INTRODUCTION Shock index and its pediatric adjusted derivative (pediatric age-adjusted shock index [SIPA]) have demonstrated utility as prospective predictors of mortality in adult and pediatric trauma populations. Although basic vital signs provide promise as triage tools, factors such as neurologic status on arrival have profound implications for trauma-related outcomes. Recently, the reverse shock index multiplied by Glasgow Coma Scale (GCS) score (rSIG) has been validated in adult trauma as a tool combining early markers of physiology and neurologic function to predict mortality. This study sought to compare the performance characteristics of rSIG against SIPA as a prospective predictor of mortality in pediatric war zone injuries. METHODS Retrospective review of the Department of Defense Trauma Registry, 2008 to 2016, was performed for all patients younger than 18 years with documented vital signs and GCS on initial arrival to the trauma bay. Optimal age-specific cutoff values were derived for rSIG via the Youden index using receiver operating characteristic analyses. Multivariate logistic regression was performed to validate accuracy in predicting early mortality. RESULTS A total of 2,007 pediatric patients with a median age range of 7 to 12 years, 79% male, average Injury Severity Score of 11.9, and 62.5% sustaining a penetrating injury were included in the analysis. The overall mortality was 7.1%. A total of 874 (43.5%) and 685 patients (34.1%) had elevated SIPA and pediatric rSIG scores, respectively. After adjusting for demographics, mechanism of injury, initial vital signs, and presenting laboratory values, rSIG (odds ratio, 4.054; p = 0.01) was found to be superior to SIPA (odds ratio, 2.742; p < 0.01) as an independent predictor of early mortality. CONCLUSION Reverse shock index multiplied by GCS score more accurately identifies pediatric patients at highest risk of death when compared with SIPA alone, following war zone injuries. These findings may help further refine early risk assessments for patient management and resource allocation in constrained settings. Further validation is necessary to determine applicability to the civilian population. LEVEL OF EVIDENCE Prognostic study, level IV.

Density functional theory has been applied to a series of unsubstituted planar metalloporphyrins (MPs) to elucidate how geometry and frequencies correlate with the metal-nitrogen distance, referred to as the core size. Different transition metals can invoke expansion or contraction of the porphyrin core due to electronic effects resulting from the amount of d-electron pairing as well as occupancy of the d(x(2)(-y(2))) orbital. A full vibrational analysis consisting of all in-plane and out-of-plane frequencies was carried out, and the resulting modes were plotted against core size for a linear analysis and grouped within symmetry blocks. The modes were separated according to planarity, and all modes with a large slope and best fit greater than 0.8 were considered sensitive to metal-nitrogen distances. All planar skeletal modes above 1450 cm(-1), including the pyrolle ring deformations, are found to be core-size sensitive. The most significant out-of-plane modes sensitive to core size are gamma(8) and gamma(9), which are infrared active and grouped within the A(2u) symmetry block. The present work also opens possible quantitative applications for the correlation of spectroscopic properties of MPs and heme proteins with actual structural parameters.

Background Optimizing nerve regeneration and mitigating muscle atrophy are the keys to successful outcomes in peripheral nerve damage. We investigated whether mesenchymal stem cell (MSC) therapy can improve limb function recovery in peripheral nerve damage. Materials and methods We used sciatic nerve transection/repair (SNR) and individual nerve transection/repair (INR; branches of sciatic nerve - tibial, peroneal, sural) models to study the effect of MSCs on proximal and distal peripheral nerve damages, respectively, in male Lewis rats. Syngeneic MSCs (5 × 10 6 ; passage≤6) or saline were administered locally and intravenously. Sensory/motor functions (SF/MF) of the limb were assessed. Results Rat MSCs (>90%) were CD29 + , CD90 + , CD34 − , CD31 − and multipotent. Total SF at two weeks post-SNR & INR with or without MSC therapy was ∼1.2 on a 0–3 grading scale (0 = No function; 3 = Normal); by 12 weeks it was 2.6–2.8 in all groups (n ≥ 9/group). MSCs accelerated SF onset. At eight weeks post-INR, sciatic function index (SFI), a measure of MF (0 = Normal; −100 = Nonfunctional) was −34 and −77 in MSC and vehicle groups, respectively (n ≥ 9); post-SNR it was −72 and −92 in MSC and vehicle groups, respectively. Long-term MF (24 weeks) was apparent in MSC treated INR (SFI -63) but not in SNR (SFI -100). Gastrocnemius muscle atrophy was significantly reduced (P < 0.05) in INR. Nerve histomorphometry revealed reduced axonal area (P < 0.01) but no difference in myelination (P > 0.05) in MSC treated INR compared to the naive contralateral nerve. Conclusion MSC therapy in peripheral nerve damage appears to improve nerve regeneration, mitigate flexion-contractures, and promote limb functional recovery.