bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal interaction of serum vitamin D concentration and bone density in alpacas
Authors: Parker Jill E. , Timm Karen I. , Smith Bradford B. , Van Saun Robert J. , Winters Kerri M. , Sukon Peerapol , Snow Christine M.
Published: January 2006

Objective—To evaluate temporal changes in bone mineral density associated with seasonal variation in serum vitamin D, calcium, and phosphorus concentrations in alpacas.

Animals—5 healthy mature neutered male alpacas.

Procedure—Metacarpal bone mineral density was measured at 4 times during a year. Each time alpacas were weighed, blood was collected for determination of serum calcium, phosphorus, and vitamin D concentrations, and samples of feed were analyzed for nutrient content. Vitamin D status was determined by use of an assay that measured serum 25-hydroxycalciferol concentration. Effects of changes in serum vitamin D, calcium, and phosphorus concentration and body weight with season on bone mineral density were determined.

Results—Bone mineral density, body weight, and serum vitamin D and phosphorus concentrations varied with season. Bone mineral density, serum vitamin D concentration, and body weight also varied among individual alpacas. Serum vitamin D concentration was lower in January than the previous October and increased from May to the following September. The decrease in bone mineral density lagged behind the decrease in serum vitamin D concentration and was lower in May, compared with the previous October. Body weight was lower in May than the previous October or following September. Solar radiation was highest in July and lowest in December.

Conclusions and Clinical Relevance—Seasonal changes in bone mineral density are associated with changes in serum vitamin D concentrations in alpacas. Changes in bone mineral density associated with a decline in serum vitamin D concentration may predispose some alpacas to developing fractures minimal trauma. (Am J Vet Res2002; 63:948–953)
Effects on functions of ovine blood mononuclear cells for each of several fatty acids at concentrations found in plasma of healthy and ketotic ewes
Authors: Lacetera Nicola , Franci Ombretta , Scalia Daniela , Bernabucci Umberto , Ronchi Bruno , Nardone Alessandro
Published: January 2006

Objective—To assess effects on functions of peripheral blood mononuclear cells (PBMC) obtained from ewes for each of several fatty acids represented in ovine plasma at concentrations mimicking those of ketotic or healthy ewes.

Sample Population—Blood samples obtained from 6 Sardinian ewes.

Procedure—The PBMC were cultured in media that contained oleic (OA), palmitic (PA), stearic (SA), linoleic (LA), or palmitoleic (POA) acid at concentrations similar to those of ketotic or healthy ewes. Synthesis of DNA was stimulated by use of concanavalin A or pokeweed mitogen (PWM). Secretion of IgM was stimulated by use of PWM.

Results—High concentrations (900, 450, and 225 µmol/L) of OA significantly inhibited DNA synthesis and IgM secretion of PBMC. Conversely, low concentrations (56 or 28 µmol/L) of OA significantly enhanced DNA synthesis of PBMC. High concentrations of PA (600, 300, 150, 75, 37.5, or 18.7 µmol/L) and SA (300, 150, or 75 µmol/L) significantly inhibited DNA synthesis of PBMC. High concentrations of PA (600, 300, 150, 75, 37.5, or 18.7 µmol/L) and SA (300, 150, 75, or 38 µmol/L) also significantly inhibited IgM secretion of PBMC. None of the concentrations of LA and POA affected PBMC functions.

Conclusion and Clinical Relevance—Impaired immunoresponsiveness of ketotic ewes is likely associated with an increase of plasma concentrations of OA, PA, or SA and not with that of LA or POA. At physiologic concentrations, single fatty acids are likely to participate in modulation of immunoresponsiveness by exerting suppressive or stimulatory effects on immune cells. (Am J Vet Res2002;63:958–962)
Bovine adenovirus serotype 7 infections in postweaning calves
Authors: Fent Genny M. , Fulton Robert W. , Saliki Jeremiah T. , Caseltine Shannon L. , Lehmkuhl Howard D. , Confer Anthony W. , Purdy Charles W. , Briggs Robert E. , Loan Raymond W. , Duff Glenn C.
Published: January 2006

Objective—To detect bovine adenovirus serotype 7 (BAV-7) infections in calves by use of viral isolation and serologic testing.

Animals—205 postweaning calves.

Procedure—121 calves were assembled by an order buyer through auction markets in eastern Tennessee and transported to New Mexico where they were commingled with 84 healthy ranch-reared calves. Tests included viral isolation in cell culture from peripheral blood leukocytes (PBL) and detection of serum BAV-7 antibodies by use of microtitration viral neutralization.

Results—BAV-7 was isolated from PBL of 8 calves and seroconversion to BAV-7 was detected for 38 of 199 (19.1%) calves. Concurrent bovine viral diarrhea virus infections were detected in most calves from which BAV-7 was isolated.

Conclusions and Clinical Relevance—Results of our study indicate that BAV-7 infections can be found in postweaning commingled calves and may develop more commonly in calves with concurrent infections with viruses such as bovine viral diarrhea virus (BVDV). (Am J Vet Res2002;63:976–978).
Oral bioavailability and pharmacokinetic characteristics of ketoprofen enantiomers after oral and intravenous administration in Asian elephants (Elephas maximus)
Authors: Hunter Robert P. , Isaza Ramiro , Koch David E.
Published: January 2006

Objective—To assess oral bioavailability (F) and pharmacokinetic
characteristics of the R- and S-enantiomers
of ketoprofen administered IV and orally to
captive Asian elephants (Elephas maximus).

Animals—5 adult Asian elephants.

Procedure—Elephants received single treatments of
racemic ketoprofen at a dose of 2.2 mg/kg, administered
IV and orally, in a complete crossover design.
Blood samples were collected at intervals during the
24 hours following treatment. At least 4 weeks
elapsed between drug administrations. Samples
were analyzed for R- and S-ketoprofen with a validated
liquid chromatography-mass spectroscopic assay.
Pharmacokinetic parameters were determined by use
of noncompartmental analysis.

Results—The enantiomers of ketoprofen were
absorbed well after oral administration, with median F
of 101% for R-ketoprofen and 85% for S-ketoprofen.
Harmonic mean half-life ranged from 3.8 to 5.5 hours,
depending on route of administration and enantiomer.
The area under the concentration-time curve, mean
residence time, apparent volume of distribution, plasma
clearance, and maximum plasma concentration
values were all significantly different between the 2
enantiomers for both routes of administration.

Conclusion and Clinical Relevance—Ketoprofen
has a long terminal half-life and complete absorption
in this species. Based on the pharmacokinetic data, a
dosage of ketoprofen of 1 mg/kg every 48 hours to 2
mg/kg every 24 hours, PO or IV, is recommended for
use in Asian elephants, although the safety and efficacy
of ketoprofen during long-term administration in
elephants have not been determined. (Am J Vet Res
2003;64:109–114)
Evaluation of erythropoiesis and changes in serum erythropoietin concentration in cats after renal transplantation
Authors: Aronson Lillian R. , Preston Alicia , Bhalerao Dilip P. , Drobatz Kenneth J. , Giger Urs
Published: January 2006

Objective—To investigate the clinicopathologic patterns of the erythropoietic response after renal transplantation in cats with chronic renal failure (CRF).

Animals—14 cats with CRF undergoing renal transplantation.

Procedure—Before and at intervals during a 6-month period after transplantation, serum creatinine and erythropoietin concentrations, Hct, erythrocyte indices, aggregate reticulocyte percentage, and iron variables were measured. Additionally, the number of transfusions administered to and any complications that developed in each cat were recorded.

Results—In all cats, preoperative azotemia resolved within 6 days after renal transplantation. Two cats had a temporary increase in serum creatinine concentration secondary to an acute graft rejection episode. Anemia (defined as Hct < 28%) resolved in 10 cats 3 to 49 days after surgery. Resolution of anemia was delayed in 2 cats that had acute rejection episodes. Serum erythropoietin concentration and reticulocyte percentage were low preoperatively; values after surgery were highly variable. Compared with preoperative values, serum erythropoietin concentration increased 1 to 4 days after surgery in 11 cats; between days 5 and 58, another increase was detected in 9 cats. Serum iron concentrations were generally low before and 14 days after transplantation.

Conclusion and Clinical Relevance—The erythropoietic response was highly variable in cats after renal transplantation, but anemia typically resolved within 1 month after surgery. A delay in resolution of anemia in cats may indicate poor graft function and inadequate iron stores, suggesting the need for further evaluation for concurrent illness. (Am J Vet Res2003;64: 1248–1254)
In vitro evaluation of the distribution of blood flow within a canine bipedicled latissimus dorsi muscle flap
Authors: Monnet Eric , Rooney Matthew B. , Chachques Juan C.
Published: January 2006

Objective—To identify the predominant perforating
artery in the canine latissimus dorsi muscle and
demonstrate that perfusion of the predominant perforating
artery improves blood flow in segments of the
latissimus dorsi muscle that are located distally from
the thoracodorsal artery.

Sample Population—Latissimus dorsi muscles dissected
from 7 dogs.

Procedures—Colored microspheres were used to
determine the degree of perfusion of the latissimus
dorsi muscle via the thoracodorsal artery,
predominant perforating artery, or the thoracodorsal
artery and predominant perforating artery
together. The latissimus dorsi muscle was divided
into 4 proximal to distal segments relative to the
thoracodorsal artery (segments A, B, C, and D,
respectively).

Results—The perforating artery, located at the level
of the fifth intercostal space, predominantly supplied
perfusion to segments B, C, and D. The number of
microspheres received by segment C was significantly
higher when the thoracodorsal artery and perforating
artery were used for muscle perfusion (181.40 ±
44.90 microspheres/300 g of tissue for every 3,000
spheres injected), compared with use of the thoracodorsal
artery alone (60.00 ± 13.70 microspheres/300 g of tissue for every 3,000 spheres
injected).

Conclusions and Clinical Relevance—Blood flow
via the predominant perforating artery improves perfusion
to the middle part of the latissimus dorsi muscle
in dogs. A bipedicled latissimus dorsi muscle flap
would provide a healthier muscle for cardiac assist in
the treatment of dilated cardiomyopathy in dogs.
(Am J Vet Res 2003;64:1255–1259)
Evaluation of progesterone and estrogen receptor expression in 15 meningiomas of dogs and cats
Authors: Adamo P. Filippo , Cantile Carlo , Steinberg Howard
Published: January 2006

Objective—To evaluate progesterone and estrogen receptor expression in meningiomas of the CNS in dogs and cats.

Animals—8 dogs (1 of which was treated with gestrinone) and 5 cats with intracranial meningiomas and 2 dogs with spinal cord meningiomas; tissue samples were also obtained from 1 clinically normal dog and 1 clinically normal cat.

Procedure—Meningioma tissue was obtained during surgery or at necropsy; samples were processed for histologic classification and immunohistochemical evaluation of the proportion of tumor cells with progesterone and estrogen receptors. Correlation among receptor expression, tumor grade, and histologic subtypes was determined.

Results—Several histologic subtypes of intracranial meningiomas were detected among tissue samples. In the cats, all intracranial meningiomas were benign. Progesterone receptor immunoreactivity was detected in 14 of 15 meningiomas. Progesterone receptor expression was identified in > 80% of cells in 8 intracranial meningiomas (4 dogs and 4 cats) and 2 spinal cord meningiomas. In samples of malignant transitional and granular cell meningiomas in dogs, progesterone receptors were detected in 32 and 4.8% of cells respectively. In 1 cat, 38% of tumor cells had progesterone receptors. In a dog treated with gestrinone, no progesterone receptors were detected in the intracranial meningioma. Estrogen receptors were only detected in the tumor of 1 dog.

Conclusions and Clinical Relevance—Results indicate a high proportion of progesterone receptors in cells of meningiomas of the CNS in dogs and cats. Antiprogesterone treatment may have a role in the treatment of unresectable or recurrent meningiomas in dogs and cats. (Am J Vet Res2003;64:1310–1318)
Epidemiologic characteristics and management of polysaccharide storage myopathy in Quarter Horses
Authors: Firshman Anna M. , Valberg Stephanie J. , Bender Jeffrey B. , Finno Carrie J.
Published: January 2006

Objective—To characterize onset and clinical signs of polysaccharide storage myopathy (PSSM) in a welldefined population of affected Quarter Horses, identify risk factors for PSSM, determine compliance of owners to dietary and exercise recommendations, and evaluate the efficacy of dietary and exercise recommendations.

Animals—40 Quarter Horses with PSSM and 37 unaffected control horses.

Procedures—Owners of horses with PSSM completed a retrospective questionnaire concerning their horse's condition.

Results—Between horses with PSSM and control horses, no significant differences were found in sex distribution (21 vs 15 females and 16 vs 22 males, respectively), temperament, muscle build, diet, or amount of turnout. In horses with PSSM, signs of muscle stiffness, muscle fasciculations, sweating, exercise intolerance, weakness, muscle wasting, reluctance to move, colic, abnormal gait, recumbency, lameness, and swollen muscles began between the age of 1 day and 14 years (mean age, 4.9 ± 3.5 years). Five horses with PSSM developed acute muscle atrophy. Sixty-three percent (25/40) of owners fed the recommended diet, 55% (22/40) provided regular exercise, and 40% (16/40) followed both dietary and exercise recommendations. Owners of affected horses for which a decrease in severity or frequency of PSSM was not found did not follow the exercise, dietary, or both recommendations. All horses for which both dietary and exercise recommendations were followed had improvement in signs of PSSM.

Conclusions and Clinical Relevance—In addition to exertional rhabdomyolysis, signs of PSSM include acute muscle atrophy and gait abnormalities. It appears that PSSM can be managed by following dietary recommendations combined with gradual increases in daily exercise. (Am J Vet Res2003; 64:1319–1327)
Assessment of the accuracy of computed tomography for measurement of normal equine pituitary glands
Authors: McKlveen Tori L. , Jones Jeryl C. , Sponenberg D. Phillip , Scarratt Kent , Ward Daniel L. , Aardema Charles H.
Published: January 2006

Objective—To describe the anatomic features of the pituitary gland region in horses via computed tomography (CT) and determine the accuracy of CT for estimating normal equine pituitary gland dimensions.

Animals—25 adult horses with no clinical signs of pituitary disease.

Procedure—Transverse CT images and gross transverse tissue sections were compared in 2 horses. Contrast-enhanced CT of the pituitary gland region was performed postmortem in 23 horses with 4 slice thickness and interval settings (10-mm contiguous or overlapping slices and 4-mm contiguous or overlapping slices). Gross and CT estimates of pituitary gland dimensions were compared via ANOVA. Accuracy of CT estimates was calculated with gross pituitary gland measurements as the known value.

Results—Pituitary glands were located between the temporomandibular joints and had contrast enhancement. Mean gross dimensions were length, 2.11 cm; width, 2.16 cm; height, 0.98 cm; and volume, 2.66 cm3. Gross measurements and CT estimates of pituitary gland length from 10-mm contiguous and overlapping slices did not differ. Gross measurements and CT estimates of pituitary gland width from 4-mm contiguous and overlapping slices did not differ. Estimates of height and volume from all CT techniques differed from gross measurements. Accuracies for CT estimates were length, 88 to 99%; width, 81 to 92%; height, 58 to 71%; and volume, 43 to 55%.

Conclusions and Clinical Relevance—Accuracy of estimates of pituitary gland dimension in horses varied with CT scanning technique; via CT, estimates of length and width of glands were more accurate than estimates of height or volume. (Am J Vet Res2003;64:1387–1394)
Effect of moderate exercise immediately followed by induced hyperglycemia on gene expression and content of the glucose transporter-4 protein in skeletal muscles of horses
Authors: Nout Yvette S. , Hinchcliff Kenneth W. , Jose-Cunilleras Edward , Dearth Lawrence R. , Sivko Gloria S. , DeWille James W.
Published: January 2006

Objective—To determine the effect of a single bout of exercise and increased substrate availability after exercise on gene expression and content of the glucose transporter-4 (GLUT-4) protein in equine skeletal muscle.

Animals—6 healthy adult Thoroughbreds.

Procedure—The study was designed in a balanced, randomized, 3-way crossover fashion. During 2 trials, horses were exercised at 45% of their maximal rate of oxygen consumption for 60 minutes after which 1 group received water (10 mL/kg), and the other group received glucose (2 g/kg, 20% solution) by nasogastric intubation. During 1 trial, horses stood on the treadmill (sham exercise) and then received water (10 mL/kg) by nasogastric intubation. Muscle glycogen concentration and muscle GLUT-4 protein and mRNA content were determined before exercise and at 5 minutes and 4, 8, and 24 hours after exercise.

Results—Although exercise resulted in a 30% reduction in muscle glycogen concentration, no significant difference was detected in muscle GLUT-4 protein or mRNA content before and after exercise. Glycogen replenishment was similar in both exercised groups and was not complete at 24 hours after exercise. Horses that received glucose had significantly higher plasma glucose and insulin concentrations for 3 hours after exercise, but no effect of hyperglycemia was detected on muscle GLUT-4 protein or mRNA content.

Conclusions and Clinical Relevance—Under the conditions of this study, neither exercise nor the combination of exercise followed by hyperglycemia induced translation or transcription of the GLUT-4 protein in horses. (Am J Vet Res2003;64:1401–1408)
Effect of carprofen, etodolac, meloxicam, or butorphanol in dogs with induced acute synovitis
Authors: Borer Luc R. , Peel John E. , Seewald Wolfgang , Schawalder Peter , Spreng David E.
Published: January 2006

Objective—To compare the analgesic and anti-inflammatory effect of single doses of carprofen, etodolac, meloxicam, and butorphanol in dogs with induced acute synovitis (acute pain model) via kinetic gait analysis and orthopedic evaluation and examine measurement of serum C-reactive protein (CRP) concentration as an indicator of treatment efficacy.

Animals—12 Beagles and 6 additional Beagles that were used only in serum CRP analyses.

Procedure—Acute synovitis was induced in right stifle joints of dogs via intra-articular injection of monosodium urate solution. Treatments included butorphanol (0.2 mg/kg, IV), carprofen (4 mg/kg, PO), etodolac (17 mg/kg, PO), or meloxicam (0.2 mg/kg, PO); control dogs received no treatment. The procedure was repeated (3-week intervals) until all dogs received all treatments including control treatment. Lameness was assessed on a biomechanical force platform and via orthopedic evaluations of the stifle joints; blood was collected to monitor serum CRP concentration.

Results—Compared with control dogs, treated dogs had significantly different vertical ground reaction forces and weight-bearing scores. Greatest improvement in lameness was observed in carprofen-treated dogs. Etodolac had the fastest onset of action. Compared with butorphanol treatment, only carprofen and etodolac were associated with significantly lower pain scores. An increase in serum CRP concentration was detected after intra-articular injection in all dogs; this change was similar among groups.

Conclusions and Clinical Relevance—Carprofen, etodolac, and meloxicam had greater efficacy than butorphanol in relief of acute pain. Carprofen was most effective overall. In this acute pain model, serum CRP analysis was not useful to assess drug efficacy. (Am J Vet Res2003;64:1429–1437)
Concentrations of cysteinyl leukotrienes in urine and bronchoalveolar lavage fluid of cats with experimentally induced asthma
Authors: Norris Carol R. , Decile Kendra C. , Berghaus Londa J. , Berghaus Roy D. , Walby William F. , Schelegle Edward S. , Hyde Dallas M. , Gershwin Laurel J.
Published: January 2006

Objective—To evaluate changes in cysteinyl leukotriene (LT) concentrations in urine and bronchoalveolar lavage fluid (BALF) in cats with experimentally induced asthma.

Animals—19 cats with experimentally induced asthma and 5 control cats.

Procedure—Cats were sensitized to Bermuda grass or house dust mite allergen, and phenotypic features of asthma were confirmed with intradermal skin testing, evaluation of BALF eosinophil percentages, and pulmonary function testing. A competitive ELISA kit for LTC4, LTD4, and LTE4 was used for quantitative analysis of LTs. Urinary creatinine concentrations and BALF total protein (TP) concentrations were measured, and urinary LT-to-creatinine ratios and BALF LTto- TP ratios were calculated.

Results—Mean urinary LT-to-creatinine ratios did not differ significantly between control cats and allergensensitized cats before or after sensitization and challenge exposure with saline (0.9% NaCl) solution or allergen, respectively. In BALF, the mean LT-to-TP ratio of control cats did not differ significantly before or after sensitization and challenge exposure with saline. Asthmatic cats had BALF LT-to-TP ratios that were significantly lower than control cats at all time points, whereas ratios for asthmatic cats did not differ significantly among the various time points.

Conclusions and Clinical Relevance—Although LTs were readily detectable in urine, no significant increases in urinary LT concentrations were detected after challenge in allergen-sensitized cats. Spot testing of urinary LT concentrations appears to have no clinical benefit for use in monitoring the inflammatory asthmatic state in cats. The possibility that cysteinyl LTs bind effectively to their target receptors in BALF and, thus, decrease free LT concentrations deserves further study. (Am J Vet Res2003;64:1449–1453)
Interactions of morphine and isoflurane in horses
Authors: Steffey Eugene P. , Eisele John H. , Baggot J. Desmond
Published: January 2006

Objective—To quantitate dose- and time-related magnitudes of interactive effects of morphine (MOR) and isoflurane (ISO) in horses and to characterize pharmacokinetics of MOR in plasma and the ventilatory response to MOR during administration of ISO.

Animals—6 adult horses.

Procedure—Horses were anesthetized 3 times to determine the minimum alveolar concentration (MAC) of ISO in O2and then to characterize the change in anesthetic requirement as defined by the alteration in ISO MAC following IV administration of saline (0.9% NaCl) solution and 2 doses of MOR (low dose, 0.25 mg/kg; high dose, 2.0 mg/kg). Arterial blood samples were obtained before and after MOR and analyzed.

Results—Mean ± SD baseline ISO MAC was 1.43 ± 0.06%. The ISO MAC did not change with time after administration of saline solution. Effects of MOR on ISO MAC varied. Maximal change in MAC ranged from –20.2 to +28.3% and –18.9 to +56.2% after low and high doses of MOR, respectively. Typical half-life of MOR in plasma was 40 to 60 minutes and related to dose. Mean PaCO2increased from 70 mm Hg before MOR to 88 to 102 mm Hg for 30 to 240 minutes after the high dose of MOR. Recovery from anesthesia after administration of the high dose of MOR was considered undesirable and dangerous.

Conclusions and Clinical Relevance—Our results do not support routine clinical use of MOR administered IV at dosages of 0.25 or 2.0 mg/kg as an adjuvant to anesthesia in horses administered ISO. (Am J Vet Res2003;64:166–175)
Pharmacokinetics and tissue concentrations of azithromycin in ball pythons ( Python regius )
Authors: Coke Rob L. , Hunter Robert P. , Isaza Ramiro , Koch David E. , Goatley Marie A. , Carpenter James W.
Published: January 2006

Objective—To determine pharmacokinetics and tissue
concentrations of azithromycin in ball pythons
( Python regius ) after IV or oral administration of a single
dose.

Animals—2 male and 5 female ball pythons.

Procedures—Using a crossover design, each snake
was given a single dose of azithromycin (10 mg/kg) IV.
After a 4-week washout period, each snake was given
a single dose of azithromycin (10 mg/kg) orally. Blood
samples were collected prior to dose administration
and 1, 3, 6, 12, 24, 48, 72, and 96 hours after
azithromycin administration. Azithromycin was quantitated
by use of liquid chromatography-mass spectrometry.

Results—After IV administration, azithromycin had an
apparent volume of distribution of 5.69 L/kg and a
plasma clearance of 0.19 L/h/kg. Harmonic means for
the terminal half-life were 17 hours following IV
administration and 51 hours following oral administration.
Mean residence times were 37 and 94 hours following
IV and oral administration, respectively.
Following oral administration, azithromycin had a peak
plasma concentration (Cmax) of 1.04 µg/mL, a time to
Cmax of 8.4 hours, and a prolonged mean absorption
time of 57 hours. Mean oral bioavailability was 77%.
Tissue concentrations ranged from 4 to 140 times the
corresponding plasma concentration at 24 and 72
hours after azithromycin administration.

Conclusions and Clinical Relevance—Azithromycin
is well absorbed and tolerated by ball pythons. On the
basis of plasma pharmacokinetics and tissue concentration
data, we suggest an azithromycin dosage in
ball pythons of 10 mg/kg, orally, every 2 to 7 days,
depending upon the site of infection and susceptibil
ity of the infective organism. (Am J Vet Res 2003;64:225–228)
Effect of aerosolized albuterol sulfate on resting energy expenditure determined by use of open-flow indirect calorimetry in horses with recurrent airway obstruction
Authors: Mazan Melissa R. , Hoffman Andrew M. , Kuehn Heike , Deveney Edward F.
Published: January 2006

Objective—To evaluate effects of sedation on stability of resistance of the respiratory system (RRS) and measures of resting energy expenditure (REE) by use of open-flow indirect calorimetry (IC) and treatment with aerosolized albuterol on REE in horses with recurrent airway obstruction (RAO).

Animals—9 clinically normal horses and 8 horses with RAO.

Procedure—In phase 1, RRS was measured by using forced oscillometry (FOT) in 5 clinically normal horses before and after sedation with xylazine. In phase 2, REE was measured in 4 clinically normal horses between 20 and 25 minutes and again 35 to 40 minutes after sedation with xylazine. In phase 3, IC was performed between 20 and 25 minutes and FOT was performed between 30 and 35 minutes after xylazine administration in 8 horses with RAO; after administration of 450 µg of albuterol, IC and FOT were repeated.

Results—In phase 1, RRS values were significantly lower 5 and 10 minutes after sedation. In phase 2, diminishing sedation did not significantly affect REE. In phase 3, there was a significant decrease in mean RRS (1.15 ± 0.25 vs 0.84 ± 0.14 cm H20/L/s) and REE (30.68 ± 17.89 vs 27.46 ± 16.54 kcal/kg/d) after albuterol administration.

Conclusions and Clinical Relevance—FOT and IC are useful in obtaining repeatable measurements of RRS and REE, respectively, in sedated horses. Concurrent bronchodilation and decreased REE after albuterol administration suggest that increased work of breathing as a result of airway obstruction may contribute to increased energy demands in horses with RAO. (Am J Vet Res2003;64:235–242)
Hemodynamic effects of nitrous oxide in isoflurane-anesthetized cats
Authors: Pypendop Bruno H. , Ilkiw Jan E. , Imai Ayako , Bolich Jennifer A.
Published: January 2006

Objective—To determine the hemodynamic effects of nitrous oxide in isoflurane-anesthetized cats.

Animals—12 healthy adult domestic shorthair cats.

Procedure—Cats were anesthetized by administration of isoflurane in oxygen. After instruments were inserted, end-tidal isoflurane concentration was set at 1.25 times the individual minimum alveolar concentration, and nitrous oxide was administered in a Latinsquare design at 0, 30, 50, and 70%. Each concentration was administered for 25 minutes before measurements were obtained to allow for stabilization. Heart rate; systemic and pulmonary arterial pressures; central venous pressure; pulmonary artery occlusion pressure; cardiac output; body temperature; arterial and mixed-venous pH, PCO2, PO2, and hemoglobin concentrations; PCV; and total protein and lactate concentrations were measured before and during noxious stimulation for each nitrous oxide concentration. Arterial and mixed-venous bicarbonate concentrations and oxygen saturation, cardiac index, stroke index, rate-pressure product, systemic and pulmonary vascular resistance indices, left and right ventricular stroke work indices, arterial and mixed-venous oxygen contents, oxygen delivery, oxygen consumption, oxygen extraction ratio, alveolar-to-arterial oxygen difference, and venous admixture were calculated.

Results—Arterial pressure, central venous pressure, pulmonary arterial pressure, rate-pressure product, systemic and pulmonary vascular resistance indices, arterial PCO2, and PCV increased during administration of 70% nitrous oxide. Arterial and mixed-venous pH, mixed-venous PO2, and alveolar-to-arterial oxygen difference decreased during administration of 70% nitrous oxide. Results before and during noxious stimulation were similar.

Conclusions and Clinical Relevance—Administration of 70% nitrous oxide to isoflurane-anesthetized cats resulted in improved arterial pressure, which was related to a vasoconstrictive effect. (Am J Vet Res2003;64:273–278)
Use of volumetric capnography to identify pulmonary dysfunction in horses with and without clinically apparent recurrent airway obstruction
Authors: Herholz Conny P. , Gerber Vinzenz , Tschudi Peter , Straub Reto , Imhof Andrea , Busato André
Published: January 2006

Objective—To investigate whether volumetric
capnography indices could be used to differentiate
between horses without recurrent airway obstruction
(RAO) and horses with RAO that were in clinical
remission or that had clinically apparent RAO.

Animals—70 adult Swiss Warmblood horses (20
used for pleasure riding and 50 used for dressage or
show jumping).

Procedure—Horses were allocated to 4 groups on
the basis of history, clinical signs, results of
endoscopy, and cytologic findings (group 1, 21
healthy horses; group 2, 22 horses with RAO that
were in remission; group 3, 16 horses with mild RAO;
group 4, 11 horses with exacerbated RAO). Expiratory
volume and CO2 curves were recorded by use of a
computerized ultrasonic spirometer. Volumetric
capnograms were plotted, and derived indices were
calculated.

Results—Dead-space volume (VD) was calculated by
use of the Bohr equation (VDBohr) and for physiologic
VD (VDphys). Ratios for VDBohr to expiratory tidal volume
(VT) and VDphys to VT as well as an index of effective
CO2 elimination were significantly different among
groups of horses. Age and use of the horses also significantly
affected volumetric capnography indices.

Conclusions and Clinical Relevance—Ratios of
VDBohr to VT and VDphys to VT as well as an index of
effective CO2 elimination were sufficiently sensitive
measures to distinguish between healthy horses and
horses with RAO in remission. To optimize the ability
of volumetric capnography indices to differentiate
among horses in heterogeneous populations, it is
important to account for effects of age and specific
use of the horses. (Am J Vet Res 2003;64:338–345)
Microvascular anatomy of the third compartment of the stomach of llamas
Authors: Hoogmoed Linda M. Van , Harmon Faye A. , Snyder Jack
Published: January 2006

Objective—To characterize the vascular anatomy of the third compartment of the stomach of llamas.

Animals—7 adult llamas.

Procedure—Immediately after each llama was euthanatized, vascular replicas of tissue from the third compartment were prepared by use of methylmethacrylate monomer and catalyst. Following chemical removal of tissue, the casts were further prepared for examination via scanning electron microscopy. By use of barium solution, microangiography was also performed on fixed tissue samples; the infused tissue was sectioned and imaged radiographically. Tissue samples were also collected for histologic evaluation after fixation and H&E staining.

Results—The third compartment was supplied by 4 pairs of primary arteries and veins located around the circumference of the structure. From these vessels, smaller arteries and veins branched to supply the serosal surface and penetrated deeper through the tunica muscularis to supply the submucosal and mucosal layers. An extensive capillary network was arranged in a hexagonal array surrounding the gastric glands, such that the mucosal aspect of the replicas had a honeycomb-like appearance. Histologically, variably sized villous projections lined by a single layer of epithelial cells with an extensive glandular network were observed.

Conclusions and Clinical Relevance—The third compartment of the stomach of llamas is a highly vascular structure with an extensive anastomotic capillary network at the luminal surface. Branching vessels provide extensive collateral circulation, and it appears that surgical incisions should heal well. Incisions in the third compartment should be oriented parallel to the longitudinal plane. (Am J Vet Res2003; 64:346–350)
Efficacy of oral supplementation with L-lysine in cats latently infected with feline herpesvirus
Authors: Maggs David J. , Nasisse Mark P. , Kass Philip H.
Published: January 2006

Objective—To examine the effects of orally administered L-lysine on clinical signs of feline herpesvirus type 1 (FHV-1) infection and ocular shedding of FHV-1 in latently infected cats.

Animals—14 young adult, FHV-1-naive cats.

Procedure—Five months after primary conjunctival inoculation with FHV-1, cats were rehoused and assigned to receive 400 mg of L-lysine in food once daily for 30 days or food only. On day 15, all cats received methylprednisolone to induce viral reactivation. Clinical signs of infection were graded, and viral shedding was assessed by a polymerase chain reaction assay throughout our study. Peak and trough plasma amino acid concentrations were assessed on day 30.

Results—Fewer cats and eyes were affected by conjunctivitis, and onset of clinical signs of infection was delayed on average by 7 days in cats receiving L-lysine, compared with cats in the control group; however, significant differences between groups were not demonstrated. Significantly fewer viral shedding episodes were identified in the treatment group cats, compared with the control group cats, after rehousing but not following corticosteroidinduced viral reactivation. Mean plasma L-lysine concentration was significantly increased at 3 hours but not at 24 hours after L-lysine administration. Plasma arginine concentration was not significantly altered.

Conclusion and Clinical Relevance—Once daily oral administration of 400 mg of L-lysine to cats latently infected with FHV-1 was associated with reduced viral shedding following changes in housing and husbandry but not following corticosteroid administration. This dose caused a significant but short-term increase in plasma L-lysine concentration without altering plasma arginine concentration or inducing adverse clinical effects. (Am J Vet Res2003;64:37–42)
Neutrophil function and plasma opsonic capacity in colostrum-fed and colostrum-deprived neonatal kittens
Authors: Hanel Rita M. , Crawford P. Cynda , Hernandez Jorge , Benson Neal A. , Levy Julie K.
Published: January 2006

Objective—To determine whether passive transfer of IgG in neonatal kittens affects plasma opsonic capacity and neutrophil phagocytic and oxidative burst responses to bacteria in vitro.

Animals—22 kittens from 6 specific pathogen-free queens.

Procedure—Kittens were randomized at birth into the following treatment groups: colostrum-fed, colostrum-deprived, or colostrum-deprived supplemented with feline or equine IgG. Blood samples were collected at intervals from birth to 56 days of age. Plasma IgG concentrations were determined by radial immunodiffusion assay. Neutrophil function was assessed by a flow cytometry assay providing simultaneous measurement of bacteria-induced phagocytosis and oxidative burst. The opsonic capacity of kitten plasma was determined in an opsonophagocytosis assay with bacteria incubated in untreated or heat-inactivated plasma.

Results—Among treatment groups, there were no significant differences in neutrophil phagocytic and oxidative burst responses to bacteria or opsonic capacity of plasma. In all samples of plasma, inactivation of complement and other heat-labile opsonins significantly reduced the opsonic capacity. Plasma IgG concentrations in kittens did not correlate with neutrophil function or plasma opsonic capacity before or after inactivation of complement.

Conclusions and Clinical Relevance—The plasma opsonic capacity and neutrophil phagocytic and oxidative burst responses in vitro of kittens receiving passive transfer of IgG via colostrum intake or IgG supplementation and those deprived of colostrum were similar. The alternate complement pathway or other heat-labile opsonins may be more important than IgG in bacterial opsonization and phagocytosis. (Am J Vet Res2003;64:538–543)
Effect of passive immunity on the development of a protective immune response against bovine viral diarrhea virus in calves
Authors: Ridpath Julia F. , Neill John D. , Endsley Janet , Roth James A.
Published: January 2006

Objective—To determine whether passively acquired antibodies prevent development of a protective immune response to live virus in calves.

Procedures—18 calves.

Procedure—Calves were caught immediately after birth and tested free of bovine viral diarrhea virus (BVDV) and serum antibodies against BVDV. Within 48 hours, 12 calves were fed colostrum that contained antibodies against BVDV and 6 calves received BVDV antibody free milk replacer. Three milk replacer fed and 6 colostrum fed calves were exposed to virulent BVDV2-1373 at 2 to 5 weeks of life when passively acquired serum antibody titers were high. After serum antibody titers against BVDV had decayed to undetectable concentrations (at 7 to 9 months of age), the 3 remaining milk replacer fed calves, 6 colostrum fed calves previously exposed to BVDV2-1373, and 6 colostrum fed calves that had not been exposed to the virus were inoculated with BVDV2-1373.

Results—Passively acquired antibodies prevented clinical disease in inoculated colostrum fed calves at 2 to 5 weeks of life. Serum antibody titers did not increase in these calves following virus inoculation, and serum antibody titers decayed at the same rate as in noninoculated colostrum fed calves. Inoculated colostrum fed calves were still protected from clinical disease after serum antibody titers had decayed to nondetectable concentrations. Same age colostrum fed calves that had not been previously exposed to the virus were not protected.

Conclusion and Clinical Relevance—A protective immune response was mounted in calves with passive immunity, but was not reflected by serum antibodies titers. This finding has implications for evaluating vaccine efficacy and immune status. (Am J Vet Res2003;64:65–69)
Assessment of corneal thickness, intraocular pressure, optical corneal diameter, and axial globe dimensions in Miniature Horses
Authors: Plummer Caryn E. , Ramsey David T. , Hauptman Joe G.
Published: January 2006

Objective—To determine corneal thickness, intraocular pressure (IOP), and horizontal and vertical corneal diameter (HCD and VCD) and to obtain axial measurements of the anterior chamber depth (ACD), crystalline lens thickness (CLT), vitreous chamber depth (VtCD), and axial globe length (AGL) in eyes of Miniature Horses.

Animals—41 healthy Miniature Horses.

Procedure—Ocular component measurements were obtained via ultrasonic pachymetry, applanation tonometry, ultrasound, and by use of a Jameson caliper.

Results—Mean IOP and corneal thickness for all eyes were 26.0 mm Hg and 785.6 µm, respectively. There was no correlation of age with IOP or corneal thickness and no difference in these variables between right and left eyes or between females and males. Mean HCD and VCD were 25.8 and 19.4 mm, respectively; although there were no differences between sexes or between right and left eyes, there was positive correlation of optical corneal diameters with increasing age. Mean ACD, CLT, VtCD, and AGL were smaller in Miniature Horses (5.6, 10.0, 18.1, and 33.7 mm, respectively), compared with values for full-sized horses; there was no difference in these variables between sexes or between right and left eyes in Miniature Horses, but they were correlated with increasing age.

Conclusions and Clinical Relevance—In Miniature Horses, corneal thickness and IOP are similar to values reported for full-sized horses and do not increase with advancing age. Vertical corneal diameter, HCD, and AGL increase until 5, 7, and 2 years of age, respectively. (Am J Vet Res2003;64:661–665).
Influence of glucosamine on matrix metalloproteinase expression and activity in lipopolysaccharide-stimulated equine chondrocytes
Authors: Byron Christopher R. , Orth Michael W. , Venta Patrick J. , Lloyd James W. , Caron John P.
Published: January 2006

Objective—To characterize potential mechanisms of action of glucosamine inhibition of matrix metalloproteinase (MMP) expression and activity in lipopolysaccharide (LPS)-stimulated equine chondrocytes.

Sample Population—Chondrocytes cultured from samples of metacarpophalangeal articular cartilage collected from cadaveric limbs of horses.

Procedure—The effect of glucosamine on MMP activity in conditioned medium from LPS-stimulated cartilage explants was determined by a colorimetric assay with azocoll substrate. Treatments consisted of negative and positive controls, glucose (50mM), and glucosamine (50, 25, 6.25, 3, and 1.5mM). The influence of glucosamine on MMP synthesis was determined in chondrocytes in pellet culture incubated with LPS (20 µg/mL). Concentration of MMP-13 was quantified in spent medium via ELISA; nonspecific MMP activity was determined via azocoll digestion in organomercurial- activated medium. Effects of glucosamine on MMP mRNA concentration in similarly treated chondrocytes were determined by northern blot hybridization with MMP-1, -3, and -13 probes. Statistical analyses were performed with 2-way ANOVA.

Results—Glucosamine had no effect on activated MMP activity but inhibited MMP protein expression, as determined by azocoll digestion (glucosamine, 3 to 50mM) and MMP-13 ELISA (glucosamine, 1.5 to 50mM). Resting mRNA concentrations for MMP-1, -3, and -13 mRNA were significantly lower in cultures exposed to glucosamine at concentrations of 50 and 25mM than those of positive controls.

Conclusions and Clinical Relevance—Glucosamine appears capable of pretranslational, and possibly also translational, regulation of MMP expression; data suggest a potential mechanism of action for chondroprotective effects of this aminomonosaccharide. (Am J Vet Res2003;64:666–671)
Corneal sensitivity in dogs with diabetes mellitus
Authors: Good Kathryn L. , Maggs David J. , Hollingsworth Steven R. , Scagliotti Randall H. , Nelson Richard W.
Published: January 2006

Objective—To compare aesthesiometer-determined corneal sensitivity between diabetic and nondiabetic dogs and to investigate the correlation between corneal sensitivity and duration of diabetes or status of glycemic control, as estimated by use of glycated blood protein concentrations.

Animals—23 diabetic and 29 nondiabetic normoglycemic dogs.

Procedure—A Cochet-Bonnet aesthesiometer was used to measure corneal touch threshold (CTT) in 5 corneal regions of each dog. At the time of ocular examination, duration of diabetes mellitus was estimated from the history, and blood was drawn for assessment of blood glycosylated hemoglobin and serum fructosamine concentrations.

Results—Median CTT for central, nasal, dorsal, temporal, and ventral corneal regions in nondiabetic dogs (1.6, 2.3, 2.8, 2.8, and 5.1 g/mm2, respectively) was significantly lower than in diabetic dogs (2.8, 4.0, 5.1, 5.1, and 6.6 g/mm2, respectively). Median regional CTT in diabetic dogs was not significantly correlated with estimated duration of diabetes mellitus or blood glycated protein concentrations. No significant difference was found in regional CTT between eyes of normoglycemic dogs with unilateral cataracts.

Conclusion and Clinical Relevance—Diabetic dogs have significantly reduced corneal sensitivity in all regions, compared with nondiabetic normoglycemic dogs. Regional variation in corneal sensitivity is similar in diabetic and normoglycemic dogs. Neither glycemic control nor duration of diabetes, as estimated, is significantly correlated with corneal hyposensitivity. Corneal nerve dysfunction may be associated with recurrent or nonhealing ulcers in diabetic dogs for which no other underlying cause can be found. (Am J Vet Res2003;64:7–11)
Evaluation of serum biochemical markers of bone metabolism for early diagnosis of nonunion and infected nonunion fractures in rabbits
Authors: Southwood Louise L. , Frisbie David D. , Kawcak Chris E. , McIlwraith C. Wayne
Published: January 2006

Objective—To evaluate the use of serum concentrations of biochemical markers of bone metabolism (osteocalcin [OC], bone-specific alkaline phosphatase [BS-ALP], and deoxypyridinoline [DPYR]) to compare healing in infected versus noninfected fractures and in fractures with normal repair versus delayed (nonunion) repair in rabbits.

Animals—32 female 9- to 10-month-old New Zealand White rabbits.

Procedure—A femoral fracture defect was made in each rabbit. Rabbits were assigned to the following groups: the bone morphogenetic-2 gene treatment group with either noninfected nonunion or infected (ie, inoculation of defects withStaphylococcus aureus) nonunion fractures or the luciferase (control) gene treatment group with either noninfected nonunion or infected nonunion fractures. Serum samples were obtained before surgery (time 0) and 4, 8, 12, and 16 weeks after surgery. Callus formation and lysis grades were evaluated radiographically at 16 weeks.

Results—Serum OC and BS-ALP concentrations decreased from time 0 at 4 weeks, peaked at 8 weeks, and then decreased. Serum DPYR concentration peaked at 4 weeks and then decreased, independent of gene treatment group or fracture infection status. Compared with rabbits with noninfected fractures, those with infected fractures had lower serum OC and BS-ALP concentrations at 4 weeks, higher serum OC concentrations at 16 weeks, and higher serum DPYR concentrations at 4, 8, and 16 weeks. Combined serum OC, BS-ALP, and DPYR concentrations provided an accuracy of 96% for prediction of fracture infection status at 4 weeks.

Conclusions and Clinical Relevance—Measurement of multiple serum biochemical markers of bone metabolism could be useful for clinical evaluation of fracture healing and early diagnosis of osteomyelitis. (J Am Vet Med Assoc2003;64:727–735)