bluuebunny/crossref_metadata_2025_split huggingface dataset:
Population pharmacokinetics of marbofloxacin in aqueous humor after intravenous administration in dogs
Authors: Regnier Alain , Concordet Didier , Schneider Marc , Boisramé Bernard , Toutain Pierre-Louis 
Published: January 2006

Abstract

Objective—To evaluate, by use of population pharmacokinetics,
the disposition of marbofloxacin in the
aqueous humor after IV administration in dogs and
identify its potential usefulness in the prophylaxis and
treatment of intraocular infection.

Animals—63 dogs.

Methods—Dogs received a single dose of marbofloxacin
(2 mg · kg–1, IV) at various time intervals
before cataract surgery. Aqueous humor and blood
samples were collected at the beginning of surgery.
Marbofloxacin concentrations were measured by
high-pressure liquid chromatography. Data were analyzed
with a nonlinear mixed-effect model and, by use
of population pharmacokinetic parameters, the time
course of aqueous humor concentration was simulated
for single doses of 3, 4, and 5.5 mg · kg–1IV.
Pharmacodynamic surrogate markers and measured
aqueous humor concentrations were used to predict
in vivo antimicrobial activity.

Results—A maximum marbofloxacin concentration
of 0.41 ± 0.17 µg·mL–1 was reached in the aqueous
humor 3.5 hours after IV administration. In the postdistributive
phase, marbofloxacin disappeared from
aqueous humor with a half-life of 780 minutes. The
percentage penetration into the aqueous humor was
38%. Predictors of antimicrobial effects of marbofloxacin
(2 mg · kg–1, IV) indicated that growth of the
enterobacteriaceae and certain staphylococcal
species would be inhibited in the aqueous humor.
Marbofloxacin administered IV at a dose of
5.5 mg · kg–1 would be predicted to inhibit growth of
Pseudomonas aeruginosa and all strains of staphylococci
but would not eradicate streptococcal infections.

Conclusions and Clinical Relevance—Marbofloxacin
administered IV can penetrate the aqueous
humor of canine eyes and may be suitable for prophylaxis
or treatment of certain anterior chamber
infections. (Am J Vet Res 2003;64:889–893)
Effect of variable-dose propofol alone and in combination with two fixed doses of ketamine for total intravenous anesthesia in cats
Authors: Ilkiw Jan E. , Pascoe Peter J. , Tripp Linda D. 
Published: January 2006

AbstractObjective—To determine the minimum infusion rate (MIR50) for propofol alone and in combination with ketamine required to attenuate reflexes commonly used in the assessment of anesthetic depth in cats.Animals—6 cats.Procedure—Propofol infusion started at 0.05 to 0.1 mg/kg/min for propofol alone or 0.025 mg/kg/min for propofol and ketamine (low-dose [LD] constant rate infusion [CRI] of 23 µg/kg/min or high-dose [HD] CRI of 46 µg/kg/min), and after 15 minutes, responses of different reflexes were tested. Following a response, the propofol dose was increased by 0.05 mg/kg/min for propofol alone or 0.025 mg/kg/min for propofol and ketamine, and after 15 minutes, reflexes were retested.Results—The MIR50for propofol alone required to attenuate blinking in response to touching the medial canthus or eyelashes; swallowing in response to placement of a finger or laryngoscope in the pharynx; and to toe pinch, tetanus, and tail-clamp stimuli were determined. Addition of LD ketamine to propofol significantly decreased MIR50, compared with propofol alone, for medial canthus, eyelash, finger, toe pinch, and tetanus stimuli but did not change those for laryngoscope or tail-clamp stimuli. Addition of HD ketamine to propofol significantly decreased MIR50, compared with propofol alone, for medial canthus, eyelash, toe pinch, tetanus, and tail-clamp stimuli but did not change finger or laryngoscope responses.Conclusions and Clinical Relevance—Propofol alone or combined with ketamine may be used for total IV anesthesia in healthy cats at the infusion rates determined in this study for attenuation of specific reflex activity. (Am J Vet Res2003;64:907–912)
Correlation of helical and incremental high-resolution thin-section computed tomographic imaging with histomorphometric quantitative evaluation of lungs in dogs
Authors: Morandi Federica , Mattoon John S. , Lakritz Jeffrey , Turk James R. , Wisner Erik R. 
Published: January 2006

AbstractObjective—To develop protocols for helical computed tomography (CT) and axial high-resolution CT (HRCT) of lungs and correlate densitometric CT values with morphometric and histologic data for normal pulmonary tissue in dogs.Animals—8 healthy adult dogs.Procedure—2 dogs were used to establish a protocol for helical CT and HRCT of lungs. Six dogs were used to acquire densitometric CT data regarding normal lungs. After the dogs were euthanatized, their lungs were fixed and sampled for morphometric and histologic evaluation. Four CT acquisitions were compared by means of pairedttests.Results—For normal lung tissue of dogs, mean densitometric CT value obtained during helical CT scans reconstructed in a sharp algorithm was -846 Hounsfield units. Values obtained via helical CT or HRCT acquisitions and reconstructed with sharp or standard algorithms did not differ significantly. Morphometric analysis was used to determine the proportion of lung parenchymal (82%) and nonparenchymal tissue (18%). Alveolar size, estimated by mean linear intercept, was approximately 172 µm, and alveolar surface area-to-volume ratio was 0.024 to 0.026 µm–1. Histologic evaluation confirmed the presence of normal lung tissue.Conclusions and Clinical Relevance—Correlation of densitometric CT data with morphometric and histologic findings and the establishment of helical CT and HRCT protocols were attained; clinical use of this information may facilitate investigation of pulmonary disease in dogs. Sharp helical CT acquisitions were preferred because of better lung parenchyma detail and rapid image acquisitions, compared with HRCT. (Am J Vet Res2003;64:935–944)
Distribution of Escherichia coli O157:H7 within and among cattle operations in pasture-based agricultural areas
Authors: Renter David G. , Sargeant Jan M. , Hungerford Laura L. 
Published: January 2006

AbstractObjective—To determine the distribution ofEscherichia coliO157:H7 in pasture-based cattle production areas.Sample Population—Two 100-km2agricultural areas consisting of 207 pasture, 14 beef-confinement, and 3 dairy locations within 24 cattle operations.Procedure—13,726 samples from cattle, wildlife, and water sources were obtained during an 11-month period.Escherichia coliO157:H7 was identified by use of culture and polymerase chain reaction assays and characterized by pulsed-field gel electrophoresis (PFGE).Results—Odds of recoveringE coliO157:H7 from feeder-aged cattle were > 4 times the odds for cowcalf or dairy cattle. There was no difference in prevalence for pastured versus confined cattle after controlling for production age group. Number of samples collected (37 to 4,829), samples that yieldedE coliO157:H7 (0 to 53), and PFGE subtypes (0 to 48) for each operation varied and were highly correlated. Although most PFGE subtypes were only detected once, 17 subtypes were detected on more than 1 operation. Ten of 12 operations at whichE coliO157:H7 was detected had at least 1 subtype that also was detected on another operation. We did not detect differences in the probability of having the same subtype for adjacent operations, nonadjacent operations in the same study area, or operations in the other study area.Conclusions and Clinical Relevance—Strategies aimed at controllingE coliO157:H7 and specific subtypes should account for the widespread distribution and higher prevalence in feeder-aged cattle regardless of production environment and the fact that adjacent and distant cattle operations can have similar subtypes. (Am J Vet Res2004;65:1367–1376)
Effects of ischemia and the cyclooxygenase inhibitor flunixin on in vitro passage of lipopolysaccharide across equine jejunum
Authors: Tomlinson Julia E. , Blikslager Anthony T. 
Published: January 2006

AbstractObjective—To determine whether ischemia and flunixin affect in vitro lipopolysaccharide (LPS) absorption in samples of the jejunum of horses.Animals—12 horses.Procedure—Horses were anesthetized, a midline celiotomy was performed, and the jejunum was located. Two 30-cm sections of jejunum (60 cm apart) were selected. One segment was designated as control tissue; ischemia was induced in the other segment for 120 minutes. Horses were then euthanatized. Mucosa from each jejunal segment was mounted on Ussing chambers and treated with or without flunixin. Tissues from 6 horses were used to assess permeability to radiolabeled LPS; mucosal samples from the remaining 6 horses were incubated with fluorescent-labeled LPS (FITC-LPS) and examined histologically. Production of tumor necrosis factor-α (TNF-α) and production of LPS-binding protein (LBP) were assessed as indicators of mucosal response to LPS.Results—Ischemia significantly increased mucosal permeability to LPS, but by 180 minutes, the mucosa was not more permeable than control tissue. Flunixin treatment adversely affected intestinal barrier function throughout the experiment but did not result in increased mucosal permeability to LPS. Compared with control tissues, LBP production was increased by ischemia and reduced by exposure to LPS. In ischemic tissue, FITC-LPS entered the lamina propria but TNF-α was produced on the mucosal side only, indicating little response to the absorbed LPS.Conclusions and Clinical Relevance—Ischemia increased LPS passage across equine jejunal mucosa. Flunixin delayed mucosal recovery but did not exacerbate LPS absorption. Evaluation of the clinical importance of flunixin-associated delayed mucosal recovery requires further in vivo investigation. (Am J Vet Res2004;65:1377–1383)
Effect of meloxicam and carprofen on renal function when administered to healthy dogs prior to anesthesia and painful stimulation
Authors: Crandell Dawn E. , Mathews Karol A. , Dyson Doris H. 
Published: January 2006

AbstractObjective—To determine whether administration of the nonsteroidal anti-inflammatory drugs meloxicam or carprofen to healthy dogs that were subsequently anesthetized and subjected to painful electrical stimulation has adverse effects on renal function as measured by glomerular filtration rate (GFR) and evaluation of serum concentrations of urea and creatinine.Animals—6 male and 6 female healthy young-adult Beagles.Procedure—A study was conducted in accordance with a randomized crossover Latin-square design. One of 3 treatments (saline [0.9% NaCl] solution, 0.2 mg of meloxicam/kg, or 4.0 mg of carprofen/kg) was administered IV 1 hour before anesthesia was induced by use of drugs in accordance with a standard anesthetic protocol (butorphanol tartrate and acepromazine maleate as preanesthetic medications, ketamine hydrochloride and diazepam for induction, and maintenance with isoflurane). Anesthetized dogs were subjected to intermittent electrical stimulation for 30 minutes. Direct, mean arterial blood pressure; heart rate; and respiratory rate were monitored. End-tidal isoflurane concentration was maintained at 1.5 times the minimum alveolar concentration. The GFR, as measured by plasma clearance of 99mTc-diethylenetriaminepentaacetic acid, and serum concentrations of serum and creatinine were determined 24 hours after induction of anesthesia.Results—Neither meloxicam nor carprofen significantly affected GFR or serum concentrations of urea and creatinine, compared with values for the saline treatment.Conclusions and Clinical Relevance—When administered 1 hour before onset of anesthesia and painful electrical stimulation, meloxicam or carprofen did not cause clinically important alterations of renal function in young healthy dogs. (Am J Vet Res2004;65:1384–1390)
Effect of a commercial anion dietary supplement on acid-base balance, urine volume, and urinary ion excretion in male goats fed oat or grass hay diets
Authors: Stratton-Phelps Meri , House John K. 
Published: January 2006

AbstractObjective—To determine whether feeding a commercial anionic dietary supplement as a urinary acidifier to male goats may be useful for management of urolithiasis.Animals—8 adult sexually intact male Toggenburg, Saanen, and Nubian goats.Procedure—Goats were randomly assigned by age-, breed-, and weight-matched pairs to an oat or grass hay diet that was fed for 12 days. On days 13 to 14 (early sample collection time before supplementation), measurements were made of blood and urine sodium, potassium, calcium, magnesium, chloride, phosphorus, and sulfur concentrations; blood and urine pH; urine production; and water consumption. During the next 28 days, the anionic dietary supplement was added to the oat and grass hay diets to achieve a dietary cation-anion difference of 0 mEq/100g of dry matter. Blood and urine samples were analyzed during dietary supplementation on days 12 to 13 (middle sample collection time) and 27 to 28 (late sample collection time).Results—Blood bicarbonate, pH, and urine pH of goats fed grass hay and goats fed oat hay were significantly decreased during the middle and late sample collection times, compared with the early sample collection time. Water consumption and urine production in all goats increased significantly during the late sample collection time, compared with the early sample collection time.Conclusions and Clinical Relevance—The anionic dietary supplement used in our study increases urine volume, alters urine ion concentrations, and is an efficacious urinary acidifier in goats. Goats treated with prolonged anionic dietary supplementation should be monitored for secondary osteoporosis from chronic urinary calcium loss. (Am J Vet Res2004;65:1391–1397)
Evaluation of environmental and management-related risk factors associated with chronic mastitis in sows
Authors: Hultén Fredrik , Persson Arne , Eliasson-Selling Lena , Heldmer Eva , Lindberg Maria , Sjögren Urban , Kugelberg Christina , Ehlorsson Carl-Johan 
Published: January 2006

Abstract

Objective—To evaluate environmental and management-related risk factors associated with chronic
mastitis in sows.

Animals—1,254 sows from 76 herds.

Procedure—Prevalence of chronic mastitis was
determined by a veterinarian who performed clinical
examinations at the time of weaning and approximately
1 week later in a sample of the sow population
on each farm. Information concerning environmental
factors and management practices was collected. In
addition, the herd veterinarian made an assessment
of the farmer's skills in swine production.

Results—Use of partly slatted floors in the farrowing
pens, use of disinfectants between batches in the farrowing
and breeding areas, feeding lactating sows
whey, and avoiding cutting or grinding of the piglets'
teeth were significantly associated with a decreased
risk of chronic mastitis. A high hygienic standard on
the farm, as determined by the herd veterinarian, was
associated with a significant reduction in the prevalence
of mastitis.

Conclusions and Clinical Relevance—Chronic mastitis
in sows is a common disease that has a negative
influence on productivity. Results indicate that certain
management practices and environmental factors
influenced the development of mastitis, which may
contribute to the development of methods useful for
controlling the disease. (Am J Vet Res
2004;65:1398–1403)
Comparison of inhibitory effects of glucosamine and mannosamine on bovine articular cartilage degradation in vitro
Authors: Mello David M. , Nielsen Brian D. , Peters Tonia L. , Caron John P. , Orth Michael W. 
Published: January 2006

AbstractObjective—To compare the inhibitory effects of glucosamine and mannosamine on articular cartilage degradation and the effects on chondrocyte viability in vitro.Sample Population—Bovine articular cartilage explants.Procedures—Explants were cultured in commercial medium for 48 hours. Cartilage was exposed to medium containing 10% fetal bovine serum, 10 µg of lipopolysaccharide/mL, and 0.5, 1.0, 2.5, 5.0, and 10.0 mg of glucosamine or mannosamine/mL for 24 hours. Nitric oxide (NO) production (nitrite concentration) and proteoglycan (PG) release (PG concentration) in media were measured . Cartilage extracts were analyzed via zymography to detect gelatinolytic activity. At the end of the experiment, explants were assessed for chondrocyte viability.Results—Addition of lipopolysaccharide resulted in increased NO production and PG release, but no increase in gelatinolytic activity, compared with controls. Glucosamine and mannosamine at concentrations as low as 0.5 mg/mL inhibited NO production. Glucosamine inhibited PG release at a minimum concentration of 1.0 mg/mL, whereas mannosamine inhibited PG release at a concentration of 0.5 mg/mL. Concentrations of glucosamine ≤ 5.0 mg/mL did not adversely affect chondrocyte viability; however, at a concentration of 10.0 mg/mL, cell death was evident. Mannosamine had a toxic effect at a concentration of 5.0 mg/mL and was associated with pronounced chondrocyte death at a concentration of 10.0 mg/mL.Conclusions and Clinical Relevance—Glucosamine and mannosamine inhibit selected indices of bovine articular cartilage degradation at concentrations that do not affect chondrocyte viability. The potential for cytotoxic effects at higher concentrations underscores the importance of establishing appropriate dosage regimens for these aminomonosaccharides. (Am J Vet Res2004;65:1440–1445)
Assessment of the ability of Malassezia pachydermatis to stimulate proliferation of canine keratinocytes in vitro
Authors: Chen Tai-An , Halliwell Richard E. W. , Shaw Darren J. , Hill Peter B. 
Published: January 2006

AbstractObjective—To investigate the direct interaction between canine keratinocytes and liveMalassezia pachydermatisand thereby determine the role of these organisms in the pathogenesis of epidermal hyperplasia associated withMalasseziadermatitis in dogs.Sample population—Primary canine keratinocyte cultures established from skin samples obtained from clinically normal dogs.Procedure—The proliferative response of keratinocytes co-cultured withMalasseziaorganisms for 1, 2, or 3 days was assessed by use of direct manual counting (to determine the number of keratinocytes in both the monolayer and the medium) and immunohistochemical staining techniques involving antibodies against proliferating cell nuclear antigen (PCNA) and another cellular proliferation marker, Ki-67. The potential cytotoxic effect ofMalasseziaorganisms was investigated by use of an apoptosis detection kit to label keratinocytes co-cultured withM pachydermatisthat underwent apoptosis.Results—No stimulatory effect ofMalasseziaorganisms on canine keratinocyte proliferation was detected via cell counting and immunohistochemical techniques. However, there was a significant increase in dead keratinocytes in the medium with increasing numbers ofMalasseziaorganisms in the co-culture. More apoptotic cells were observed in keratinocyte monolayers co-cultured with high numbers ofM pachydermatisthan there were in monolayers cultured withoutMalasseziaorganisms, and the number increased after prolonged incubation.Conclusions and Clinical Relevance—M pachydermatisdid not stimulate canine keratinocyte proliferation in vitro. The results suggested that the epidermal hyperplasia observed in dogs withMalasseziadermatitis is unlikely to be caused by a direct effect of the organism on the keratinocyte cell cycle, but is likely to involve other mechanisms.Am J Vet Res(2004;65:787–796)
Myoelectric activity in the intestines of healthy dairy cows during the recovery period after implantation of permanent electrodes
Authors: Meylan Mireille , Eicher Richard , Zulauf Marc , Steiner Adrian 
Published: January 2006

AbstractObjective—To describe myoelectric patterns in the intestines of cows after electrode implantation.Animals—7 lactating Simmental-Red Holstein cows.Procedure—Cows were implanted with 7 pairs of bipolar silver electrodes (1 each in the ileum, cecum, and proximal loop of the ascending colon (PLAC) and 4 in the spiral colon). Myoelectric activity was monitored during 10 periods within the first 3 weeks after surgery. Recordings from the first 2 weeks were compared with recordings from the third week, which was considered a steady-state condition.Results—Significant changes over time were detected for 18 of 57 variables, including 3 variables describing myoelectric activity of the ileum, 6 variables of the cecum, 6 variables of the PLAC, and 3 variables of the spiral colon. Compared with values for the steadystate condition, 16 variables differed significantly for the 14-day period after surgery (7 variables until day 11, 2 variables until day 8, 4 variables until day 5, 1 variable until day 3, and 2 variables until day 2 after electrode implantation). None of the variables had significant changes that lasted only 1 day after surgery.Conclusions and Clinical Relevance—Significant changes were observed for several variables of myoelectric activity in all intestinal segments until as late as 11 days after electrode implantation, whereas a steady-state condition was reached 14 days after surgery. Effects of drugs, manipulations, or nutrition regimens on myoelectric activity of the bovine digestive tract should be evaluated no sooner than 2 weeks after electrode implantation. (Am J Vet Res2004;65:797–805)
Pharmacokinetics of lamivudine in cats
Authors: Zhang Weijiang , Mauldin Jeffrey K. , Schmiedt Chad W. , Brockus Charles W. , Boudinot F. Douglas , Stevenson M. A. McCrackin 
Published: January 2006

AbstractObjective—To characterize the pharmacokinetics of lamivudine (3TC) in cats.Animals—6 sexually intact 9-month-old barrier-reared domestic shorthair cats.Procedure—Cats were randomly alloted into 3 groups, and lamivudine (25 mg/kg) was administered IV, intragastrically (IG), and PO in a 3-way crossover study design with 2-week washout periods between experiments. Plasma samples were collected for 12 hours after drug administration, and lamivudine concentrations were determined by high-performance liquid chromatography. Maximum plasma concentrations (Cmax), time to reach Cmax(Tmax), and bioavailability were compared between IG and PO routes. Area under the curve (AUC) and terminal phase halflife (t½) among the 3 administration routes were also compared.Results—Plasma concentrations of lamivudine declined rapidly with a t½of 1.9 ± 0.21 hours, 2.6 ± 0.66 hours, and 2.7 ± 1.50 hours after IV, IG, and PO administration, respectively. Total body clearance and steady-state volume of distribution were 0.22 ± 0.09 L/h/kg and 0.60 ± 0.22 L/kg, respectively. Mean Tmaxfor IG administration (0.5 hours) was significantly shorter than Tmaxfor PO administration (1.1 hours). The AUC after IV, IG, and PO administration was 130 ± 55.2 mg·h/L, 115 ± 97.5 mg·h/L, and 106 ± 94.9 mg·h/L, respectively. Lamivudine was well absorbed after IG and PO administration with bioavailability values of 88 ± 45% and 80 ± 52%, respectively.Conclusions and Clinical Relevance—Cats had a shorter t½but slower total clearance of lamivudine, compared with humans. Plasma concentrations of lamivudine were maintained above the minimum effective concentration for inhibiting FIV replication by 50% (0.14µM [0.032 µg/mL] for wild-type FIV clinical isolate) for at least 12 hours after IV, IG, or PO administration. (Am J Vet Res2004;65:841–846)