The corneal epithelium after optisol-GS storage.

The objective of this study was to evaluate the epithelium of human corneas stored in Optisol-GS (Chiron Intraoptics, Irvine, CA) for extended periods (2-34 days). Human corneas stored in Optisol-GS (n = 64) were obtained from the Georgia Eye Bank. Corneal epithelial viability was assessed by using the Calcein-AM (Molecular Probes, Inc., Eugene, OR) ethidium homodimer stain, a fluorescent assay used to distinguish live from dead cells. Scanning and transmission electron microscopy was used to evaluate epithelial ultrastructure. The results showed that corneas stored up to 6 days in Optisol-GS had minimal damage of the epithelium. Calcein-AM ethidium homodimer staining showed 20-25% epithelial damage. Corneas stored 7-10 days had a further increase in epithelial damage (30-35%). Corneas stored for 11-15 days had marked increases in epithelial damage (40-50%), and corneas stored 16-34 days showed significant epithelial damage (60-70%). The data show that corneas stored in Optisol-GS are able to maintain the epithelium up to 6 days. A gradual decrease in epithelial viability and loss of epithelial cells occurs in corneas stored 6-10 days. Corneas stored for > 10 days have a marked loss of epithelial cells with extensive epithelial damage.

Viability of human corneal endothelium following Optisol-GS storage.

OBJECTIVES: To evaluate endothelial viability of human corneas stored in glass vials and in viewing chambers (Alcon) for extended periods, and to compare endothelial viability of Optisol-GS-stored corneas with corneas excised from moist chamber-stored globes. METHODS: Endothelial viability was assessed using two staining techniques. Endothelium from stored corneas was stained with trypan blue combined with alizarin red S or stained with calcein AM-ethidium homodimer. Both techniques were used to determine which method is a more sensitive indicator of cytotoxic change. RESULTS: Corneas stored 4 to 21 days in Optisol-GS had a rate (mean +/- SE) of endothelial cell damage of 0.57% +/- 0.30% per day in vials and 0.69% +/- 0.27% in chambers. After storage intervals from 4 to 21 days, the Optisol-GS endothelium had an average decrease in viability of 9.5% to 16%. The endothelium of moist chamber eyes had a 44% to 59% decrease in viability after 2 to 5 days. After 24 hours, corneal endothelium of moist chamber eyes had less than 15% decrease in viability. Optisol-GS corneas stored for 35 to 56 days had greater than 50% decrease in endothelial viability. After 67 days, 95% to 100% of endothelial viability was lost. CONCLUSIONS: Corneas stored in Optisol-GS through 21 days at 4 degrees C maintain a high percentage of viable endothelial cells. There was no significant difference of endothelial viability between corneas stored in glass vials or in viewing chambers (Alcon). A 50% loss of endothelial viability occurred in moist chamber-stored corneas after 2 days and by 35 days in corneas stored in Optisol-GS.

Renal failure attributable to atrophic glomerulopathy in four related rottweilers.

Atrophic glomerulopathy resulting in chronic renal failure was diagnosed in 4 related Rottweilers, each < 1 year old. All 4 dogs had severe azotemia and massive protein-losing nephropathy. Histologically, the glomerular lesion was characterized by mild dilatation of Bowman's space, with glomerular tufts absent or markedly atrophied. The lesion is distinct from the congenital glomerular changes described in Samoyeds or Doberman Pinschers.

Intraluminal prostaglandin stimulation and bile salt inhibition of basal acid secretion in the instilled rat stomach.

To determine the effect of prostaglandin on acid secretion and the effectiveness of cytoprotection afforded by prostaglandins against bile salt damage, the stomachs of anesthetized rats were exteriorized and cannulated for determination of net acid output (H+) and electrical potential difference (PD). The stomachs were successively instilled with acid buffer, 5 mM and 15 mM sodium taurocholate (NaTC) with or without 3.3 X 10-6M 16, 16-dimethyl prostaglandin E2 (dmPGE2). With dmPGE2 present in the instillate, H+ was twice as large in the control period. Exposure to 5mM NaTC reduced H+ by 63% and abolished the stimulatory effect of dmPGE2. Subsequent exposure to 15mM NaTC depressed H+ further. In the absence of dmPGE2, NaTC reduced H+ to equivalent rates. The PD was unaffected by NaTC in the presence of dmPGE2 and lowered by 45% in the absence of dmPGE2. It may be concluded that 1) prostaglandins stimulate rather than inhibit basal H+ in vivo, and 2) prostaglandins provide weak protection against the ionic actions of conjugated bile salts instilled in the stomach.