Pharmacokinetics of florfenicol in serum and seminal plasma in beef bulls

The objectives of this study were to compare the serum and seminal plasma pharmacokinetic profiles of florfenicol (FLO) and florfenicol amine (FLA) after the administration of FLO either by IM or SC routes in beef bulls. Four clinically healthy Hereford bulls underwent a comprehensive physical exam, including breeding soundness examination, CBC, and chemistry profile panel. Bulls were healthy and classified satisfactory potential breeders. In one group (n = 2), a single dose of FLO was administered SC in the middle of the neck at a dose of 40 mg/kg of body weight. In the second group (n = 2), a single dose was administered IM in the muscles of the neck at a dose of 20 mg/kg. Concentrations of FLO and FLA in serum and seminal plasma were determined by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Blood and semen samples were collected before the administration of FLO and at 12, 24, 36, 48, 72, 96, 120, 144, and 168 h after injection. The blood was collected from the coccygeal vessels, and semen was collected by electroejaculation. All samples were immediately refrigerated, processed within the first hour after collection, and finally stored at -80 °C. The mean level of total FLO in serum was higher when administered by the SC route (1,415.5 ng/mL) than by the IM route (752.4 ng/mL; P = 0.001). Differences were observed between the percentage of FLA in serum (1.8%; ranging from 1.3 to 2.9) and in seminal plasma (27.5%; ranging from 15.9 to 34.2; P = 0.0001). The mean level (±SD) of FLA was higher in seminal plasma compared to serum (467 ± 466 ng/mL and 18 ± 16 ng/mL, respectively; P = 0.001). The mean level of total FLO in seminal plasma was 1,454.8 ng/mL for the SC route and 1,872.9 ng/mL for the IM route without differences between the two routes (P = 0.51). Differences in the mean level of total FLO between serum and seminal plasma were detected (1,187 ± 2,069 ng/mL and 1,748 ± 1,906 ng/mL, respectively; P = 0.04). From the present investigation, it was concluded that FLO is a suitable antibiotic based on its pharmacokinetic attributes and may be employed for the treatment of bull genital infections when its use is indicated. To study the pharmacokinetics of FLO in seminal plasma, the analysis of FLA should be incorporated.

A Novel UHPLC-MS/MS Method for the Measurement of 25-Hydroxyvitamin D3 in Canine Serum and Its Application to Healthy Dogs

Several studies have shown the importance of vitamin D3 supplementation in small animals. In dogs, a low vitamin D3 status is associated not only with bone metabolism but also with different kinds of disorders, such as congestive heart failure, gastrointestinal diseases, chronic kidney diseases, and some types of cancer. However, it is crucial to maintain balance and monitor the introduction of this essential nutrient through the diet because over-supplementation can result in toxicity. Due to the clinical importance of assessing the vitamin D3 status in small animal patients, a quick, simple, and highly performing analytical method for its measurement is needed. In this study, we describe the development of a novel liquid chromatography-tandem mass spectrometry method for 25-hydroxyvitamin D3 quantification in canine serum. The approach was successfully validated following current European guidelines, proving excellent linearity (R2 always ≥0.996), accuracy (always within ±13%) and precision (always <10%). The application of the validated approach to samples collected from 40 healthy dogs made possible the definition of a reliable reference interval for 25-hydroxyvitamin D3, the main biomarker of vitamin D3. In addition, variations below 5% in the results obtained quantifying the same samples using a water-based calibration curve demonstrated that a surrogate matrix may be used without affecting data accuracy. Thanks to its simplicity, the proposed technique represents a useful tool for supporting clinical routine and investigating correlations between serum concentrations of this metabolite and multiple diseases. Additionally, it could enable the monitoring of supplementation in small animal patients in veterinary clinical practice.

Discovering the Protective Effects of Quercetin on Aflatoxin B1-Induced Toxicity in Bovine Foetal Hepatocyte-Derived Cells (BFH12)

Aflatoxin B1 (AFB1) induces lipid peroxidation and mortality in bovine foetal hepatocyte-derived cells (BFH12), with underlying transcriptional perturbations associated mainly with cancer, cellular damage, inflammation, bioactivation, and detoxification pathways. In this cell line, curcumin and resveratrol have proven to be effective in mitigating AFB1-induced toxicity. In this paper, we preliminarily assessed the potential anti-AFB1 activity of a natural polyphenol, quercetin (QUE), in BFH12 cells. To this end, we primarily measured QUE cytotoxicity using a WST-1 reagent. Then, we pre-treated the cells with QUE and exposed them to AFB1. The protective role of QUE was evaluated by measuring cytotoxicity, transcriptional changes (RNA-sequencing), lipid peroxidation (malondialdehyde production), and targeted post-transcriptional modifications (NQO1 and CYP3A enzymatic activity). The results demonstrated that QUE, like curcumin and resveratrol, reduced AFB1-induced cytotoxicity and lipid peroxidation and caused larger transcriptional variations than AFB1 alone. Most of the differentially expressed genes were involved in lipid homeostasis, inflammatory and immune processes, and carcinogenesis. As for enzymatic activities, QUE significantly reverted CYP3A variations induced by AFB1, but not those of NQO1. This study provides new knowledge about key molecular mechanisms involved in QUE-mediated protection against AFB1 toxicity and encourages in vivo studies to assess QUE's bioavailability and beneficial effects on aflatoxicosis.

Florfenicol and Florfenicol Amine Quantification in Bull Serum and Seminal Plasma by a Single Validated UHPLC-MS/MS Method

Florfenicol is a broad-spectrum antibiotic belonging to the amphenicols class that inhibits protein synthesis by binding to bacteria's ribosomal subunits. This drug is commonly used in veterinary medicine to treat bacterial infectious diseases in cattle, swine, poultry, and fish. The proposed method uses a quick protein precipitation with acetonitrile for the extraction of florfenicol and florfenicol amine in serum and seminal plasma, followed by analysis in UHPLC-MS/MS for their simultaneous quantification. A BEH C18 reversed-phase column was chosen for analyte separation, allowing to obtaining sharp and symmetrical peak shapes in a chromatographic run of just 3.5 min under programmed conditions. Two specific transitions were observed for each analyte, and florfenicol-d3 was used as the internal standard. The approach was fully validated in each matrix over ranges suitable for field concentrations of florfenicol and florfenicol amine, showing good linearity during each day of testing (R² always >0.99). Excellent accuracy and precision were demonstrated, for both analytes, by calculated bias always within ±15% and CV% always below 15% at all QC levels tested. The satisfactory outcomes obtained during recovery, matrix effect, and process efficiency investigations in serum and seminal plasma confirmed the strength of the method for the quantification of target compounds. To our knowledge, this is the first LC-MS/MS-validated approach for the quantification of florfenicol and florfenicol amine in serum and seminal plasma and was successfully applied for the determination of their concentration-time profiles in bulls. This paves the way to understanding the pharmacokinetics of this antibiotic and its active metabolite in bull's seminal plasma, which will enable the design of more appropriate treatment protocols.

Plant Essential Oils as a Tool in the Control of Bovine Mastitis: An Update

Bovine mastitis is a major concern for the dairy cattle community worldwide. Mastitis, subclinical or clinical, can be caused by contagious or environmental pathogens. Costs related to mastitis include direct and indirect losses, leading to global annual losses of USD 35 billion. The primary treatment of mastitis is represented by antibiotics, even if that results in the presence of residues in milk. The overuse and misuse of antibiotics in livestock is contributing to the development of antimicrobial resistance (AMR), resulting in a limited resolution of mastitis treatments, as well as a serious threat for public health. Novel alternatives, like the use of plant essential oils (EOs), are needed to replace antibiotic therapy when facing multidrug-resistant bacteria. This review aims to provide an updated overview of the in vitro and in vivo studies available on EOs and their main components as an antibacterial treatment against a variety of mastitis causing pathogens. There are many in vitro studies, but only several in vivo. Given the promising results of treatments with EOs, further clinical trials are needed.

The Use of Antibiotics and Antimicrobial Resistance in Veterinary Medicine, a Complex Phenomenon: A Narrative Review

As warned by Sir Alexander Fleming in his Nobel Prize address: “the use of antimicrobials can, and will, lead to resistance”. Antimicrobial resistance (AMR) has recently increased due to the overuse and misuse of antibiotics, and their use in animals (food-producing and companion) has also resulted in the selection and transmission of resistant bacteria. The epidemiology of resistance is complex, and factors other than the overall quantity of antibiotics consumed may influence it. Nowadays, AMR has a serious impact on society, both economically and in terms of healthcare. This narrative review aimed to provide a scenario of the state of the AMR phenomenon in veterinary medicine related to the use of antibiotics in different animal species; the impact that it can have on animals, as well as humans and the environment, was considered. Providing some particular instances, the authors tried to explain the vastness of the phenomenon of AMR in veterinary medicine due to many and diverse aspects that cannot always be controlled. The veterinarian is the main reference point here and has a high responsibility towards the human–animal–environment triad. Sharing such a burden with human medicine and cooperating together for the same purpose (fighting and containing AMR) represents an effective example of the application of the One Health approach.

Long-term prognosis in left ventricular non-compaction cardiomyopathy

Introduction

Left ventricular non compaction (LVNC) cardiomyopathy is an often underdiagnosed disease characterized by a thickened myocardium with a two-layered structure. Clinical presentations are very variable, ranging from an apparent lack of functional anomalies to heart failure, ventricular arrhythmias and, in some cases, even ischaemic stroke. Despite great improvements in diagnostic performance, there is still a wide lack of evidence regarding prognosis and management of affected patients.

Purpose

The aim of the present study was to investigate predictors of cardiovascular death or cardiovascular-related hospitalization in patients with LVNC over a long-term follow-up.

Methods

All consecutive patients with a definite diagnosis of LVNC admitted to the Cardiomyopathy Clinic of our institution from Jan 2015 to Dec 2020 were consecutively enrolled. Inclusion criteria were an age ≥18 years old and a diagnosis of LVNC made either by MRI or echocardiography. Exclusion criteria were a life expectancy ≤1 year and the inability to express informed consent for the study. All patients were follwed-up every six months. The primary endpoint was a composite of cardiovascular death and unplanned cardiovascular hospitalization.

Results

Twenty-one patients (14 male, age 40±17 years) meeting the inclusion criteria were prospectively enrolled and followed-up for a median of five years.

LVNC patients with a previous history of supraventricular tachycardia at the time of diagnosis are more likely to meet the primary composite endpoint during follow-up (60% vs. 18%; p=0.048; Figure 1). On the other hand, neither LVEF (measured either with echo or CMR) nor functional status were associated with a significantly increased risk of the composite endpoint (all p=NS). Other significant predictors of increased risk include history of OSAS (z2 = 4.158), active/previous smoking (z2 = 6.279), and ST-segment alterations (z2 = 4.158). NC/C, as measured by either echo or CMR, was not a predictor of cardiovascular events (HR 0.18; 95% CI 0.31–1.08; p=NS).

Conclusions

Our data show how, in patients with LVNC, supraventricular tachycardias are related to worse outcomes and their presence should prompt a closer follow-up in order to detect possible adverse events. ST-segment alterations, OSAS and smoking are also related to a poorer prognosis, but their relevance should be further assessed. Surprisingly, in our sample LVEF and NC/C ratio were not predictors of worse outcomes; the reason might be that in LVNC patients mortality and cardiovascular hospitalizations resemble complex genetic and molecular mechanisms that differentiate them from other cardiomyopathies, but the paucity of the population prevents us from making wider inferences.

Funding Acknowledgement

Type of funding sources: None.

Prognostic role of low QRS voltages in patients with cardiac amyloidosis

Introduction

Cardiac amyloidosis (CA) is an underdiagnosed and heterogeneous cardiac disease characterized by the extracellular deposition of misfolded proteins in the cardiac tissue. Clinical manifestations are heterogeneous leading to progressive heart failure, often complicated by arrhythmias and conduction system disease. Among several sign and symptoms that are suspicious for the disease, named “red flags”, disproportionally low QRS voltages on the ECG has been described.

Purpose

The aim of this prospective observational study is to evaluate potential prognostic features of QRS amplitude in AL e ATTR CA patients.

Methods

All consecutive patients admitted to the Cardiomyopathy Clinic of our institution have been enrolled after receiving CA diagnosis, according to the current guidelines. We included all patients ≥18 years with a diagnosis of CA and written informed consent. A complete assessment including a standard 12-lead electrocardiogram (ECG) and echocardiogram was performed at enrollment. Low QRS voltages (LQRSV) was defined as a QRS total amplitude of ≤5 mm in every limb leads and ≤10 mm in every precordial lead. LQRSV was tested as an independent predictor of death from all causes (primary endpoint), hospitalization from cardiovascular causes, ventricular and supraventricular arrhythmias.

Results

Sixty patients (46 males, 77±12 years old) were enrolled, of which 18 (30%) met the criteria for LQRSV. Patients with LQRSV presented more frequently with an history of ventricular arrhythmia (27.8% vs. 6.7%, p=0.04), a lower left ventricular diastolic volume (31±7 vs. 44±18 ml/m2; p=0.04), and higher retinol-binding-protein 4 (9.3±2.2 vs 3.2±1.5 mg/dl; p=0.02). No differences were seen in the primary outcome (46% vs. 50%; p=NS; Figure 1) or in the secondary ones (cardiovascular hospitalization 25% vs. 21%; ventricular arrhythmias 12% vs 4%; supraventricular arrhythmias 29% vs 19%; all p=NS) between the two groups during a median follow up of 1.1 year.

Conclusions

In the present cohort of CA patients LQRSV did not emerge as independent predictor of all-cause mortality at 1 year. Although LQRSV is a recognized diagnostic “red-flag” in the work-up of CA, its role as prognostic marker remains unclear. Further studies with a longer follow-up are needed to better define the prognostic role of LQRSV among CA patients.

Funding Acknowledgement

Type of funding sources: None.

Deepening the Whole Transcriptomics of Bovine Liver Cells Exposed to AFB1: A Spotlight on Toll-like Receptor 2

Aflatoxin B1 (AFB1) is a food contaminant metabolized mostly in the liver and leading to hepatic damage. Livestock species are differently susceptible to AFB1, but the underlying mechanisms of toxicity have not yet been fully investigated, especially in ruminants. Thus, the aim of the present study was to better characterize the molecular mechanism by which AFB1 exerts hepatotoxicity in cattle. The bovine fetal hepatocyte cell line (BFH12) was exposed for 48 h to three different AFB1 concentrations (0.9 µM, 1.8 µM and 3.6 µM). Whole-transcriptomic changes were measured by RNA-seq analysis, showing significant differences in the expression of genes mainly involved in inflammatory response, oxidative stress, drug metabolism, apoptosis and cancer. As a confirmatory step, post-translational investigations on genes of interest were implemented. Cell death associated with necrosis rather than apoptosis events was noted. As far as the toxicity mechanism is concerned, a molecular pathway linking inflammatory response and oxidative stress was postulated. Toll-Like Receptor 2 (TLR2) activation, consequent to AFB1 exposure, triggers an intracellular signaling cascade involving a kinase (p38β MAPK), which in turn allows the nuclear translocation of the activator protein-1 (AP-1) and NF-κB, finally leading to the release of pro-inflammatory cytokines. Furthermore, a p38β MAPK negative role in cytoprotective genes regulation was postulated. Overall, our investigations improved the actual knowledge on the molecular effects of this worldwide relevant natural toxin in cattle.

Pure and impure tachycardiomiopathy: key differences and long term prognosis

Funding Acknowledgements

Type of funding sources: None.

Introduction

Tachycardiomioathy (TCM) is a reversible cause of left ventricular (LV) dysfunction, secondary to both atrial and ventricular arrhythmias as well as high burden of ectopic beats. Almost 10% of all hospitalizations for acute heart failure (HF) meet the criteria for TCM. TCM is known to frequently recur and therefore cardiovascular related hospitalizations are often needed. While this is true in pure TCM, long term prognosis of impure TCM is still unknown.

Purpose

To compare long term prognosis of pure TCM to that of impure TCM in terms of survival rate, time free of recurrence and time free of hospitalizations.

Methods

Prospective, observational study enrolling all consecutive patients admitted for de novo acute heart failure, with a confirmed diagnosis of TCM, which was suspected in all patients admitted for heart failure (HF) with a LV ejection fraction &lt;50% and concomitant persistent atrial or ventricular arrhythmia, and confirmed after clinical and echocardiographic recovery. Pure tachycardiomiopathy was defined as an arrhythmia-induced LV dysfunction in an otherwise healthy heart. Impure tachycardiomiopathy was defined as an arrhythmia-mediated TCM, where the arrhythmia may exacerbate an underlying condition and facilitate LV dysfunction.

Results

Population included 123 patients with pure TCM and 40 patients with impure TCM. Patients with pure TCM were significantly younger (68±13 vs. 74±10 years; p=0.008) but a with similar risk factor profile and the same prevalence of male gender (63% vs 72%; p=ns). Similarly, echo characteristics did not significantly differ between the two groups, while pure TCM presented a higher HR at admission (124±28 vs. 106±28 bpm; p=0.001) but not at discharge (70±15 vs. 71±14 bpm; p=ns). Pure and impure TCM had similar EF on admission (33±9 vs. 34±7%; p=ns) and time to recovery after the acute event (4.9±0.6 vs. 4.4±1.4 months; p=ns). Pure TCM were more often treated in the acute phase with a rhythm control strategy (81% vs. 67%; p=0.001), mainly electric cardioversion followed by anti-arrhythmic drugs (80% vs. 46%; p&lt;0.001) and AF ablation (16% vs. 3%; p=0.025).

Kaplan Meier curves showed that pure TCM present a lower incidence of recurrence (26% vs. 50%; p=0.05; Figure 1) over a 40-month median follow-up. Cumulative incidences of death (24% vs. 30%; p=ns; Figure 2) and thromboembolism (3% vs. 3%; p=ns) were similar between the two groups over the same period. All-cause hospitalizations were similar between the two groups (62% vs. 67%; p=ns) with the impure TCMs experiencing more unplanned hospitalizations for HF recurrences.

Conclusions

While pure and impure TCM patients differs in terms of baseline characteristics, they present similar risk of death, thromboembolic events, and hospital admission during a long-term follow-up. Treatment strategy of pure TCM is more often rhythm-oriented and this could explain the lower incidence of HF recurrence.

Enantiospecific pharmacokinetics of intravenous dexmedetomidine in beagles

The goal of this study was to investigate the pharmacokinetic (PK) behaviour of dexmedetomidine in dogs administered as a pure enantiomer versus as part of a racemic mixture. Eight unmedicated intact purpose‐bread beagles were included. Two intravenous treatments of either medetomidine or dexmedetomidine were administered at 10‐ to 14‐day intervals. Atipamezole or saline solution was administered intramuscularly 45 min later. Venous blood samples were collected into EDTA collection tubes, and the quantification of dexmedetomidine and levomedetomidine was performed by chiral LC–MS/MS. All dogs appeared sedated after each treatment without complication. Plasma concentrations of levomedetomidine were measured only in the racemic group and were 51.4% (51.4%–56.1%) lower than dexmedetomidine. Non‐compartmental analysis (NCA) was performed for both drugs, while dexmedetomidine data were further described using a population pharmacokinetic approach. A standard two‐compartment mammillary model with linear elimination with combined additive and multiplicative error model for residual unexplained variability was established for dexmedetomidine. An exponential model was finally retained to describe inter‐individual variability on parameters of clearance (Cl₁) and central and peripheral volumes of distribution (V₁, V₂). No effect of occurrence, levomedetomidine or atipamezole could be observed on dexmedetomidine PK parameters. Dexmedetomidine did not undergo significantly different PK when administered alone or as part of the racemic mixture in otherwise unmedicated dogs.

A single LC-MS/MS validated method for tulathromycin quantification in plasma, seminal plasma and urine to be applied in a pharmacokinetic study in bull

Tulathromycin is a macrolide antibiotic generally used for the treatment of respiratory diseases in cattle and swine. This work proposes an improvement of a previously published LC‐MS/MS method for tulathromycin determination in pig serum, here validated in three different bull matrices: plasma, seminal plasma, and urine. The approach is based on a quick protein precipitation with acetonitrile, filtration, and sample dilution before injection, allowing to rapidly process large batches of samples. Analytes separation was obtained using a BEH C18 (50 × 2.1 mm, 1.7 μm) column, maintained at 40°C with a chromatographic run of 5 min. The method was fully validated over concentration ranges suitable for field levels of tulathromycin found in each matrix (0.01–1 μg/ml for plasma, 0.05–5 μg/ml for seminal plasma, and 0.1–10 μg/ml for urine), showing good linearity during each day of testing (R² always >0.99). Accuracy and precision were within ±15% at all QC concentrations in all the three matrices. Furthermore, the use of tulathromycine‐d7 as internal standard mitigated the potential impacts of matrix effect. The validated technique was successfully applied to samples collected during a pharmacokinetic study in bulls, allowing to monitor tulathromycin concentrations over time in the three matrices. To our knowledge, this is the first validated approach for LC‐MS/MS quantification of tulathromycin in seminal plasma and urine.

Validation of a single UHPLC-MS/MS approach for oxytetracycline determination in bull plasma, seminal plasma and urine

Oxytetracycline is a broad‐spectrum antibiotic, which inhibits protein synthesis and is generally used for the treatment of pneumonia, shipping fever, leptospirosis and wound infections in cattle and swine. The present work proposes a novel liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for oxytetracycline quantification in bull plasma, seminal plasma and urine, requiring limited sample treatment before analysis. Extraction with trichloroacetic acid followed by dilution of the supernatant in mobile phase proved to be effective in all three matrices, allowing to rapidly process large batches of samples. Sharp and symmetrical peak shape was obtained using a BEH C18 reversed‐phase column in a chromatographic run of just 3.5 min. The mass spectrometer operated in positive electrospray ionization mode and monitored specific transitions for oxytetracycline (461.1 → 425.8) and the internal standard demeclocycline (465.0 → 447.6). The method was validated over concentration ranges suitable for field concentrations of oxytetracycline found in each matrix, showing good linearity during each day of testing (R² always >0.99), as also confirmed by analysis of variance (ANOVA) and lack‐of‐fit tests. Excellent accuracy and precision were demonstrated by calculated bias always within ±15% and CV% below 10% at all quality control (QC) levels in the three matrices. Matrix effect and recovery were investigated for both analytes, which showed consistent and comparable behaviour in each matrix. To our knowledge, this is the first validated approach for mass spectrometric determination of oxytetracycline in seminal plasma and urine. The method was successfully applied to samples collected during a pharmacokinetic study in bulls, allowing to assess the oxytetracycline concentration–time profile in plasma, seminal plasma and urine.

Pharmacokinetics of tulathromycin on plasma and semen of beef bulls

The objective of this investigation was to evaluate the pharmacokinetic parameters of tulathromycin in plasma and semen of beef bulls after administering a single sc dose at two different sites in the neck. Four Simmental bulls with excellent temperament received a comprehensive physical exam that included breeding soundness examination. In addition, blood was collected and analyzed for CBC and chemical panel in order to rule out any subclinical liver or kidney disease. All bulls were diagnosed as healthy and satisfactory potential breeders. The mean plasma levels of tulathromycin for the two neck sites of sc administration were not different between posterior aspect of the ear where it attaches to the head (RP; regio parotidea; 77.9 ± 43.3 ng/mL; X ± SD) and to the middle of the neck (RC; regio collis lateralis; 73.7 ± 39.7 ng/mL; P = 0.84). The mean seminal plasma levels of tulathromycin after administration in the RP was 608 ± 374 ng/mL and for RC was 867 ± 599 ng/mL without differences between both sites (P = 0.29). The mean level of tulathromycin in plasma was 75.8 ± 40.2 ng/mL, which was lower than mean seminal plasma levels of 781 ± 482 ng/mL (P = 0.001). The plasma peak tulathromycin concentration (C_max) was 160 ± 27 ng/mL at 21 ± 6 h (T_max) post-administration. The seminal plasma C_max was 1539 ± 44.4 ng/mL at 33.00 ± 18.00 h (T_max) post-administration. The C_max between plasma and seminal plasma were different (P = 0.008) without any differences in T_max between plasma and seminal plasma (P = 0.35). The terminal half-life for plasma tulathromycin (81.4 ± 27.6 h) showed a tendency to be shorter than in seminal plasma (114.7 ± 21.7; P = 0.10). The plasma area under the curve concentration time from the first to the last sample (AUC_0-last) was 15,440 ± 1717 ng/mL/h, which was significatively smaller compared with 171,071 ± 58,556 ng/mL/h for seminal plasma AUC_0-last (P = 0.01). The plasma means residence time from the first to the last sample (MRT_0-last) was 89.3 ± 5.1 h and it was shorter than for seminal plasma of 96.6 ± 5.0 h (P = 0.05). From the present investigation, it was concluded that tulathromycin is a suitable antibiotic based in its pharmacokinetic properties that could be used for treatment of bull genital infections when its application is indicated.

Comparison of methods to monitor dogs with hypercortisolism treated with trilostane

Background

The use of adrenocorticotropic hormone stimulation test as method to monitor efficacy of trilostane treatment of hypercortisolism (HC) in dogs has been questioned.

Objectives

To evaluate and compare 12 methods with which to monitor efficacy of trilostane treatment in dogs with HC.

Animals

Forty‐five client‐owned dogs with HC treated with trilostane q12h.

Methods

Prospective cross‐sectional observational study. The dogs were categorized as well‐controlled, undercontrolled, and unwell through a clinical score obtained from an owner questionnaire. The ability to correctly identify trilostane‐treatment control of dogs with HC with the following variables was evaluated: before trilostane serum cortisol (prepill), before‐ACTH serum cortisol, post‐ACTH serum cortisol, plasma endogenous ACTH concentrations, prepill/eACTH ratio, serum haptoglobin (Hp) concentration, serum alanine aminotransferase (ALT), gamma‐glutamyl transferase (γGT) and alkaline phosphatase activity, urine specific gravity, and urinary cortisol : creatinine ratio.

Results

Ninety‐four re‐evaluations of 44 dogs were included; 5 re‐evaluations of 5 unwell dogs were excluded. Haptoglobin was significantly associated with the clinical score (P < .001) and in the receiver operating characteristic analysis, Hp cutoff of 151 mg/dL correctly identified 90.0% of well‐controlled dogs (specificity) and 65.6% of undercontrolled dogs (sensitivity). Alanine aminotransferase (P = .01) and γGT (P = .009) were significantly higher in undercontrolled dogs. Cutoff of ALT and γGT greater than or equal to 86 U/L and 5.8 U/L, respectively, were significantly associated with poor control of HC by trilostane.

Conclusions and Clinical Importance

Of all the 12 variables, Hp, and to a lesser degree ALT and γGT, could be considered additional tools to the clinical picture to identify well‐controlled and undercontrolled trilostane‐treated dogs.

Long-term prognosis of tachycardiomyopathy without underlying heart disease

Background

Tachycardiomyopathy (TCM) is a reversible cause of left ventricular dysfunction, secondary to rapid and/or asynchronous, irregular myocardial contraction. Two categories of the disease have been described: arrhythmia-induced TCM (pure TCM), where the arrhythmia is the sole reason for the dysfunction, and arrhythmia-mediated TCM (impure TCM), where the arrhythmia can exacerbate or worsen heart failure (HF) or an underlying heart disease. Pure TCM has already been described as affecting almost 1 out of 10 patients admitted for acute HF-like symptoms. On the other side, acute HF leads to a chronic irreversible condition which tends to worsen over time and is burdened by a high rate of complications.

Purpose

The aim of our study was to compare pure TCM and de novo acute HF patients (including all forms of structural heart disease) in terms of mortality and cardiovascular (CV)-related hospitalizations.

Methods

Prospective, observational study enrolling all consecutive patients with a confirmed diagnosis of TCM and all patients admitted for de novo acute HF. The TCM diagnosis was suspected in all patients admitted for HF-related symptoms, an ejection fraction &lt;50% with concomitant persistent atrial or ventricular arrhythmia, and confirmed after clinical and echocardiographic recovery. Acute HF diagnosis was made in all patients with an ejection fraction &lt;50%, new HF-like symptoms, diagnosis of structural heart disease and no evidence of clinical or echocardiographic recovery. For each patient, all-cause death and CV-related hospitalizations were recorded. Propensity score matching was used in order to compare the two populations through sensitivity analysis.

Results

One-hundred-and-ten patients with TCM (61.8% males, 68±13 years old) were propensity matched with a control population of patients with HF and structural heart disease (76.6% males, 71±15 years old, 75% ischemic heart disease). After a median follow-up of 5.1 years (1st-3rd quartile 2.6–7.0 years) TCM patients showed an overall higher estimate of survival when compared to HF patients (78% vs. 58%; p=0.031; figure 1A) but a lower estimate of time free from CV-related hospitalization (31% vs. 57%, p=0.014; figure 1B). TCM patients got most often readmitted for AF-related elective procedures (60.8% of all hospitalizations), TCM recurrence (13.7%) and elective coronary angiography (5.9%). On the other hand, HF patients got readmitted for HF worsening (40.9%), cardiac or vascular surgery (22.7%) and elective coronary angiography (9.1%). Propensity-score matched analysis confirmed the results for all-cause death (81% vs. 49%; p=0.006) and CV-related hospitalizations (29% vs. 54%; p=0.007).

Conclusions

TCM is associated with a better survival when compared to de novo acute HF, even after propensity score adjustment. On the other hand, patients with TCM got readmitted more frequently, requiring more often elective procedures in order to control the triggering arrhythmia.

Funding Acknowledgement

Type of funding sources: None.

A critical point in chiral chromatography-mass spectrometry analysis of ketamine metabolites

Ketamine is a widely used dissociative drug, whose quantification in plasma and urine can be of pharmacological, toxicological, and clinical interest. Although tandem mass spectrometry allows the reliable determination of ketamine and its metabolites in biological matrices, the structural similarity between norketamine (main active metabolite) and dehydronorketamine (a less relevant metabolite) can represent a critical aspect. These compounds differ exclusively in two hydrogen atoms, but the consequent two‐unit difference in their mass/charge ratio is partially nullified by the isotopic abundance of the chlorine atom present in their structure. This, along with their similar fragmentation pattern, can result in the incorrect identification of the enantiomers of these ketamine metabolites even with triple quadrupole instruments, if shared transitions are monitored after chiral chromatography. The key to prevent norketamine overestimation is therefore observing analyte‐specific MS/MS transitions. Here, we describe in detail how we investigated this issue, during the development of an analytical method for ketamine and norketamine enantiomer determination in plasma.

The accuracy and precision of insulin administration using human and veterinary pen-injectors and syringes for administration of insulin

BACKGROUND

Many diabetic dogs and cats require small doses of insulin that must be administered accurately.

OBJECTIVES

To compare the accuracy and precision of insulin syringes and pen-injectors.

ANIMALS

None.

METHODS

To determine how accurately and precisely insulin doses are delivered, 0.5, 1, 2, 4, 8, and 16 U doses were dispensed 25 times from 5 SoloSTARs, 5 FlexPens, 5 KwikPens, 5 JuniorSTARs, 5 VetPens 0.5-8 U, 5 VetPens 1-16 U, and by 5 veterinarians using 30 U/0.3 mL and 40 U/mL insulin syringes. Each dose was weighed, using a precision balance, and the intended and delivered doses were compared.

RESULTS

All pen-injectors delivered less insulin than the intended dose, underdosage being inversely proportional to insulin dose. The differences between the intended and the delivered dose were not significant using JuniorSTAR and VetPen 0.5-8 U at insulin doses of 0.5, 1, 2, and 4 U, using the 30 U/0.3 mL insulin syringe at the 4 U dose and using the 40 U/mL insulin syringe at the 4, 8, and 16 U doses. With all the devices, precision increased with increasing doses of insulin. The coefficient of variation was <8% for all 6 pen-injectors. Conversely, using 30 U/0.3 mL and 40 U/mL syringes at an insulin dosage of 0.5 U the coefficients of variation were 12.08% and 9.39%, respectively.

CONCLUSIONS AND CLINICAL IMPORTANCE

JuniorSTAR and VetPen 0.5-8 U were more accurate than the other devices when delivering ≤2 U doses, while the delivery of 8 and 16 U doses was more accurate using 40 U/mL syringes.

Clinical Randomized Comparison of Medetomidine and Xylazine for Isoflurane Balanced Anesthesia in Horses

Introduction: To assess drug plasma levels, preanesthetic sedation, cardiopulmonary effects during anesthesia and recovery in horses anesthetized with isoflurane combined with medetomidine or xylazine.

Study design: Prospective blinded randomized clinical study.

Animals: Sixty horses undergoing elective surgery.

Methods: Thirty minutes after administration of antibiotics, flunixine meglumine or phenylbutazone and acepromazine horses received medetomidine 7 μg kg⁻¹ (group MED) or xylazine 1.1 mg kg⁻¹ (group XYL) slowly intravenously (IV) and sedation was assessed 3 min later. Anesthesia was induced with ketamine/diazepam and maintained with isoflurane in oxygen/air and medetomidine 3.5 μg kg⁻¹ h⁻¹ or xylazine 0.69 mg kg⁻¹ h⁻¹. Ringer's acetate 10 mL kg⁻¹ h⁻¹ and dobutamine were administered to maintain normotension. All horses were mechanically ventilated to maintain end-tidal carbon dioxide pressures at 45 ± 5 mmHg (5.3–6.7 kPa). Heart rate (HR), invasive arterial blood pressures, inspired and expired gas compositions, pH, arterial blood gases, electrolytes, lactate and glucose were measured. For recovery all horses received intramuscular morphine 0.1 mg kg⁻¹ and medetomidine 2 μg kg⁻¹ or xylazine 0.3 mg kg⁻¹ IV. Recovery was timed and scored using three different scoring systems. Plasma samples to measure medetomidine and xylazine concentrations were collected at predetermined timepoints. Repeatedly measured parameters were analyzed using a two-way repeated-measures analysis of variance for differences between groups and over time; p < 0.05 was considered statistically significant.

Results: Mean arterial blood pressures (MAP) stayed within normal ranges but were higher (p = 0.011) in group XYL despite significant lower dobutamine doses (p = 0.0003). Other measured parameters were within clinically acceptable ranges. Plasma levels were at steady state during anesthesia (MED 2.194 ± 0.073; XYL 708 ± 18.791 ng mL⁻¹). During recovery lateral recumbency (MED 42.7 ± 2.51; XYL 34.3 ± 2.63 min; p = 0.027) and time to standing (MED 62.0 ± 2.86; XYL 48.8 ± 3.01 min; p = 0.002) were significantly shorter in group XYL compared to group MED. Recovery scores did not differ significantly between groups.

Conclusion and Clinical Relevance: In horses anesthetized with isoflurane and medetomidine or xylazine, xylazine maintained higher MAP, reduced the dobutamine consumption and recovery time, whilst overall recovery quality was unaffected.

A quick approach for medetomidine enantiomer determination in dog plasma by chiral liquid chromatography-tandem mass spectrometry and application to a pharmacokinetic study

In the present study, a rapid, sensitive and high-throughput liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of medetomidine enantiomers in dog plasma was developed and validated. The separation and individual quantification of chiral compounds can be a tricky task in LC. This is particularly true when target analytes have a relatively small mass, as is the case with medetomidine, a potent and highly specific α2-adrenoceptor agonist widely used in both human and veterinary medicine. The proposed approach is based on a quick liquid-liquid extraction with ethyl acetate and filtration prior to injection. The optimized mobile phase composition allowed to perfectly separate the two enantiomers of medetomidine in a short chromatographic run time, using a cellulose tris(4-methylbenzoate)-based chiral column. A lower limit of quantification of 0.1 ng/mL was reached for both analytes thanks to the high sensitivity and selectivity of MS/MS and the use of racemic medetomidine-d3 as internal standard prevented potential matrix effect. Linearity was satisfying (R²  > 0.99) over the range 0.1-25 ng/mL, as well as within- and between-session accuracy and precision, both always <15%. This method was also applied with success to a series of samples from a pharmacokinetic (PK) study aimed at comparing dex- and levomedetomidine behaviour after administration of the racemic mixture in dogs. The simple extraction procedure, which allows reduced solvent and time consumption without compromising analytical performances, makes this technique a useful tool for this kind of applications even when small animals are involved, due to the small amount of sample required.

Curcumin Mitigates AFB1-Induced Hepatic Toxicity by Triggering Cattle Antioxidant and Anti-inflammatory Pathways: A Whole Transcriptomic In Vitro Study

Aflatoxin B1 (AFB1) toxicity in livestock and human beings is a major economic and health concern. Natural polyphenolic substances with antioxidant properties have proven to be effective in ameliorating AFB1-induced toxicity. Here we assessed the potential anti-AFB1 activity of curcumin (pure curcumin, C, and curcumin from Curcuma longa, CL) in a bovine fetal hepatocyte-derived cell line (BFH12). First, we measured viability of cells exposed to AFB1 in presence or absence of curcumin treatment. Then, we explored all the transcriptional changes occurring in AFB1-exposed cells cotreated with curcumin. Results demonstrated that curcumin is effective in reducing AFB1-induced toxicity, decreasing cells mortality by approximately 30%. C and CL induced similar transcriptional changes in BFH12 exposed to AFB1, yet C treatment resulted in a larger number of significant genes compared to CL. The mitigating effects of curcuminoids towards AFB1 toxicity were mainly related to molecular pathways associated with antioxidant and anti-inflammatory response, cancer, and drug metabolism. Investigating mRNA changes induced by curcumin in cattle BFH12 cells exposed to AFB1 will help us to better characterize possible tools to reduce its consequences in this susceptible and economically important food-producing species.

P431Flecainide or propafenone oral bolus to facilitate electrical cardioversion of persistent atrial fibrillation

Background

 electrical cardioversion (ECV) of atrial fibrillation (AF) is a pivotal component of the rhythm control approach. Although ECV is safe and effective in the majority of patients, approximately one patient out of ten experiences an early or very early recurrence. In order to improve ECV’s success rate, oral or intravenous amiodarone pre-treatment is commonly prescribed and followed by a second ECV attempt. However, due to the long time needed to achieve therapeutic levels and the high risk of phlebitis, faster and safer strategies to facilitate ECV are highly needed.

Purpose

 to evaluate whether the administration of a flecainide or propafenone oral bolus followed by ECV would prove effective and safe in facilitating conversion to sinus rhythm in patients with persistent AF and a prior ECV failure.

Methods

we conducted a prospective, open-label, single center observational study. The case group was formed by patients with persistent AF and a prior ECV failure receiving flecainide or propafenone oral bolus (at the same doses used for the "pill-in-the-pocket" approach) followed by a second ECV attempt 3 hours after drug ingestion. For comparison, we selected patients with a prior ECV failure that underwent amiodarone-facilitated ECV. Before ECV, amiodarone was either administered orally for at least 1 month or intravenously for 24 hours. The primary outcome was conversion to sinus rhythm, defined as sinus rhythm persisting for at least 12 hours after ECV.

Results

patient’s characteristics were well balanced in the 3 groups, apart from slightly lower left ventricular ejection fraction values in the amiodarone groups. The day after ECV failure, 29 patients received oral flecainide at a 200 mg (n = 15) or at a 300 mg (n = 14) dose and one patient received oral propafenone at a 600 mg dose before undergoing a second ECV attempt. In nine patients, amiodarone was given intravenously for 24 hours. Amiodarone was prescribed orally to 22 patients for a median of seven weeks at an average daily dose of 241.4 mg. In the flecainide/propafenone group, one patient converted to sinus rhythm one hour after drug ingestion; among the other 29 subjects, the second ECV was effective in 23 (cumulative effectiveness: 80.0%). In the intravenous amiodarone group, 2 patients converted to sinus rhythm during drug infusion; among the other 7, the second ECV proved effective in 4 (cumulative effectiveness: 66.7%). In the oral amiodarone group, ECV was successful in 17 patients (77.3%). When comparing the three groups, the primary outcome occurred in a similar proportion of patients (Chi-squared test: p = 0.34; Fisher’s exact test: p = 0.24). Serious adverse events were not reported.

Conclusions

flecainide or propafenone oral bolus quickly facilitated conversion to sinus rhythm in the vast majority of patients with persistent AF and a prior ECV failure with a low inherent risk of adverse events. Flecainide effectiveness proved similar to intravenous or oral amiodarone.

Modulation of aflatoxin B1 cytotoxicity and aflatoxin M1 synthesis by natural antioxidants in a bovine mammary epithelial cell line

Aflatoxin (AF) B1, a widespread food and feed contaminant, is bioactivated by drug metabolizing enzymes (DME) to cytotoxic and carcinogenic metabolites like AFB1-epoxide and AFM1, a dairy milk contaminant. A number of natural antioxidants have been reported to afford a certain degree of protection against AFB1 (cyto)toxicity. As the mammary gland potentially participates in the generation of AFB1 metabolites, we evaluated the role of selected natural antioxidants (i.e. curcumin, quercetin and resveratrol) in the modulation of AFB1 toxicity and metabolism using a bovine mammary epithelial cell line (BME-UV1). Quercetin and, to a lesser extent, resveratrol and curcumin from Curcuma longa (all at 5 μM) significantly counteracted the AFB1-mediated impairment of cell viability (concentration range: 96-750 nM). Moreover, quercetin was able to significantly reduce the synthesis of AFM1. The quantitative PCR analysis on genes encoding for DME (phase I and II) and antioxidant enzymes showed that AFB1 caused an overall downregulation of the detoxifying systems, and mainly of GSTA1, which mediates the GSH conjugation of the AFB1-epoxide. The negative modulation of GSTA1 was efficiently reversed in the presence of quercetin, which significantly increased GSH levels as well. It is suggested that quercetin exerts its beneficial effects by depressing the bio-transformation of AFB1 and counterbalancing its pro-oxidant effects.

A quick and simple method for the determination of ivermectin in dog plasma by LC-MS/MS

Ivermectin is an endectocide belonging to the macrocyclic lactone class, commonly used in dogs as a heartworm preventative and for the treatment of several external and internal parasite infections. Among the analytical methods for ivermectin determination in plasma available in literature, many require a laborious clean-up step on SPE cartridge, and use fluorescence detection instead of the more reliable mass spectrometry. In the context of a project aimed at its pharmacokinetic evaluation in this species, a liquid chromatography-tandem mass spectrometry method for the determination of ivermectin in dog plasma was developed and validated, using blank plasma provided by a local canine blood transfusion service. Samples underwent a quick liquid-liquid extraction before analysis in the LC–MS/MS system, operating in selected reaction monitoring (SRM) mode. The method provided satisfactory linearity (R² >0.99), accuracy (bias <3%) and precision (CV <10%) over the 0.5–20.0 ng/mL range.

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This is to our knowledge the first validated LC–MS/MS method for ivermectin determination in dog plasma.

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Sample preparation is simple, rapid and inexpensive, without compromising sensitivity.

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The modest amount of plasma required makes the proposed technique suitable for pharmacokinetic studies also in small dogs.

Evaluation of methadone concentrations in bitches and in umbilical cords after epidural or systemic administration for caesarean section: A randomized trial

OBJECTIVE

To measure plasma methadone concentrations in bitches and the umbilical cords of their puppies after systemic or epidural administration.

STUDY DESIGN

Prospective, randomized, clinical study.

ANIMALS

A total of 27 healthy pregnant female dogs undergoing caesarean section, 4.3 ± 2.3 years of age and weighing 19.9 ± 13.2 kg.

METHODS

The dogs were randomly divided into three groups: 1) intramuscular methadone (0.3 mg kg^-1) (group MET; n = 9); 2) epidural methadone (0.1 mg kg^-1) (group METEPI; n = 9); and 3) epidural lidocaine (4.4 mg kg^-1) [group CON (control group); n = 9]. Ten minutes before induction, methadone was administered intramuscularly to the group MET dogs. Anaesthesia was induced with propofol and maintained with isoflurane. Cardiovascular and respiratory parameters were monitored throughout the anaesthesia. After induction, epidural anaesthesia was administered to dogs in groups METEPI and CON. Before any treatment (T0) and, as soon as the last foetus was removed from the uterus (T1), venous blood samples were collected from each dog into heparinized tubes; the umbilical cords were collected and stored at -80 °C until pharmacological analysis was carried out. The samples were analysed using ultra performance liquid chromatography.

RESULTS

The cardiorespiratory parameters of the bitches and of the puppies at birth, and the Apgar scores did not differ significantly between groups. At T1 both the median maternal methadone plasma concentration and the median methadone umbilical cord concentration were higher in group MET compared to group METEPI (p = 0.0018 and p = 0.004, respectively). The maternal plasma concentration was higher than the concentration in the umbilical cords (p = 0.05) in group METEPI but not in group MET (p = 0.25).

CONCLUSIONS AND CLINICAL RELEVANCE

Epidural methadone (0.1 mg kg^-1) administered to bitches undergoing caesarean section is associated with lower umbilical cord methadone concentrations as compared with intramuscularly administered methadone at higher dosages (0.3 mg kg^-1).

Tolerability and pharmacokinetics of two antimony products after subcutaneous administration in dogs

INTRODUCTION

Pentavalent antimony is the first choice drug for leishmaniasis in dog. Leishmaniasis has a complex pathogenesis and it manifests various clinical signs, some of which are often similar to those associated with the toxicity induced by antimonial treatment. Among the reasons for this toxicity, also a general problem of drug's quality has been reported.

METHODOLOGY

The general and local tolerability of two commercially available meglumine antimoniate based veterinary products was evaluated in 12 healthy dogs, 6 receiving Antimania (Fatro, Italy) and 6 receiving Glucantime (Merial, Spain), following repeated subcutaneous administrations of therapeutic doses for 14 days.

RESULTS

Individual and mean values of haematological and biochemical parameters in both groups remained in the physiological range, with no considerable differences within the two groups. The general tolerability of the drugs was also supported by clinical observations and physical examination of the dogs throughout the whole study period. Only slight local reactions at the injection sites, that spontaneously disappeared, were observed for both products starting from 12-84 hours after the administration. The pharmacokinetic parameters indicated no antimony accumulation.

CONCLUSIONS

These results suggest that meglumine antimoniate administered at the recommended dosage regimen is well tolerated by healthy dogs, and that there is no significant difference between the two tested products.

Survey on antimicrobial prescribing patterns in small animal veterinary practice in Emilia Romagna, Italy

This investigation provides for the first time a general view of the prescribing patterns of antimicrobials in small animal practice in Emilia Romagna, Italy. In the context of a project on antimicrobial resistance managed by the Regional Veterinary Service, veterinary clinicians were invited to voluntarily complete an online questionnaire. This was designed to gather information on antimicrobial prescribing practices and biosecurity measures and to understand the perception of the issue specific to this region of Italy. In total, 266 questionnaires correctly completed were collected. Although clinicians seemed to follow different approaches when using antimicrobials, the data analysis revealed a general awareness on resistance. Penicillins were the most commonly prescribed class, followed by (fluoro)quinolones and cephalosporins. Among those who use laboratory testing more or less frequently (microbiological analysis and susceptibility testing) to support their prescribing habits, only 7 per cent make a habit of always waiting for the results before starting the treatment. Seventy-eight per cent of the respondents declared the use of antimicrobials licensed for human beings. Biosecurity measures were carefully taken into account by the majority of the veterinarians. The results identified the antimicrobial classes that are commonly prescribed and highlighted that perioperative hygiene measures and the use of laboratory diagnosis are critical aspects that need to be emphasised in drawing up guidelines on the prudent use of these drugs in pets.

Assessment of Perfluorooctane Sulfonate and Perfluorooctanoic Acid Exposure Through Fish Consumption in Italy

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are pollutants of anthropic origin with possible side effects on human health. Diet, and in particular fish and seafood, is considered the major intake pathway for humans. The present study investigated the levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) contamination in twenty-five samples of fresh fillet of five widely consumed fish species purchased from large retailers in Italy, to be used for an estimation of the Italian population exposure to these contaminants. PFOS and PFOA were found in all samples, at concentrations up to 1896 (mean=627 ng/kg) and 487 ng/kg (mean = 75 ng/kg), respectively, confirming the role of fish as high contributor to human exposure. However, a remarkable inter-species variability was observed, and multiple factors were suggested as potentially responsible for such differences, suggesting that the preferential consumption of certain species could likely increase the intake, and thus the exposure. The exposure estimates for both average and high fish consumers resulted far below the tolerable daily intakes for PFOS and PFOA in all age groups, confirming the outcomes of EFSA’s scientific report. In particular, the calculated total dietary exposure for the 95^th percentile consumers belonging to the toddler age class, the most exposed group, resulted equal to 9.72 ng/kg body weight (BW)/day for PFOS and 8.39 ng/kg BW/day for PFOA.

An LC-MS/MS method for the determination of budesonide and 16α-hydroxyprednisolone in dog plasma

Although budesonide is frequently used in veterinary medicine for the treatment of canine respiratory and bowel inflammatory diseases, knowledge is lacking regarding its kinetics in this species. We developed and validated a liquid chromatography–tandem mass spectrometry method for the determination of budesonide and its metabolite 16α-hydroxyprednisolone in dog plasma. The analytes were extracted by solid phase extraction and analysis was performed by high performance liquid chromatography–tandem mass spectrometry, with positive electrospray ionization.•

This method allows budesonide and one of its main metabolites to be simultaneously quantified in dog plasma at fairly low concentrations.

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The proposed protocol is very easy and fast to execute, without compromising analytical performances.

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A small amount (0.5 mL) of plasma is required, making this approach suitable for pharmacokinetic studies also in small sized dogs.

Determination of Vitamin B12 in Dairy Products by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

Vitamin B₁₂ is a water-soluble molecule composed of a tetrapyrrolic complex with a cobalt atom at its centre. It is an essential regulatory element, synthesized only by bacteria; for this reason it is present only in food of animal origin and the daily requirement for humans is about 1 to 2 mg. Since milk and dairy products provide a significant dietary cobalamin intake, an ultra performance liquid chromatographytandem mass spectrometry method was applied to samples collected at different stages along the process of cheese making in order to evaluate the distribution of this molecule. In particular, samples of milk, rennet, whey, ricotta cheese, curd, mozzarella cheese and caciotta cheese were analysed. Results showed a level of vitamin B₁₂ about 10 times higher in whey and ricotta cheese with respect to the milk they are derived from. These data would confirm the tendency of cobalamine to concentrate in the proteic fractions along the cheese production process.

Short communication: Monitoring the presence of perfluoroalkyl substances in Italian cow milk

Perfluoroalkyl substances (PFAS) are fully fluorinated compounds widely used during the last 60 yr in the production of multiple industrial and consumer applications, such as food packaging, nonstick cookware, cleaning agents, and many more. These emerging contaminants have recently become of concern for human health because of their potential negative effects. The risk of exposure to PFAS for humans is mainly related to diet, and the increasing interest in food safety has led the European Commission to call Member States to monitor these contaminants in food matrices. The purpose of the present work was to perform the first monitoring on the presence of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), the 2 main and most widely investigated molecules of this family, in cow milk commercially available in Italy. We used an analytical protocol consisting of liquid-liquid extraction followed by 2 purification steps through solid-phase extraction cartridges and injection on an ultra-performance liquid chromatography-tandem mass spectroscopy system. The analysis of 67 samples of different types of cow milk from Italy demonstrated that contamination by PFOS was often present, although at relatively low concentrations (up to 97 ng/L), whereas PFOA was rarely found. On the basis of these results and data reported in the literature on this matrix, milk does not seem to be a major source of PFAS compared with other food categories such as fish and seafood. However, variability among different types of milk must be taken into account, and surveys of milk-derived products would be helpful to better define the risk for consumers.

A quick LC-MS-MS method for the determination of flunixin in bovine muscle

A simple, fast and cost-effective liquid chromatographic/tandem mass spectrometry (LC-MS-MS) method for the quantitative determination of flunixin (FLU) in bovine muscle was developed and validated. The sample preparation procedure involved an extraction with acetonitrile, followed by evaporation and reconstitution. Chromatographic separation was achieved on a reverse-phase column under programmed conditions. FLU detection was performed with positive electrospray ionization in selected reaction monitoringmode, monitoring one precursor and two products ions. For quantification purposes, FLU-d3 was used as an internal standard. The matrix effect on the analysis of FLU in bovine muscle was evaluated by comparison between calibration curves prepared with standard solution and in blank matrix extracts. The equivalent responses obtained confirmed the absence of signal suppression or/and enhancement. The method was extensively validated according to the parameters requested by European Commission Decision 2002/657/EC in terms of specificity, limit of detection, linearity, trueness, precision, decision limit (CCα) and detection capability (CCβ). FLU stability was also investigated in matrix and in sample extracts at different times and storage conditions.

Technical note: development and validation of a method using ultra performance liquid chromatography coupled with tandem mass spectrometry for determination of vitamin B12 concentrations in milk and dairy products

A method using ultra performance liquid chromatography coupled with tandem mass spectrometry was developed to measure cobalamins in naturally enriched raw milk and to evaluate their fate during thermal treatments and along the process of cheese making. After addition of methotrexate as internal standard, samples were submitted to heat treatment in the presence of cyanide, which converts all the less-stable cobalamins into cyanocobalamin; then, purification was performed by a solid-phase extraction step. Reverse-phase ultra performance liquid chromatography separation coupled with tandem mass spectrometry provided a fast and reliable determination. Mass spectrometric analysis was carried out in multiple reaction monitoring mode. The monitored transitions were m/z 678.36 → 147.10 and 678.36 → 359.30 for vitamin B12 and m/z 455.22 → 175.13 and 455.22 → 308.22 for methotrexate (internal standard). The limit of quantification was 2 ng/g. The method showed good linearity from 2 to 20 ng/g (R(2) ≥ 0.98) and intra- and interday precisions were always less than 19%.

Perfluoroalkyl substances in human milk: a first survey in Italy

Due to their widespread diffusion, perfluoroalkyl substances (PFASs) have been frequently found in the environment and in several animal species. It has been demonstrated that they can easily reach also humans, mainly through diet. Being lactation a major route of elimination of these contaminants, their occurrence in human milk is of particular interest, especially considering that it generally represents the unique food source for newborns. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), the two most important compounds of this family, have been frequently found in human milk at variable concentrations, but still limited data are available. The present study, the first conducted in Italy capable to detect these pollutants at ultra-trace levels by UPLC-MS/MS, confirmed the role of lactation as a relevant source of exposure for breastfed children. The measured concentrations ranged between 15 and 288 ng/L for PFOS and between 24 and 241 ng/L for PFOA. Moreover, mean concentrations and frequencies of both analytes resulted higher in milk samples provided by primiparous women, suggesting that the risk of intake might be higher for first-borns. Finally, comparing these results with previous data, PFOS gradual decrease over time since year 2000 was confirmed.

Development of an analytical strategy based on liquid chromatography-high resolution mass spectrometry for measuring perfluorinated compounds in human breast milk: application to the generation of preliminary data regarding perinatal exposure in France

Perfluorinated compounds (PFCs) are man-made chemicals for which endocrine disrupting properties and related possible side effects on human health have been reported, particularly in the case of an exposure during the early stages of development, (notably the perinatal period). Existing analytical methods dedicated to PFCs monitoring in food and/or human fluids are currently based on liquid chromatography coupled to tandem mass spectrometry, and were recently demonstrated to present some limitations in terms of sensitivity and/or specificity. An alternative strategy dedicated to the analysis of fourteen PFCs in human breast milk was proposed, based on an effective sample preparation followed by a liquid chromatography coupled to high resolution mass spectrometry measurement (LC-HRMS). This methodology confirmed the high interest for HRMS after negative ionization for such halogenated substances, and finally permitted to reach detection limits around the pg mL(-1) range with an outstanding signal specificity compared to LC-MS/MS. The proposed method was applied to a first set of 30 breast milk samples from French women. The main PFCs detected in all these samples were PFOS and PFOA with respective median values of 74 (range from 24 to 171) and 57 (range from 18 to 102) pg mL(-1), respectively. These exposure data appeared in the same range as other reported values for European countries.