We introduce a high-resolution adult foraging assay (AFA) that relates pre- and post-ingestive walking behavior to individual instances of food consumption. We explore the utility of the AFA by taking advantage of established rover and sitter strains known to differ in a number of feeding-related traits. The AFA allows us to effectively distinguish locomotor behavior in Fed and Food-Deprived (FD) rover and sitter foragers. We found that rovers exhibit more exploratory behavior into the center of an arena containing sucrose drops compared to sitters who hug the edges of the arena and exhibit thigmotaxic behavior. Rovers also discover and ingest more sucrose drops than sitters. Sitters become more exploratory with increasing durations of food deprivation and the number of ingestion events also increases progressively with prolonged fasting for both strains. AFA results are matched by strain differences in sucrose responsiveness, starvation resistance, and lipid levels, suggesting that under the same feeding condition, rovers are more motivated to forage than sitters. These findings demonstrate the AFA's ability to effectively discriminate movement and food ingestion patterns of different strains and feeding treatments.

Background Circulating cell-free DNA (cfDNA) may contribute to the pathophysiology of post-injury inflammation and coagulation in trauma. However, the source and mechanism of release of cfDNA in trauma is not well understood. One potential source of cfDNA is from Neutrophil Extracellular Traps (NETs), released by activated neutrophils during the process of NETosis. The primary objective of our study was to determine if cfDNA has prognostic utility in trauma. The secondary objective of this study was to determine the source of cfDNA in trauma compared to sepsis. Methods We studied trauma patients from two prospective observational cohort studies: the DNA as a Prognostic Marker in ICU Patients (DYNAMICS) study and the Endotoxin in Polytrauma (ENPOLY) study. We also studied septic patients from the DYNAMICS study. Citrated plasma samples were collected longitudinally from the patients (days 1 to 7). The following molecules were measured in the plasma samples: cfDNA, protein C (PC), myeloperoxidase (MPO) (a marker of neutrophil activation), citrullinated Histone H3 (H3Cit, a marker of NETosis), cyclophilin A (a marker of necrosis), and caspase-cleaved K18 (a marker of apoptosis). Results A total of 77 trauma patients were included ( n = 38 from DYNAMICS and n = 39 from ENPOLY). The median age was 49 years; 27.3% were female, and mortality was 16.9% at 28 days. Levels of cfDNA were elevated compared to healthy values but not significantly different between survivors and non-survivors. There was a positive correlation between MPO and cfDNA in septic patients ( r = 0.424, p < 0.001). In contrast, there was no correlation between MPO and cfDNA in trauma patients ( r = – 0.192, p = 0.115). Levels of H3Cit, a marker of NETosis, were significantly elevated in septic patients compared to trauma patients ( p < 0.01) while apoptosis and necrosis markers did not differ between the two groups. Conclusion Our studies suggest that the source and mechanism of release of cfDNA differ between trauma and sepsis patients. In sepsis, cfDNA is likely primarily released by activated neutrophils via the process of NETosis. In contrast, cfDNA in trauma appears to originate mainly from injured or necrotic cells. Although cfDNA is elevated in trauma and sepsis patients compared to healthy controls, cfDNA does not appear to have prognostic utility in trauma patients. Trial registration ClinicalTrials.gov Identifier: NCT01355042 . Registered May 17, 2011 Electronic supplementary material The online version of this article (10.1186/s40635-019-0251-4) contains supplementary material, which is available to authorized users.

Tranexamic acid (TXA) is an antifibrinolytic agent commonly used for the treatment or prevention of bleeding. Indications for TXA are diverse, including heavy menstrual bleeding, trauma, postpartum hemorrhage, traumatic brain injury, and surgical site bleeding. Despite decades of use and a robust body of evidence, hesitancy using TXA persists in many clinical settings. This illustrated review describes the history, pharmacology, and practical considerations of TXA use. We also describe the major landmark randomized controlled trials of TXA and their implications. Finally, we review the evidence around common controversies surrounding TXA such as the risk of thrombosis, prescription along with combined hormonal contraceptives, and use in patients with gross hematuria.

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During macrophage development, myeloid progenitor cells undergo terminal differentiation coordinated with reduced cell cycle progression. Differentiation of macrophages from myeloid progenitors is accompanied by increased expression of the E26 transformation-specific transcription factor PU.1. Reduced PU.1 expression leads to increased proliferation and impaired differentiation of myeloid progenitor cells. It is not understood how PU.1 coordinates macrophage differentiation with reduced cell cycle progression. In this study, we utilized cultured PU.1-inducible myeloid cells to perform genome-wide chromatin immunoprecipitation sequencing (ChIP-seq) analysis coupled with gene expression analysis to determine targets of PU.1 that may be involved in regulating cell cycle progression. We found that genes encoding cell cycle regulators and enzymes involved in lipid anabolism were directly and inducibly bound by PU.1 although their steady-state mRNA transcript levels were reduced. Inhibition of lipid anabolism was sufficient to reduce cell cycle progression in these cells. Induction of PU.1 reduced expression of E2f1, an important activator of genes involved in cell cycle and lipid anabolism, indirectly through microRNA 223. Next-generation sequencing identified microRNAs validated as targeting cell cycle and lipid anabolism for downregulation. These results suggest that PU.1 coordinates cell cycle progression with differentiation through induction of microRNAs targeting cell cycle regulators and lipid anabolism. KEYWORDS E2F1, microRNA, PU.1, cell cycle, differentiation, lipid synthesis, myeloid cells A central problem in biology is understanding how cell division is regulated in response to developmental and environmental cues. During macrophage development, proliferating myeloid progenitor cells undergo terminal differentiation that is coordinated with reduced cell cycle progression (1). However, terminally differentiated macrophages are not necessarily permanently cell cycle arrested, as shown by evidence that epidermal Langerhans cells and brain microglia can reenter the cell cycle to self-renew (2, 3). Thus, cell cycle arrest and terminal differentiation, while normally coincident, can be independently and actively regulated. Much remains to be learned about the mechanisms by which cell-type-specific transcription factors coordinate cell cycle arrest with differentiation.

BACKGROUND Anemia is common in critically ill patients and associated with adverse outcomes. Phlebotomy associated with laboratory testing is a potentially modifiable contributor. This study aims to 1) characterize the blood volume taken for laboratory testing, and 2) explore the effect of blood loss on red blood cell (RBC) transfusion and anemia in adult intensive care unit (ICU) patients. METHODS Using a transfusion research database, we retrospectively reviewed consecutively admitted patients to four medical‐surgical ICUs in Hamilton, Ontario, Canada. The primary outcome was estimated blood loss for laboratory testing during ICU admission. Secondary outcomes were hemoglobin (Hb) of 90 g/L or less and RBC transfusion. RESULTS Among the 7273 patients included, the median blood volume per patient taken for laboratory testing during their ICU stay was 213 mL (interquartile range [IQR], 133‐382 mL). On ICU admission, median Hb was 97 g/L (IQR, 82‐116 g/L). An Hb of 90 g/L or less occurred in 67.0% of patients during their ICU stay. Median Hb on ICU discharge adjusted for RBC transfusion was 84 g/L (IQR, 58‐105 g/L). RBC transfusion was administered to 47.5% of patients, who received a median of 3 units (IQR, 2‐7 units). Cumulative blood loss due to laboratory testing from Day 2 to Day 7 of ICU admission was independently associated with RBC transfusion (hazard ratio, 2.28 for each 150‐mL increment; 95% confidence interval, 2.02–2.59). CONCLUSIONS Blood loss for laboratory testing is substantial in ICU patients and significantly associated with RBC transfusion. Strategies to reduce blood loss from laboratory testing represents an area for further investigation.

Background: A limitation of diagnostic scoring systems for disseminated intravascular coagulation (DIC) is that once DIC is identified, it may be in a state of irreversible deterioration. Objectives: To identify hemostatic markers that can identify the pre-DIC state. Methods: This was a multi-center observational study of 357 septic patients. The incidence of DIC was determined using the International Society on Thrombosis and Haemostasis (ISTH) DIC Score. Markers of interest include components of the DIC score: protein C (PC), antithrombin (AT), and citrullinated histones (H3Cit), which is a marker of NETosis. Results: Out of 357 sepsis patients, 236 patients did not develop DIC (without-DIC), 79 patients had DIC on Day 1 (overt-DIC), and 42 patients developed DIC after Day 1 (pre-DIC). Compared to without-DIC patients, pre-DIC patients had decreased platelet count, increased international normalized ratio (INR), decreased PC and AT, and increased H3Cit. In contrast, D-dimer and fibrinogen levels did not differ between pre-DIC and without-DIC patients. Using receiver operating characteristics (ROC) analysis, we found that platelet count and INR in combination with PC and AT could discriminate pre-DIC from without-DIC. The area under the curve in the ROC analysis was 0.83 (95% confidence interval, 0.76 to 0.89). Conclusion: Our study suggests that platelets and INR in combination with PC and AT can identify the pre-DIC state in septic patients. In contrast, D-dimer increased and fibrinogen decreased in the late (ie, overt) stages of DIC. Our data also suggest that NETosis contributes to the onset of DIC in sepsis.

Background: Intensive care unit (ICU) patients are at high risk of anemia, which is associated with adverse clinical outcomes and death. Blood sampling for diagnostic testing is a potentially modifiable contributor to anemia. Methods: We conducted a systematic review by searching MEDLINE and EMBASE from inception to October 5, 2017, for studies reporting the volume of blood taken for laboratory testing using blood sampling conservation devices compared to standard care or another intervention in adult ICU patients. Results: We identified 8 eligible studies (n = 1204 patients) that used 2 types of devices: arterial access devices (n = 5) and reduced-volume blood collection tubes (n = 3). All studies reported a reduction in the volume of blood taken for laboratory testing with devices compared to standard practice (range 19%-80%). The studies were judged to have serious risk of bias, and due to heterogeneity, pooling for meta-analysis was not considered appropriate. Conclusions: Devices used to reduce the volume of blood taken for laboratory testing in ICU patients appear to be effective, although study heterogeneity limited our ability to calculate pooled estimates of efficacy for each device. Further assessment of clinical outcomes may establish clinical benefit with minimal negative consequences for hospitals and laboratories to facilitate the use of small-volume tubes.