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  • Author or Editor: Alan H. Brightman x
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SUMMARY

Tear samples were collected from 1 eye of each of 40 cows, 27 sheep, 5 goats, and 5 human beings. Additionally, 10 bovine tear samples were pooled and concentrated. Spectrophotometric assays, using Micrococcus lysodeikticus, were performed on each sample to detect lysozyme activity expressed in hen egg lysozyme (hel) equivalents. Lysozyme activity was not detected in tears of cows, but 158.8 ± 159.3 mg of hel/ml was detected in tears of sheep, 220.7 ± 37.5 mg of hel/ml in tears of goats, and 216.3 ± 86.2 mg of hel/ml in tears of human beings.

In pooled bovine tear samples, lysozyme activity was not detected on plate assay and lysozyme protein was not detected on Polyacrylamide gel electrophoresis, column chromatography, or immunoelectrophoresis with rabbit anti-bovine tear antibodies. On the basis of these observations, we concluded that the basic ocular protective mechanism in bovine tears is not lysozyme. Other antibacterial proteins such as lactoferrin, transferrin, complement, or β-lysin may, therefore, be of primary importance in protecting the bovine eye.

Free access
in American Journal of Veterinary Research

Summary

A total of 147 cats positive for FeLV were retrospectively studied to determine the incidence of ocular disease. Of those cats, 97 had clinical cases of the disease and 50 were artificially infected with the virus. The incidence of ocular disease among FeLV-positive cats with clinical signs of disease was less than 2%, and represented less than 0.1% of the total feline cases for the 5-year period studied. The only ocular findings that could be associated with FeLV were pupillary and motility abnormalities. Retinal hemorrhage and subsequent degeneration found in experimentally infected and naturally infected cats were secondary to profound anemia, which was secondary to FeLV infection. On the basis of the literature and our findings, FeLV is not a major cause of primary or secondary ocular disease in the cat. Anterior uveal disease (iris bombé) was detected in 1 of 147 FeLV-positive cats, and the incidence of secondary infectious disease was zero.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective

To determine whether bovine tear film contains the iron-binding glycoprotein, lactoferrin.

Animals

40 Adult Hereford, Angus, and Simmental cattle.

Procedure

Protein analysis: pooled bovine tears were used for protein analysis (size exclusion high-performance liquid chromatography [HPLC] fractionation). HPLC was used for tear analysis. A diode array detector was used (215 and 280 μm) for chromatogram analysis and comparisons.

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE): protein electrophoresis was performed, using 7.5% running gels with 4% stacking gels. Molecular weight of proteins in the unknown samples was determined as recommended by the manufacturer of the standards.

Protein sequencing: amino acid sequencing, using automated Edman degradation of HPLC purified protein, was performed. The sequence obtained was compared with the known protein sequence of bovine lactoferrin.

Results

HPLC analysis of whole bovine tears resulted in a consistent chromatogram. Peak collection was performed to recover a protein from the bovine tear film with chromatogram characteristics nearly identical to purified bovine lactoferrin. Silver-stained SDS-PAGE of this peak revealed a band with molecular mass consistent with bovine lactoferrin (estimated mass of 78 kd). The first 13 amino acid residues of this protein were identical to the amino acid sequence of bovine lactoferrin.

Conclusion

Analysis of whole bovine tears, using size exclusion HPLC, SDS-PAGE, and amino acid sequencing, provided evidence that bovine tears contain lactoferrin.

Clinical Relevance

Lactoferrin probably exerts a bacteriostatic effect in bovine tear film. Locally produced lactoferrin may bathe the ocular surface and sequester iron from potential pathogens. (Am J Vet Res 1996;57:1369-1372)

Free access
in American Journal of Veterinary Research

Objective

To establish ocular characteristics, determine nature and prevalence of ocular lesions, and identify representative bacterial flora from the conjunctiva of North American bison (Bison bison).

Design

Prospective study.

Animals

63 bison; 45 males and 18 females.

Procedure

Ophthalmic examinations were performed on 1 group of 38 bison in December 1997 and on a second group of 25 in March 1998. Eyes were examined with a penlight, magnification loop, and indirect ophthalmoscope. Two culture swabs were used to obtain samples from the inferior conjunctival sac. One swab was submitted for isolation of bacteria and the second was submitted for isolation of Mycoplasma organisms.

Results

15 ocular abnormalities were observed in 13 of the 63 bison. These included minor ocular discharge in 5 animals, 1 eyelid laceration, 1 periocular Demodex spp infection, 6 corneal abnormalities, 1 anterior synechia, and 1 cataract. Seventeen species of bacteria were isolated from the 63 swabs submitted for culture. The most prevalent bacteria were of the genus Bacillus (74.6%). Mycoplasma organisms were not observed.

Conclusions and Clinical Relevance

Corneal abnormalities were the most frequently identified ocular lesions in bison. Bacterial flora of the conjunctiva and ocular characteristics were similar to those reported for cattle. (J Am Vet Med Assoc 1999;215:1142–1144)

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate lactoferrin and lysozyme content in various ocular glands of bison and cattle and in tears of bison.

Sample Population—Tissues of ocular glands obtained from 15 bison and 15 cattle and tears collected from 38 bison.

Procedure—Immunohistochemical analysis was used to detect lysozyme and lactoferrin in formalin-fixed, paraffin-embedded sections of the ocular glands. Protein gel electrophoresis was used to analyze ocular glands and pooled bison tears by use of a tris-glycine gel and SDS-PAGE. Western blotting was used to detect lactoferrin and lysozyme.

Results—Immunohistochemical staining for lactoferrin was evident in the lacrimal gland and gland of the third eyelid in cattle and bison and the deep gland of the third eyelid (Harder's gland) in cattle. Equivocal staining for lactoferrin was seen for the Harder's gland in bison. An 80-kd band (lactoferrin) was detected via electrophoresis and western blots in the lacrimal gland and gland of the third eyelid in cattle and bison, Harder's glands of cattle, and bison tears. An inconsistent band was seen in Harder's glands of bison. Lysozyme was not detected in the lacrimal gland of cattle or bison with the use of immunohistochemical analysis or western blots. Western blots of bison tears did not reveal lysozyme.

Conclusion and Clinical Relevance—Distribution of lactoferrin and a lack of lysozyme are similar in the lacrimal gland of cattle and bison. Differences in other tear components may be responsible for variability in the susceptibility to infectious corneal diseases that exists between bison and cattle. (Am J Vet Res 2003;64:104–108)

Full access
in American Journal of Veterinary Research

SUMMARY

Contact in vivo wide-field specular microscopy was performed on right eyes of 20 healthy dogs after sodium hyaluronate (1%, n = 5), sodium chondroitin sulfate (4%) and sodium hyaluronate (3%, n = 5), hydroxypropyl methylcellulose (2%, n = 5), or balanced salt solution (control, n = 5) was injected into the anterior chamber. Using computerized morphometric analysis and pachymetry, changes in endothelial cell density, cell morphologic features, and corneal thickness from baseline values were evaluated at postinjection hour (pih) 72 and pih 168. Changes were not seen in endothelial cell density or cell morphologic features in any treated eye. The mean corneal thickness of all treated eyes at pih 72 increased 6%, significantly greater than that of the nontreated eyes (P = 0.03). Mean corneal thickness of treated and nontreated eyes was similar at baseline and pih 168 in all treatment groups.

Free access
in American Journal of Veterinary Research