Publications

BACKGROUND: Timely resuscitation of patients in hemorrhagic shock is lifesaving. Blood product composition for massive transfusion protocols varies (whole blood versus conventional component therapy). Current whole blood inventory is predominantly RhD-positive, raising questions regarding the transfusion approach for females of childbearing potential (FCP).

STUDY DESIGN: Working groups were assembled that included experts in Trauma Surgery, Transfusion Medicine, Hematology, Maternal and Fetal Medicine, Emergency Medicine, Anesthesiology, Neonatology, and Pediatrics. Patient stakeholders and ethics representatives were included in each working group. An evidence review team at Johns Hopkins University performed systematic reviews and provided final reports. The Delphi method was used to refine recommendations and practice points for each key question that reflected consideration of the following factors: Balance of Benefits and Harms; Certainty of Evidence; Values and Preferences; Resource Use and Costs; Ethics, Equity; Feasibility.

RESULTS: Key questions addressed were: 1) strategies to increase blood donation and availability of RhD-negative blood products; 2) optimal blood product for FCPs in hemorrhagic shock whose RhD type is not known and RhD-negative LTOWB is not available; 3) indications for Rh immune globulin (RhIg) for post-exposure D-alloimmunization prophylaxis in RhD-negative FCPs who received RhD-positive blood products; 4) timing and performance of antibody screening following RhD-positive blood transfusion in RhD-negative FCPs. Herein, we report the detailed literature review and analysis, including articles screened, retrieved, assessed and included, as well as the recommendations with their rationale. Consensus was achieved for all recommendations and practice points.

CONCLUSIONS: These recommendations provide guidance for the optimal resuscitation and post-resuscitation care of FCP with life-threatening bleeding.

INTRODUCTION: Curcumin is a naturally occurring compound with anti-inflammatory, cholesterol-lowering, antidiabetic, and antioxidant properties. Curcumin can be biosynthesized in microbial hosts despite being found natively in Curcuma longa roots.

OBJECTIVES: It is unclear whether curcumin is transported out of microbial cells, binds to the inner or outer cell membrane, or accumulates inside. This study aims to gain a better understanding of curcumin's behavior after its formation in the host, which could lead to the development of new approaches to improve curcumin production.

MATERIAL AND METHODS: Advanced imaging techniques, including SEM, TEM, SHS, and TPF, were utilized to understand the behavior of curcumin within and outside of engineered Escherichia coli cells.

RESULTS: Curcumin was biosynthesized from ferulic acid in engineered E. coli BL21(DE3) by coexpressing 4-coumarate: CoA ligase and curcuminoid synthase. Second harmonic scattering (SHS) spectroscopy experiments utilized curcumin as a probe to investigate the surface binding of curcumin onto living E. coli cells with experimentally determined adsorption free energy, ΔG, values of -14.0 kcal/mol. By employing second harmonic and two-photon fluorescence imaging methods, the spatial distribution of curcumin aggregates was determined. Electron microscopy images revealed the presence of curcumin aggregates within the cells, at the surface, and in the media.

CONCLUSION: These experiments demonstrate that curcumin biosynthesis from ferulic acid leads to significant product aggregation within the cells, which could ultimately halt production by inducing cell death. Understanding the localization, transport, and removal of curcumin is crucial in developing more efficient biosynthetic pathways to enhance its production in microbial systems.

IMPORTANCE: Red blood cell alloimmunization is typically associated with the transplacental transfer of incompatible fetal red blood cells into maternal circulation. Subsequent pregnancies can be affected by fetal anemia, hydrops fetalis, and perinatal death. Most cases of Rhesus D (RhD) alloimmunization due to pregnancy can be prevented by the proper administration of Rhesus immune globulin. However, an emerging practice of using low-titer, O, RhD-positive whole blood (LTOWB) in cases of life-threatening hemorrhage has the potential to increase the exposure of the female population to a new source of incompatible red blood cells.

OBJECTIVE: To establish recommendations for the management of the red blood cell alloimmunized pregnancy.

EVIDENCE: Four working groups were assembled that included experts in (1) trauma and transfusion medicine, (2) hematology, (3) maternal-fetal medicine/obstetrics, and (4) neonatology. Patient stakeholders and ethics representatives were included in each working group. The patient/problem, intervention, comparison, outcome (PICO) framework was used to identify key clinical knowledge gaps. Library scientists at Johns Hopkins University performed systematic reviews and meta-analyses on these topics and provided final reports to the working groups. All 4 working groups participated in a Delphi process to refine recommendations and practice points for each PICO question that reflected consideration of the following factors: balance of benefits and harms; certainty of evidence; values and preferences; resource use and costs; ethics; equity; and feasibility.

FINDINGS: Seven clinical recommendations and 32 practice points were developed by the maternal-fetal medicine/obstetrics working group. Recommendations included the following: use of cell-free fetal DNA to identify the at-risk fetus early in pregnancy, followed by immunomodulation with intravenous immune globulin (IVIG) in select cases; the implementation of middle cerebral artery peak systolic velocity Doppler measurements to detect fetal anemia earlier in pregnancy; the use of IVIG in patients with a documented antigen-positive fetus with a history of either fetal anemia or a fetal loss due to hemolytic disease of the fetus and newborn before 24 weeks' gestational age in a previous pregnancy; the continuation of intrauterine transfusion therapy until the end of the 35th week of pregnancy; and prolonging gestational age to between 37 weeks 0 days and 38 weeks 6 days before proceeding to delivery.

CONCLUSIONS AND RELEVANCE: These recommendations provide an updated approach to the management of red blood cell alloimmunized pregnancies. The lack of high-quality evidence limits the strength of the recommendations but points to the need for a standardized approach to this rare disease.

Pseudomonas aeruginosa is a ubiquitous, Gram-negative bacterium that forms biofilms and is responsible for antibiotic-resistant nosocomial infections in humans. The P. aeruginosa BqsRS two-component system regulates biofilm formation and dispersal by sensing extracytoplasmic Fe 2+ , but the mechanistic details of this process are poorly understood. In this work, we report the crystal and solution structures of the Pa BqsR response regulator receiver domain, comprising a (βα) 5 response regulator assembly, and the DNA-binding domain, comprising a helix-turn-helix motif. Consistent with its cognate stimulus being Fe 2+ , we show that Pa BqsR binds directly to the promoter region of the feo operon that encodes the bacterial Fe 2+ transport system FeoABC. Corroborating these in vitro results, transcriptional studies show that Pa BqsR is a global regulator controlling many important genes in PAO1, including the feo operon. Intriguingly, promoter-based assays reveal that Pa BqsR is a dynamic regulator that responds to bioavailable Fe 2+ , likely through the ability of Pa BqsR to bind Fe 2+ directly via a His-rich motif, independent of the Pa BqsS membrane His kinase. This mode of regulation is unprecedented among OmpR-like response regulators but represents an important level of control over Fe 2+ acquisition in P. aeruginosa that could be an attractive therapeutic target to treat nosocomial infections.

Platelet transfusions are a cornerstone of modern medical care, yet the impacts of donor variability, manufacturing processes, and storage conditions on efficacy and safety remain to be comprehensively evaluated. In this review, the key factors contributing to the platelet storage lesion and recent clinical findings on cold-stored platelets are explored. Critical gaps in our understanding of platelet product function in hemostasis and beyond, including the roles of platelets in vascular integrity and thromboinflammation, are also highlighted. The impact of platelet product manufacturing and storage conditions on these domains is not yet understood. Furthermore, the need for improved preclinical models to assess storage-related functional changes is discussed and the importance of evaluating clinical outcomes associated with platelet storage lesions is emphasized. By addressing these challenges, clinicians can refine transfusion strategies through precision medicine and optimize platelet product selection and manufacturing to improve patient outcomes.

BACKGROUND: Rural America faces significant trauma outcome disparities, primarily driven by limited access to timely and appropriate care. Undertriage (UT) or the failure to transport severely injured patients to higher-level trauma centers further exacerbates these inequities. This study investigates the role of social determinants of health in influencing UT, hypothesizing that increased social deprivation correlates with higher UT rates.

METHODS: Retrospective cohort study of injured patients transported by emergency medical services in Pennsylvania between 2000 and 2020 who met physiologic or anatomic National Field Triage Guidelines criteria for transport to a trauma center. Undertriage was defined as patients not initially transported to a level I or II trauma center. Logistic regression determined the association between the social deprivation index (SDI) and UT at both the patient and zip code levels. In addition, we applied Bayesian spatial models to explore regional patterns and influences on UT.

RESULTS: The cohort included 166,632 trauma patients, with 29% experiencing UT. At the patient level, a 10-point increase in SDI (more deprivation) was associated with a 1.4% rise in the odds of UT (adjusted odds ratio, 1.014; 95% confidence interval, 1.002-1.026; p = 0.025). At the zip code level, SDI emerged as a significant predictor of UT rates (coefficient, 0.380; 95% CI, 0.0165-0.0595; p = 0.001), with spatial autocorrelation observed (Moran's I = 0.732, p < 0.0001). Bayesian spatial models revealed an association between regional SDI and UT, reinforcing the role of geographic and socioeconomic factors. Undertriage was linked to increased mortality, higher complication rates, and prolonged hospital stays (p < 0.05).

CONCLUSION: Undertriage is associated with more disadvantaged social determinants of health. This work highlights a critical opportunity to mitigate trauma disparities. Policy efforts should prioritize disseminating standardized triage guidelines, leveraging geospatial data for targeted interventions, and exploring air medical transport to improve access to care without overburdening ground emergency medical services systems.

LEVEL OF EVIDENCE: Epidemiological; Level IV.