Transgenic maize event TC1507: Global status of food, feed, and environmental safety.

Maize (Zea mays) is a widely cultivated cereal that has been safely consumed by humans and animals for centuries. Transgenic or genetically engineered insect-resistant and herbicide-tolerant maize, are commercially grown on a broad scale. Event TC1507 (OECD unique identifier: DAS-Ø15Ø7-1) or the Herculex®(#) I trait, an insect-resistant and herbicide-tolerant maize expressing Cry1F and PAT proteins, has been registered for commercial cultivation in the US since 2001.

Model-based tolerance intervals derived from cumulative historical composition data: application for substantial equivalence assessment of a genetically modified crop.

Compositional analysis is a requisite component of the substantial equivalence framework utilized to assess genetically modified (GM) crop safety. Statistical differences in composition data between GM and non-GM crops require a context in which to determine biological relevance. This context is provided by surveying the natural variation of key nutrient and antinutrient levels within the crop population with a history of safe use.

Barriers to assessing fitness to drive in dementia in nova scotia: informing strategies for knowledge translation.

Background And Purpose: Over half a million Canadians have a diagnosis of dementia, approximately 25-30% of whom continue to drive. Individuals with dementia have a risk of motor vehicle collision up to eight times that of drivers without dementia. In Nova Scotia, the responsibility of reporting unsafe drivers is discretionary, but national survey data indicate that many physicians do not feel comfortable assessing driving safety.

Signaling pathways: the benefits of good communication.

Recent studies show that hyperactivated mTOR, the 'target of rapamycin' that senses nutrient availability in eukaryotic cells, inhibits signaling by insulin receptor substrates. This crosstalk reveals how hyperactivated mTOR may suppress metastasis locally, while causing systemic insulin resistance that can progress to diabetes.

Upregulation of insulin receptor substrate-2 in pancreatic beta cells prevents diabetes.

The insulin receptor substrate-2 (Irs2) branch of the insulin/IGF signaling system coordinates peripheral insulin action and pancreatic beta cell function, so mice lacking Irs2 display similarities to humans with type 2 diabetes. Here we show that beta cell-specific expression of Irs2 at a low or a high level delivered a graded physiologic response that promoted beta cell growth, survival, and insulin secretion that prevented diabetes in Irs2-/- mice, obese mice, and streptozotocin-treated mice; and that upon transplantation, the transgenic islets cured diabetes more effectively than WT islets. Thus, pharmacological approaches that promote Irs2 expression in beta cells, especially specific cAMP agonists, could be rational treatments for beta cell failure and diabetes.

Molecular mechanisms of insulin resistance in IRS-2-deficient hepatocytes.

To assess the role of insulin receptor (IR) substrate (IRS)-2 in insulin action and resistance in the liver, immortalized neonatal hepatocyte cell lines have been generated from IRS-2(-/-), IRS-2(+/-), and wild-type mice. These cells maintained the expression of the differentiated liver markers albumin and carbamoyl phosphate synthetase, as well as bear a high number of IRs. The lack of IRS-2 did not result in enhanced IRS-1 tyrosine phosphorylation or IRS-1-associated phosphatidylinositol (PI) 3-kinase activity on insulin stimulation.