Applying computer-assisted structure elucidation algorithms for the purpose of structure validation: revisiting the NMR assignments of hexacyclinol.

Computer-assisted structure elucidation (CASE) using a combination of 1D and 2D NMR data has been available for a number of years. These algorithms can be considered as "logic machines" capable of deriving all plausible structures from a set of structural constraints or "axioms", defined by the spectroscopic data and associated chemical information or prior knowledge. CASE programs allow the spectroscopist not only to determine structures from spectroscopic data but also to study the dependence of the proposed structure on changes to the set of axioms. In this article, we describe the application of the ACD/Structure Elucidator expert system to help resolve the conflict between two different hypothetical hexacyclinol structures derived by different researchers from the NMR spectra of this complex natural product. It has been shown that the combination of algorithms for both structure elucidation and structure validation delivered by the expert system enables the identification of the most probable structure as well as the associated chemical shift assignments.

Pretransport Pediatric Risk of Mortality (PRISM) score underestimates the requirement for intensive care or major interventions during interhospital transport.

OBJECTIVE: To test the hypothesis that a pretransport Pediatric Risk of Mortality (PRISM) score underestimates the requirement for both intensive care and interventions during pediatric interhospital transport. DESIGN: Prospective, descriptive study. SETTING: All children were treated in a regional hospital and then transported to a pediatric tertiary care center by a pediatric critical care specialty team. PATIENTS: Children (n = 156) with a median age of 1.3 yrs (range newborn to 18 yrs). INTERVENTIONS: None related to the study. MEASUREMENTS AND MAIN RESULTS: Two sets of Pediatric Risk of Mortality scores were calculated: one from data collected over the telephone at the time of the referral (Referral PRISM), and one from both the referring hospital's records and from data collected by the transport team on arrival at the referring hospital and before the team provided any intervention (Team PRISM). The admission area used on arrival at the tertiary care center (intensive care unit [ICU] vs. non-ICU) and the number of major clinical interventions performed by both the referring hospital staff and the transport team were recorded. The Therapeutic Intervention Scoring System was used to assess the cumulative level of medical care provided up to 8 hrs after admission to the pediatric tertiary care hospital. No patient died during transport. The overall in-hospital mortality rate was 5.1%. Median Therapeutic Intervention Scoring System scores were higher for patients admitted to the ICU (16 vs. 4, p < .001). Whereas median PRISM scores were significantly higher in those children admitted to the ICU (4 vs. 0, p < .001), 58 (75%) of 77 ICU admissions had a Team PRISM score of < or = 10. Forty-four (71%) of 62 children who required at least one major intervention at some time during the transport process and 15 (63%) of 24 children who required at least one major intervention by the transport team had a Team PRISM score of < or = 10. Referral PRISM scores underestimated Team PRISM scores. CONCLUSIONS: PRISM scores determined before interhospital transfer of pediatric patients underestimated the requirement for intensive care and the performance of major interventions in the pretransport setting. Many patients with low PRISM scores required intensive care on admission to the receiving hospital and major interventions during the transport process, and, therefore, were not at "low risk" for clinical deterioration. The PRISM score should not be used as a severity of illness measure or triage tool for pediatric interhospital transport.