ESR and calculations on electronic structure of phenalenyl and phenalenyl derivative radicals.

Calculations on electronic structure of the perinaphthenyl radical and phenalenyl derivative radicals responsible for the composition of the ESR spectrum of marine diesel under heating were performed to obtain support for the experimental ESR results. The parameters calculated were the hyperfine coupling constants (A), which were then used for comparison with the experimental data. The energy-minimized structures were obtained using the density functional theory method.

Should preconditioning hyperbaric oxygenation protect the liver against ischemia-reperfusion injury? An experimental study in a rat model.

Objectives: We designed studies to test the hypotheses that hyperbaric oxygen (HBO) therapy should protect liver against subsequent ischemia/reperfusion (I/R) injury are scarce and controversial. The purpose of this study was to clarify some questions about the association of HBO with the processes of liver I/R.

Methods: We divided Wistar rats into 5 groups: (1) SHAM operation, (2) I/R, rats submitted to total pedicle ischemia for 30 minutes followed by 5 minutes of reperfusion; (3) HBO60I/R and (4) HBO120I/R, rats respectively submitted to 60 and 120 minutes of HBO therapy at 2 absolute atmospheres and immediately after submitted to the experimental protocol of I/R; (5) HBO120, rats submitted to 120 minutes of HBO therapy at 2 absolute atmospheres and then immediately after humanely killed.

Supraceliac clamping in the surgical treatment of abdominal aortic aneurysm. An experimental study in dogs.

Previous reports have suggested the use of supraceliac aortic clamping in the surgical treatment of abdominal aortic aneurysm of difficult approach. The objective of the present report was to study the hepatic and renal metabolic changes of three groups of dogs submitted to temporary clamping (30 minutes) of the abdominal aorta at three different levels: below the renal arteries, infrarenal group (8 dogs); above the renal arteries, suprarenal group (9 dogs); above the celiac artery, supraceliac group (9 dogs). Blood bilirubin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea nitrogen, and creatinine levels were measured before clamping and 5 minutes and 24 hours after reperfusion of the aorta.