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Abstract

Objective—To describe the ultrasonographic and quantitative histologic effect of injecting 2% iodine in almond oil (IAO) and ethanolamine oleate (EO) in the medial and middle patellar ligaments of horses and to determine whether a difference in response exists between IAO and EO treatment.

Animals—10 healthy horses.

Procedure—In 5 horses, the medial and middle patellar ligaments of 1 limb were injected with EO, whereas IAO was injected in the medial and middle patellar ligaments of another 5 horses. Ultrasonographic evaluation was performed on the experimental and control limb before injection of IAO and EO and prior to euthanasia to determine cross-sectional area and evaluate fiber pattern. The patellar ligaments were harvested 2 weeks after injection and examined histologically to evaluate the inflammatory response, fibroplasia, and chondroid metaplasia.

Results—Injection of the patellar ligaments with IAO resulted in a greater increase in cross-sectional area on ultrasonography than EO. Both agents caused a decrease in echogenicity of the ligament. Histologically, significantly greater infiltration of inflammatory cells and fibroplasia developed after injection with IAO, compared with EO. Both agents resulted in significantly greater fibroplasia relative to control specimens.

Conclusions and Clinical Relevance—Injection of the medial and middle patellar ligaments with IAO induces more severe inflammation and fibroplasia than EO. Maturation of the inflammatory and fibrous response may contribute to resolution or attenuation of upward fixation of the patella by subsequent stiffening of the ligaments. (Am J Vet Res 2002;63:738–743)

Full access
in American Journal of Veterinary Research

Abstract

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)

Free access
in American Journal of Veterinary Research

SUMMARY

The compound nerve action potential (cnap) of the superficial peroneal nerve of dogs was investigated to determine: (1) the influence of the stimulation technique on the configuration of the cnap, with particular attention to late components; (2) the fiber diameter (fd) distribution; and (3) the relationship between fd distribution and cnap configuration, by reconstruction of cnap made on the basis of fd distributions.

The cnap were evoked in 9 dogs under halothane anesthesia by 2 stimulation methods: percutaneous needle electrode stimulation and direct stimulation of the exposed superficial peroneal nerve. Recordings were made with percutaneous needle electrodes. Full nerve cross sections of 7 superficial peroneal nerves were prepared for fd morphometric analysis. Reconstruction of cnap were made on the basis of the fd distributions.

Late components of the cnap could be evoked with either stimulation method, but only with a stimulus intensity of 3 to 5 times maximal for the main (early) component of the cnap. The fd histograms of 7 analyzed nerves had bimodal distribution. In 5 nerves, peaks were at 4.2 to 4.5 μm and 9.0 to 10.0 μm, with 60% of the fibers in the small-diameter group. In 2 nerves with lower maximal conduction velocities, peaks were shifted toward smaller values.

The cnap reconstructions made by use of fd data closely resembled actual recordings when a fifth-order polynomial function was applied to the relationship between nerve conduction velocity and fd. Reconstructions made by use of 1 or 2 linear functions did not accurately resemble actual recordings.

The results indicate clinical sensory electroneurographic recordings can provide accurate information regarding both large- and small-diameter fibers, if adequate stimulus intensities are used. To understand the recorded potential more completely, further studies are needed to determine the effects of volume conduction on configuration of the cnap. It should then be possible to estimate fd distributions even more accurately by analyzing cnap of normal nerves, or of diseased nerves in which the normal relation between fd and conduction velocity is preserved.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate changes in cysteinyl leukotriene (LT) concentrations in urine and bronchoalveolar lavage fluid (BALF) in cats with experimentally induced asthma.

Animals—19 cats with experimentally induced asthma and 5 control cats.

Procedure—Cats were sensitized to Bermuda grass or house dust mite allergen, and phenotypic features of asthma were confirmed with intradermal skin testing, evaluation of BALF eosinophil percentages, and pulmonary function testing. A competitive ELISA kit for LTC4, LTD4, and LTE4 was used for quantitative analysis of LTs. Urinary creatinine concentrations and BALF total protein (TP) concentrations were measured, and urinary LT-to-creatinine ratios and BALF LTto- TP ratios were calculated.

Results—Mean urinary LT-to-creatinine ratios did not differ significantly between control cats and allergensensitized cats before or after sensitization and challenge exposure with saline (0.9% NaCl) solution or allergen, respectively. In BALF, the mean LT-to-TP ratio of control cats did not differ significantly before or after sensitization and challenge exposure with saline. Asthmatic cats had BALF LT-to-TP ratios that were significantly lower than control cats at all time points, whereas ratios for asthmatic cats did not differ significantly among the various time points.

Conclusions and Clinical Relevance—Although LTs were readily detectable in urine, no significant increases in urinary LT concentrations were detected after challenge in allergen-sensitized cats. Spot testing of urinary LT concentrations appears to have no clinical benefit for use in monitoring the inflammatory asthmatic state in cats. The possibility that cysteinyl LTs bind effectively to their target receptors in BALF and, thus, decrease free LT concentrations deserves further study. (Am J Vet Res 2003;64:1449–1453)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To compare the effects of an orally administered corticosteroid (prednisone), an inhaled corticosteroid (flunisolide), a leukotriene-receptor antagonist (zafirlukast), an antiserotonergic drug (cyproheptadine), and a control substance on the asthmatic phenotype in cats with experimentally induced asthma.

Animals—6 cats with asthma experimentally induced by the use of Bermuda grass allergen (BGA).

Procedures—A randomized, crossover design was used to assess changes in the percentage of eosinophils in bronchoalveolar lavage fluid (BALF); airway hyperresponsiveness; blood lymphocyte phenotype determined by use of flow cytometry; and serum and BALF content of BGA-specific IgE, IgG, and IgA determined by use of ELISAs.

Results—Mean ± SE eosinophil percentages in BALF when cats were administered prednisone (5.0 ± 2.3%) and flunisolide (2.5 ± 1.7%) were significantly lower than for the control treatment (33.7 ± 11.1%). We did not detect significant differences in airway hyperresponsiveness or lymphocyte surface markers among treatments. Content of BGA-specific IgE in serum was significantly lower when cats were treated with prednisone (25.5 ± 5.4%), compared with values for the control treatment (63.6 ± 12.9%); no other significant differences were observed in content of BGA-specific immunoglobulins among treatments.

Conclusions and Clinical Relevance—Orally administered and inhaled corticosteroids decreased eosinophilic inflammation in airways of cats with experimentally induced asthma. Only oral administration of prednisone decreased the content of BGAspecific IgE in serum; no other significant local or systemic immunologic effects were detected among treatments. Inhaled corticosteroids can be considered as an alternate method for decreasing airway inflammation in cats with asthma. (Am J Vet Res 2005;66:1121–1127)

Full access
in American Journal of Veterinary Research