Effects of ethnicity on deceased organ donation in a minority-majority state.

OBJECTIVE: To define how ethnicity affects donation rates in New Mexico when compared with the United States. We hypothesized that deceased donation rates in New Mexico would reflect the ethnic rates of the population. DESIGN: We performed a retrospective review of the Organ Procurement Database for New Mexico from 2009 to June 2012. METHODS: Rates for donors and transplant candidates were calculated relative to 2010 census population estimates by ethnicity for non-Hispanic Whites, Hispanics, and American Indians. Poisson regression analyses were used to test whether United States and New Mexico rates differed. Rates were scaled to 100,000 patient-years for reporting. SETTING: State of New Mexico population compared to United States population. SUBJECTS: Reported deaths to New Mexico Donor Services and United Network for Organ Sharing from 2009 to 2012. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Non-Hispanic White age-adjusted donor rates per 100,000 patient-years were 2.58 in New Mexico versus 2.60 in the United States, Hispanic donor rates were 1.98 in New Mexico versus 2.03 nationwide, and American Indian donor rates in New Mexico were 0.26 versus 1.23 nationwide (rate ratio = 0.21; 95% CI, 0.05-0.86). American Indians have significantly lower donor rates in New Mexico compared to non-Hispanic Whites (rate ratio = 0.11) and Hispanics (rate ratio = 0.13) and nationally (non-Hispanic Whites: rate ratio = 0.32 and Hispanics: rate ratio = 0.43). Hispanics and non-Hispanic Whites had similar donor rates regardless of geographic strata (Hispanics vs non-Hispanic Whites, New Mexico: 0.83; United States: 0.75). In New Mexico, Hispanic patients were 1.43 times more likely to be listed as transplant candidates than non-Hispanic Whites and American Indians were 3.32 times more likely to be listed than non-Hispanic Whites. In the United States, Hispanic patients were 1.90 times more likely to be listed as transplant candidates than non-Hispanic Whites and American Indians were 1.55 times more likely to be listed than non-Hispanic Whites. CONCLUSIONS: Donor and transplant candidate rates did not show strong differences by geographic strata. These findings suggest that further work is needed to elucidate the causes for ethnic differences in rates of consent and donation, particularly in the American Indian population.

Family presence during brain death evaluation: a randomized controlled trial*.

OBJECTIVE: To evaluate if a family presence educational intervention during brain death evaluation improves understanding of brain death without affecting psychological distress. DESIGN: Randomized controlled trial. SETTING: Four ICUs at an academic tertiary care center. SUBJECTS: Immediate family members of patients suspected to have suffered brain death. INTERVENTIONS: Subjects were group randomized to presence or absence at bedside throughout the brain death evaluation with a trained chaperone. All randomized subjects were administered a validated "understanding brain death" survey before and after the intervention. Subjects were assessed for psychological well-being between 30 and 90 days after the intervention. MEASUREMENTS AND MAIN RESULTS: Follow-up assessment of psychological well-being was performed using the Impact of Event Scale and General Health Questionnaire. Brain death understanding, Impact of Event Scale, and General Health Questionnaire scores were analyzed using Wilcoxon nonparametric tests. Analyses were adjusted for within family correlation. Fifty-eight family members of 17 patients undergoing brain death evaluation were enrolled: 38 family members were present for 11 brain death evaluations and 20 family members were absent for six brain death evaluations. Baseline understanding scores were similar between groups (median 3.0 [presence group] vs 2.5 [control], p = 0.482). Scores increased by a median of 2 (interquartile range, 1-2) if present versus 0 (interquartile range, 0-0) if absent (p < 0.001). Sixty-six percent of those in the intervention group achieved perfect postintervention "understanding" scores, compared with 20% of subjects who were not present (p = 0.02). Median Impact of Event Scale and General Health Questionnaire scores were similar between groups at follow-up (Impact of Event Scale: present = 20.5, absent = 23.5, p = 0.211; General Health Questionnaire: present = 13.5, absent = 13.0, p = 0.250). CONCLUSIONS: Family presence during brain death evaluation improves understanding of brain death with no apparent adverse impact on psychological well-being. Family presence during brain death evaluation is feasible and safe.

A comparative genome analysis identifies distinct sorting pathways in gram-positive bacteria.

Surface proteins in gram-positive bacteria are frequently required for virulence, and many are attached to the cell wall by sortase enzymes. Bacteria frequently encode more than one sortase enzyme and an even larger number of potential sortase substrates that possess an LPXTG-type cell wall sorting signal. In order to elucidate the sorting pathways present in gram-positive bacteria, we performed a comparative analysis of 72 sequenced microbial genomes. We show that sortase enzymes can be partitioned into five distinct subfamilies based upon their primary sequences and that most of their substrates can be predicted by making a few conservative assumptions. Most bacteria encode sortases from two or more subfamilies, which are predicted to function nonredundantly in sorting proteins to the cell surface. Only approximately 20% of sortase-related proteins are most closely related to the well-characterized Staphylococcus aureus SrtA protein, but nonetheless, these proteins are responsible for anchoring the majority of surface proteins in gram-positive bacteria. In contrast, most sortase-like proteins are predicted to play a more specialized role, with each anchoring far fewer proteins that contain unusual sequence motifs. The functional sortase-substrate linkage predictions are available online (http://www.doe-mbi.ucla.edu/Services/Sortase/) in a searchable database.

Solution structure of the coiled-coil trimerization domain from lung surfactant protein D.

Surfactant protein D (SP-D) is one of four known protein components of the pulmonary surfactant lining the lung alveoli. It is involved in immune and allergic responses. SP-D occurs as a tetramer of trimers. Trimerization is thought to be initiated by a coiled coil domain. We have determined the solution structure of a 64-residue peptide encompassing the coiled coil domain of human SP-D. As predicted, the domain forms a triple-helical parallel coiled coil. As with all symmetric oligomers, the structure calculation was complicated by the symmetry degeneracy in the NMR spectra. We used the symmetry-ADR (ambiguous distance restraint) structure calculation method to solve the structure. The results demonstrate that the leucine zipper region of SP-D is an autonomously folded domain. The structure is very similar to the independently determined X-ray crystal structure, differing mainly at a single residue, Tyr248. This residue is completely symmetric in the solution structure, and markedly asymmetric in the crystalline phase. This difference may be functionally important, as it affects the orientation of the antigenic surface presented by SP-D.