30 results on '"T. Kraemer"'
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2. Societal Factors that Impact Retention and Graduation of Underrepresented Computer Science Undergraduates.
- Author
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Oluwafemi Osho, Bart P. Knijnenburg, Eileen T. Kraemer, Cazembe Kennedy, Gloria J. Washington, Stacey Sexton, John Porter, and Kinnis Gosha
- Published
- 2023
- Full Text
- View/download PDF
3. Home-based ambulatory video EEG monitoring: a cost-effective and underutilised diagnostic tool for people with seizure disorders in Australia.
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Seneviratne U, Gillinder L, Kraemer T, Lee A, and Bower S
- Published
- 2024
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4. Comprehensive evaluation of cocaine and its hydroxy metabolites in seized cocaine and a large cohort of hair samples.
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Madry MM, Denifle T, Binz TM, Bogdal C, Kraemer T, and Baumgartner MR
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- Humans, Male, Female, Cohort Studies, Hair chemistry, Cocaine analogs & derivatives, Cocaine analysis, Cocaine metabolism, Substance Abuse Detection methods
- Abstract
As cocaine (COC) is not only incorporated into hair via blood following ingestion but also by external contamination, hair samples are commonly tested for COC metabolites to prove ingestion. However, COC metabolites can also be present as degradation products in typical street COC samples. The present study investigates minor hydroxycocaine (OH-COC) metabolites p- and m-OH-COC together with p- and m-hydroxybenzoylecgonine (OH-BE) in seized COC (n = 200) and hair samples from routine case work (n = 2389). Analytical results of hair samples were interpreted using an established decision model for the differentiation between actual use and external contamination using metabolic ratios (metabolite to COC). They were further examined concerning background of request, hair color, body site of sample collection, sex, and metabolic ratios of the main metabolites [benzoylecgonine (BE), norcocaine (NC), and cocaethylene (CE)]. All seized COC samples were positive for p- and m-OH-COC with a maximum percentage of 0.025% and 0.052%, respectively; p- and m-OH-BE were detected in 55% and 56% of samples with a maximum percentage of 0.044% and 0.024%, respectively. Analytical results of 424 hair samples (17.7%) were interpreted as being predominantly from contamination; the majority of these samples were from traffic medicine cases (83.7%). Metabolic ratios of minor OH-COC metabolites were significantly higher in hair samples interpreted as originating from use than in samples interpreted as caused by contamination. Metabolic ratios for OH-COCs were significantly higher in forensic cases compared to abstinence controls and also in black hair compared to blond/gray hair. However, this was not the case for OH-BE metabolic ratios. No statistical difference was observed with regard to the donor's sex. OH-COC metabolic ratios increased significantly with increasing ratios of NC and CE to COC, respectively. The study demonstrates that OH-COC metabolites (including thresholds for their metabolic ratios) must be used for a reliable interpretation of positive COC results in hair samples., (© The Author(s) 2024. Published by Oxford University Press.)
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- 2024
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5. Multianalyte Approach-Including Automated Preparation of Calibrators-for Validated Quantification of 82 Drugs in Whole Blood by Liquid Chromatography-Tandem Mass Spectrometry.
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Steuer AE, Keller M, Kraemer T, and Poetzsch SN
- Abstract
Bioanalysis, such as the quantification of drugs in different matrices, is of great importance in forensic toxicology. Nowadays, mainly so-called multianalyte approaches are used given their increased speed and effectiveness. However, such multianalyte procedures can be difficult to develop and maintain with sufficient robustness in the laboratory. One aspect of this is the tedious, manual preparation of spiking solutions containing such a great number of analytes. Therefore, the current study aimed to develop and validate a fast, simple, and robust liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of 82 classic drugs and to evaluate an alternative autosampler-assisted automated approach for the preparation of spiking solutions. Simple protein precipitation of 200-μL whole blood was used followed by analysis by reversed-phase LC-MS/MS in advanced scheduled multiple reaction monitoring (MRM) mode. The method was fully validated according to international guidelines, including selectivity, recovery, matrix effects, linearity, bias/imprecision, processed-sample stability, and limits. Validation criteria were fulfilled for all analytes except for buprenorphine and five benzodiazepines. In the context of a multianalyte procedure, a (multipurpose) autosampler-assisted automatic preparation of calibrator spiking solutions proved comparable to manual preparation. Thus, automated preparation can overcome the frequently performed manual, time-consuming, and error-prone steps of multianalyte approaches and still allow for customized calibration ranges. Since its introduction, more than 8000 cases have been measured with the presented method, and 35 proficiency tests have been passed., (© 2024 The Author(s). Drug Testing and Analysis published by John Wiley & Sons Ltd.)
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- 2024
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6. Impact of three different peak picking software tools on the quality of untargeted metabolomics data.
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Wartmann Y, Boxler MI, Kraemer T, and Steuer AE
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- Reproducibility of Results, Quality Control, Software, Metabolomics methods
- Abstract
Data quality and control parameters are becoming more important in metabolomics. For peak picking, open-source or commercial solutions are used. Other publications consider different software solutions or data acquisition types for peak picking, a combination, including proposed and new quality parameters for the process of peak picking, does not exist. This study tries to examine the performance of three different software in terms of reproducibility and quality of their output while also considering new quality parameters to gain a better understanding of resulting feature lists in metabolomics data. We saw best recovery of spiked analytes in MS-DIAL. Reproducibility over multiple projects was good among all software. The total number of features found was consistent for DDA and full scan acquisition in MS-DIAL but full scan data leading to considerably more features in MZmine and Progenesis Qi. Feature linearity proved to be a good quality parameter. Features in MS-DIAL and MZmine, showed good linearity while Progenesis Qi produced large variation, especially in full scan data. Peak width proved to be a very powerful filtering criteria revealing many features in MZmine and Progenesis Qi to be of questionable peak width. Additionally, full scan data appears to produce a disproportionally higher number of short features. This parameter is not yet available in MS-DIAL. Finally, the manual classification of true positive features proved MS-DIAL to perform significantly better in DDA data (62 % true positive) than the two other software in either mode. We showed that currently popular solutions MS-DIAL and MZmine perform well in targeted analysis of spiked analytes as well as in classic untargeted analysis. The commercially available solution Progenesis Qi does not hold any advantage over the two in terms of quality parameters, of which we proposed peak width as a new parameter and showed that already proposed parameters such as feature linearity in samples of increasing concentration are advisable to use., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
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- 2024
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7. Assessing the influence of sleep and sampling time on metabolites in oral fluid: implications for metabolomics studies.
- Author
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Scholz M, Steuer AE, Dobay A, Landolt HP, and Kraemer T
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- Humans, Male, Young Adult, Adult, Sleep Deprivation metabolism, Metabolome physiology, Time Factors, Metabolomics methods, Saliva metabolism, Saliva chemistry, Sleep physiology
- Abstract
Introduction: The human salivary metabolome is a rich source of information for metabolomics studies. Among other influences, individual differences in sleep-wake history and time of day may affect the metabolome., Objectives: We aimed to characterize the influence of a single night of sleep deprivation compared to sufficient sleep on the metabolites present in oral fluid and to assess the implications of sampling time points for the design of metabolomics studies., Methods: Oral fluid specimens of 13 healthy young males were obtained in Salivette
® devices at regular intervals in both a control condition (repeated 8-hour sleep) and a sleep deprivation condition (total sleep deprivation of 8 h, recovery sleep of 8 h) and their metabolic contents compared in a semi-targeted metabolomics approach., Results: Analysis of variance results showed factor 'time' (i.e., sampling time point) representing the major influencer (median 9.24%, range 3.02-42.91%), surpassing the intervention of sleep deprivation (median 1.81%, range 0.19-12.46%). In addition, we found about 10% of all metabolic features to have significantly changed in at least one time point after a night of sleep deprivation when compared to 8 h of sleep., Conclusion: The majority of significant alterations in metabolites' abundances were found when sampled in the morning hours, which can lead to subsequent misinterpretations of experimental effects in metabolomics studies. Beyond applying a within-subject design with identical sample collection times, we highly recommend monitoring participants' sleep-wake schedules prior to and during experiments, even if the study focus is not sleep-related (e.g., via actigraphy)., (© 2024. The Author(s).)- Published
- 2024
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8. Do dried blood spots have the potential to support result management processes in routine sports drug testing?-Part 3: LC-MS/MS-based peptide analysis for dried blood spot sampling time point estimation.
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Brockbals L, Thomas A, Schneider TD, Kraemer T, Steuer AE, and Thevis M
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- Humans, Chromatography, Liquid methods, Time Factors, Male, Specimen Handling methods, Adult, Liquid Chromatography-Mass Spectrometry, Dried Blood Spot Testing methods, Doping in Sports prevention & control, Tandem Mass Spectrometry methods, Substance Abuse Detection methods, Peptides blood, Peptides analysis
- Abstract
Along with the recent acknowledgement of the World Anti-Doping Agency to use dried blood spot (DBS) samples for routine doping control purposes, there have been propositions to use DBS as a matrix that allows regular proactive remotely supervised self-sampling, providing potential longitudinal monitoring of an athlete's exposure to doping agents. However, several organizational aspects have to be considered before implementation, such as the verification of the sample collections time point. Based on a previous untargeted proteomics workflow utilizing liquid chromatography-high-resolution mass spectrometry (LC-HRMS) to identify protein/peptide markers to define the time since deposition of a bloodstain, the aim of the current study was to develop a targeted LC-HRMS/MS analytical method for promising peptidic target analytes. A long-term DBS storage experiment was carried out over a 3-month period (sample collection time points: 0, 2, 4, 7, 14, 21, 28, 42, 56, 70, 84 and 91 days) with DBS samples of 10 volunteers for longitudinal investigation of signal abundance changes of targeted peptide sequences at different storage temperatures (room temperature [RT], 4°C and -20°C). Prior to experimental analysis, LC-HRMS/MS method characteristics were successfully assessed, including intraday precision, carryover and sample extract stability. For estimation of DBS sample collection time points, ratios of two peptides that originate from the same protein prior to tryptic digestion were created. Two targeted peptide area ratios were found to significantly increase after being stored at RT for 28 days, representing potential markers for future use in routine doping controls that contribute to advancing complementary avenues in anti-doping., (© 2023 The Authors. Drug Testing and Analysis published by John Wiley & Sons Ltd.)
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- 2024
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9. Delirium in Neurocritical Care: Uncovering Undisclosed Psychotropic Substance and Medication Use and Stress Exposure by Hair Analysis.
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Bögli SY, Capone C, Baumgartner MR, Quednow BB, Kraemer T, Keller E, and Binz TM
- Abstract
Objective: In intensive care, delirium is frequent, prolongs the stay, increases health care costs, and worsens patient outcome. Several substances and medications as well as stress can impact the risk of delirium; however, assessment of previous exposure to psychotropic agents and stress by self-reports or third-party information is not always reliable. Hair analysis can be used to objectively assess medication and substance use (including chronic alcohol consumption), and allows for the determination of stress-related long-term changes in steroid hormones and endocannabinoids., Methods: Consecutive adult patients with acute brain injury admitted to the neurocritical care unit were included. Delirium was diagnosed using the Confusion Assessment Method for the Intensive Care Unit. Liquid chromatography coupled with tandem mass spectrometry was used to investigate psychoactive substances and medications, ethyl glucuronide, steroid hormones, and endocannabinoids in hair samples. Univariable and multivariable analyses were used to reveal any associations with the occurrence of delirium., Results: Of 50 consecutive patients, 21 (42%) were diagnosed with delirium. Detection of antipsychotics or antidepressants in hair was more frequent in patients with delirium (antidepressants: 43% vs. 14%, p = 0.040; antipsychotics: 29% vs. 0%, p = 0.021). These patients also displayed higher ethyl glucuronide levels (p = 0.049). Anandamide (AEA) concentrations were higher in patients with delirium (p = 0.005), whereas oleoylethanolamide (p = 0.045) and palmitoylethanolamide (PEA) (p = 0.017) concentrations were lower in patients with delirium. Backward stepwise logistic regression analysis revealed antidepressants and AEA/PEA to be independent relevant predictors of delirium., Conclusions: Hair analysis provides crucial and otherwise unattainable information regarding chronic stress and the use of psychotropic substances and medications. Undisclosed antidepressant/antipsychotic use or intense chronic alcohol consumption is susceptible to treatment (continuation of medication or provision of low-dose benzodiazepines in case of alcohol). Chronic stress can be evaluated using stress markers and endocannabinoids in hair, potentially allowing for personalized delirium risk stratification and preventive measures., (© 2024. The Author(s).)
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- 2024
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10. Postmortem metabolomics: influence of time since death on the level of endogenous compounds in human femoral blood. Necessary to be considered in metabolome study planning?
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Steuer AE, Wartmann Y, Schellenberg R, Mantinieks D, Glowacki LL, Gerostamoulos D, Kraemer T, and Brockbals L
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- Humans, Male, Female, Middle Aged, Adult, Aged, Autopsy, Aged, 80 and over, Time Factors, Amino Acids metabolism, Amino Acids blood, Young Adult, Metabolomics methods, Postmortem Changes, Metabolome
- Abstract
Introduction: The (un)targeted analysis of endogenous compounds has gained interest in the field of forensic postmortem investigations. The blood metabolome is influenced by many factors, and postmortem specimens are considered particularly challenging due to unpredictable decomposition processes., Objectives: This study aimed to systematically investigate the influence of the time since death on endogenous compounds and its relevance in designing postmortem metabolome studies., Methods: Femoral blood samples of 427 authentic postmortem cases, were collected at two time points after death (854 samples in total; t1: admission to the institute, 1.3-290 h; t2: autopsy, 11-478 h; median ∆t = 71 h). All samples were analyzed using an untargeted metabolome approach, and peak areas were determined for 38 compounds (acylcarnitines, amino acids, phospholipids, and others). Differences between t2 and t1 were assessed by Wilcoxon signed-ranked test (p < 0.05). Moreover, all samples (n = 854) were binned into time groups (6 h, 12 h, or 24 h intervals) and compared by Kruskal-Wallis/Dunn's multiple comparison tests (p < 0.05 each) to investigate the effect of the estimated time since death., Results: Except for serine, threonine, and PC 34:1, all tested analytes revealed statistically significant changes between t1 and t2 (highest median increase 166%). Unpaired analysis of all 854 blood samples in-between groups indicated similar results. Significant differences were typically observed between blood samples collected within the first and later than 48 h after death, respectively., Conclusions: To improve the consistency of comprehensive data evaluation in postmortem metabolome studies, it seems advisable to only include specimens collected within the first 2 days after death., (© 2024. The Author(s).)
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- 2024
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11. Influence of Blood Components on Neuroinflammation, Blood-Brain Barrier Breakdown, and Functional Damage After Acute Subdural Hematoma in Rats.
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Jussen D, Saeed S, Jablonski T, Krenzlin H, Lucia K, Kraemer T, Kempski O, Czabanka M, Ringel F, and Alessandri B
- Abstract
A central component of injury development after acute subdural hematoma (ASDH) is the increased intracranial pressure and consecutive mechanical reduction of cerebral blood flow (CBF). However, the role of different blood constituents in ASDH as additional lesioning factors remains unclear. This study examines the influence of blood components on neuroinflammation, blood-brain barrier (BBB) breakdown, and functional deficits in a rat model of ASDH. We infused corpuscular (whole blood, whole blood lysate, and red cell blood) and plasmatic (blood plasma, anticoagulated blood plasma, and aqueous isotonic solution) blood components into the subdural space while CBF was monitored. Rats then underwent behavioral testing. Lesion analysis and immunohistochemistry were performed 2 days after ASDH. Inflammatory reaction was assessed using staining for ionized calcium-binding adaptor molecule 1 and glial fibrillary acidic protein, interleukin-1ß, tumor necrosis factor-alpha, and membrane attack complex. Integrity of the BBB was evaluated with albumin and matrix metalloproteinase 9 (MMP9) staining. We observed a significant drop in CBF in the corpuscular group (75% ± 7.5% of baseline) with distinct post-operative deficits and larger lesion volume compared to the plasmatic group (13.6 ± 5.4 vs. 1.3 ± 0.4 mm
3 ). Further, inflammation was significantly increased in the corpuscular group with stronger immunoreaction. After whole blood infusion, albumin and MMP9 immunoreaction were significantly increased, pointing toward a disrupted BBB. The interaction between corpuscular and plasmatic blood components seems to be a key factor in the detrimental impact of ASDH. This interaction results in neuroinflammation and BBB leakage. These findings underscore the importance of performing surgery as early as possible and also provide indications for potential pharmacological targets., Competing Interests: No competing financial interests exist., (© Daniel Jussen et al., 2024; Published by Mary Ann Liebert, Inc.)- Published
- 2024
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12. Factors influencing the successful implementation of a novel digital health application to streamline multidisciplinary communication across multiple organisations for emergency care.
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Bagot KL, Bladin CF, Vu M, Bernard S, Smith K, Hocking G, Coupland T, Hutton D, Badcock D, Budge M, Nadurata V, Pearce W, Hall H, Kelly B, Spencer A, Chapman P, Oqueli E, Sahathevan R, Kraemer T, Hair C, Dion S, McGuinness C, and Cadilhac DA
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- Humans, Digital Health, Australia, Delivery of Health Care, Interdisciplinary Communication, Emergency Medical Services
- Abstract
Rationale: Delivering optimal patient health care requires interdisciplinary clinician communication. A single communication tool across multiple pre-hospital and hospital settings, and between hospital departments is a novel solution to current systems. Fit-for-purpose, secure smartphone applications allow clinical information to be shared quickly between health providers. Little is known as to what underpins their successful implementation in an emergency care context., Aims: To identify (a) whether implementing a single, digital health communication application across multiple health care organisations and hospital departments is feasible; (b) the barriers and facilitators to implementation; and (c) which factors are associated with clinicians' intentions to use the technology., Methods: We used a multimethod design, evaluating the implementation of a secure, digital communication application (Pulsara™). The technology was trialled in two Australian regional hospitals and 25 Ambulance Victoria branches (AV). Post-training, clinicians involved in treating patients with suspected stroke or cardiac events were administered surveys measuring perceived organisational readiness (Organisational Readiness for Implementing Change), clinicians' intentions (Unified Theory of Acceptance and Use of Technology) and internal motivations (Self-Determination Theory) to use Pulsara™, and the perceived benefits and barriers of use. Quantitative data were descriptively summarised with multivariable associations between factors and intentions to use Pulsara™ examined with linear regression. Qualitative data responses were subjected to directed content analysis (two coders)., Results: Participants were paramedics (n = 82, median 44 years) or hospital-based clinicians (n = 90, median 37 years), with organisations perceived to be similarly ready. Regression results (F(11, 136) = 21.28, p = <0.001, Adj R
2 = 0.60) indicated Habit, Effort Expectancy, Perceived Organisational Readiness, Performance Expectancy and Organisation membership (AV) as predictors of intending to use Pulsara™. Themes relating to benefits (95% coder agreement) included improved communication, procedural efficiencies and faster patient care. Barriers (92% coder agreement) included network accessibility and remembering passwords. PulsaraTM was initiated 562 times., Conclusion: Implementing multiorganisational, digital health communication applications is feasible, and facilitated when organisations are change-ready for an easy-to-use, effective solution. Developing habitual use is key, supported through implementation strategies (e.g., hands-on training). Benefits should be emphasised (e.g., during education sessions), including streamlining communication and patient flow, and barriers addressed (e.g., identify champions and local technical support) at project commencement., (© 2023 The Authors. Journal of Evaluation in Clinical Practice published by John Wiley & Sons Ltd.)- Published
- 2024
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13. Overcoming the clinical challenges of traditional ayahuasca: a first-in-human trial exploring novel routes of administration of N,N-Dimethyltryptamine and harmine.
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Dornbierer DA, Marten L, Mueller J, Aicher HD, Mueller MJ, Boxler M, Kometer M, Kosanic D, von Rotz R, Puchkov M, Kraemer T, Landolt HP, Seifritz E, and Scheidegger M
- Abstract
Recently, the Amazonian plant medicine "ayahuasca"-containing the psychedelic compound N,N-dimethyltryptamine (DMT) and numerous β-carboline alkaloids, such as harmine-has been suggested to exhibit beneficial effects in patients with affective and other mental health disorders. Although ayahuasca ingestion is considered safe, its pharmacokinetics/pharmacodynamics and tolerability profile pose some challenges and may limit the clinical applicability in vulnerable patient populations. While overdosing and the admixture of intolerable plant constituents may explain some of the common adverse reactions, the peroral route of administration may represent another relevant source of gastro-intestinal intolerabilities and unpredictable pharmacokinetics across users. To overcome these challenges, the present work aimed at creating ayahuasca-analogue formulations with improved pharmacokinetics and tolerability profiles. To this end, we developed peroral formulas and compared them with parenteral formulas specifically designed to circumvent the gastro-intestinal tract. In more detail, peroral administration of a capsule (containing purified DMT and harmine) was tested against a combined administration of an oromucosal harmine tablet and an intranasal DMT spray at two dose levels in an open-label within-subject study in 10 healthy male subjects. Pharmacokinetic and pharmacodynamic profiles were assessed by means of continuous blood sampling, vital sign monitoring, and psychometric assessments. Common side effects induced by traditional herbal ayahuasca such as nausea, vomiting, and diarrhea were significantly attenuated by our DMT/harmine formulations. While all preparations were well tolerated, the combined buccal/intranasal administration of harmine and DMT yielded substantially improved pharmacokinetic profiles, indicated by significantly reduced variations in systemic exposure. In conclusion, the combined buccal/intranasal administration of harmine and DMT is an innovative approach that may pave the way towards a safe, rapid-acting, and patient-oriented administration of DMT/harmine for the treatment of affective disorders. Clinical Trial Registration: clinicaltrials.gov, identifier NCT04716335., Competing Interests: DD, MK, DK, and MS declare that they co-founded Reconnect Labs, an academic spin-off at the University of Zurich, focused on the development of psychedelic medicines for mental health. MM and RR are shareholders of Reconnect Labs. All other co-authors have no conflict of interest to declare related to this work., (Copyright © 2023 Dornbierer, Marten, Mueller, Aicher, Mueller, Boxler, Kometer, Kosanic, von Rotz, Puchkov, Kraemer, Landolt, Seifritz and Scheidegger.)
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- 2023
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14. Untargeted Metabolomics Profiling for Determination of the Time since Deposition of Biofluids in a Forensic Context: A Proof-of-Concept for Urine, Saliva, and Semen in Addition to Blood.
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Schneider TD, Kraemer T, and Steuer AE
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- Humans, Aged, Semen chemistry, Bodily Secretions, Forensic Medicine methods, Saliva chemistry, Body Fluids chemistry
- Abstract
In a criminal trial, the reconstruction of a crime is one of the fundamental steps of the prosecution process. Common questions, such as what happened, where and how it happened, and who made it happen, need to be solved. Biological evidence at crime scenes can be crucial in the determination of these fundamental questions. One of the more challenging riddles to solve is the when? A trace left at a crime scene can prove a person's presence at the crime scene. Knowledge about when it was deposited there, the time since deposition (TsD), would allow linking the person in space and time to the site. This could fortify allegations against a suspect or discharge accusations if proven to be outside of the temporal boundaries where a suspected crime had occurred. Determining the TsD has yet to become routine forensic casework, despite recent research efforts, especially for blood traces. However, next to blood, other biological traces are also commonly encountered in crime scenes. We here present a study to profile the metabolomes of artificially aged dried body fluid spots of blood, semen, saliva, and urine over 4 weeks by liquid chromatography high-resolution mass spectrometry and data-dependent acquisition. All four body fluids (BFs) exhibited diverse time-dependent changes, and a large number of molecular features (MF) were associated with TsD. Still, significant differences between the BFs were observed, limiting universal interpretability independent of the BF and facilitating a need to further study time-dependent changes of different BFs individually toward the goal of TsD estimation.
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- 2023
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15. Determination of the Time since Deposition of blood-traces in a forensic context: Application of untargeted LC-HR-MS/MS metabolomics profiling.
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Schneider TD, Kraemer T, and Steuer AE
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- Humans, Aged, Forensic Medicine methods, Chromatography, Liquid methods, Metabolome, Tandem Mass Spectrometry methods, Metabolomics methods
- Abstract
Being able to attest when a bloodstain was deposited at a crime scene can be invaluable to a prosecution process, and methods to provide that information have long been desired. Determining the Time since Deposition (TsD) of a trace would allow placing a subject both in space and time to the crime scene-or prove that a trace left by that person was unrelated to it because it was deposited before or after the time the crime had occurred. To this day, no method for TsD determination has made its way into routine forensic casework, mainly because of the numerous challenges that await when trying to understand and account for all the influencing and confounding factors that affect the aging process (such as, e.g., temperature, UV-light exposure, or humidity). Here, we present an untargeted metabolomics-based study using liquid chromatography high-resolution mass spectrometry (LC-HR-MS) and data-dependent acquisition to analyze blood samples aged under two distinctly different storage conditions over 48 weeks. Global differences in age- and storage-dependent changes in blood metabolomes were described, and TsD-classification strategies based on qualitative and quantitative assessment of molecular features (MFs) have been proposed. Based on the selected criteria to best predict the TsD, the dipeptide Phenylalanylalanine (PheAla) can be considered as a promising candidate for TsD prediction. In essence, changes in the blood metabolome dynamics showed a strong association with increasing TsD, but significant differences depending on storage conditioning were observed, facilitating the need to study further the influence of individual influencing factors on TsD determination., (© 2023 The Authors. Drug Testing and Analysis published by John Wiley & Sons Ltd.)
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- 2023
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16. Nocturnal sodium oxybate increases the anterior cingulate cortex magnetic resonance glutamate signal upon awakening.
- Author
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Dornbierer DA, Zölch N, Baur DM, Hock A, Stucky B, Quednow BB, Kraemer T, Seifritz E, Bosch OG, and Landolt HP
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- Humans, Glutamic Acid, Gyrus Cinguli diagnostic imaging, Magnetic Resonance Spectroscopy, Sodium Oxybate pharmacology, Sodium Oxybate therapeutic use, Narcolepsy drug therapy, Disorders of Excessive Somnolence
- Abstract
Clinical guidelines recommend sodium oxybate (SXB; the sodium salt of γ-hydroxybutyrate) for the treatment of disturbed sleep and excessive daytime sleepiness in narcolepsy, yet the underlying mode of action is elusive. In a randomised controlled trial in 20 healthy volunteers, we aimed at establishing neurochemical changes in the anterior cingulate cortex (ACC) following SXB-enhanced sleep. The ACC is a core neural hub regulating vigilance in humans. At 2:30 a.m., we administered in a double-blind cross-over manner an oral dose of 50 mg/kg SXB or placebo, to enhance electroencephalography-defined sleep intensity in the second half of nocturnal sleep (11:00 p.m. to 7:00 a.m.). Upon scheduled awakening, we assessed subjective sleepiness, tiredness and mood and measured two-dimensional, J-resolved, point-resolved magnetic resonance spectroscopy (PRESS) localisation at 3-Tesla field strength. Following brain scanning, we used validated tools to quantify psychomotor vigilance test (PVT) performance and executive functioning. We analysed the data with independent t tests, false discovery rate (FDR) corrected for multiple comparisons. The morning glutamate signal (at 8:30 a.m.) in the ACC was specifically increased after SXB-enhanced sleep in all participants in whom good-quality spectroscopy data were available (n = 16; p
FDR < 0.002). Further, global vigilance (10th-90th inter-percentile range on the PVT) was improved (pFDR < 0.04) and median PVT response time was shorter (pFDR < 0.04) compared to placebo. The data indicate that elevated glutamate in the ACC could provide a neurochemical mechanism underlying SXB's pro-vigilant efficacy in disorders of hypersomnolence., (© 2023 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.)- Published
- 2023
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17. Urinary concentrations of GHB and its novel amino acid and carnitine conjugates following controlled GHB administration to humans.
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Steuer AE, Bavato F, Schnider LK, Dornbierer DA, Bosch OG, Quednow BB, Seifritz E, Steuer C, and Kraemer T
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- Humans, Amino Acids, Carnitine, Chromatography, Liquid, Tandem Mass Spectrometry, Glycine, Substance Abuse Detection, Hydroxybutyrates, Sodium Oxybate
- Abstract
Gamma-hydroxybutyrate (GHB) remains a challenging clinical/forensic toxicology drug. Its rapid elimination to endogenous levels mainly causes this. Especially in drug-facilitated sexual assaults, sample collection often occurs later than the detection window for GHB. We aimed to investigate new GHB conjugates with amino acids (AA), fatty acids, and its organic acid metabolites for their suitability as ingestion/application markers in urine following controlled GHB administration to humans. We used LC-MS/MS for validated quantification of human urine samples collected within two randomized, double-blinded, placebo-controlled crossover studies (GHB 50 mg/kg, 79 participants) at approximately 4.5, 8, 11, and 28 h after intake. We found significant differences (placebo vs. GHB) for all but two analytes at 4.5 h. Eleven hours post GHB administration, GHB, GHB-AAs, 3,4-dihydroxybutyric acid, and glycolic acid still showed significantly higher concentrations; at 28 h only GHB-glycine. Three different discrimination strategies were evaluated: (a) GHB-glycine cut-off concentration (1 µg/mL), (b) metabolite ratios of GHB-glycine/GHB (2.5), and (c) elevation threshold between two urine samples (> 5). Sensitivities were 0.1, 0.3, or 0.5, respectively. Only GHB-glycine showed prolonged detection over GHB, mainly when compared to a second time- and subject-matched urine sample (strategy c)., (© 2023. The Author(s).)
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- 2023
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18. TiO 2 nanoparticles abrogate the protective effect of the Crohn's disease-associated variation within the PTPN22 gene locus.
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Schwarzfischer M, Niechcial A, Handler K, Morsy Y, Wawrzyniak M, Laimbacher AS, Atrott K, Manzini R, Baebler K, Hering L, Katkeviciutė E, Häfliger J, Lang S, Keller ME, Woodtli J, Eisenbeiss L, Kraemer T, Schraner EM, Wiesendanger M, Zeissig S, Rogler G, Moor AE, Scharl M, and Spalinger MR
- Subjects
- Mice, Animals, CD8-Positive T-Lymphocytes metabolism, Inflammation complications, Dextran Sulfate, Disease Models, Animal, Mice, Inbred C57BL, Protein Tyrosine Phosphatase, Non-Receptor Type 22 genetics, Crohn Disease genetics, Crohn Disease complications, Colitis chemically induced, Colitis genetics, Colitis prevention & control, Inflammatory Bowel Diseases, Nanoparticles
- Abstract
Objective: Inflammatory bowel disease (IBD) is a multifactorial condition driven by genetic and environmental risk factors. A genetic variation in the protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene has been associated with autoimmune disorders while protecting from the IBD subtype Crohn's disease. Mice expressing the murine orthologous PTPN22-R619W variant are protected from intestinal inflammation in the model of acute dextran sodium sulfate (DSS)-induced colitis. We previously identified food-grade titanium dioxide (TiO
2 , E171) as a neglected IBD risk factor. Here, we investigate the interplay of the PTPN22 variant and TiO2 -mediated effects during IBD pathogenesis., Design: Acute DSS colitis was induced in wild-type and PTPN22 variant mice (PTPN22-R619W) and animals were treated with TiO2 nanoparticles during colitis induction. Disease-triggering mechanisms were investigated using bulk and single-cell RNA sequencing., Results: In mice, administration of TiO2 nanoparticles abrogated the protective effect of the variant, rendering PTPN22-R619W mice susceptible to DSS colitis. In early disease, cytotoxic CD8+ T-cells were found to be reduced in the lamina propria of PTPN22-R619W mice, an effect reversed by TiO2 administration. Normalisation of T-cell populations correlated with increased Ifng expression and, at a later stage of disease, the promoted prevalence of proinflammatory macrophages that triggered severe intestinal inflammation., Conclusion: Our findings indicate that the consumption of TiO2 nanoparticles might have adverse effects on the gastrointestinal health of individuals carrying the PTPN22 variant. This demonstrates that environmental factors interact with genetic risk variants and can reverse a protective mechanism into a disease-promoting effect., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)- Published
- 2023
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19. New gamma-hydroxybutyric acid (GHB) biomarkers: Development and validation of a liquid chromatography-tandem mass spectrometry method for the determination of GHB amino acid, carnitine, and fatty acid conjugates in urine.
- Author
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Steuer AE, Sutter L, Steuer C, and Kraemer T
- Subjects
- Humans, Chromatography, Liquid methods, Amino Acids, Tandem Mass Spectrometry methods, Fatty Acids, Hydroxybutyrates analysis, Carnitine, Biomarkers metabolism, Glycine, Taurine, Sodium Oxybate urine
- Abstract
Gamma-hydroxybutyric acid (GHB) represents an important drug in clinical and forensic toxicology, particularly in the context of drug-facilitated crimes. Analytically, GHB remains a major challenge given its endogenous occurrence and short detection window. Previous studies identified a number of potential interesting novel conjugates of GHB with carnitine, amino acids (AA, glutamate, glycine, and taurine), or fatty acids. As a basis for comprehensive studies on the suitability of these novel biomarkers, we developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method in human urine. Additionally, already known markers 2,4-dihydroxy butyric acid (2,4-DHB), 3,4-DHB, glycolic acid, succinic acid, succinylcarnitine, and GHB glucuronide were included. The method was fully validated according to (inter)national guidelines. Synthetic urine proved suitable as a surrogate matrix for calibration. Matrix effects were observed for all analytes with suppression effects of about 50% at QC LOW, and approximately 20% to 40% at QC HIGH, but with consistent standard deviation of <25% at QC LOW and <15% at QC HIGH, respectively. All analytes showed acceptable intra- and inter-day imprecision of below 20%, except for inter-day variation of GHB taurine and FA conjugates at the lowest QC. Preliminary applicability studies proved the usefulness of the method and pointed towards GHB glycine, followed by other AA conjugates as the most promising candidates to improve GHB detection. FA conjugates were not detected in urine samples yet. The method can be used now for comprehensive sample analysis on (controlled) GHB administration to prove the usefulness of the novel GHB biomarkers., (© 2022 John Wiley & Sons Ltd.)
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- 2023
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20. Metabolomics-based Sleepiness Markers for Risk Prevention and Traffic Safety (ME-SMART): a monocentric, controlled, randomized, crossover trial.
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Scholz M, Lakaemper S, Keller K, Dobay A, Steuer AE, Landolt HP, and Kraemer T
- Subjects
- Humans, Cross-Over Studies, Sleep physiology, Wakefulness physiology, Sleep Deprivation complications, Sleepiness
- Abstract
Background: Too little sleep and the consequences thereof are a heavy burden in modern societies. In contrast to alcohol or illicit drug use, there are no quick roadside or workplace tests for objective biomarkers for sleepiness. We hypothesize that changes in physiological functions (such as sleep-wake regulation) are reflected in changes of endogenous metabolism and should therefore be detectable as a change in metabolic profiles. This study will allow for creating a reliable and objective panel of candidate biomarkers being indicative for sleepiness and its behavioral outcomes., Methods: This is a monocentric, controlled, randomized, crossover, clinical study to detect potential biomarkers. Each of the anticipated 24 participants will be allocated in randomized order to each of the three study arms (control, sleep restriction, and sleep deprivation). These only differ in the amount of hours slept per night. In the control condition, participants will adhere to a 16/8 h wake/sleep regime. In both sleep restriction and sleep deprivation conditions, participants will accumulate a total sleep deficit of 8 h, achieved by different wake/sleep regimes that simulate real-life scenarios. The primary outcome is changes in the metabolic profile (i.e., metabolome) in oral fluid. Secondary outcome measures will include driving performance, psychomotor vigilance test, d2 Test of Attention, visual attention test, subjective (situational) sleepiness, electroencephalographic changes, behavioral markers of sleepiness, changes in metabolite concentrations in exhaled breath and finger sweat, and correlation of metabolic changes among biological matrices., Discussion: This is the first trial of its kind that investigates complete metabolic profiles combined with performance monitoring in humans over a multi-day period involving different sleep-wake schedules. Hereby, we aim to establish a candidate biomarker panel being indicative for sleepiness and its behavioral outcomes. To date, there are no robust and easily accessible biomarkers for the detection of sleepiness, even though the vast damage on society is well known. Thus, our findings will be of high value for many related disciplines., Trial Registration: ClinicalTrials.gov Identifier NCT05585515, released on 18.10.2022; Swiss National Clinical Trial Portal SNCTP000005089, registered on 12 August 2022., (© 2023. The Author(s).)
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- 2023
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21. Flawless victory! Investigating search and experience qualities as antecedent predictors of video game success.
- Author
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Heidenreich S, Handrich F, and Kraemer T
- Abstract
In recent years, video games have been on the rise as entertainment goods, leading to a growing interest by practitioners, researchers, and, of course, consumers alike. While a few unusually successful video games produce overall high revenues, most released games struggle to break even. Hence, there is an urgent need to better understand what distinguishes financially successful games from nonsuccessful video games. Accordingly, several researchers have called for investigations into the drivers of the financial success of video games. However, empirical studies within this respect are still lacking. Based on longitudinal data of 351 video games, the current study strives to fill this research gap by investigating the relative importance of potential success factors for the short-term and long-term financial success of video games. The results of multiple regression analyses confirm that search qualities such as brand popularity, reviews, and awards as well as experience qualities such as graphics, sound, and game duration significantly drive financial success in terms of the total number of sold video games in Europe. Consequently, managers in the video game industry can boost their chances for the production of a successful video game by focusing on these factors., (© The Author(s) 2023.)
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- 2023
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22. Single sample preparation for the simultaneous extraction of drugs, pharmaceuticals, cannabinoids and endogenous steroids in hair.
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Scholz C, Baumgartner MR, Kraemer T, and Binz TM
- Subjects
- Chromatography, Liquid methods, Tandem Mass Spectrometry methods, Hair chemistry, Steroids, Pharmaceutical Preparations, Cannabinoids analysis
- Abstract
Recently, we published a multi-analyte method for the simultaneous analysis of 116 drugs and pharmaceuticals including different substance groups like opioids, stimulants, benzodiazepines, z-drugs, antidepressants and neuroleptics based on a single sample workup followed by a single analytical measurement with LC-MS/MS. However, in some cases, additional analysis of further substance groups, such as cannabinoids and endogenous steroids, is required, which are analyzed in our laboratory using separate sample preparation and separate analytical methods. The goal of this study was to use the knowledge from the different sample preparations and combine them into a single sample preparation and extraction workflow for the simultaneous extraction of drugs, pharmaceuticals, cannabinoids, and endogenous steroids to be analyzed with the appropriate analytical methods. A partial validation of selected parameters such as selectivity, linearity, limit of quantification (LOQ), accuracy, precision and robustness for the different analytical methods was carried out and revalidated. In addition, comparative measurements of quality controls and authentic pools were performed and statistically evaluated using the unpaired t -test or the non-parametric Mann-Whitney test. The results using the newly established sample preparation and extraction were in good agreement with the original data. In conclusion, the newly established sample preparation is suitable for the combined extraction of drugs, pharmaceuticals, cannabinoids and endogenous steroids, and gives reliable results for quantification of various substances.
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- 2022
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23. Inhaled mosliciguat (BAY 1237592): targeting pulmonary vasculature via activating apo-sGC.
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Becker-Pelster EM, Hahn MG, Delbeck M, Dietz L, Hüser J, Kopf J, Kraemer T, Marquardt T, Mondritzki T, Nagelschmitz J, Nikkho SM, Pires PV, Tinel H, Weimann G, Wunder F, Sandner P, Schuhmacher J, Stasch JP, and Truebel HKF
- Subjects
- Acetylcholine, Animals, Guanylate Cyclase metabolism, Guanylate Cyclase therapeutic use, Nitric Oxide metabolism, Rats, Soluble Guanylyl Cyclase metabolism, Soluble Guanylyl Cyclase therapeutic use, Swine, Swine, Miniature metabolism, Thromboxanes therapeutic use, Vasodilator Agents, Hypertension, Pulmonary
- Abstract
Background: Oxidative stress associated with severe cardiopulmonary diseases leads to impairment in the nitric oxide/soluble guanylate cyclase signaling pathway, shifting native soluble guanylate cyclase toward heme-free apo-soluble guanylate cyclase. Here we describe a new inhaled soluble guanylate cyclase activator to target apo-soluble guanylate cyclase and outline its therapeutic potential., Methods: We aimed to generate a novel soluble guanylate cyclase activator, specifically designed for local inhaled application in the lung. We report the discovery and in vitro and in vivo characterization of the soluble guanylate cyclase activator mosliciguat (BAY 1237592)., Results: Mosliciguat specifically activates apo-soluble guanylate cyclase leading to improved cardiopulmonary circulation. Lung-selective effects, e.g., reduced pulmonary artery pressure without reduced systemic artery pressure, were seen after inhaled but not after intravenous administration in a thromboxane-induced pulmonary hypertension minipig model. These effects were observed over a broad dose range with a long duration of action and were further enhanced under experimental oxidative stress conditions. In a unilateral broncho-occlusion minipig model, inhaled mosliciguat decreased pulmonary arterial pressure without ventilation/perfusion mismatch. With respect to airway resistance, mosliciguat showed additional beneficial bronchodilatory effects in an acetylcholine-induced rat model., Conclusion: Inhaled mosliciguat may overcome treatment limitations in patients with pulmonary hypertension by improving pulmonary circulation and airway resistance without systemic exposure or ventilation/perfusion mismatch. Mosliciguat has the potential to become a new therapeutic paradigm, exhibiting a unique mode of action and route of application, and is currently under clinical development in phase Ib for pulmonary hypertension., (© 2022. The Author(s).)
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- 2022
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24. Determination of the Time since Deposition of Blood Traces Utilizing a Liquid Chromatography-Mass Spectrometry-Based Proteomics Approach.
- Author
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Schneider TD, Roschitzki B, Grossmann J, Kraemer T, and Steuer AE
- Subjects
- Chromatography, Liquid, Peptides, Tandem Mass Spectrometry, Blood Stains, Proteomics
- Abstract
Knowledge about when a bloodstain was deposited at a crime scene can be of critical value in forensic investigation. A donor of a genetically identified bloodstain could be linked to a suspected time frame and the crime scene itself. Determination of the time since deposition (TsD) has been extensively studied before but has yet to reach maturity. We therefore conducted a proof-of-principle study to study time- and storage-dependent changes of the proteomes of dried blood stains. A bottom-up proteomics approach was employed, and high-resolution liquid-chromatography-mass-spectrometry (HR-LC-MS) and data-independent acquisition (DIA) were used to analyze samples aged over a 2 month period and two different storage conditions. In multivariate analysis, samples showed distinct clustering according to their TsD in both principal component analysis (PCA) and in partial least square discriminant analysis (PLS DA). The storage condition alters sample aging and yields different separation-driving peptides in hierarchical clustering and in TsD marker peptide selection. Certain peptides and amino acid modifications were identified and further assessed for their applicability in assessing passed TsD. A prediction model based on data resampling (Jackknife) was applied, and prediction values for selected peptide ratios were created. Depending on storage conditions and actual sample age, mean prediction performances ranges in between 70 and 130% for the majority of peptides and time points. This places this study as a first in investigating LC-MS based bottom-up proteomics approaches for TsD determination.
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- 2022
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25. Endocannabinoid and steroid analysis in infant and adult nails by LC-MS/MS.
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Restin T, Byland N, Voegel CD, La Marca-Ghaemmaghami P, Baumgartner MR, Bassler D, Kraemer T, and Binz TM
- Subjects
- Adult, Child, Humans, Infant, Infant, Newborn, Chromatography, Liquid methods, Hydrocortisone analysis, Nails chemistry, Pilot Projects, Progesterone analysis, Retrospective Studies, Tandem Mass Spectrometry methods, Endocannabinoids analysis, Steroids analysis
- Abstract
A common method to quantify chronic stress is the analysis of stress markers in keratinized matrices such as hair or nail. In this study, we aimed to validate a sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the combined quantification of steroid hormones and endocannabinoids (eCBs) in the keratinized matrix nail. Furthermore, we aimed to investigate the suitability of the nail matrix for the detection of these stress markers in a pilot study. An LC-MS/MS method was used for the simultaneous identification and quantification of four eCBs (2-arachidonoylglycerol (2-AG), anandamide (AEA), oleoylethanolamide (OEA), palmitoylethanolamide (PEA)) and five steroid hormones (cortisol, cortisone, androstenedione, progesterone, testosterone) in human nails using a surrogate analyte method for each analyte. The method was validated in terms of selectivity, response factor, linearity, limit of quantification (LOQ), precision, accuracy, matrix effect, recovery, robustness, and autosampler stability. Nail samples were extracted for 1 h with methanol following a clean-up with a fully automated supported liquid extraction (SLE). The influence of nail weight on the quantification was investigated by using 0.5-20 mg of nail sample. As a proof of concept, nail samples (N = 57) were analyzed from a cohort representing newborns (1 month old), children (between 1 and 10 years), and adults (up to 43 years). It could be shown that the established workflow using a 1 hour extraction and clean-up by SLE was very robust and resulted in a short sample preparation time. The LC-MS/MS method was successfully validated. Matrix effects with ion enhancement occurred mainly for 2-AG. Sample weights below 5 mg showed variations in quantification for some analytes. Certain analytes such as PEA and progesterone could be accurately quantified at a sample weight lower than 5 mg. This is the first study where steroids and eCBs could be simultaneously detected and quantified in infant and adult nails. These results show that nails may serve as an alternative keratinized matrix (compared to hair) for the retrospective monitoring of cumulative eCB and steroid hormone levels. The combined assessment of eCBs and steroids from nails could provide a new approach to gain new insights into stress exposure in newborns and adults., (© 2022. The Author(s).)
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- 2022
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26. Real-world, feasibility study to investigate the use of a multidisciplinary app (Pulsara) to improve prehospital communication and timelines for acute stroke/STEMI care.
- Author
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Bladin CF, Bagot KL, Vu M, Kim J, Bernard S, Smith K, Hocking G, Coupland T, Pearce D, Badcock D, Budge M, Nadurata V, Pearce W, Hall H, Kelly B, Spencer A, Chapman P, Oqueli E, Sahathevan R, Kraemer T, Hair C, Stub D, and Cadilhac DA
- Subjects
- Ambulances, Arrhythmias, Cardiac, Communication, Electrocardiography, Feasibility Studies, Female, Humans, Male, Time Factors, Treatment Outcome, Victoria, Emergency Medical Services, Mobile Applications, Myocardial Infarction therapy, ST Elevation Myocardial Infarction therapy, Stroke therapy
- Abstract
Objectives: To determine if a digital communication app improves care timelines for patients with suspected acute stroke/ST-elevation myocardial infarction (STEMI)., Design: Real-world feasibility study, quasi-experimental design., Setting: Prehospital (25 Ambulance Victoria branches) and within-hospital (2 hospitals) in regional Victoria, Australia., Participants: Paramedics or emergency department (ED) clinicians identified patients with suspected acute stroke (onset <4.5 hours; n=604) or STEMI (n=247)., Intervention: The Pulsara communication app provides secure, two-way, real-time communication. Assessment and treatment times were recorded for 12 months (May 2017-April 2018), with timelines compared between 'Pulsara initiated' (Pulsara) and 'not initiated' (no Pulsara)., Primary Outcome Measure: Door-to-treatment (needle for stroke, balloon for STEMI) Secondary outcome measures: ambulance and hospital processes., Results: Stroke (no Pulsara n=215, Pulsara n=389) and STEMI (no Pulsara n=76, Pulsara n=171) groups were of similar age and sex (stroke: 76 vs 75 years; both groups 50% male; STEMI: 66 vs 63 years; 68% and 72% male). When Pulsara was used, patients were off ambulance stretcher faster for stroke (11(7, 17) vs 19(11, 29); p=0.0001) and STEMI (14(7, 23) vs 19(10, 32); p=0.0014). ED door-to-first medical review was faster (6(2, 14) vs 23(8, 67); p=0.0001) for stroke but only by 1 min for STEMI (3 (0, 7) vs 4 (0, 14); p=0.25). Door-to-CT times were 44 min faster (27(18, 44) vs 71(43, 147); p=0.0001) for stroke, and percutaneous intervention door-to-balloon times improved by 17 min, but non-significant (56 (34, 88) vs 73 (49, 110); p=0.41) for STEMI. There were improvements in the proportions of patients treated within 60 min for stroke (12%-26%, p=0.15) and 90 min for STEMI (50%-78%, p=0.20)., Conclusions: In this Australian-first study, uptake of the digital communication app was strong, patient-centred care timelines improved, although door-to-treatment times remained similar., Competing Interests: Competing interests: None of the authors have a financial interest in the Pulsara app or Pulsara Communicare Technology. KB and DAC received a travel grant paid to their institution from Pulsara Communicare Technology. This grant was a contribution to defray the costs of attending an international conference to present the final results. The peer-reviewed abstract submission was accepted prior to receiving the travel grant. The company had no input to the content of the abstracts or the presentations (nor this manuscript)., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)
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- 2022
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27. Towards a New Qualitative Screening Assay for Synthetic Cannabinoids Using Metabolomics and Machine Learning.
- Author
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Streun GL, Steuer AE, Poetzsch SN, Ebert LC, Dobay A, and Kraemer T
- Subjects
- Chromatography, Liquid methods, Forensic Toxicology methods, Humans, Machine Learning, Cannabinoids analysis, Metabolomics
- Abstract
Background: Synthetic cannabinoids (SCs) are steadily emerging on the drug market. To remain competitive in clinical or forensic toxicology, new screening strategies including high-resolution mass spectrometry (HRMS) are required. Machine learning algorithms can detect and learn chemical signatures in complex datasets and use them as a proxy to predict new samples. We propose a new screening tool based on a SC-specific change of the metabolome and a machine learning algorithm., Methods: Authentic human urine samples (n = 474), positive or negative for SCs, were used. These samples were measured with an untargeted metabolomics liquid chromatography (LC)-quadrupole time-of-flight-HRMS method. Progenesis QI software was used to preprocess the raw data. Following feature engineering, a random forest (RF) model was optimized in R using a 10-fold cross-validation method and a training set (n = 369). The performance of the model was assessed with a test (n = 50) and a verification (n = 55) set., Results: During RF optimization, 49 features, 200 trees, and 7 variables at each branching node were determined as most predictive. The optimized model accuracy, clinical sensitivity, clinical specificity, positive predictive value, and negative predictive value were 88.1%, 83.0%, 92.7%, 91.3%, and 85.6%, respectively. The test set was predicted with an accuracy of 88.0%, and the verification set provided evidence that the model was able to detect cannabinoid-specific changes in the metabolome., Conclusions: An RF approach combined with metabolomics enables a novel screening strategy for responding effectively to the challenge of new SCs. Biomarkers identified by this approach may also be integrated in routine screening methods., (© American Association for Clinical Chemistry 2022. All rights reserved. For permissions, please email: journals.permissions@oup.com.)
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- 2022
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28. LC-MS-MS Analysis of Δ9-THC, CBN and CBD in Hair: Investigation of Artifacts.
- Author
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Scholz C, Madry MM, Kraemer T, and Baumgartner MR
- Subjects
- Artifacts, Chromatography, Liquid, Dronabinol analysis, Hair chemistry, Tandem Mass Spectrometry methods, Cannabidiol analysis, Cannabinol analysis
- Abstract
In forensic toxicology, high-performance liquid chromatography tandem mass spectrometry (LC-MS-MS) is increasingly used for the fast and sensitive measurement of a wide range of drugs. For our routine casework, a LC atmospheric pressure chemical ionization MS-MS method for the quantification of Δ9-tetrahydrocannabinol (Δ9-THC), cannabinol (CBN) and cannabidiol (CBD) in hair was established and fully validated. Separation was achieved using a Kinetex® C18 column (100 mm × 2.1 mm, 100 Å, 1.7 μm, Phenomenex) at a flow rate of 0.5 mL/min. Measurements were performed on a QTRAP 5500 mass spectrometer (Sciex, Darmstadt, Germany). Unexpected signals were observed in authentic THC-positive hair samples. First, a signal with a slightly shifted retention time of THC whose origin could be assigned to the isomer Δ8-THC was detected. Second, additional peaks exhibiting the same fragments as CBN and Δ9-THC but eluting at different retention times were detected. Spiking experiments and enhanced product ion scans pointed to the origin of these additional signals as result of in-source decarboxylation of Δ9-tetrahydrocannabinolic acid A (Δ9-THCA-A) into Δ9-THC and further partial oxidation of Δ9-THC into CBN, respectively. Positive findings of Δ9-THCA-A in hair have been shown to derive from external contamination; therefore, the herein described artifacts may be used as indirect markers for external contamination., (© The Author(s) 2021. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2022
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29. Diabetes in ischaemic stroke in a regional Australian hospital: uncharted territory.
- Author
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Hu CC, Low A, O'Connor E, Siriratnam P, Hair C, Kraemer T, and Sahathevan R
- Subjects
- Australia epidemiology, Hospitals, Humans, Retrospective Studies, Risk Factors, Brain Ischemia epidemiology, Diabetes Mellitus epidemiology, Ischemic Attack, Transient epidemiology, Ischemic Stroke, Stroke epidemiology
- Abstract
Background: Stroke and diabetes mellitus (DM) are significant interrelated healthcare issues but there is a dearth of data on the prevalence of DM among Australia's regional stroke population., Aims: We aimed to determine the prevalence of DM in stroke patients at a large regional centre, including subanalyses on stroke subtypes, glycaemic control and renal function in ischaemic stroke (IS)., Methods: We conducted a retrospective analysis of all patients (n = 323) with IS or transient ischaemic attack (TIA) admitted to Ballarat Base Hospital from January 2015 to December 2016. Demographic data, cardiovascular risk factors, aetiology/territory of IS, pre-morbid DM status, indicators of glycaemic control and renal impairment were recorded., Results: DM was present in 28.5% of IS and TIA patients, including 4% being newly diagnosed. Among diabetic IS patients, 45.3% had poor glycaemic control (HbA1c ≥7.0%) while 16% had moderate to severe renal impairment (estimated glomerular filtration rate of <30). The majority of IS were partial anterior circulation stroke (53.4%) and cardioembolism was the commonest mechanism (43.5%). We found no significant association between DM and a specific stroke location or mechanism., Conclusions: Almost one-third of IS/TIA patients had DM, with a significant proportion showing poor glycaemic control. The DM prevalence in our cohort was comparable with reported rates from other developed countries. Although we found no association between DM and a particular stroke type or mechanism, it is likely a reflection of our cohort size. Our study demonstrated that DM, as a significant risk factor in IS, warrants early detection and better management strategies., (© 2020 Royal Australasian College of Physicians.)
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- 2022
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30. Alterations of Stress-Related Glucocorticoids and Endocannabinoids in Hair of Chronic Cocaine Users.
- Author
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Voegel CD, Kroll SL, Schmid MW, Kexel AK, Baumgartner MR, Kraemer T, Binz TM, and Quednow BB
- Subjects
- Animals, Endocannabinoids, Glucocorticoids, Hair, Humans, Hypothalamo-Hypophyseal System, Pituitary-Adrenal System, Cocaine, Cortisone
- Abstract
Background: Previous research in animals and humans has demonstrated a potential role of stress regulatory systems, such as the hypothalamic-pituitary-adrenal (HPA) axis and the endocannabinoid (eCB) system, in the development of substance use disorders. We thus investigated alterations of HPA and eCB markers in individuals with chronic cocaine use disorder by using an advanced hair analysis technique., Methods: We compared hair concentrations of glucocorticoids (cortisone, cortisol) and the eCBs 2-arachidonylglycerol, anandamide (AEA), oleoylethanolamide (OEA), and palmitoylethanolamide (PEA) between 48 recreational cocaine users (RCU), 25 dependent cocaine users (DCU), and 67 stimulant-naïve controls. Self-reported substance use and hair concentrations of substances were also assessed., Results: Significantly higher concentrations of hair cortisone were found in RCU and DCU compared with controls. Hair concentrations of OEA and PEA were significantly lower in DCU compared with RCU and controls. Additionally, within cocaine users, elevated cocaine hair concentration was a significant predictor for increased glucocorticoid and decreased OEA hair levels. Moreover, higher 3,4-methylenedioxymethamphetamine hair concentration was correlated with elevated cortisone and AEA, OEA, and PEA levels in hair within cocaine users, whereas more self-reported cannabis use was associated with lower eCBs levels in hair across the total sample., Conclusion: Our findings support the hypothesis that the HPA axis and eCB system might be important regulators for substance use disorders. The mechanistic understanding of changes in glucocorticoid and eCB levels in future research might be a promising pharmacological target to reduce stress-induced craving and relapse specifically in cocaine use disorder., (© The Author(s) 2021. Published by Oxford University Press on behalf of CINP.)
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- 2022
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