The Efficacy of Vitamin C in the Prevention of Complex Regional Pain Syndrome After Distal Radius Fractures: A Synthesis.

The current recommendation is to use daily doses of vitamin C to prevent the occurrence of the complex regional pain syndrome (CRPS) following a distal radius fracture. The study is a synthesis of the four primary studies that examine this issue. These studies have been previously examined in the meta-analysis literature. The incidence of CRPS is lower in patients treated with the vitamin C protocol compared with the control. The significance of the difference varies from P = .02 to P = .13. Our analysis points to the fact that the relative efficacy of vitamin C has decreased over the past 15 years (P < .001). In 2014, the incidence of CRPS in the vitamin C cohort is not statistically different from the incidence in the control group (P = .76). Vitamin C has lost its relative efficacy.

Structural constraints on the three-dimensional geometry of simple viruses: case studies of a new predictive tool.

Understanding the fundamental principles of virus architecture is one of the most important challenges in biology and medicine. Crick and Watson were the first to propose that viruses exhibit symmetry in the organization of their protein containers for reasons of genetic economy. Based on this, Caspar and Klug introduced quasi-equivalence theory to predict the relative locations of the coat proteins within these containers and classified virus structure in terms of T-numbers. Here it is shown that quasi-equivalence is part of a wider set of structural constraints on virus structure. These constraints can be formulated using an extension of the underlying symmetry group and this is demonstrated with a number of case studies. This new concept in virus biology provides for the first time predictive information on the structural constraints on coat protein and genome topography, and reveals a previously unrecognized structural interdependence of the shapes and sizes of different viral components. It opens up the possibility of distinguishing the structures of different viruses with the same T-number, suggesting a refined viral structure classification scheme. It can moreover be used as a basis for models of virus function, e.g. to characterize the start and end configurations of a structural transition important for infection.

Altering the energy landscape of virus self-assembly to generate kinetically trapped nanoparticles.

Controlling self-assembly is critical to the advancement of nanotechnology. A rugged or crenated assembly energy surface can redirect assembly off path. By using a defined starting point and an energy surface made rough by a strong association energy, we can impose entirely new assembly paths and products. Normally, the coat protein (CP) of the Cowpea Chlorotic Mottle Virus (CCMV) assembles into virus-like 28 nm diameter icosahedral particles. Here we have started with the coat protein trapped in a rod-like structure in complex with DNA. When these 17 nm diameter rods are placed under the same condition, low pH, that normally leads to assembly of 28 nm diameter particles, we instead obtain 17 nm capsids. The extrusion of all-pentamer capsids from the hexagonal lattice of the rod demonstrates the importance of the starting state for controlled assembly.