Micronutrient status and glutathione peroxidase in bedridden patients on tube feeding.

Deficiency of micronutrients, especially selenium, is common in critically ill patients. We investigated the micronutrient status (selenium, zinc, copper and manganese) and glutathione peroxidase (GSH-Px) activity in 30 tube-fed patients and 21 hospitalized non-tube-fed control patients. Serum levels of selenium, copper and manganese in tube-fed patients were significantly lower than in control patients (selenium: 4.85+/-1.38 microg/dl versus 8.67+/-1.45 pg/dl; copper: 44.7+/-36.9 microg/dl versus 92.1+/-21.2 microg/dl; manganese 0.59+/-0.41 microg/dl versus 1.52+/-0.59 microg/dl). However, zinc and log GSH-Px in the serum were similar in the two groups. Serum selenium concentration correlated with the daily intake of selenium in tube-fed patients, but zinc, copper and manganese concentrations did not correlate with the daily intake of the respective trace elements in tube-fed patients. Blood GSH-Px activity correlated positively with serum selenium concentrations in the control patients, but not in tube-fed patients. These results demonstrate that selenium content of enteral feed appears to be insufficient to maintain normal serum levels in elderly bedridden patients. Our findings emphasize the importance of monitoring micronutrient status in patients on enteral feeding to avoid trace element deficiencies.

Efficacy of a liposome preparation of anti-inflammatory steroid as an ocular drug-delivery system.

The efficacy of a liposome preparation on ocular steroid availability was investigated by both tracer studies and investigation of in vivo steroid uptake by the cornea. Dexamethasone and its ester derivatives were used as model drugs and aqueous suspensions of each served as control preparations. The liposome preparation containing dexamethasone valerate provided the highest ocular drug levels among the examined preparations. In the case of dexamethasone or dexamethasone palmitate, the liposomal form provided a lower drug level in comparison with the suspension. High esterase activity for dexamethasone valerate was observed in the corneal homogenate supernatant, and most of the steroid taken up after instillation of dexamethasone valerate was metabolized to free alcohol. The corneal dexamethasone level was almost proportional to the concentration of free dexamethasone valerate in the liposome preparation. Only the addition of stearylamine (SA) to the liposomal membrane had an added extra effect on the corneal absorption of dexamethasone valerate.