The role of organic osmolytes in the response of cultured astrocytes to hyperosmolarity.

Idiogenic osmoles are volume-regulatory organic solutes that accumulate within a cell in response to hyperosmolar conditions such as those found in diabetic ketoacidosis or hypernatremic dehydration in infants. Intracellular metabolites known to play this role include certain amino acids and taurine, polyols, and trimethylamines. In this study, in vitro astrocyte cultures prepared from the cerebral cortices of 1-day-old Sprague-Dawley rats were exposed to graded conditions of hypernatremia (325-375 mOsm/kg), a range that can be observed in vivo, for 24, 48, and 72 hours.

Two-stage arterial switch operation: is late ever too late?

Results of the two-stage arterial switch operation in 49 patients with transposition of the great arteries, performed between January 1995 and September 2000, were reviewed retrospectively. Twenty-one patients had a ventricular septal defect. Anatomical correction was carried out 21.