Age-based normative data for a computerized dynamic posturography system that uses a virtual visual surround environment.

Background: Computerized dynamic posturography (CDP) is the gold standard to differentiate between sensory, motor, and central adaptive impairments to postural control.

Objective: To obtain normative values in healthy adults age 20-69 for a CDP system that uses a full-field dynamic visual surround. This is in contrast to the mechanically movable visual surround used in traditional CDP systems.

A requirement for wild-type Ras isoforms in mutant KRas-driven signalling and transformation.

The mutant forms of KRas, NRas and HRas drive the initiation and progression of a number of human cancers, but less is known about the role of WT (wild-type) Ras alleles and isoforms in cancer. We used zinc-finger nucleases targeting HRas and NRas to modify both alleles of these genes in the mutant KRas-driven Hec1A endometrial cancer cell line, which normally expresses WT copies of these genes. The disruption of either WT isoform of Ras compromised growth-factor-dependent signalling through the ERK (extracellular-signal-regulated kinase) pathway.

Identification of mutant K-Ras-dependent phenotypes using a panel of isogenic cell lines.

To assess the consequences of endogenous mutant K-Ras, we analyzed the signaling and biological properties of a small panel of isogenic cell lines. These include the cancer cell lines DLD1, HCT116, and Hec1A, in which either the WT or mutant K-ras allele has been disrupted, and SW48 colorectal cancer cells and human mammary epithelial cells in which a single copy of mutant K-ras was introduced at its endogenous genomic locus. We find that single copy mutant K-Ras causes surprisingly modest activation of downstream signaling to ERK and Akt.