Smaller hippocampal volume following sexual assault in women is associated with post-traumatic stress disorder.

OBJECTIVE: Exposure to sexual assault is a significant risk factor to develop post-traumatic stress disorder (PTSD) in females. The early neurobiological changes leading to the development of PTSD remain understudied and unclear in this population. METHODS: Participants were 27 adult females recruited within a month following exposure to sexual assault (T1) and 20 age-matched non-exposed controls. Among the victims, 10 participants met (PTSD+) and 15 did not meet (PTSD-) DSM-IV criteria for PTSD 6 months post-trauma (T2). At both visits, hippocampal and amygdala volumes were extracted from magnetic resonance imaging scans, and indices of total diurnal cortisol changes were derived from individual areas under the curve relative to the ground (AUCg). Measures at T1 were compared between groups at T1, measures at T2 between groups at T2, and measures at T1 between groups at T2. RESULTS: At T1, victims had significantly smaller bilateral hippocampal volumes, but not AUCg, than controls. At T2, neither hippocampal volume nor AUCg significantly differed among the groups. However, the PTSD+ group had significantly smaller hippocampal volumes at T1 than the control group, but not compared to the PTSD- group. CONCLUSIONS: This study indicates that having smaller hippocampal volumes is a risk factor to develop PTSD in females exposed to sexual assault.

Validation of amino-acids measurement in dried blood spot by FIA-MS/MS for PKU management.

OBJECTIVES: Phenylketonuria (PKU) is a metabolic disorder leading to high concentrations of phenylalanine (Phe) and low concentrations of tyrosine (Tyr) in blood and brain that may be neurotoxic. This disease requires a regular monitoring of plasma Phe and Tyr as well as branched-chain amino-acids concentrations to adapt the Phe-restricted diet and other therapy that may be prescribed in PKU. We validated a Flow Injection Analysis tandem Mass Spectrometry (FIA-MS/MS) to replace the enzymatic method routinely used for neonatal screening in order to monitor in parallel to Phe, Tyr and branched-chain amino-acids not detected by the enzymatic method. DESIGN AND METHODS: We ascertained the performances of the method: linearity, detection and quantification limits, contamination index, accuracy. We cross validated the FIA-MS/MS and enzymatic methods and we evaluated our own reference ranges to monitor Phe, Tyr, Leu, Val on 59 dried blood spots of normal controls. We also evaluated Tyr, Leu and Val concentrations in PKU patients to detect some potential abnormalities, not evaluated by the enzymatic method. RESULTS: We developed a rapid method with excellent performances including precision and accuracy <15%. We noted an excellent correlation of Phe concentrations between FIA-MS/MS and enzymatic methods (p<0.0001) based on our database which are similar to references ranges published. We observed that 50% of PKU patients had lower concentrations of Tyr, Leu and/or Val that could not be detected by the enzymatic method. CONCLUSION: Based on laboratory accreditation recommendations, we validated a robust, rapid and reliable FIA-MS/MS method to monitor plasma Phe concentrations but also Tyr, Leu and Val concentrations, suitable for PKU management. We evaluated our own reference ranges of concentration for a routine application of this method.