Salivary Cortisol Dynamics After Mild Traumatic Brain Injury.

OBJECTIVE: To assess mild traumatic brain injury (mTBI)-related alterations in baseline (resting) salivary cortisol and cortisol reactivity to cognitive and exercise stressors, which are frequently encountered during mTBI rehabilitation and recovery. SETTING: Persons with mTBI were recruited from a level 1 trauma center emergency department. Uninjured controls (UCs) were recruited from the community. PARTICIPANTS: Participants were 37 individuals with mTBI and 24 UCs. All patients with mTBI were enrolled at 7 ± 3 days post-injury, met the American Congress of Rehabilitation Medicine definition of mTBI, and had no acute intracranial findings on clinical neuroimaging (if performed). DESIGN: A prospective cohort study design was used. All participants provided saliva samples 10 times during each of 2 visits spaced 3 weeks apart (1 week and 1 month post-injury for the mTBI group). Each visit included baseline saliva sampling and sampling to evaluate reactivity to a cognitive stressor (Paced Auditory Serial Addition Test) and physical stressor (Buffalo Concussion Treadmill Test [BCTT]). MAIN OUTCOME MEASURE: Natural log-transformed salivary cortisol was measured by enzyme immunoassay. Cortisol was predicted using a linear mixed-effects model by group (mTBI and UC), visit (1 week and 1 month), and saliva sample. RESULTS: Mean salivary cortisol was higher in the mTBI group (1.67 nmol/L [95% CI 1.42-1.72]) than in controls (1.30 nmol/L [1.12-1.47]), without an mTBI × time interaction. At 1 week, the mTBI group had greater cortisol reactivity in response to the BCTT. CONCLUSIONS: Higher cortisol in individuals with mTBI at 1 week and 1 month post-injury extends previous findings into the subacute recovery period. Furthermore, the mTBI group demonstrated a greater cortisol response to mild-to-moderate aerobic exercise (BCTT) at 1 week post-injury. Given the increasing role of exercise in mTBI rehabilitation, further research is warranted to replicate these findings and identify the clinical implications, if any, of enhanced hypothalamic-pituitary-adrenal axis responses to exercise in civilians with recent mTBI.

Algorithmic Analysis of Cahn-Ingold-Prelog Rules of Stereochemistry: Proposals for Revised Rules and a Guide for Machine Implementation.

The most recent version of the Cahn-Ingold-Prelog rules for the determination of stereodescriptors as described in Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013 (the "Blue Book"; Favre and Powell. Royal Society of Chemistry, 2014; http://dx.doi.org/10.1039/9781849733069 ) were analyzed by an international team of cheminformatics software developers. Algorithms for machine implementation were designed, tested, and cross-validated. Deficiencies in Sequence Rules 1b and 2 were found, and proposed language for their modification is presented. A concise definition of an additional rule ("Rule 6", below) is proposed, which succinctly covers several cases only tangentially mentioned in the 2013 recommendations. Each rule is discussed from the perspective of machine implementation. The four resultant implementations are supported by a 300-compound validation suite in both 2D and 3D structure data file (SDF) format as well as SMILES ( https://cipvalidationsuite.github.io/ValidationSuite ). The validation suites include all significant examples in Chapter 9 of the Blue Book, as well as several additional structures that highlight more complex aspects of the rules not addressed or not clearly analyzed in that work. These additional structures support a case for the need for modifications to the Sequence Rules.