bluuebunny/crossref_metadata_2025 huggingface dataset:
Pulmonary function measurements during repeated environmental challenge of horses with recurrent airway obstruction (heaves)
Authors: Tesarowski David B. , Viel Laurent , McDonell Wayne N.
Published: January 2024

Objectives

To evaluate the degree of reproducibility in clinical variables, blood gas measurements, and lung function variables, and the changes in these variables caused by exposure to moldy hay in naturally sensitized and control horses.

Procedure

The magnitude of variation in arterial blood gas and pulmonary function measurements were evaluated in a model of naturally acquired heaves. Horses with heaves and similarly aged control horses were studied prior to moldy hay challenge and again after the horses with heaves manifested clinical signs of airway obstruction. This cycle of testing was repeated 3 times to determine the variation of the before and after challenge measurements. Variables evaluated for repeatability included: clinical score; arterial O2 and CO2 tensions; pulmonary function variables, such as breathing rate (f), tidal volumes, and flow rates; lung resistance (Rl); dynamic compliance; and work of breathing (Wb).

Results

Before challenge, significant differences observed between control horses and horses with heaves included clinical score, expiratory flow rate at near-end expiration, Rl, and Wb. After exposure to moldy hay, variables measured in control horses were largely unchanged. However, in the afflicted horses, significant changes were observed for clinical score, arterial O2 and CO2 tensions, breathing rate, peak tidal inspiratory and expiratory flow rates, dynamic compliance, Rl, and Wb, compared with prechallenge values and with control horses' postchallenge values. Analysis of the data revealed few statistically significant differences between repeats of challenges.

Conclusion

Horses afflicted with heaves manifest airway obstruction that can be measured in repeatable fashion. (Am J Vet Res 1996;57:1214-1219)
In vitro and in vivo effects of activated macrophage supernatant on distal limb wounds of ponies
Authors: Wilson D. A. , Adelstein E. H. , Keegan K. G. , Barrett B. A. , Kutz R. R.
Published: January 2024

Objective

To determine whether monokines produced by activated rabbit peritoneal macrophages can inhibit development of exuberant granulation tissue formation in distal limb wounds in ponies.

Design

Randomized block.

Animals

5 castrated male ponies, 2 to 6 years old and weighing 140 to 190 kg.

Procedure

In vitro activity of cell-free rabbit peritoneal macrophage supernatant was determined after incubation of fibroblasts from the flank and the distal portion of limbs of horses and ponies. Tritiated thymidine was then added, and after reincubation, radioactivity was measured.

After creation of a 4-cm2, full-thickness wound on the mid dorsal aspect of each metacarpus and metatarsus of each pony, in vivo activity of the macrophage supernatant was evaluated. Biopsy specimens were collected at random sites near a border of each wound at 4, 6, and 10 weeks after creation of the wounds. Treatment effects were evaluated on the basis of presence of exuberant granulation tissue requiring excision, number of times that excision was required, total area of the wound, epithelialized area, area of granulation bed, and histologic evaluation of the biopsy specimens.

Results

The macrophage supernatant effectively inhibited proliferation of equine fibroblasts in vitro. No significant in vivo treatment effects were found among the 4 treatment groups.

Conclusion and Clinical Relevance

Monokines from stimulated rabbit peritoneal macrophages may have potential for improving wound healing in horses and ponies because of their effective inhibition in vitro of equine fibroblast proliferation. (Am J Vet Res 1996;57:1220-1224)
Effect of progesterone on prostaglandin F2α secretion and outcome of pregnancy during cloprostenol-induced abortion in mares
Authors: Daels Peter F. , Besognet Bruno , Hansen Betty , Mohammed Hussni , Odensvik Kristina , Kindahl Hans
Published: January 2024

Objectives

To determine the role of progesterone in the regulation of endogenous prostaglandin F2α (PGF2α) secretion during cloprostenol-induced abortion and to investigate use of progestins to prevent prostaglandin-associated abortion.

Animals

16 pregnant mares.

Procedure

To induce abortion, cloprostenol (250 μg/d) was administered daily until fetal expulsion or for up to 5 days. In experiment 1, 8 mares, 98 to 153 days’ pregnant, received progesterone (300 mg/d) at 24-hour intervals for 5 days, starting 18 hours after the first cloprostenol administration. In experiment 2, 8 mares, 93 to 115 days’ pregnant, received altrenogest (44 mg/d) at 24-hour intervals, starting 12 hours after the first cloprostenol administration. Historic control mares, 82 to 102 days’ pregnant, received cloprostenol (250 μg/d) daily until fetal expulsion.

Results

In control mares, fetal expulsion occurred after 2 to 3 cloprostenol administrations and was associated with significant increases in PGF2α secretion. Abortion did not occur in 5 of 8 progesterone-treated mares and 8 of 8 altrenogest-treated mares, and endogenous PGF2α secretion was inhibited, compared with values in aborting mares.

Conclusion

Circulating progestogen concentrations may have a role in the outcome of pregnancy during prostaglandin-induced abortion. Altered prostaglandin secretion may be a reflection of a direct effect of progesterone or may be caused by the abortion process.

Clinical Relevance

Progestogens might be useful for prevention of abortion in mares in which pregnancy is at risk owing to diseases that are associated with excess prostaglandin secretion. (Am J Vet Res 1996;57:1331-1337)
Quantification of phenylbutazone in equine sera by use of high-performance liquid chromatography with a nonevaporative extraction technique
Authors: Peck K. E. , Ray A. C. , Manuel G. , Rao M. M. , Foos J.
Published: January 2024

Objective

To develop a sensitive, rugged high-performance liquid chromatography (HPLC) method for the measurement of phenylbutazone (PBZ) in equine sera, using a rapid, nonevaporative extraction technique.

Sample Population

Sera from 5 nonexercising adult horses.

Procedure

After addition of sodium chloride and acetonitrile to serum samples, reverse-phase HPLC analysis for PBZ and oxyphenbutazone (OXY) was performed directly on extracts, using diode array UV spectrophotometric detection. Probenecid was used as an internal standard. Data were evaluated by standard means of statistical analysis.

Results

Recoveries of PBZ, OXY, and probenecid from spiked samples were acceptable (ie, ≥ 80%) and within-run retention times were reproducible. Chromatograms were free of interfering substances, and linearity of calibration curves was observed throughout operational ranges. Coefficients of variation at each fortified PBZ concentration were in the 5 to 10% range. The method was applicable to analysis of PBZ and OXY in serum extracts from horses dosed with PBZ (4.4 mg/kg of body weight, IV) in a controlled environment. Track samples analyzed by use of this method and a conventional liquid/liquid extraction method gave comparable results (mean deviation, 1.6%) for PBZ concentrations.

Conclusion

The HPLC protocol described is suitable for measuring PBZ and OXY in equine sera to regulate PBZ administration in horses involved in parimutuel racing. (Am J Vet Res 1996;57:1522–1524)
Effect of bethanechol or erythromycin on gastric emptying in horses
Authors: Ringger N. C. , Lester G. D. , Neuwirth L. , Merritt A. M. , Vetro T. , Harrison J.
Published: January 2024

Objective

To investigate the prokinetic effect of bethanechol and erythromycin in the upper gastrointestinal tract of healthy horses by measuring the gastric emptying (GE) rate of a radioactive meal.

Animals

4 healthy adult horses.

Procedure

After food was withheld for 12 hours, horses were given 370 MBq of 99mTc-labeled sulfur colloid incorporated into egg albumen and 37 MBq of 111In-labeled diethyltriaminepentaacetic acid in 120 ml of water via nasogastric intubation. Intravenously administered treatments were 0.9% NaCl solution, erythromycin (0.1 or 1.0 mg/kg of body weight), or bethanechol (0.25 mg/kg). All drugs were given in 10 ml of 0.9% NaCl solution. Dualphase scintigraphic images were obtained by use of a gamma camera. The best-fit function was determined for each study, and the resultant curves were then analyzed by use of least squares nonlinear regression. Two variables, time to 50% emptying of the stomach (T-50) and slope of the emptying curve, were derived from the calculated power exponential equation.

Conclusions

Treatment had a significant (P < 0.05) overall effect on T-50 of solid-phase GE. The T-50 of bethanechol (30.09 ± 10.01 minutes), erythromycin at 0.1 mg/kg (59.08 ± 10.01 minutes), and erythromycin at 1 mg/kg (60.50 ± 10.01 minutes) were significantly shorter than T-50 after saline administration (89.97 ± 10.01 minutes). There was a trend (P = 0.09) for the slope of solid-phase GE of bethanechol and erythromycin (0.1 mg/kg; P = 0.37) to be steeper than that of saline solution. For liquid-phase GE, the T-50 and the slope of bethanechol differed significantly (P < 0.05) from those for saline solution.

Clinical Relevance

Bethanechol and erythromycin significantly increased solid-phase GE in healthy horses and may have value for use as prokinetic agents in certain gastrointestinal tract diseases. (Am J Vet Res 1996;57:1771–1775)
Effect of treatment with erythromycin on bronchoalveolar lavage fluid cell populations in foals
Authors: Lakritz Jeffrey , Wilson W. David , Watson Johanna L. , Hyde Dallas M. , Mihalyi Judy , Plopper Charles G.
Published: January 2024

Objective

To determine whether oral administration of erythromycin alters the inflammatory response to bronchoalveolar lavage (BAL) in young horses.

Animals

12 healthy, unweaned, mixed-breed foals of either sex, between 2 and 4 months old.

Procedure

BAL was performed; 250 ml of phosphate-buffered saline solution (300 mOsm, pH 7.4) was administered in 50-ml aliquots. Foals were carefully monitored for 4 days, then erythromycin base (25 mg/kg of body weight, PO, q 12 h) was given to foals of the treated group. After 4 days, foals were re-anesthetized, and the same lung was relavaged. Cytologic examination was performed on BAL fluid (BALF) samples from both groups of foals. At 12 hours after administration of the final dose, erythromycin A and anhydroerythromycin A concentrations were determined in plasma of treated foals.

Results

In the second BALF sample from the same lung of control foals, percentage of neutrophils was significantly increased (3 ± 38.0%), compared with that from erythromycin-treated foals (4.88 ± 3.66%, P < 0.05), and was associated with apparent decrease in the ability of BALF cells from erythromycin-treated foals to migrate toward a chemoattractant source. Significantly fewer BALF cells adhered to a cell culture substratum after erythromycin treatment of foals. Erythromycin A was not detected in plasma of any treated foal at the time of the second BAL; anhydroerythromycin A, a degradation product of erythromycin, was detected in plasma of 5 of 6 foals (mean concentration, 0.2 ± 0.06 µg/ml).

Conclusion and Clinical Relevance

BAL induces neutrophilic inflammation, which persists for at least 4 days in the lungs of young horses. Erythromycni (25 mg/kg, PO, q 12 h) diminishes this inflammatory response through a mechanism that may involve alteration of BALF cell function. Degradation of erythromycin to biologically active products or presence of parent drug in pulmonary secretions may be responsible for alterations in pulmonary lavage cell Chemotaxis and adherence. Erythromycin administered orally to foals at clinically relevant doses appears to have nonantimicrobial effects that may interfere with host cell metabolism and decrease inflammatory reponses in airways. (Am J Vet Res 1997;58:56–61)
Detection of antibodies to Salmonella lipopolysaccharide in muscle fluid from cattle
Authors: Hoorfar J. , Wedderkopp A. , Lind P.
Published: January 2024

Objective

To compare muscle fluid with serum samples for detection of antibodies to Salmonella lipopolysaccharide.

Sample Population

Muscle fluid and serum samples from 2 cattle populations: 1 from the island of Bornholm with no history of salmonellosis (n = 39), and the other from the S dublin-enzootic areas of Jutland (n = 144).

Procedure

Salmonella dublin (O:1,9,12), S typhimu-rium (O:1,4,5,12), and Salmonella O:9-blocking ELISA were used for testing the samples.

Results

In the S dublin ELISA, all serum and muscle fluid samples from cattle on the island of Bornholm had OD450 values well below the cutoff value (0.5). For samples obtained from cattle in the enzootic areas of Jutland, high correlation was found between serum and muscle fluid samples (rs = 0.89, P < 0.001). In addition, 19% (28/144) of the cattle had ELISA-positive muscle fluid and serum samples; 2% (3/144) had positive results for muscle fluid only, whereas 1 animal had positive results for serum only (κ = 0.91, P < 0.0001; sensitivity and specificity of 97%). The same samples had similar significant correlation in the S typhimurium ELISA (rs = 0.88, P < 0.001, κ = 0.7, P < 0.001; sensitivity of 73% and specificity of 98%) and the O:9-blocking ELISA (rs = 0.49, P < 0.001).

Conclusion and Clinical Relevance

Muscle fluid samples taken at slaughter can be used as a practical alternative to serum samples for surveillance of Salmonella infections in cattle. (Am J Vet Res I997;58;334-337)
Three-dimensional culture of canine articular chondrocytes on multiple transplantable substrates
Authors: Cook James L. , Kreeger John M. , Payne John T. , Tomlinson James L.
Published: January 2024

Objective

To determine the effects of transplantable substrates on canine chondrocytes grown in three-dimensional culture.

Animals

3 canine cadavers.

Procedure

Articular cartilage harvested from canine cadavers was used to obtain chondrocytes for primary culture. Subcultured chondrocytes were grown in agarose alone (AG), or in agarose on canine cancellous bone (CB), polypropylene mesh, or oxidized regenerated cellulose substrate. Cell proliferation, proteoglycan and glycosaminoglycan (GAG) production, and collagen production were assessed on days 3, 6, 10, 15 and 20.

Results

Chondrocytes from groups AG and CB proliferated and produced matrix over the entire 20-day study period. Group-CB chondrocytes had significantly more GAG than did chondrocytes of all other groups on days 6 (P = 0.0297) and 15 (P = 0.00272). Those of groups AG and CB contained significantly (P = 0.0235) more GAG on day 20. Chondrocytes of the polypropylene mesh group proliferated and produced matrix through day 10 in culture, but were no longer viable and had no matrix production on days 15 and 20. Regenerated cellulose appeared to be toxic to canine chondrocytes during all stages of in vitro three-dimensional culture.

Conclusions

Three-dimensional culture of canine chondrocytes in agarose appears to produce favorable results with respect to chondrocyte proliferation and matrix production. Canine CB appears to have beneficial effects with regard to early GAG synthesis. Polypropylene mesh and oxidized regenerated cellulose had detrimental effects on cellular proliferation and matrix production. (Am J Vet Res 1997;58:419–424)
Effect of transportation on the composition of bronchoalveolar lavage fluid obtained from horses
Authors: Hobo Seiji , Oikawa Masa-aki , Kuwano Atsutoshi , Yoshida Kohei , Yoshihara Toyohiko
Published: January 2024

Objective

To study the effects of extended transportation on the composition of bronchoalveolar lavage fluid (BALF) obtained from horses.

Animals

30 horses (14 males, 16 females; 25 Thoroughbreds and 5 Thoroughbred-Arabian crossbreds; 27 to 30 months old) without a history or clinical signs of respiratory tract disease. Bronchoalveolar lavage was performed on nontransported control horses (groups 1 and 2) and transported horses (group 3).

Procedure

20 horses were used to determine the effect of 41 hours of transportation on the composition of BALF (group 3). Bronchoalveolar lavage fluid was analyzed for recovered volume, number and distribution of nucleated cells, total protein and phospholipid concentrations, and phospholipid composition.

Results

Total number of nucleated cells in BALF from group-3 horses increased by approximately fourfold after transportation. Total protein concentration in BALF from group-3 horses also increased by approximately fivefold after transportation. Total phosphorus concentrations in group-3 horses decreased significantly from time 0 to immediately after transportation. In group-3 horses, the most characteristic change in composition of BALF after transport was a significant decrease in the concentration of phosphatidylglycerol.

Conclusion and Clinical Relevance

The decrease in phosphatidylglycerol concentration in BALF after transportation indicates a reduction in the quantity of surfactant. This change may reflect either a decreased production of surfactant by alveolar type II epithelial cells or an increased removal of surfactant from the alveolar region. It is likely that extended transportation resulted in a decreased concentration of surfactant in BALF. Such a decrease may reduce the pulmonary defence mechanisms in the alveolar region, possibly resulting in infection. (Am J Vet Res 1997;58:531–534)
Hyaluronate concentration in tracheal lavage fluid from clinically normal horses and horses with chronic obstructive pulmonary disease
Authors: Tulamo Riitta-Mari , Maisi Päivi
Published: January 2024

Objective

To establish concentration of hyaluronate (HA) in tracheal lavage fluid from healthy horses and horses with chronic obstructive pulmonary disease (COPD).

Animals and Samples

Tracheal lavage fluid samples (n = 42) from 18 horses, 11 with COPD, and 7 control horses.

Procedure

Clinical examination of the respiratory tract, tracheal lavage, and blood sample collection were performed on horses without clinical signs of respiratory tract disease and horses with clinical signs of COPD. In some horses, 1 to 5 repeated examinations were performed at 1-week intervals. Tracheal lavage fluid samples were analyzed for cell numbers, and urea concentration (made in parallel with serum samples to evaluate sample dilution effect); HA was determined by radiometric assay.

Results

Mean (± SEM) HA concentration in tracheal lavage fluid samples was significantly (P = 0.005) higher in horses with COPD (1,880 [± 309] μg/L), compared with that in control horses (256 [± 72] μg/L). The increase in HA concentration in tracheal lavage fluid of COPD-affected horses was verified by repeated sample collection and analysis.

Conclusions

In horses with chronic respiratory tract inflammation such as COPD, tracheal lavage fluid HA concentration is about 7 times higher than reference values. High HA concentration in the tracheal or bronchoalveolar lavage fluid may reflect pathophysiologic changes in connective tissue around bronchi and bronchioli, leading to continuous increased production of HA in horses with advanced forms of COPD.

Clinical Relevance

Determination of tracheal lavage fluid HA concentration may be used as a marker of chronic inflammatory changes in the COPD-affected lung. (Am J Vet Res 1997;58:729–732)
Effects of tromethamine buffer on coagulation variables and ionized calcium concentration in dogs
Authors: Moon P. F. , Barr S. C. , Erb H. N.
Published: January 2024

Objective

To evaluate coagulation variables in 2 groups of dogs after tromethamine administration.

Animals

13 Beagles.

Procedures

Both groups of dogs received a 30-minute IV infusion of 10 ml of 0.3M tromethamine/kg of body weight. In unsedated dogs (group 1, n = 8), prothrombin time, activated partial thromboplastin time, normalized ionized calcium concentration, platelet numbers, and platelet function were measured prior to treatment, at the end of the infusion, and 1 hour after the infusion. In xylazine-sedated dogs (group 2, n = 5), buccal mucosal bleeding time and plasma percentage of von Willebrand factor antigen were measured before and 1 hour after infusion, and fibrin degradation products concentration was measured 1 hour after infusion. Platelet function was assessed by determining platelet aggregation and by measuring ATP release from the aggregating platelets over 6 minutes, using a whole blood aggregometer, with 20, 10, and 5 μM ADP and 5 and 10 μg of collagen/ml as platelet activation agonists.

Results

There was no significant change in any of the variables measured in either group of dogs, compared with baseline values.

Conclusions and Clinical Relevance

When administered to healthy dogs, tromethamine does not change the coagulation indices measured. (Am J Vet Res 1997;58:777–780)
Comparison of nested polymerase chain reaction, virus isolation, and fluorescent antibody testing for identifying feline herpesvirus in cats with conjunctivitis
Authors: Stiles Jean , McDermott Michelle , Willis Michelle , Roberts Wayne , Greene Craig
Published: January 2024

Objective

To compare nested polymerase chain reaction (PCR), virus isolation (VI), and fluorescent antibody (FA) testing to detect feline herpesvirus (FHV) in cats with naturally acquired conjunctivitis or respiratory tract disease, or both.

Samples

Swab and microbrush specimens from the conjunctiva and throat were taken from 46 cats, allotted to 3 groups (conjunctivitis only, respiratory tract disease and conjunctivitis, and clinically normal).

Procedure

Cells from microbrush specimens were digested and herpesvirus DNA was amplified, using a double round of PCR. Products were detected by use of agarose gel electrophoresis. The VI and FA tests were performed in routine manner.

Results

Of 16 cats with conjunctivitis only, conjunctival specimens from 8 and throat specimens from 8 were FHV positive by PCR. None had positive results of VI or FA testing. Of 15 cats with respiratory tract disease and conjunctivitis, conjunctival specimens from 13 and throat specimens from 12 were FHV positive by PCR. A conjunctival specimen from 1 cat and throat specimens from 3 cats were FHV positive by VI. A conjunctival specimen from 1 cat was FHV positive by FA testing. Of 15 clinically normal cats, conjunctival and throat specimens from 2 cats were FHV positive by PCR; neither conjunctival nor throat specimens from these cats were FHV positive by VI or FA testing.

Conclusion

For cats with respiratory tract disease and conjunctivitis, or with conjunctivitis only, nested PCR was more sensitive at detecting FHV than was VI or FA testing.

Clinical Relevance

Nested PCR is a more sensitive test than the currently available VI and FA tests for identifying FHV in cats with conjunctivitis. (Am J Vet Res 1997;58:804–807)
Distribution of glycoconjugates in the uterine tube (oviduct) of horses
Authors: Ball Barry A. , Dobrinski Ina , Fagnan Molly Sue , Thomas Philip G. A.
Published: January 2024

Objective

To examine glycoconjugates in the isthmic and ampullar regions of the uterine tube (oviduct) of horses during estrus, diestrus, and pregnancy.

Sample Population

Oviductal samples from 17 mares.

Procedure

Oviducts were collected during estrus (n = 3), diestrus (n = 3), or pregnancy (n = 3), embedded, and snap frozen in liquid nitrogen. Frozen sections (5 to 6 μm in thickness) were stained with 100 μg/ml of fluorescein-isothiocyanate-conjugated lectin (30 min at 38.5 C) and were evaluated by use of epifluorescence microscopy and video image analysis. Specificity of lectins was established by blocking with the corresponding carbohydrate. Dolichos biflorus agglutinin (DBA)-affinity studies on western blots of oviductal lavage fluid, oviductal explant conditioned media, and apical membrane proteins from isthmic and ampullar regions of oviducts were used to identify glycoproteins with galactosyl residues.

Results

Use of 4 lectins resulted in differential labeling of the luminal surface of the oviductal epithelium. Both DBA and soybean agglutinin labeled the apical epithelium of the isthmus, but not the ampullar oviduct. Soybean agglutinin resulted in more-intensely labeled epithelium in the isthmic region of oviducts during estrus and pregnancy than during diestrus. The DBA labeled a number of glycoproteins in conditioned media from both regions of the oviduct. These glycoproteins ranged from 14 to 200 kd, with major glycoproteins identified at 31 and 57 kd.

Conclusions

The predominant glycoconjugates in the oviduct of horses are galactosyl residues. There are regional differences in the distribution of these galactosyl glycoconjugates in the isthmic and ampullar oviduct. (Am J Vet Res 1997;58:816–822)
Effect of combined staphylectomy and laryngotomy on upper airway mechanics in clinically normal horses
Authors: O'Rielly Jennette L. , Beard Warren L. , Renn Timothy N. , Padden Andrew J. , Hinchcliff Kenneth W.
Published: January 2024

Objective

To investigate the effect of combined staphylectomy and laryngotomy on upper airway mechanics in clinically normal horses running on a treadmill.

Animals

6 Standardbreds.

Procedure

Upper airway mechanics were measured with horses trotting or pacing on a treadmill at 5, 8, and 10 m/s before and 6 weeks after combined staphylectomy and laryngotomy. Pharyngeal and tracheal inspiratory and expiratory pressure were measured by use of transnasal tracheal and pharyngeal side hole catheters connected to differential pressure transducers. A pneumotachograph mounted on the rostral end of an airtight face mask was used to measure airflow.

Results

Upper airway and translaryngeal inspiratory impedances were higher, respiratory rate was decreased, and inspiratory time was longer (P < 0.05) at all speeds after staphylectomy and laryngotomy.

Conclusion

Combined staphylectomy and laryngotomy significantly affects upper airway mechanics in clinically normal horses.

Clinical Relevance

Because combined staphylectomy and laryngotomy exerts a potentially adverse effect on upper airway mechanics in clinically normal horses, the procedure should only be performed when it is clearly indicated. (Am J Vet Res 1997;58:1018–1021)
Ultrasound biomicroscopy of globes from young adult pigs
Authors: Bartholomew L. R. , Pang D. X. , Sam D. A. , Cavender J. C.
Published: January 2024

Objective

To determine anterior chamber ocular measurements of adult porcine globes without histologic fixation by use of ultrasound biomicroscopy scanning.

Sample Population

25 porcine globes obtained at an abattoir.

Procedure

Globes were packed on ice for transport. In the laboratory, globes were trimmed, rinsed with antibiotic solution, secured on a single gauze-fold in a latex holder, then were ultrasonogrammed unreformed. Ultrasound biomicroscopy scanning was done, using a 50-MHz transducer, 17-mm cup, and 2% methyl cellulose.

Results

Average young adult pig external ocular measurements were: nasal-temporal corneal diameter, 16.61mm; superior-inferior corneal diameter, 14.00 mm; nasal-temporal globe diameter, 25.48 mm; superior-inferior globe diameter, 24.48 mm; and axial length 21.64 mm. Ultrasound biomicroscopy anterior chamber measurements were: iris sulcus, 30.45°; ciliary sulcus, 18.89°; central corneal thickness, 0.98 mm; corneal thickness at limbus, 1.19 mm; central iris thickness, 0.58 mm; iris tip to ciliary apex, 1.73 mm; iris tip to iris sulcus origin, 3.83 mm; iris tip to ciliary sulcus origin, 2.98 mm; anterior chamber depth from iris tip to cornea, 2.21 mm; central anterior chamber depth, 2.47 mm; ciliary process mid-thickness, 0.65 mm; ciliary process apex to origin of iris sulcus, 2.32 mm; ciliary process apex to origin of ciliary sulcus, 1.34 mm; zonular bundle diameter, 0.10 mm; and interzonular bundle space, 0.11 mm.

Conclusions

Anatomic anterior chamber measurements and relations in porcine globes can be used to describe trauma, confirm existence of lesions, and help explain theory.

Clinical Relevance

Ultrasound biomicroscopy is a clinical decision aid facilitating noninvasive anatomic or pathologic description without histologic fixation. (Am J Vet Res 1997;58:942–948)
Comparison of the PK(15)- and WEHI 164 (clone 13)-based bioassays for detection of porcine tumor necrosis factor
Authors: Boury Nancy Maroushek , Stabel Thomas J. , Kehrli Marcus , Taylor Michael
Published: January 2024

Objective

To determine relative sensitivities of the PK(15)- and WEHI 164(13)-based bioassays for detection of tumor necrosis factor α (TNF).

Sample Population

Recombinant human, murine, and porcine TNF, and serum from pigs given endotoxin IV.

Procedure

Two cell lines were used as targets for recombinant human, murine, and porcine TNF cytotoxicity bioassays. Pigs were given sublethal doses of endotoxin to obtain serum samples containing high activity of porcine TNF. Serum TNF activity was tested, using both cell lines. Viable cells were detected by addition of dimethylthiazol diphenyltetrazolium bromide after 18 to 20 hours’ incubation with samples containing TNF.

Results

The 2 cell lines tested had different sensitivities to human, murine, and porcine TNF. Compared with WEHI 164(13) cells, PK(15) cells were 50 times less sensitive to murine TNF and 15 times less sensitive to human TNF. However, PK(15) cells were 4 times more sensitive to recombinant porcine TNF and 15 times more sensitive to porcine serum containing TNF.

Conclusions

The PK(15) cell line was more sensitive to porcine TNF-mediated lysis than was the WEHI 164(13) cell line. The PK(15)-based TNF bioassay will be especially useful for study of infectious disease processes in swine, particularly where low activity of TNF exists. (Am J Vet Res 1997;58:1115–1119)
Effects of intravenous administration of sodium hyaluronate on carpal joints in exercising horses after arthroscopic surgery and osteochondral fragmentation
Authors: Kawcak C. E. , Frisbie D. D. , Trotter G. W. , McIlwraith C. W. , Gillette S. M. , Powers B. E. , Walton R. M.
Published: January 2024

Objective

To evaluate the effects of arthroscopic surgery, osteochondral fragmentation, and treatment with IV administered hyaluronate on histologic, histochemical, and biochemical measurements within the carpal joints of horses.

Animals

12 clinically normal horses, 2 to 7 years of age.

Procedure

Horses had an osteochondral fragment created at the distal aspect of the radiocarpal bone of 1 randomly chosen middle carpal joint to simulate osteochondral fragmentation. Horses were treated with 40 mg of hyaluronate or saline solution (placebo) intravenously once a week for 3 consecutive weeks (days 13, 20, and 27 after surgery). Treadmill exercise proceeded 5 days per week beginning 15 days, and ending 72 days, after surgery. Clinical evaluations were performed at the beginning and end of the study. Synovial fluid samples were obtained aseptically from both middle carpal joints on days 0, 13, 20, 27, 34, and 72 after surgery, and total protein, inflammatory cell, hyaluronate, glycosaminoglycan, and prostaglandin E2 concentrations were measured in each sample. All horses were euthanatized on day 72. Synovial membrane and articular cartilage were obtained for histologic evaluation. Articular cartilage samples were also obtained aseptically for determining glycosaminoglycan content and chondrocyte synthetic rate for glycosaminoglycans.

Results

Horses treated with hyaluronate intravenously had lower lameness scores (were less lame), significantly better synovial membrane histologic scores, and significantly lower concentrations of total protein and prostaglandin E2 within synovial fluid 72 days after surgery, compared with placebo-treated horses. Treatment with intravenously administered hyaluronate had no significant effects on glycosaminoglycan content, synthetic rate or morphologic scoring in articular cartilage, or other synovial fluid measurements.

Conclusion

Intravenously administered hyaluronate appears to alleviate signs of lameness by interacting with synoviocytes, and by decreasing production and release of inflammatory mediators. (Am J Vet Res 1997;58:1132–1140)
Isolation and expression of a porcine lactoferrin gene
Authors: Wang Shih-Rong , Lin Tsai-Yun , Chen Chi-Ming , Weng Chung-Nan
Published: January 2024

Objective

To elucidate the spatial and temporal expression of a porcine lactoferrin (LTF) gene.

Animals

4 female and 4 male Large White pigs.

Procedures

We examined LTF expression in various organs excised from the pigs, using northern blot hybridization with a porcine LTF cDNA probe. Antibodies against porcine LTF were raised in rabbits and were used along with immunohistochemical staining to localize the LTF protein.

Results

High amounts of porcine LTF mRNA were detected in the secreting mammary gland and epididymis. This distribution is consistent with that of porcine LTF examined by immunohistochemistry. In female pigs, porcine LTF mRNA concentration increased remarkably in the ductal cells of the lactating mammary gland then significantly decreased at day 21 after parturition. Furthermore, specific staining for LTF was observed in the epithelial cells of the gastrointestinal tract of female pigs, but not in the uterus, ovaries, spleen, kidneys, pancreas, muscles, heart, brain, lungs, or liver of postpartum female pigs, or in the testes of male pigs.

Conclusions

Gene expression of porcine LTF is closely related to lactation in the mammary gland. Distribution of LTF in the epididymis suggests that LTF may have a regulatory role in development of the reproductive tract of male pigs. (Am J Vet Res 1997;58:1152–1158)
Effects of postoperative peritoneal lavage on pharmacokinetics of gentamicin in horses after celiotomy
Authors: Easter J. Lane , Hague Brent A. , Brumbaugh Gordon W. , Nguyen John , Chaffin M. Keith , Honnas Clifford M. , Kemper Deborah L.
Published: January 2024

Objective

To evaluate the effect of peritoneal lavage on pharmacokinetics of gentamicin sulfate in healthy horses after experimental celiotomy.

Animals

13 clinically normal horses.

Procedure

Horses were randomly assigned to control or experimental groups. All horses received gentamicin (6.6 mg/kg of body weight, IV, q 24 h) before surgery, underwent experimental abdominal surgery, and had abdominal drains placed percutaneously. Horses of the experimental group received postoperative peritoneal lavage; horses of the control group did not receive peritoneal lavage. The day after surgery, 24 hours after the preoperative dose of gentamicin, a second dose of gentamicin was administered. Three and 15 hours after this second dose of gentamicin, horses of the experimental group received peritoneal lavage. Venous blood was obtained, for determination of concentration of gentamicin, immediately before and at specified intervals during the 24-hour period after the second dose of gentamicin.

Results

There were no differences in any of the pharmacokinetic values of gentamicin between horses of the control and experimental groups.

Conclusions

Peritoneal lavage had no effect on pharmacokinetics of gentamicin in healthy horses after abdominal surgery, in which localized nonseptic peritonitis was induced.

Clinical Relevance

Peritoneal lavage in horses with localized nonseptic peritonitis or for the prevention of intra-abdominal adhesions should not necessitate alteration of the dosage of gentamicin to maintain predictable serum concentrations. (Am J Vet Res 1997;58:1166–1170)
Metabolizable energy intake and sustained energy expenditure of Alaskan sled dogs during heavy exertion in the cold
Authors: Hinchcliff Kenneth W. , Reinhart Gregory A. , Burr John R. , Schreier Curt J. , Swenson Richard A.
Published: January 2024

Objective

To measure energy expenditures of Alaskan sled dogs at rest and during racing under frigid conditions, using the doubly labeled water (DLW) technique.

Animals

18 fit Alaskan sled dogs.

Procedure

Energy expenditure was measured in 9 dogs during a 490-km sled dog race by use of the DLW technique, whereby dogs were administered water enriched with nonradioactive isotopes of hydrogen and oxygen. Energy intake was determined by dietary analysis. Changes in background abundance of the isotopes 2H and 18O were monitored in 5 dogs that did not receive isotope-enriched water.

Results

Dogs completed the 490-km race at an average speed of 7 km/h at ambient temperature of −35 to −10 C. Total energy expenditure, measured by the DLW technique, was 47,100 ± 5,900 kJ/d (4,400 ± 400 kJ·kg-0.75/d), and metabolizable energy intake was 44,600 kJ/d (4,100 kJ·kg-0.75/d) during the 70-hour race.

Conclusions

The sustained metabolic rate for these sled dogs during racing was extraordinarily high for a large mammal. This study validated use of the DLW technique in dogs with exceptionally high energy expenditure associated with prolonged exercise in the cold. (Am J Vet Res 1997;58:1457–1462)
Immunocytochemical differences in adenohypophyseal cells among adult Mongolian pony mares, stallions, and geldings
Authors: Tan J. H. , Nanbo Y. , Oikawa M. , Kiso Y. , Sasaki F.
Published: January 2024

Objective

To analyze the sex difference in 6 kinds of adenohypophyseal cells of Mongolian ponies and the effect of prepubertal orchidectomy on adenohypophyseal cells.

Sample Population

Pituitary glands collected from 15 adult Mongolian ponies, 5 to 10 years old: 5 stallions, 5 mares, and 5 geldings, orchidectomized between the ages of 1 and 2 years.

Procedure

Morphologic comparison of 6 kinds of adenohypophyseal cells among mares, stallions, and geldings was done, using immunocytochemistry and morphometry.

Results

A sex difference was evident in the percentage of somatotrophs, gonadotrophs (follicle-stimulating hormone [FSH] and luteinizing hormone [LH] cells), and lactotrophs in adult ponies: somatotrophs were more numerous (P = 0.0003) in stallions (approx 40%) than in mares (approx 25%), whereas FSH and LH cells and lactotrophs were more numerous (P = 0.0116, P = 0.0044, P = 0.0085, respectively) in mares (approx 10, 20, and 24%, respectively) than in stallions (approx 6, 15, and 15%, respectively). Prepubertal orchidectomy markedly reduced the proportion of somatotrophs (approx 28%; P = 0.0016) and increased that of lactotrophs (approx 22%; P = 0.0318) in geldings, compared with stallions. The LH cell area was larger in mares than stallions (P < 0.0001). Prepubertal orchidectomy increased FSH (P = 0.0005) and LH (P < 0.0001) cell areas in adult geldings, compared with stallions.

Conclusions

A sex difference exists in adenohypophyseal cells of adult ponies: somatotrophs are more abundant in stallions; FSH and LH cells and lactotrophs are more abundant in mares. Our data indicate that equine testes during postnatal life may stimulate development of GH cells while suppressing development of FSH and LH cells and lactotrophs. The effects of prepubertal orchidectomy on pony somatotrophs and lactotrophs differ greatly from effects on those cells in mice. (Am J Vet Res 1998;59:262–266)
Genetic test for myophosphorylase deficiency in Charolais cattle
Authors: Bilstrom Jessica A. , Valberg Stephanie J. , Bernoco Domenico , Mickelson James R.
Published: January 2024

Objective

To develop a simple test for the determination of genetic susceptibility to myophosphorylase deficiency in Charolais cattle.

Animals

48 adult Charolais cattle and 233 calves from one herd and 3 Charolais cattle from 2 other herds. Sixty Piedmontese and 34 Saler cattle provided negative-control samples.

Procedure

Cattle were from a Charolais herd in which myophosphorylase deficiency was identified and 2 other herds in which cattle had signs compatible with the disease. Genomic DNA was isolated from heparinized blood samples. A segment of the myophosphorylase gene containing the mutation site was amplified by polymerase chain reaction assays, and the genotype (normal vs affected allele) was determined by using restriction enzyme and agarose gel electrophoretic analysis.

Results

The 3 myophosphorylase genotypes (homozygous normal, homozygous affected, and heterozygous) could be readily identified. Segregation of the affected allele could be determined in an extended pedigree, and all clinically affected cattle were homozygous for this allele. Determination of the distribution of normal and affected alleles in a large population did not indicate a strong selective advantage for heterozygous carriers in this herd. Heterozygotes were also identified in Charolais cattle from the 2 other herds.

Conclusions

Breeders of Charolais cattle can use this genetic test to perform marker-assisted selection and remove cattle with the mutant myophosphorylase allele from the breeding population. Alternatively, they could more accurately determine selective advantages and disadvantages for cattle with the affected allele.

Clinical Relevance

Development of this test enables rapid genetic screening of Charolais and related breeds of cattle for detection of the mutation responsible for myophosphorylase deficiency. (Am J Vet Res 1998;59:267–270)
Biochemical and ribotypic comparison of Actinomyces pyogenes and A pyogenes-like organisms from liver abscesses, ruminal wall, and ruminal contents of cattle
Authors: Narayanan Sanjeevkumar , Nagaraja T. G. , Wallace Neil , Staats Jacque , Chengappa M. M. , Oberst R. D.
Published: January 2024

Objective

To isolate Actinomyces pyogenes and A pyogenes-like (APL) organisms from the ruminal wall and ruminal contents of cattle and compare them with isolates from liver abscesses from the same animals, using ribosomal DNA restriction fragment length polymorphism analysis or ribotyping.

Procedure

Specimens of liver abscesses, ruminal walls, and ruminal contents were collected from 59 cattle at slaughter. All β-hemolytic, pinpoint colonies that were gram positive, pleomorphic rod-shaped, and catalase negative, and that hydrolyzed casein and gelatin were presumptively identified as A pyogenes and were characterized biochemically, using an identification kit. The isolates that resembled A pyogenes but fermented mannitol or raffinose, or both, were called APL organisms. Isolates from the ruminal wall and ruminal contents were compared with liver abscess isolates from the same animal by use of ribotyping.

Results

Actinomyces pyogenes and APL organisms were isolated more frequently from the ruminal wall than from ruminal contents. Ruminal isolates of A pyogenes and APL had biochemical characteristics similar to those of the isolates from liver abscesses. Among 6 sets of isolates (4 A pyogenes and 2 APL), 2 isolates from liver abscesses had ribopatterns identical to the corresponding ruminal wall isolates. Also, the APL organisms isolated from the ruminal content matched with the corresponding liver abscess isolates for both sets of specimens tested.

Conclusions

The ruminal wall may be the niche for A pyogenes and APL organisms in the rumen. The genetic similarity, on the basis of ribotyping among isolates from liver abscesses, the ruminal wall, and ruminal contents of the same animal suggests that A pyogenes and APL organisms that cause liver abscesses originate from the rumen. (Am J Vet Res 1998;59:271–276)
Effect of synovial membrane infection in vitro on equine synoviocytes and chondrocytes
Authors: Hardy J. , Bertone A. L. , Malemud C. J.
Published: January 2024

Objective

To determine the functional response of synovium to infection, and the influence of infected synovium on articular cartilage metabolism.

Sample Population

Synovium and articular cartilage explants from the midcarpal and tarsocrural joints of adult horses.

Procedure

For experiment 1, synovium explants were incubated as follows: control—incubation in standard medium, infected (I)—incubation with Staphylococcus aureus, and infected-filtered (IF)—incubation with medium collected from the infected group and filtered (0.22-μm filter). Daily collected medium was assayed for interleukin 1β (IL-1β), IL-6, tumor necrosis factor, and hyaluronan (HA) concentrations. For experiment 2, cartilage explants were incubated as follows: control—incubation in standard medium, and IF—incubation in medium collected from infected synovium cultures and filtered. After 48 hours, explant proteoglycan synthesis and endogenous proteoglycan and glycosaminoglycan contents were determined.

Results

IL-1β and IL-6 values were significantly increased in synovium explants from the I and IF groups. Hyaluronan concentration was lower in I and IF groups. Proteoglycan synthesis and content, and total glycosaminoglycan and chondroitin sulfate concentrations, were significantly decreased in cartilage from the IF group.

Conclusions

Bacterial infection was associated with decreased HA concentration and increased mediator release. These effects were also observed despite elimination of bacteria. Exposure to sterile but previously infected medium decreased articular cartilage matrix synthesis and composition.

Clinical Relevance

Resident synovial cells may contribute appreciably to articular damage during bacterial infection in the absence of migrant inflammatory cells. This response is prolonged despite elimination of the bacteria. (Am J Vet Res 1998;59:293–299)
Expression of c-kit and stem cell factor mRNA in liver specimens from healthy adult dogs
Authors: Morimoto Masahiro , Tsujimura Tohru , Kanakura Yuzuru , Kitamura Yukihiko , Matsuda Hiroshi
Published: January 2024

Objective

To determine expression of c-kit and stem cell factor (SCF) mRNA in liver specimens from healthy adult dogs and to investigate whether differentiation of mast cells in the liver of dogs is supported by the c-kit receptor tyrosine kinase/SCF system.

Animals

3 healthy adult Beagles.

Procedure

The nucleic acid sequence of the canine c-kit fragment of the intracellular tyrosine kinase domain was determined. Magnitudes of c-kit and SCF mRNA expression in liver samples was determined by means of northern blot analysis, using probes based on canine sequences. To determine which cells were expressing c-kit and SCF mRNA, in situ hybridization was performed.

Results

Expression of c-kit and SCF mRNA in liver samples was weak but appreciable. In situ hybridization revealed that c-kit and SCF mRNA expression was restricted to mast cells and plasma cells, respectively.

Conclusion

Expression of SCF mRNA was detected in liver from healthy adult dogs. The c-kit receptor tyrosine kinase/SCF system may, possibly in combination with other growth factor and receptor systems, be involved in proliferation and differentiation of liver mast cells in dogs. (Am J Vet Res 1998;59:363–366)