PTSD malingering detection in damage claim cases: Diagnostic accuracy in cases of personal injury as a result of motor vehicle accidents.

This study aimed to assess the accuracy of post-traumatic stress disorder (PTSD) diagnoses made by mental health experts in people reporting post-traumatic stress symptoms related to traffic accidents. Data were collected from sixty participants: 30 with possible traumatic experiences and 30 who had never experienced this or other types of traumatic events. Six professional diagnosticians examined the participants with Structured Clinical Interview for the Study of Axis I Disorders (SCID-I for DSM-IV-TR) in conditions similar to those typical of judicial cases related to traffic accident damage claims. There was no significant difference in the number of PTSD diagnoses between malingerers and non-malingerers. Some PTSD symptoms were more frequently recognized in malingerers. This study demonstrates that even professional diagnosticians with clinical and jurisprudence experience have significant difficulty identifying PTSD malingering. This difficulty can be linked to the limitations of diagnoses based on introspective reports.

Can We Execute Stable Microsecond-Scale Atomistic Simulations of Protein-RNA Complexes?

We report over 30 µs of unrestrained molecular dynamics simulations of six protein-RNA complexes in explicit solvent. We utilize the AMBER ff99bsc0χ(OL3) RNA force field combined with the ff99SB protein force field and its more recent ff12SB version with reparametrized side-chain dihedrals. The simulations show variable behavior, ranging from systems that are essentially stable to systems with progressive deviations from the experimental structure, which we could not stabilize anywhere close to the starting experimental structure. For some systems, microsecond-scale simulations are necessary to achieve stabilization after initial sizable structural perturbations. The results show that simulations of protein-RNA complexes are challenging and every system should be treated individually. The simulations are affected by numerous factors, including properties of the starting structures (the initially high force field potential energy, resolution limits, conformational averaging, crystal packing, etc.), force field imbalances, and real flexibility of the studied systems. These factors, and thus the simulation behavior, differ from system to system. The structural stability of simulated systems does not correlate with the size of buried interaction surface or experimentally determined binding affinities but reflects the type of protein-RNA recognition. Protein-RNA interfaces involving shape-specific recognition of RNA are more stable than those relying on sequence-specific RNA recognition. The differences between the protein force fields are considerably smaller than the uncertainties caused by sampling and starting structures. The ff12SB improves description of the tyrosine side-chain group, which eliminates some problems associated with tyrosine dynamics.