The biological variation of serum 1,25-dihydroxyvitamin D and parathyroid hormone, and plasma fibroblast growth factor 23 in healthy individuals.

BACKGROUND AND AIMS: Measuring 1,25-dihydroxyvitamin D (1,25(OH)2D), parathyroid hormone 1-84 (PTH 1-84) and intact FGF23 (iFGF23) is crucial for diagnosing a variety of diseases affecting bone and mineral homeostasis. Biological variability (BV) data are important for defining analytical quality specifications (APS), the usefulness of reference intervals, and the significance of variations in serial measurements in the same subject. The aim of this study was to pioneer the provision of BV estimates for 1,25(OH)2D and to improve existing BV estimates for iFGF23 and PTH 1-84. MATERIALS AND METHODS: Serum and plasma-EDTA samples of sixteen healthy subjects have been collected for seven weeks and measured in duplicate by chemiluminescent immunoassay on the DiaSorin Liaison platform. After variance verification, within-subject (CVI) and between-subject (CVG) BV estimates were assessed by either standard ANOVA, or CV-ANOVA. The APSs were calculated according to the EFLM-BV-model. RESULTS: We found the following CVI estimates with 95% confidence intervals:1,25(OH)2D, 22.2% (18.9-26.4); iFGF23, 16.1% (13.5-19.5); and PTH 1-84, 17.9% (14.8-21.8). The CVG were: 1,25(OH)2D, 21.2% (14.2-35.1); iFGF23, 21.1% (14.5-35.8); and PTH 1-84, 31.1% (22.1-50.8). CONCLUSIONS: We report for the first time BV estimates for 1,25(OH)2D and enhance existing data about iFGF23-BV and PTH 1-84-BV through cutting-edge immunometric methods.

Cervical anterior spinal artery infarction associated with anomalous vertebral artery: a case report.

We report a unique case of cervical anterior spinal artery (ASA) infarction in a 49-year-old male with hypercholesterolemia and sleep apnea. The patient experienced sudden cervical pain, quadriparesis, areflexia, and urinary incontinence after swallowing a large food bolus. Imaging revealed an infarction at the C3-C5 levels and an anomalous right vertebral artery (VA) originating from the thoracic aorta, tightly enclosed between the aorta and a vertebral column with an anterior osteophyte. This aberrant VA was the primary vascular supply to the ASA, with no contribution from the left VA or supreme intercostal arteries. We propose that transient injury to the right VA, induced by compression between the aortic arch, the food bolus, and the osteophyte, led to temporary hypoperfusion of the ASA, causing a watershed ischemic injury in the mid cervical cord's anterior gray matter. The article also provides an in-depth discussion of the developmental and clinical characteristics associated with this rare vascular anomaly.

Identification of metabolites generated in the biotransformation process by the Danio rerio (zebrafish) exposed to the fungicide tebuconazole.

Tebuconazole is a triazole fungicide widely used in agricultural crops for control of multiple fungal, mainly foliar and soil-borne diseases. Due to its intense use, this pesticide has been detected on aquatic matrices in different countries, which makes it necessary to identify metabolites capable to be used in its exposure monitoring. The aim of this work was to evaluate tebuconazole metabolites in zebrafish water tanks using liquid chromatography coupled to a high-resolution mass spectrometer (LCHRMS) to highlight analytical targets to monitor tebuconazole exposure in aquatic environments. Two Phase I metabolites, TEB-OH and TEB-COOH, and one Phase II metabolite, TEB-S, were identified. Target metabolomics pointed TEB-S as the most important metabolite for discrimination between treatment and negative control group and potential surrogate for detection and monitoring of tebuconazole exposure in aquatic environments. To the best of our knowledge, this is the first study to suggest the sulphation of tebuconazole (TEB-S) by zebrafish metabolism. Moreover, the use of water samples proved to be a promising approach when compared to the usual biological matrices (e.g. plasma) for evaluating the exposure of aquatic animals to tebuconazole because it is a clean and easy to obtain matrix. Water samples presented a higher concentration of metabolites when compared to plasma samples. The results suggest the applicability of this assay model for the identification of potential biomarkers for monitoring the presence of xenobiotics in water.

Vericiguat: The Fifth Harmony of Heart Failure with Reduced Ejection Fraction.

Heart failure with reduced ejection fraction is a chronic and progressive syndrome that continues to be a substantial financial burden for health systems in Western countries. Despite remarkable advances in pharmacologic and device-based therapy over the last few years, patients with heart failure with reduced ejection fraction have a high residual risk of adverse outcomes, even when treated with optimal guideline-directed medical therapy and in a clinically stable state. Worsening heart failure episodes represent a critical event in the heart failure trajectory, carrying high residual risk at discharge and dismal short- or long-term prognosis. Recently, vericiguat, a soluble guanylate cyclase stimulator, has been proposed as a novel drug whose use is already associated with a reduction in heart failure-related hospitalizations in patients in guideline-directed medical therapy. In this review, we summarized the pathophysiology of the nitric oxide-soluble guanylate cyclase-cyclic guanosine monophosphate cascade in patients with heart failure with reduced ejection fraction, the pharmacology of vericiguat as well as the evidence regarding their use in patients with HFrEF. Finally, tips and tricks for its use in standard clinical practice are provided.

How to Select Patients for Left Ventricular Assist Devices? A Guide for Clinical Practice.

In recent years, a significant improvement in left ventricular assist device (LVAD) technology has occurred, and the continuous-flow devices currently used can last more than 10 years in a patient. Current studies report that the 5-year survival rate after LVAD implantation approaches that after a heart transplant. However, the outcome is influenced by the correct selection of the patients, as well as the choice of the optimal time for implantation. This review summarizes the indications, the red flags for prompt initiation of LVAD evaluation, and the principles for appropriate patient screening.

The ABC of Heart Transplantation-Part 1: Indication, Eligibility, Donor Selection, and Surgical Technique.

Cardiac transplantation represents the gold standard of treatment for selected patients with advanced heart failure who have poor functional capacity and prognosis despite guideline-directed medical therapy and device-based therapy. Proper patient selection and appropriate referral of patients to centers for the treatment of advanced heart failure are the first but decisive steps for screening patients eligible for cardiac transplantation. The eligibility and the decision to list for cardiac transplantation, even for patients with relative contraindications, are based on a multidisciplinary evaluation of a transplant team. This review will discuss the practical indications, the process of patient eligibility for cardiac transplantation, the principle of donor selection, as well as the surgical technique.

Pathophysiology-Based Management of Acute Heart Failure.

Even though acute heart failure (AHF) is one of the most common admission diagnoses globally, its pathogenesis is poorly understood, and there are few effective treatments available. Despite an heterogenous onset, congestion is the leading contributor to hospitalization, making it a crucial therapeutic target. Complete decongestion, nevertheless, may be hard to achieve, especially in patients with reduced end organ perfusion. In order to promote a personalised pathophysiological-based therapy for patients with AHF, we will address in this review the pathophysiological principles that underlie the clinical symptoms of AHF as well as examine how to assess them in clinical practice, suggesting that gaining a deeper understanding of pathophysiology might result in significant improvements in HF therapy.

Untargeted Metabolomics Reveals Lipid Impairment in the Liver of Adult Zebrafish (Danio rerio) Exposed to Carbendazim.

Carbendazim is a systemic fungicide used in several countries, particularly in Brazil. However, studies suggest that it is related to the promotion of tumors, endocrine disruption, and toxicity to organisms, among other effects. As a result, carbendazim is not allowed in the United States, Australia, and some European Union countries. Therefore, further studies are necessary to evaluate its effects, and zebrafish is a model routinely used to provide relevant information regarding the acute and long-term effects of xenobiotics. In this way, zebrafish water tank samples (water samples from aquari containing zebrafish) and liver samples from animals exposed to carbendazim at a concentration of 120 µg/L were analyzed by liquid chromatography coupled to high-resolution mass spectrometry, followed by multivariate and univariate statistical analyses, using the metabolomics approach. Our results suggest impairment of lipid metabolism with a consequent increase in intrahepatic lipids and endocrine disruption. Furthermore, the results suggest two endogenous metabolites as potential biomarkers to determine carbendazim exposure. Finally, the present study showed that it is possible to use zebrafish water tank samples to assess the dysregulation of endogenous metabolites to understand biological effects. Environ Toxicol Chem 2023;42:437-448. © 2022 SETAC.

Effects of Cardiac Contractility Modulation Electrodes on Tricuspid Regurgitation in Patients with Heart Failure with Reduced Ejection Fraction: A Pilot Study.

BACKGROUND: Cardiac contractility modulation (CCM) is an innovative therapy for heart failure with reduced ejection fraction delivered by a cardiac implantable device (Optimizer Smart®). One of the most prominent periprocedural complications common to all cardiac implantable devices (CIDs) is tricuspid regurgitation (TR) due to the placement of the right ventricular endocardial leads. To date, no published studies have assessed the changes in the TR degree in patients with heart failure with reduced ejection fraction (HFrEF) who received an implantable cardioverter-defibrillator (ICD) after the implantation of cardiac contractility modulation therapy devices. OBJECTIVE: This study aimed to evaluate the effect of the implantation of the trans-tricuspid leads required to deliver CCM therapy on the severity of TR in patients with HFrEF who previously underwent ICD implantation. METHODS: We enrolled 30 HFrEF patients who underwent CCM therapy between November 2020 and October 2021. For all the patients, echocardiographic evaluations of TR were performed according to current guidelines 24 h before and six months after the Optimizer Smart® implant was applied. RESULTS: At the 6-month follow-up, the grade of TR remained unchanged compared to the preimplant grade. The value of the vena contracta (VC) of TR was 0.40 ± 0.19 cm in the preimplant period and 0.45 ± 0.21 cm at the 6-month follow-up (p = 0.33). Similarly, the TR proximal isovelocity surface area (PISA) radius value was unchanged at follow-up (0.54 ± 0.22 cm vs. 0.62 ± 0.20 cm; p = 0.18). No statistically significant difference existed between the preimplant VC and PISA radius values, irrespective of the device type. CONCLUSIONS: The implantation of right ventricular electrodes for the delivery of CCM therapy did not worsen tricuspid regurgitation in patients with HFrEF and ICD.

The Effects of Device-Based Cardiac Contractility Modulation Therapy on Left Ventricle Global Longitudinal Strain and Myocardial Mechano-Energetic Efficiency in Patients with Heart Failure with Reduced Ejection Fraction.

BACKGROUND: Virtually all patients with heart failure with reduced ejection fraction have a reduction of myocardial mechano-energetic efficiency (MEE). Cardiac contractility modulation (CCM) is a novel therapy for the treatment of patients with HFrEF, in whom it improves the quality of life and functional capacity, reduces hospitalizations, and induces biventricular reverse remodeling. However, the effects of CCM on MEE and global longitudinal strain (GLS) are still unknown; therefore, this study aims to evaluate whether CCM therapy can improve the MEE of patients with HFrEF. METHODS: We enrolled 25 patients with HFrEF who received an Optimizer Smart implant (the device that develops CCM therapy) between January 2018 and January 2021. Clinical and echocardiographic evaluations were performed in all patients 24 h before and six months after CCM therapy. RESULTS: At six months, follow-up patients who underwent CCM therapy showed an increase of left ventricular ejection fraction (30.8 ± 7.1 vs. 36.1 ± 6.9%; p = 0.032) as well a rise of GLS 10.3 ± 2.7 vs. -12.9 ± 4.2; p = 0.018), of MEE (32.2 ± 10.1 vs. 38.6 ± 7.6 mL/s; p = 0.013) and of MEE index (18.4 ± 6.3 vs. 24.3 ± 6.7 mL/s/g; p = 0.022). CONCLUSIONS: CCM therapy increased left ventricular performance, improving left ventricular ejection fraction, GLS, as well as MEE and MEEi.

Anxiolytic effect of Anthemis nobilis L. (roman chamomile) and Citrus reticulata Blanco (tangerine) essential oils using the light-dark test in zebrafish (Danio rerio).

ETHNOPHARMACOLOGICAL RELEVANCE: The anxiety disorders are the most prevalent mental health condition, and anxiety is considered the sixth cause of disability surpassing diabetes mellitus, chronic obstructive pulmonary disease, and osteoarthritis. Besides, the COVID-19 pandemic provided an increase in the number of psychiatric diseases diagnosis in all social layers around the world. About 55%-94% of patients diagnosed with anxiety disorders are treated with benzodiazepines, meanwhile benzodiazepines can promote several adverse effects. In this way, alternative therapies, such as essential oils may offer significant benefits in the treatment of patients with anxiety disorders. However, the anxiolytic effect of these essential oils must be proper evaluated appropriate as well as the suitable dosage and side effect need further research. AIM OF THE STUDY: The aim was to evaluate the anxiolytic effect of Roman chamomile (Anthemis nobilis L.) and tangerine (Citrus reticulata Blanco) essential oils using the light-dark test in adult zebrafish (Danio rerio). MATERIAL AND METHODS: Both essential oils were analyzed by GC-MS and the major compounds were identified. The anxiolytic effect was evaluated by light-dark test in adult zebrafish. RESULTS: The results showed that roman chamomile essential oil has anxiolytic effect in adult zebrafish, whereas tangerine essential oil tends to reduce anxiety The major compounds of tangerine essential oil were limonene and γ-terpinene, and the major compounds of roman chamomile were pentadecyl-3-methyl-2-butenoate, hexadecyl-3-methyl-2-butenoate, 1-piperidinol and trans-1-ethyl-3-methyl-cyclopentane. CONCLUSIONS: The present study demonstrated that this anxiolytic effect may be attributed to the synergistic effect of the compounds present in roman chamomile essential oil, particularly the major compounds. The roman chamomile essential oil at the highest concentration showed anxiolytic effect. The tangerine essential oil showed a tendency to reduce anxiety, but it was not statistically significative. In addition, roman chamomile and tangerine essential oils did not cause cause alteration in locomotion activity and exploratory ability of the fish.

Levosimendan as a "Bridge to Optimization" in Patients with Advanced Heart Failure with Reduced Ejection-A Single-Center Study.

Background: Patients with advanced heart failure with reduced ejection fraction often cannot tolerate target doses of guideline-directed medical therapy due to symptomatic hypotension, renal dysfunction, and associated electrolyte abnormalities. While levosimendan can facilitate the titration of ß-blockers in patients with advanced HFrEF, it is unclear whether ambulatory levosimendan infusions would offer the same benefit. In this prospective study, we investigate the effects of intermittent ambulatory levosimendan infusions on the uptitration of disease-modifying drugs. Methods: We enrolled 37 patients with advanced HFrEF who received repeated ambulatory infusions of levosimendan between January 2018 and January 2021. The demographic, clinical, and laboratory data were acquired 24 h before the first and the last ambulatory levosimendan infusion. Results: At the 1 year follow-up, the enrolled patients were on significantly higher doses of guideline-directed medical therapy, including bisoprolol (3.2 ± 2.8 mg vs. 5.9 ± 4.1 mg; p = 0.02), sacubitril/valsartan (41.67 ± 32.48 mg vs. 68.5 ± 35.72 mg; p = 0.01), and eplerenone (12.7 ± 8.5 mg vs. 22.8 ± 13.6 mg; p = 0.03). Furthermore, a substantial decrease in the furosemide dose was observed (123.2 ± 32.48 mg vs. 81.6 ± 19.47 mg; p < 0.0001). Conclusions: Levosimendan facilitates the optimization of disease-modifying heart failure medications in previously intolerant advanced HFrEF patients.

Critical Issues of Working during the COVID-19 Pandemic: Italian Healthcare Workers' Experience.

Background: The COVID-19 pandemic has strongly impacted on healthcare services' organization and healthcare workers' mental health, increasing the risk of psychological symptoms and burnout. Italy has been one of the most affected countries, especially the northern regions, even with exceptions in some rural provinces. Aim: We chose to investigate the mental health conditions of healthcare workers operating in the rural province of Rovigo (a small town in Veneto, northern Italy), where relatively few deaths and contagions were reported during the pandemic, even if Veneto-globally-was one of the most affected regions of Italy. We wanted to verify the psychological outcomes of health workers operating in a context where the impact of the pandemic appeared to be relatively mild. Methods: Through an online survey, we investigated perceived difficulties at work and in daily life, perceived loneliness and social support, coping strategies, and level of psychological distress (sample size: 749; mean age = 48.04 years, SD = 10.66). The questionnaire had both open- (2) and close-ended questions (5 single-choice and 13 multiple-choice). We verified possible associations between sex, age group, work department and percentage of responses with chi-square tests of independence on each question. Data cleaning excluded all contradictory answers from the multiple-choice questions from the analyses (final sample size: 640). Results: Frontliners and non-frontliners reported a similar experience of the COVID-19 pandemic (without significant differences in perceived difficulties, coping strategies and sources of support). Nevertheless, they still reported various forms of negative emotions (e.g., helplessness-40.94%; sadness-36.56%; frustration-32.66%) and lack of support from the health organization (especially frontliners-28.72%). However, psychological help was scarcely requested. Conclusions: Despite the province not being massively affected by the pandemic, healthcare workers felt the need for clearer and more supportive guidance. They seem to perceive collective opportunities to share needs and difficulties as more useful than individual interventions (as those provided by the ad hoc created listening service).

Hemodynamic Effects of Levosimendan in Outpatients With Advanced Heart Failure: An Echocardiographic Pilot Study.

ABSTRACT: Infusions of levosimendan delivered in ambulatory/outpatient settings have been shown to improve quality of life and reduce hospitalizations in patients with advanced heart failure (HF). The aim of this pilot study was to evaluate the effects of ambulatory infusion of levosimendan on echocardiographic markers of perfusion, congestion, and cardiovascular efficiency. Thirty patients with diagnosed advanced HF underwent ambulatorial infusion of levosimendan at a total dose of 6.25 mg as a part of a repetitive biweekly treatment strategy with the inotrope. Standardized transthoracic echocardiography and Doppler examinations, were performed 1 hour before and 48 hours after completion of ambulatory infusion. At 48 hours after ambulatory infusion of levosimendan, a significant increase in the stroke volume (37.47 ± 12.38 mL/beat vs. 45.47 ± 14.48 mL/beat; P < 0.05) and cardiac output (2.64 ± 0.66 L/min vs. 3.26 ± 0.57 L/min; P < 0.05) occurred. Significant postreductions versus prereductions were also recorded in left atrial pressure (27.37 ± 6.62 mm Hg vs. 22.82 ± 4.17 mm Hg; P < 0.01), mean pulmonary artery pressure (27.69 ± 4.64 mm Hg vs. 23.24 ± 5.32; P < 0.01), and inferior vena cava diameter (23.81 ± 7.63 mm vs. 18.53 ± 4.82 mm; P < 0.01). Significant improvements were noted in the resting cardiac power output (0.46 ± 0.15 watt vs. 0.53 ± 0.22 watt; P < 0.01) and the resting cardiac power index (0.24 ± 0.08 watt/m2 vs. 0.28 ± 0.11 watt/m2; P < 0.01). In outpatients with advanced HF, infusion of levosimendan was associated with hemodynamic responses that may contribute to the clinical benefit previously reported in such patients.

Caring for Caregivers: Italian Health Care Workers' Needs during the COVID-19 Pandemic.

Aim: An online survey was proposed to the health workers of a public hospital of an Italian northern city. This was done with the aim of assessing the unmet needs of a special population under strain (the health carers) due to the fight against the coronavirus disease 19 (COVID-19). Results: By answering the survey, five hundred and nine people provided their observations, complaints and suggestions. This qualitative material was organised into three main areas: (1) relationship with the health organization management; (2) needs of the health workers; and (3) perceived consequences of the pandemic. Discussion: Overall, respondents expressed dissatisfaction for the unpreparedness of their health units and the confusion created by frequent changes in operational guidelines. Many participants felt abandoned, unheard and unprotected by the health organization, whilst the psychological support service formally set up by the hospital for its health workers was grossly under-utilised. Instead, support from colleagues and family constituted the main protective factor to counteract negative emotions. Restrictions in social contacts and recreational opportunities were frequently mentioned. Several respondents reported a sense of pride for their work and commitment; many others saw in the pandemic an opportunity for personal growth and better focus on important life values, like family and solidarity.

Inotropes in Patients with Advanced Heart Failure: Not Only Palliative Care.

Patients with advanced heart failure suffer from severe and persistent symptoms, often not responding disease-modifying drugs, a marked limitation of functional capacity and poor quality of life that can ameliorate with inotropic drugs therapy. In small studies, pulsed infusions of classical inotropes (ie, dobutamine and milrinone) are associated with improvement in hemodynamic parameters and quality of life in patients with advanced heart failure. However, because of the adverse effects of these drugs, serious safety issues have been raised. Levosimendan is a calcium-sensitizing inodilators with a triple mechanism of action, whose infusion results in hemodynamic, neurohormonal, and inflammatory cytokine improvements in patients with chronic advanced HF. In addition, levosimendan has important pleiotropic effects, including protection of myocardial, renal, and liver cells from ischemia-reperfusion injury, and anti-inflammatory and antioxidant effects; these properties possibly make levosimendan an "organ protective" inodilator. In clinical trials and real-world evidence, infusion of levosimendan at fixed intervals is safe and effective in patients with advanced HF, alleviating clinical symptoms, reducing hospitalizations, and improving the quality of life. Therefore, the use of repeated doses of levosimendan could represent the therapy of choice as a bridge to transplant/left ventricular assist device implantation or as palliative therapy in patients with advanced heart failure.

The Use of ß-Blockers in Heart Failure with Reduced Ejection Fraction.

Treatment with ß-blockers is the main strategy for managing patients with heart failure and reduced ejection fraction because of their ability to reverse the neurohumoral effects of the sympathetic nervous system, with consequent prognostic and symptomatic benefits. However, to date, they are underused, mainly because of the misconception that hypotension and bradycardia may worsen the haemodynamic status of patients with HFrEF and because of the presence of comorbidities falsely believed to be absolute contraindications to their use. To promote proper use of ß-blockers in this article, we review the clinical pharmacology of ß-blockers, the evidence of the beneficial effects of these drugs in heart failure with reduced ejection fraction, and the current guidelines for their use in clinical practice and in the presence of comorbidities (e.g., pulmonary disease, diabetes, atrial fibrillation, peripheral arterial disease, etc.). It is hoped that the practical approach discussed in this review will allow for a proper diffusion of knowledge about the correct use of ß-blockers and the drug-disease interactions to achieve their increased use and titration, as well as for the selection of a specific agent with a view to a properly tailored approach for HFrEF patients.

Serum 25-hydroxyvitamin D measurement: Comparative evaluation of three automated immunoassays.

OBJECTIVES: the different analytical methods for measurement of serum 25-hydroxyvitamin D (25(OH)D) are not yet fully harmonized and no consensus exists on a threshold of 25(OH)D defining a deficiency status. In this study, we compared the results from the assays of serum 25(OH)D performed with three different methods to evaluate the presence of potential biases and how much these biases can influence the assignment of patients to specific 25(OH)D deficiency/sufficiency categories. DESIGN AND METHODS: Liaison 25(OH) Vitamin D Total (DiaSorin Liaison XL), Elecsys Vitamin D Total II (Roche Elecsys) and Lumipulse G25(OH) Vitamin D (Fujirebio Lumipulse G1200) were used. Methods comparability was established performing Passing-Bablok regression and Bland-Altman analysis to prove whether the differences found were lower than the preliminarily pre-established maximum acceptable bias. RESULTS: all Passing-Bablok regressions exhibited the presence of a proportional and constant systematic error. Bland-Altman analysis revealed biases well above the maximum acceptable bias, so the 25(OH)D concentrations measured were not comparable. To evaluate whether the three methods had the same ability to classify patients into different categories of vitamin D levels, we categorized results obtained by each method in reference classes. Lumipulse categorized most patients into the class with the lowest 25(OH)D concentrations (<20 ng/mL) whereas Elecsys ranked the lowest number. CONCLUSIONS: Liaison XL and Elecsys have shown good accuracy compared to Lumipulse in measuring 25(OH)D levels. Nevertheless, the assays were not interchangeable due to the lack of comparability of results as well as to the disagreement in classification of hormone deficiency or sufficiency.

Evaluation of Dermorphin Metabolism Using Zebrafish Water Tank Model and Human Liver Microsomes.

BACKGROUND: Dermorphin is a heptapeptide with an analgesic potential higher than morphine that does not present the same risk for the development of tolerance. These pharmacological features make dermorphin a potential doping agent in competitive sports and it is already prohibited for racehorses. For athletes, the development of an efficient strategy to monitor for its abuse necessitates an investigation of the metabolism of dermorphin in humans. METHODS: Here, human liver microsomes and zebrafish were utilized as model systems of human metabolism to evaluate the presence and kinetics of metabolites derived from dermorphin. Five hours after its administration, the presence of dermorphin metabolites could be detected in both models by liquid chromatography coupled to highresolution mass spectrometry. RESULTS: Although the two models showed common results, marked differences were also observed in relation to the formed metabolites. Six putative metabolites, based on their exact masses of m/z 479.1915, m/z 501.1733, m/z 495.1657, m/z 223.1073, m/z 180.1017 and m/z 457.2085, are proposed to represent the metabolic pattern of dermorphin. The major metabolite generated from the administration of dermorphin in both models was YAFG-OH (m/z 457.2085), which is the N-terminal tetrapeptide previously identified from studies on rats. CONCLUSION: Its extensive characterization and commercial availability suggest that it could serve as a primary target analyte for the detection of dermorphin misuse. The metabolomics approach also allowed the assignment of other confirmatory metabolites.

A high throughput approach for determination of dermorphin in human urine using liquid chromatography-mass spectrometry for doping control purposes.

Dermorphin is a peptide with analgesic actions similar to morphine, but with greater effect and less potential to cause tolerance. The use of dermorphin has been documented in race horses, and its use in humans has already been reported. Considering the potential advantages from the use of dermorphin over morphine, a method to monitor it, and its main metabolite dermorphin (1-4) in humans becomes necessary for doping control. Here, we present two orthogonal methods for this purpose: a high-throughput liquid chromatography coupled to high-resolution mass spectrometry (HRMS) as an initial testing procedure and liquid chromatography-tandem mass spectrometry (MS/MS) in the selected reaction monitoring (SRM) acquisition mode for a confirmation procedure. For urine samples, pretreatment through a mixed-mode weak cation-exchange solid-phase extraction emerged as an effective approach to extract peptides from the biological sample. For the HRMS analysis, a full-MS scan acquisition mode was selected to detect the exact masses of dermorphin and dermorphin (1-4) at m/z 803.37226 and 457.20816, respectively. The SRM method used in the MS/MS confirmation protocol presented high specificity and sensitivity. The selected product ions for dermorphin were 602.2, 202.1 and 574.3 and for dermorphin (1-4) were 207.1, 223.1, and 235.1. Both methods were evaluated for specificity, repeatability, carryover, matrix effects, and recovery. No carryover and matrix effects were detected. The limit of detection for initial testing procedure and the limit of identification for confirmation procedure was 2.5 ng/ml. Also, specificity and robustness were acceptable for the application. Together, the developed methods proved to be efficient for the analysis of dermorphin and metabolite for human doping control purpose.