Ocular Toxicity of Benzalkonium Chloride Homologs Compared with Their Mixtures

This study was performed to assess the in vivo ocular toxicity of benzalkonium chloride (BAK) homologs compared with commercially available BAK (BAK mixture) and to assess the ocular toxicity of BAK homolog after repeated ocular application. Rabbit eyes were examined by ophthalmology and scanning electron microscopy (SEM) after 10 applications of BAK homologs with C12 (C12-BAK) and C14 (C14-BAK) alkyl chain lengths and a BAK mixture at concentrations of 0.001% (w/v), 0.003% (w/v), 0.005% (w/v), 0.01% (w/v) and 0.03% (w/v). The ocular toxicity of C12-BAK to rabbit eyes was examined by ophthalmology and histopathology after repeated ocular application for 39 weeks. In addition, the antimicrobial activities of C12-BAK and C14-BAK against A. niger, S. aureus and P. aeruginosa were assessed. Ocular toxicity of C12-BAK was less than those of the BAK mixture and C14-BAK. No ocular toxicity was noted after ocular application of 0.01% C12-BAK to rabbits for 39 weeks. C12-BAK showed antimicrobial activities at a concentration of 0.003%. These results suggest that the use of C12-BAK to replace BAK mixture as a preservative in ophthalmic solutions should be considered in order to reduce the incidence of the corneal epithelial cell injury induced clinically by BAK.     

Nosological study of Borna disease virus infection in race horses.

To investigate the prevalence of diseases in the Borna disease virus (BDV) antibody positive race horses, we undertook seroepidemiological studies of BDV infection on 125 culled race horses in Hokkaido, Japan. The serological study disclosed the presence of antibodies only to BDV-p40 or -p24 in 19.2% (24/125) and 3.2% (4/125) of culled horses, respectively. Antibodies to both BDV-p40 and -p24 were found in 24.0% (30/125) of these horses. Of particular note was the finding that locomotorium disorders were detectable at a significantly higher rate in BDV antibody positive horses than that in the seronegative horses. These results imply that BDV infection may possibly contribute to an increase in the incidence rate of locomotorium disorders in race horses.     

Comparison of serum lipid compositions, lipid peroxide, alpha-tocopherol and lipoproteins in captive marine mammals (bottlenose dolphins, spotted seals and West Indian manatees) and terrestrial mammals

Concentrations of serum lipid components, lipid peroxide (LPO) and α-tocopherol and electrophoretic patterns of lipoproteins in serum samples obtained from captive marine mammals and terrestrial mammals were compared. Serum concentrations of total cholesterol, free fatty acid, and phospholipid in fish-eating animals were significantly higher than those in manatees and cows. Serum LPO and α-tocopherol concentrations in the fish-eating animals were also significantly higher than those in manatees, cows and dogs. Different patterns of densitometric scans of low density lipoprotein (LDL) and a significantly lower percentage of LDL were demonstrated in the dolphins compared with the seals, cow and dogs. The concentration of LPO was significantly correlated with triglyceride and phospholipid concentrations in serum from the dolphins. These results suggest that triglyceride and phospholipid are susceptible to oxidative reaction in fish-eating animals. Evaluation of serum lipids, LPO and α-tocopherol concentrations is needed for nutritional husbandry for fish-eating animals.