bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in kinematic variables observed during pressure-induced forelimb lameness in adult horses trotting on a treadmill
Authors: Keegan Kevin G. , Wilson David A. , Smith Bryan K. , Wilson Daniel J.
Published: December 2005

Objective—To determine whether kinematic changes induced by heel pressure in horses differ from those induced by toe pressure.

Animals—10 adult Quarter Horses.

Procedure—A shoe that applied pressure on the cuneus ungulae (frog) or on the toe was used. Kinematic analyses were performed before and after 2 levels of frog pressure and after 1 level of toe pressure. Values for stride displacement and time and joint angles were determined from horses trotting on a treadmill.

Results—The first level of frog pressure caused decreases in metacarpophalangeal (fetlock) joint extension during stance and increases in head vertical movement and asymmetry. The second level of frog pressure caused these changes but also caused decreases in stride duration and carpal joint extension during stance as well as increases in relative stance duration. Toe pressure caused changes in these same variables but also caused maximum extension of the fetlock joint to occur before midstance, maximum hoof height to be closer to midswing, and forelimb protraction to increase.

Conclusion and Clinical Relevance—Decreased fetlock joint extension during stance and increased head vertical movement and asymmetry are sensitive indicators of forelimb lameness. Decreased stride duration, increased relative stance duration, and decreased carpal joint extension during stance are general but insensitive indicators of forelimb lameness. Increased forelimb protraction, hoof flight pattern with maximum hoof height near midswing, and maximum fetlock joint extension in cranial stance may be specific indicators of lameness in the toe region. Observation of forelimb movement may enable clinicians to differentiate lameness of the heel from lameness of the toe. (Am J Vet Res2000;61:612-619)
Effects of warm-up intensity on kinetics of oxygen consumption and carbon dioxide production during high-intensity exercise in horses
Authors: Geor Raymond J. , McCutcheon L. Jill , Hinchcliff Kenneth W.
Published: December 2005

Objective—To compare effects of low and high intensity warm-up exercise on oxygen consumption (O2) and carbon dioxide production (CO2) in horses. Animals—6 moderately conditioned adult Standardbreds.

Procedures—Horses ran for 2 minutes at 115% of maximum oxygen consumption (O2max), 5 minutes after each of the following periods: no warm-up (NoWU); 10 minutes at 50% ofO2max (LoWU); or 7 minutes at 50%O2max followed by 45-second intervals at 80, 90, and 100%O2max (HiWU). Oxygen consumption andCO2were measured during exercise, and kinetics ofO2andCO2were calculated. Accumulated O2deficit was also calculated.

Results—For both warm-up trials, the time constant for the rapid exponential increase inO2was 30% lower than for NoWU. Similarly, the rate of increase inCO2was 23% faster in LoWU and HiWU than in NoWU. Peak values forO2achieved during the highspeed test were not significantly different among trials (LoWU, 150.2 ± 3.2 ml/kg/min; HiWU, 151.2 ± 4.2 ml/kg/min; NoWU, 145.1 ± 4.1 ml/kg/min). However, accumulated O2deficit (ml of O2equivalents/kg) was significantly lower during LoWU (65.3 ± 5.1) and HiWU (63.4 ± 3.9) than during NoWU (82.1 ± 7.3).

Conclusions and Clinical Relevance—Both the lowand high-intensity warm-up, completed 5 minutes before the start of high-intensity exercise, accelerated the kinetics ofO2andCO2and decreased accumulated O2 deficit during 2 minutes of intense exertion in horses that were moderately conditioned. (Am J Vet Res2000;61:638–645)
Pathophysiologic correlates of acute porcine pleuropneumonia
Authors: Baarsch Mary Jo , Foss Dennis L. , Murtaugh Michael P.
Published: December 2005

Objective—To develop and evaluate an in vivo model to study early events in the pathogenesis of acute porcine pleuropneumonia.

Animals—Thirty-six 6- to 8-week-old pigs.

Procedure—Pigs were inoculated intranasally or endotracheally withActinobacillus pleuropneumoniae; inoculation routes were compared by evaluation of clinical signs, gross and microscopic lung lesions, hematologic changes, serum zinc, iron, and haptoglobin concentrations, and inflammatory cytokines.

Results—The 2 inoculation routes resulted in similar findings, although intranasal inoculation caused unilateral gross lung lesions, whereas endotracheal inoculation caused bilateral gross lesions. Clinical signs of disease were observed < 2 hours after endotracheal inoculation and 6 to 8 hours after intranasal inoculation. Total WBC counts did not differ significantly after inoculation by either inoculation route, although band neutrophils increased significantly. The earliest findings associated withA pleuropneumoniaeinoculation, irrespective of route, were decreased serum zinc and iron concentrations. Serum haptoglobin concentrations were significantly increased after inoculation. Inoculation induced rapid influx of macrophages into the lung and local induction of proinflammatory cytokines. Northern blot analysis of total RNA from lung tissue indicated that inoculated pigs had increased concentrations of interleukin (IL)-1β, IL-1α, and IL-8; tumor necrosis factor messenger RNA concentration was not increased.

Conclusions—Endotracheal inoculation withA pleuropneumoniaerapidly and consistently induced diffuse bilateral pneumonia; thus, this method may be useful for the study of acute pathophysiologic changes associated with bacterial pneumonia and may provide an experimental model for testing modalities for prevention and treatment of this and other respiratory tract diseases of pigs. (Am J Vet Res2000;61:684–690)
Use of repetitive sequence-based polymerase chain reaction for molecular epidemiologic analysis of Streptococcus equi subspecies equi
Authors: Al-Ghamdi Ghanem M. , Kapur Vivek , Ames Trevor R. , Timoney John F. , Love Daria N. , Mellencamp Martha A.
Published: December 2005

Objective—To determine whether repetitive
sequence-based polymerase chain reaction (rep-PCR)
could be used to differentiate Streptococcus equi isolates,
to examine S equi isolates from throughout the
world, and to determine whether a horse had > 1 subtype
of S equi during an outbreak of disease.

Sample Population—An initial group of 32
S equi isolates, 63 S equi isolates from various geographic
areas, and 17 S equi isolates obtained during
outbreaks of disease.

Procedure—An aliquot of S equi genomic DNA was
amplified, using enterobacterial repetitive intergenic
consensus primers. Gel electrophoresis was performed
on 1.5% agarose gels, and a computed-assisted
program was used to compare rep-PCR results.

Results—Use of these primers to analyze 100 ng of
S equi genomic DNA resulted in patterns of 6 to 14
bands. The 32 initial isolates were separated into 7 rep-
PCR subtypes. There were 30 rep-PCR subtypes found
among 29 S equi isolates obtained from Minnesota,
Michigan, Canada, and Australia and 34 S equi isolates
obtained from Kentucky and other sources.
Furthermore, the same clone was identified in several
horses during an outbreak of disease. Infected horses
on the same farm all had a single clone of S equi.

Conclusion and Clinical Relevance—Analysis of
these results suggests that rep-PCR is useful for
delineating S equi into rep-PCR subtypes. Results
revealed that isolates with the same geographic
source or similar date of collection did not always
have the same rep-PCR subtype. A single clone of
S equi usually predominated during an outbreak of
disease. (Am J Vet Res 2000;61:699–705)
Concentrations of substance P and prostaglandin E2 in synovial fluid of normal and abnormal joints of horses
Authors: Kirker-Head Carl A. , Chandna V. K. , Agarwal R. K. , Morris Elisabeth A. , Tidwell Amy , O'Callaghan Michael W. , Rand William , Kumar M. S. A.
Published: December 2005

Objective—To correlate substance P content of synovial fluid with prostaglandin E2content, radiographic evidence of joint abnormality, and anatomic location of the joint for normal and osteoarthritic joints of horses.

Sample Population—Synovial fluid from 46 normal joints in 21 horses and 16 osteoarthritic joints in 10 horses.

Procedure—Normal and osteoarthritic joints were identified by clinical and radiographic examination, by response to nerve blocks, during scintigraphy or surgery, or by clinicopathologic evaluation. Substance P and prostaglandin E2contents of synovial fluid were determined by radioimmunoassay. Radiographs of joints were assigned a numeric score reflecting severity of lesions. Joints were assigned a numeric score reflecting anatomic location.

Results—Median concentrations of substance P and prostaglandin E2 were significantly increased in osteoarthritic joints, compared with normal joints. A significant correlation was found between concentrations of substance P and prostaglandin E2in synovial fluid, but a correlation was not detected between substance P concentration in synovial fluid and anatomic location of the joint or between radiographic scores of osteoarthritic joints and concentrations of substance P or prostaglandin E2.

Conclusions and Clinical Relevance—A correlation existed between concentrations of substance P and prostaglandin E2in synovial fluid obtained from normal and osteoarthritic joints. However, content of substance P in synovial fluid cannot be predicted by the radiographic appearance of the joint or its anatomic location. Substance P and prostaglandin E2may share an important and related role in the etiopathogenesis of osteoarthritis, lending credence to the importance of neurogenic inflammation in horses. (Am J Vet Res2000;61: 714–718)
Cardiac output measured by lithium dilution, thermodilution, and transesophageal Doppler echocardiography in anesthetized horses
Authors: Linton Robert A. , Young Lesley E. , Marlin David J. , Blissitt Karen J. , Brearley Jackie C. , Jonas Max M. , O'Brien Terry K. , Linton Nick W. , Band David M. , Hollingworth Chris , Jones Ronald S.
Published: December 2005

Objective—To assess the suitability of lithium dilution as a method for measuring cardiac output in anesthetized horses, compared with thermodilution and transesophageal Doppler echocardiography.

Animals—6 horses (3 Thoroughbreds, 3 crossbreeds).

Procedure—Cardiac output was measured in 6 anesthetized horses as lithium dilution cardiac output (LiDCO), thermodilution cardiac output (TDCO), and transesophageal Doppler echocardiographic cardiac output (DopplerCO). For the LiDCO measurements, lithium chloride was administered IV, and cardiac output was derived from the arterial lithium dilution curve. Sodium nitroprusside, phenylephrine hydrochloride, and dobutamine hydrochloride were used to alter cardiac output. Experiments were divided into 4 periods. During each period, 3 LiDCO measurements, 3 DopplerCO measurements, and 3 sets of 3 TDCO measurements were obtained.

Results—70 comparisons were made between LiDCO, DopplerCO, and triplicate TDCO measurements over a range of 10 to 43 L/min. The mean (± SD) of the differences of LiDCO – TDCO was –0.86 ± 2.80 L/min; LiDCO = –1.90 + 1.05 TDCO (r= 0.94). The mean of the differences of DopplerCO – TDCO was 1.82 ± 2.67 L/min; DopplerCO = 2.36 + 0.98 TDCO (r= 0.94). The mean of the differences of LiDCO – DopplerCO was –2.68 ± 3.01 L/min; LiDCO = –2.53 + 0.99 DopplerCO (r= 0.93).

Conclusions and Clinical Relevance—These results indicate that lithium dilution is a suitable method for measuring cardiac output in horses. As well as being accurate, it avoids the need for pulmonary artery catheterization and is quick and safe to use. Monitoring cardiac output during anesthesia in horses may help reduce the high anesthetic mortality in this species. (Am J Vet Res2000;61:731–737)
Passive transfer of colostral immunoglobulin G in neonatal llamas and alpacas
Authors: Weaver Dusty M. , Tyler Jeff W. , Scott Michael A. , Wallace Laurie M. , Marion Richard S. , Holle Julie M.
Published: December 2005

Objective—To evaluate precolostral hypogammaglobulinemia in neonatal llamas and alpacas, to determine when postcolostral peak serum IgG concentrations develop, to determine whether differences in postcolostral serum IgG concentrations between llamas and alpacas exist, and to determine postcolostral half-life of serum IgG in llamas and alpacas.

Design—Prospective observational study.

Animals—29 llama and 10 alpaca crias.

Procedure—Blood samples were collected prior to suckling and on days 1, 2, and 3 after parturition and analyzed for serum IgG concentration by use of a commercial radial immunodiffusion assay. Additional samples were collected on days 8, 13, and 18 from 8 crias to determine mean half-life of IgG.

Results—Llamas and alpacas are born severely hypogammaglobulinemic. Mean serum IgG concentrations for day-1, -2, and -3 samples for llamas were 1,578 mg/dl, 1,579 mg/dl, and 1,401 mg/dl, respectively, and for alpacas were 2,024 mg/dl, 1,806 mg/dl, and 1,669 mg/dl, respectively. Peak serum immunoglobulin concentration developed between days 1 and 2. Mean half-life of IgG for all crias was 15.7 days.

Conclusions and Clinical Relevance—Although increased mortality has been linked to failure of passive transfer, it is clearly possible to raise crias that have low serum immunoglobulin concentrations. Llamas and alpacas do not differ significantly with respect to immunoglobulin absorption or IgG concentration in neonates. The optimal sampling time for passive transfer status is between 1 and 2 days. (Am J Vet Res2000;61:738–741)
Cytokine secretion by peripheral blood mononuclear cells from cows infected with Mycobacterium paratuberculosis
Authors: Stabel Judith R.
Published: December 2005

Objective—To compare cytokine secretion patterns of peripheral blood mononuclear cells (PBMC) from healthy cows and cows subclinically and clinically infected withMycobacterium paratuberculosis.

Animals—5 noninfected cows, 6 cows with subclinical paratuberculosis, and 4 cows with clinical paratuberculosis.

Procedure—PBMC were isolated, and concentrations or activities of secreted interleukin (IL)-1, IL-2, IL- 6, tumor necrosis factor (TNF), and interferon−γ (IFN-γ) were measured after in vitro stimulation of cells with concanavalin A (ConA), lipopolysaccharide (LPS), or a whole-cell sonicate ofM paratuberculosis(MpS). Proliferative responses of PBMC were also determined after stimulation with ConA, phytohemagglutinin, pokeweed mitogen (PWM), or MpS.

Results—After stimulation with ConA, cells from subclinically infected cows secreted significantly more, and cells from clinically infected cows secreted significantly less, IFN-γ, compared with cells from control cows. Cells from cows with subclinical paratuberculosis produced significantly more TNF and IFN-γ in response to MpS than cells from the other 2 groups. Stimulation of PBMC from subclinically infected cows with ConA or MpS resulted in significantly higher proliferative responses, compared with cells from control and clinically infected cows. In contrast, clinically infected cows had significantly higher proliferative responses to PWM than cells from the other 2 groups.

Conclusions and Clinical Relevance—A decrease in T-cell responses to mitogens or MpS was observed in cows clinically infected withM paratuberculosis, compared with subclinically infected cows, suggesting that activated T cells may delay the progression of paratuberculosis. (Am J Vet Res2000;61:754–760)
Pharmacokinetics and pharmacodynamics of terbutaline in healthy horses
Authors: Törneke M. Karolina , Ingvast-Larsson J. Carina , Johansson Jenny M. , Appelgren Lars-Erik
Published: December 2005

Objective—To determine pharmacokinetics of terbutaline
in healthy horses and to relate serum terbutaline
concentrations with the drug’s pharmacodynamic
effects.

Animals—6 healthy horses.

Procedure—Horses were given terbutaline IV
(10 µg/kg of body weight) and, 1 week later, PO (100
µg/kg). Responses to drug administration (eg, heart
rate and serum lactate concentration) were measured.
Serum terbutaline concentration was measured by
means of gas chromatography with mass spectrometry.
Protein binding was determined in vitro.

Results—Following IV administration, median maximum
serum terbutaline concentration and mean
residence time were 9.3 ng/ml and 30 minutes,
respectively. Bioavailability following oral administration
was < 1%. All horses developed sweating,
trembling, excitement, and tachycardia during IV
infusion. The 2 horses with the highest serum terbutaline
concentrations developed severe tachycardia
and CNS stimulation; 30 minutes after the IV infusion
was completed, they were hyperventilating and
lethargic. Heart rate and serum lactate concentration
increased as serum terbutaline concentration
increased.

Conclusions and Clinical Relevance—Results indicated
that terbutaline is rapidly cleared from the
bloodstream following IV administration to horses,
suggesting that continuous IV infusion would be
needed to maintain therapeutic serum concentrations.
Oral administration of terbutaline to horses is
not practical because of the low bioavailability.
(Am J Vet Res 2000;61:761–765)
Bacterial contamination of suction tips used during surgical procedures performed on dogs and cats
Authors: Sturgeon Catherine , Lamport Anne I. , Lloyd David H. , Muir Peter
Published: December 2005

Objective—To determine prevalence of bacterial contamination of surgical suction tips.

Sample Population—Surgical tips used during 44 surgical procedures performed on 42 dogs and 2 cats.

Procedure—Surgical procedures were classified into 1 of 3 categories according to degree of bacterial contamination of the surgical site (clean, clean-contaminated, contaminated). Two sets of suction apparatuses were used for test and control suction tips. Test tips were used normally to suction blood and fluid, whereas control tips were placed on the surgical drapes but not in the surgical wound. Suction tips were collected aseptically and placed into thioglycolate broth tubes for qualitative aerobic and anaerobic bacterial culture at the end of each procedure.

Results—Test and control suction tips were contaminated with bacteria during 30 of 44 (68%) procedures.Staphylococcusspp were the predominant bacteria in tips used during clean and clean-contaminated surgeries. When surgery was performed on clean-contaminated or contaminated wounds, prevalence of isolation of other bacteria such asPseudomonasspp,Streptococcusspp, andEscherichia colifrom both test and control suction tips was higher than for clean wounds. Mean time of procedures during which both test and control suction tips became contaminated was not significantly different from time of procedures during which neither tip became contaminated.

Conclusion and Clinical Relevance—Surgical suction tips often become contaminated during standard veterinary surgical procedures. The risk of wound infection after surgery may be influenced by bacterial contamination of surgical suction tips. (Am J Vet Res2000;61:779–783)
Use of cis-bis-neodecanoato-trans-R,R-1, 2-diaminocyclohexane platinum (II), a liposomal cisplatin analogue, in cats with oral squamous cell carcinoma
Authors: Fox Leslie E. , Rosenthal Robert C. , King Robert R. , Levine Paula B. , Vail David M. , Helfand Stuart C. , MacEwen E. Gregory , Perez-Soler Roman , Calderwood-Mays Maron , Kurzman Ilene D.
Published: December 2005

Objective—To determine clinical response and toxic effects of cis-bis-neodecanoato-trans-R,R-1,2- diaminocyclohexane platinum (II) (L-NDDP) administered IV at escalating doses to cats with oral squamous cell carcinoma (SCC).

Animals—18 cats with oral SCC.

Procedure—Cats that failed to respond to conventional treatment or had nonresectable tumors were included. Data included a CBC, serum biochemical analyses, urinalysis, cytologic examination of a fineneedle aspirate of enlarged lymph nodes, and thoracic and oral radiographs for clinical staging. A starting dose (75 to 100 mg/m2of L-NDDP) was administered IV. At 21-day intervals, subsequent doses increased by the rate of 5 or 10 mg/m2. Response was evaluated every 21 days by tumor measurement and thoracic radiography. Quality of life was assessed by owners, using a performance status questionnaire.

Results—On average, cats received 2 treatments. Toxicoses included an intermittent, acute anaphylactoid- parasympathomimetic reaction, lethargy or sedation (≤ 24 hours), inappetence or signs of depression (≤ 72 hours), mild to moderate increase in hepatic enzyme activity, and melena. Pulmonary, renal, or hematopoietic abnormalities were not evident. Performance status surveys indicated normal behavior and grooming or decreased activity and self-care (19/20 assessments), ate well with or without assistance (15/20), and did not lose weight (15/20). Median survival time was 59.8 days (mean, 54.1 days).

Conclusions and Clinical Relevance—L-NDDP was ineffective for treatment of cats with oral SCC. None of the cats had a complete or partial remission. Acute toxicoses and poor therapeutic response limit therapeutic usefulness of L-NDDP in cats, unless dosage, frequency, and administration procedures can be improved. (Am J Vet Res2000;61: 791–795)
Effects of dietary fructooligosaccharide on selected bacterial populations in feces of dogs
Authors: Willard Michael D. , Simpson R. Bruce , Cohen Noah D. , Clancy Julianne S.
Published: December 2005

Objective—To evaluate fecal concentrations of selected genera of colonic bacteria in healthy dogs, and to investigate effects of dietary fructooligosaccharides (FOS) on those bacterial populations.

Animals—6 healthy adult Beagles.

Procedure—Dogs were randomly assigned to 2 groups of 3 and fed an unsupplemented diet for 370 days. After 88 days, fecal samples were collected. Another fecal sample was collected from each dog 282 days later. Group A then received a diet supplemented with FOS, and group B continued to receive the unsupplemented diet. Twenty-eight to 29 days later, fecal samples were collected. Diets were switched between groups, and fecal samples were collected 31 and 87 days later. Concentrations ofBifidobacteriumspp,Lactobacillusspp,Clostridiumspp,Bacteroidesspp, andEscherichia coliin freshly collected feces were determined. Effects of diet and time on bacterial concentrations were compared between groups.

Results—Bifidobacteriumspp andLactobacillusspp were inconsistently isolated from feces of dogs fed either diet. Sequence of diet significantly affected number ofBacteroidesspp subsequently isolated from feces, but diet had no effect on numbers ofClostridiumspp orE coli.

Conclusions and Clinical Relevance—Some genera of bacteria (eg,Bifidobacterium) believed to be common components of colonic microflora may be only sporadically isolated from feces of healthy dogs. This deviation from expected fecal flora may have implications for the effectiveness of supplementing diets with prebiotics. (Am J Vet Res2000;61: 820–825)
In vitro evaluation of intraluminal factors that may alter intestinal permeability in ponies with carbohydrate-induced laminitis
Authors: Weiss Douglas J. , Evanson Oral A. , Green Benedict T. , Brown David R.
Published: December 2005

Objectives—To study the in vitro effects of cecal contents incubated with corn starch on colonic permeability in horses.

Animals—4 healthy adult ponies.

Procedure—Mucosal specimens were obtained from the right ventral colon and mounted in Ussing chambers. Changes in short circuit current, conductance, and large-molecule permeability in response to addition of cecal contents and cecal contents incubated with corn starch were evaluated for 120 minutes.

Results—Incubation of cecal contents with corn starch for 8 hours resulted in a decrease in cecal content pH and an increase in lactic acid concentration. These changes were similar to those reported in vivo for ponies given corn starch. Exposure of colonic mucosa to cecal contents incubated with corn starch resulted in an increase in tissue conductance and permeability of technetium Tc 99m pentetate, compared with mucosa exposed to cecal contents alone.

Conclusions and Clinical Relevance—In vitro exposure of colonic mucosa to cecal contents incubated with starch resulted in increased paracellular permeability. Fermentation of excessive amounts of carbohydrate in the intestinal lumen of horses may directly induce increased intestinal permeability associated with carbohydrate-induced laminitis. (Am J Vet Res2000;61:858–861)
Identification of tuberculosis in cattle slaughtered in Mexico
Authors: Milian-Suazo Feliciano , Salman M. D. , Ramirez Carolina , Payeur Janet B. , Rhyan Jack C. , Santillan Marco
Published: December 2005

Objectives—To determine epidemiologic factors
associated with tuberculosis (TB) in dairy cattle
slaughtered in 6 important regions for milk production
in Mexico.

Animals—2,500 cattle.

Procedure—Tissue specimens with lesions typical of
TB were obtained during routine inspection of carcasses
at abbatoirs between July 1996 and January
1997. Infection with Mycobacterium organisms was
confirmed by histologic examination and bacteriologic
culture. Species identification was made by use of
selective growth medium, conventional biochemical
tests, and radiometric procedures. Epidemiologic
information for affected cattle was obtained by personal
interviews with cattle dealers and owners.

Results—400 (16%) of 2,500 cattle carcasses had
gross lesions typical of TB. Of the 400 infected cattle,
336 (84%) had lesions in ≥ 1 lymph node. Infection
was confirmed in 87% of cattle with gross lesions by
histologic examination, in 77% by bacteriologic culture
at a laboratory in the United States, and in 59% by
bacteriologic culture at a laboratory in Mexico. Most
cattle were adult females in fair to good body condition
that came from large herds (> 500 cattle) and
were not included in the Mexican TB control program.

Conclusions and Clinical Relevance—Mean prevalence
of lesions typical of TB in dairy cattle at 6 locations
in Mexico was 16%. Mycobacterium infection
was confirmed by various techniques in most lesions.
Recognition of typical gross lesions at slaughter may
expedite TB control procedures. (Am J Vet Res 2000;
61:86–89)
Effects of an extract of Serenoa repens on dogs with hyperplasia of the prostate gland
Authors: Barsanti Jeanne A. , Finco Delmar R. , Mahaffey Mary M. , Fayrer-Hosken Richard A. , Crowell Wayne A. , Thompson Frederick N. , Shotts Emmett B.
Published: December 2005

Objective—To determine effects of an extract ofSerenoa repenson dogs with prostatic hyperplasia.

Animals—20 mature male dogs with benign prostatic hyperplasia.

Procedure—Dogs were assigned to 3 comparable groups on the basis of prostatic volume per kg of body weight and degree of prostatic hyperplasia determined histologically. Dogs in 2 groups were treated for 91 days (8 received 500 mg, PO, q 8 h [1,500 mg/d], and 6 received 100 mg, PO, q 8 h [300 mg/d]). The control group of 6 dogs did not receive medication. Effects of treatment on prostatic volume, prostatic weight, prostatic histologic characteristics, radiographic and ultrasonographic assessment of prostatic size, results of CBC, serum biochemical analyses, and urinalysis, serum testosterone concentration, and semen characteristics were determined. At the termination of the study, all dogs were euthanatized, and necropsies were performed. Investigators conducting tests and interpreting results were not aware of treatment group of each dog.

Results—Treatment did not affect prostatic weight, prostatic volume, or prostatic histologic scores, libido, semen characteristics, radiographs of the caudal portion of the abdomen, prostatic ultrasonographs, or serum testosterone concentrations. Results of CBC, serum biochemical analyses or urinalysis, and body weights did not change during treatment.

Conclusions and Clinical Relevance—Treatment with an extract ofS repensfor 91 days did not significantly affect the prostate gland of dogs. Adverse effects were not evident. Although products containing extracts ofS repensare widely advertised for men with prostatic hyperplasia, beneficial or harmful effects of this plant extract were not found in dogs with prostatic hyperplasia. (Am J Vet Res2000;61:880–885)
Effects of intranasal inoculation of porcine reproductive and respiratory syndrome virus, Bordetella bronchiseptica, or a combination of both organisms in pigs
Authors: Brockmeier Susan L. , Palmer Mitchell V. , Bolin Steven R.
Published: December 2005

Objective—To examine effects of co-infection with porcine reproductive and respiratory syndrome virus (PRRSV) andBordetella bronchisepticain pigs.

Animals—Forty 3-week-old pigs.

Procedure—30 pigs (10 pigs/group) were inoculated with PRRSV,B bronchiseptica, or both. Ten noninoculated pigs were control animals.

Results—Clinical signs, febrile response, and decreased weight gain were most severe in the group inoculated with both organisms. The PRRSV was isolated from all pigs in both groups inoculated with virus. All pigs in both groups that received PRRSV had gross and microscopic lesions consistent with interstitial pneumonia.Bordetella bronchisepticawas cultured from all pigs in both groups inoculated with that bacterium. Colonization of anatomic sites byB bronchisepticawas comparable between both groups. Pigs in the group that received onlyB bronchisepticalacked gross or microscopic lung lesions, andB bronchisepticawas not isolated from lung tissue. In the group inoculated withB bronchisepticaand PRRSV, 3 of 5 pigs 10 days after inoculation and 5 of 5 pigs 21 days after inoculation had gross and microscopic lesions consistent with bacterial bronchopneumonia, andB bronchisepticawas isolated from the lungs of 7 of those 10 pigs.

Conclusions and Clinical Relevance—Clinical disease was exacerbated in co-infected pigs, including an increased febrile response, decreased weight gain, andB bronchiseptica-induced pneumonia.Bordetella bronchisepticaand PRRSV may circulate in a herd and cause subclinical infections. Therefore, co-infection with these organisms may cause clinical respiratory tract disease and leave pigs more susceptible to subsequent infection with opportunistic bacteria. (Am J Vet Res2000;61:892–899)
Comparison of Northern blot hybridization and a reverse transcriptase-polymerase chain reaction technique for measurement of mRNA expression of metalloproteinases and matrix components in articular cartilage and synovial membrane from horses with osteoarthritis
Authors: Fehr Joanne E. , Trotter Gayle W. , Oxford Julia T. , Hart David A.
Published: December 2005

Objective—To determine relative amounts of mRNA expression of aggrecan, type-II collagen, matrix metalloproteinase (MMP) 1, and MMP3 in articular cartilage and synovial membrane samples from healthy equine joints and joints with osteoarthritis (OA) and to compare results of Northern blot hybridization with results of a reverse transcriptase-polymerase chain reaction (RT-PCR) assay.

Sample Population—Articular cartilage samples from 8 pairs of joints (1 with OA and 1 healthy) from 6 horses and synovial membrane samples from 6 pairs of joints from 5 horses.

Procedure—RNA was extracted from samples by use of a modified Trizol procedure. Northern blot hybridization and the RT-PCR assay were performed; results were quantitated by use of glyceraldehyde 3- phosphate dehydrogenase as an internal standard.

Results—Articular cartilage samples from joints with mild or moderate OA yielded less total RNA than samples from joints with severe OA. Northern blot hybridization indicated that type-II collagen mRNA expression in articular cartilage samples from joints with OA was significantly greater than expression in samples from healthy joints. The RT-PCR assay identified low levels of MMP3 mRNA expression in 4 of 8 sets of articular cartilage samples and 4 of 6 sets of synovial membrane samples, whereas Northern blot hybridization identified MMP3 mRNA expression in only 1 of 6 sets of articular cartilage samples and 1 of 6 sets of synovial membrane samples.

Conclusions—A RT-PCR assay is more sensitive than Northern blot hybridization for detection of MMP3 mRNA expression in articular cartilage and synovial membrane and requires smaller samples. (Am J Vet Res2000;61:900–905)
Comparison of the in vitro antiproliferative effects of five immunosuppressive drugs on lymphocytes in whole blood from cats
Authors: Kyles Andrew E. , Gregory Clare R. , Craigmill Arthur L.
Published: December 2005

Objective—To compare the in vitro imMunosuppressive effects of cyclosporine and 4 novel immunosuppressive drugs on lymphocytes in whole blood collected from healthy cats.

Sample Population—Whole blood samples collected from 10 healthy adult domestic shorthair cats.

Procedure—Mitogen-stimulated lymphocyte proliferation in whole blood incubated with and without various concentrations of cyclosporine, tacrolimus, sirolimus, mycophenolic acid (MPA), or A771726 was measured by use of [3H]thymidine incorporation. Drug concentrations that resulted in a 50% inhibition of mitogen-induced proliferation (IC50) were calculated. Lymphocyte viability was determined by use of the trypan blue dye exclusion method.

Results—An obvious dose-response relationship for the antiproliferative effects of each drug was detected. Mean IC50 determined with concanavalin A was 46 nMfor cyclosporine, 9 nMfor tacrolimus, 12 nMfor sirolimus, 16 nMfor MPA, and 30 mMfor A771726, whereas with pokeweed mitogen, mean IC50was 33 nMfor cyclosporine, 5 nMfor tacrolimus, 15 nMfor sirolimus, 14 nMfor mycophenolic acid, and 25 mMfor A771726. Mitogen-stimulated and nonstimulated lymphocytes remained viable, regardless of drug evaluated.

Conclusions and Clinical Relevance—Tacrolimus, sirolimus, MPA, and A771726 inhibited in vitro mitogen- stimulated proliferation of feline lymphocytes in a dose-dependent manner. These novel immunosuppressive drugs may be useful for management of immune-mediated inflamMatory diseases and prevention and treatment of rejection in cats that undergo organ transplantation. (Am J Vet Res2000;61: 906–909)
Phagocytosis and killing of Staphylococcus aureus by bovine neutrophils after priming by tumor necrosis factor-α and the des-arginine derivative of C5a
Authors: Rainard Pascal , Riollet Céline , Poutrel Bernard , Paape Max J.
Published: December 2005

Objectives—To evaluate effects of proinflammatory mediators on phagocytosis and killing ofStaphylococcus aureus, the oxidative burst (OB), and expression of receptors for opsonins by bovine neutrophils.

Sample Population—Neutrophils from 10 cattle.

Procedure—Neutrophils were primed with recombinant bovine tumor necrosis factor-α (TNF-α) or the des-arginine derivative of bovine C5a (C5adesArg) and mixed withS aureus. Phagocytosis and OB were measured by use of flow cytometry. Rate of phagocytosis and intracellular killing were evaluated. Expression of receptors for immunoglobulins and the C3bi fragment of complement were estimated by use of flow cytometry.

Results—Priming of neutrophils by TNF-α improved phagocytosis ofS aureuswith a concentrationdependent effect. Phagocytosis of preopsonized washed bacteria was increased by activation of neutrophils with C5adesArg. Phagocytosis was optimal when neutrophils primed with TNF-α were activated with C5adesArg. The OB of phagocytizing neutrophils was highest when TNF-α and C5adesArgwere used in combination. Bactericidal activity of neutrophils was stimulated by priming with TNF-α or C5adesArg. Binding of bovine IgM or IgG2to bovine neutrophils was not stimulated by TNF-α, C5adesArg, or both, and aggregated IgG1 did not bind to neutrophils regardless of their activation state. Both TNF-α and C5adesArgincreased expression of β2 integrins (CD18), with the highest expression when they were used in combination.

Conclusions and Clinical Relevance—The mediators TNF-α and C5adesArgstimulated phagocytic killing by neutrophils and potentiated each other when used at suboptimal concentrations. Bovine neutrophils have enhanced bactericidal activities at inflammatory sites when TNF-α, C5adesArg, or both are produced locally. (Am J Vet Res2000;61:951–959)
Effects of exercise intensity and duration on plasma β-endorphin concentrations in horses
Authors: Mehl Margo L. , Schott Harold C. , Sarkar Dipak K. , Bayly Warwick M.
Published: December 2005

Objective—To determine the relationship between
plasma β-endorphin (EN) concentrations and exercise
intensity and duration in horses.

Animals—8 mares with a mean age of 6 years
(range, 3 to 13 years) and mean body weight of 450 kg.

Procedure—Horses were exercised for 20 minutes
at 60% of maximal oxygen consumption (O2max)
and to fatigue at 95% O2max. Plasma EN concentrations
were determined before exercise, after a 10-
minute warmup period, after 5, 10, 15, and 20 minutes
at 60% O2max or at the point of fatigue (95%
O2max), and at regular intervals after exercise.
Glucose concentrations were determined at the
same times EN concentrations were measured.
Plasma lactate concentration was measured 5 minutes
after exercise.

Results—Maximum EN values were recorded 0 to
45 minutes after horses completed each test.
Significant time and intensity effects on EN concentrations
were detected. Concentrations were significantly
higher following exercise at 95% O2max,
compared with those after 20 minutes of exercise at
60% O2max (605.2 ± 140.6 vs 312.3 ± 53.1 pg/ml).
Plasma EN concentration was not related to lactate
concentration and was significantly but weakly correlated
with glucose concentration for exercise at
both intensities (r = 0.21 and 0.30 for 60 and 95%
O2max, respectively).

Conclusions and Clinical Relevance—A critical
exercise threshold exists for EN concentration in
horses, which is 60% O2max or less and is related
to exercise intensity and duration. Even under conditions
of controlled exercise there may be considerable
differences in EN concentrations between
horses. This makes the value of comparing horses
on the basis of their EN concentration questionable.
(Am J Vet Res 2000;61:969–973)
Additional kinematic variables to describe differences in the trot between clinically normal dogs and dogs with hip dysplasia
Authors: Poy Nancy S. J. , DeCamp Charles E. , Bennett Russell L. , Hauptman Joe G.
Published: December 2005

Objective—To describe the abnormal gait of dogs with hip dysplasia by use of kinematic gait analysis.

Animals—19 large-breed dogs with moderate to severe clinical and radiographic evidence of hip dysplasia and 10 clinically normal dogs (controls).

Procedure—Kinematic and force plate data were collected, and degree of coxofemoral joint abductionadduction, mediolateral foot movement, distance between hind feet, maximum hind foot elevation, mediolateral pelvic movement, and coxofemoral joint angular acceleration were calculated. Essential Fourier coefficients were determined and used to reconstruct mean angular acceleration curves. Fourier coefficients and foot and pelvic movement data were compared between groups.

Results—Dogs with hip dysplasia had a greater degree of coxofemoral joint adduction and range of abduction-adduction and greater lateral pelvic movement, compared with controls. Foot movement variables did not differ significantly between groups. Coxofemoral joint angular acceleration was greater in the middle to end of the stance phase, whereas deceleration was greater in the late stance to early swing phase and middle to end of the swing phase in dogs with hip dysplasia, compared with controls.

Conclusions and Clinical Relevance—Differences in degree of coxofemoral joint abduction-adduction, amount of mediolateral pelvic movement, and coxofemoral joint angular acceleration between clinically normal dogs and dogs with hip dysplasia may indicate a compensation in gait of affected dogs as a result of discomfort or biomechanical effects attributable to hip dysplasia and degenerative joint disease. Information gained from kinematic and kinetic gait analyses may be useful in evaluating treatments for hip dysplasia in dogs. (Am J Vet Res2000;61:974–978)
Effects of subclinical pregnancy toxemia on immune responses in sheep
Authors: Lacetera Nicola , Bernabucci Umberto , Ronchi Bruno , Nardone Alessandro
Published: December 2005

Objective—To determine the effects of moderate
feed restriction, single or twin pregnancy, and subclinical
pregnancy toxemia (PT) on immune responses
of ewes.

Animals—16 Sardinian ewes.

Procedure—Six weeks before lambing, ewes were
assigned to 1 of 2 groups (n = 8/group) matched for
number of fetuses, body condition score, and plasma
glucose, non-esterified fatty acids (NEFA), and β-
hydroxybutyrate (BHBA) concentrations, and feed
intake was restricted for 1 of the groups. Cell-mediated
immunity was evaluated in vivo and in vitro.
Humoral immunity was evaluated in vivo by determining
production of IgG antibodies against keyhole
limpet hemocyanin (KLH).

Results—Four ewes developed subclinical PT (plasma
BHBA concentration > 0.86 mmol/L without any
clinical signs of disease). Whether feed was restricted
and type of pregnancy (single vs twin) did not have
any significant effects on cell-mediated and humoral
immune responses. Ewes with subclinical PT had significantly
lower in vitro proliferation of phytohemagglutinin-
stimulated peripheral blood mononuclear
cells and significantly lower values for KLH-specific
IgG than did healthy ewes. Plasma BHBA and NEFA
concentrations were negatively correlated with in
vitro proliferation of peripheral blood mononuclear
cells; plasma NEFA concentration was negatively correlated
with values for KLH-specific IgG.

Conclusions and Clinical Relevance—Results suggest
that subclinical PT may be associated with impairments
in cell-mediated and humoral immune responses
in sheep. Am J Vet Res 2001;62:1020–1024)
Effects of ring diameter and wire tension on the axial biomechanics of four-ring circular external skeletal fixator constructs
Authors: Cross Alan R. , Lewis Daniel D. , Murphy Scott T. , Rigaud Steve , Madison John B. , Kehoe Martha M. , Rapoff Andrew J.
Published: December 2005

Objective—To determine relative effects of ring diameter and wire tension on axial biomechanical properties of 4-ring circular external skeletal fixator constructs.

Sample Population—4-ring circular external skeletal fixator constructs and artificial bone models.

Procedure—4-ring constructs were assembled, using 50-, 66-, 84-, or 118-mm-diameter rings. Two 1.6-mm-diameter fixation wires were attached to opposing surfaces of each ring at intersection angles of 90o and placed through a gap-fracture bone model. Three examples of each construct were loaded in axial compression at 7 N/s to a maximum load of 400 N at each of 4 wire tensions (0, 30, 60, and 90 kg). Response variables were determined from resulting load-displacement curves (construct stiffness, load at 1 mm of displacement, displacement at 400 N).

Results—Ring diameter and wire tension had a significant effect on all response variables and had a significant interaction for construct stiffness and displacement at 400 N. Significant differences within all response variables were seen among all 4 ring diameters and all 4 wire tensions. As ring diameter increased, effect of increasing wire tension on gap stiffness and gap displacement at 400 N decreased. Ring diameter had a greater effect than wire tension on all response variables.

Conclusions and Clinical Relevance—Although effects of wire tension decrease as ring diameter increases, placing tension on wires in larger ring constructs is important because these constructs are inherently less stiff. The differential contribution of ring diameter, wire tension, and their interactions must be considered when using circular external skeletal fixators. (Am J Vet Res2001;62:1025–1030)
Evaluation of phagocytosis, bactericidal activity, and production of superoxide anion, nitric oxide, and tumor necrosis factor-α in Kupffer cells of neonatal pigs
Authors: Akunda J. Kinyamu , Ahrens Franklin A. , Kramer Theodore T.
Published: December 2005

Objective—To evaluate the activity of Kupffer cells (KC) of control neonatal pigs and neonatal pigs treated with endotoxin and to compare activity of KC with that of pulmonary alveolar macrophages (PAM).

Sample Population—Kupffer cells and PAM obtained from 24 neonatal pigs (7 to 10 days old).

Procedure—Pairs (n = 7) of littermates served as treated (lipopolysaccharide [LPS]) or untreated pigs. Pigs were euthanatized 24 hours after treatment, and cells were isolated. Cells were obtained from 10 other neonatal pigs for other assays. Functional activity of cells was evaluated by use of in vitro assays to evaluate bactericidal activity, phagocytosis, and production of superoxide anion (SOA), nitric oxide (NO), and tumor necrosis factor-α (TNF-α). Each assay was repeated on cells obtained from 4 to 6 pigs.

Results—Phagocytic activity was similar in KC and PAM, but bactericidal activity and production of SOA and TNF-α was lower in KC. Neither KC nor PAM produced NO in response to LPS stimulation. Phagocytosis, bactericidal activity, and production of SOA were enhanced for KC obtained from neonatal pigs treated with LPS. The PAM from LPS-treated neonatal pigs had similar bactericidal activity to PAM obtained from untreated pigs.

Conclusions and Clinical Relevance—Functional capacity of KC is affected by endotoxin. This provides additional information of the role the liver plays in immune surveillance. In addition, the response of KC in neonatal pigs exposed to endotoxin is of value for understanding gram-negative bacterial sepsis, which is a major cause of mortality in neonatal pigs. (Am J Vet Res2001;62:1040–1045)
Metabolic changes and induction of hepatic lipidosis during feed restriction in llamas
Authors: Tornquist Susan J. , Cebra Christopher K. , Van Saun Robert J. , Smith Bradford B. , Mattoon John S.
Published: December 2005

Objectives—To determine whether feed restriction induces hepatic lipidosis (HL) in llamas and to evaluate the metabolic changes that develop during feed restriction.

Animals—8 healthy adult female llamas.

Procedure—Llamas were fed grass hay at a rate of 0.25% of their body weight per day for 13 to 28 days. Llamas were monitored by use of clinical observation, serum biochemical analyses, and ultrasound-guided liver biopsies.

Results—All 8 llamas lost weight and mobilized fat. Five llamas developed HL, including 4 that were nursing crias. During the period of feed restriction, mean serum concentration of bile acids and activities of aspartate aminotransferase (AST), sorbitol dehydrogenase (SDH), and γ-glutamyl transferase (GGT) were significantly higher in llamas that developed HL, compared with llamas that did not. Mean insulin-to-cortisol concentration ratios were lower in llamas with HL before and up to 7 days of feed restriction, compared with those that did not develop HL.

Conclusions and Clinical Relevance—HL in llamas may be induced by severe feed restriction, particularly in the face of increased energy demand. Llamas with weight loss attributable to inadequate dietary intake may develop biochemical evidence of hepatopathy and HL. Increases in serum concentration of bile acids and activities of GGT, AST, and SDH may indicate the development of HL in llamas and identify affected animals for aggressive therapeutic intervention. (Am J Vet Res2001;62:1081–1087)