bluuebunny/crossref_metadata_2025_split huggingface dataset:
Disposition of orally administered cefpodoxime proxetil in foals and adult horses and minimum inhibitory concentration of the drug against common bacterial pathogens of horses
Authors: Carrillo Natalie A. , Giguère Steeve , Gronwall Ronald R. , Brown Murray P. , Merritt Kelly A. , O'Kelley Jeffrey J. 
Published: December 2005

AbstractObjective—To determine the disposition of orally administered cefpodoxime proxetil in foals and adult horses and measure the minimum inhibitory concentrations (MICs) of the drug against common bacterial pathogens of horses.Animals—6 healthy adult horses and 6 healthy foals at 7 to 14 days of age and again at 3 to 4 months of age.Procedure—A single dose of cefpodoxime proxetil oral suspension was administered (10 mg/kg) to each horse by use of a nasogastric tube. In 7- to 14-day-old foals, 5 additional doses were administered intragastrically at 12-hour intervals. The MIC of cefpodoxime for each of 173 bacterial isolates was determined by use of a commercially available test.Results—In 7- to 14-day-old foals, mean ± SD time to peak serum concentration (Tmax) was 1.7 ± 0.7 hours, maximum serum concentration (Cmax) was 0.81 ± 0.22 µg/mL, and elimination half-life (harmonic mean) was 7.2 hours. Disposition of cefpodoxime in 3- to 4-month-old foals was not significantly different from that of neonates. Adult horses had significantly higher Cmaxand significantly lower Tmax, compared with values for foals. The MIC of cefpodoxime required to inhibit growth of 90% of isolates forSalmonella enterica, Escherichia coli, Pasteurellaspp,Klebsiellaspp, and β-hemolytic streptococci was 0.38, 1.00, 0.16, 0.19, and 0.09 µg/mL, respectively.Conclusions and Clinical Relevance—Oral administration at a dosage of 10 mg/kg every 6 to 12 hours would appear appropriate for the treatment of equine neonates with bacterial infections. (Am J Vet Res2005;66:30–35)
Determination of abomasal emptying rate in suckling calves by use of nuclear scintigraphy and acetaminophen absorption
Authors: Marshall Tessa S. , Constable Peter D. , Crochik Sonia S. , Wittek Thomas 
Published: December 2005

AbstractObjective—To develop nuclear scintigraphic and acetaminophen absorption methods for measuring abomasal emptying rate in suckling calves.Animals—9 male Holstein-Friesian calves < 30 days old.Procedure—Calves were fed 2 L of milk replacer, fresh cow's milk, or an isoosmotic (150mM) solution of NaCl, NaHCO3, or sodium acetate containing technetium TC 99m-diethylenetriamine-pentaacetic acid (370 MBq) and acetaminophen (50 mg/kg). Right lateral scintigraphic images and venous blood samples were obtained periodically after feeding. Two power exponential equations were fitted to the scintigraphic data, and 3 pharmacokinetic models were fitted to the acetaminophen concentration–time data.Results—Data from 32 feedings were analyzed, with half emptying time for scintigraphic evaluation ranging from 29 to 202 minutes. Siegel's modified power exponential equation provided a better description of the scintigraphic data than did Elashoff's power exponential equation. The first derivative of Siegel's modified power exponential formula provided the best pharmacokinetic model for the acetaminophen absorption data. Time to maximal acetaminophen concentration (Tmax) provided the most accurate index of abomasal emptying rate from the acetaminophen concentration–time data.Conclusions and Clinical Relevance—Abomasal emptying rate is best determined in healthy suckling calves by use of Siegel's modified power exponential equation to model the scintigraphic data. Pharmacokinetic calculation of Tmax from the acetaminophen absorption curve provides an alternative method for determining abomasal emptying rate in healthy suckling calves that is accurate, inexpensive, practical, and safe. However, it is unclear whether diarrhea would alter the acetaminophen absorption curve in calves. (Am J Vet Res2005;66:364–374)
Assessment of the reliability of plasma electrophoresis in birds
Authors: Rosenthal Karen L. , Johnston Matthew S. , Shofer Frances S. 
Published: December 2005

Abstract

Objective—To determine the reliability of plasma
electrophoresis (EPH) in psittacine birds.

Animals—93 psittacine birds.

Procedure—Jugular venipuncture was performed on
93 awake psittacine birds. The plasma was centrifuged,
separated, aliquoted into duplicate samples,
frozen, and sent to 2 commercial laboratories that
routinely perform avian EPH. Samples from 51 birds
were sent to laboratory A, and samples from 42 birds
were sent to laboratory B. The reliability of EPH
results within each laboratory was assessed, but not
between laboratories. To determine the reliability
(agreement between duplicate samples) of total protein,
albumin, prealbumin, α1-, α2-, β-, and γ-globulin
concentrations, the intraclass correlation coefficient
( ri
) was calculated.

Results—Both laboratories had excellent agreement
between samples for measurement of total protein
concentration and only good agreement for albumin
concentration. Except for the prealbumin concentration
measured at laboratory B, both laboratories had
poor agreement for all other values of the EPH.

Conclusions and Clinical Relevance—These data
indicate that plasma EPH for measuring prealbumin,
α1-, α2-, β-, and γ-globulin concentrations may not be
a reliable tool for assessing avian health. Small
amounts of these proteins in birds plus human variation
in reading the EPH curves may lead to variable
results. Avian veterinarians should cautiously interpret
results from plasma EPH assays for these protein
fractions. (Am J Vet Res 2005;66:375–378)
Expression of equine glucose transporter type 4 in skeletal muscle after glycogen-depleting exercise
Authors: Jose-Cunilleras Eduard , Hayes Kathleen A. , Toribio Ramiro E. , Mathes Lawrence E. , Hinchcliff Kenneth W. 
Published: December 2005

AbstractObjective—To clone and sequence cDNA for equine insulin-responsive glucose transporter (glucose transporter type 4 [GLUT-4]) and determine effects of glycogen-depleting exercise and meal type after exercise on GLUT-4 gene expression in skeletal muscle of horses.Animals—Muscle biopsy specimens from 7 healthy adult horses.Procedure—Total RNA was extracted from specimens, and GLUT-4 cDNA was synthesized and sequenced. Horses were exercised on 3 consecutive days. On the third day of exercise, for 8 hours after exercise, horses were either not fed, fed half of daily energy requirements as hay, or fed an isocaloric amount of corn. The GLUT-4 mRNA was determined by use of realtime reverse transcriptase-polymerase chain reaction in muscle biopsy specimens obtained before 3 consecutive days of exercise and within 10 minutes and 4, 8, and 24 hours after the third exercise bout.Results—A 1,629-bp segment was sequenced, of which 1,530 bp corresponded to the coding region and encoded a protein of 509 amino acids. Expression of GLUT-4 gene increased by 2.3, 4.3, 3.3, and 2.6 times 10 minutes and 4, 8, and 24 hours after exercise, respectively, compared with that prior to exercise. No differences were observed in GLUT-4 gene expression among conditions of feed withholding, corn feeding, and hay feeding during the 8 hours postexercise.Conclusions and Clinical Relevance—Lack of increase of GLUT-4 gene expression after grain feeding and exercise may explain the apparently slower rate of glycogen synthesis after exercise in horses relative to that of other species. (Am J Vet Res2005;66:379–385)
Evaluation of the passive function of the biceps brachii muscle-tendon unit in limitation of shoulder and elbow joint ranges of motion in horses
Authors: Nevens Amy L. , Stover Susan M. , Hawkins David A. 
Published: December 2005

AbstractObjective—To quantify the passive contribution of the biceps brachii muscle-tendon unit to the limits of elbow joint extension during shoulder joint flexion in horses.Sample Population—Normal right forelimb specimens from 6 Thoroughbred cadavers.Procedure—Specimens included the scapula, humerus, radius-ulna, biceps brachii muscle-tendon unit, and stabilizers of the shoulder and elbow joints. Specimens were mounted to a rigid board by transfixation pins through the humerus and instrumented for mechanical manipulation of the limb and joint angle and load measurements. Flexion and extension limits of shoulder and elbow joint ranges of motion were measured in each joint separately, while the other joint was fixed. Measurements were made before and after transection of the biceps brachii muscle- tendon unit.Results—The biceps brachii muscle-tendon unit limited elbow joint extension when the shoulder joint was fixed in flexion, limited shoulder joint flexion when the elbow joint was fixed in extension, and inhibited shoulder joint extension to a lesser degree when the elbow joint was fixed at midrange angles of 75° to 90°.Conclusions and Clinical Relevance—Clinical manipulation of the elbow joint into hyperextension during shoulder joint flexion is indicative of biceps brachii injury. (Am J Vet Res2005;66:391–400)
Evaluation of developmental changes in the coexpression of myosin heavy chains and metabolic properties of equine skeletal muscle fibers
Authors: Yamano Seiko , Eto Daisuke , Kasashima Yoshinori , Hiraga Atushi , Sugiura Takao , Miyata Hirofumi 
Published: December 2005

Abstract

Objective—To determine the growth-related changes
in metabolic and anatomic properties in equine muscle
fiber type, including hybrid fibers identified with
immunohistochemical analysis.

Animals—24 2-, 6-, 12-, and 24-month-old female
Thoroughbreds.

Procedure—Samples were obtained from the gluteus
medius muscle of all horses. Expression of
myosin heavy chain (MHC) isoforms MHC-I, -IIa, -IIb,
and -IIx in each muscle fiber was detected by use of
4 primary monoclonal antibodies: BA-D5, SC-71, BFF3,
and BF-35, respectively. Five muscle fiber types
(types I, I/IIA, IIA, IIA/IIX, and IIX) were immunohistochemically
identified. The area and activity of succinic
dehydrogenase (SDH) in each fiber type were determined
by use of quantitative histochemical staining
and image analysis.

Results—Although the proportion of type I and IIX
fibers did not change with age, the proportion of type
IIA and IIA/IIX fibers significantly increased and
decreased, respectively, from 2 months to 24 months
of age. The increase in proportion of type IIA fibers
with growth may have been attributable to muscle
fiber-type transition from type IIA/IIX fibers but not
from type IIX fibers. Values for SDH activity and fiber
area in hybrid fiber types were intermediate to those
for their respective pure phenotypes.

Conclusions and Clinical Relevance—Hybrid fibers
have an important role for determining the proportion
of muscle fiber type in horses < 24 months old, and
the metabolic and anatomic properties of the hybrid
fibers are well coordinated, as in mature horses.
(Am J Vet Res 2005;66:401–405)
Effects of ranitidine, famotidine, pantoprazole, and omeprazole on intragastric pH in dogs
Authors: Bersenas Alexa M. E. , Mathews Karol A. , Allen Dana G. , Conlon Peter D. 
Published: December 2005

Abstract

Objective—To identify the normal gastric acid secretion
profile in dogs and determine the degree of gastric
acid suppression associated with 4 gastric acid
suppressants.

Animals—12 healthy Beagles.

Procedure—Intragastric pH was measured continuously
for 24-hour periods with a digital recording system
placed via a gastrostomy tube. Baseline measurements
were obtained when food was withheld
and when dogs were fed a standard diet. Dogs were
then treated with ranitidine (2 mg/kg, IV, q 12 h),
famotidine (0.5 mg/kg, IV, q 12 h), pantoprazole
(1 mg/kg, IV, q 24 h), omeprazole (1 mg/kg, PO, q 24
h), or saline solution for 7 days; intragastric pH was
recorded on days 0, 2, and 6. Subsequently, the
effects of administering famotidine (0.5 mg/kg, IV, q 8
h; 6 dogs) and omeprazole as a suspension (1 mg/kg,
PO, q 12 h; 6 dogs) were evaluated. Median 24-hour
intragastric pH, percentage of time pH was ≥ 3, and
percentage of time pH was ≥ 4 were determined.

Results—Median pH, percentage of time pH was ≥ 3,
and percentage of time pH was ≥ 4 were all significantly
higher when food was withheld than when
dogs were fed. Famotidine, pantoprazole, and
omeprazole significantly suppressed gastric acid
secretion, compared with saline solution, as determined
on the basis of median 24-hour pH and percentages
of time pH was ≥ 3 or ≥ 4. However, ranitidine
did not. Omeprazole suspension suppressed
gastric acid secretion.

Conclusions and Clinical Relevance—Results suggest
that in healthy dogs, famotidine, pantoprazole,
and omeprazole significantly suppress gastric acid
secretion. Twice daily administration of a suspension
of omeprazole, was the only regimen tested that
approached the potential therapeutic efficacy for acidrelated
disease when assessed by criteria used for
human patients. (Am J Vet Res 2005;66:425–431)
Effects of vehicle and region of application on absorption of hydrocortisone through canine skin
Authors: Mills Paul C. , Magnusson Beatrice M. , Cross Sheree E. 
Published: December 2005

AbstractObjective—To determine the effects of various vehicles on the penetration and retention of hydrocortisone applied to canine skin.Sample Population—20 canine skin samples obtained from the thorax, neck, and groin regions of 5 Greyhounds.Procedure—Skin was harvested from dogs after euthanasia and stored at –20°C until required. The skin was then defrosted and placed into diffusion cells, which were maintained at approximately 32°C by a water bath. Saturated solutions of hydrocortisone that contained trace amounts of radiolabelled [14C]-hydrocortisone in each vehicle (ie, PBS solution [PBSS] alone, 50% ethanol [EtOH] in PBSS [wt/wt], and 50% propylene glycol in PBSS [wt/wt]) were applied to the outer (stratum corneum) surface of each skin sample, and aliquots of receptor fluid were collected for 24 hours and analyzed for hydrocortisone.Results—The maximum flux of hydrocortisone was significantly higher for all sites when dissolved in a vehicle containing 50% EtOH, compared with PBSS alone or 50% propylene glycol, with differences more prominent in skin from the neck region. In contrast, higher residues of hydrocortisone were found remaining within the skin when PBSS alone was used as a vehicle, particularly in skin from the thorax and neck.Conclusions and Clinical Relevance—Penetration of topically applied hydrocortisone is enhanced when EtOH is used in vehicle formulation. Significant regional differences (ie, among the thorax, neck, and groin areas) are also found in the transdermal penetration and skin retention of hydrocortisone. Variability in clinical response to hydrocortisone can be expected in relation to formulation design and site of application. (Am J Vet Res2005;66:43–47)
Expression of erythropoietin in cats treated with a recombinant adeno-associated viral vector
Authors: Walker Mark C. , Mandell Tamara C. , Crawford P. Cynda , Simon Greg G. , Cahill Kevin S. , Fernandes Peter J. , MacLeod James N. , Byrne Barry J. , Levy Julie K. 
Published: December 2005

AbstractObjective—To characterize the biological effects of IM administration of a recombinant adeno-associated virus serotype 2 (rAAV2) vector containing feline erythropoietin (fEPO) cDNA and determine whether readministration of the vector or removal of muscle tissue at the injection sites alters those effects.Animals—10 healthy 7-week-old specific pathogenfree cats.Procedure—Cats received 1 × 107infective units (iU; n = 3), 1 × 108iU (3), or 1 × 109iU (2) of rAAV2-fEPO vector IM (day 0). Two control cats received an rAAV2 vector containing the LacZ gene (1 × 109iU, IM). In all cats, hematologic variables and serum fEPO concentration were measured at intervals; anti-rAAV2 antibody titer was measured on day 227. In cats that did not respond to treatment, the rAAV2- fEPO vector was readministered. Injection sites were subsequently surgically removed.Results—Compared with control cats, cats treated with 1 × 109iU of rAAV2-fEPO vector had increased Hct and serum fEPO concentrations. One of these cats developed pure RBC aplasia; its Hct normalized following injection site excision. Cats receiving lower doses of vector had no response; on retreatment, 1 of those cats developed sustained erythrocytosis that persisted despite injection site removal and the others did not respond or responded transiently. Antibodies against rAAV2 were detected in all vector-treated cats.Conclusions and Clinical Relevance—Gene therapy may be an effective treatment for cats with hypoproliferative anemia. However, rAAV2-fEPO vector administration may result in pure RBC aplasia or pathologic erythrocytosis, and injection site removal does not consistently abolish the biological response. (Am J Vet Res2005;66:450–456)
Investigation of antigen-specific T-cell responses and subcutaneous granuloma development during experimental sensitization of calves with Mycobacterium avium subsp paratuberculosis
Authors: Simutis Frank J. , Cheville Norman F. , Jones Douglas E. 
Published: December 2005

AbstractObjective—To characterize the early cellular immune response toMycobacterium aviumsubspparatuberculosis( MAP) infection and evaluate the development of granulomatous inflammation at the SC injection site in experimentally inoculated calves.Animals—Forty-eight 4-week-old calves.Procedure—Calves received an SC injection of MAP strain 19698 (n = 25), sterile saline (0.9% NaCl) solution (20), or a commercial paratuberculosis vaccine (3); the inoculation site tissue and associated draining lymph node were excised at postinoculation day (PID) 0 (n = 36), 7 (14), 14 (6), 21 (8), and 60 (32). Sections of inoculation site tissues were evaluated immunohistochemically for T-cell subsets; lymph node mononuclear cells (LNMCs) were assessed for T-cell surface markers and for intracellular interferon-γ via flow cytometry.Results—At MAP inoculation sites, calves developed mild, focal granulomatous inflammation by PID 7; by PID 60, areas of inflammation contained macrophages with numerous lymphocytes. Compared with control calves, there was increased antigen-specific LNMC proliferation in MAP- and vaccine- inoculated calves at PID 60, although proliferation among lymphocyte subsets was not significantly different between MAP-inoculated and control calves; in vaccine-inoculated calves, CD4+ T-cells predominated. In MAP-inoculated and control calves, antigenspecific interferon-γ production by LNMCs did not differ significantly; vaccine-inoculated calves had marked interferon-γ expression by CD4+ T-cells.Conclusions and Clinical Relevance—In calves, SC administration of MAP resulted in granulomatous inflammation at inoculation sites and an antigen-specific T-cell proliferative response. Results suggest that this experimental system can be used to reproducibly generate antigen-specific T-cells during MAP infection for functional analysis. (Am J Vet Res2005;66:474–482)
Effects of CD28 blockade on subsets of naïve T cells in cats
Authors: Aronson Lillian R. , Drobatz Kenneth J. , Hunter Christopher A. , Mason Nicola 
Published: December 2005

AbstractObjective—To determine whether human CTLA4-Ig ([hu]CTLA4-Ig) inhibits costimulation-dependent lymphocyte proliferation in vitro, compare the effects of (hu)CTLA4-Ig with cyclosporine and steroids on CD4+ and CD8+ T-cell lymphocyte proliferation, and determine whether memory T-cell function remains intact in the presence of (hu)CTLA4-Ig.Animals—29 cats.Procedure—Peripheral blood mononuclear cells (PBMCs) were stimulated with concanavalin A (costimulation- dependent mitogen) or phorbol 12-myristate 13-acetate and ionomycin (costimulation independent mitogens) alone or in the presence of (hu)CTLA4-Ig, cyclosporine, or dexamethasone; effects of these treatments on lymphocyte proliferation were assessed by incorporation of thymidine labeled with tritium or flow cytometry. Antigen-specific proliferation was determined by stimulating PBMCs from 2 healthy cats seropositive forToxoplasma gondiiwith solubleToxoplasmaantigen alone or in the presence of (hu)CTLA4-Ig or cyclosporine.Results—(hu)CTLA4-Ig inhibited costimulationdependent lymphocyte proliferation in vitro but had no effect on costimulation-independent lymphocyte proliferation. Compared with mitogen alone, (hu)CTLA4-Ig caused a significant decrease in responder frequency and proliferative capacity of CD4+ T cells; however, the effect on CD8+ T cells was not significant. Cyclosporine alone or with dexamethasone had a significantly greater suppressive effect on responder frequency and proliferative capacity of CD4+ and CD8+ T cells, compared with (hu)CTLA4-Ig. Compared with cyclosporine, (hu)CTLA4-Ig appeared to have a sparing effect on antigen-specific proliferation of memory CD4+ and CD8+ T cells.Conclusions and Clinical Relevance—(hu)CTLA4-Ig selectively inhibited costimulation-dependent proliferation of lymphocytes in vitro and had a sparing effect on antigen-specific proliferation of memory cells. The specificity of its mechanism of action suggests that (hu)CTLA4-Ig may prevent allograft rejection but leave memory responses to previously encountered antigens intact. (Am J Vet Res2005;66:483–492)
Ultrasonographic measurement of abomasal volume, location, and emptying rate in calves
Authors: Wittek Thomas , Constable Peter D. , Marshall Tessa S. , Crochik Sonia S. 
Published: December 2005

AbstractObjective—To develop and validate an ultrasonographic method for measuring abomasal volume, location, and emptying rate in suckling calves.Animals—9 male Holstein calves < 40 days of age.Procedure—Before and after calves were fed different volumes of milk replacer or 2 L of oral electrolyte solutions, ultrasonographic measurements of abomasal dimensions (width, length, and height) were obtained by applying a 3.5-MHz sector probe to the ventral aspect of the abdomen in the transverse and sagittal planes. Abomasal volume was calculated from the ultrasonographic measurements by modeling the abomasum as an ellipsoid and by use of a power exponential equation to calculate the half-time of abomasal emptying (t1/2).Results—Preprandial abomasal volume was 20 to 137 mL. All 3 abomasal dimensions increased during feeding and after suckling, and the abomasum was symmetrically located about the midline of the ventral aspect of the abdomen. Strong linear relationships were identified between ultrasonographic and suckled volumes, between ultrasonographic and scintigraphic heights, and between ultrasonographic and scintigraphic lengths. Ultrasonographic t1/2was linearly related to scintigraphic t1/2; the latter is regarded as the gold standard measure of gastric emptying rate.Conclusions and Clinical Relevance—Ultrasonographic evaluation of the abomasum appears to provide a practical, rapid, noninvasive, and accurate method for determination of abomasal volume, location, and emptying rate in suckling calves. (Am J Vet Res2005;66:537–544)