Generation of LexA enhancer-trap lines in Drosophila by an international scholastic network

Conditional gene regulation in Drosophila through binary expression systems like the LexA-LexAop system provides a superb tool for investigating gene and tissue function. To increase the availability of defined LexA enhancer trap insertions, we present molecular, genetic, and tissue expression studies of 301 novel Stan-X LexA enhancer traps derived from mobilization of the index SX4 line. This includes insertions into distinct loci on the X, II, and III chromosomes that were not previously associated with enhancer traps or targeted LexA constructs, an insertion into ptc, and seventeen insertions into natural transposons. A subset of enhancer traps was expressed in CNS neurons known to produce and secrete insulin, an essential regulator of growth, development, and metabolism. Fly lines described here were generated and characterized through studies by students and teachers in an international network of genetics classes at public, independent high schools, and universities serving a diversity of students, including those underrepresented in science. Thus, a unique partnership between secondary schools and university-based programs has produced and characterized novel resources in Drosophila, establishing instructional paradigms devoted to unscripted experimental science.

A47 THE GUT MICROBIOTA INFLUENCES COLONIC HEALING AFTER SURGERY IN PATIENTS UNDERGOING BOWEL RESECTION FOR COLORECTAL CANCER

Background

The standard treatment of colorectal cancer (CRC) consists of a surgical resection of the colonic segment with the tumor, followed by a reconnection of the remaining bowel ends, or "anastomosis". The anastomosis may fail to heal in up to 20% of patients, which leads to anastomotic leak, a major complication that increases postoperative morbidity and mortality. This complication is unpredictable and its causes remain poorly understood.

Purpose

The objective of this study is to investigate the possible role of the gut microbiome in anastomotic healing after surgery in patients with CRC.

Method

We collected preoperative fecal samples and intraoperative mucosal samples from CRC patients undergoing surgery with anastomosis. The gut microbiota of patients with AL and of others that presented optimal healing after surgery was analyzed and compared using the Anchor 16S pipeline. To assess the role of the patients' microbiota in healing, fecal microbiota transplantation (FMT) was performed in mice using preoperative fecal samples from CRC patients with and without AL. Mice were then subjected to colonic surgery using a colonic anastomosis model. Six days after surgery, anastomotic healing was assessed macroscopically and microscopically. The gut barrier function was also assessed. The gut microbiota composition was compared between the groups colonized with samples from patients with and without AL to detect potential differences.

Result(s)

Mice colonized by FMT with the microbiota of donors with AL displayed poor anastomotic healing macroscopically, and a weaker wound microscopically. These same mice displayed a weaker gut barrier, as objectified by higher bacterial translocation to the spleen. The anastomoses of mice receiving the microbiota of AL donors displayed lower concentrations of collagen and fibronectin and higher inflammatory cytokines and collagenolytic enzymes, indicating poor extracellular matrix formation and collagen degradation locally.The beta-diversity of the gut microbiota was significantly different between mice receiving the microbiota of donors with and without AL, and several bacterial species were differentially abundant between the two groups.

Conclusion(s)

The preoperative gut microbiota in CRC patients who experience anastomotic leak after surgery induces poor anastomotic healing in mice and a weaker gut barrier after colonic surgery. Several bacterial species were found to be associated with the healing process.

Please acknowledge all funding agencies by checking the applicable boxes below

CIHR, Other

Please indicate your source of funding;

NSERC, FRQS, New Frontiers in Research, Montreal Cancer Institute.

Disclosure of Interest

None Declared

Efficiency of the EmERGE Pathway to provide continuity of care for Spanish people living with medically stable HIV

OBJECTIVE

Calculate the efficiency of the EmERGE Pathway of Care for medically stable people living with HIV at the Hospital Clínic-IDIBAPS, Barcelona, Spain.

METHODS

546 study participants were followed between 1st July 2016 and 30th October 2019 across three HIV outpatient clinics, but the virtual clinic was closed during the second year. Unit costs were calculated, linked to mean use outpatient services per patient year, one-year before and after the implementation of EmERGE. Costs were combined with primary and secondary outcomes.

RESULTS

Annual costs across HIV-outpatient services increased by 8%: €1073 (95%CI €999-€1157) to €1158 (95%CI €1084-€1238). Annual cost of ARVs was €7,557; total annual costs increased by 1% from €8430 (95%CI €8356-8514) to €8515 (95%CI €8441-8595). Annual cost for 433 participants managed in face-to-face (F2F) clinics decreased by 5% from €958 (95%CI 905-1018) to €904 (95%CI 863-945); participants transferred from virtual to F2F outpatient clinics (V2F) increased their annual cost by a factor of 2.2, from €115 (95%CI 94-139) to €251 (95%CI 219-290). No substantive changes were observed in primary and secondary outcomes.

CONCLUSION

EmERGE Pathway is an efficient and acceptable intervention. Increases in costs were caused by internal structural changes. The cost reduction observed in F2F clinics were off-set by the transfer of participants from the virtual to the F2F clinics due to the closure of the virtual clinic during the second year of the Study. Greater efficiencies are likely to be achieved by extending the use of the Pathway to other PLHIV.

O-259 Free and extracellular vesicle-associated microRNAs from endometrial fluid as non-invasive diagnostic biomarkers of implantative endometrium

Study question

Is it possible to use free and extracellular vesicle-associated microRNAs from endometrial fluid as non-invasive biomarkers for implantative endometrium?

Summary answer

It is feasible to use free and extracellular vesicle-associated miRNAs as non-invasive tools for the detection of an implantative endometrium.

What is known already

MicroRNAs (miRNAs) and extracellular vesicles (EVs) from endometrial fluid (EF) have been described as mediators of embryo-endometrial crosstalk. Therefore, the miRNA analysis of EF could provide a non-invasive technique for recognizing an implantative endometrium and consequently improve implantation rates.

Study design, size, duration

A cohort of 162 women who assisted the human reproduction unit from January 2018 to February 2021. Of them, 72 participated in the setup and samples were collected before starting any fertility treatment in natural cycles. For the discovery of the predicted models (n = 30) and validation (n = 60), the EF was obtained from women undergoing frozen embryo transfer on day 5 and the sample was collected immediately before embryo transfer.

Participants/materials, setting, methods

We compared five different methodologies, two of which consisted of direct RNA extraction while the other three had EV enrichment prior to RNA extraction. A smallRNA-seq was performed to determine the most efficient method and to find a predictive model to differentiate between implantation and non-implantation endometrium. The models were confirmed by qPCR in two set of samples, discovery and validation cohorts with a different implantation outcome.

Main results and the role of chance

Our results showed that EV-enrichment protocols permit detection of a higher number of miRNAs. In addition, we obtained two predictive models based on three miRNAs that allow us to differentiate between an implantative and non-implantative endometrium. Results for model 1 in discovery cohort were: AUC=0.93; p-value = 0.003 and in validation cohort were: AUC= 0.69; p-value = 0.019. Results for model 2 in discovery cohort were: AUC=0.92; p-value = 0.0002 and in validation cohort were: AUC= 0.78; p-value= 0.0002.

Limitations, reasons for caution

One limitation to consider is the inherent variability of both the women involved in the trial and the embryos transferred. In our study, we have previously selected embryos based on morphology but we lacked genetic and molecular studies, a good complement that will certainly improve our test’s accuracy.

Wider implications of the findings

This study introduces new protocols to analyze miRNAs from very small volumes of EF, which could be implemented in clinical practice for the assessment of the endometrial status using miRNA-based non-invasive tools. Our results suggest that with model-2 it is possible to identify a non-implantative endometrium with 0.6-sensitivity and 0.93-specificity.

Trial registration number

not applicable

Use of diamond sensors for a high-flux, high-rate X-ray pass-through diagnostic

X-ray free-electron lasers (XFELs) deliver pulses of coherent X-rays on the femtosecond time scale, with potentially high repetition rates. While XFELs provide high peak intensities, both the intensity and the centroid of the beam fluctuate strongly on a pulse-to-pulse basis, motivating high-rate beam diagnostics that operate over a large dynamic range. The fast drift velocity, low X-ray absorption and high radiation tolerance properties of chemical vapour deposition diamonds make these crystals a promising candidate material for developing a fast (multi-GHz) pass-through diagnostic for the next generation of XFELs. A new approach to the design of a diamond sensor signal path is presented, along with associated characterization studies performed in the XPP endstation of the LINAC Coherent Light Source (LCLS) at SLAC. Qualitative charge collection profiles (collected charge versus time) are presented and compared with those from a commercially available detector. Quantitative results on the charge collection efficiency and signal collection times are presented over a range of approximately four orders of magnitude in the generated electron-hole plasma density.

Effectiveness of Child-Focused Interventions for Externalizing Behavior: a Rapid Evidence Review

Parent behavior management training (BMT) is well established as an effective, evidence-based treatment for children with externalizing behavior. Despite the wealth of data supporting BMT, many community providers use a variety of child-focused and non-directive interventions to target behavior problems. There is lack of clarity as to whether the evidence supporting child-focused externalizing treatments is sufficiently compelling to support offering these treatments rather than or in addition to BMT. This rapid evidence review compares the effectiveness of BMT with several common child-focused interventions for externalizing behavior including cognitive behavioral (CBT), social skill (SS), and play/dynamic (PT) approaches. PubMed, PsychINFO, and Web of Science were searched for English-language articles from year 2000 onwards for each intervention type. Inclusion criteria were child age (12 and under), presence of a child-focused behavioral treatment condition, and externalizing behavior as an outcome variable. A total of 30 studies met inclusion criteria and were coded (13 CBT, 10 SS, 7 PT). Results supported social skills interventions with accompanying BMT as effective in improving externalizing problems, with generally moderate effect sizes. Individual social skills interventions were promising but needing further evaluation compared to treatment as usual. CBT treatments with and without accompanying BMT showed moderate effects over waitlist but produced less consistently significant effects compared to more robust controls. Play therapy approaches showed inconsistent effects and require further evaluation. This review supports social skills plus BMT treatments as a child-focused intervention with probable efficacy for child externalizing problems. Implications for policy and community practice are discussed.

Psychosocial Well-Being: An Exploratory Cross-Sectional Evaluation of Loneliness, Anxiety, Depression, Self-Compassion, and Professional Quality of Life in Oncology Nurses

BACKGROUND

In addition to heavy workloads, oncology nurses are confronted with emotionally demanding caregiving moments with little training or institutional support for coping and emotional well-being.

OBJECTIVES

The aim of this study was to explore the associations and potential predictors among self-compassion, loneliness, anxiety, depression, and professional quality of life in oncology nurses.

METHODS

Participants were recruited throughout central Texas. Descriptive statistics, bivariate correlations, and multivariate regression analyses were conducted on survey data.

FINDINGS

Burnout and compassion satisfaction were strongly related to loneliness, self-compassion, and depression. Compassion fatigue was most highly related to anxiety and depression. Loneliness made the strongest unique contribution to burnout and compassion satisfaction, and depression was the only statistically significant predictor of compassion fatigue.

Reanalysis of the Mars500 experiment reveals common gut microbiome alterations in astronauts induced by long-duration confinement

Maintaining astronaut health throughout long-duration spaceflight is essential to the feasibility of a manned mission to Mars. The ground-based Mars500 experiment investigated long-duration health by isolating six astronauts for 520 days, the longest controlled human confinement study conducted to date. After 520 days, astronauts had uniform strength and lean body mass losses, and increased fasting plasma glucose, calprotectin, and neutrophil levels characteristic of intestinal inflammation but previous analyses revealed no common significant changes in gut microbiota. This study reanalysed data from early (days 7–45) and late (days 420–520) faecal samples and identified 408 exact sequence variants (ESVs), including 213 shared by all astronauts. Thirty-two ESVs were significantly differentially abundant over time, including depletion of keystone resistant starch degrading, anti-inflammatory and insulin sensitivity-associated species, such as Faecalibacterium prausnitzii, Ruminococcus bromii, Blautia luti, Anaerostipes hadrus, Roseburia faecis, and Lactobacillus rogosae, and enrichment of yet-to-be-cultured bacteria. Additionally, the extraordinary experimental confinement allowed observation of microbiota potentially shared between astronauts and their habitat. Forty-nine species were shared, representing 49% and 12% of the human and environmental microbiome diversity, respectively. These findings reveal the microbiota which significantly altered in relative abundance throughout confinement, including species known to influence inflammation and host glucose homeostasis consistent with astronaut symptoms. Identification of microbiome alterations after 520 days of isolation represents a missing piece connecting Mars500 astronaut physiological studies. Knowledge of the impact of long-term confinement upon the human microbiome helps to improve our understanding of how humans interact with their habitats and is a valuable step forward towards enabling long-duration spaceflight.

Efficiency of the EmERGE Pathway to provide continuity of care for Spanish people living with medically stable HIV

OBJECTIVE

Calculate the efficiency of the EmERGE Pathway of Care for medically stable people living with HIV at the Hospital Clínic-IDIBAPS, Barcelona, Spain.

METHODS

546 study participants were followed between 1st July 2016 and 30th October 2019 across three HIV outpatient clinics, but the virtual clinic was closed during the second year. Unit costs were calculated, linked to mean use outpatient services per patient year, one-year before and after the implementation of EmERGE. Costs were combined with primary and secondary outcomes.

RESULTS

Annual costs across HIV-outpatient services increased by 8%: €1073 (95%CI €999-€1157) to €1158 (95%CI €1084-€1238). Annual cost of ARVs was €7,557; total annual costs increased by 1% from €8430 (95%CI €8356-8514) to €8515 (95%CI €8441-8595). Annual cost for 433 participants managed in face-to-face (F2F) clinics decreased by 5% from €958 (95%CI 905-1018) to €904 (95%CI 863-945); participants transferred from virtual to F2F outpatient clinics (V2F) increased their annual cost by a factor of 2.2, from €115 (95%CI 94-139) to €251 (95%CI 219-290). No substantive changes were observed in primary and secondary outcomes.

CONCLUSION

EmERGE Pathway is an efficient and acceptable intervention. Increases in costs were caused by internal structural changes. The cost reduction observed in F2F clinics were off-set by the transfer of participants from the virtual to the F2F clinics due to the closure of the virtual clinic during the second year of the Study. Greater efficiencies are likely to be achieved by extending the use of the Pathway to other PLHIV.

Quality of life in patients with resectable rectal cancer during the first 24 months following diagnosis

AIM

An increasing number of patients survive rectal cancer, resulting in more patients living with the side-effects of the treatment. Exploring quality of life before and after treatment enables follow-up and additional treatment to be adjusted to the patient's needs. The aim of the study was to describe the quality of life during the 24 months following diagnosis and to identify risk factors for poor quality of life.

METHOD

This is a prospective cohort study of patients with rectal cancer followed up by extensive questionnaires. Patients from 16 surgical departments in Denmark and Sweden from 2012 to 2015 were included. The self-assessed quality of life was measured with a seven-point Likert scale.

RESULTS

A total of 1110 patients treated with curative intent were included, and the response rate at the 24-month follow-up was 71%. Patients with rectal cancer assessed their quality of life before start of treatment as poorer than that of a reference population. At the 12- and 24-month follow-up, the quality of life on group level had recovered to the same level as for the reference population. Risk factors for poor quality of life included bother with urinary, bowel and stoma function. A reference population was used for comparison.

CONCLUSION

The quality of life of patients with resectable rectal cancer recovered to levels comparable to a reference population 12 and 24 months after diagnosis. Our results indicate that the urinary, bowel and stoma function has an impact on quality of life.

Relationship between electrocardiogram changes and myocardial edema in tako-tsubo syndrome

Introduction

During the acute phase of Tako-tsubo syndrome (TTS) electrocardiogram (ECG) features change and myocardial edema is a common finding in Cardiac Magnetic Resonance (CMR). However, the relationship between ECG changes and myocardial edema is still unclear.

Purpose

To define if the presence and extension of myocardial edema might be predicted by electrocardiographic changes since admission to CMR.

Methods

Consecutive patients with TTS undergoing CMR during hospitalization were included. All patients underwent serial electrocardiography during the acute phase. Myocardial edema presence and extension was assessed by expert observers using the 17-segments cardiac segmentation model. ECG were analysed by expert observers blinded to the presence of myocardial edema. ECG pattern as predictors of myocardial edema presence and its extension were analysed by a binary regression and Student's t test.

Results

A total of 42 patients were included. Admission cQT was 472±60 ms. Thirty patients (71%) developed widespread negative T-waves and 55% showed cQT prolongation (cQT 476±58 ms) by the time of CMR. The median (IQR) time from admission to CMR imaging was 5 days (2–7 days). Myocardial edema was found in 30 patients (71%) and mean number of myocardial segments affected by edema was 4.8±2.5. Widespread negative T-wave development at the time of CMR imaging was associated with a smaller number of myocardial segments with edema. However no significant correlation was found between extension of myocardial edema and QT prolongation. No ECG pattern predicted a full recovery of myocardial edema (Table).

Conclusions

Development of widespread negative T-wave at the time of CMR predicts smaller myocardial edema extension. However, no other ECG features by the time of CMR were able to predict the full recovery of myocardial edema.

Funding Acknowledgement

Type of funding source: None

Co-cropping with three phytoremediation crops influences rhizosphere microbiome community in contaminated soil

Human industrial activities have left millions of hectares of land polluted with trace element metals and persistent organic pollutants (POPs) around the world. Although contaminated sites are environmentally damaging, high economic costs often discourage soil remediation efforts. Phytoremediation is a potential green technology solution but can be challenging due to the diversity of anthropogenic contaminants. Co-cropping could provide improved tolerance to diverse soil challenges by taking advantage of distinct crop capabilities. Co-cropping of three species with potentially complementary functions, Festuca arundinacea, Salix miyabeana and Medicago sativa, perform well on diversely contaminated soils. Here, rhizosphere microbiomes of each crop in monoculture and in all co-cropping combinations were compared using 16S rRNA gene amplification, sequencing and differential abundance analysis. The hyperaccumulating F. arundinacea rhizosphere microbiome included putative plant growth promoting bacteria (PGPB) and metal tolerance species, such as Rhizorhapis suberifaciens, Cellvibrio fibrivorans and Pseudomonas lini. The rhizosphere microbiome of the fast-growing tree S. miyabeana included diverse taxa involved in POP degradation, including the species Phenylobacterium panacis. The well-characterised nitrogen-fixing M. sativa microbiome species, Sinorhizobium meliloti, was identified alongside others involved in nutrient acquisition and putative yet-to-be-cultured Candidatus saccharibacteria (TM7-1 group). The majority of differentially abundant rhizosphere-associated bacterial species were maintained in co-cropping pairs, with pairs having higher numbers of differentially abundant taxa than monocultures in all cases. This was not the case when all three crops were co-cropped, where most host-specific bacterial species were not detected as differentially abundant, indicating the potential for reduced rhizosphere functionality. The crops cultivated in pairs here retained rhizosphere microbiome bacteria involved in these monoculture ecosystem services of plant growth promotion, POP tolerance and degradation, and improved nutrient acquisition. These findings provide a promising outlook of the potential for complementary co-cropping strategies for phytoremediation of the multifaceted anthropogenic pollution which can disastrously affect soils around the world.

Abstract P6-08-37: A new workflow for breast cancer genetic counseling referral. Experience of an public oncological reference center in Argentina

Background: Argentina is a country with inequalities in terms of healthcare, specially in genetics diseases. The lack of knowledge about hereditary cancer, the small number of genetic counselors and the difficulty of access to genetic testing are barriers to overcome to position genetic counseling (GC) as a standard of care. Objective: Describe our experience implementing GC as a standard of care for all patients with breast cancer (BC), and propose a new workflow to optimize referral to GC. The aim is to obtain GC and genetic testing prior to the primary treatment. Methods: In January 2015, the breast cancer unit established GC as a standard of care on all their patients. The institution didn’t have GC, so a breast cancer surgeon, part of the core team, was trained in GC and the rest of the team was trained to refer patients according to international guidelines. That surgeon and a psycho-oncologist formed the breast cancer genetic counseling section (BCGCS). They have interviewed patients and their families and have supported them and their medical team all over the GC process and testing. Results: From January 2015 to December 2018, 535 patients were evaluated by the BCGCS. 63% of patients were refered by breast surgeons, 12% by clinical oncologist, 19% by other units, 1% by the patients themselves and 5% from other institutions. The average time until the first GC consultation was 35 days (1-60 days). A minimum of two GC consultations per patient were performed. 243 patients were referred for genetic testing and 280 were not (27 without criteria, 35 were not index case, 19 psychological reasons and 147 patients were requested additional information). From the 243 patients, 139 didn’t have access to genetic testing due to lack of health insurance coverage. 104 test were successfully performed: 2 exomes (2 VUS: CHEK2 and TSC2), 81 BRCA1/2 (20 positives), 8 panels (3 VUS: ATM, RECQL, STK11) and 13 family mutations (5 positives: 4 BRCA and 1 CHEK2). Only two patients had a positive BRCA test before their primary treatment, both chose a bilateral mastectomy and one of them was included in the Olympia trial. Due to the success of the BCGCS, in 2017 a gynecologist and in 2018 an oncologist were trained in GC. The first one is part of the gynecological cancer unit and the second is part of the gastrointestinal cancer unit. Conclusion: Due to the presence of trained professionals as part of core teams, those units were continuously educated in genetics. That led to more and earlier referral to GC. We propose the following workflow to achieve better and more referrals of patients to GC, optimizing time and resources. Proposed WorkflowBackground requirements: Surgeon specialized in breast cancer trained in GC and Psycho-oncologist with basic knowledge of cancer genetics. Breast unit trained in hereditary cancer and referral guidelines.-Step one) Admission to breast unit with identification of patients with genetic counseling criteria according with national and international guidelines. *-Step two) Treatment Focus Genetic Testing is needed? (metastatic breast cancer, triple negative breast cancer, breast and ovarian cancer)1) Yes (always request psycho-logical support and explain the workflow)1A) Had family history of cancer?(1Aa) Yes: request a limited panel (BRCA1 / 2, PALB2, Tp53, Pten and other gene if an other syndrome is suspected) and send it to BCGCS**(1Ab) No: request BRCA1 / 2 and PALB2 testing(1Abi) Negative result. End of process(1Abii) Positive result or VUS: send to BCGCS**2) No: send to BCGCS.*** Rapid genetic testing is strongly encouraged.** Always explain about genetic counseling process and information needed prior to consultation.

Citation Format: Maria Dolores Mansilla Figueroa, D Bequelman, J Cavallero, O Sturla, H Ursino, V Caceres, E Gonzalez. A new workflow for breast cancer genetic counseling referral. Experience of an public oncological reference center in Argentina [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-08-37.

Bio-based Algae Oil: an oxidation and structural analysis

OBJECTIVE

In search of natural components, vegetal oils are increasingly becoming more popular in cosmetics. However, high oxidation instability, presence of potential allergens and synthetic anti-oxidants have limited their applications so far. Therefore, a need exists for a natural emollient with high oxidation stability. In this work, we report on a novel sustainably produced triglyceride containing primarily three monounsaturated oleic acid chains, dubbed 'Bio-Based Algae Oil' hereafter, as a natural emollient for cosmetic formulations. To produce Bio-Based Algae Oil, simple sugars are converted into triglyceride oils using microalgae fermentation with minimal environmental impact.

METHODS

Bio-Based Algae Oil was compared to other commonly used triglyceride-based emollients in the skincare industry in terms of thermal/oxidation stability, composition and moisturizing properties. Oxidation stability of emollients was compared using Rancimat and pressurized differential scanning calorimetry (PDSC) techniques. Fatty acid composition of each oil was analysed using proton nuclear magnetic resonance (¹ H-NMR) and gas chromatography (GC) techniques to correlate unsaturation level of each oil to its oxidation stability. We also conducted an in vivo moisturizing study in which skin hydration level of human subjects was compared before and after application of emollient up to 24 h.

RESULTS

Results showed that Bio-Based Algae Oil was the most stable emollient in thermal and oxidation stability studies given its low unsaturation and high anti-oxidant content determined by ¹ H-NMR and GC techniques. It also provided the highest skin hydration level when applied on skin demonstrating its efficacy as a moisturizing emollient in cosmetic formulations.

CONCLUSIONS

Compositional analysis of Bio-Based Algae revealed that it is a triglyceride containing primarily three monounsaturated oleic acid chains with very low polyunsaturated fatty acid content resulting in high oxidation stability and consequently prolonged shelf-life. Given its sustainability, high oxidation stability and skin health benefits such as moisturization demonstrated during an in vivo study, we envision to utilize Bio-Based Algae Oil in many cosmetic formulations across skincare, suncare and bath and shower markets.

P845 Deep vein thrombosis, pulmonary embolism and patent foramen ovale: a lethal mix

A 50-year-old woman without remarkable medical history was admitted at the Emergency Department for acute dyspnoea. The patient had been recently submitted to C5-C6 microdiscectomy. She was tachypneic and oxygen saturation was 88%. CT angiography showed bilateral pulmonary embolism (PE) (Figure 1A, yellow arrowheads) with signs of right ventricle overload. Bilateral deep vein thrombosis was also confirmed. The patient was admitted at the Intensive Care Unit, clinically stable. Few hours later, she presented sudden hemodynamic and respiratory deterioration, requiring invasive mechanical ventilation and vasopressors. Due to recent cervical surgery, systemic fibrinolysis was ruled out. Decision for percutaneous thrombectomy and inferior vena cava filter placement was made. Nevertheless, percutaneous thrombectomy was unsuccessful due to the impossibility to catheterize pulmonary artery. Contrast injection demonstrated that the guiding catheter was located in the left atrium (Figure 1B), suggesting a patent foramen ovale (PFO). Transoesophageal echocardiogram confirmed the presence of a 5x6 mm PFO with right-to-left shunt (Figures 1C – yellow arrows, and 1D). In addition, a 4 cm mobile mass attached to the aortic valve and protruding throughout the left ventricle outflow tract was visualized, suggesting paradoxical embolism (Figure 1E – white arrows). Accordingly, open surgical approach with pulmonary thrombectomy, PFO closure and removal of the left-sided thrombus was decided. Unfortunately, despite careful cannulation, thrombus was not found when aortic valve was inspected. Worst suspicions were confirmed, when the patient presented non-reactive mydriatic pupils. A brain CT showed signs of an extensive bihemisferic ischemic stroke (Figure 1F) presumably related to cerebral embolization of aortic thrombus. The patient finally died. Autopsy study was not consented.

PFO has been associated with paradoxical embolisms and risk of stroke in PE. This case strikingly illustrates that treatment of these patients may be challenging in spite of an adequate diagnosis and management.

Abstract P845 Figure.

1095 Effective image-guided medical management in effusive constrictive pericarditis

A 59 year old man was admited to hospitalization for persistent chest pain related to acute pericarditis. Within the admision tests, a transthoracic echography was performed, showing a moderate pericardial effusion with ventricular septal bounce and significant respiratory variations in mitral and tricuspid inflows, all of it consistent with effusive-constrictive pericarditis (Panel A). Anti-inflammatory treatment with ibuprofen and colchicine was started.

During the first 48 hours of admission there was a clinical and hemodinamic worsening in the patient’s condition that forced the performance of a pericardial window, obtaining a very little quantity of dense pericardial fluid. Looking for a more accurate study of the pericardium, a cardiovascular magnetic resonance (CMR) was performed, revealing a thick heterogeneous pericardial effusion (Panel B) and a significant late gadolinium enhancement of both pericardial layers (Panel C). All these findings where consistent with an effusive constrictive pericarditis with persistent inflammatory activity despite high doses of conventional inflammatory treatment. Furthermore, the growth of Propionibacterium acnes in the pericardial fluid disclosed the etiology of this condition.

Medical treatment was enhanced with high doses of intravenous corticosteroid, ceftriaxone and doxycycline. During the following days, the patient showed an excellent response achieving the complete clinical and echocardiographic relief of constrictive signs (Panel D).

Effusive constrictive pericarditis is characterized by the presence of pericardial effusion and constriction secondary to an inflammatory process of the pericardium. Pericardiectomy might be necessary in case of failure of medical treatment, a very common scenario in this kind of .pericarditis.

Our case is remarkable because it demonstrates the value of CMR to detect persistent inflammation of pericardium despite high doses of conventional medical treatment for pericaricarditis guiding the successful escalation to intravenous corticosteroid and avoiding the risk of an unnecessary cardiac surgery.

Abstract 1095 Figure.

Evaluation of VIDAS® Listeria species Xpress (LSX) Immunoassay Method for the Detection of Listeria species in Foods: Collaborative Study

In a multilaboratory study, the effectiveness of an alternative method for rapid screening of Listeria species compared to traditional reference methods was demonstrated in a variety of food products. A collaborative study was conducted to compare the VIDAS® Listeria species Xpress (LSX) method and the standard cultural methods for the detection of Listeria species in foods. Six food types were tested: vanilla ice cream, cheddar cheese, raw ground beef, frozen green beans, deli turkey, and cooked shrimp. Each food, inoculated with a different Listeria strain at two levels and uninoculated test portions, was analyzed by each method. A total of 15 laboratories representing government and industry participated. In this study 1134 tests were analyzed in the statistical analysis. There were 490 positives by the VIDAS LSX method using the sample boiling step, 483 positives by the VIDAS LSX method using the Heat and Go system, and 439 positives by the standard culture methods. Overall, the Chi-square result for the VIDAS LSX method with boiling for all foods was 7.25, indicating a significant statistical difference between the VIDAS method and the standard methods at the 5% confidence. For the VIDAS LSX method with the Heat and Go system, the Chi-square result for all foods was 5.37, indicating a significant statistical difference between the VIDAS LSX assay with the Heat and Go system and the standard methods at the 5% level of significance. In both cases, the VIDAS method was more sensitive than the standard methods. The LSX method detects Listeria species in foods with negative or presumptive positive results in a minimum of 30 h compared to at least 5 days for the cultural methods. Based on the results of this collaborative study, it is recommended that the VIDAS LSX method be adopted as an AOAC Official MethodSM for the detection of Listeria species in dairy products, vegetables, seafood, raw meats and poultry, and processed meats and poultry.

Enumeration of Total Coliforms and E. coli in Foods by the SimPlate® Coliform and E. coli Color Indicator Method and Conventional Culture Methods: Collaborative Study

The relative effectiveness of the SimPlate® Coliform and E. coli Color Indicator (CEc-CI) method was compared to the AOAC 3-tube Most Probable Number (MPN) methods for enumerating and confirming coliforms and Escherichia coli in foods (966.23 and 966.24). In this study, test portions were prepared and analyzed according to the conditions stated in both the AOAC methods and SimPlate directions for use. Six food types were artificially contaminated with coliform bacteria and E. coli: frozen burritos, frozen broccoli, fluid pasteurized milk, whole almond nut meats, cheese, and powdered cake mix. Method comparisons were conducted. Overall, the SimPlate method demonstrated <0.3 log difference for total coliform and E. coli counts compared to the AOAC reference methods for the majority of food types and levels analyzed. In all cases, the repeatability and reproducibility of the SimPlate CEc-CI method were not different from those of the reference methods and in certain cases, were statistically better than those of the AOAC 3-tube MPN methods. These results indicate that the SimPlate CEc-CI method and the reference culture methods are comparable for enumeration of both total coliforms and E. coli in foods.

Post-exposure prophylaxis for HIV infection in sexual assault victims

OBJECTIVES

Sexual assault (SA) is recognized as a public health problem of epidemic proportions. Guidelines recommend the administration of post-exposure prophylaxis (PEP) after an SA. However, few data are available about the feasibility of this strategy, and this study was conducted to assess this.

METHODS

We conducted a retrospective, longitudinal, observational study in SA victims attending the Hospital Clinic in Barcelona from 2006 to 2015. A total of 1695 SA victims attended the emergency room (ER), of whom 883 met the PEP criteria. Five follow-up visits were scheduled at days 1, 10, 28, 90 and 180 in the out-patient clinic. The primary endpoint was PEP completion rate at day 28. Secondary endpoints were loss to follow-up, treatment discontinuation, occurrence of adverse events (AEs) and rate of seroconversion.

RESULTS

The median age of participants was 25 years [interquartile range (IQR) 21-33 years] and 93% were female. The median interval between exposure and presentation at the ER was 13 h (IQR 6-24 h). The level of risk was appreciable in 47% (n = 466) of individuals. Of 883 patients receiving PEP, 631 lived in Catalonia. In this group, the PEP completion rate at day 28 was 29% (n = 183). The follow-up rate was 63% (n = 400) and 38% (n = 241) at days 1 and 28, respectively. Treatment discontinuation was present in 58 (15%) of 400 patients who attended at least the day 1 visit, the main reason being AEs (n = 35; 60%). AEs were reported in 226 (56%) patients, and were mainly gastrointestinal (n = 196; 49%). Only 211 (33%) patients returned for HIV testing at day 90. A single seroconversion was observed in a men who have sex with men (MSM) patient at day 120.

CONCLUSIONS

Follow-up and compliance rates in SA victims were poor. In addition, > 50% of the patients experienced AEs, which were the main reason for PEP interruption. Strategies to increase follow-up testing and new better tolerated drug regimens must be investigated to address these issues.

Immunogenicity of sequential 13-valent conjugated and 23-valent unconjugated pneumococcal vaccines in a population of children with lupus

Pneumococcal vaccination is recommended as a quality indicator for management of children with systemic lupus erythematosus. Literature on the immunogenicity of pneumococcal vaccines (PCVs) in children is scant. We sought to prospectively evaluate via an observational study, the immunogenicity to sequential children with lupus. Out of a cohort of 26 patients, approximately 65% achieved > 70% vaccinated serotype antibody levels of > 1.3 mcg/dL following PCV13, and of 22 patients followed through PPSV23 vaccination, 59% achieved the same. Patients with rituximab exposure in the 6 months prior to a vaccination were more likely to not achieve protective serotype levels ( p < 0.01 for PCV13, trend p = 0.07 for PPSV23). Three of 22 patients with no apparent risk factors did not achieve protective serotype levels. Non-responders to PCV13 generally did not respond to PPSV23. Retrospective healthy controls achieved 100% protective levels in response to PPSV23 vaccination, with 95% of serotypes being > 1.3 mcg/dL. Thus, sequential 13- and 23-valent pneumococcal vaccines achieve protective status for approximately two thirds of pediatric lupus patients in our population. Lack of response to vaccine may be secondary to induced or inherent functional impairments in the patient.

Acceptability of self-sampling and human papillomavirus testing among non-attenders of cervical cancer screening programs in El Salvador

In a cross-sectional study carried out in El Salvador between February 2016 and July 2017, self-sampling and human papillomavirus (HPV) testing was found to be highly acceptable among 2019 women who had not attended a cervical cancer screening in at least 3 years. Within this population, HPV positivity rates differed according to age, marital status, number of children, and lifetime sexual partners. The proportion of women who tested HPV positive or who were diagnosed with cervical intraepithelial neoplasia grade 2 (CIN2) or more severe diagnoses (CIN2+) was similar to the general population of the area. Among the reasons for failing to participate in previous screening programs, non-attending women described logistic concerns, but also erroneous beliefs regarding HPV and cervical cancer, misconceptions regarding the screening procedure, discomfort with male providers, and confidentiality fears. The aim of this study was to identify opportunities and challenges that emerged from the use of self-sampling and HPV testing as part of a public cervical cancer control effort in a low-resource setting.

Observational multi-centre, prospective study to characterize novel pathogen-and host-related factors in hospitalized patients with lower respiratory tract infections and/or sepsis - the "TAILORED-Treatment" study

Background

The emergence and spread of antibiotic resistant micro-organisms is a global concern, which is largely attributable to inaccurate prescribing of antibiotics to patients presenting with non-bacterial infections. The use of ‘omics’ technologies for discovery of novel infection related biomarkers combined with novel treatment algorithms offers possibilities for rapidly distinguishing between bacterial and viral infections. This distinction can be particularly important for patients suffering from lower respiratory tract infections (LRTI) and/or sepsis as they represent a significant burden to healthcare systems. Here we present the study details of the TAILORED-Treatment study, an observational, prospective, multi-centre study aiming to generate a multi-parametric model, combining host and pathogen data, for distinguishing between bacterial and viral aetiologies in children and adults with LRTI and/or sepsis.

Methods

A total number of 1200 paediatric and adult patients aged 1 month and older with LRTI and/or sepsis or a non-infectious disease are recruited from Emergency Departments and hospital wards of seven Dutch and Israeli medical centres. A panel of three experienced physicians adjudicate a reference standard diagnosis for all patients (i.e., bacterial or viral infection) using all available clinical and laboratory information, including a 28-day follow-up assessment. Nasal swabs and blood samples are collected for multi-omics investigations including host RNA and protein biomarkers, nasal microbiota profiling, host genomic profiling and bacterial proteomics. Simplified data is entered into a custom-built database in order to develop a multi-parametric model and diagnostic tools for differentiating between bacterial and viral infections. The predictions from the model will be compared with the consensus diagnosis in order to determine its accuracy.

Discussion

The TAILORED-Treatment study will provide new insights into the interplay between the host and micro-organisms. New host- or pathogen-related biomarkers will be used to generate a multi-parametric model for distinguishing between bacterial and viral infections. This model will be helpful to better guide antimicrobial therapy for patients with LRTI and sepsis. This study has the potential to improve patient care, reduce unnecessary antibiotic prescribing and will contribute positively to institutional, national and international healthcare economics.

Trial Registration

NCT02025699. Registration Date: January, 1, 2014.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3300-9) contains supplementary material, which is available to authorized users.

Trees, fungi and bacteria: tripartite metatranscriptomics of a root microbiome responding to soil contamination

BACKGROUND

One method for rejuvenating land polluted with anthropogenic contaminants is through phytoremediation, the reclamation of land through the cultivation of specific crops. The capacity for phytoremediation crops, such as Salix spp., to tolerate and even flourish in contaminated soils relies on a highly complex and predominantly cryptic interacting community of microbial life.

METHODS

Here, Illumina HiSeq 2500 sequencing and de novo transcriptome assembly were used to observe gene expression in washed Salix purpurea cv. 'Fish Creek' roots from trees pot grown in petroleum hydrocarbon-contaminated or non-contaminated soil. All 189,849 assembled contigs were annotated without a priori assumption as to sequence origin and differential expression was assessed.

RESULTS

The 839 contigs differentially expressed (DE) and annotated from S. purpurea revealed substantial increases in transcripts encoding abiotic stress response equipment, such as glutathione S-transferases, in roots of contaminated trees as well as the hallmarks of fungal interaction, such as SWEET2 (Sugars Will Eventually Be Exported Transporter). A total of 8252 DE transcripts were fungal in origin, with contamination conditions resulting in a community shift from Ascomycota to Basidiomycota genera. In response to contamination, 1745 Basidiomycota transcripts increased in abundance (the majority uniquely expressed in contaminated soil) including major monosaccharide transporter MST1, primary cell wall and lamella CAZy enzymes, and an ectomycorrhiza-upregulated exo-β-1,3-glucanase (GH5). Additionally, 639 DE polycistronic transcripts from an uncharacterised Enterobacteriaceae species were uniformly in higher abundance in contamination conditions and comprised a wide spectrum of genes cryptic under laboratory conditions but considered putatively involved in eukaryotic interaction, biofilm formation and dioxygenase hydrocarbon degradation.

CONCLUSIONS

Fungal gene expression, representing the majority of contigs assembled, suggests out-competition of white rot Ascomycota genera (dominated by Pyronema), a sometimes ectomycorrhizal (ECM) Ascomycota (Tuber) and ECM Basidiomycota (Hebeloma) by a poorly characterised putative ECM Basidiomycota due to contamination. Root and fungal expression involved transcripts encoding carbohydrate/amino acid (C/N) dialogue whereas bacterial gene expression included the apparatus necessary for biofilm interaction and direct reduction of contamination stress, a potential bacterial currency for a role in tripartite mutualism. Unmistakable within the metatranscriptome is the degree to which the landscape of rhizospheric biology, particularly the important but predominantly uncharacterised fungal genetics, is yet to be discovered.

Hydroxychloroquine in the primary thrombosis prophylaxis of antiphospholipid antibody positive patients without systemic autoimmune disease

Objective The objective of this study was to determine the efficacy of hydroxychloroquine (HCQ) in the primary thrombosis prevention of antiphospholipid antibody (aPL)-positive patients with no other systemic autoimmune diseases. Methods Under the auspices of Antiphospholipid Syndrome Alliance for Clinical Trials and International Networking, a multicenter, international, randomized controlled trial (RCT) was initiated, in which persistently aPL-positive but thrombosis-free patients without systemic autoimmune diseases were randomized to receive HCQ or no treatment in addition to their standard regimen. The primary objective was the efficacy of HCQ in preventing the first thrombosis. The secondary objectives were the thrombosis incidence rate, and the effects of HCQ on aPL profile and mortality rate. Patients were risk-stratified based on antiplatelet agent use. The goal was to follow patients every 6 months for 5 years. Results We recruited 20 persistently aPL-positive patients (female: 19, mean age: 46.6 ± 9.9 years, and baseline antiplatelet medication: 14); 9/20 were randomized to HCQ. During the mean follow-up of 1.7 years, no patients developed thrombosis or a serious adverse event. The study was terminated early due to the low recruitment rate, exacerbated by the prolonged manufacturing shortage and significant price increase of HCQ in the United States. Conclusion Given that a small number of patients with a relatively short follow-up were enrolled in our RCT, and no patients developed thrombosis, we cannot accurately assess the effectiveness of HCQ for primary thrombosis prevention in persistently aPL-positive patients with no other systemic autoimmune diseases. Our experience suggests that conducting an international RCT, especially without pharmaceutical support, is an extremely challenging undertaking.

Does an interaction exist between ketamine hydrochloride and Becton Dickinson syringes?

Introduction

An international alert from Becton Dickinson (BD) has noted the possibility of interaction between several molecules and some syringes. The Centralized IntraVenous Additives Service of the institution was using 3 mL BD syringes to store ketamine HCl. This study evaluated the interaction between ketamine and these syringes.

Method

A batch of BD syringes produced in Europe and left in quarantine from the day of the international alert has been tested at 22, 29, 36, 43 and 50 days of storage at room temperature. At each time, the pH of the solutions was measured. The solutions were inspected visually and by microscope, and spectrophotometric measurements were performed. The concentrations were measured by a validated ultra-high-performance liquid chromatography-diode array detector.

Results

Neither physical change nor pH modification was observed during the study. According to a lower limit of the 95% unilateral CI on the mean >90% of the theoretical concentration, the solutions remain stable for at least 50 days.

Conclusion

In our study conditions, ketamine can be stored for at least 50 days without risk of sorption with syringes.

Genetic parameters and crossbreeding effects of fat deposition and fatty acid profiles in Iberian pig lines

The aim of this study was to estimate the genetic and environmental parameters and crossbreeding effects on fatty acid and fat traits in the Iberian pig. Our final goal is to explore target selection traits and define crossbreeding strategies. The phenotypes were obtained under intensive management from 470 animals in a diallelic experiment involving Retinto, Torbiscal, and Entrepelado lines. The data set was composed of backfat thickness at the fourth rib (BFT), intramuscular fat (IMF) in the longissimus thoracis (LT), and the fatty acid profile for IMF and subcutaneous fat (SCF) traits. Data were analyzed through a Bayesian bivariate animal model by using a reparameterization of Dickerson's model. The results obtained showed an important genetic determinism for all traits analyzed with heritability ranging from 0.09 to 0.67. The common environment litter effect also had an important effect on IMF (0.34) and its fatty acid composition (0.06-0.53) at slaughter. The additive genetic correlation between BFT and IMF (additive genetic correlation [] = 0.31) suggested that it would be possible to improve lean growth independent of the IMF with an appropriate selection index. Furthermore, the high additive genetic correlation ( = 0.68) found between MUFA tissues would seem to indicate that either the LT or SCF could be used as the reference tissue for MUFA selection. The relevance of the crossbreeding parameters varied according to the traits analyzed. Backfat thickness at the fourth rib and the fatty acid profile of the IMF showed relevant differences between crosses, mostly due to line additive genetic effects associated with the Retinto line. On the contrary, those for IMF crosses were probably mainly attributable to heterosis effects. Particularly, heterosis effects were relevant for the Retinto and Entrepelado crosses (approximately 16% of the trait), which could be valuable for a crossbreeding system involving these lines.

Didactic Psychological Counselling ΠA Real Challenge

Questionnaires were issued to fourth year students and to psychologists in trainee posts who had taken part in the didactic psychological counselling course at the University of Lausanne in Switzerland. This article reviews the various challenges posed by this type of counselling in the university context little accustomed to addressing issues arising in professional practice. This qualitative evaluation shows that the students and trainee psychologists viewed training that combined a university course with practical experience in the future professional .eld as essential. The evaluation also con.rmed that the students believed the objectives and the corresponding teaching tools employed on the course to be relevant. The objectives are also in line with the ‘transdisciplinarity‘ approach proposed by the authors and supported by the CIRET-UNESCO report (1997) extolling the virtues of ‘the four pillars of a new kind of education: learning to know, learning to do, learning to live together with and learning to be‘. Understood in this context, the educational and clinical aims of our counselling course satisfy the new expectations of the university of tomorrow.

[Analysis of Conformational Features of Watson-Crick Duplex Fragments by Molecular Mechanics and Quantum Mechanics Methods]

It is generally accepted that the important characteristic features of the Watson-Crick duplex originate from the molecular structure of its subunits. However, it still remains to elucidate what properties of each subunit are responsible for the significant characteristic features of the DNA structure. The computations of desoxydinucleoside monophosphates complexes with Na-ions using density functional theory revealed a pivotal role of DNA conformational properties of single-chain minimal fragments in the development of unique features of the Watson-Crick duplex. We found that directionality of the sugar-phosphate backbone and the preferable ranges of its torsion angles, combined with the difference between purines and pyrimidines. in ring bases, define the dependence of three-dimensional structure of the Watson-Crick duplex on nucleotide base sequence. In this work, we extended these density functional theory computations to the minimal' fragments of DNA duplex, complementary desoxydinucleoside monophosphates complexes with Na-ions. Using several computational methods and various functionals, we performed a search for energy minima of BI-conformation for complementary desoxydinucleoside monophosphates complexes with different nucleoside sequences. Two sequences are optimized using ab initio method at the MP2/6-31++G** level of theory. The analysis of torsion angles, sugar ring puckering and mutual base positions of optimized structures demonstrates that the conformational characteristic features of complementary desoxydinucleoside monophosphates complexes with Na-ions remain within BI ranges and become closer to the corresponding characteristic features of the Watson-Crick duplex crystals. Qualitatively, the main characteristic features of each studied complementary desoxydinucleoside monophosphates complex remain invariant when different computational methods are used, although the quantitative values of some conformational parameters could vary lying within the limits typical for the corresponding family. We observe that popular functionals in density functional theory calculations lead to the overestimated distances between base pairs, while MP2 computations and the newer complex functionals produce the structures that have too close atom-atom contacts. A detailed study of some complementary desoxydinucleoside monophosphate complexes with Na-ions highlights the existence of several energy minima corresponding to BI-conformations, in other words, the complexity of the relief pattern of the potential energy surface of complementary desoxydinucleoside monophosphate complexes. This accounts for variability of conformational parameters of duplex fragments with the same base sequence. Popular molecular mechanics force fields AMBER and CHARMM reproduce most of the conformational characteristics of desoxydinucleoside monophosphates and their complementary complexes with Na-ions but fail to reproduce some details of the dependence of the Watson-Crick duplex conformation on the nucleotide sequence.

Successful treatment of neonatal atypical hemolytic uremic syndrome with C5 monoclonal antibody

Hemolytic uremic syndrome (HUS) is rare in neonates. We report the case of atypical HUS (aHUS) revealed by neonatal seizures. This 18-day-old baby presented with repeated clonus of the left arm and eye deviation. Four days earlier, she had suffered from gastroenteritis (non-bloody diarrhea and vomiting without fever). Her work-up revealed hemolytic anemia (120 g/L), thrombocytopenia (78 g/L), and impaired renal function (serum creatinine=102 μmol/L) compatible with the diagnosis of HUS. Levels of C3 and C4 in the serum were normal. Shiga-toxin in the stools as well as the IgM and IgG against Escherichia coli O157 were negative. ADAMTS 13 deficiency, inborn error of the cobalamin pathway, deficiency in the H and I protein, and factor H antibodies were excluded and we concluded in aHUS. Genetic screening of the alternative complement pathway was normal. Cerebral magnetic resonance imaging performed after 24 h and 1 week showed restricted diffusion areas with periventricular white matter ischemic-hemorrhagic lesions. Extensive infectious work-up was negative. Upon admission the baby received antiepileptic drugs and 2 days later C5 monoclonal antibody (eculizumab) and two transfusions of packed erythrocytes because the hemoglobin value had dropped to 55 g/L. The platelet value was minimal at 30 g/L. Renal function normalized in 48 h without dialysis and neurological examination was normal in 1 week. She was discharged from the hospital at day 10 with eculizumab perfusions (300 mg) planned every 3 weeks. After 24 months, she was relapse-free and seizure-free, with a normal neurological examination.

Viscoelastic measurements of platelet function, not fibrinogen function, predicts sensitivity to tissue-type plasminogen activator in trauma patients

BACKGROUND

Systemic hyperfibrinolysis is a lethal phenotype of trauma-induced coagulopathy. Its pathogenesis is poorly understood. Recent studies have support a central role of platelets in hemostasis and in fibrinolysis regulation, implying that platelet impairment is integral to the development of postinjury systemic hyperfibrinolysis.

OBJECTIVE

The objective of this study was to identify if platelet function is associated with blood clot sensitivity to fibrinolysis. We hypothesize that platelet impairment of the ADP pathway correlates with fibrinolysis sensitivity in trauma patients.

METHODS

A prospective observational study of patients meeting the criteria for the highest level of activation at an urban trauma center was performed. Viscoelastic parameters associated with platelet function (maximum amplitude [MA]) were measured with native thrombelastography (TEG), and TEG platelet mapping of the ADP pathway (ADP-MA). The contribution of fibrinogen to clotting was measured with TEG (angle) and the TEG functional fibrinogen (FF) assay (FF-MA). Another TEG assay containing tissue-type plasminogen activator (t-PA) (75 ng mL(-1) ) was used to assess clot sensitivity to an exogenous fibrinolytic stimulus by use of the TEG lysis at 30 min (LY30) variable. Multivariate linear regression was used to identify which TEG variable correlated with t-PA-LY30 (quantification of fibrinolysis sensitivity).

RESULTS

Fifty-eight trauma patients were included in the analysis, with a median injury severity score of 17 and a base deficit of 6 mEq L(-1) . TEG parameters that significantly predicted t-PA-LY30 were related to platelet function (ADP-MA, P = 0.001; MA, P < 0.001) but not to fibrinogen (FF-MA, P = 0.773; angle, P = 0.083). Clinical predictors of platelet ADP impairment included calcium level (P = 0.001), base deficit (P = 0.001), and injury severity (P = 0.001).

RESULTS AND CONCLUSIONS

Platelet impairment of the ADP pathway is associated with increased sensitivity to t-PA. ADP pathway inhibition in platelets may be an early step in the pathogenesis of systemic hyperfibrinolysis.