Search Results

You are looking at 1 - 7 of 7 items for

  • Author or Editor: B. Keith Collins x
  • Refine by Access: All Content x
Clear All Modify Search
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the effects of varios concentrations of L-lysine and L-arginine on in vitro replication of feline herpesvirus type-1 (FHV-1).

Sample Population—Cultured Crandell-Reese feline kidney (CRFK) cells and FHV-1 strain 727.

Procedure—Uninfected CRFK cells or CRFK cells infected with FHV-1 were cultured in Dulbecco's modified Eagle's medium or in 1 of 7 test media containing various concentrations of lysine and arginine. Viral titer and CRFK growth rate were assessed in each medium.

Results—Media depleted of arginine almost completely inhibited viral replication, whereas 2.5 or 5.0 µg of arginine/ml of media was associated with a significant increase in FHV-1 replication. In media with 2.5 µg of arginine/ml, supplementation with 200 or 300 µg of lysine/ml reduced viral replication by 34.2 and 53.9%, respectively. This effect was not seen in media containing 5.0 µg of arginine/ml. Growth rates of CRFK cells also were suppressed in media containing these concentrations of amino acids, but they were not significantly different from each other.

Conclusions and Clinical Relevance—Arginine exerts a substantial growth-promoting effect on FHV-1. Supplementation of viral culture medium with lysine attenuates this growth-promoting effect in media containing low concentrations of arginine. Analysis of data from this study indicates that high concentrations of lysine reduce in vitro replication of FHV-1 but only in media containing low concentrations of arginine. Clinical trials will be necessary to determine whether supplemental administration of lysine, with or without arginine restriction, will be useful in the management of cats with FHV-1 infections. (Am J Vet Res 2000; 61:1474–1478)

Full access
in American Journal of Veterinary Research

Summary

Seventy-three aerobic bacterial isolates were cultured from 64 eyes of 63 horses with infectious keratitis. Forty-two (58%) of the organisms isolated initially were gram-positive (g+, 10 genera) and 31 (42%) were gram-negative (g-, 5 genera). After local antimicrobial treatment, repeat cultures from samples obtained from 15 eyes of hospitalized horses yielded 21 secondary bacterial isolates. Staphylococci spp and Streptococci spp were the most common g(+) isolates and accounted for 79% of g(+) organisms isolated initially. Antibiograms revealed ticarcillin to be the most efficacious antibiotic tested on g(+) organisms, with 28 of 30 (93%) being susceptible. Of commercially available topical ophthalmic antibiotics tested on g(+) organisms, erythromycin was the most efficacious, with 32 of 35 (91%) isolates being susceptible. Pseudomonas spp, Escherichia coli, and Acinetobacter spp accounted for 68% of g(-) organisms isolated initially. Gentamicin, tobramycin, polymyxin B, and neomycin were highly effective in vitro against initial g(-) isolates. Chloramphenicol was ineffective against g(+) and g(-) organisms isolated initially. A significantly (P < 0.05) higher frequency of g(-) organisms was noticed on repeat cultures after intensive topical antimicrobial treatments as compared to organisms isolated at initial examination. Pseudomonas organisms isolated from second cultures were resistant to gentamicin, but susceptible to ciprofloxacin. Overall, secondary g(-) isolates were more susceptible to ciprofloxacin, neomycin, tobramycin, or amikacin than to gentamicin. Fungi were isolated in 24 of 63 (38%) horses in the study. Twenty-five filamentous fungi and 2 yeasts were identified from 24 eyes. Aspergillus spp was the predominant fungi; it was detected in 17 of 22 (77%) eyes in which filamentous fungi were identified.

Free access
in Journal of the American Veterinary Medical Association

Summary

A closely inbred line of Chow Chows affected with congenital cataracts was studied. Sixteen dogs were examined including 1 adult male, 2 adult females, and 13 pups. Twelve of the pups were from 6 different litters, out of 6 different bitches, all sired by 1 adult male. The exact relationship of the thirteenth pup was undetermined. Clinical evaluation included slit-lamp biomicroscopy, biomicroscopic photography, and indirect ophthalmoscopy. Clinical appearance of the cataracts was variable, ranging from incipient nuclear or capsular lesions to advanced cortical opacity. The lens nucleus was most consistently affected, with variable involvement of the lens cortex. Concurrent ocular anomalies of some eyes included wandering nystagmus, entropion, microphthalmia, persistent pupillary membrane remnants, and multifocal retinal folds. A correlation was not apparent between the character or severity of the cataracts and the fnding of the other anomalies. Histologic examination of 12 lenses revealed posterior displacement of the lens nucleus, retained lens epithelial cell nuclei in the nuclear and cortical lens, anterior capsular irregularity and duplication, anterior lens epithelial duplication, and posterior subcapsular migration of epithelium. The high incidence of cataract in this family of Chow Chows suggested an inherited defect, although the inheritance pattern was undetermined.

Free access
in Journal of the American Veterinary Medical Association