overall health and wellbeing of patients with neuropathic pain. © 2011 Adis Data Information BV. All rights reserved

Impact of pregabalin treatment on pain, pain-related sleep interference and general well-being in patients with neuropathic pain: A non-interventional, multicentre, post-marketing study

Background and Objectives: Numerous controlled clinical trials have demonstrated the safety and efficacy of pregabalin in the treatment of neuropathic pain. The objectives of the present study were to assess the impact of pregabalin under real-world conditions on pain, pain-related sleep interference and general well-being, and to assess the tolerability and safety of pregabalin in patients diagnosed with neuropathic pain of central or peripheral origin. Methods: This was a non-interventional, multicentre study in which pregabalin was administered for 8 weeks, at the therapeutic dosages of 150600mg/day, to patients with a diagnosis of neuropathic pain. Pain intensity and pain-related sleep interference were measured using 11-point numerical rating scales, while well-being was assessed by documenting how often emotions associated with anxiety or depression were felt over the past week. Patient and Clinician Global Impression of Change (PGIC and CGIC) were assessed at the final visit. Results: In the 668 patients included in the full analysis set, there were significant (p < 0.0001) reductions in mean pain and pain-related sleep interference scores of 4.16 and 4.02, respectively. Indicators of general well-being showed improvement from baseline to final visit. The majority of patients were rated as much improved (43.7% and 36.7%) or very much improved (24.0% and 26.2%) on CGIC and PGIC scores, respectively. Discontinuation because of lack of efficacy occurred in 0.7% of 691 patients in the safety analysis set while discontinuation because of adverse events occurred in 5.1% of this population; 76.4% continued treatment after the study ended. Conclusion: Significant reductions in pain and pain-related sleep interference, combined with reductions in feelings of anxiety and depression, suggest that pregabalin under real-world conditions improves the overall health and wellbeing of patients with neuropathic pain. © 2011 Adis Data Information BV. All rights reserved