bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of foot-and-mouth disease virus-free regions by use of a standardized enzyme-linked immunoelectrotransfer blot assay
Authors: Bergmann Ingrid E. , Malirat Viviana , Dias Luis Eduardo , Dilandro Rosa
Published: January 2024

Objective

To assess the potential of a highly sensitive enzyme-linked immunoelectrotransfer blot (EITB) assay to monitor persistent foot-and-mouth disease (FMD) viral activity in a livestock population.

Design

Cattle sera were obtained in Uruguay in 1992, 2 years after the last outbreaks of FMD. Prevalence of antibodies, as assessed by the EITB assay and by the conventional immunodiffusion in agarose gel method (virus infection-associated antigen [VIAA] test), was correlated with occurrence of FMD.

Sample Population

A total of 2,194 serum samples were acquired from animals at different farms and were separated according to age: animals < and > 2 years old.

Procedure

Specific antibodies to replicating virus were detected by use of the EITB assay that utilizes a set of 5 bioengineered nonstructural antigens as serologic probes.

Results

EITB-positive reaction was restricted to sera from cattle in areas with the last outbreaks of FMD during 1989-1990, and to animals > 2 years old. All cattle sera from regions that were free of clinical FMD since (or prior to) 1989 were EITB negative. In contrast, use of the VIAA test yielded a rather homogeneous distribution of positive results when regions without FMD during the last 4 years preceding sample collection were compared with those affected during 1989-1990. VIAA test-positive reaction was also found in sera from animals born after the last FMD outbreak.

Conclusions

The EITB assay proved to be a sensitive, specific, safe, rapid, and economic tool for monitoring the progress of FMD eradication programs, mainly because it eliminated false-positive results from the VIAA test (Am J Vet Res 1996;57:972–974).
Comparison of media and sera used for in vitro culture of equine superficial digital flexor tendon explants
Authors: Riley Christopher B. , Archer F. Joy , Bailey Jeremy V.
Published: January 2024

Objective

To compare the effects of different commercial nutrient media and sera on protein synthesis and maintenance of cellular density in cultures of the equine superficial digital flexor tendon (SDFT).

Animals

8 healthy 2- to 4-year-old horses.

Procedure

First Dulbecco's modified Eagle's medium, Ham's F12 nutrient mixture, RPMI 1640 medium, minimum essential medium with Earle's salts, minimum essential medium with Hanks' salts, and a Dulbecco's modified Eagle's medium/Ham's F12 nutrient mixture with 10% fetal bovine serum (FBS) were compared. Then FBS, fetal equine serum, and donor horse serum, each at 5, 10, and 15% in RPMI 1640 medium, were compared. Explants were cultured in roller bottles at 37 C and aerated (50% O2/45% N2/5% CO2) daily. Rates of [3H]- proline incorporation were used as a measure of the rates of total protein and collagen synthesis on days 13 and 28. Matrix cellular density of explants at days 14 and 28 was measured by computerized image analysis.

Results

Equine SDFT explants were cultured in all media for up to 4 weeks. Proline incorporation was greatest in Ham's F12 nutrient mixture and in RPMI 1640 medium, with the concentration of proline in medium correlating to the in vitro response. Total proline incorporation was greater in 15% FBS than in 5 or 10% FBS. Other differences among sera were not detected. Matrix cell density in 15% donor horse serum was equivalent to that in uncultured controls and higher than that in most other sera at week 2.

Conclusion

The in vitro SDFT culture system described may be used in future studies to enhance knowledge of the biological and biochemical characteristics of intrinsic tendon healing. (Am J Vet Res 1996;57:1118–1123)
Reliability of carnitine concentrations measured in single postprandial urine samples from dogs
Authors: Sanderson Sherry , Osborne Carl , Lulich Jody , Pierpont Mary Ella , Gross Kathy , Ogburn Phillip , Koehler Lori , Carvalho Marileda
Published: January 2024

Objective

To evaluate the reliability of urine carnitine concentrations measured in single postprandial samples, compared with carnitine concentrations measured in 24-hour urine samples.

Animals

19 healthy Beagles.

Procedure

After emptying the urinary bladder by catheterization, dogs were fed a canned canine maintenance diet. Approximately 8 hours later, urine, plasma, and serum samples were obtained for determination of urinary carnitine fractional excretion and urine carnitine-to-creatinine concentration ratio. Results were compared with 24-hour urinary carnitine excretion rate.

Results

Fractional excretion of carnitine and urine carnitine-to-creatinine ratios correlated poorly with 24-hour urinary carnitine excretion.

Conclusion

Determination of 24-hour urinary carnitine excretion is recommended to measure urine carnitine concentrations in dogs. (Am J Vet Res 1996;57: 1185-1188)
Sensitivity of reproducing sows and suckling pigs to stray voltage
Authors: Robert Suzanne , Matte Jean-Jacques , Martineau Guy Pierre
Published: January 2024

Objective

To evaluate whether stray voltage reduces welfare of sows and their litters, causes reproductive problems, or impairs growth and survival of suckling pigs.

Animals

120 gilts assigned randomly to 3 treatment groups: 2-V baseline plus 3-V pulses (2-5 V); 5-V baseline plus 3-V pulses (5-8 V); and control treatment (0-0 V).

Procedure

Behavior was recorded during gestation and lactation. Water and feed intakes were measured daily, milk composition was evaluated once during lactation, and hematocrit, hemoglobin, glucose, total protein, aspartate transaminase, alanine transaminase, albumin, globulins, and fatty acids values were measured at mating, weeks 8 and 15 of gestation, parturition, and weaning. Prolific ability of sows, mortality and disease of suckling pigs, and growth rate until 56 days of age were recorded.

Results

Gilts under voltage were lying down more often and performing less abnormal behaviors than were control gilts. Behavior of sows and suckling pigs was not affected by treatments. Water and feed intakes were similar among treatments, except during week 1 of lactation where feed intake was lower in the control group. Fecundity and prolific ability of sows, percentage of stillbirth, growth rate of suckling pigs, and milk composition were similar among treatments. More suckling pigs died in 2-5-V group than in other groups, but diarrhea was more frequent in the control group. Blood metabolites were similar among treatment groups.

Conclusions

Transient stray voltage at values up to 8 V did not impair the welfare, reproductive performance, or health of sows and suckling pigs. (Am J Vet Res 1996;57:1245-1249)
Effects of serum separation tubes on serum benzodiazepine and phenobarbital concentrations in clinically normal and epileptic dogs
Authors: Boothe Dawn M. , Simpson Guy , Foster Tammy
Published: January 2024

Objective

To characterize the effects of serum separation tubes (SST) on serum drug concentrations.

Sample Population

Clinically normal dogs (clorazepate, n = 7) or dogs with epilepsy (phenobarbital, n = 7) were studied in experiment 1, and samples submitted for therapeutic drug monitoring (n = 87) were studied in ex-periment 2.

Procedure

In experiment 1, blood containing either drug was placed in 2 types of 4-ml SST (SST-A and SST-B) and in nonserum separation tubes (non-SST [control]). Samples were processed, then stored at 20 to 22 C (both drugs) or 10 C (phenobarbital only). Aliquots were collected for 96 hours. The rate constant of disappearance and the percentage decrease of each drug over time were determined for each tube. For experiment 2, paired samples were collected in non-SST and SST and submitted by mail for therapeutic drug monitoring. The SST samples were either decanted from SST prior to shipment (group 1; n = 30) or mailed in SST with serum in contact with the silica gel (group 2; n = 57). Drug concentrations and drug elimination half-life were compared between groups. For both experiments, drugs were detected in samples, using polarized immunofluorescence.

Results

For experiment 1, the rate constant of drug disappearance for both drugs was greater in the 4-ml SST-A (P <0.0001). This SST also caused the greatest percentage decrease (20% for phenobarbital and 35% for benzodiazepines) at 96 hours. Refrigeration reduced the mean decrease in phenobarbital at 96 hours to 11%. For experiment 2, phenobarbital concentration was lower for both SST, compared with non-SST (P < 0.0005). Phenobarbital had decreased a mean 6.4 ± 0.5% in group-1 and a mean 30.5 ± 11.1% in group-2 (P < 0.0005) samples.

Conclusion

The SST should be avoided when collecting serum for monitoring of either phenobarbital or benzodiazepines.

Clinical Relevance

The SST can falsely decrease serum drug concentrations and should be avoided when collecting blood for therapeutic drug monitoring. (Am J Vet Res 1996;57:1299-1303)
Regulation of activation of bovine neutrophils by aggregated immunoglobulin G
Authors: Leino Lasse , Paape Max J.
Published: January 2024

Objectives

To investigate the role of extracellular Ca2+ and Mg2+ in aggregated IgG (algG)-mediated cellular activation, and to determine how algG-induced activation is coupled to Ca2+ homeostasis in bovine neutrophils.

Sample Population

4 clinically normal, lactating Holstein cows, in their second lactation, which ranged between 60 and 150 days.

Procedure

algG was prepared by heating bovine igG, and C5a was obtained by activating fetal bovine serum with zymosan. Luminol-amplified chemiluminescence (CL) of isolated neutrophils was measured in the presence of algG or phorbol 12-myristate 13-acetate (PMA). The reaction mixture contained either Hanks’ balanced salt solution or Ca2+- and Mg2+-free Hanks’ balanced salt solution. Binding of algG to neutrophils was measured by flow cytometry after incubation with fluorescein isothiocyanate-conjugated second antibody. Intracellular-free concentration [Ca2+] was measured in a fluorescence spectrofluorometer after incubation of neutrophils, loaded with the fluorescent dye fura-2 acetoxymethyl ester, with either algG or C5a.

Results

In a Ca2+- and Mg2+-containing reaction mixture, algG induced strong CL responses, whereas removal of extracellular divalent cations almost abolished the respiratory burst activity. The CL emission on stimulation with PMA was independent of extracellular Ca2+ and Mg2+. Examination of cells by flow cytometry after incubation with algG indicated that the binding of algG was identical in the presence and absence of extracellular Ca2+ and Mg2+. No increase in [Ca2+] was seen in fura-2 acetoxymethylester-loaded neutrophils after stimulation with algG. C5a induced a typical transient increase in [Ca2+].

Conclusions

algG-induced activation of bovine neutrophils is highly dependent on presence of extracellular divalent cations. This dependency is not caused by the need of divalent cations for binding of algG by neutrophils or because the influx of Ca2+ from the extracellular space is an integral component of algG-mediated activation pathway. Because need for extracellular Ca2+ and Mg2+ could be partially circumvented by pretreating neutrophils with PMA, it is possible that this activation pathway may involve a protein kinase C, which is not directly coupled to receptors for algG. (Am J Vet Res 1996;57:1312-1316)
Evaluation of analgesia and cardiorespiratory effects of epidurally administered butorphanol in isoflurane-anesthetized dogs
Authors: Troncy Eric , Cuvelliez Sophie G. , Blais Diane
Published: January 2024

Objective

To determine variations in minimal alveolar concentration (MAC) of isoflurane and analgesic and cardiorespiratory effects of lumbosacral epidural administration of 0.25 mg of butorphanol/kg of body weight in dogs.

Animals

16 healthy male dogs.

Procedure

Dogs were anesthetized with isoflurane alone. Eight dogs received butorphanol (group B) and the others an equal volume of isotonic saline solution (group S) administered by a catheter inserted in the lumbosacral epidural space. Isoflurane MAC was determined before and 30 minutes after the epidural injection, along with noxious stimulation to the fore- and hind limbs. Cardiorespiratory variables were recorded prior to and until 120 minutes after epidural administration. At that time, isoflurane anesthesia was ended, and nociception (toe pinch and pin-prick responses) was evaluated for 7 hours. Dogs were observed for 3 days to determine presence of neurologic side effects.

Results

For group-B dogs, isoflurane MAC decreased by 31 ± 8.6% after butorphanol was administered. Cutaneous insensitivity (to pin-prick nociceptive test) persisted for 3 hours after the end of isoflurane anesthesia in group-B dogs. No response was observed to toe pinch stimulation for 80 minutes after anesthesia.

Conclusions

Epidural administration of 0.25 mg of butorphanol/kg in dogs was safe; minimal cardiorespiratory and no neurologic side effects were observed, and analgesia and an isoflurane-sparing effect were apparent.

Clinical Relevance

The short duration of action of epidurally administered butorphanol limits its value for clinical practice. (Am J Vet Res 1996;57:1478-1482)
Cerebrospinal fluid acid-base status during normocapnia and acute hypercapnia in equine neonates
Authors: Geiser Dennis Richard , Andrews Frank Michael , Rohrbach Barton Wing , Provenza Melanie Kay
Published: January 2024

Objective

To determine normal acid-base status of the CSF and to compare it with changes during acute hypercapnia in equine neonates.

Animals

10 clinically normal foals between 1 and 12 days old.

Procedure

CSF and arterial and venous blood samples were collected every 15 minutes during 45 minutes of normocapnia and 90 minutes of hypercapnia in isoflurane-anesthetized foals. CSF samples were collected via a subarachnoid catheter placed in the atlanto-occipital space.

Results

Comparison of blood and CSF gases during normocapnia indicated that CSF was significantly more acidic than blood. The lower pH was attributable to higher CO2 and lower bicarbonate concentrations than those in blood. During hypercapnia, CSF CO2 increased and pH decreased parallel to changes in blood, but changes were not as great as similar changes in venous blood, indicating that some degree of buffering occurs in the CSF of foals.

Conclusions

Normal CSF acid-base status in equine neonates is similar to that in other domestic species. The blood-brain and blood-CSF interfaces in neonates allow rapid diffusion of CO2, but allow only slow diffusion of bicarbonate. Equine neonates are capable of buffering respiratory-induced acid-base changes in the CSF, but the buffering capacity is less than that of the vascular compartment.

Clinical Relevance

Neonatal foals may develop severe respiratory compromise, resulting in hypoxemia and hypercapnia. Because the ability of the CSF to buffer acid-base changes in neonates is reduced, hypercapnia may contribute to the CNS abnormalities that often develop in sick neonates. Thus, normal blood gas values should be maintained in diseased equine neonates. (Am J Vet Res 1996;57:1483-1487)
Effects of acepromazine maleate and phenoxybenzamine on urethral pressure profiles of anesthetized, healthy, sexually intact male cats
Authors: Marks Steven L. , Straeter-Knowlen Ingrid M. , Moore Michael , Speth Robert , Rishniw Mark , Knowlen Grant G.
Published: January 2024

Objectives

To evaluate the effects of 2 compounds with α-adrenergic antagonist properties on the urethral pressures of anesthetized, healthy, sexually intact male cats, and to evaluate one of the compounds for effect on striated muscle.

Animals

20 healthy, sexually intact male cats.

Procedure

Cats were anesthetized with halothane, and urethral pressure profilometry was performed before and after treatment. 125l-labeled α-bungarotoxin bound to nicotinic receptors of murine skeletal muscle was used in a competitive binding study with acepromazine maleate.

Results

Acepromazine maleate significantly decreased intraurethral pressures in the preprostatic (19%) and pro-static (21%) regions of the urethra. There was no effect on the postprostatic/penile segment. Acepromazine did not inhibit 125l-labeled α-bungarotoxin binding to nicotinic receptors in murine skeletal muscle. Phenoxybenzamine significantly decreased intraurethral pressures (14%) in the preprostatic region of the urethra only.

Conclusions

Acepromazine maleate and phenoxy-benzamine have effects on the smooth muscle of the urethra of healthy, male cats. Acepromazine has no effect on striated muscle.

Clinical Relevance

α-Adrenergic compounds may be used in the pharmacologic management of feline urinary tract disease. (Am J Vet Res 1996;57:1497-1500)
Effects of long-term treatment with enalapril or hydralazine on the renin-angiotensin-aldosterone system and fluid balance in dogs with naturally acquired mitral valve regurgitation
Authors: Haggstrom Jens , Hansson Kerstin , Karlberg Bengt E. , Kvart Clarence , Madej Andrzej , Olsson Kerstin
Published: January 2024

Objective

To study long-term effects of enalapril, an angiotensin-converting enzyme inhibitor, and hydralazine, an arteriodilator, on renin-angiotensin-aldosterone system and fluid balance before and after administration of furosemide.

Animals

22 dogs with clinical signs of congestive heart failure (CHF) attributable to mitral regurgitation.

Procedure

After initial examination, 12 dogs received enalapril and 10 received hydralazine. Dogs were re-examined 3 weeks and 6 months after initial examination. Furosemide was added after the 3-week examination, and at 6 months, dogs had received furosemide for at least 4 months.

Results

Angiotensin II and aldosterone plasma concentrations were low before treatment, and only aldosterone became significantly decreased after enalapril monotherapy. Concentrations of both hormones and heart rate increased in dogs receiving hydralazine monotherapy, and fluid retention was evident. After long-term treatment with either of the 2 drugs together with furosemide, angiotensin II and aldosterone values increased in both groups. Natriuresis and kaliuresis developed in all dogs, with greatest effect in those receiving enalapril and furosemide. These dogs had decreased plasma sodium concentration, whereas potassium concentration was equally decreased in both groups. After 6 months, the enalapril group, but not the hydralazine group, had increased cardiac size. All dogs had moderate reduction of weight and were azotemic, although changes were more pronounced in those of the hydralazine group.

Conclusion

The 2 drugs have different effects on the renin-angiotensin-aldosterone system and fluid balance in dogs with CHF. (Am J Vet Res 1996;57:1645–1652)
Endotoxin stimulates in vitro pituitary growth hormone release in eicosanoid-dependent manner
Authors: Coleman E. S. , Sartin J. L.
Published: January 2024

Objective

To investigate the signal transduction pathways by which endotoxin stimulates in vitro pituitary cell growth hormone (GH) release.

Animals

Pituitary cell cultures derived from 6 sheep.

Procedure

Signal transduction pathways involved in endotoxin-mediated GH release from sheep pituitary cell cultures were evaluated by the use of specific blockers of arachidonic acid and its metabolites, extracellular calcium, protein kinase C, and protein kinase A. Cell cultures were exposed to the specific blockers in the presence or absence of endotoxin (Escherichia coli O55:B5, 10 μg/ml) for 24 hours. In addition, effects of endotoxin on GH cell content and GH mRNA values were determined.

Results

Nordihydroquairetic acid (lipoxygenase blocker, 10 μM, 30 μM) and eicosatetraynoic acid (arachidonic acid competitor, 10 μM) decreased endotoxin-stimulated GH release. The calcium channel blocker verapamil (25 μM) decreased baseline and endotoxin-stimulated GH release. Phorbol myristate acetate-induced down-regulation of protein kinase C, indomethacin, or the protein kinase A blocker H89 did not alter endotoxin-stimulated GH release. Endotoxin increased GH mRNA values by 50.1 ± 6.0%, but the cell content of GH was not affected.

Conclusions

A direct effect of endotoxin on the pituitary gland to stimulate GH secretion was evident, an effect mediated predominantly by arachidonic acid and its metabolites through the lipoxygenase pathway. Endotoxin-stimulated GH release requires extracellular calcium and is associated with increased cell GH mRNA content.

Clinical Relevance

A better understanding of the signal transduction pathways involved in endotoxin-mediated effects will allow more appropriate therapeutic intervention in clinical cases of endotoxemia. (Am J Vet Res 1996;57:1662–1667)
Antibody responses measured by various serologic tests in pigs orally inoculated with low numbers of Toxoplasma gondii oocysts
Authors: Dubey J. P. , Andrews C. D. , Lind P. , Kwok O. C. H. , Thulliez P. , Lunney J. K.
Published: January 2024

Objective

To follow antibody responses measured by various serologic tests in pigs orally inoculated with low (≤ 10 oocysts) numbers of Toxoplasma gondii oocysts.

Animals

24, 2- to 3-month-old pigs.

Procedure

Pigs (n = 42) were inoculated orally with 10 (14 pigs) or 1 (28 pigs) infective oocysts, and 6 pigs served as uninoculated controls. Blood (serum) samples were obtained at 1- to 3-week intervals until euthanasia. At necropsy, the brain, heart, and tongue of pigs were bioassayed in mice and cats for isolation of T gondii. Modified agglutination test (MAT), using whole, fixed tachyzoites and mercaptoethanol; latex agglutination test (LAT); indirect hemagglutination test (IHAT); Sabin-Feldman dye test (DT); and ELISA were used to evaluate serologic responses to T gondii.

Results

T gondii was isolated from tissues of 13 of 14 pigs each fed 10 oocysts, 17 of 28 pigs each fed 1 oocyst, and 0 of 6 control pigs. 29 of 30 T gondii-infected pigs developed antibodies when measured by MAT, DT, and ELISA; the 1 seronegative-infected pig had been fed 10 oocysts and was euthanatized 69 days after inoculation. LAT detected antibodies in 26 of 30 T gondii-infected pigs. IHAT detected antibodies in 11 T gondii-infected pigs.

Conclusion

MAT, DT, and ELISA were more sensitive serologic assays than LAT and IHAT for detecting antibodies induced by low numbers of T gondii in pigs. (Am J Vet Res 1996;57:1733–1737)
Effects of selenium and vitamin E administration during a late stage of pregnancy on colostrum and milk production in dairy cows, and on passive immunity and growth of their offspring
Authors: Lacetera Nicola , Bemabucci Umberto , Ronchi Bruno , Nardone Alessandro
Published: January 2024

Objective

To determine effects of selenium (Se) and vitamin E (VE) administration in late pregnancy on Se status, plasma immunoglobulin concentrations, and colostrum and milk production of dairy cows, and on Se status, passive immunity, and growth of their offspring.

Animals

25 Holstein cows and their offspring.

Procedure

3 and 1.5 weeks before calving, sodium selenite (5 mg/100 kg of body weight) and d, l-α-tocopheryl acetate (25 IU/100 kg) were administered to 13 cows. The other 12 cows were not treated. Se status was assessed by measurement of glutathione peroxidase activity of erythrocytes (GSH-Px-E).

Results

The 13 treated cows had higher (P < 0.01) GSH-Px-E values at calving and during the first 12 weeks of lactation. Changes in plasma immunoglobulin concentrations before or after calving did not differ between the 2 groups of cows. During the first 36 hours after calving (4 milkings), treated cows produced 22% more colostrum than did their nontreated counterparts (P < 0.005). Percentages of colostral immunoglobulins did not differ between the 2 groups. During the first 12 weeks of lactation, treated cows produced 10% more milk than did nontreated cows (P < 0.005). GSH-Px-E values at birth and 28 days of life were significantly higher in calves from treated cows. Plasma immunoglobulin concentrations and body weight during the first 56 days after birth did not differ between calves born to treated or non-treated cows.

Conclusions and Clinical Relevance

Cows given Se and VE in late pregnancy produce large quantities of colostrum and milk. Colostrum produced from cows given Se and VE is suitable to feed newborn calves and to be stored for later use. Improvement of Se status in calves born to cows given Se and VE in late pregnancy is not beneficial to passive immunity and growth. (Am J Vet Res 1996;57:1776–1780)
Isolation and characterization of the canine melanoma antigen recognized by the murine monoclonal antibody IBF9 and its distribution in cultured canine melanoma cell lines
Authors: Oliver J. L. , Wolfe L. G. , Lopez M. K. , Church-Bird A. , Toivio-Kinnucan M. , Dietrich M. A.
Published: January 2024

Objective

To characterize the canine melanoma antigen recognized by the murine monoclonal antibody IBF9 as to its cellular location, molecular size, protein and glycogen contents, and distribution in cell lines.

Sample Population

7 cultured canine melanoma cell lines.

Procedure

Molecular characteristics of the antigen were determined by western blotting, enzymatic digestion studies, and tunicamycin inhibition studies. Distribution of the antigen in the cultured melanoma cell lines was determined by flow cytometry.

Results

The antigen consists of 2 proteins with molecular mass of 89 and 85 kd. Tunicamycin and enzymatic digestion studies indicated that these proteins contained little glycosylation. Immunogold and immunofluorescence studies localized the antigen to the cell surface. Antigen expression was consistent within each cell line, with > 90% of the cells positive for all cell lines except 1 (80%). Percentage of positive cells and relative intensity of immunostaining were constant throughout all phases of the cell cycle.

Conclusions

The antigen identified by MAB IBF9 is a well-conserved and highly expressed cell surface protein present during all phases of the cell cycle in all malignant canine melanoma cell lines examined.

Clinical Relevance

Because of consistency in expression, the antigen may have potential for use in dogs for melanoma immunodiagnostics and immunotherapy. (Am J Vet Res 1997;58:46–52)
Characterization of anatomic communications among the antebrachiocarpal, middle carpal, and carpometacarpal joints in cattle, using intra-articular latex, positive-contrast arthrography, and fluoroscopy
Authors: Desrochers André , St.-Jean Guy , Cash Walter C. , Hoskinson James J. , DeBowes Richard M.
Published: January 2024

Objective

To evaluate the frequency and sites of communication among the antebrachiocarpal, middle carpal, and carpometacarpal joints in cattle.

Animals

137 limbs were obtained from 72 fresh bovine cadavers submitted for necropsy because of problems unrelated to the carpus.

Procedure

1 of the 3 injection sites was randomly assigned to both carpi of each ox, and a mixture of latex and barium sulfate was injected into the joint. Communication between 2 or more joints was determined by the presence of latex and contrast material in a joint adjacent to the injected joint by examination of frozen sections, positive-contrast arthrography, and fluoroscopy.

Results

Communication existed among the 3 joints in 18 specimens (13.1%). The middle carpal joint and the carpometacarpal joint always communicated. The antebrachiocarpal joint communicated with the middle carpal joint between the ulnar and intermediate carpal bones. The middle carpal and carpometacarpal joints always communicated between the fourth and fused second and third carpal bones. In a few specimens, additional sites of communication were identified at the palmar aspect of the fourth carpal bone and the fused second and third carpal bones.

Conclusions and Clinical Relevance

Individual anatomic variation of the carpus in cattle should be considered when diagnostic or treatment protocols are established. (Am J Vet Res 1997;58:7–10)
Biochemical, histochemical, and immunohistochemical characterization of distal tibial osteochondrosis in horses
Authors: Lillich J. D. , Bertone Alicia L. , Malemud Charles J. , Weisbrode Steven E. , Ruggles Alan J. , Stevenson Sharon
Published: January 2024

Objective

To compare the biochemical, histochemical, and immunohistochemical profiles of articular cartilage from horses with naturally acquired distal tibial osteochondrosis (OC) with cartilage from a similar location in clinically normal horses.

Animals

9 affected horses (group 1, 16 OC lesions) and 4 control horses (group 2, 8 normal osteochondral specimens).

Procedure

OC specimens were collected during arthroscopic removal of the fragment, and control specimens were collected by aseptic osteotomy. Uronic acid, total protein, total glycosaminoglycan (GAG), chondroitin sulfate (CS), and keratan sulfate (KS) contents were determined. Histomorphologic, histochemical, and immunohistochemical examinations were performed on specimens after snap freezing at −80 C and cryosectioning. Monoclonal antibodies (MAB) 3B3 and 5D4 were applied for location of epitopes of CS and KS, respectively.

Results

OC lesions had significantly lower quantity of uronic acid, total GAG, and CS, compared with normal cartilage. OC cartilage had significantly less intense staining with toluidine blue, along with irregular cellularity and tidemark characteristics, compared with normal cartilage. Monoclonal antibodies 3B3 and 5D4 stained OC cartilage, whereas MAB 5D4 did not stain control cartilage. Additionally, MAB 3B3 and 5D4 stained the fibrous tissue that was found firmly attached to the OC lesion located between the parent distal portion of the tibia and OC fragment.

Conclusion

OC cartilage lesions of the distal intermediate ridge of the tibia in horses are biochemically, histochemically, and immunohistochemically distinct from normal cartilage from the same location. Results may reflect the inability of the chondrocyte of the developing joint to alter matrix components that would allow proper maturation and differentiation into bone. (Am J Vet Res 1997;58:89–98)
Spectro-temporal mapping of the surface electrocardiogram in clinically normal dogs
Authors: Calvert Clay A. , Kushner Lynn I. , Jacobs Gilbert J. , Brown John
Published: January 2024

Objectives

To establish data for selected variables of the signal-averaged ECG and determine whether sedation affects segment lengths and points within the terminal QRS complex where windows began.

Sample Population

Overtly healthy dogs with no detected abnormalities.

Procedure

Signal-averaged ECG (600 beats) were obtained from dogs in left-lateral recumbency, using X, Y, and Z leads with 26-gauge subdermal platinum electrodes. Frequency-domain analyses were performed by fast Fourier transform (FFT), using a postprocessing computer software package. Analyses were extracted from 30-, 40-, and 50-millisecond windowed (Blackman-Harris) segments of the terminal 10 or 20 milliseconds of the QRS complex and ST segment. Correlation ratios were calculated by cross-correlation of frequency spectra of each FFT in the range of 40 to 200 Hz. The reference spectrum was the last FFT (nearest the T wave). Spectro-temporal maps were plotted for each analysis.

Results

Noise levels were < 1 μV. Sedation resulted in less noise and slower heart rate, but did not affect results. Correlation ratios were not different among 30-, 40-, and 50-millisecond segments, but were lower when 20 (vs 10) milliseconds of the terminal QRS was included. Spectro-temporal maps were similar in all subjects.

Conclusions

Use of sedation facilitated the procedure without affecting results. Segment lengths of 40 and 50 milliseconds, beginning 10 milliseconds prior to the end of the QRS complex and analyzed in the range of 40 to 200 Hz, yielded correlation ratios > 67%, 95% of the time.

Clinical Relevance

Spectro-temporal mapping may identify dogs with ventricular late potentials (high-frequency signals commonly associated with myocardial fibrosis) that may be at increased risk of sudden death. (Am J Vet Res 1997;58:211–217)
Determination of an effective dose of eltenac and its comparison with that of flunixin meglumine in horses after experimentally induced carpitis
Authors: Hamm D. , Turchi P. , Johnson J. C. , Lockwood P. W. , Thompson K. C. , Katz T.
Published: January 2024

Objectives

To titrate a clinically effective eltenac dosage (0.1, 0.5, and 1.0 mg/kg of body weight), compared with vehicle only, and to compare efficacy of the most effective eltenac dosage with that of 1.1 mg of flunixin meglumine/kg.

Animals

40 healthy horses, ranked after model induction on the basis of lameness severity, were randomly assigned to 5 treatment groups, with 4 replicates of 10 horses each.

Procedure

On day -5, after surgical preparation of the left carpal region, 0.7 ml of Freund's complete adjuvant was injected into the intercarpal space. Horses were observed daily, from the day of carpitis induction to day 0, when stride length was used as the method of ranking horses for randomization to treatment assignment. Treatments were administered IV once daily for 3 consecutive days, starting on day 0. Prior to carpitis induction on day -5, and at time 0 (pretreatment). 2, 4, 12, 24, 36. 48, 60, 72, and 96 hours after treatment initiation, resting respiratory rate and pulse, rectal temperature, carpal circumference, carpal flexion angle, stride length, carpal hyperthermia, and signs of carpal pain were recorded.

Results

Compared with the vehicle and 0.1 mg of eltenac/kg, 0.5 and 1.0 mg/kg caused statistically significant improvements (ie, reduction of carpal circumference, increase in carpal flexion angle, and increase in stride length of the affected limb), but values did not differ significantly between the 2 dosages. Thus, a dose-response plateau for eltenac was reached at 0.5 mg/kg.

Comparison with flunixin meglumine at a dosage of 1.1 mg/kg did not indicate significant differences between the 2 treatment groups at the pivotal time of 96 hours for carpal circumference, carpal flexion angle, stride length, carpal hyperthermia, and signs of carpal pain. Adverse reactions were not observed.

Clinical Relevance

Under conditions of this study, a dosage plateau for eltenac was determined (0.5 mg/kg) that was statistically equivalent to eltenac (1.0 mg/kg) and flunixin meglumine (1.1 mg/kg) in a 3-day IV dosing regimen. (Am J Vet Res 1997;58:298–302)
Ventilatory effects of the single-breath CO2 test, compared with eructation, in cattle
Authors: Rollin F. , Desmecht D. , Genicot B. , Linden A. , Lomba F. , Lekeux P.
Published: January 2024

Objective

To assess the peripheral chemoreceptor-induced ventilatory response to single tidal-breath CO2 (SB CO2) tests, compared with eructations, in 2 breeds of calves.

Animals

13 conscious unsedated Holstein-Friesian and 8 Belgian White and Blue hypermuscled calves.

Procedure

An SB of ± 50% CO2 in equal parts of O2 and N2 was inhaled. Ventilatory response was determined from the increase in ventilation (ΔVe) during the first 20 seconds after the test breath or eructation and from the difference in end-tidal PCO2 between the stimulus and preceding control breaths.

Results

Because no difference was found between the 2 breeds of calves, all data were pooled. The increase in Ve peaked during the fifth breath after the SB CO2 test on average, corresponding to a delay of 12.4 seconds. The SB CO2 responses ranged from 0.037 to 0.151 L/min·mm of Hg·m2, with a mean ± SD of 0.082 ± 0.032 L/min·mm of Hg·m2 for all calves. The SB CO2 tests, similar to eructations, modified the breathing pattern significantly and in the same direction, by principally shortening expiratory time and increasing mean inspiratory flow. After eructations, Ve peak increase was more important for lower difference in end-tidal PCO2 between the stimulus and preceding control breaths and took place more rapidly than after SB CO2 tests. Accordingly, eructation responses were more marked than SB CO2 responses and averaged 0.925 ± 0.276 L/min·mm of Hg·m2.

Conclusions and Clinical Relevance

In cattle, the pattern of breathing and ventilation under basal conditions is characterized by a cyclic variability coupled to eructation. (Am J Vet Res 1997;58:310–316)
Structural, material, and anatomic characteristics of the collateral ligaments of the canine cubital joint
Authors: Vogelsang Robert L. , Vasseur Philip B. , Peauroi John R. , Kass Phil H. , Sharkey Neil
Published: January 2024

Objective

To document gross and microscopic anatomic features of the collateral ligaments of the canine cubital joint and to determine their structural and material properties.

Animals

37 canine cadavers.

Procedure

After measurement of ligament dimensions, the bone-collateral ligament-bone specimens were loaded in tension until failure, using a materials testing machine. Data from the load-displacement curves were used to determine the structural and material properties of the ligaments. Gross anatomic features were studied during dissection of the specimens from the medial collateral ligament (MCL) and lateral collateral ligament (LCL), which then were saved for microscopic examination.

Results

Failure load and stiffness values for the LCL were significantly (P < 0.05) greater than those for the MCL. The LCL had obvious cranial and caudal components that attached to the radius and ulna, respectively. The MCL also had cranial and caudal components; however, the cranial component was indistinct, appearing only as a slight thickening of the joint capsule. The caudal component was more prominent; as it extended distad, it had minor attachments to the interosseous and annular ligaments and attached principally on the caudolateral surface of the proximal portion of the radius. The caudal component did not have substantial attachment to the ulna in any of the specimens studied. Both ligaments were composed of closely packed, parallel fascicles of dense collagen, with scant amounts of fibrocartilage and no detectable elastin.

Conclusions

Gross anatomic features of the collateral ligaments of the canine cubital joint indicate that they provide principal structural support to the joint; microscopic anatomic features are typical of other ligaments. The LCL is stronger and stiffer than the MCL; however, their material properties are similar.

Clinical Relevance

Knowledge of the sites of attachment of collateral ligament components is essential for surgeons undertaking repair or reconstruction of these structures. (Am J Vet Res 1997;58:461–466)
Effect of heparin on infection of cells by porcine reproductive and respiratory syndrome virus
Authors: Jusa Enuh R. , Inaba Yuji , Kouno Michihiro , Hirose Osamu
Published: January 2024

Objective

To investigate whether heparin has any effect on the growth of porcine reproductive and respiratory syndrome virus (PRRSV).

Sample Population

2 isolates of PRRSV, and as control viruses, 1 isolate of pseudorabies virus (PRV) and 1 isolate of parainfluenza 3 virus (PIV-3).

Procedures

Plaque assays, using a continuous cell line (MARC-145) derived from African green monkey kidney cell line (MA104), were performed for determination of inhibitory effect of heparin on PRRSV, PRV, and PIV-3. The effect of various doses of heparin and heparinase on the growth of PRRSV, PRV, and PIV-3 was evaluated and compared. In each experiment, values were expressed as the mean value for duplicate samples.

Results

The number of plaques formed by PRRSV and PRV was reduced to 24 to 25 and 15% of the untreated control (100%), respectively, by 1 U of heparin/ml, but could not be reduced below 6 to 7 and 3%, respectively, by use of concentrations up to 50 U/ml. An inhibitory effect of heparin, at a concentration up to 50 U/ml, was not observed on PIV-3. Delaying addition of heparin for 30 minutes after the addition of PRRSV and PRV reduced plaque formation by 48 to 51 and 68%, respectively, compared with 91 to 92 and 95%, respectively, if heparin was added at the time of infection. In addition, most PRRSV added was retained by heparin beads, as was PRV. Heparinase treatment of MARC-145 cells reduced the number of PRRSV-, as well as PRV-induced plaques. On the other hand, the number of PIV-3-induced plaques did not decrease after treatment of MARC-145 cells with heparinase.

Conclusions

Addition of heparin to PRRSV or to the MARC-145 cells before virus inoculation and treatment of the cells with heparinase prevented the virus from infecting the cells. (Am J Vet Res 1997;58:488–491)
Protective vaccination of ferrets against canine distemper with recombinant pox virus vaccines expressing the H or F genes of rinderpest virus
Authors: Jones Leslie , Tenorio Edgar , Gorham John , Yilma Tilahun
Published: January 2024

Objective

To investigate the ability of rinderpest virus (RPV) antigens, expressed in pox virus vectors, to protect against canine distemper virus (CDV) infection in ferrets.

Animals

Ferrets (Mustela putorius; n = 27) with no previous exposure to CDV.

Procedure

Ferrets were inoculated intradermally with recombinant vaccinia viruses expressing the H gene of RPV, the F gene of RPV, the H and F genes of RPV, or a fowlpox virus recombinant expressing both genes. Two ferrets were vaccinated SC with CDV vaccine as positive controls, and 1 group was left unvaccinated as a negative control. Blood was obtained from ferrets biweekly; antibody titer to RPV was detected by ELISA, and CDV antibody titer was measured by serum neutralization testing and ELISA.

Results

Partial protection was seen in all groups, with vRVFH vaccination being the most protective (60%).

Conclusions and Clinical Relevance

A single inoculation with a vaccinia virus expressing the H and F genes of RPV was able to protect 60% of the vaccinated ferrets challenge exposed with a high dose of CDV. These results indicate the ability of RPV antigens expressed by vaccinia virus to protect ferrets against a related morbillivirus. Further, they document the safety and efficacy of a recombinant vaccinia virus vaccine for ferrets. Such vaccines may be useful given the susceptibility of ferrets to CDV and the problem of maternal antibody interfering with vaccination of young animals. (Am J Vet Res 1997;58:590–593)
Evaluation of an animal rabies vaccine by use of two types of potency tests
Authors: Baer George M.
Published: January 2024

Objective

To evaluate the potency of an inactivated animal rabies vaccine for domestic animals by use of 2 types of potency tests after challenge exposure with a laboratory standard virus or 1 of 5 viruses obtained from various wildlife species.

Animals

384 mice vaccinated twice intraperitoneally; 384 mice vaccinated once IM.

Procedure

Mice vaccinated with an inactivated, adjuvanted rabies vaccine for domestic animals were challenge exposed with the common fixed challenge virus or 1 of 5 rabies viruses obtained from wild animal species (street viruses) that most commonly transmit the virus in the United States and Canada. Potency tests included 2 types of antigen extinction tests: the National Institutes of Health (NIH) test and the Centers for Disease Control test.

Results

Results of both tests indicated that protection was highest against raccoon and bat viruses. Marked differences were detected in the relative potency ratios for the NIH versus the Centers for Disease Control tests, though the relative potencies themselves (against the street viruses) did not differ markedly.

Conclusions

The markedly reduced potency against the street viruses indicated by the NIH test results was suggestive of an inherent bias associated with double intraperitoneal vaccination and intracerebral challenge exposure, whereas the single IM vaccination and IM challenge exposure reduced that bias. (Am J Vet Res 1997;58:837–840)
Efficacy of imidacloprid for removal and control of fleas (Ctenocephalides felis) on dogs
Authors: Arther Robert G. , Cunningham Jerry , Dorn Hubert , Everett Ronald , Herr Leslie G. , Hopkins Terence
Published: January 2024

Objective

To evaluate efficacy of a 9.1% (w/w) imidacloprid solution, applied topically, to remove fleas from dogs and the duration of residual flea control when dogs were exposed to continuing flea infestation.

Animals

32 adult mixed-breed dogs.

Procedure

Dogs were allocated to 4 groups of 8 dogs each; dogs of 3 groups received a single dose of imidacloprid, and those of the fourth group received excipient. Each dog was infested with 100 adult fleas on study days -3, -1, 6, 13, 20, 27, and 33. Treatments were applied on day 0. Each dog was examined for live fleas on days -2, 1, 7, 14, 21, 28, and 34. Posttreatment efficacy was determined by comparing the mean number of live fleas remaining on the treated dogs with the mean number of live fleas remaining on the control dogs.

Results

All 3 imidacloprid dosages provided flea control ≥ 96.9% one day after treatment. Maximal efficacy of all 3 dosages (99.1 to 100%) was observed at 7 days after treatment. Flea control with 3.75 mg of imidacloprid/kg of body weight ranged from 94.4 to 96.9% for days 14 to 28 and decreased to 91.6% by 34 days after treatment. Flea control with 7.5 and 10.0 mg of imidacloprid/kg was 97.8 to 100% through day 28. At day 34, dosages of 7.5 and 10.0 mg of imidacloprid/kg were 97.6 and 96.9% efficacious, respectively.

Conclusion

7.5 or 10.0 mg of imidacloprid/kg are equivalent and superior to 3.75 mg/kg for flea control over the course of a 34 day posttreatment period.

Clinical Relevance

Monthly imidacloprid application of 7.5 to 10 mg/kg will rapidly kill existing and reinfesting flea infestations on dogs and break the flea life cycle by killing adult fleas before egg production begins. (Am J Vet Res 1997;58:848–850)
Comparison of effects of albendazole sulfoxide on in vitro produced bovine embryos and rat embryos
Authors: Piscopo Susan E. , Smoak Ida W.
Published: January 2024

Objective

To evaluate and compare effects of albendazole sulfoxide (ABZSO) on rat embryos and bovine embryos produced in vitro.

Animals

In vitro produced bovine embryos. Rat embryos recovered from naturally bred Sprague-Dawley rats.

Procedure

4- and 8-cell bovine embryos were randomly allocated to ABZSO or vehicle control groups. After 48 hours, embryos were evaluated for cell number and blastomere morphology. Rat embryos of similar stages, flushed from the uterine tube on gestational day 2.5, were randomly allocated to treatment or control groups. After 24 hours, embryos were evaluated as described previously.

Results

44% of control bovine embryos divided in culture (≥ 16-cell stage). Fifteen percent of the controls had morphologic abnormalities, including disparity in blastomere size and cytoplasmic vacuoles and stippling. Treated (≥ 1 μg of ABZSO/ml) bovine embryos differed (P < 0.0001) from controls, with 4% development and 93% abnormal morphology. Forty-five percent of control rat embryos divided in culture. Treated (≥ 500 ng of ABZSO/ml) rat embryos differed (P < 0.0003) from controls with regard to ability to divide. There were no consistent morphologic abnormalities in rat embryos.

Conclusions

In vitro produced bovine embryos were susceptible to ABZSO at a concentration ≥ 1 μg/ml, resulting in decreased ability to divide and presence of gross morphologic abnormalities. Rat embryos produced in vivo and exposed in vitro to ABZSO at a concentration > 500 ng/ml had decreased ability to divide in culture.

Clinical Relevance

Despite severe effects of ABZSO (≥ 1 μg/ml) on bovine embryo development in vitro, it is beyond the scope of this study to speculate whether a therapeutic dosage of albendazole (10 mg/kg of body weight) would result in necessary concentrations of ABZSO in vivo to disrupt embryogenesis. (Am J Vet Res 1997;58:1038–1042)