bluuebunny/crossref_metadata_2025_split huggingface dataset:
The pharmacokinetics and tissue levels of polymyxin B, colistin and gentamicin in calves
Authors: ZIV G. , NOUWS J. F. M. , VAN GINNEKEN C. A. M. 
Published: April 2008

Following a single intravenous injection of polymyxin B, colistin (5 mg/kg, each) and gentamicin (3 mg/kg) to calves, the decline in serum antibiotic concentration generally suggested a three‐compartment (open system) pharmacokinetic model. Tissue binding is a dominant factor in the distribution and elimination kinetics of the drugs. Less than 65% of the dose of polymyxin B and colistin was recovered in the urine during 48 h after treatment. Concentrations of nonbound polymyxin B and colistin in the kidney, liver, lung, heart, and skeletal muscles were similar to total (free and bound) serum drug levels, but considerably higher concentrations were found, in bound form, in chloroform‐ethanol extracts of these organs.At 24 h after treatment, more than 50% of the doses of polymyxin B and colistin were present bound to the tissues; the largest amount was in the skeletal muscles. Gentamicin was concentrated in the kidney, predominantly in the free form. At 48 h after treatment the amount of gentamicin in the kidney was 6.3% of the administered dose, being more than five times greater than the corresponding amounts of polymyxin B and colistin.The extent of tissue uptake of polymyxin B and colistin limits the usefulness of kinetic values, which are derived from the analysis of serum drug levels, for the purpose of designing dosage schedules. The strong affinity of the polymyxins to the muscle tissue, and gentamicin to the kidney, can result in drug residues persisting in the body for several weeks.
Autonomic and autacoid activity in antigen‐sensitized and control ovine pulmonary vein and artery
Authors: MIRBAHAR K. B. , EYRE P. 
Published: April 2008

Spirally cut strips of ovine pulmonary vein and artery were studied in isolated organ baths and their responses to selected autacoid and autonomic agents were compared. In addition blood vessels taken from horse plasma‐sensitized sheep were compared with their respective controls. Pulmonary vein and artery exhibited qualitative and quantitative differences in their autacoid and autonomic reactivity. Veins were more sensitive in responding with contractions to histamine (HIST) and carbachol (CARB) when compared with arteries. Responses of these vessels differed qualitatively to 5‐Hydroxytryptamine (5HT); phenylephrine (PE) and adrenaline (ADR): arteries responded with strong contraction and veins with relaxations. Isoproterenol (ISOP) effectively relaxed veins but was either without effect or produced 10%–15% relaxations of precontracted arterial strips. Phentolamine competitively antagonized ADR and PE‐induced contractile responses of arteries while on veins, ISOP and PE dose—response curves (DRCs) were shifted to the right in the presence of propranolol. Mepyramine inhibited venous and arterial responses to HIST.Comparisons between sensitized and non‐sensitized sheep vasculature revealed a significant (P < 0.05) decrease in the activity of spasmolytic agonists on veins, i.e. relaxant actions of 5HT, PE and ISOP were significantly impaired. In addition the activity of 5HT to contract pulmonary artery was significantly (P < 0.05) increased when compared with controls. Present investigation suggests: (i) the predominance of H1‐histaminergic receptors in ovine pulmonary vasculature; (ii) the preponderance of α and β‐adrenergic receptors in pulmonary artery and vein, respectively; (iii) that antigenic sensitization exaggerates the pathological state by causing a decrease in spasmolytic activity with a parallel increase in spasmogenic activity.
Clinical pharmacology and pharmacokinetics of flumequine after intravenous, intramuscular and oral administration in pigeons (Columba livid)
Authors: DORRESTEIN G. M. , GOGH H. VAN , BUITELAAR M. N. , NOUWS J. F. M. 
Published: April 2008

Dorrestein, G.M., Gogh, H. van, Buitelaar, M.N. & Nouws, J.F.M. Clinical pharmacology and pharmacokinetics of flumequine after intravenous, intramuscular and oral administration in pigeons (Columba livia). J. vet. Pharmacol. Therap. 6, 281–292.The in‐vitro activity of flumequine against 157 strains of bacteria isolated from birds was determined. The minimum inhibitory concentration (MIC) of 96.3% of the Enterobacteriaceae, Proteus spp. and Yersinia pseudotuberculosis studied (n = 135) was ≤1 μg/ml. Pharmacokinetics of flumequine in pigeons (Columbalivia) was investigated after intravenous, intramuscular and oral administration. From the blood disappearance curves after i.v. bolus injection (10 mg/kg body weight) clearance rate, blood half‐time and distribution volume were calculated. The recovery of unchanged flumequine from the droppings in 24 h was 37 ± 10% of the administered dose. Flumequine was also given i.m. at two dose levels, 10 and 60 mg/kg body weight. The availability of flumequine as intact drug was 22 and 23%, respectively, in 24 h. Therapeutic blood levels were maintained for 4 and 10 h, respectively. After an oral dose of flumequine (60 mg/kg body weight) an availability of 6.7 ± 2.5% and a peak blood concentration of 2.68 ± 0.92 μg/ml at 2 h after administration were found. The recovery of unchanged flumequine from the droppings in 24 h was 1.55 ± 0.79% of the administered dose. With the exception of the i.m. dose of 10 mg/kg, all flumequine administrations made the pigeons vomit. It appears that blood concentrations below 3 μg/ml will not induce vomiting. On the basis of the present data, a dosage regimen for flumequine in pigeons of a priming dose of 30 mg/kg i.m., followed after 8 h by oral administration of 30 mg/kg, this dose being repeated every 8–12 h, would be expected to give blood concentrations between 1.44 and 2.88 μg/ml.
Comparison of pharmacokinetic parameters for two oxytetracycline preparations in pigs
Authors: XIA WENJIANG , GYRD‐HANSEN NILS , NIELSEN POUL 
Published: April 2008

Pharmacokinetics of oxytetracycline (OTC) were studied in 10 pigs after administration of 20 mg/kg body weight of either a conventional (OTC‐C) or a long‐acting (OTC‐LA) preparation.After intravenous administration of OTC‐C the elimination half‐life for OTC was 3.75 h, with approximately 75% of the dose being excreted in the urine in 1 week. Intramuscular (i.m.) injection of OTC‐C resulted in plasma peak values after 4 h, while OTC‐LA after i.m. administration produced the highest plasma levels within 1 h, although these were lower than with OTC‐C.For both preparations the bioavailability after i.m. administration was 95–100% and about 70% of the dose was excreted in the urine during the first week.With OTC‐C given i.m., plasma concentrations above 0.5 μg/ml were maintained for 28 h and with OTC‐LA for 35 h indicating a weak retard effect of the latter.Pronounced tissue damage at the injection site was seen 1 and 2 weeks after the administration of OTC‐LA, while OTC‐C produced very little irritation. OTC could be found at the injection site for 2 weeks, the concentrations being higher for OTC‐LA than for OTC‐C.
The biology, pathophysiology and control of eicosanoids in inflammation
Authors: HIGGINS A. J. 
Published: April 2008

Higgins, A.J. The biology, pathophysiology and control of eicosanoids in inflammation. J. vet. Pluirmacol. Therap. 8, 1–18.The involvement in inflammatory conditions of those cyclo‐oxygenase and lipoxygenase derivatives of arachidonic acid (5, 8, 11, 14‐eicosatetraenoic acid), which are known as the eicosanoids, is reviewed iti the light of recent studies. Although it is now generally recognized that cyclo‐oxygenase products are fundamental to the inflammatory process as chemical mediators, and that inhibition of the cyclo‐oxygenase enzyme pathway explains the mode of action of most non‐steroidal anti‐inflammatory drugs (NSAIDs) commonly prescribed in veterinary practice, evidence for the involvement of lipoxygenase products of arachidonate metabolism in inflammation is increasing. The leukotrienes (LTs) are 5‐lipoxygenase‐derived eicosanoids which have been shown to be leucotactic and involved in anaphylactic and hypersensitivity reactions. Leucocytes, drawn to sites of injury by chemotaxis, themselves liberate pro‐inflammatory eicosanoids which perpetuate the response and may aggravate the clinical condition. At therapeutic dose rates, most NSAIDs have no effect on the biosynthesis of LTs, whereas corticosteroids, by inhibiting the release of arachidonic acid, may prevent the formation of both cyclo‐oxygenase and lipoxygenase products. However, because of the undesirable side‐effects of steroids, the clinical use of these agents in treating inflammatory conditions is sometimes limited. Novel non‐steroid inhibitors of cyclo‐oxygenase and lipoxygenase enzyme pathways could offer more effective and safer control of inflammation in animals. A.J. Higgins, The Royal Veterinaiy College, North Mymms, Hatfield, Hertfordshire AL9 7TA, England.
Pharmacokinetics of ivermectin in sheep following intravenous, intra‐abomasal or intraruminal administration*
Authors: PRICHARD R. K. , STEEL J. W. , LACEY E. , HENNESSY D. R. 
Published: April 2008

Prichard, R.K., Steel, J.W., Lacey, E. & Hennessy, D.R. Pharmacokinetics of ivermectin in sheep following intravenous, intra‐abomasal, or intraruminal administration. J. vet. Pharmacol. Therap. 8, 88–94.The pharmacokinetics of ivermectin in plasma following intravenous, intra‐abomasal, and intraruminal administration to sheep was determined. When given intravenously, ivermectin was very slowly eliminated with a terminal half‐life of 178 h and a volume of distribution at steady state of 5.3 l/kg indicating sequestration in a temporary depot. Intra‐abomasal administration resulted in rapid absorption, a peak plasma concentration of 6O.6 ng/ml at 4.4 h, and 100% bioavailability. However, intraruminal administration produced a much lower peak concentration (17.6 ng/ml at 23.5 h) and bioavailability (25.1%). A subsequent in vitro study indicated that ivermectin may be rapidly metabolized in the rumen. Dr.J. W. Steel, CSIRO Division of Animal Health, McMaster Lahoratory, Private Bag No. 1, P.O., Glebe, NSW 2037, Australia.
Pharmacokinetics of cefaronide, ceftriaxone and cefoperazone in sheep
Authors: GUERRINI V. H. , FILIPPICH L. J. , CAO G. R. , ENGLISH P. B. , BOURNE D. W. A. 
Published: April 2008

Guerrini, V.H., Filippich, L.J., Cao, G.R., English, P.B. & Bourne, D.W.A. Pharmacokinetics of cefaronide, ceftriaxone and cefoperazone in sheep. J. vet. Pharmacol. Therap. 8, 120–127.The pharmacokinetics of cefaronide (16gm/kg dose), ceftriaxone and cefoperazone (47gm/kg dose), after intravenous (i.v.) administration were determined in six Merino ewes. The mean values for terminal half life, steady state volume of distribution Vd(ss), renal clearance (ClR) and total body clearance (ClB) for cefaronide were 1.5 h, 0.39l/kg, 0.06l/h/kg and 0.16l/h/kg, for ceftriaxone; 1.7 h, 0.30l/kg, 0.08l/h/kg, and 0.22l/h/kg, and 0.7 h, 0.16l/kg, 0.02l/h/kg and 0.16l/h/kg for cefoperazone, respectively. After 5.5 h, approximately 42% cefaronide, and after 8 h, approximately 37% ceftriaxone and 13% cefoperazone, was excreted in urine.The non‐renal elimination of ceftriaxone and cefoperazone appeared to be more rapid in sheep than is reported in man. Cefaronide was excreted largely unchanged in the urine of sheep. Therefore, the elimination of cefaronide in sheep was similar to that found in man. Cefaronide was well distributed in sheep, whereas ceftriaxone and cefoperazone appeared to be distributed to a lesser degree. These Findings underline the different disposition of drugs in different species. Dr V. H. Guerrini, Department of Pharmacy, University of Queensland, St Lucia, QLD 4067, Australia.
Effect of lidamidine‐HCl on Escherichia coli heat‐stable enterotoxin‐induced jejunal water and electrolyte secretion in neonatal piglets
Authors: MERRITT A. M. , BERKHOFF H. , HASKELL M. , WILSON J. 
Published: April 2008

Merritt, A.M., Berkhoff, H., Haskell, M. & Wilson, J. Effect of lidamidine‐HCl on Escherichia coli heat‐stable enterotoxin‐inducéd jejunal water and electrolyte secretion in neonatal piglets. J. vet. Pharmacol. Therap. 8, 150–156.Neonatal piglets were anesthetized, and two jejunal loops, 20 cm in length, were prepared. Then, either water or 0.12, 0.25, 0.5 or 1.0mg/kg of lidamidine‐HCl was injected intraduodenally on a randomized basis, one treatment per pig. Following this, a crude heat‐stable enterotoxin (ST) preparation produced from E. coli no. 1261 was injected into the proximal jejunal loop, and trypticase soy broth (TSB) (with osmolality adjusted to equal the enterotoxin preparation) was injected into the distal jejunal loop. Piglets remained anesthetized for 3 h and were then killed. Fluid was collected from the loops for measurement of volume and Na, K and CI concentration. Empty loop lengths were measured.There was a significant dose‐related reduction of volume and CI content, and a dose‐related, but not significant, reduction in Na content in ST‐treated loops. A comparison of the mean differences in responses between toxin‐and TSB‐treated loops indicated that the major ‘counter‐toxic’ effect of the lidamidine was a dose‐related increase in water and electrolyte absorption. A. M. Merritt, Department of Medical Sciences, College of Veterinaiy Medicine, University of Florida, Box J‐126, Gainesville, FL 32610, U.S.A.
The effect of prostaglandin E1 on motility of the equine gut
Authors: HUNT J. M. , GERRING E. L. 
Published: April 2008

Hunt, J.M. & Gerring, E.L. The effect of prostaglandin E1 on motility of the equine gut. J. vet. Pharmacol. Therap. 8, 165–173.Prostaglandin E1 was infused intravenously (25, 50 and 75ng/kg/min) in three ponies. Changes in gastrointestinal mechanical and electrical activity were recorded from chronically implanted strain‐gauge force transducers and electrodes. Dose‐dependent responses were obtained: there were significant decreases in electrical spiking activity in the stomach, left large colon and small colon, with a corresponding decrease of activity in the left dorsal colon mechanogram. The small intestine was also affected, showing a decrease in both contraction rate and amplitude, which was more marked in the proximal jejunum than in the ileum. There was an association between these changes in gastrointestinal activity and the presence of discomfort and diminished gut sounds. Judith M. Hunt, Department of Veterinary Surgery and Obstetrics, Royal Veterinary College, Hawkshead Lane, North Mymms, Hertfordshire AL9 7TA, U.K.
An improved radioimmunoassay for the anabolic agent hexoestrol, using a monoclonal antibody
Authors: CARTER A. P. D. , COTTINGHAM J. D. , DIXON S. N. , HEITZMAN R.J. 
Published: April 2008

A monoclonal antibody was raised against hexoestrol coupled to bovine serum albumin. The antibody cross‐reacted with the stilbenes, diethylstilboestrol (10%) and dienoestrol (4%), but had no cross‐reaction (<0.01%) with other anabolic agents.A radioimmunoassay method using the monoclonal antibody has been validated and used to measure residues of hexoestrol in the urine of treated cattle. The limit of detection was 0.6 pg/ml urine at the 95% confidence limit. The results were compared with those obtained using polyclonal antibodies. Although there was a good correlation between the results, the use of monoclonal antibody gave more reliable results than those obtained with available polyclonal antibodies. The monoclonal antibody, because of its quality and theoretically limidess supply, is very suitable for use in large scale screening or monitoring programmes for regulating the use of hexoestrol.
Food Animal Residue Avoidance Databank (FARAD): a pharmacokinetic‐based information resource
Authors: SUNDLOF STEPHEN F. , CRAIGMILL ARTHUR C. , RIVIERE JAMES E. 
Published: April 2008

SummaryThe Food Animal Residue Avoidance Databank (FARAD) is a pilot project funded through the USDA Extension Service. It represents a major effort to compile into a single source large amounts of information on veterinary pharmaceutics, pharmacokinetics and physicochemical properties of drugs and other chemicals used in livestock production. FARAD is a computer‐based system consisting of five data and numerous command files that access the data files to facilitate rapid input and retrieval of the desired information. The data files include (1) proprietary information on all pharmaceutical products approved for use in food animals in the United States; (2) physicochemical information on more than 100 chemicals contained in the databank; (3) regulatory information pertaining to tolerance and action levels of chemical residues in animal products and allowable concentrations of drugs in feed; (4) pharmacokinetic rate and volume constants pertinent to residue depletion modeling in a variety of species; (5) bibliographic citations to which all of the information contained in the databank is referenced. All of the information in FARAD is currently available through three regional access centers in the United States, and direct computer access to the data may become available in the future.
DDAVP‐induced increases in coagulation factor VIII and von Willebrand factor in the plasma of conscious dogs
Authors: JOHNSON G. S. , KRAUS. K. H. , TURRENTINE M. A. , DEAN P. W. 
Published: April 2008

Johnson, G.S., Kraus, K.H., Turrentine, M.A. & Dean P.W. DDAVP‐induced increases in coagulation factor VIII and von Willebrand factor in the plasma of conscious dogs. J. vet. Pharmacol. Therap. 9, 370–375.Infusion of the vasopressin analogue DDAVP into five normal dogs at doses of 0.1–2.0 ng DDAVP per kg body weight induced dose‐dependent increases in the plasma content of coagulation factor VIII and von Willebrand factor. Plasma concentrations of von Willebrand factor (determined antigenically as factor VHI‐related antigen and functionally as coagglutinin cofactor activity) and coagulation factor VIII were measured immediately before and at 10, 30, and 120 min after 10‐min intravenous infusions of DDAVP. The greatest increases in coagulation factor VIII were produced with the 2.0 μg/kg dose. Ten minutes after infusion the mean increase in coagulation factor VIII was 32 units/dl (concentrations of all indices were reported relative to concentrations in a standard canine plasma pool, arbitrarily assigned a concentration of 100 units/dl) and this increase did not change significantly throughout the duration of the experiment. At 10 min post‐infusion, the mean factor VHI‐related antigen concentration increased 81 units/dl (dose = 2.0 μg/kg) and did not change significantly for the duration of the experiment. The maximum mean increase in coagglutinin cofactor activity, 141 units/dl, occurred 10 min after infusion (dose = 1.0 μg/kg). Coagglutinin cofactor activity decreased significantly from peak activity by 120 min post‐infusion
Clinical evaluation of R 51163, a new sedative in cattle
Authors: DEGRYSE A.‐D. , OOMS L. A. A. 
Published: April 2008

Degryse, A.‐D. & Ooms, L. A. A. Clinical evaluation of R 51163, a new sedative in cattle. J. vet. Pharmacol. Therap. 9, 376–384.R 51163, a purine alkyl piperidine derivative, has been shown to produce reliable sedation in cattle of varying age and breed in three different types of experiments: transport and regrouping of cattle which had only been handled occasionally; manipulations and minor interventions; minor and major surgery with or without supplementary local anaesthesia. With dose rates of R 51163 at 0.05 mg/kg i.v. and of 0.10‐0.15 mg/kg i.m. sedation became prominent within 10–15 min and lasted at least 60 min. Caesarian sections were performed under adequate sedation with R 51163 with dose ranging from 0.018 to 0.05 mg/kg i.v. and from 0.075 to 0.10 mg/kg i.m. The data suggest possible increased responsiveness to the drug at the time of calving.
The lack of effect of inoculation with equine influenza vaccine on theophylline pharmacokinetics in the horse
Authors: SHORT C. R. , HORNER M. W. , BLAY. P. K. S. , MOSS. M. S. , EDINGTON N. , CLARKE C.R. 
Published: April 2008

Short, C.R., Horner, M.W., Blay, P.K.S., Moss, M.S., Edington, N. & Clarke, C.R. The lack of effect of inoculation with equine influenza vaccine on theophylline pharmacokinetics in the horse. J. vet. Pharmacol. Therap. 9, 426–432. 1986.Several studies conducted during the past few years have shown that the pharmacokinetics of a variety of drugs may be altered following viral infection or vaccination. The elimination of drugs which are extensively metabolized, such as theophylline, may be prolonged, especially following exposure to RNA viruses such as Type A influenza or similar orthomyxoviruses. The purpose of this study was to determine whether vaccination of horses with equine influenza virus affected pharmacokinetic parameters describing the distribution and elimination of intravenously administered theophylline. Three thoroughbred horses and three ponies were vaccinated with a trivalent vaccine containing inactivated strains of A/Equi 1 (Prague), A/Equi 2 (Miami) and A/Equi 2 (Kentucky 81). Antibody titre, serum interferon concentrations, and the pharmacokinetic parameters t½β, Vc, Vd(ss), Vd(area) and C/B were measured at various intervals after vaccination. Antibody titre increased substantially in only two animals, while plasma interferon was detectable in low concentrations in four subjects. There was no significant change in any parameter describing the pharmacokinetics of theophylline when measured 2, 6, or 12 days after vaccination. It is suggested that the failure of vaccination to substantially increase plasma interferon concentrations, and thereby alter theophylline elimination, was related to the use of an inactivated viral vaccine, the only type available for vaccination of horses against infection with equine influenza. Regular use of such vaccines, as is required by most Racing Authorities, is therefore unlikely to affect drug withdrawal times.
Field evaluation of the oxfendazole pulse release bolus for the chemoprophylaxis of bovine parasitic gastroenteritis: a comparison with three other control strategies
Authors: JACOBS D.E. , FOX M.T. , COWLING G. , FOSTER J. , PITT S. R. , GERRELLI D. 
Published: April 2008

Jacobs, D.E., Fox, M.T., Cowling, C, Foster, J. Pitt, S.R. & Gerrelli, D. Field evaluation of the oxfendazole pulse bolus for the chemoprophylaxis of bovine parasitic gastroenteritis: a comparison with three other control strategies. J. vet. Pharmacol. Therap. 10, 30–36.Three trials were conducted in southern England involving 120 autumn‐born calves to evaluate the ability of an oxfendazole pulse‐release intraluminal device (OPRB) to control parasitic gastroenteritis (PGE). Matched groups were set‐stocked on adjacent paddocks. One group received an OPRB at turn‐out; one was treated with an alternative chemoprophylactic programme; while the third acted as an untreated control. In each trial clinical PGE occurred in the latter group but not in OPRB or alternative strategy groups. The OPRB, the morantel sustained release bolus (MSRB) and fenbendazole administered at 3 and 6 weeks after turn‐out gave similar weight‐gain benefits when compared with untreated controls (P < 0.01), but the growth rate of animals given regular levamisole treatments from July to housing was significantly poorer than the matching OPRB group (P < 0.05) although better than controls. Faecal egg‐output of OPRB calves was reduced by 97.0–99.9% compared with 95.5 and 58.9% for MSRB and fenbendazole treatments. Consequently, the late summer/ autumn peaks in pasture larval counts were considerably reduced in all treatment groups other than the late‐season levamisole strategy which reduced overall egg‐output by only 37.6%. Serum pepsinogen and gastrin values confirmed a greater degree of abomasal disturbance in calves grazing on the more highly contaminated pastures. Incidental lungworm infections became clinically apparent in the control groups of two trials but not in any OPRB or alternative treatment group.