bluuebunny/crossref_metadata_2025 huggingface dataset:
Cardiopulmonary effects of dexmedetomidine in sevoflurane-anesthetized sheep with and without nitric oxide inhalation
Authors: Kästner Sabine B. R. , Kull Susanne , Kutter Annette P. N. , Boller Jolanda , Bettschart-Wolfensberger Regula , Huhtinen Mirja K.
Published: December 2005

Objective—To determine whether inhaled nitric oxide (NO) prevents pulmonary hypertension and improves oxygenation after IV administration of a bolus of dexmedetomidine in anesthetized sheep.

Animals—6 healthy adult sheep.

Procedure—In a crossover study, sevoflurane-anesthetized sheep received dexmedetomidine (2 µg/kg, IV) without NO (DEX treatment) or with inhaled NO (DEX-NO treatment). Cardiopulmonary variables, including respiratory mechanics, were measured before and for 120 minutes after bolus injection of dexmedetomidine.

Results—Dexmedetomidine induced a transient decrease in heart rate and cardiac output. A short-lived increase in mean arterial pressure (MAP) and systemic vascular resistance (SVR) was followed by a significant decrease in MAP and SVR for 90 minutes. Mean pulmonary arterial pressure (MPAP) and pulmonary vascular resistance increased transiently after dexmedetomidine injection. The PaO2was significantly decreased 3 minutes after injection and reached a minimum of (mean ± SEM) 13.3 ± 7.8 kPa 10 minutes after injection. The decrease in PaO2was accompanied by a sudden and prolonged decrease in dynamic compliance and a significant increase in airway resistance, shunt fraction, and alveolar dead space. Peak changes in MPAP did not differ between the 2 treatments. For the DEX-NO treatment, PaO2was significantly lower and the shunt fraction significantly higher than for the DEX treatment.

Conclusions and Clinical Relevance—Inhalation of NO did not prevent increases in pulmonary arterial pressures induced by IV administration of dexmedetomidine. Preemptive inhalation of NO intensified oxygenation impairment, probably through increases in intrapulmonary shunting. (Am J Vet Res2005;66:1496–1502)
Histomorphometric analysis of the proximal portion of the femur in dogs with moderate osteoarthritis
Authors: Sicard Gretchen K. , Markel Mark D. , Manley Paul A.
Published: December 2005

Objective—To describe the histomorphometric properties
of epiphyseal and metaphyseal trabecular bone
of the proximal portion of the femur of dogs with
moderate osteoarthritis.

Sample Population—Proximal portions of a femour
from 24 dogs.

Procedure—The proximal portion of a femur was
obtained from each dog. Eleven and thirteen specimens
were sectioned in the transverse and coronal planes,
respectively. Three evenly spaced sections from each
specimen were chosen, surface stained, and digitized,
and the stained areas were preferentially selected.
Custom software was used for histomorphometric
analysis of each section. A mixed-model analysis was
used to evaluate the effect of slice location and region on
6 parameters, and a Fisher protected t test was used
when differences were detected.

Results—There was a significant difference between
the femoral head and femoral neck for all parameters
tested. In coronal sections, the femoral neck was significantly
more anisotropic than the femoral head. In
transverse sections, the craniolateral region of the
femoral neck was significantly more anisotropic than
the caudomedial and craniomedial regions.

Conclusions and Clinical Relevance—There is a
predictable cancellous microarchitecture in the proximal
portion of femurs from dogs with moderate
osteoarthritis. Trabeculae are more numerous, thicker,
and closer together but more randomly arranged in
the femoral head than in the femoral neck. Dogs with
moderate osteoarthritis had an increase in trabecular
anisotropy in the craniolateral region of the femoral
neck. However, there was no corresponding increase
in trabecular alignment of the proximomedial region
of the femoral head. Results support an association
between trabecular alignment and the progression of
osteoarthritis. ( Am J Vet Res 2005;66:150–155)
Effects of the omega-3 fatty acid, α-linolenic acid, on lipopolysaccharide-challenged synovial explants from horses
Authors: Munsterman Amelia S. , Bertone Alicia L. , Zachos Terri A. , Weisbrode Steven E.
Published: December 2005

Objective—To determine the effects of pretreatment with α-linolenic acid, an omega-3 polyunsaturated fatty acid, on equine synovial explants challenged with lipopolysaccharide (LPS).

Animals—8 mature mixed-breed horses (4 mares and 4 geldings).

Procedure—Synovial explants were assigned to receive 1 of 7 concentrations of α-linolenic acid, ranging from 0 to 300 µg/mL. At each concentration, half of the explants were controls and half were challenged with 0.003 µg of LPS as a model of synovial inflammation. Cell inflammatory response was evaluated by measurement of prostaglandin E2production via an ELISA. Synovial cell viability, function, histomorphologic characteristics, and cell membrane composition were evaluated by use of trypan blue dye exclusion, hexuronic acid assay for hyaluronic acid, objective microscopic scoring, and high-performance liquid chromatography, respectively.

Results—Challenge with LPS significantly increased production of prostaglandin E2and decreased production of hyaluronic acid. Treatment with α-linolenic acid at the highest dose inhibited prostaglandin E2production. Cell viability and histomorphologic characteristics were not altered by treatment with α-linolenic acid or LPS challenge. Treatment with α-linolenic acid increased the percentage of this fatty acid in the explant cell membranes.

Conclusions and Clinical Relevance—Results suggest that investigation of α-linolenic acid as an anti-inflammatory medication for equine synovitis is warranted. (Am J Vet Res2005;66:1503–1508)
Isolation, characterization, and expression of stromelysin-1 in primary tumors of dogs
Authors: Sorensen Kara C. , Newman Rebecca G. , Kitchell Barbara E. , Schaeffer David J. , Siegel Arthur M.
Published: December 2005

Objective—To isolate and characterize the cDNA
sequence of canine stromelysin-1 (matrix metalloproteinase
[MMP]-3), screen various naturally developing
primary tumors of dogs, and assess the effect of
stromelysin-1 on survival of dogs with cancer.

Sample Population—3 canine cell lines and biopsy
specimens of primary tumors collected from 54 dogs.

Procedure—3 canine cell lines and biopsy specimens
of primary tumors collected from 54 dogs at the
University of Illinois Veterinary Teaching Hospital were
used in the study. Primer sets based on human
stromelysin-1 and consensus sequences were
designed for expression, screening, and isolation. Two
additional primer sets were designed for screening.
Samples were assayed at least in duplicate. Data
were analyzed for differences in expression of
stromelysin-1 on the basis of sex, age, metastasis,
malignant versus nonmalignant tissue origin, and
duration of patient survival.

Results—A 1,479-bp cDNA nucleotide sequence was
amplified from established canine cell lines. The open
reading frame encoded a protein consisting of 478
amino acids. This sequence was 70% to 88% homologous
with stromelysin-1 of other species at the
amino acid level. Fifty-four samples were screened
for stromelysin-1. Of these, 34 (63%) had positive
results and 20 (37%) had negative results for expression.
Stromelysin-1 and metastasis were associated
with a poor prognosis for survival.

Conclusions and Clinical Relevance—Stromelysin-1
is a potential activator of other members of the MMP
family. Additional studies are needed to investigate
the relationship between stromelysin-1 production
and aggressive biological behavior of tumors in dogs.
(Am J Vet Res 2005;66:1526–1535)
In vitro biomechanical comparison of a plate-rod combination–construct and an interlocking nail–construct for experimentally induced gap fractures in canine tibiae
Authors: Pfeil Dirsko J. F. von , Déjardin Loïc M. , DeCamp Charles E. , Meyer Eric G. , Lansdowne Jennifer L. , Weerts Robin J. H. , Haut Roger C.
Published: December 2005

Objective—To compare structural properties of a plate-rod combination–bone construct (PRCbc) and interlocking nail–bone construct (ILNbc) by use of an experimentally induced gap fracture in canine tibiae.

Sample Population—12 paired canine tibiae.

Procedure—Specimens were implanted with a plate-rod combination consisting of a 3.5-mm, limited-contact, dynamic-compression plate combined with an intramedullary rod or 6-mm interlocking nail. Ostectomy (removal of 10-mm segment) was performed. Paired constructs were loaded for bending, compression, or torsion measurements (4 constructs/group). Compliance was determined by fitting regression lines to the load-position curves at low (initial compliance) and high (terminal compliance) loads.

Results—Bending compliances did not differ significantly between constructs. For the ILNbc, initial compliance was greater than terminal compliance in compression and torsion. Initial compliance and terminal compliance for the PRCbc were similar in compression and torsion. Initial compliance in compression and torsion was greater for the ILNbc, compared with initial compliance for the PRCbc. Maximum deformations in bending and compression were similar between constructs; however, maximum torsional angle was significantly greater for the ILNbc, compared with values for the PRCbc.

Conclusions and Clinical Relevance—The study documented that for an experimentally induced gap fracture in canine tibiae, a plate-rod combination is a significantly less compliant fixation method in torsion and compression, compared with an interlocking nail. Considering the deleterious effects of torsional deformation on bone healing, a plate-rod combination may represent a biomechanically superior fixation method, compared with an interlocking nail, for the treatment of dogs with comminuted tibial diaphyseal fractures. (Am J Vet Res2005;66:1536–1543)
Pulmonary arterial disease in cats seropositive for Dirofilaria immitis but lacking adult heartworms in the heart and lungs
Authors: Browne Leanne E. , Carter Todd D. , Levy Julie K. , Snyder Patti S. , Johnson Calvin M.
Published: December 2005

Objective—To determine the prevalence and severity
of pulmonary arterial lesions in cats seropositive for
heartworms (Dirofilaria immitis) but lacking adult
heartworms in the heart and lungs during necropsy.

Animals—630 adult cats from an animal control shelter
in Florida.

Procedure—Cats were tested for adult heartworms
in the heart and pulmonary arteries and antibody
against heartworms in the serum. Histologic examination
was conducted on the right caudal lung lobe of
24 heartworm- and antibody-positive cats; 24 heartworm-negative and antibody-positive cats; and 24
heartworm-, antibody-, and antigen-negative cats.
Wall areas of 10 small to medium-sized pulmonary
arteries of each cat were measured and expressed as
a proportion of total cross-sectional area.

Results—Heartworm infection or seropositive status
was significantly and strongly associated with severity
of medial hypertrophy of pulmonary arterial walls.
Heartworm- and antibody-positive cats and heartworm-negative and antibody-positive cats had a significant
increase in wall thickness, compared with
wall thickness for heartworm- and antibody-negative
cats. Heartworm- and antibody-positive cats had the
most severe hypertrophy. The proportion with occlusive
medial hypertrophy was significantly higher in
heartworm- and antibody-positive cats (19/24 [79%])
and heartworm-negative and antibody-positive cats
(12/24 [50%]), compared with heartworm- and antibody-negative cats (3/24 [13%]).

Conclusions and Clinical Relevance—Cats with
serologic evidence of exposure to heartworms,
including those without adult heartworms in the lungs
and heart, have a greater prevalence of pulmonary
arterial lesions than heartworm-negative cats without
serologic evidence of exposure. Additional studies are
needed to define the pathogenesis, specificity, and
clinical importance of these lesions. (Am J Vet Res
2005;66:1544–1549)
Relative sensitivity of polymerase chain reaction assays used for detection of feline herpesvirus type 1 DNA in clinical samples and commercial vaccines
Authors: Maggs David J. , Clarke Heather E.
Published: December 2005

Objective—To determine relative detection rates and detection limits for 6 published polymerase chain reaction (PCR) assays used for detection of feline herpesvirus type 1 (FHV-1) DNA.

Sample Population—5 vaccines licensed for use in preventing FHV-1–associated disease; 15 conjunctival biopsy specimens collected from cats with keratitis, conjunctivitis, or both; and a plaque-purified field isolate of FHV-1 cultured in vitro.

Procedure—Vaccines and clinical samples were assessed for FHV-1 DNA by use of all 6 assays. Detection rates were calculated by assuming that any sample in which FHV-1 DNA was detected was a true-positive result. Detection limits were estimated by use of serial dilutions of DNA extracted from cultured FHV-1 and 1 clinical sample.

Results—Testing by use of all 6 assays resulted in detection of FHV-1 DNA in all 5 vaccines. Testing by use of all 6 assays yielded concordant results for 9 of 15 conjunctival biopsy specimens (8 with negative results and 1 with a positive result). Calculated detection rates for clinical samples ranged from 29% to 86%. Assay sensitivity was ranked similarly by use of detection rate or detection limit.

Conclusions and Clinical Relevance—Testing by use of all assays was equally likely to detect vaccine virus. Therefore, a positive PCR result in a cat may reflect vaccine virus rather than wild-type virus. Test sensitivity as assessed by detection limits and detection rates varied greatly. Because FHV-1 can be shed in clinically normal animals, high detection rate will not necessarily correlate with high diagnostic sensitivity. (Am J Vet Res2005;66:1550–1555)
Effects of routine prophylactic vaccination or administration of aluminum adjuvant alone on allergen-specific serum IgE and IgG responses in allergic dogs
Authors: Tater Kathy C. , Jackson Hilary A. , Paps Judy , Hammerberg Bruce
Published: December 2005

Objective—To determine the acute corn-specific
serum IgE and IgG, total serum IgE, and clinical
responses to SC administration of prophylactic vaccines
and aluminum adjuvant in corn-allergic dogs.

Animals—20 allergic and 8 nonallergic dogs.

Procedure—17 corn-allergic dogs were vaccinated.
Eight clinically normal dogs also were vaccinated as
a control group. Serum corn-specific IgE, corn-specific
IgG, and total IgE concentrations were measured
in each dog before vaccination and 1 and 3
weeks after vaccination by use of an ELISA. The
corn-allergic dogs also had serum immunoglobulin
concentrations measured at 8 and 9 weeks after
vaccination. Twenty allergic dogs received a SC
injection of aluminum adjuvant, and serum
immunoglobulin concentrations were measured in
each dog 1, 2, 3, 4, and 8 weeks after injection. The
allergic dogs were examined during the 8 weeks
after aluminum administration for clinical signs of
allergic disease.

Results—The allergic dogs had significant increases
in serum corn-specific IgE and IgG concentrations 1
and 3 weeks after vaccination but not 8 or 9 weeks
after vaccination. Control dogs did not have a significant
change in serum immunoglobulin concentrations
after vaccination. After injection of aluminum adjuvant,
the allergic dogs did not have a significant
change in serum immunoglobulin concentrations or
clinical signs.

Conclusions and Clinical Relevance—Allergen-specific
IgE and IgG concentrations increase after prophylactic
vaccination in allergic dogs but not in clinically
normal dogs. Prophylactic vaccination of dogs
with food allergies may affect results of serologic
allergen-specific immunoglobulin testing performed
within 8 weeks after vaccination. (Am J Vet Res
2005;66:1572–1577)
Pharmacokinetics of azathioprine following single-dose intravenous and oral administration and effects of azathioprine following chronic oral administration in horses
Authors: White Stephen D. , Maxwell Lara K. , Szabo Nancy J. , Hawkins Jocelyn L. , Kollias-Baker Cynthia
Published: December 2005

Objective—To determine pharmacokinetics of azathioprine (AZA) and clinical, hematologic, and serologic effects of IV and oral administration of AZA in horses.

Animals—6 horses.

Procedure—In study phase 1, a single dose of AZA was administered IV (1.5 mg/kg) or orally (3.0 mg/kg) to 6 horses, with at least 1 week between treatments. Blood samples were collected for AZA and 6-mercaptopurine (6-MP) analysis 1 hour before and at predetermined time points up to 4 hours after AZA administration. In study phase 2, AZA was administered orally (3 mg/kg) every 24 hours for 30 days and then every 48 hours for 30 days. Throughout study phase 2, blood samples were collected for CBC determination and serum biochemical analysis.

Results—Plasma concentrations of AZA and its metabolite, 6-MP, decreased rapidly from plasma following IV administration of AZA, consistent with the short mean elimination half-life of 1.8 minutes. Oral bioavailability of AZA was low, ranging from 1% to 7%. No horses had abnormalities on CBC determination or serum biochemical analysis, other than 1 horse that was lymphopenic on day 5 and 26 of daily treatment. This horse developed facial alopecia from which 1 colony of aTrichophytonsp was cultured; alopecia resolved within 1 month after the study ended.

Conclusions and Clinical Relevance—Overall, no adverse effects were observed with long-term oral administration of AZA to horses, although 1 horse did have possible evidence of immunosuppression with chronic treatment. Further investigation of the clinical efficacy of AZA in the treatment of autoimmune diseases in horses is warranted. (Am J Vet Res2005;66:1578–1583)
Cytokine response of bovine mammary gland epithelial cells to Escherichia coli, coliform culture filtrate, or lipopolysaccharide
Authors: McClenahan David J. , Sotos Josh P. , Czuprynski Charles J.
Published: December 2005

Objective—To define the cytokine response of a cultured mammary gland epithelial cell line (ie, Mac-T) when incubated withEscherichia colior its products.

Sample Population—Mac-T cells andE colifrom cows with mastitis.

Procedure—Mac-T cells were incubated withE colior its products. The cytokine response of Mac-T cells to these treatments was quantified by measuring mRNA content of interleukin (IL)-1α, IL-1β, IL-8, and tumor necrosis factor (TNF)-α by use of a quantitative reverse transcriptase-polymerase chain reaction assay. The amount of TNF-α secreted was also measured.

Results—Treatment withE colior its products resulted in significant increases in IL-1α, IL-8, and TNF-α mRNA content in Mac-T cells. This increase was reversible when culture filtrate was incubated with polymyxin B. The amount of IL-1β mRNA in Mac-T cells increased only slightly over baseline after treatment withE colior its products, but this increase was not diminished by incubation ofE colifiltrate with polymyxin B.

Conclusions and Clinical Relevance—Incubation of Mac-T cells withE colior its products resulted in increased amounts of IL-1α, IL-8, and TNF-α mRNA. Inhibition of this response by incubation of culture filtrate with polymyxin B suggested that lipopolysaccharide was the main bacterial product that stimulated the cytokine response. The small increase in IL-1β content in Mac-T cells incubated withE colior its products suggested that this cytokine had a smaller role in the Mac-T cell response toE coli. (Am J Vet Res2005;66:1590–1597)
Physiologic assessment of blood glucose homeostasis via combined intravenous glucose and insulin testing in horses
Authors: Eiler Hugo , Frank Nicholas , Andrews Frank M. , Oliver Jack W. , Fecteau Kellie A.
Published: December 2005

Objective—To characterize the physiologic response to IV bolus injection of glucose and insulin for development of a combined glucose-insulin test (CGIT) in horses.

Animals—6 healthy mares and 1 mare each with pituitary adenoma and urolithiasis.

Procedure—Horses were given a CGIT (glucose, 150 mg/kg; insulin, 0.1 U/kg); results were compared with a singular IV glucose tolerance test (GTT; 150 mg/kg) and a singular IV insulin sensitivity test (IST; 0.1 U/kg). Healthy horses were also given a CGIT after receiving xylazine and undergoing stress.

Results—Physiologically, the CGIT resulted in a 2-phase curve with positive (hyperglycemic) and negative (hypoglycemic) portions; the positive phase came first (250% of baseline at 1 minute). The descending segment declined linearly to baseline by approximately 30 minutes and to a nadir at 58% of baseline by 75 minutes. After a 35-minute valley, a linear ascent to baseline began. Addition of insulin in the CGIT increased glucose utilization by approximately 4.5 times during the positive phase but not during the negative phase. The diseases' effects and experimental inhibition of insulin secretion with xylazine and stress were detectable by use of the 2 phases of the CGIT. Only a single positive phase resulted from the GTT and a single negative phase from the IST.

Conclusions and Clinical Relevance—The CGIT resulted in a consistent, well-defined glycemia profile, which can be disrupted experimentally or by a disease process. The CGIT has clinical potential because it provides integrated information and more information than either the singular GTT or IST. (Am J Vet Res2005;66:1598–1604)
Assessment of a von Frey device for evaluation of the antinociceptive effects of morphine and its application in pharmacodynamic modeling of morphine in dogs
Authors: KuKanich Butch , Lascelles B. Duncan X. , Papich Mark G.
Published: December 2005

Objective—To assess the use of a von Frey device as a mechanical nociceptive stimulus for evaluation of the antinociceptive effects of morphine in dogs and its potential application in the pharmacodynamic modeling of morphine in that species.

Animals—6 healthy Beagles.

Procedure—von Frey thresholds were measured in all dogs before and at intervals after they received no treatment (control dogs) and IV administration of morphine sulfate (1 mg/kg; treated dogs) in a crossover study. The von Frey device consisted of a rigid tip (0.5 mm in diameter) and an electronic load cell; the operator was unaware of recorded measurements.

Results—Application of the von Frey device was simple and well tolerated by all dogs and caused no apparent tissue damage. No significant changes in thresholds were detected in the control dogs at 8 hourly measurements, indicating a lack of acquired tolerance, learned aversion, or local hyperalgesia. When assessed as a group, treated dogs had significantly high thresholds for 4 hours following morphine administration, compared with baseline values; individually, thresholds decreased to baseline values within (mean ± SE) 2.8 ± 0.6 hours. The maximal effect (change from baseline values) was 213 ± 43%, and the plasma morphine concentration to achieve 50% maximal effect was 13.92 ± 2.39 ng/mL.

Conclusions and Clinical Relevance—Data suggest that, in dogs, evaluation of the antinociceptive effect and pharmacodynamic modeling of a dose of morphine sulfate (1 mg/kg, IV) can be successfully achieved by use of a von Frey device. (Am J Vet Res2005;66:1616–1622)
Functional adaptation through changes in regional biochemical characteristics during maturation of equine superficial digital flexor tendons
Authors: Lin Yi-lo , Brama Pieter A. J. , Kiers Geesje H. , DeGroot Jeroen , Weeren P. René van
Published: December 2005

Objective—To quantify and compare biochemical characteristics of the extracellular matrix (ECM) of specimens harvested from tensional and compressive regions of the superficial digital flexor tendon (SDFT) of horses in age classes that include neonates to mature horses.

Sample Population—Tendon specimens were collected on postmortem examination from 40 juvenile horses (0, 5, 12, and 36 months old) without macroscopically visible signs of tendonitis.

Procedure—Central core specimens of the SDFT were obtained with a 4-mm-diameter biopsy punch from 2 loaded sites, the central part of the midmetacarpal region and the central part of the midsesamoid region. Biochemical characteristics of the collagenous ECM content (ie, collagen, hydroxylysylpyridinoline crosslink, and pentosidine crosslink concentrations and percentage of degraded collagen) and noncollagenous ECM content (percentage of water and glycosaminoglycans, DNA, and hyaluronic acid concentrations) were measured.

Results—The biochemical composition of equine SDFT was not homogeneous at birth with respect to DNA, glycosaminoglycans, and pentosidine concentrations. For most biochemical variables, the amounts present at birth were dissimilar to those found in mature horses. Fast and substantial changes in all components of the matrix occurred in the period of growth and development after birth.

Conclusions and Clinical Relevance—Unlike cartilage, tendon tissue is not biochemically blank (ie, homogeneous) at birth. However, a process of functional adaptation occurs during maturation that changes the composition of equine SDFT from birth to maturity. Understanding of the maturation process of the juvenile equine SDFT may be useful in developing exercise programs that minimize tendon injuries later in life that result from overuse. (Am J Vet Res2005;66:1623–1629)
Evaluation of a lithium dilution cardiac output technique as a method for measurement of cardiac output in anesthetized cats
Authors: Beaulieu Kim E. , Kerr Carolyn L. , McDonell Wayne N.
Published: December 2005

Objective—To evaluate the use of a lithium dilution cardiac output (LiDCO) technique for measurement of CO and determine the agreement between LiDCO and thermodilution CO (TDCO) values in anesthetized cats.

Animals—6 mature cats.

Procedure—Cardiac output in isoflurane-anesthetized cats was measured via each technique. To induce different rates of CO in each cat, anesthesia was maintained at > 1.5X end-tidal minimum alveolar concentration (MAC) of isoflurane and at 1.3X endtidal isoflurane MAC with or without administration of dobutamine (1 to 3 µg/kg/min, IV). At least 2 comparisons between LiDCO and TDCO values were made at each CO rate. The TDCO indicator was 1.5 mL of 5% dextrose at room temperature; with the LiDCO technique, each cat received 0.005 mmol of lithium/kg (concentration, 0.015 mmol/mL). Serum lithium concentrations were measured prior to the first and following the last CO determination.

Results—35 of 47 recorded comparisons were analyzed; via linear regression analysis (LiDCO vs TDCO values), the coefficient of determination was 0.91. The mean bias (TDCO-LiDCO) was –4 mL/kg/min (limits of agreement, –35.8 to +27.2 mL/kg/min). The concordance coefficient was 0.94. After the last CO determination, serum lithium concentration was < 0.1 mmol/L in each cat.

Conclusions and Clinical Relevance—Results indicated a strong relationship and good agreement between LiDCO and TDCO values; the LiDCO method appears to be a practical, relatively noninvasive method for measurement of CO in anesthetized cats. (Am J Vet Res2005;66:1639–1645).
In vitro evaluation of canine and feline calcium oxalate urolith fragility via shock wave lithotripsy
Authors: Adams Larry G. , Williams James C. , McAteer James A. , Hatt Erin K. , Lingeman James E. , Osborne Carl A.
Published: December 2005

Objective—To test the hypothesis that feline calcium oxalate uroliths are intrinsically more resistant to comminution via shock wave lithotripsy (SWL) than canine calcium oxalate uroliths through comparison of the fragility of canine and feline uroliths in a quantitative in vitro test system.

Sample Population—Calcium oxalate uroliths (previously obtained from dogs and cats) were matched by size and mineral composition to create 7 pairs of uroliths (1 canine and 1 feline urolith/pair).

Procedure—Uroliths were treated in vitro with 100 shock waves (20 kV; 1 Hz) by use of an electrohydraulic lithotripter. Urolith fragmentation was quantitatively assessed via determination of the percentage increase in projected area (calculated from the digital image area of each urolith before and after SWL).

Results—After SWL, canine uroliths (n = 7) fragmented to produce a mean ± SD increase in image area of 238 ± 104%, whereas feline uroliths (7) underwent significantly less fragmentation (mean image area increase of 78 ± 97%). The post-SWL increase in fragment image area in 4 of 7 feline uroliths was < 50%, whereas it was > 150% in 6 of 7 canine uroliths.

Conclusions and Clinical Relevance—Results indicate that feline calcium oxalate uroliths are less susceptible to fragmentation via SWL than canine calcium oxalate uroliths. In some cats, SWL may not be efficacious for fragmentation of calcium oxalate nephroliths or ureteroliths because the high numbers of shock waves required to adequately fragment the uroliths may cause renal injury. (Am J Vet Res2005;66:1651–1654)
Randomized, controlled study of inhaled fluticasone propionate, oral administration of prednisone, and environmental management of horses with recurrent airway obstruction
Authors: Couëtil Laurent L. , Chilcoat Clayton D. , DeNicola Denis B. , Clark Shawn P. , Glickman Nita W. , Glickman Lawrence T.
Published: December 2005

Objective—To determine whether administration of glucocorticoids provides additional benefits to environmental management of horses with recurrent airway obstruction (RAO).

Animals—28 horses with RAO.

Procedure—Horses were classified as having mild, moderate, or severe RAO. Within each category, horses were randomly assigned to receive inhaled fluticasone propionate, inhaled control substance, or oral administration of prednisone. During the 4- week study, horses were maintained outdoors and fed a pelleted feed. Clinical scores, pulmonary function, results of cytologic examination of bronchoalveolar lavage fluid (BALF), and adrenal gland function were determined before and 2 and 4 weeks after initiation of treatment.

Results—Clinical score and pulmonary function of all RAO-affected horses improved during the treatment period. After 4 weeks, clinical scores and pulmonary function of horses treated with a glucocorticoid were not different from those for the control treatment. In horses with severe RAO, treatment with fluticasone for 2 weeks resulted in significantly greater improvement in pulmonary function, compared with pulmonary function after treatment with prednisone or the control substance. Treatment with a glucocorticoid for 4 weeks and a low-dust environment did not have any effect on cellular content of BALF. Treatment with prednisone for 2 weeks resulted in a significant decrease in serum cortisol concentration, compared with concentrations after administration of fluticasone or the control substance.

Conclusions and Clinical Relevance—Environmental management is the most important factor in the treatment of horses with RAO. Early treatment with inhaled fluticasone can help accelerate recovery of horses with severe RAO. (Am J Vet Res2005;66:1665–1674)
Products resulting from cleavage of the interglobular domain of aggrecan in samples of synovial fluid collected from dogs with early- and late-stage osteoarthritis
Authors: Innes John F. , Little Chris B. , Hughes Clare E. , Caterson Bruce
Published: December 2005

Objective—To investigate interglobular domain (IGD) cleavage of aggrecan in dogs with naturally developing osteoarthritis (OA).

Sample Population—Samples of synovial fluid (SF) obtained from 3 cubital (elbow) joints and 3 stifle joints of 4 clinically normal dogs, 24 elbow joints of 12 dogs with early-stage OA, 8 stifle joints of 5 dogs with early-stage OA, and 10 stifle joints of 9 dogs with latestage OA.

Procedure—Fractions of SF were assayed for total glycosaminoglycan (GAG) content and also subjected to western blot analysis by use of monoclonal antibodies against neoepitopes generated by cleavage of the IGD of the aggrecan protein core by matrix metalloproteinase (MMP; BC-14) and aggrecanase (BC-3).

Results—Total GAG content of SF from joints of clinically normal dogs did not differ from that of dogs with early-stage OA. The GAG content of SF from joints of dogs with late-stage OA was significantly lower, compared with GAG content for other SF samples. Aggrecanase-generated fragments were detected in SF from all groups but not in all samples. Matrix metalloproteinase– generated fragments were not detected in any SF samples. In early-stage OA, high-molecularweight aggrecanase-generated aggrecan catabolites were evident.

Conclusions and Clinical Relevance—GAG content of SF obtained from dogs with late-stage OA is significantly decreased, suggesting proteoglycan depletion of cartilage. Aggrecanases, but not MMPs, are the major proteolytic enzymes responsible for IGD cleavage of aggrecan in canine joints. Analyses of SF samples to detect aggrecanase-generated catabolites may provide an early biomarker for discriminating early- and latestage OA in dogs. (Am J Vet Res2005;66:1679–1685)
Development of a physiologic-based pharmacokinetic model for estimating sulfamethazine concentrations in swine and application to prediction of violative residues in edible tissues
Authors: Buur Jennifer L. , Baynes Ronald E. , Craigmill Arthur L. , Riviere Jim E.
Published: December 2005

Objective—To develop a flow-limited, physiologicbased pharmacokinetic model for use in estimating concentrations of sulfamethazine after IV administration to swine.

Sample Population—4 published studies provided physiologic values for organ weights, blood flows, clearance, and tissue-to-blood partition coefficients, and 3 published studies provided data on plasma and other tissue compartments for model validation.

Procedure—For the parent compound, the model included compartments for blood, adipose, muscle, liver, and kidney tissue with an extra compartment representing the remaining carcass. Compartments for the N-acetyl metabolite included the liver and the remaining body. The model was created and optimized by use of computer software. Sensitivity analysis was completed to evaluate the importance of each constant on the whole model. The model was validated and used to estimate a withhold interval after an IV injection at a dose of 50 mg/kg. The withhold interval was compared to the interval estimated by the Food Animal Residue Avoidance Databank (FARAD).

Results—Specific tissue correlations for plasma, adipose, muscle, kidney, and liver tissue compartments were 0.93, 0.86, 0.99, 0.94, and 0.98, respectively. The model typically overpredicted concentrations at early time points but had excellent accuracy at later time points. The withhold interval estimated by use of the model was 120 hours, compared with 100 hours estimated by FARAD.

Conclusions and Clinical Relevance—Use of this model enabled accurate prediction of sulfamethazine pharmacokinetics in swine and has applications for food safety and prediction of drug residues in edible tissues. (Am J Vet Res2005;66:1686–1693)
Use of a Bayesian risk-mapping technique to estimate spatial risks for mare reproductive loss syndrome in Kentucky
Authors: Thompson James A. , Brown II Stuart E. , Riddle W. Thomas , Seahorn Janyce C. , Cohen Noah D.
Published: December 2005

Objective—To estimate spatial risks associated with
mare reproductive loss syndrome (MRLS) during
2001 among horses in a specific study population and
partition the herd effects into those attributable to
herd location and those that were spatially random
and likely attributable to herd management.

Animals—Pregnant broodmares from 62 farms in 7
counties in central Kentucky.

Procedure—Veterinarians provided the 2001 abortion
incidence proportions for each farm included in the
study. Farms were georeferenced and data were analyzed
by use of a fully Bayesian risk-mapping technique.

Results—Large farm-to-farm variation in MRLS incidence
proportions was identified. The farm-to-farm
variation was largely attributed to spatial location
rather than to spatially random herd effects

Conclusions and Clinical Relevance—Results indicate
that there are considerable data to support an
ecologic cause and potential ecologic risk factors for
MRLS. Veterinary practitioners with more detailed
knowledge of the ecology in the 7 counties in
Kentucky that were investigated may provide additional
data that would assist in the deduction of the
causal factor of MRLS via informal geographic information
systems analyses and suggest factors for
inclusion in further investigations. (Am J Vet Res 2005;66:17–20)
Evaluation of analgesia resulting from extracorporeal shock wave therapy and radial pressure wave therapy in the limbs of horses and sheep
Authors: McClure Scott R. , Sonea Iona M. , Evans Richard B. , Yaeger Michael J.
Published: December 2005

Objective—To identify the duration and potential
mechanisms of analgesia following extracorporeal
shock wave therapy (ESWT) and radial pressure wave
therapy (RPWT) in limbs of horses and sheep.

Animals—6 horses and 30 sheep.

Procedure—An electrical stimulus was used to identify
the nociceptive threshold for each horse daily for
3 days before treatment (baseline) with ESWT or
RPWT, 8 hours after treatment, and at 24-hour intervals
for 7 days after treatment. Testing was conducted
for the treatment field (midmetacarpus or
midmetatarsus) and nerve field (medial and lateral
forelimb heel bulbs) distal to a treatment site that
included the nerve on the abaxial surface of the proximal
sesamoid bone. All 4 limbs of 30 sheep were
treated with ESWT, RPWT, or a sham treatment. Two
sheep were euthanatized daily and tissue harvested
for histologic evaluation of nerves, and concentrations
of substance P and calcitonin gene-related peptide
were measured in the skin and periosteum.

Results—Values did not differ significantly between
baseline and after treatment for the treatment field or
nerve field sensation. There was a large difference in
the slope when data for horses were plotted for the
first 3 days after treatment, compared with the slope
for days 4 to 7 after treatment. No differences were
found in neuropeptide concentrations after treatment
of the sheep, but there was an inflammatory
response in the treated nerves.

Conclusions and Clinical Relevance—A small cutaneous
analgesic effect may exist at the treatment site
for approximately 3 days after ESWT or RPWT in
horses. (Am J Vet Res 2005;66:1702–1708)
Use of corrosion casting techniques to evaluate coronary collateral vessels and anastomoses in hearts of canine cadavers
Authors: Noestelthaller Arne , Probst Alexander , Koenig Horst E.
Published: December 2005

Objective—To study and investigate branching patterns
of the canine coronary arteries and collateral
circulation by use of corrosion casting techniques.

Sample Population—31 hearts obtained from cadavers
of clinically normal dogs of various ages and
breeds and of either sex.

Procedure—3-dimensional reproduction of coronary
arteries was achieved by postmortem injection and
perfusion with casting materials into the aortic sinus
via the ascending aorta. Perfused hearts were macerated
and carefully irrigated; the air-dried specimens
were examined macroscopically and with a magnifying
headset.

Results—Collateral arteries and inter- and intra-arterial
anastomoses were successfully detected in 8
corrosion cast specimens. In total, 9 coronary collateral
arteries and 3 interarterial anastomoses were
found.

Conclusions and Clinical Relevance—Our finding of
coronary collateral arteries in canine hearts is in
agreement with recent findings in coronary flow
study. On the basis of our results, vasodilation treatment
to improve collateral vessel remodeling in dogs
with myocardial dysfunction may be warranted. (Am J
Vet Res 2005;66:1724–1728)
Effects of osteogenic inducers on cultures of canine mesenchymal stem cells
Authors: Volk Susan W. , Diefenderfer David L. , Christopher Scott A. , Haskins Mark E. , Leboy Phoebe S.
Published: December 2005

Objective—To examine age-related efficacy of bone
morphogenetic protein (BMP)-2, ascorbate, and
dexamethasone as osteogenic inducers in canine
marrow-derived stromal cells (MSCs).

Sample Population—Samples of femoral bone marrow
obtained from 15 skeletally immature (< 1 year
old) and 4 skeletally mature (> 1.5 years old) dogs.

Procedure—First-passage canine MSC cultures were
treated with 100 µg of ascorbate phosphate/mL,
10–7M dexamethasone, 100 ng of BMP-2/mL, or a
combination of these osteoinducers. On day 6, cultures
were harvested for quantitation of alkaline phosphatase
(ALP) activity and isolation of RNA to prepare
cDNA for real-time polymerase chain reaction analyses
of osteoblast markers.

Results—Early markers of osteogenesis were
induced in canine MSCs by BMP-2 but not dexamethasone.
In young dogs, the combination of BMP-
2 and ascorbate yielded the highest ALP mRNA concentrations
and activity. This combination also
induced significant increases in mRNA for osteopontin
and runt-domain transcription factor 2. In comparison
to MSCs from immature dogs, those from
mature dogs had diminished ALP activity in response
to BMP and ascorbate. Results for cultures treated
with 3,4-dehydroproline suggested that ascorbateinduced
production of extracellular matrix was important
for maximal BMP-2 response in canine MSCs.

Conclusions and Clinical Relevance—BMP-2 was
capable of inducing markers of osteogenesis in shortterm
cultures of canine MSCs. In MSCs obtained
from skeletally immature dogs, ascorbate was
required for maximal effects of BMP. These results
define optimal conditions for stem cell osteogenesis
in dogs and will facilitate development of stem
cell–based treatments for dogs with fractures. (Am J
Vet Res 2005;66:1729–1737)
Computed tomography and cross-sectional anatomy of the brain in clinically normal dogs
Authors: De Rycke Lieve M. , Gielen Ingrid M. , Meervenne Sofie A. Van , Simoens Paul J. , Bree Henri J. van
Published: December 2005

Objective—To provide a detailed anatomic description
of brain structures in clinically normal dogs by
means of computed tomography (CT).

Animals—4 clinically normal adult German Shepherd
Dogs weighing 30 to 35 kg.

Procedure—Each dog was anesthetized and positioned
in ventral recumbency for CT examination of
the brain; transverse scans were completed at 2-mm
intervals from the cribriform plate of the ethmoid
bone to the cranial part of the atlas by use of a thirdgeneration
CT scanner. Contrast material was injected
IV, and a second series of scans was completed.
Images (with or without contrast) from all dogs were
reviewed by use of a soft tissue setting (window
width, 150 Hounsfield units; window level, 50
Hounsfield units). One of the dogs was euthanatized,
and a 3.5% formaldehyde solution was perfused via
the common carotid arteries. After fixation, the brain
was embedded in gelatin and sectioned into 5-mm thick
transverse sections by use of a stainless-steel
knife. Anatomic sections were photographed and
compared with the corresponding CT views.

Results—Most features of the brain that were identified
on anatomic sections could be identified on the
corresponding CT scans despite the low contrast
between structures, particularly if adjacent bony and
soft tissue structures were used as landmarks.
Additional anatomic structures surrounding the brain
were also identifiable on the CT images.

Conclusions and Clinical Relevance—Images
obtained in this study could be used as a guide for
evaluation of CT images of the brain in dogs with
brain diseases. (Am J Vet Res 2005;66;1743–1756)
Evaluation of the concentration of marbofloxacin in alveolar macrophages and pulmonary epithelial lining fluid after administration in dogs
Authors: Boothe Harry W. , Jones Sarah A. , Wilkie W. Scott , Boeckh Albert , Stenstrom Kristol K. , Boothe Dawn M.
Published: December 2005

Objective—To determine concentrations of marbofloxacin
in alveolar macrophages (AMs) and epithelial
lining fluid (ELF) and compare those concentrations
with plasma concentrations in healthy dogs.

Animals—12 adult mixed-breed and purebred
hounds.

Procedure—10 dogs received orally administered marbofloxacin
at a dosage of 2.75 mg/kg every 24 hours for
5 days. Two dogs served as nontreated controls.
Fiberoptic bronchoscopy and bronchoalveolar lavage
procedures were performed while dogs were anesthetized
with propofol, approximately 6 hours after the
fifth dose. The concentrations of marbofloxacin in plasma
and bronchoalveolar fluid (cell and supernatant fractions)
were determined by use of high-performance liquid
chromatography with detection of fluorescence.

Results—Mean ± SD plasma marbofloxacin concentrations
2 and 6 hours after the fifth dose were 2.36 ±
0.52 µg/mL and 1.81 ± 0.21 µg/mL, respectively.
Mean ± SD marbofloxacin concentration 6 hours after
the fifth dose in AMs (37.43 ± 24.61 µg/mL) was significantly
greater than that in plasma (1.81 ± 0.21
µg/mL) and ELF (0.82 ± 0.34 µg/mL), resulting in a
mean AM concentration-to-plasma concentration
ratio of 20.4, a mean AM:ELF ratio of 60.8, and a
mean ELF-to-plasma ratio of 0.46. Marbofloxacin was
not detected in any samples from control dogs.

Conclusions and Clinical Relevance—Marbofloxacin
concentrations in AMs were greater than the mean
inhibitory concentrations of major bacterial pathogens
in dogs. Results indicated that marbofloxacin accumulates
in AMs at concentrations exceeding those
reached in plasma and ELF. The accumulation of marbofloxacin
in AMs may facilitate treatment for susceptible
intracellular pathogens or infections associated
with pulmonary macrophage infiltration. (Am J Vet Res
2005;66:1770–1774)
Evaluation of intra- and interobserver reliability and image reproducibility to assess usefulness of high-resolution ultrasonography for measurement of anterior segment structures of canine eyes
Authors: Bentley Ellison , Miller Paul E. , Diehl Kathryn A.
Published: December 2005

Objective—To evaluate the usefulness of high-resolution ultrasonography (HRUS) for measurements of anterior segment structures in canine eyes.

Animals—4 clinically normal Beagles.

Procedure—Images were obtained from 8 eyes with a handheld 20-MHz transducer. Eleven anterior segment structures on each image were measured 5 times by 2 independent observers. Coefficients of variation (CVs) for measurements were used to assess intraobserver reliability. Interobserver reliability was assessed by comparing measurements obtained by the 2 observers from the same images. Five images were sequentially obtained from 2 locations (ie, superior and temporal) to evaluate image reproducibility. Anterior segment structures were measured once on each image; image reproducibility was assessed by use of the CV for each parameter measured. Imaging location was assessed by comparison of CV for measurements from each location.

Results—CVs were < 10% for observer A for all measurements except the ciliary cleft area (11.63%). The CVs were > 10% for observer B for measurements of the angle recess area (18.51%) and ciliary cleft width (17.44%) and area (16.01%). Significant differences in measurements between observers were found for 5 of 11 anterior segment structures. Imaging the superior aspect of the globe provided the most reproducible images, although image reproducibility was still somewhat variable, with the highest and lowest CVs for measurements of 33.01% and 11.32%, respectively, in the superior position.

Conclusions and Clinical Relevance—High-resolution ultrasound images can be used to reliably measure various anterior segment structures. Clinically relevant findings in the anterior segment of canine eyes may be detectable by use of HRUS. (Am J Vet Res2005;66:1775–1779)