Primary thromboprophylaxis in cancer outpatients - real-world evidence.

INTRODUCTION: Cancer-associated thrombosis (CAT) is a significant concern among patients with malignant diseases, leading to increased mortality. While current guidelines recommend primary thromboprophylaxis for venous thromboembolism (VTE) in medium-to-high-risk outpatients, this practice remains controversial. A better understanding of primary thromboprophylaxis is crucial, yet there is a lack of Real-World Evidence (RWE) in Portugal. AIMS: This RWE study aimed to elucidate primary thromboprophylaxis practices among cancer outpatients in Portugal. METHODS: A five-year observational multicentric study in eight Portuguese health institutions enrolled 124 adult cancer outpatients under primary thromboprophylaxis for VTE. The endpoints were CAT, bleeding, cancer progression and death. RESULTS: High thrombotic risk tumours were prevalent, with 57% (71) of the patients presenting with pancreatic and gastric cancers. Regarding primary thromboprophylaxis, 55% (68) received Low-Molecular-Weight Heparin (LMWH). VTE was presented in 11% (14) of the patients and major bleeding in 2% (2). Vascular compression, elevated D-dimer and previous VTE were significantly associated with VTE occurrence under primary thromboprophylaxis. The Onkotev model was shown to be the best risk assessment model (RAM) in this population (p = 0.007). CAT patients exhibited a lower progression-free survival than non-CAT patients (p = 0.021), while thrombosis did not influence overall survival (p = 0.542). CONCLUSION: Primary thromboprophylaxis in medium-to-high-risk cancer outpatients is a safe and effective practice in real-world settings. This study is the first Portuguese RWE on primary thromboprophylaxis, highlighting evidence for improving prophylactic strategies in this population.

Enhancing patient outcomes: the role of clinical utility in guiding healthcare providers in curating radiology AI applications.

With advancements in artificial intelligence (AI) dominating the headlines, diagnostic imaging radiology is no exception to the accelerating role that AI is playing in today's technology landscape. The number of AI-driven radiology diagnostic imaging applications (digital diagnostics) that are both commercially available and in-development is rapidly expanding as are the potential benefits these tools can deliver for patients and providers alike. Healthcare providers seeking to harness the potential benefits of digital diagnostics may consider evaluating these tools and their corresponding use cases in a systematic and structured manner to ensure optimal capital deployment, resource utilization, and, ultimately, patient outcomes-or clinical utility. We propose several guiding themes when using clinical utility to curate digital diagnostics.

Stride-to-stride variability is altered when running to isochronous visual cueing but remains unaltered with fractal cueing.

Running synchronised to external cueing is often implemented in both clinical and training settings, and isochronous cueing has been shown to improve running economy. However, such cueing disregards the natural stride-to-stride fluctuations present in human locomotion which is thought to reflect higher levels of adaptability. The present study aimed to investigate how alterations in the temporal structure of cueing affect stride-to-stride variability during running. We hypothesised that running using cueing with a fractal-like structure would preserve the natural stride-to-stride variability of young adults. Thirteen runners performed four 8-min trials: one uncued (UNC) trial and three cued trials presenting an isochronous (ISO), a fractal (FRC) and a random (RND) structure. Repeated measures ANOVAs were used to identify changes in the dependent variables. We have found no main effect on the cardiorespiratory parameters, whereas a significant main effect was observed in the temporal structure of stride-to-stride variability. During FRC, the participants were able to retain the fractal patterns of their natural locomotor variability observed during the UNC condition, while during the ISO and RND they exhibited more random of fluctuations (i.e., lower values of fractal scaling). Our results demonstrate that cueing based on the natural stride-to-stride fluctuations opens new avenues for training and rehabilitation.

Iron overload induces dysplastic erythropoiesis and features of myelodysplasia in Nrf2-deficient mice.

Iron overload (IOL) is hypothesized to contribute to dysplastic erythropoiesis. Several conditions, including myelodysplastic syndrome, thalassemia and sickle cell anemia, are characterized by ineffective erythropoiesis and IOL. Iron is pro-oxidant and may participate in the pathophysiology of these conditions by increasing genomic instability and altering the microenvironment. There is, however, lack of in vivo evidence demonstrating a role of IOL and oxidative damage in dysplastic erythropoiesis. NRF2 transcription factor is the master regulator of antioxidant defenses, playing a crucial role in the cellular response to IOL in the liver. Here, we crossed Nrf2-/- with hemochromatosis (Hfe-/-) or hepcidin-null (Hamp1-/-) mice. Double-knockout mice developed features of ineffective erythropoiesis and myelodysplasia including macrocytic anemia, splenomegaly, and accumulation of immature dysplastic bone marrow (BM) cells. BM cells from Nrf2/Hamp1-/- mice showed increased in vitro clonogenic potential and, upon serial transplantation, recipients disclosed cytopenias, despite normal engraftment, suggesting defective differentiation. Unstimulated karyotype analysis showed increased chromosome instability and aneuploidy in Nrf2/Hamp1-/- BM cells. In HFE-related hemochromatosis patients, NRF2 promoter SNP rs35652124 genotype TT (predicted to decrease NRF2 expression) associated with increased MCV, consistent with erythroid dysplasia. Our results suggest that IOL induces ineffective erythropoiesis and dysplastic hematologic features through oxidative damage in Nrf2-deficient cells.

Cholesterol redistribution triggered by CYP46A1 gene therapy improves major hallmarks of Niemann-Pick type C disease but is not sufficient to halt neurodegeneration.

Cholesterol 24-hydroxylase (CYP46A1) is an exclusively neuronal cytochrome P450 enzyme responsible for converting cholesterol into 24S-hydroxycholesterol, which serves as the primary pathway for eliminating cholesterol in the brain. We and others have shown that increased activity of CYP46A1 leads to reduced levels of cholesterol and has a positive effect on cognition. Therefore, we hypothesized that CYP46A1 could be a potential therapeutic target in Niemann-Pick type C (NPC) disease, a rare and fatal neurodegenerative disorder, characterized by cholesterol accumulation in endolysosomal compartments. Herein, we show that CYP46A1 ectopic expression, in cellular models of NPC and in Npc1tm(I1061T) mice by adeno-associated virus-mediated gene therapy improved NPC disease phenotype. Amelioration in functional, biochemical, molecular and neuropathological hallmarks of NPC disease were characterized. In vivo, CYP46A1 expression partially prevented weight loss and hepatomegaly, corrected the expression levels of genes involved in cholesterol homeostasis, and promoted a redistribution of brain cholesterol accumulated in late endosomes/lysosomes. Moreover, concomitant with the amelioration of cholesterol metabolism dysregulation, CYP46A1 attenuated microgliosis and lysosomal dysfunction in mouse cerebellum, favoring a pro-resolving phenotype. In vivo CYP46A1 ectopic expression improves important features of NPC disease and may represent a valid therapeutic approach to be used concomitantly with other drugs. However, promoting cholesterol redistribution does not appear to be enough to prevent Purkinje neuronal death in the cerebellum. This indicates that cholesterol buildup in neurons might not be the main cause of neurodegeneration in this human lipidosis.

Targeting ROS production through inhibition of NADPH oxidases.

NADPH oxidases (NOXs) are transmembrane enzymes that are devoted to the production of reactive oxygen species (ROS). In cancers, dysregulation of NOX enzymes affects ROS production, leading to redox unbalance and tumor progression. Consequently, NOXs are a drug target for cancer therapeutics, although current therapies have off-target effects: there is a need for isoenzyme-selective inhibitors. Here, we describe fully validated human NOX inhibitors, obtained from an in silico screen, targeting the active site of Cylindrospermum stagnale NOX5 (csNOX5). The hits are validated by in vitro and in cellulo enzymatic and binding assays, and their binding modes to the dehydrogenase domain of csNOX5 studied via high-resolution crystal structures. A high-throughput screen in a panel of cancer cells shows activity in selected cancer cell lines and synergistic effects with KRAS modulators. Our work lays the foundation for the development of inhibitor-based methods for controlling the tightly regulated and highly localized ROS sources.

Pattern recognition of hematological profiles of tumors of the digestive tract: an exploratory study.

Aims: In this study, we aimed to apply laboratory blood analysis to identify the hematological (based on hemoglobin concentration, erythrocytes, hematocrit, and RDW count) profiles associated with the most prevalent forms of digestive tract malignancies. Furthermore, we aimed to evaluate how these profiles contributed to distinguishing these tumors at diagnosis. Methods: We collected data from the date of ICD-10 diagnostic coding for C15 esophagus, C16 stomach, C18 colon, and C19 rectum tumors of 184 individuals. The statistical analysis and data visualization approaches, notably the heat map and principal component analysis (PCA), allowed for creating a summary hematological profile and identifying the most associated parameters for each pathologic state. Univariate and multivariate data modeling and ROC analysis were performed in both SPSS and Python. Results: Our data reveal unique patterns based on tumor development anatomical location, clustering the C18 colon and C19 rectum from the C15 esophagus and C16 stomach. We found a significant difference between C16 stomach carcinoma and the other tumors, which substantially correlated with raised RDW in conjunction with low hemoglobin concentration, erythrocytes, and hematocrit counts. In contrast, C18 colon carcinoma had the higher red blood cell count, allowing for the best classification metrics in the test set of the binary logistic regression (LR) model, accounting for an AUC of 0.77 with 94% sensitivity and 52% specificity. Conclusion: This study emphasizes the significance of adding hematological patterns in diagnosing these malignancies, which could path further investigations regarding profiling and monitoring at the point of care.

Stroke and physiological relationships during the incremental front crawl test: outcomes for planning and pacing aerobic training.

Purpose: This study aimed to evaluate the physiological responses associated with the stroke length (SL) and stroke rate (SR) changes as swimming velocity increases during an incremental step-test. Moreover, this study also aimed to verify if SL and SR relationships toward maximal oxygen uptake (V̇O2max), gas respiratory compensation point (RCP), exchange threshold (GET), and swimming cost can be applied to the management of endurance training and control aerobic pace. Methods: A total of 19 swimmers performed the incremental test until volitional exhaustion, with each stage being designed by percentages of the 400 m (%v400) maximal front crawl velocity. V̇O2max, GET, RCP, and the respective swimming velocities (v) were examined. Also, the stroke parameters, SL, SR, the corresponding slopes (SLslope and SRslope), and the crossing point (Cp) between them were determined. Results: GET and RCP corresponded to 70.6% and 82.4% of V̇O2max (4185.3 ± 686.1 mL min-1), and V̇O2 at Cp, SLslope, and SRslope were observed at 129.7%, 75.3%, and 61.7% of V̇O2max, respectively. The swimming cost from the expected V̇O2 at vSLslope (0.85 ± 0.18 kJ m-1), vSRslope (0.77 ± 0.17 kJ m-1), and vCp (1.09 ± 0.19 kJ m-1) showed correlations with GET (r = 0.73, 0.57, and 0.59, respectively), but only the cost at vSLslope and vCp correlated to RCP (0.62 and 0.69) and V̇O2max (0.70 and 0.79). Conclusion: SL and SR exhibited a distinctive pattern for the V̇O2 response as swimming velocity increased. Furthermore, the influence of SL on GET, RCP, and V̇O2max suggests that SLslope serves as the metabolic reference of heavy exercise intensity, beyond which the stroke profile defines an exercise zone with high cost, which is recommended for an anaerobic threshold and aerobic power training. In turn, the observed difference between V̇O2 at SRslope and GET suggests that the range of velocities between SL and SR slopes ensures an economical pace, which might be recommended to develop long-term endurance. The results also highlighted that the swimming intensity paced at Cp would impose a high anaerobic demand, as it is located above the maximal aerobic velocity. Therefore, SLslope and SRslope are suitable indexes of submaximal to maximal aerobic paces, while Cp's meaning still requires further evidence.

Reliability of Maximal Strength and Peak Rate of Force Development in a Portable Nordic Hamstrings Exercise Device.

The Nordic hamstring exercise (NHE) is a very popular exercise used to improve eccentric strength and prevent injuries. The aim of this investigation was to assess the reliability of a portable dynamometer that measures maximal strength (MS) and rate of force development (RFD) during the NHE. Seventeen physically active participants (34.8 ± 4.1 years; n = 2 women and n = 15 men) participated. Measurements occurred on two different days separated by 48-72 h. Test-retest reliability was calculated for bilateral MS and RFD. No significant test-retest differences were observed in NHE (test-retest [95% CI, confidence interval]) for MS [-19.2 N (-67.8; 29.4); p = 0.42] and RFD [-70.4 N·s-1 (-178.4; 37.8); p = 0.19]. MS showed high reliability (intraclass correlation coefficient [ICC] [95% CI], =0.93 [0.80-0.97] and large within-subject correlation between test and retest [r = 0.88 (0.68; 0.95)]. RFD displayed good reliability [ICC = 0.76 (0.35; 0.91)] and moderate within-subject correlation between test and retest [r = 0.63 (0.22; 0.85)]. Bilateral MS and RFD displayed a coefficient of variation of 3.4% and 4.6%, respectively, between tests. The standard error of measurement and the minimal detectable change for MS was 44.6 arbitrary units (a.u.) and 123.6 a.u., and 104.6 a.u. and 290.0 a.u. for peak RFD. This study shows that MS and RFD can be measured for NHE using a portable dynamometer. However, not all exercises are suitable to apply to determine RFD, so caution must be taken when analyzing RFD during NHE.

360 Health Analysis (H360)-A Comparison of Key Performance Indicators in Breast Cancer Management across Health Institution Settings in Portugal.

BACKGROUND: The increased focus on quality indicators (QIs) and the use of clinical registries in real-world cancer studies have increased compliance with therapeutic standards and patient survival. The European Society of Breast Cancer Specialists (EUSOMA) established QIs to assess compliance with current standards in breast cancer care. METHODS: This retrospective study is part of H360 Health Analysis and aims to describe compliance with EUSOMA QIs in breast cancer management in different hospital settings (public vs. private; general hospitals vs. oncology centers). A set of key performance indicators (KPIs) was selected based on EUSOMA and previously identified QIs. Secondary data were retrieved from patients' clinical records. Compliance with target KPIs in different disease stages was compared with minimum and target EUSOMA standards. RESULTS: A total of 259 patient records were assessed. In stages I, II, and III, 18 KPIs met target EUSOMA standards, 5 met minimum standards, and 8 failed to meet minimum standards. Compliance with KPIs varied according to the type of hospital (particularly regarding diagnosis) and disease stage. Although small differences were found in KPI compliance among institutions, several statistical differences were found among treatment KPIs according to disease stage, particularly in stage III. CONCLUSIONS: This study represents the first assessment of the quality of breast cancer care in different hospital settings in Portugal and shows that, although most QIs meet EUSOMA standards, there is room for improvement. Differences have been found across institutions, particularly between oncology centers and general hospitals, in diagnosis and compliance with KPIs among disease stages. Stage III showed the greatest variability in compliance with treatment KPIs, probably related to the lower specificity of the guidelines in this disease stage.

Emotional status of children aged 7 to 17 of health workers and in the general population during the COVID-19 pandemic: A cross-sectional comparative study in Belgium.

Background: We assessed the mental health of children and adolescents aged 7 to 17 and their parents immediately after the first wave of the COVID-19 pandemic. Method: A survey online was conducted in Belgium between May 29th and August 31st 2020. Results: (1) Anxious and depressive symptoms were self-reported by one out of four children and hetero-reported by parents for one out of five children; (2) Anxiety scores were higher in children compared to adolescents; (3) Social introversion scores were significantly higher in adolescents compared to children; (4) No significant differences for anxio-depressive symptoms were found between healthcare worker parents and the other parents. Children's self- or hetero-reported symptoms were not found to be connected to parents' professional activities. Conclusions: This cross-sectional survey adds evidence to the impact the COVID-19 pandemic has had on children's and adolescents' emotional state, in particular on their levels of anxiety and depression.

Objectif: Nous avons évalué la santé mentale d'enfants et d'adolescents âgés de 7 à 17 ans et de leurs parents immédiatement après la première vague de la pandémie de COVID-19. Méthodologie: Une enquête en ligne a été réalisée en Belgique entre le 29 mai et le 31 août 2020. Résultats: (1) Les symptômes anxieux et dépressifs étaient auto-déclarés par un enfant sur quatre et hétéro-déclarés par les parents pour un enfant sur cinq ; (2) Les scores d'anxiété étaient plus élevés chez les enfants par rapport aux adolescents ; (3) Les scores d'introversion sociale étaient significativement plus élevés chez les adolescents par rapport aux enfants ; (4) Aucune différence significative pour les symptômes anxio-dépressifs n'a été trouvée entre les parents travailleurs de la santé et les autres parents. Les symptômes auto- ou hétéro-déclarés par les enfants ne se sont pas avérés être liés aux activités professionnelles des parents. Conclusions: Cette enquête transversale ajoute des preuves de l'impact de la pandémie de COVID-19 sur l'état émotionnel des enfants et des adolescents, en particulier sur leurs niveaux d'anxiété et de dépression.

Sex-Specific Accumulated Oxygen Deficit During Short- and Middle-Distance Swimming Performance in Competitive Youth Athletes.

INTRODUCTION: Since sex-specific accumulated oxygen deficit (AOD) during high-intensity swimming remains unstudied, this study aimed to assess AOD during 50, 100, and 200 m front-crawl performances to compare the responses between sexes and analyse the effect of lean body mass (LBM). METHODS: Twenty swimmers (16.2 ± 2.8 years, 61.6 ± 7.8 kg, and 48.8 ± 11.2 kg LBM-50% males) performed 50, 100, and 200 m to determine accumulated oxygen uptake (V̇O2Ac). The swimmers also performed an incremental test from which five submaximal steps were selected to estimate the oxygen demand (V̇O2demand) from the V̇O2 versus velocity adjustment. V̇O2 was sampled using a gas analyser coupled with a respiratory snorkel. AOD was the difference between V̇O2demand and V̇O2Ac, and LBM (i.e. lean mass not including bone mineral content) was assessed by dual-energy X-ray absorptiometry (DXA). RESULTS: A two-way ANOVA evidenced an AOD increase with distance for both sexes: 19.7 ± 2.5 versus 24.9 ± 5.5, 29.8 ± 8.0 versus 36.5 ± 5.8, and 41.5 ± 9.4 versus 5.2 ± 11.9 ml × kg-1, respectively, for 50, 100, and 200 m (with highest values for females, P < 0.01). Inverse correlations were observed between LBM and AOD for 50, 100, and 200 m (r = - 0.60, - 0.38 and - 0.49, P < 0.05). AOD values at 10 and 30 s elapsed times in each trial decreased with distance for both sexes, with values differing when female swimmers were compared to males in the 200 m trial (at 10 s: 2.6 ± 0.6 vs. 3.4 ± 0.6; and at 30 s: 7.9 ± 1.7 vs. 10.0 ± 1.8 ml × kg-1, P < 0.05). CONCLUSION: LBM differences between sexes influenced AOD values during each trial, suggesting that reduced muscle mass in female swimmers plays a role on the higher AOD (i.e. anaerobic energy) demand than males while performing supramaximal trials.

Effects of kettlebell swing training on cardiorespiratory and metabolic demand to a simulated competition in young female artistic gymnasts.

We examined the effects of adding a Kettlebell Swing training program (KB) to the regular skill-training protocol (REGULAR) on cardiorespiratory fitness, cardiorespiratory/metabolic demand, and recovery to a simulated competition of female artistic gymnastics. Nine gymnasts (13±2 years) had their REGULAR complemented with a 4-week kettlebell training (REGULAR+KB), consisting of 3 sessions/week of 12x30" swings x 30" rest with » of their body weight, while 9 aged-matched gymnasts acted as a comparison group. Peak oxygen uptake ([Formula: see text]) during routines was estimated from the O2 recovery curve using backward extrapolation and off-kinetics parameters were modeled through a mono-exponential function. Heart rate (HR) was monitored continuously and capillary blood lactate (BLa-) was measured before and after each routine (1st and 3rd min). Cardiorespiratory fitness ([Formula: see text]) was evaluated using a ramp cycle ergometer test. A training-by-time interaction effect was observed for [Formula: see text] (p = 0.009) as increments were only observed after REGULAR+KB (M = 8.85, SD = 9.67 ml.kg.min-1). No training-by-time interactions were observed for HRpeak (p = 0.39), [Formula: see text] (p = 0.07), or La-post3 (p = 0.25), both training protocols reduced HRpeak (M = -12; SD = 11 b.min-1) and BLa-post1 (M = -0.70; SD = 1.29 mmol.L-1) during the simulated competition, but not relative [Formula: see text]. No training-by-time interaction was observed for the off-transient [Formula: see text] time constant (p = 0.38). [Formula: see text] recovery was slower (M = 5; SD = 10 s) after both protocols. Both training protocols improved cardiorespiratory and metabolic demands and recovery kinetics to a simulated competition of female artistic gymnastics, although increases in cardiorespiratory fitness were only observed in REGULAR+KB.

Dimensional model on how familial vulnerability and environmental factors impact transitional age youth psychopathology: The Transition_psy study.

Background: Understanding psychopathology in transitional age youth (TAY) requires a complex model, incorporating familial vulnerability and environmental factors. A trans-diagnostic and dimensional approach seems the most appropriate. Transition_psy study aims to assess factors playing a role in TAY psychopathology and to define predictors. Materials and methods: This article presents part of the Transition_psy study results, a case-control observational study. Youth aged 17 years old were recruited between June 2020 and December 2021, from both clinical [clinical population (CP) group] and non-clinical settings [non-clinical population (NCP) group]. Participants completed self-report questionnaires. The primary outcome to assess TAY psychopathology was the Youth-Self Report (YSR). We evaluated care needs with the Health of The Nation Outcome Scales For Children And Adolescents (HoNOSCA-SR) and quality of life with the World Health Organization Quality of Life - BREF (WHOQoL-BREF). Exposure factors included familial vulnerability, childhood, and present environmental factors, such as first-degree family history of psychopathology, the Childhood Trauma Questionnaire (CTQ) and the Family Assessment Device (FAD). YSR scores were compared, between groups, according to exposure factors with ANOVA and linear regression. We performed best subsets selection of multivariable analyses based on the Akaike Information Criterion. This study was registered with ClinicalTrials.gov (Identifier: NCT04333797). Results: A total of 220 TAY (CP = 106, NCP = 114) were included in the study. Participants were aged 17 years old. The majority were female (69.1%), single (96.8%), and born in Belgium (82.3%). Clinical data were all significantly different between CP and NCP groups. YSR scores were found statistically different according to group (p < 0.001), first-degree family history of psychopathology (p < 0.001), CTQ (p < 0.001), and FAD (p < 0.001). Predictive dimensional model suggested that TAY psychopathology can be predicted by group, CTQ and FAD. Significant positive correlation was found between YSR and HoNOSCA (rho = 0.81) and negative correlation between YSR and physical and psychological health (rho = -0.69 and -0.71, respectively). Conclusion: This study findings allowed to present a predictive dimensional model on TAY psychopathology, including belonging to a clinical population at transitional age, childhood trauma, and family dysfunction. Further research is needed to replicate Transition_psy study results in other samples. The proposed model could be used in clinical practice to improve assessment of TAY psychopathology.

Anticipatory cues in emotional processing shift the activation of a combined salience sensorimotor functional network in drug-naïve depressed patients.

BACKGROUND: Major depressive disorder is characterized by a large-scale brain network dysfunction, contributing to impairments in cognitive and affective functioning. Core regions of default mode, limbic and salience networks are also impaired in emotional processing and anticipation. This study aimed to explore default mode, salience, and limbic networks modulation during the processing of emotional stimuli with and without anticipatory cues in depression, and further investigate how these networks were functionally coupled with the rest of the brain. METHODS: Twenty-one drug-naïve depressed patients and 15 matched controls were included in the study. All participants completed a psychological assessment and the affective pictures paradigm during an fMRI acquisition. Group independent component analysis and psychophysiological interactions analyses were performed. RESULTS: A significant interaction between Cue, Valence and Group was found for the salience/sensorimotor network. When processing uncued emotional stimuli, patients showed increased activation of this network for negative vs. neutral pictures, whereas when anticipatory cues were displayed previously to the picture presentation, they invert this pattern of activation (hyperactivating the salience/sensorimotor network for positive vs. neutral pictures). Patients showed increased functional connectivity between the salience/sensorimotor network and the left amygdala as well as the right inferior parietal lobule compared to controls when processing uncued negative pictures. LIMITATIONS: The sample size was modest, and the salience/sensorimotor network included regions not typically identified as part of salience network. Thus, this study should be replicated to further interpret the results. CONCLUSIONS: Anticipatory cues shift the pattern of activation of the salience/sensorimotor network in drug-naïve depressed patients.

The Peroxidase-Coupled Assay to Measure MAO Enzymatic Activity.

MAO activity measurement is generally performed following different spectroscopy methods, in most cases using peroxidase as a coupled reaction catalyst. In the presence of horseradish peroxidase (HRP), the assay follows the oxidation of the typical MAO substrate (aromatic amines) which generates hydrogen peroxide as a secondary product. There are several chromogens and fluorogens that, in the presence of hydrogen peroxide, are converted by HRP to detectable products. In the present chapter we describe the spectrophotometric 4-aminoantipyrine assay as well as the fluorogenic assay with the Amplex® Red chemical probe. These methods are applied on MAO activity and Michaelis-Menten curve determinations as well as inhibitory activity experiments.

Measurement of MAO Enzymatic Activity by Spectrophotometric Direct Assays.

MAO activity measurement can be monitored by direct peroxidase-free assays following different spectroscopy methods. Typically, these are assays that follow the conversion of different MAO substrates into its corresponding products monitored in either absorbance or fluorescence. Herein, we describe the assays for enzyme activity assessment with MAO B and particularly the MAO A substrate kynuramine, as well as the MAO B substrate benzylamine. Moreover, we also describe MAO activity determination using the tertiary amine substrate allyl amine 1-methyl-4-(1-methyl-1 H-pyrrol-2-yl)-1,2,3,6-tetrahydropyridine (MMTP). These are very useful methods for the investigation of MAO inhibitory activity by molecules known to be HRP-interfering. In the present chapter we demonstrate the application of these methods in MAO activity and Michaelis-Menten curve determinations as well as inhibitory activity experiments.

In-situ acceleration-speed profile of an elite soccer academy: A cross-sectional study.

Speed is an essential skill in sports performance and an important performance metric in talent identification. This study aims to evaluate and compare the sprint acceleration characteristics across different age groups in an elite soccer academy. A total of 141 elite academy soccer players were recruited to participate in the study, and they were assigned to their respective competitive age groups, ranging from under-14 to the B-team. An individual in-situ acceleration-speed (A-S) profile was assessed and derived from Global Position System (GPS) speed-acceleration raw data, from 10 consecutive football sessions, in the beginning of the season. The results showed that under-14 players exhibited significantly lower theoretical maximum speed (S0) (ηp2 = 0.215, p < 0.01) when compared with all other age groups. However, no differences were found between maximum theoretical acceleration (A0) and A-S slope between age groups. The results suggest that sprint mechanical profiles of young soccer athletes remain stable throughout their athletic development. Nevertheless, younger athletes have less capacity to apply horizontal force at higher speeds (S0).