Psychometric Analysis of the Visual Form Discrimination Test

The Visual Form Discrimination Test is a matching-to-sample test involving visual discrimination. Although normative information has been presented, limited psychometric data have been available. The current study estimated the internal consistency and additional psychometric properties of the test in a sample of 66 persons with acute traumatic brain injury. Internal consistency as measured by alpha was .66. A homogeneous sample and a restricted range of scores likely attenuated this estimate. Using the standard cutoff score, only 32% of the sample showed impaired performance. Visual form discrimination as measured by this test may be affected less by traumatic brain injury than other cognitive processes such as attention and memory.

Modifying chemotherapy response by targeted inhibition of eukaryotic initiation factor 4A

Translation is regulated predominantly at the initiation phase by several signal transduction pathways that are often usurped in human cancers, including the PI3K/Akt/mTOR axis. mTOR exerts unique administration over translation by regulating assembly of eukaryotic initiation factor (eIF) 4F, a heterotrimeric complex responsible for recruiting 40S ribosomes (and associated factors) to mRNA 5′ cap structures. Hence, there is much interest in targeted therapies that block eIF4F activity to assess the consequences on tumor cell growth and chemotherapy response. We report here that hippuristanol (Hipp), a translation initiation inhibitor that selectively inhibits the eIF4F RNA helicase subunit, eIF4A, resensitizes Eμ-Myc lymphomas to DNA damaging agents, including those that overexpress eIF4E—a modifier of rapamycin responsiveness. As Mcl-1 levels are significantly affected by Hipp, combining its use with the Bcl-2 family inhibitor, ABT-737, leads to a potent synergistic response in triggering cell death in mouse and human lymphoma and leukemia cells. Suppression of eIF4AI using RNA interference also synergized with ABT-737 in murine lymphomas, highlighting eIF4AI as a therapeutic target for modulating tumor cell response to chemotherapy.