Constant turnover of arachidonic acid and inhibition of a potassium current in Aplysia giant neurons

Steady-state currents at hyperpolarized membrane potentials were studied in the homologous giant neurons, LP1 and R2, of Aplysia using two-electrode voltage clamp. Nearly half of the steady-state current at voltages more hyperpolarized than −70 mV had characteristics similar to the inwardly rectifying potassium current ( I R ) described previously in Aplysia neurons. The pharmacological agents 4-bromophenacylbromide, indomethacin, and the phorbol ester, 12-O-tetradecanoyl-phorbol-13-acetate were found to modulate I R . I R was stimulated with BPB and indomethacin and inhibited with TPA. These agents altered I R by a mechanism independent of c AMP, which can also modulate I R . The effects of these modulators are consistent with their actions on arachidonic acid (AA) metabolism in Aplysia nervous system, suggesting AA may constitutively inhibit I R . When ganglia were perfused for 12 hr with medium containing BSA to absorb extracellular fatty acids, I R was increased nearly twofold. This increase was partially inhibited by addition of AA to the perfusion medium, and completely inhibited by pretreatment of ganglia with BPB. Although no direct effect of shortterm exposure to exogenous AA was observed, long term exposure to exogenous AA and several other unsaturated fatty acids was accompanied by a decrease in I R .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/48022/1/232_2005_Article_BF01868465.pd

Semuloparin for prevention of venous thromboembolism after major orthopedic surgery: Results from three randomized clinical trials, SAVE-HIP1, SAVE-HIP2 and SAVE-KNEE

Background: Semuloparin is a novel ultra-low-molecular-weight heparin under development for venous thromboembolism (VTE) prevention in patients at increased risk, such as surgical and cancer patients. Objectives: Three Phase III studies compared semuloparin and enoxaparin after major orthopedic surgery: elective knee replacement (SAVE-KNEE), elective hip replacement (SAVE-HIP1) and hip fracture surgery (SAVE-HIP2). Patients/Methods: All studies were multinational, randomized and double-blind. Semuloparin and enoxaparin were administered for 7-10days after surgery. Mandatory bilateral venography was to be performed between days 7 and 11. The primary efficacy endpoint was a composite of any deep vein thrombosis, non-fatal pulmonary embolism or all-cause death. Safety outcomes included major bleeding, clinically relevant non-major (CRNM) bleeding, and any clinically relevant bleeding (major bleeding plus CRNM). Results: In total, 1150, 2326 and 1003 patients were randomized in SAVE-KNEE, SAVE-HIP1 and SAVE-HIP2, respectively. In all studies, the incidences of the primary efficacy endpoint were numerically lower in the semuloparin group vs. the enoxaparin group, but the difference was statistically significant only in SAVE-HIP1. In SAVE-HIP1, clinically relevant bleeding and major bleeding were significantly lower in the semuloparin vs. the enoxaparin group. In SAVE-KNEE and SAVE-HIP2, clinically relevant bleeding tended to be higher in the semuloparin group, but rates of major bleeding were similar in the two groups. Other safety parameters were generally similar between treatment groups. Conclusions: Semuloparin was superior to enoxaparin for VTE prevention after hip replacement surgery, but failed to demonstrate superiority after knee replacement surgery and hip fracture surgery. Semuloparin and enoxaparin exhibited generally similar safety profiles. \ua9 2012 International Society on Thrombosis and Haemostasis