Search

Methadone has two enantiomers, which exhibit differences in pharmacological effects, with R-methadone being the active and S-methadone the inactive enantiomer. A robust, simple and rapid method for chiral separation of the two enantiomers in serum samples using ultra-high performance supercritical fluid chromatography-tandem mass spectrometry (UHPSFC-MSMS) has been developed and validated. Enantiomeric separation was achieved using a Chiralpak IH-3 column with a mobile phase consisting of CO 2 and 30mM ammonium acetate in methanol/water (98/2, v/v). Runtime was 4 minutes. Sample preparation was semi-automated using a Hamilton ML Star robot with protein precipitation, and phospholipid removal was carried out using a Waters OSTRO™ 96-well plate. The calibration range was 50.0-1,500 nM for each enantiomer. The between-assay relative standard deviations were in the range of 1.2-3.6%. Matrix effects ranged from 99% to 115% corrected with internal standard. The method has been implemented in our laboratory and has proven to be a robust and reliable method for determining the ratio of R/S-methadone in authentic patient samples., (© 2024 The Authors. Drug Testing and Analysis published by John Wiley & Sons Ltd.)

Data on marine biota exist in many formats and sources, such as published literature, data repositories, and unpublished material. Due to this heterogeneity, information is difficult to find, access and combine, severely impeding its reuse for further scientific analysis and its long-term availability for future generations. To address this challenge, we present CRITTERBASE, a publicly accessible data warehouse and interactive portal that currently hosts quality-controlled and taxonomically standardized presence/absence, abundance, and biomass data for 18,644 samples and 3,664 benthic taxa (2,824 of which at species level). These samples were collected by grabs, underwater imaging or trawls in Arctic, North Sea and Antarctic regions between the years 1800 and 2014. Data were collated from literature, unpublished data, own research and online repositories. All metadata and links to primary sources are included. We envision CRITTERBASE becoming a valuable and continuously expanding tool for a wide range of usages, such as studies of spatio-temporal biodiversity patterns, impacts and risks of climate change or the evidence-based design of marine protection policies., (© 2022. The Author(s).)

The amphetamine molecule contains a chiral center and its enantiomers exhibit differences in pharmacological effects, with the S-enantiomer mediating most of the central nervous system stimulating activity. The majority of prescribed amphetamine consists of the pure S-enantiomer, but therapeutic formulations containing the R-enantiomer in various proportions are also available. Illegal amphetamine remains available mainly as a racemic mixture of the R- and S-enantiomers. To distinguish between legal and illegal consumption of amphetamine a method for enantiomeric separation and quantification of R/S-amphetamine in serum was developed and validated using ultra-high performance supercritical fluid chromatography-tandem mass spectrometry (UHPSFC-MS/MS). Sample preparation prior to UHPSFC-MS/MS analysis was performed by a semi-automated liquid-liquid extraction method. The UHPSFC-MS/MS method used a Chiralpak AD-3 column with a mobile phase consisting of CO 2 and 0.1% ammonium hydroxide in 2-propanol/methanol (50/50, v/v). The injection volume was 2 μL and run time was 4 minutes. MS/MS detection was performed with positive electrospray ionization and two multiple reaction monitoring transitions (m/z 136.1 > 119.0 and m/z 136.1 > 91.0). The calibration range was 12.5-1,000 nM for each analyte. The between-assay relative standard deviations were in the range of 1.3-3.0%. Recovery was 73% and matrix effects ranged from 95 to 100% when corrected with internal standard. After development and validation, the method has been successfully implemented in our laboratory for both separation and quantification of R/S-amphetamine and has proved to be a reliable and useful tool for distinguishing intake of R- and S-amphetamine in authentic patient samples., (© 2020 John Wiley & Sons, Ltd.)

Objective: To develop and evaluate an interactive histology learning software for medical students in the preclinical study phase. The educational design of the software was based on current learning theory models, such as the Cognitive load theory, Cognitive theory of multimedia learning , and the ARCS model, so that the acquired knowledge can be repeated using a diversified design. Moreover, the learning effects achieved by using the software shall be evaluated. Apart from the software's usability, the influence of the learning theory principles on the students' motivation shall be assessed. Methodology: The software was evaluated using an experimental wait list control group with a pre-/post-test design (n=213). Depending on the group they were assigned to, students learned the histology contents of chapter "Liver, gall bladder, pancreas" using the traditional program of the Goethe University (n=65), the new interactive software (n=56), or without any of the two software versions (n=92). The influence of the different learning aids on the acquisition of knowledge was assessed with three questionnaires comprising four different multiple choice questions each. For the evaluation of the usability and motivational factors, a second test was added to the questionnaire of both software versions. Results: The interactive software was rated significantly better with regard to usability and motivational aspects than the traditional learning program ( F (7, 113)=12.48, p <.001, partial η 2 =.436). Moreover, use of the interactive software resulted in a significant increase of knowledge acquisition as compared to the group of students who had learned without any of the two software versions (0.77, p =.001). Conclusion: With regard to the histology contents, usability was comparable to the official learning program. Interactive elements and the educational design contributed to an increase of the factors that are essential for intrinsic motivation. Thus, our program can be valuable tool to supplement the curriculum as an additional service., Competing Interests: The authors declare that they have no competing interests., (Copyright © 2020 Drees et al.)

In 2011, we reported that our paediatric asthma clinic (PAC) appeared to significantly reduce the burden of paediatric asthma in our community. Supported by these results, the PAC underwent a gradual threefold expansion while maintaining the same model of care. We now report on the outcome of that expansion and demonstrate that our PAC continues to significantly reduce the burden of paediatric asthma in our community. As previously, newly enrolled PAC patients continue to show a 12-month reduction in asthma-related emergency department (ED) visits and admissions exceeding 60% and 80%, respectively. This consistent short-term benefit, coupled with clinic expansion, has contributed to a significant improvement in our rate of paediatric asthma-related ED visits or hospitalizations when compared to other Ontario hospitals.

Background: It is still unclear to what extent the PBL tutor affects learning in PBL-sessions. This mixed-methods study (Part 1 and 2) evaluated the effects of facilitative (f) versus non-facilitative (nf) tutoring roles on knowledge-gain and group functioning in the field of endodontics., Methods: Part 1 was a quantitative assessment of tutor effectiveness within a prospective, experimental, single-blind, stratified, randomized, two-group intervention study. Participants attended PBL in the context of a hybrid curriculum. A validated questionnaire was used and knowledge assessments were conducted before and after the intervention. External observers rated tutor performance. Part 2 was a qualitative assessment of tutor effectiveness and consisted of semi-structured expert interviews with tutors and focus group discussions with students., Results: Part 1: f tutors obtained significantly higher scores than nf tutors with respect to learning motivation and tutor effectiveness (p ≤ 0.05). nf tuition resulted in a slightly larger knowledge gain (p = 0.08). External observers documented a significantly higher activity among facilitative tutors compared to non-facilitative tutors. Part 2: Tutors found the f role easier although this led to a less autonomous working climate. The students rated f tutoring as positive in all cases., Conclusions: With respect to PBL-group performance, students felt that groups guided in a non-facilitative fashion exhibited a higher level of independence and autonomy, especially with increasing PBL experience. In addition, students reported that more preparation was necessary for sessions guided by a non-facilitative tutor. Tutors were able to modify their role and influence group processes in a controlled manner. Results are useful for future "Train-the-Teacher" sessions.

This study describes the pharmacokinetics of mycophenolate mofetil (MMF) in 15 pediatric patients with vasculitis and connective tissue disease involving the kidney. Patients included 10 with systemic lupus erythematosus (SLE), 1 with antiphospholipid antibody syndrome, 2 with Wegener granulomatosis, and 1 each with Goodpasture syndrome, Henoch-Schönlein-associated nephritis, and 1 with severe tubulointerstitial nephritis and uveitis. All patients were treated with steroids and additional therapy prior to treatment with MMF, which was administered for a median of 491 days. Mean starting dose of MMF was 974+/-282 mg/m(2 )in two divided doses. Pharmacokinetic monitoring of the active compound of MMF, mycophenolic acid (MPA), was performed using an EMIT assay. The mean MPA AUC after a median of 39 days was 61.8+/-31.0 micro gxh/ml, median time to maximum concentration was 60 min, and mean maximum concentration was 18.5+/-8.4 micro g/ml. At last follow-up, mean MMF dose was 900+/-341 mg/m(2) per day, and mean trough MPA concentration was 3.1+/-1.1 (range 0.6-4.6) micro g/ml. Therapy was effective in inducing remission in 4 of 9 patients with active disease. Only 1 of the 5 other patients relapsed. All 6 patients with controlled disease maintained remission. There were few side effects: one episode each of diarrhea and leukocytopenia and two viral infections. We conclude that MMF at 900 mg/m(2) per day appears to be effective in these patients.