Management of patients with a failed kidney transplant: Dialysis reinitiation, immunosuppression weaning, and transplantectomy

The number of patients reinitiating dialysis after a failed transplant increases over time and has more than doubled between the year 1988 and 2010 （an increase from 2463 to 5588）. More importantly, patients returning to dialysis have been shown to have a greater thanthree-fold increase in the annual adjusted mortality rates compared with those with a functioning graft. Continuation of immunosuppression to preserve residual graft function has been implicated to be a contributing factor, seemingly due to immunosuppression-ass-ociated cardiovascular and infectious complications and malignancy risk, among others. Nonetheless, maintenance low-dose immunosuppression has been suggested to confer survival beneft in patients returning to peritoneal dialysis. Whether early vs late reinitiation of dialysis or whether transplantectomy has an impact on patient survival remains poorly defined. Consensus guidelines for the management of a failed allograft are lacking. In this article, we present a literature overview on the ideal timing of dialysis reinitiation after graft loss, the management of immunosuppression after graft failure, and the risks and benefits of transplantectomy. The authors’ perspectives on the management of this special patient population are also discussed.

N-terminal truncated RHT-1 proteins generated by translational reinitiation cause semi-dwarfing of wheat Green Revolution alleles

The unprecedented wheat yield increases during the Green Revolution were achieved through the introduc-tion of the Reduced height(Rht)-B1b and Rht-D1b semi-dwarfing alleles.These Rht-1 alleles encode growth-repressing DELLA genes containing a stop codon within their open reading frame that confers gibberellin(GA)-insensitive semi-dwarfism.In this study,we successfully took the hurdle of detecting wild-type RHT-1 proteins in different wheat organs and confirmed their degradation in response to GAs.We further demonstrated that Rht-B1b and Rht-D1b produce N-terminal truncated proteins through trans-lational reinitiation.Expression of these N-terminal truncated proteins in transgenic lines and in Rht-D1c,an allele containing multiple Rht-D1b copies,demonstrated their ability to cause strong dwarfism,resulting from their insensitivity to GA-mediated degradation.N-terminal truncated proteins were detected in spikes and nodes,but not in the aleurone layers.Since Rht-B 1b and Rht-D1b alleles cause dwarfism but have wild-type dormancy,this finding suggests that tissue-specific differences in translational reinitiation may explain why the Rht-1 alleles reduce plant height without affecting dormancy.Taken together,our findings not only reveal the molecular mechanism underlying the Green Revolution but also demonstrate that trans-lational reinitiation in the main open reading frame occurs in plants.

A volume-amending method to improve mass conservation of level set approach for incompressible two-phase flows

A volume-amending method is developed both to keep the level set function as an algebraic distance function and to preserve the bubble mass in a level set approach for incompressible two-phase flows with the significantly deformed free interface. After the traditional reinitialization procedure, a vol-ume-amending method is added for correcting the position of the interface according to mass loss/gain error until the mass error falls in the allowable range designated in advance. The level set approach with this volume-amending method incorporated has been validated by three test cases: the motion of a single axisymmetrical bubble or drop in liquid, the motion of a two-dimensional water drop falling through the air into a water pool, and the interactional motion of two buoyancy-driven three- dimensional deformable bubbles. The computational results with this volume-amending method in-corporated are in good agreement with the reported experimental data and the mass is well preserved in all cases.

An Interface-Fitted Finite Element Level Set Method with Application to Solidification and Solvation

A new finite element level set method is developed to simulate the interface motion.The normal velocity of the moving interface can depend on both the local geometry,such as the curvature,and the external force such as that due to the flux from both sides of the interface of a material whose concentration is governed by a diffusion equation.The key idea of the method is to use an interface-fitted finite element mesh.Such an approximation of the interface allows an accurate calculation of the solution to the diffusion equation.The interface-fitted mesh is constructed from a base mesh,a uniform finite element mesh,at each time step to explicitly locate the interface and separate regions defined by the interface.Several new level set techniques are developed in the framework of finite element methods.These include a simple finite element method for approximating the curvature,a new method for the extension of normal velocity,and a finite element least-squares method for the reinitialization of level set functions.Application of the method to the classical solidification problem captures the dendrites.The method is also applied to the molecular solvation to determine optimal solute-solvent interfaces of solvation systems.