A B S T R A C T The role of high serum and tissue levels of unconjugated bilirubin in the pathogenesis of the impaired urinary concentrating ability was investigated in homozygous (fi) Gunn rats with the congenital absence of hepatic glucuronyl transferase. Continuous phototherapy with blue fluorescent lights at a wave length of 460 nm or oral cholestyramine feeding or both reduced serum levels of unconjugated bilirubin to levels consistently below 3.0 mg/100 ml for several weeks in both weanling and adult fi Gunn rats. The renal concentrating defect was already present in weanling jj Gunn rats by 21 days of age. In treated weanling jj animals, maximum concentrating ability and the concentration of urea and nonurea solutes in the papilla and medulla, determined after 24 h of fluid deprivation, were normal when compared to unaffected heterozygous (Jj) littermates. Solute-free water reabsorption which is reduced in jaundiced fi Gunn rats was restored to normal in treated weanling ji rats. The tissue concentration of unconjugated bilirubin was reduced throughout the papilla and inner and outer medulla in the treated jj rats in comparison with untreated jj littermates. The defect in urinary concentrating ability was only partially reversible and sometimes irreversible in adult ji rats, probably because of permanent renal parenchymal damage occurring secondary to massive crystalline deposits in the papilla and medulla.

Bacterial conjunctivitis appears to resolve more rapidly when treated with appropriate topical antimicrobial agents. In this multicenter, randomized, double-blind study of efficacy and safety, patients with presumed bacterial external eye infections were assigned to topical therapy with 0.3% norfloxacin or 0.3% tobramycin. A total of 120 patients were enrolled. Of the total, 65 had documented bacterial infections and were evaluable; 59 of these patients had bacterial conjunctivitis. All of the patients with documented infections were cured or improved regardless of the drug treatment regimen or in vitro susceptibility testing results. The most common bacteria isolated were Haemophilus influenzae, Streptococcus pneumoniae, alpha-hemolytic streptococci, Staphylococcus aureus, and Staphylococcus sp. No patients had serious adverse reactions attributed to their therapy. Norfloxacin ophthalmic solution seems to be a safe, effective, and appropriate agent for the treatment of bacterial external eye infections.