1,720,974 research outputs found
Endocrine evaluation after an intra-articular therapeutic dosage of dexamethasone in horses
No full textThis study investigated whether a single intra-articular administration (IA) of dexamethasone (DEX) in horses at therapeutic dosage could exert a systemic effect by influencing the hypothalamic-pituitary-adrenal axis activity as a consequence of (limited) absorption and systemic distribution. The results indicated that DEX was detectable in urine collected 12-48 h after IA administration and that injection was accompanied by a reduced urine excretion of cortisol, 6β-hydroxycortisol (6βOHF) and two other metabolites of cortisol lasting up to 48 h post-DEX administration. The systemic effects in horses treated with DEX by IA route are similar to those that typically occur with short-term treatment including the reduction in urinary cortisol concentration
Investigation on possible transformations of cortisol, cortisone and cortisol glucuronide in bovine faecal matter using liquid chromatography-mass spectrometry
No full textGiven the close resemblance of the ring A structure of prednisolone and prednisone on the one hand,and of androstadienedione on the other, the transformation of cortisol and cortisone into prednisolone and prednisone in cattle faeces was evaluated. A simple method that does not involve extraction but only the 1:100 dilution of cattle faeces, spiking with 400 ng/mL cortisol, cortisone or cortisol glucuronide
and incubation of the suspension, was used. The analyses were performed by HPLC–MS3 to detect the supposed Delta1 dehydrogenation of the glucocorticoids. The decision limits (CCalfa) and detection capabilities
(CCbeta) were 2.0 and 3.0 ng/mL for cortisol, cortisone and prednisolone, 3.0 and 4.0 ng/mL for cortisol glucuronide and 7.0 and 10.0 ng/mL for prednisone, respectively. Intra-day and inter-day coefficients of variation (CV%), were 5.6–6.2 and 5.2–6.6 for cortisol glucuronide, cortisol, cortisone and prednisolone,
and 16.0 and 16.2 for prednisone, respectively. The recoveries were in the range 110–143% for all analytes.
Regression coefficients (R2) were in the range 0.996–0.999 for all analytes. The resultsshowthe hydrolysis of the conjugated form and the dehydrogenation in ring A in diluted faeces. It is therefore predicted that urine contaminated with faeces may be positive for prednisone and prednisolone in the same way as they are positive for boldenone, i.e. as a result of microbiological dehydrogenase activity on cortisol and cortisone
HPLC-HRMS methods in horse doping control and forensic veterinary toxicology : a case report about the analysis of anticoagulants
No full textA routine high pressure liquid chromatography-high resolution mass spectrometry (HPLC-HRMS) screening method used for horse doping control in blood and urine was used to identify the likely poisoning of a horse in a 1 ml of gastric, hemorrhagic blood. The veterinarian diagnosis hypothesized the ingestion of a substance belonging to the class of anticoagulants, widely used in agricultural and urban rodent control. Three methodological protocols for the detection of anticoagulant rodenticides in biological tissues were used. As a first step, the screening method of the laboratory, consisting in solid phase extraction (SPE) extraction and HPLC-HRMS analysis, was used: the unknown poison was thus identified as Coumachlor (anticoagulant of the first generation). On the basis of this result, we performed a simple and very fast liquid-liquid extraction followed by ultra high pressure liquid chromatography (UHPLC) HRMS (6 min) analisys for the screening of 8 rodenticides plus embutramide, an active principle of Tanax, a medicine used for euthanasia in veterinary practice. All these substances are of interest in forensic veterinary toxicology. The HRMS analysis was coupled to activated Collision Induced Dissociation (CID) to obtain a further confirmation. The instrument was operated in electrospray ionization, with positive-negative polarity switching mode (1 sec). The resolution was set at 25,000. The final analyses were performed both with a Triple Quadrupole and a Linear Ion Trap mass spectrometer and confirmed the results obtained by HRMS operating in CID mode, so demonstrating the fitness of the method also for confirmation analyses. The limit of detection (LOD) and limit of quantification (LOQ) were calculated for all the analytes. Operating in CID-HRMS, classic doping substances like Methylprednisolone, Bumethanide, was detected and confirmed. The UHPLC-HRMS analisys was also tested on blood from an horse in treatment, for navicular syndrome, with warfarin
In vitro transformation of boldenone and related steroids in veal faeces : preliminary results
No full textPrednisolone and prednisone neo-formation in bovine urine after sampling
No full textThe rise in the frequency of detecting prednisolone in bovine urine from northern Italy has come into focus of attention in recent
years. The possibility that neo-formation of prednisolone or that prednisone may occur in urine after collection of samples was
therefore investigated. Cow urine collected for official routine controls in Lombardy containing more than 80 ng/ml cortisol,
and prednisolone and prednisone below the decision limit (CCa) of the method (0.4 and 0.5 ng/ml, respectively) was used.
The C1–2 dehydrogenation of naturally present cortisol and cortisone was checked by incubating urine, both contaminated and
uncontaminated with faeces, at 378C and by collecting samples at 0, 1, 2, 4, 6 and 24 h. The influence of Helix pomatia juice
was also investigated in order to determine whether deconjugation could influence the reliability of the results. All samples were
analysed by HPLC-MS3 for the presence of cortisol, cortisone, prednisolone and prednisone in negative electrospray ionisation
mode, utilising the consecutive reaction monitoring of product ions derived from the formate molecular adduct ([M1HCOO]–).
The observed neo-formation of prednisolone shows that inappropriate temperatures in sample storage and processing can result
in an incorrect accusation of non-compliance. The faecal contamination of urine, performed with the aim to mimic a collection
conducted without the necessary care, moreover, evoked a high increase in prednisolone concentration in two out of seven
animals. Moreover, H. pomatia juice had no significant effect on the prednisolone concentration, indicating that this
corticosteroid is present in its free form in cow urine
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Presence of prednisolone in complementary feedstuffs for bovine husbandry
Full text linkBACKGROUND: According to European Union legislation, prednisolone, a steroid that belongs to the glucocorticosteroid group,
is banned as a growth promoter in cattle husbandry and therefore should not be present in bovine feedstuffs. As our preliminary
investigations detected prednisolone in this matrix, we performed a study on different commercially available complementary
feedstuffs, stored at the farm and/or in the laboratory, in order to verify whether its presence was due to neo-formation during
storage.
RESULTS: Prednisolonewas detected in almost all (95%) feedstuffs collected at the farm.When the feedstuffswere stored at the
laboratory, the frequency (31%) and the concentration of prednisolone-positiveswere lower. This difference, which is likely due
to different environmental conditions, implies the possibility of its neo-formation.
CONCLUSION: Our data indicate that the neo-formation of prednisolone can occur in feedstuff, and that the frequency and
concentration could be related to the storage conditions. The individuation of an objective parameter that is useful for the
identification of the compliance of feed is therefore essential
Qualitative screening in doping control by MALDI-TOF/TOF mass spectrometry: A proof-of-evidence
No full textPresence of endogenous prednisolone in human urine
No full textThe possibility of an endogenous presence of the glucocorticoid prednisolone has already been demonstrated
in bovine and horse urine, with the aim of clarifying its origin in this matrix, which is used by
official agencies for the control of illicit treatments. From this point of view, the endogenous nature of
prednisolone could be a major topic in doping control of both amateur and professional human athletes.
A study was therefore made on 34 human volunteers (13 males and 21 females; aged 22–62) to detect
the presence of prednisolone in their urine by HPLC–MS3. One of the volunteers underwent vernal allergy
treatment with betamethasone for two subsequent years. An investigation was carried out with the aim
of verifying if the suppression, and the circadian rhythm, of cortisol urinary levels could also apply to
prednisolone. The results of the study show that prednisolone was present in the urine of all 34 volunteers,
with a concentration very close to 100-times lower that of cortisol, with no dependence on gender.
The same ratio (1/100) was observed in the prednisolone and cortisol levels detected during the 24 h
together with the suppression of prednisolone by betamethasone treatment.
These data demonstrate the endogenous nature of low concentrations of prednisolone in human urine,
and motivate further studies about the biosynthetic pathways of this corticosteroid and its relationship
with stress in humans, as already described in cows
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