bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of an interdental full pin on stability of an acrylic external fixator for rostral mandibular fractures in dogs
Authors: Cook Wesley T. , Smith Mark M. , Markel Mark D. , Grant J. Wallace 
Published: December 2005

AbstractObjective—To determine total stiffness and gap stiffness of an external fixation system in a canine mandibular fracture gap model incorporating a full interdental pin as the only point of rostral fixation in a bilateral type-I external fixator.Sample Population—10 canine mandibles.Procedure—Bilateral mandibular ostectomies were performed between premolars 3 and 4. A type-I external fixator incorporating a full interdental pin was placed to stabilize a 0.5-cm fracture gap. Four pin configurations (intact mandibular bodies with fixator; ostectomized mandibular bodies and complete fixator; ostectomized mandibular bodies with caudal pins of rostral fragment cut; ostectomized mandibular bodies with all pins of rostral fragment cut) were tested in dorsoventral bending 5 times on each mandible. The full interdental pin remained intact in all configurations. Total stiffness and gap stiffness were determined for each configuration on a materials testing machine.Results—Total stiffness of intact mandibles was significantly greater than that of ostectomized mandibles, regardless of external fixator configuration. However, total stiffness and gap stiffness were not significantly different among different external fixator configurations applied to ostectomized mandibles.Conclusion and Clinical Relevance—External fixator configurations with only the full interdental pin engaging the rostral fragment were as stiff as configurations that had 2 or 4 additional pins in the rostral fragment for the applied loads. External fixators for rostral mandibular fractures may be rigidly secured with rostral fragment implants applied extracortically, avoiding iatrogenic trauma to teeth and tooth roots. (Am J Vet Res2001;62:576–580)
In vitro characterization of FIV-pPPR, a pathogenic molecular clone of feline immunodeficiency virus, and two drug-resistant pol gene mutants
Authors: Stevenson M. A. McCrackin , McBroom Douglas G. 
Published: December 2005

Abstract

Objective—To compare in vitro replication kinetics
and nucleoside analog susceptibilities of a natural
feline immunodeficiency virus (FIV) isolate (FIV-Maxam),
a molecular clone of FIV (FIV-pPPR), and
two (-)-β-L-2',3'-dideoxy-3'-thiacytidine- (3TC-) resistant
mutants of FIV-pPPR.

Sample Population—Peripheral blood mononuclear
cells (PBMC) from 4 specific-pathogenfree cats.

Procedure—Two point mutations corresponding to
mutations of human immunodeficiency virus type 1
(HIV-1) were engineered into the highly conserved
YMDD motif of the reverse transcriptase- (RT-) encoding
region of the FIV-pPPR pol gene. Replication kinetics
and nucleoside analog susceptibilities of FIV-Maxam,
FIV-pPPR, and the 2 mutant viruses were
measured in vitro, using feline PBMC.

Results—Replication kinetics and nucleoside analog
susceptibilities were similar between FIV-Maxam and
FIV-pPPR. However, FIV-Maxam was significantly
more susceptible to 3TC. A methionine-to-valine
mutation at codon 183 (M183V) of the RT-encoding
region of the pol gene of FIV-pPPR conferred highlevel
phenotypic resistance to 3TC and cross-resistance
to the related compound (-)-β-L-2',3'-dideoxy-5-
fluoro-3'-thiacytidine.

Conclusion and Clinical Relevance—Similarities
between FIV-Maxam and FIV-pPPR suggest that
results of studies performed using FIV-pPPR will have
relevance to natural FIV infection in cats. In vitro evaluation
of nucleoside analog susceptibilities of FIV-Maxam
may help determine concentrations of nucleoside
analogs required for effective treatment of FIV-infected
cats.

Impact for Human Medicine—3TC resistance of
FIV-pPPR M183V was similar in magnitude to that of
HIV-1 M184V, a mutant described in infected humans
treated with 3TC. Thus, FIV-pPPR M183V may be a
useful model for studying the in vivo effects of 3TC
resistance on lentivirus pathogenesis. (Am J Vet Res
2001;62:588–594)
Amidolytic heparin activity and values for several hemostatic variables after repeated subcutaneous administration of high doses of a low molecular weight heparin in healthy dogs
Authors: Mischke Reinhard , Grebe Susanne , Jacobs Christina , Kietzmann Manfred 
Published: December 2005

AbstractObjective—To determine effects of SC administration of repeated doses of a low molecular weight heparin (LMWH) in dogs.Animals—5 healthy dogs.Procedure—Each dog received 6 injections (each injection, 150 U of anti-factor-Xa [anti-FXa]/kg of body weight, SC) at 8-hour intervals. Blood samples were collected before and 2 hours after the first, second, third, and sixth injections to measure heparin activity, thrombin time, activated partial thromboplastin time (APTT), antithrombin activity, Hct, and platelet count.Results—Heparin activity varied between 0.36 ± 0.10 and 0.77 ± 0.08 U of anti-FXa/ml (before and 2 hours after the third injection) and between 0.46 ± 0.11 and 0.82 ± 0.15 U of anti-FXa/ml (before and 2 hours after the sixth injection). Thrombin time and APTT were influenced only slightly. Platelet count, Hct, and antithrombin activity started to decrease significantly 2 hours after the second LMWH injection. Because of the increased consumption of antithrombin, antithrombin activity continuously decreased from 102.1 ± 6.3% before the study to 91.0 ± 3.0% at the end of the study.Conclusion and Clinical Relevance—Heparin plasma activity was only slightly higher than that recommended for LMWH treatment of humans, and none of the dogs had signs of increased bleeding. Thus, administration of heparin in accordance with this dosing regimen can be recommended for use in clinical studies. The screening tests investigated were not suitable for use in monitoring LMWH treatment of dogs. Assays that use chromogenic substrates are necessary to reliably monitor LMWH plasma concentrations in dogs. (Am J Vet Res2001;62:595–598)
Relationship between mean body surface temperature measured by use of infrared thermography and ambient temperature in clinically normal pigs and pigs inoculated with Actinobacillus pleuropneumoniae
Authors: Loughmiller Joseph A. , Spire Mark F. , Dritz Steve S. , Fenwick Bradley W. , Hosni Mohammad H. , Hogge Steven B. 
Published: December 2005

AbstractObjective—To determine the relationship between ambient temperature and mean body surface temperature (MBST) measured by use of infrared thermography (IRT) and to evaluate the ability of IRT to detect febrile responses in pigs following inoculation withActinobacillus pleuropneumoniae.Animals—28 crossbred barrows.Procedures—Pigs (n = 4) were subjected to ambient temperatures ranging from 10 to 32 C in an environmental chamber. Infrared thermographs were obtained, and regression analysis was used to determine the relationship between ambient temperature and MBST. The remaining pigs were assigned to groups in an unbalanced randomized complete block design (6A pleuropneumoniae-inoculated febrile pigs [increase in rectal temperature ≥ 1.67 C], 6A pleuropneumoniae-inoculated nonfebrile pigs [increase in rectal temperature < 1.67 C], and 12 noninoculated pigs). Infrared thermographs and rectal temperatures were obtained for the period from 2 hours before to 18 hours after inoculation, and results were analyzed by use of repeated-measures ANOVA.Results—A significant linear relationship was observed between ambient temperature and MBST (slope, 0.40 C). For inoculated febrile pigs, a treatment X method interaction was evident for rectal temperature and MBST, whereas inoculated nonfebrile pigs only had increased rectal temperatures, compared with noninoculated pigs. A method X time interaction resulted from the longer interval after inoculation until detection of an increase in MBST by use of IRT.Conclusions and Clinical Relevance—Infrared thermography can be adjusted to account for ambient temperature and used to detect changes in MBST and radiant heat production attributable to a febrile response in pigs. (Am J Vet Res2001;62:676–681)
Intranasal vaccination of rabbits with Pasteurella multocida A:3 outer membranes that express iron-regulated proteins
Authors: Confer Anthony W. , Suckow Mark A. , Montelongo Marie , Dabo S. Mady , Miloscio Lawrence J. , Gillespie Arden J. , Meredith Glacia L. 
Published: December 2005

AbstractObjective—To determine efficacy of intranasal vaccination of rabbits withPasteurella multocidaA:3 outer membrane proteins (OMP) expressing iron-regulated OMP (IROMP) in conferring protection against experimental challenge exposure.Animals—52 male New Zealand White rabbits.Procedure— Rabbits were vaccinated intranasally on days 0, 7, and 14; some vaccines included cholera toxin (CT) as an adjuvant. Concentrations of intranasal IgA and serum IgG antibodies againstP multocidaOMP were determined. In experiment A, rabbits were vaccinated with either phospate-buffered saline solution (PBSS), PBSS-CT, OMP-CT, or IROMP-CT, challenge-exposed intranasally on day 16, and euthanatized and necropsied on day 28. Rabbits were also vaccinated with OMP or IROMP without CT and were not challenge-exposed. In experiment B, rabbits were vaccinated with PBSS, PBSS-CT, IROMP, or IROMP-CT. On day 17, rabbits were challenge-exposed intranasally .Nasal bacteria and antibodies were determined on day 24.Results—In experiment A, OMP-CT vaccination stimulated mucosal and systemic antibody responses to the bacterium and enhanced resistance against challenge exposure. Intranasal bacterial counts were not significantly reduced. Vaccination with IROMP-CT stimulated mucosal and systemic antibodies, enhanced resistance to challenge exposure, and significantly reduced nasal bacterial counts. In experiment B, natural infection was detected in several rabbits at challenge exposure; however, IROMP-CT-vaccinated rabbits had significantly higher serum and nasal antibody responses, compared with other rabbitsIROMP-CT-vaccinated rabbits had significantly lower nasal bacterial counts compared to control rabbits.Conclusions and Clinical Relevance—Intranasal vaccination of rabbits withP multocidaouter membranes containing IROMP and CT stimulated immunity against experimental pneumonic pasteurellosis. (Am J Vet Res2001;62:697–703)
Evaluation of polymyxin B in an ex vivo model of endotoxemia in horses
Authors: Parviainen Anna K. , Barton Michelle H. , Norton Natalie N. 
Published: December 2005

AbstractObjective— To evaluate effects of polymyxin B sulfate (PMB) on response of horses to endotoxin, using an ex vivo model.Animals—8 healthy horses.Procedure—In a crossover design, 3 doses of PMB (100, 1,000, and 10,000 U/kg of body weight) and physiologic saline solution (control) were evaluated. Prior to and for 24 hours after administration of PMB, blood samples were collected into heparinized tubes for use in 2 assays. For the endotoxin-induced tumor necrosis factor (TNF) assay, blood samples were incubated (37 C for 4 h) with 1 ng ofEscherichia coliorSalmonellaTyphimurium endotoxin/ml of blood. Plasma was harvested and assayed. For the residual endotoxin activity assay, plasma was collected into sterile endotoxin-free borosilicate tubes, diluted 1:10 with pyrogen-free water, and incubated for 10 minutes at 70 C.Escherichia coliendotoxin (0.1 or 1 ng/ml of plasma) was added to the thawed samples prior to performing the limulus ameobocyte lysate assay. Serum creatinine concentrations were monitored for 1 week.Results—Compared with baseline values, PMB caused a significant dose- and time- dependent decrease in endotoxin-induced TNF activity. Compared with baseline values, residual endotoxin activity was significantly reduced after administration of 10,000 U of PMB/kg. Compared with baseline values, 1,000 and 5,000 U of PMB/kg should inhibit 75% of endotoxin-induced TNF activity for 3 and 12 hours, respectively. Serum creatinine concentrations remained within the reference range.Conclusion and Clinical Relevance—Results of the study suggest that PMB is a safe, effective inhibitor of endotoxin-induced inflammation in healthy horses. (Am J Vet Res2001; 62:72–76)
Comparison of bending modulus and yield strength between outer stratum medium and stratum medium zona alba in equine hooves
Authors: Wagner Ilka P. , Hood David M. , Hogan Harry A. 
Published: December 2005

AbstractObjective—To determine whether the bending modulus and yield strength of the outer stratum medium (SM) differed from those of the SM zona alba (SMZA) and to what degree they differed. In addition, a comparison was made among our values and values reported elsewhere.Sample Population—10 normal equine feet.Procedure—A 3-point bending technique was used to determine the bending modulus and yield strength of the outer SM and SMZA. Efforts were made to minimize biological and technical factors that could influence the bending modulus.Results—Bending modulus of the outer SM was (mean ± SD) 187.6 ± 41.3 MPa, whereas mean value for the SMZA was 98.2 ± 36.8 MPa. Mean yield strength was 19.4 ± 2.6 MPa for the outer SM and 5.6 ± 1.7 MPa for the SMZA. Values for bending modulus and yield strength differed significantly between the outer SM and SMZA. Significant differences were not detected when the outer SM was loaded in bending from the outer or inner surface.Conclusions and Clinical Relevance—Potentially, the SMZA could serve as a mechanical buffer zone between the rigid hoof wall and bone and laminar tissues. This buffer zone potentially assists the feet of horses in transmitting a load through the tissues and prevents the most susceptible tissues from becoming damaged. More consistency among tissue selection, preparation, and testing protocols must be attained before an accurate 3-dimensional finite-element model of an equine foot can be constructed. (Am J Vet Res2001;62:745–751)
Evaluation of dual energy x-ray absorptiometry for in situ measurement of bone mineral density of equine metacarpi
Authors: McClure Scott R. , Glickman Lawrence T. , Glickman Nita W. , Weaver Connie M. 
Published: December 2005

AbstractObjective—To determine the accuracy and precision of dual energy x-ray absorptiometry (DEXA) for measuring bone mineral density in horses in situ.Sample Population—12 randomly selected forelimbs from 12 horses.Procedure—Metacarpi were scanned in 2 planes and DEXA measurements obtained for 6 regions of interest (ROI). Each ROI was isolated and bone density measured by Archimedes' principle. Linear regression analysis was used to determine the correlation between the 2 measurements at each ROI. An additional metacarpus was measured 10 times to determine the coefficient of variation for both techniques.Results—Dual energy x-ray absorptiometry and bone density were significantly associated at multiple ROI. The addition of age, weight, and soft tissue or bone thickness improved these associations. Repeated measurements had a low coefficient of variation.Conclusions and Clinical Relevance—Dual energy x-ray absorptiometry can be used to accurately and precisely measure the bone density in the equine metacarpus. Dual energy x-ray absorptiometry appears suitable for serial in vivo measurement of bone density of the equine metacarpus. Dual energy x-ray absorptiometry may be used for studies to evaluate the effects of diet or drugs on bone density or density changes from bone remodeling that develop prior to stress fractures. (Am J Vet Res2001; 62:752–756)
Basic three-dimensional kinematics of the vertebral column of horses trotting on a treadmill
Authors: Faber Marjan , Johnston Christopher , Schamhardt Henk , Weeren René van , Roepstorff Lars , Barneveld Ab 
Published: December 2005

Abstract

Objective—To determine movements of the vertebral
column of horses during normal locomotion.

Animals—5 young Dutch Warmblood horses that did
not have signs of back problems or lameness.

Procedure—Kinematics of 8 vertebrae (T6, T10, T13,
T17, L1, L3, L5, and S3) and both tuber coxae were
determined, using bone-fixated markers. Measurements
were recorded when the horses were trotting
on a treadmill at a constant speed of 4.0 m/s.

Results—Flexion-extension and axial rotation were
characterized by a double sinusoidal pattern of motion
during 1 stride cycle, whereas lateral bending was
characterized by 1 peak and 1 trough. Ranges of
motion for all vertebrae were: flexion-extension, 2.8o
to 4.9o; lateral bending, 1.9° to 3.6°; axial rotation, 4.6°
to 5.8°, except for T10 and T13, where the amount of
axial rotation decreased to 3.1° and 3.3°, respectively.

Conclusion and Clinical Relevance—During locomotion,
3 types of rotations are evident in the thoracolumbar
vertebrae. Regional differences are
observed in the shape and timing of the rotations.
These differences are related to actions of the limbs.
The method described here for direct measurement
of vertebral column motion provides insights into the
complex movements of the thoracolumbar portion of
the vertebral column in trotting horses. Information
on normal kinematics is a prerequisite for a better
understanding of abnormal function of the vertebral
column in horses. (Am J Vet Res 2001;62:757–764)
Pharmacokinetics of imipramine in narcoleptic horses
Authors: Peck Kenneth E. , Hines Melissa T. , Mealey Katrina L. , Mealey Robert H. 
Published: December 2005

AbstractObjective—To validate use of high-performance liquid chromatography (HPLC) in determining imipramine concentrations in equine serum and to determine pharmacokinetics of imipramine in narcoleptic horses.Animals—5 horses with adult-onset narcolepsy.Procedure—Blood samples were collected before (time 0) and 3, 5, 10, 15, 20, 30, and 45 minutes and 1, 2, 3, 4, 6, 8, 12, and 24 hours after IV administration of imipramine hydrochloride (2 or 4 mg/kg of body weight). Serum was analyzed, using HPLC, to determine imipramine concentration. The serum concentration-versus-time curve for each horse was analyzed separately to estimate pharmacokinetic values.Results—Adverse effects (muscle fasciculations, tachycardia, hyperresponsiveness to sound, and hemolysis) were detected in most horses when serum imipramine concentrations were high, and these effects were most severe in horses receiving 4 mg of imipramine/kg. Residual adverse effects were not apparent. Value (mean ± SD) for area under the curve was 3.9 ± 0.7 h × μg/ml, whereas volume of distribution was 584 ± 161.7 ml/kg, total body clearance was 522 ± 102 ml/kg/h, and mean residence time was 1.8 ± 0.6 hours. One horse had signs of narcolepsy 6 and 12 hours after imipramine administration; corrresponding serum imipramine concentrations were less than the therapeutic range.Conclusions and Clinical Relevance—Potentially serious adverse effects may be seen in horses administered doses of imipramine that exceed a dosage of 2 mg/kg. Total body clearance of imipramine in horses is slower than that in humans; thus, the interval between subsequent doses should be longer in horses. (Am J Vet Res2001;62:783–786)
Site-specific adaptive remodeling of Greyhound metacarpal cortical bone subjected to asymmetrical cyclic loading
Authors: Johnson Kenneth A. , Skinner Gerry A. , Muir Peter 
Published: December 2005

AbstractObjective—To quantify geometric, inertial, and histomorphometric properties at the mid-diaphyseal level of left and right metacarpal bones (MCB) of racing Greyhounds.Sample Population—MCB from 7 racing Greyhounds euthanatized for reasons unrelated to MCB abnormalities.Procedures—Mid-diaphyseal transverse sections of left and right MCB were stained with H&E or microradiographed. Images of stained sections were digitized, and cross-sectional area, cortical area, and maximum and minimum area moments of inertia of each bone were determined. Histomorphometric data (osteonal density, osteonal birefringence, and endosteal new lamellar bone thickness) were collected in 4 quadrants (dorsal, palmar, lateral, medial). Values were compared between limbs and among bones and quadrants.Results—Cross-sectional area, cortical area, and maximum and minimum moments of inertia of left MCB-IV and -V were significantly greater, compared with contralateral bones. Overall osteonal densities in the dorsal quadrants of left MCB were greater, compared with lateral and medial quadrants. Also, percentage of birefringent osteons was significantly greater in the dorsal quadrant of left MCB-III, -IV, and -V, compared with the palmar quadrant. Thickness of new endosteal lamellar bone was not significantly influenced by limb, bone, or quadrant.Conclusions and Clinical Relevance—Increased cortical thickness and geometric properties of left MCB-IV and -V of Greyhounds, together with altered turnover and orientation of osteons in the dorsal quadrants of left MCB, are site-specific adaptive responses associated with asymmetric cyclic loading as a result of racing on circular tracks. Site-specific adaptive remodeling may be important in the etiopathogenesis of fatigue fractures in racing Greyhounds. (Am J Vet Res2001;62:787–793)
Development of an ex vivo model to study adherence of Mannheimia haemolytica serovar 1 to mucosal tissues of the respiratory tract of cattle
Authors: Clarke Jean M. , Morton Rebecca J. , Clarke Cyril R. , Fulton Robert W. , Saliki Jeremiah T. 
Published: December 2005

AbstractObjective—To develop and validate an ex vivo model for study of adherence ofMannheimia haemolytica(formerlyPasteurella haemolytica) to respiratory tract mucosa of cattle and to use this model to confirm adherence ofM haemolyticaserovar 1 (Mh1) to several relevant respiratory mucosal surfaces.Sample Population—Excised nasal, nasopharyngeal, turbinate, and tonsillar mucosal tissue from the bovine upper respiratory tract.Procedure—Mh1 was radiolabeled by use of tritiated leucine. Various concentrations of labeled bacteria were incubated with bovine upper respiratory tract tissues for various times. Tissue was washed to remove nonadherent bacteria, and percentage of bacteria adhered (percentage of adherence) was estimated using radioactivity. Using an optimal inoculum concentration and incubation time, percentage of Mh1 adherence was compared on nasal, nasopharyngeal, turbinate, and tonsillar mucosal tissue, and adherence to nasopharyngeal tissue was confirmed by scanning and transmission electron microscopy.Results—The optimal Mh1 inoculum concentration was 1 × 107colony forming units/ml and incubation time was 3 hours. Percentage of adherence of Mh1 to nasopharyngeal tissue was greater than adherence to other tissue types.Conclusions and Clinical Relevance—The ex vivo model maintained the functional and structural integrity of bovine upper respiratory tract mucosa, as confirmed by light and electron microscopy. Electron microscopy revealed participation of epithelial cell cilia and surface mucus in adherence of Mh1 to nasopharyngeal tissue. Adherence of Mh1 was confirmed in repeated assays, indicating that this organism adheres to upper respiratory tract mucosa of cattle. (Am J Vet Res2001;62:805–811)