Papers by Fabiana Landoni
Avian Diseases, 2002
Minimum inhibitory concentrations (MICs) were determined in vitro for 7 antibiotics (aivlosin, en... more Minimum inhibitory concentrations (MICs) were determined in vitro for 7 antibiotics (aivlosin, enrofloxacine, tylosin, tiamulin, kitasamycin, chlortetracycline, and oxytetracycline) against eight recent local Argentinean isolates and two standard strains of Mycoplasma synoviae. Aivlosin (3-acetyl-4"-isovaleryl tylosin tartrate), tylosin, and tiamulin showed the lowest MICs with MIC90s of 0.006, 0.012, and 0.05 microg/ml, respectively. Except one strain that showed resistant values to chlortetracycline (> or = 12.5 microg/ml), all the analyzed strains were susceptible in different degrees to all the antibiotics tested. In this study, the improved activity of the tylosin-derived drug, aivlosin, was confirmed because it showed, in most strains, MIC values half those for tylosin.
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Journal of Veterinary Pharmacology and Therapeutics, 2015
ABSTRACT Cefuroxime pharmacokinetic profile was investigated in 6 Beagle dogs after single intrav... more ABSTRACT Cefuroxime pharmacokinetic profile was investigated in 6 Beagle dogs after single intravenous, intramuscular, and subcutaneous administration at a dosage of 20 mg/kg. Blood samples were withdrawn at predetermined times over a 12-h period. Cefuroxime plasma concentrations were determined by HPLC. Data were analyzed by compartmental analysis. Peak plasma concentration (Cmax ), time-to-peak plasma concentration (Tmax ), and bioavailability for the intramuscular and subcutaneous administration were (mean ± SD) 22.99 ± 7.87 μg/mL, 0.43 ± 0.20 h, and 79.70 ± 14.43% and 15.37 ± 3.07 μg/mL, 0.99 ± 0.10 h, and 77.22 ± 21.41%, respectively. Elimination half-lives and mean residence time for the intravenous, intramuscular, and subcutaneous administration were 1.12 ± 0.19 h and 1.49 ± 0.21 h; 1.13 ± 0.13 and 1.79 ± 0.24 h; and 1.04 ± 0.23 h and 2.21 ± 0.23 h, respectively. Significant differences were found between routes for Ka , MAT, Cmax , Tmax , t½(a) , and MRT. T > MIC = 50%, considering a MIC of 1 μg/mL, was 11 h for intravenous and intramuscular administration and 12 h for the subcutaneous route. When a MIC of 4 μg/mL is considered, T > MIC = 50% for intramuscular and subcutaneous administration was estimated in 8 h. © 2015 John Wiley & Sons Ltd.
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Veterinary Science Development, 2015
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Research in veterinary science, 1996
The pharmacodynamics and enantioselective pharmacokinetics of the arylpropionic acid non-steroida... more The pharmacodynamics and enantioselective pharmacokinetics of the arylpropionic acid non-steroidal anti-inflammatory drug, carprofen, were investigated in cats after administration of the racemic mixture (rac-carprofen) at dose rates ranging from 0.7 to 4.0 mg kg-1 intravenously and subcutaneously. A low dose of rac-carprofen (0.7 mg kg-1) partially inhibited the rise in skin temperature at a site of acute inflammation but had no effect on the ex vivo synthesis of serum thromboxane (Tx) B2. A higher dose (4.0 mg kg-1) inhibited oedematous swelling, although the response was statistically significant at only one time, and also reduced the ex vivo synthesis of serum TxB2 for 12 hours after intravenous injection or 24 hours after subcutaneous injection. The main features of carprofen pharmacokinetics were a low distribution volume, a relatively long elimination half-life, the predominance of the R(-) enantiomer and a bioavailability (after subcutaneous dosing) of 100 per cent and 92 pe...
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Medicina, 2003
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Revue scientifique et technique (International Office of Epizootics), 1992
The tissue distribution of a long-acting oxytetracycline formulation after intramuscular administ... more The tissue distribution of a long-acting oxytetracycline formulation after intramuscular administration to calves at a dose rate of 20 mg/kg was studied. Oxytetracycline concentrations were determined in lung, bone marrow, mammary gland, uterus, uterine horn, ovary, liver, synovial fluid, joint tissue, kidney, spleen, brain, muscle, fat, urine, bile, saliva, ruminal content and serum. Observed concentrations were higher than the minimal inhibitory concentration for the majority of pathogens in all of the analysed tissues for at least 72 h post-injection. The shortest theoretical permanency time was 1.88 days (in saliva) and the longest was 19.06 days (in kidney). Taking the maximal permitted residue level as 0.1 microgram/g in muscle, 0.3 microgram/g in liver and 0.6 microgram/g in kidney, the calculated withdrawal time was 20 days.
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Veterinary Science Development, 2012
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Veterinary Journal, 2009
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Veterinary Research Communications, 1993
The pharmacokinetics of thiamphenicol were studied after intravenous and intramuscular administra... more The pharmacokinetics of thiamphenicol were studied after intravenous and intramuscular administration of 25 mg/kg body weight in lactating cows. Distribution (t1/2 alpha) and elimination (t1/2 beta) half-lives of 6.10 +/- 1.39 min and 1.60 +/- 0.30 h, respectively, were obtained after intravenous administration. The body clearance was 3.9 +/- 0.077 ml/kg per min and the apparent volume of distribution was 1220.79 +/- 256.67 ml/kg. The rate at which thiamphenicol appeared in the milk, as indicated by the penetration half-life (t1/2P) (serum to quarters), was found to be 36.89 +/- 11.14 min. The equivalent elimination half-life (t1/2E) (quarters to serum) from the milk was 3.62 +/- 1.06 h and the peak thiamphenicol concentration in the milk was 23.09 +/- 3.42 micrograms/ml at 2.5 +/- 0.32 h. After intramuscular injection, the elimination half-life was 2.2 +/- 0.40 h, the absorption half-life was 4.02 +/- 1.72 min and the peak concentration in the serum was 30.90 +/- 5.24 micrograms/ml at 23 +/- 8.4 min. The bioavailability after intramuscular administration approached 100%. The penetration half-life was 50.59 +/- 6.87 min, the elimination half-life was 5.91 +/- 4.97 h and the mean peak concentration in the milk was 17.37 +/- 2.20 micrograms/ml at 3.4 +/- 0.22 h.
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Veterinary Research Communications, 1992
The pharmacokinetics of a slow-release theophylline formulation was investigated following intrav... more The pharmacokinetics of a slow-release theophylline formulation was investigated following intravenous and oral administration at 10 mg/kg in horses. A tricompartmental model was selected to describe the intravenous plasma profile. The elimination half-life (t1/2 beta) was 16.91 +/- 0.93 h, the apparent volume of distribution (Vd) was 1.35 +/- 0.18 L/kg and the body clearance (ClB) was 0.061 +/- 0.009 L kg-1 h. After oral administration the half-life of absorption was 1.24 +/- 0.30 h, and the calculated bioavailability was above 100%. The t1/2 beta after oral administration was 18.51 +/- 1.75 h, only a little longer than that after intravenous administration. The slow release formulation did not exhibit any advantage in prolonging the t1/2 beta of theophylline in the horse.
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Journal of Veterinary Medicine Series A, 2000
ABSTRACT Serum concentrations of ticarcillin were measured serially over a period of 12h in a cro... more ABSTRACT Serum concentrations of ticarcillin were measured serially over a period of 12h in a cross over trial involving 6 healthy adult ewes after intravenous and intramuscular (IM) administration of 40 mg ticarcillin per kg body weight. Probenecid (40 mg/kg) was also administered IM immediately before the IM administration of 40 mg/kg ticarcillin. Pharmacokinetic values after intravenous administration were: half-life of elimination (T 1/2 beta) = 0.90 +/- 0.09 h; volume of distribution at steady state (Vdss) = 456.8 +/- 106.6 ml/kg, total body clearance (CIB) = 614.5 +/- 81.2 ml/h/kg. Ticarcillin persisted in serum at greater than or equal to 1.5 micrograms/ml for 4 hours. Pharmacokinetic and bioavailability values after intramuscular administration were: half-life of absorption (T 1/2 ab) = 8.08 +/- 1.98 min; T 1/2 beta = 0.96 +/- 0.07 h. Peak serum concentration (Cmax) was 31.11 +/- 6.02 micrograms/ml at 0.50 h (Tmax), bioavailability (F) was 0.82 +/- 0.09. After ticarcillin was administered IM together with probenecid the T 1/2 ab was 33.9 +/- 13.7 min, the T 1/2 beta 2.66 +/- 0.65 h, Cmax = 44.87 +/- 5.58 at 1.33 +/- 0.44 h, and F = 1.25 +/- 0.23.
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Journal of Veterinary Medicine Series A, 2000
The pharmacokinetics and bioavailability of neomycin in sheep were investigated following intrave... more The pharmacokinetics and bioavailability of neomycin in sheep were investigated following intravenous, intramuscular, subcutaneous and intratracheal administration of 10 mg/kg. A rapid distribution phase (t 1/2 alpha, 3.16 min) was followed by a slower elimination phase (t1/2 beta, 1.98 h). The apparent volume of distribution was 304.69 ml/kg. Absorption half-lives were 18.62, 21.22 and 40.83 min and elimination half-lives 2.68, 2.82 and 2.55 h after IM, SC and IT administration, respectively. Bioavailabilities between 0.74 and 0.85 were obtained for the three routes of administration. Based on the bioavailability and disposition kinetics of neomycin, a twice daily IM dosage regimen should both be practical and adequate to maintain plasma neomycin concentrations within the pharmacologically active but nontoxic range.
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Veterinary Record, 1995
The pharmacodynamics of the non-steroidal anti-inflammatory drugs flunixin, tolfenamic acid and k... more The pharmacodynamics of the non-steroidal anti-inflammatory drugs flunixin, tolfenamic acid and ketoprofen were studied in calves after intravenous administration. An acute inflammatory reaction was induced in tissue cages by the intracaveal injection of the mild irritant carrageenan, and the inhibition of inflammatory mediators and enzymes was investigated. The substances measured in the exudate included the enzymes (active and total metalloproteases, serine and cysteine proteases, acid phosphatase [AP], lactate dehydrogenase [LDH] and beta-glucuronidase) and the eicosanoids (prostaglandin [PG]E2 and leukotriene [LT]B4). Studies were also made of inhibition of the synthesis of serum thromboxane (Tx)B2 ex vivo, of bradykinin-induced oedema in vivo and of the generation of superoxide anions (O2-) in vitro. None of the drugs affected the concentration of LTB4, or the activities of metalloproteases, cysteine and serine proteases, AP or LDH in the exudate. All the drugs inhibited the synthesis of serum TxB2 and exudate PGE2 and inhibited the release of beta-glucuronidase. They also decreased the oedematous response to intradermally injected bradykinin and inhibited the generation of O2- ions by neutrophils in vitro. These actions may contribute to the anti-inflammatory effects of the drugs and hence to their clinical efficacy.
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The Veterinary Journal, 2009
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The Veterinary Journal, 2010
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The Veterinary Journal, 2011
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The Veterinary Journal, 2010
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The Veterinary Journal, 2005
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The Veterinary Journal, 2006
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Papers by Fabiana Landoni