Insulin Increases Ceramide Synthesis in Skeletal Muscle

Aims. The purpose of this study was to determine the effect of insulin on ceramide metabolism in skeletal muscle. Methods. Skeletal muscle cells were treated with insulin with or without palmitate for various time periods. Lipids (ceramides and TAG) were isolated and gene expression of multiple biosynthetic enzymes were quantified. Additionally, adult male mice received daily insulin injections for 14 days, followed by muscle ceramide analysis. Results. In muscle cells, insulin elicited an increase in ceramides comparable to palmitate alone. This is likely partly due to an insulin-induced increase in expression of multiple enzymes, particularly SPT2, which, when knocked down, prevented the increase in ceramides. In mice, 14 days of insulin injection resulted in increased soleus ceramides, but not TAG. However, insulin injections did significantly increase hepatic TAG compared with vehicle-injected animals. Conclusions. This study suggests that insulin elicits an anabolic effect on sphingolipid metabolism in skeletal muscle, resulting in increased ceramide accumulation. These findings reveal a potential mechanism of the deleterious consequences of the hyperinsulinemia that accompanies insulin resistance and suggest a possible novel therapeutic target to mitigate its effects

Assessment of impoundment and forfeiture laws for drivers convicted of DUI. Phase II report: evaluation of Oregon and Washington Vehicle Plate Zebra Sticker Laws. Final report.

National Highway Traffic Safety Administration, Washington, D.C.Mode of access: Internet.Author corporate affiliation: National Public Services Research Institute, Landover, Md.Report covers the period 12/89 - 4/94Subject code: DYISubject code: JLKSubject code: RCCDDSubject code: RPSubject code: RRCSubject code: WW

Multiscale/cohesive zone model for composite laminate impact damage

Interface damage mechanics, or cohesive zone models, have been developed over the last decade as a method of modeling crack growth in a material or debonding between two different materials. These methods have alleviated many of the numerical problems inherent in crack modeling, including the large length scale difference between crack fronts and crack areas, strem singularities, and the adaptation of crack propagation criteria to non-linear materials. Cohesive zone models can also predict crack initiation at any number of predetermined possible crack locations. However, researchers have also found that numerical instabilities in the solutions emerge if the finite element mesh is too coarse relative to the crack process radius. Consequently, these have been practical only for very small structures, on the order of tens of millimeters, without the use of supercomputers. We will show that changing the order of numerical integration of the interface properties independently from their spatial discretization solves this convergence problem and in most cases decreases the total computation time, allowing for simulations of much larger structures. We will also show how these results are incorporated into our multilength scale model for predicting impact damage in laminated composite plates