DNA-binding and protein structure of nuclear factors likely acting in genetic information processing in the Paulinella chromatophore.

The chromatophores in Paulinella are evolutionary-early-stage photosynthetic organelles. Biological processes in chromatophores depend on a combination of chromatophore and nucleus-encoded proteins. Interestingly, besides proteins carrying chromatophore-targeting signals, a large arsenal of short chromatophore-targeted proteins (sCTPs; <90 amino acids) without recognizable targeting signals were found in chromatophores. This situation resembles endosymbionts in plants and insects that are manipulated by host-derived antimicrobial peptides. Previously, we identified an expanded family of sCTPs of unknown function, named here "DNA-binding (DB)-sCTPs". DB-sCTPs contain a ~45 amino acid motif that is conserved in some bacterial proteins with predicted functions in DNA processing. Here, we explored antimicrobial activity, DNA-binding capacity, and structures of three purified recombinant DB-sCTPs. All three proteins exhibited antimicrobial activity against bacteria involving membrane permeabilization, and bound to bacterial lipids in vitro. A combination of in vitro assays demonstrated binding of recombinant DB-sCTPs to chromatophore-derived genomic DNA sequences with an affinity in the low nM range. Additionally, we report the 1.2 Å crystal structure of one DB-sCTP. In silico docking studies suggest that helix α2 inserts into the DNA major grove and the exposed residues, that are highly variable between different DB-sCTPs, confer interaction with the DNA bases. Identification of photosystem II subunit CP43 as a potential interaction partner of one DB-sCTP, suggests DB-sCTPs to be involved in more complex regulatory mechanisms. We hypothesize that membrane binding of DB-sCTPs is related to their import into chromatophores. Once inside, they interact with the chromatophore genome potentially providing nuclear control over genetic information processing.

Relationship Among Clinically Obtained Biomarkers of Inflammation, Hypercoagulability, and Macrophage Activation, and Delirium in Critically Ill Patients With COVID-19.

Critically ill patients with COVID-19 experience high rates of delirium and coma. Whether delirium occurs through novel mechanisms in COVID-19 is not known. We analyzed the relationship among biomarkers of inflammation (C-reactive protein [CRP]), hypercoagulability (d-dimer), and lung macrophage activation (ferritin), and the primary composite outcome of delirium/coma next day. We also measured associations between biomarkers and next day delirium and coma independently, and delirium severity. DESIGN: Retrospective, observational cohort study. SETTING: ICUs at two large, urban, academic referral hospitals. PATIENTS: All consecutive adult patients admitted to the ICU from March 1, 2020, to June 7, 2020, with COVID-19 with clinical biomarkers and delirium assessments performed. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Daily concentrations of CRP, d-dimer, and ferritin were obtained. Coma (assessed by Richmond Agitation-Sedation Scale) and delirium (assessed by Confusion Assessment Method for the ICU/Confusion Assessment Method for the ICU-7) were measured bid. A cohort of 197 ICU patients with COVID-19 were included. Higher d-dimer (odds ratio [OR], 1.57; 95% CI, 1.17-2.12; p < 0.01) and ferritin quartiles (OR, 1.36; 95% CI, 1.02-1.81; p < 0.01) were associated with greater odds of the composite outcome of delirium/coma next day. d-dimer was associated with greater odds of next day delirium (OR, 1.49; 95% CI, 1.14-1.94; p < 0.01) and coma independently (OR, 1.52; 95% CI, 1.08-2.14; p = 0.017). Higher ferritin quartiles were associated with greater odds of next day delirium (OR, 1.33; 95% CI, 1.04-1.70; p = 0.026) and coma independently (OR, 1.59; 95% CI, 1.14-2.23; p < 0.01). Higher CRP quartiles were associated with coma (OR, 1.36; 95% CI, 1.03-1.79; p = 0.030) and delirium severity the next day (ß = 0.30; se, 0.07; p ≤ 0.01). CONCLUSIONS: Our hypothesis-generating study found d-dimer and ferritin were associated with delirium/coma the following day, as well as delirium and coma independently. CRP was associated with next day coma and delirium severity. Larger studies to validate these results are needed.

Decreasing delirium through music listening (DDM) in critically ill, mechanically ventilated older adults in the intensive care unit: a two-arm, parallel-group, randomized clinical trial.

BACKGROUND: Delirium is a highly prevalent and morbid syndrome in mechanically ventilated intensive care unit (ICU) patients. Music is a promising non-pharmacological intervention with beneficial effects on anxiety and stress, while its effects on delirium duration and severity are not well understood. METHODS/DESIGN: Our study is a two-arm, randomized parallel-group, clinical trial to evaluate the efficacy of music intervention compared to a silence-track attention control on delirium/coma duration in mechanically ventilated critically ill older adults. One hundred sixty mechanically ventilated adults 50 years of age or older will be randomized to one of two arms within 72 h of ICU admission: (1) 1-h music listening sessions twice daily through noise-canceling headphones, or (2) 1-h sessions of a silence track twice daily through noise-canceling headphones. Our primary aim is to compare delirium/coma-free days after randomization during the 7-day study intervention phase using the Confusion Assessment Method for the ICU (CAM ICU) and the Richmond Agitation Sedation Scale (RASS) for delirium and coma. Secondary outcomes include pain and anxiety evaluated twice daily during the intervention phase and throughout the duration of ICU stay using the Critical Care Pain Observation Tool (CPOT) and visual analog scale-anxiety (VAS-A). Enrolled participants will be followed after hospital discharge to further measure cognition as well as screening for depression and anxiety using the following telephone-based instruments: Indiana University Telephone-Based Assessment of Neuropsychological Status (IU TBANS), Patient Health Questionnaire-9 (PHQ-9), and Generalized Anxiety Disorder-7 (GAD-7). DISCUSSION: This randomized clinical trial will measure the efficacy of a music listening intervention for delirium and coma duration early in the intensive care unit among older adults. TRIAL REGISTRATION: ClinicalTrials.gov. NCT04182334 .

Healthy Aging Brain Care Monitor, Caregiver Version: Screening for Post-Intensive Care Syndrome.

BACKGROUND: Cognitive impairment is common in intensive care unit survivors, pointing to the potential utility of a caregiver-based tool to screen for post-intensive care syndrome. OBJECTIVE: To validate the Healthy Aging Brain Care Monitor, Caregiver Version (HABC-M CG), as a caregiver-based tool to screen for post-intensive care syndrome. METHODS: A total of 116 patients who survived a stay in the intensive care unit completed standardized assessments of cognition, psychological symptoms, and physical functioning, and their caregivers completed the HABC-M CG. The Cronbach α was used to measure the internal consistency of the scale items. Validity of the HABC-M CG versus comparison tests was measured using the Spearman rank correlation. Generalized linear models were used to adjust for age, sex, and education level. RESULTS: The total scale and all subscales of the HABC-M CG showed excellent internal consistency (Cronbach α = 0.88-0.93). Scores on the psychological subscale correlated with standardized measures of depressive symptoms (Spearman ρ = 0.58). Scores on the cognitive subscale correlated with the Mini-Mental State Examination score (Spearman ρ = -0.33). Scores on the functional subscale correlated with scores on the Physical Self-Maintenance Scale (Spearman ρ = -0.36). CONCLUSION: The HABC-M CG is a valid informant-based clinical tool for the assessment of symptoms of post- intensive care syndrome.

Serum Biomarkers in Postoperative Delirium After Esophagectomy.

BACKGROUND: Esophagectomy is associated with postoperative delirium, but its pathophysiology is not well defined. We conducted this study to measure the relationship among serum biomarkers of inflammation and neuronal injury and delirium incidence and severity in a cohort of esophagectomy patients. METHODS: Blood samples were obtained from patients preoperatively and on postoperative days 1 and 3 and were analyzed for S100 calcium-binding protein B, C-reactive protein (CRP), interleukin (IL) 8 and IL-10, tumor necrosis factor-α, and insulin-like growth factor 1. Delirium was assessed twice daily using the Richmond Agitation Sedation Scale and Confusion Assessment Method for Intensive Care Unit. Delirium severity was assessed once daily with the Delirium Rating Scale-Revised-98. RESULTS: Samples from 71 patients were included. Preoperative biomarker concentrations were not associated with postoperative delirium. Significant differences in change in concentrations from preoperatively to postoperative day 1 were seen in IL-8 (delirium, 38.6; interquartile range [IQR], 29.3-69.8; no delirium, 24.8; IQR, 16.0-41.7, P = .022), and IL-10 (delirium, 26.1; IQR, 13.9-36.7; no delirium, 12.4; IQR, 7.7-25.7; P = .025). Greater postoperative increase in S100 calcium-binding protein B (Spearman r = 0.289, P = .020) and lower levels of insulin-like growth factor 1 were correlated with greater delirium severity (Spearman r = -0.27, P = .040). Greater CRP change quartiles were associated with higher delirium incidence adjusting for severity of illness (odds ratio, 1.68; 95% confidence interval, 1.03-2.75; P = .037) or comorbidities (odds ratio, 1.70; 95% confidence interval, 1.05-2.76, P = .030). CONCLUSIONS: Differences in change in serum CRP, IL-8, and IL-10 concentrations were associated with postoperative delirium, suggesting biomarker measurement early in the postoperative course is associated with delirium.