ABSTRACT
INTRODUCTION: Type III endoleaks are a rare but potentially life-threatening complication post endovascular aortic aneurysm repair (EVAR). CASE REPORT: A 91-year-old Chinese female, presented to our accident and emergency department for severe back and abdominal pain. She had previously undergone an EVAR procedure twenty years ago for a 6.5 cm diameter infra-renal abdominal aortic aneurysm. A CT aortogram revealed a type III endoleak, with the contralateral limb found to be disconnected from the main graft body. She was successfully treated by relining the graft using an endovascular technique. DISCUSSION: The case highlights the need for life-long stent-graft surveillance. We discuss early generation stent-grafts, type III endoleak treatment options and the current long-term data for late EVAR-related complications. CONCLUSION: For patients who had undergone EVAR, type III endoleaks can present only decades later and pose a significant risk of aneurysmal rupture.
ABSTRACT
We show that the combined action of parametric gain and Raman scattering can lead to the complete suppression of an input optical signal in a single-pump parametric amplifier. This suppression is due to an interference between the two parametric gain modes. The interference occurs only at a set of discrete combinations of pump power, phase mismatch, and frequency detuning. Experimentally we are able to demonstrate over 95% (13 dB) suppression of an input signal in an amplifier with a peak parametric gain of only 6 dB.
ABSTRACT
Two major families of transcription factors (TFs), basic helix-loop-helix (bHLH) and homeodomain (HD), are known to be involved in cell fate identity. Some recent findings suggest that these TFs are used combinatorially to code for cellular determination in the retina. However, neither the extent nor the efficiency of such a combinatorial coding mechanism has been tested. To look systematically for interactions between these two TF types that would address these questions, we used a matrix analysis. We co-expressed each of six retinally expressed bHLH TFs (XNeuroD; XNgnr-1; Xath3; Xath5; Xash1; Xash3) with each of eight retinally expressed HD TFs (XRx1; XOptx2; XSix3; XPax6; XOtx2; XOtx5b; XBH; XChx10) in retinal progenitors of Xenopus laevis using targeted lipofection. The effects of each of these combinations were assayed on the six major cell types in the retina: Retinal ganglion cells (GCs), Amacrines (ACs), Bipolars (BCs), Horizontals (HCs), Photoreceptors (PRs), and Muller cells (MCs), creating 288 result categories. Multiple-way ANOVA indicated that in 14 categories, there were interactions between the two TFs that produced significantly more or less of a particular cell type than either of the components alone. However, even the most effective combinations were incapable of generating more than 65% of any particular cell type. We therefore used the same techniques to misexpress selected combinations of three TFs in retinal progenitors, but found no further enhancements of particular cell fates, indicating that other factors are probably involved in cell type specification. To test whether particular combinations were essential for horizontal fates, we made VP16 and EnR fusion constructs of some of the factors to provide dominant negative transcriptional activities. Our results confirmed that normal activities of certain combinations were sufficient, and that individually these activities were important for this fate.
