BACKGROUND: This study aims to evaluate the feasibility of generating pseudo-normal single photon emission computed tomography (SPECT) data from potentially abnormal images. These pseudo-normal images are primarily intended for use in an on-the-fly data harmonization technique. MATERIAL AND METHODS: The methodology was tested on brain SPECT with [123I]Ioflupane. The proposed model for generating a pseudo-normal image was based on a variational autoencoder (VAE) designed to process 2D sinograms of the brain [123I]-FP-CIT SPECT, potentially exhibiting abnormal uptake. The model aimed to predict SPECT sinograms with corresponding normal uptake. Training, validation, and testing datasets were created by SPECT simulator from 45 brain masks segmented from real patient's magnetic resonance (MR) scans, using various uptake levels. The training and validation datasets each comprised 612 and 360 samples, respectively, drawn from 36 brain masks. The testing dataset contained 153 samples based on 9 brain masks. VAE performance was evaluated through brain dimensions, Dice similarity coefficient (DSC) and specific binding ratio. RESULTS: Mean DSC was 80% for left basal ganglia and 84% for right basal ganglia. The proposed VAE demonstrated excellent consistency in predicting basal ganglia shape, with a coefficient of variation of DSC being less than 1.1%. CONCLUSIONS: The study demonstrates that VAE can effectively estimate an individualized pseudo-normal distribution of the radiotracer [123I]-FP-CIT SPECT from abnormal SPECT images. The main limitations of this preliminary research are the limited availability of real brain MR data, used as input for the SPECT data simulator, and the simplified simulation setup employed to create the synthetic dataset.
- MeSH
- Tomography, Emission-Computed, Single-Photon * MeSH
- Humans MeSH
- Brain * diagnostic imaging MeSH
- Image Processing, Computer-Assisted * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Many small molecules require derivatization to increase their volatility and to be amenable to gas chromatographic (GC) separation. Derivatization is usually time-consuming, and typical batch-wise procedures increase sample variability. Sequential automation of derivatization via robotic liquid handling enables the overlapping of sample preparation and analysis, maximizing time efficiency and minimizing variability. Herein, a protocol for the fully automated, two-stage derivatization of human blood-based samples in line with GC-[Orbitrap] mass spectrometry (MS)-based metabolomics is described. The protocol delivers a sample-to-sample runtime of 31 min, being suitable for better throughput routine metabolomic analysis. Key features • Direct and rapid methoximation on vial followed by silylation of metabolites in various blood matrices. • Measure ~40 samples per 24 h, identifying > 70 metabolites. • Quantitative reproducibility of routinely measured metabolites with coefficients of variation (CVs) < 30%. • Requires a Thermo ScientificTM TriPlusTM RSH (or comparable) autosampler equipped with incubator/agitator, cooled drawer, and automatic tool change (ATC) station equipped with liquid handling tools. Graphical overview Workflow for profiling metabolites in human blood using automated derivatization.
- Publication type
- Journal Article MeSH
Objectives: This study evaluates the test-retest reliability and inter-rater reliability of the MyotonPRO for measuring Achilles tendon stiffness at two standardized sites over various time frames and settings. Methods: Eight healthy participants underwent assessments by three raters over six visits. Tendon stiffness was measured at proximal (mid-portion) and distal (insertional) regions of the Achilles tendon at various time frames (10-15 s, 10-15 min, 24 h, and 14 days apart). Measurements included participant repositioning and two activity stimuli (daily living and sport). Reliability was calculated using the intraclass correlation coefficient (ICC), its 95% confidence interval, coefficient of variation, standard error of measurement, and minimal detectable change. Results: Short-term reliability (10-15 min) was excellent, with an ICC of 0.956 (0.929-0.974). Between days reliability (24 h) was good, with an ICC of 0.889 (0.802-0.938). Between weeks reliability (2 weeks) was good with an ICC of 0.886 (0.811-0.931). Short-term reliability with the simulation of activity of daily living was good, with an ICC of 0.917 (0.875-0.945). Short-term reliability with the simulation of sport was good with an ICC of 0.933 (0.891-0.96). Between days reliability with the simulation of sport was good, with an ICC of 0.920 (0.859-0.955). Conclusions: When used in a standardized position, the MyotonPRO demonstrates reliable repeated measurements of Achilles tendon stiffness. This protocol provides a foundation for clinical research and rehabilitation by clarifying expected reliability across minutes, days, and weeks, thus aiding clinicians and researchers in monitoring tendon adaptations and making evidence-based decisions.
- Publication type
- Journal Article MeSH
OBJECTIVES: To evaluate the base excess response during acute in vivo carbon dioxide changes. DESIGN: Secondary analysis of individual participant data from experimental studies. SETTING: Three experimental studies investigating the effect of acute in vivo respiratory derangements on acid-base variables. SUBJECTS: Eighty-nine (canine and human) carbon dioxide exposures. INTERVENTIONS: Arterial carbon dioxide titration through environmental chambers or mechanical ventilation. MEASUREMENTS AND MAIN RESULTS: For each subject, base excess was calculated using bicarbonate and pH using a fixed buffer power of 16.2. Analyses were performed using linear regression with arterial dioxide (predictor), base excess (outcome), and studies (interaction term). All studies show different baselines and slopes for base excess across carbon dioxide titrations methods. Individual subjects show substantial, and potentially clinically relevant, variations in base excess response across the hypercapnic range. Using a mathematical simulation of 10,000 buffer power coefficients we determined that a coefficient of 12.1 (95% CI, 9.1-15.1) instead of 16.2 facilitates a more conceptually appropriate in vivo base excess equation for general clinical application. CONCLUSIONS: In vivo changes in carbon dioxide leads to changes in base excess that may be clinically relevant for individual patients. A buffer power coefficient of 16.2 may not be appropriate in vivo and needs external validation in a range of clinical settings.
- MeSH
- Acid-Base Equilibrium * physiology MeSH
- Adult MeSH
- Hypercapnia physiopathology metabolism MeSH
- Hydrogen-Ion Concentration MeSH
- Humans MeSH
- Carbon Dioxide * metabolism MeSH
- Acid-Base Imbalance physiopathology metabolism MeSH
- Dogs MeSH
- Respiration, Artificial MeSH
- Animals MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Male MeSH
- Dogs MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
BACKGROUND/PURPOSE: High doses to healthy cardiac substructures (CS) in stereotactic arrhythmia radioablation (STAR) raise concerns regarding potential treatment-induced cardio-toxicity. However, CS contours are not routinely created, hindering the understanding of the CS dose-effect relationships. To address this issue, the alignment of CS contouring was initiated within the STOPSTORM consortium. In this study, we developed and evaluated auto-contouring models trained to delineate CS and major vessels in ventricular tachycardia (VT) patients. METHODS: Eight centres provided standard treatment planning computed tomography (CT) and/or contrast-enhanced CT datasets of 55 VT patients, each including 16 CS. Auto-contouring models were trained to contour either large structures or small structures. Dice Similarity Coefficient (DSC), 95 % Hausdorff distance (HD95) and volume ratio (VR) were used to evaluate model performance versus inter-observer variation (IOV) on seven VT patient test cases. Significant differences were tested using the Mann-Whitney U test. RESULTS: The performance on the four chambers and the major vessels (median DSC: 0.88; HD95: 5.8-19.4 mm; VR: 1.09) was similar to the IOV (median DSC: 0.89; HD95: 4.8-14.0 mm; VR: 1.20). For the valves, model performance (median DSC: 0.37; HD95: 11.6 mm; VR: 1.63) was similar to the IOV (median DSC: 0.41; HD95: 12.4 mm; VR: 3.42), but slightly worse for the coronary arteries (median DSC: 0.33 vs 0.42; HD95: 24.4 mm vs 16.9 mm; VR: 1.93 vs 3.30). The IOV for these small structures remains large despite using contouring guidelines. CONCLUSION: CS auto-contouring models trained on VT patient data perform similarly to IOV. This allows for time-efficient evaluation of CS as possible organs-at-risk.
- MeSH
- Tachycardia, Ventricular * MeSH
- Organs at Risk radiation effects MeSH
- Middle Aged MeSH
- Humans MeSH
- Radiotherapy Planning, Computer-Assisted methods MeSH
- Tomography, X-Ray Computed * MeSH
- Radiosurgery * methods MeSH
- Aged MeSH
- Heart radiation effects MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Multicenter Study MeSH
Ocrelizumab is a second generation recombinant humanized IgG1 monoclonal antibody used for the treatment of multiple sclerosis that selectively target B cells expressing the CD20 antigen. This study aimed to develop and validate a UPLC-MS/MS method for quantification of ocrelizumab in human serum, which can be used in clinical applications for therapeutic drug monitoring. The analysis of ocrelizumab was performed using a bottom-up approach on a liquid chromatography coupled to tandem mass spectrometry detection. The method involved immunoglobulin precipitation with cold methanol followed by peptide digestion with trypsin. The resulting specific peptides were separated on an Acquity UPLC BEH C18 column at 55 °C using gradient elution. The method was validated according to European Medicines Agency (EMEA) guidelines and demonstrated intra- and inter-assay precision with coefficients of variation ranging from 1.6 % to 6.1 % and accuracies between 90.2 % and 107.2 %. Stability testing, including autosampler, long-term and freeze-thaw stability, showed no more than 15 % variation. The method was successfully applied to 169 patient samples, revealing ocrelizumab concentrations ranging from 0.5 to 21.8 mg/L in patients on 6-month dosing regimen and 20.5-65.0 mg/L in 16 patients receiving an initial two-week dose of 300 mg. The newly developed UPLC-MS/MS method met all criteria for accuracy, precision and stability, confirming its suitability for clinical use in monitoring ocrelizumab levels in multiple sclerosis patients.
Úvod: Lipoprotein(a) (Lp(a)) je donedávna přehlížený rizikový faktor, u něhož možná bude brzy k dispozici cílená léčba. Předpokládá se, že status Lp(a) je natolik stabilní, že bude vyžadovat pouze jedno stanovení za život. Cílem studie bylo ověřit toto v praxi. Metodika: Testovaný soubor zahrnuje celkem 490 ambulantních pacientů, u nichž byl opakovaně proveden náběr Lp(a), a posoudili jsme jeho intraindividuální variabilitu. Výsledky: Celkově bylo provedeno 1 657 jednotlivých stanovení Lp(a), při mediánu tři vyšetření na pacienta a odstupu mezi prvním a posledním stanovením 1,1 roku. Průměrný koeficient variability CVi (poměr směrodatných odchylek [SD] všech individuálních hodnot a jejich průměru) činil 18,2 %, medián rozdílu mezi dvěma hodnotami téhož pacienta 6,7 nmol/l (36,4 %), zatímco nejvyšší pozorovaný intraindividuální rozdíl až 228 nmol/l (86 %). Porovnávali jsme také, kolik pacientů dosáhlo hodnoty Lp(a) alespoň 175 nmol/l (potenciální kritérium léčby), při použití minimální a maximální individuální hodnoty. Při hodnotách Lp(a) < 75 nmol/l by variabilita stanovení ve směru indikace léčby žádný dopad neměla. Naopak u pacientů s Lp(a) ≥ 125 nmol/l by při použití nejnižší individuální hodnoty byla léčba indikována u 57 %, zatímco při použití nejvyšší hodnoty až u 88 % pacientů. V „šedé zóně“ 75–125 nmol/l by ke špatné klasifikaci z hlediska indikace léčby došlo jen u 15 % pacientů. Závěr: V praxi vykazuje Lp(a) poměrně vysokou intraindividuální variabilitu. Potenciální dopad z hlediska eventuální indikace k léčbě to ale má až u pacientů s hodnotou ≥ 125 nmol/l, kde je tedy namístě opakované stanovení tohoto parametru. Naopak u osob s Lp(a) < 75 nmol/l bude opravdu postačovat jedno screeningové vyšetření za život, jak je doporučováno.
Introduction: Lipoprotein(a) represents a virtually overlooked risk factor for which targeted treatment may be available soon. It has been suggested that Lp(a) concentrations are stable over time and need to be mea- sured only once in a lifetime. We aimed to verify this in clinical practice. Methods: The study includes 490 patients in whom Lp(a) was repeatedly collected, and we assessed its intra-individual variability. Results: A total of 1657 individual Lp(a) determinations were performed, with a median of 3 examinations/patient and an interval between the first/last determination of 1.1 years. The mean coefficient of variability (CVi, ratio of the SD of all individual values and their mean) was 18.2%, the median intra-individual difference was 6.7 nmol/L (36.4%), while the highest observed difference was 228 nmol/L (86%). We also compared how many patients achieved 175 nmol/L (potential treatment cut-off), either by minimal or maximal individual value. If Lp(a) < 75 nmol/L, the factor variability would have no impact in this way. In patients with ≥ 125 nmol/L, treatment would be indicated by 57% using the lowest, while 88% using the highest individual value. In the "grey zone" of 75-125 nmol/L, only 15% of patients would be misclassified in this way.
- MeSH
- Adult MeSH
- Biological Variation, Individual * MeSH
- Middle Aged MeSH
- Humans MeSH
- Lipoprotein(a) * blood MeSH
- Heart Disease Risk Factors MeSH
- Diagnostic Screening Programs MeSH
- Aged MeSH
- Statistics as Topic MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Clinical Study MeSH
- Research Support, Non-U.S. Gov't MeSH
T-lineage acute lymphoblastic leukemia (T-ALL) accounts for about 15% of pediatric and about 25% of adult ALL cases. Minimal/measurable residual disease (MRD) assessed by flow cytometry (FCM) is an important prognostic indicator for risk stratification. In order to assess the MRD a limited number of antibodies directed against the most discriminative antigens must be selected. We propose a pipeline for evaluating the influence of different markers for cell population classification in FCM data. We use linear support vector machine, fitted to each sample individually to avoid issues with patient and laboratory variations. The best separating hyperplane direction as well as the influence of omitting specific markers is considered. Ninety-one bone marrow samples of 43 pediatric T-ALL patients from five reference laboratories were analyzed by FCM regarding marker importance for blast cell identification using combinations of eight different markers. For all laboratories, CD48 and CD99 were among the top three markers with strongest contribution to the optimal hyperplane, measured by median separating hyperplane coefficient size for all samples per center and time point (diagnosis, Day 15, Day 33). Based on the available limited set tested (CD3, CD4, CD5, CD7, CD8, CD45, CD48, CD99), our findings prove that CD48 and CD99 are useful markers for MRD monitoring in T-ALL. The proposed pipeline can be applied for evaluation of other marker combinations in the future.
- MeSH
- Precursor Cell Lymphoblastic Leukemia-Lymphoma * diagnosis MeSH
- Child MeSH
- Adult MeSH
- Humans MeSH
- Precursor T-Cell Lymphoblastic Leukemia-Lymphoma * diagnosis MeSH
- Flow Cytometry MeSH
- Neoplasm, Residual diagnosis MeSH
- T-Lymphocytes MeSH
- Check Tag
- Child MeSH
- Adult MeSH
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Non-polio enteroviruses (NPEV) cause significant disease worldwide. Population-based sero-surveillance, by measuring antibodies against specific NPEV types, provides additional information on past circulation and the prediction for future upsurges. Virus neutralisation assays (VNA), the current method of choice for measuring NPEV type specific antibodies, are not entirely standardised. Via the European Non-Polio Enterovirus Network, we organised a VNA quality assessment in which twelve laboratories participated. We provided five echovirus (E) types (E1, E18, E30 G2, E30 G6 and E6) and intravenous immunoglobulins (IVIG) as a sample for the NPEV VNA quality assessment. Differences in VNA protocols and neutralising Ab (nAb) titres were found between the participating laboratories with geometric coefficients of variation ranging from 10.3-62.9 %. Mixed-effects regression analysis indicated a small but significant effect of type of cell line used. Harmonisation of cell line passage number, however, did not improve variation between laboratories. Calibration by making use of a reference sample, reduced variation between laboratories but differences in nAb titres remained higher than two log2 dilution steps. In conclusion, sero-surveillance data from different laboratories should be compared with caution and standardised protocols are needed.
- MeSH
- Echovirus Infections virology epidemiology immunology MeSH
- Enterovirus Infections virology immunology MeSH
- Enterovirus B, Human * immunology MeSH
- Humans MeSH
- Neutralization Tests * methods standards MeSH
- Antibodies, Neutralizing * blood immunology MeSH
- Antibodies, Viral * blood immunology MeSH
- Seroepidemiologic Studies MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Europe MeSH
This study aims to explore: (1) the validity of post-exercise ultra-short-term heart rate variability (HRVust) after two different bouts of repeated sprint ability test (RSA), and (2) the relationship between HRVust measure and RSA performance. Twenty adolescent male futsal players voluntarily participated in this study (age: 17.65 ± 1.81 years, body height: 170.88 ± 4.98 cm, body weight: 61.78 ± 4.67 kg). The participants performed a standard RSA test (RSAstandard) and an RSA test with a 10% decrement of the best sprint time test (RSA10%decrement) on two separate occasions within a week. On both occasions, a 5-min resting electrocardiography was administered pre- and post-RSA exercise protocols. The first 30-s (HRVust30s), 60-s (HRVust60s), and 60-120-s (HRVust1-2min) were extracted and used to compare with the standard of 5-min HRV recording (HRVcriterion). The natural logarithm (ln) of the standard deviation of normal-to-normal intervals (SDNN) and root mean square of successive normal-to-normal interval differences (RMSSD) HRV indices were utilised to establish intraclass correlation coefficient (ICC2,1), coefficient of variation (%CV), and Pearson product-moment correlation (r). Results revealed the ICC values of HRVust lnSDNN (RSAstandard = 0.77-0.88; RSA10%decrement = 0.41-0.71) and lnRMSSD (RSAstandard = 0.81-0.86; RSA10%decrement = 0.57-0.82). Furthermore, significantly positive correlations between best sprint time and post-exercise HRVust indices were found in lnSDNN (r = 0.47-0.62; p < 0.05) and lnRMSSD (r = 0.45; p < 0.05). Additionally, a large CV of lnSDNN (RSAstandard = 32%-45%; RSA10%decrement = 29%-39%), lnRMSSD (RSAstandard = 50%-66%; RSA10%decrement = 48%-52%), and ratio (RSAstandard = 45%-126%; RSA10%decrement = 27%-45%) was found after the RSA protocols. In conclusion, the number of bouts of RSA exercise potentially influences the agreement of post-exercise time-domain HRVust indices to standard HRV measure.
- MeSH
- Running * physiology MeSH
- Exercise physiology MeSH
- Electrocardiography MeSH
- Humans MeSH
- Adolescent MeSH
- Athletic Performance physiology MeSH
- Heart Rate * physiology MeSH
- Exercise Test * methods MeSH
- Check Tag
- Humans MeSH
- Adolescent MeSH
- Male MeSH
- Publication type
- Journal Article MeSH
