Center Volume and Survival Relationship for Neonates With Congenital Diaphragmatic Hernia Treated With Extracorporeal Life Support.

OBJECTIVES: Literature is emerging regarding the role of center volume as an independent variable contributing to improved outcomes. A higher volume of index procedures may be associated with decreased morbidity and mortality. This association has not been examined for the subgroup of infants with congenital diaphragmatic hernia (CDH) receiving extracorporeal life support (ECLS). Our study aims to examine the risk-adjusted association between center volume and outcomes in CDH-ECLS neonates, hypothesizing that higher center volume confers a survival advantage. DESIGN: Multicenter, retrospective comparative study using the Extracorporeal Life Support Organization database. SETTING: One hundred twenty international pediatric centers. PATIENTS: Neonates with CDH managed with ECLS from 2000 to 2019. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The cohort included 4,985 neonates with a mortality rate of 50.6%. For the 120 centers studied, mean center volume was 42.4 ± 34.6 CDH ECLS cases over the 20-year study period. In an adjusted model, higher ECLS volume was associated with lower odds of mortality: odds ratio (OR) 0.995 (95% CI, 0.992-0.999; p = 0.014). For an increase in one sd in volume, that is, 1.75 cases annually, the OR for mortality was lower by 16.7%. Volume was examined as a categorical exposure variable where low-volume centers (fewer than 2 cases/yr) were associated with 54% higher odds of mortality (OR, 1.54; 95% CI, 1.03-2.29) compared with high-volume centers. On-ECLS complications (mechanical, neurologic, cardiac, hematologic metabolic, and renal) were not associated with volume. The likelihood of infectious complications was higher for low- (OR, 1.90; 95% CI, 1.06-3.40) and medium-volume (OR, 1.87; 95% CI, 1.03-3.39) compared with high-volume centers. CONCLUSIONS: In this study, a survival advantage directly proportional to center volume was observed for CDH patients managed with ECLS. There was no significant difference in most complication rates. Future studies should aim to identify factors contributing to the higher mortality and morbidity observed at low-volume centers.

Racism, shame, and stress reactivity among young black women.

Black women experience disproportional rates of cardiovascular disease (CVD) warranting further exploration of CVD risk factors. Growing evidence suggests acute stress reactivity studies may elucidate the mechanisms driving psychosocial correlates of CVD risks. Race-related stress has been identified as a CVD risk factor among Black women though recent evidence suggests emotions may facilitate these risks. Black women may be vulnerable to shame related to frequent racist experiences. Yet, no study to date has examined racism, shame, and stress reactivity in this population. The current study utilized mixed linear models to test for time and group effects of racism and shame on stress reactivity (e.g., cortisol and C-reactive protein [CRP]) among 34 Black women who completed the Trier Social Stress Test. Tests for two-way interactions (i.e., shame by racism) were also performed. Significant time and group effects were observed for shame and racism on stress reactivity. Black women who experienced greater lifetime racism, stress appraised, but lower racism during the past year, exhibited greater CRP responses. Black women who experienced high levels of shame and racism during the past year and their lifetime demonstrated greater cortisol reactivity. These results prompt further research on racism and shame as CVD risk factors among Black women.

Properties of tryptophan indole-lyase from a piezophilic bacterium, Photobacterium profundum SS9.

Tryptophan indole-lyase (Trpase), PBPRA2532, from Photobacterium profundum SS9, a piezophilic marine bacterium, has been cloned, expressed in Escherichia coli, and purified. The P. profundum Trpase (PpTrpase) exhibits similar substrate specificity as the enzyme from E. coli (EcTrpase). PpTrpase has an optimum temperature for activity at about 30°C, compared with 53°C for EcTrpase, and loses activity rapidly (t(1/2)∼30min) when incubated at 50°C, while EcTrpase is stable up to 65°C. PpTrpase retains complete activity when incubated more than 3h at 0°C, while EcTrpase has only about 20% remaining activity. Under hydrostatic pressure, PpTrpase remains fully active up to 100MPa (986atm), while EcTrpase exhibits only about 10% activity at 100MPa. PpTrpase forms external aldimine and quinonoid intermediates in stopped-flow experiments with l-Trp, S-Et-l-Cys, S-benzyl-l-Cys, oxindolyl-l-Ala, l-Ala and l-Met, similar to EcTrpase. However, with l-Trp a gem-diamine is observed that decays to a quinonoid complex. An aminoacrylate is observed with l-Trp in the presence of benzimidazole, as was seen previously with EcTrpase [28] but not with S-Et-l-Cys. The results show that PpTrpase is adapted for optimal activity in the low temperature, high pressure marine environment.