Extracellular vesicles from amniotic fluid, milk, saliva, and urine expose complexes of tissue factor and activated factor VII

Background Tissue factor (TF) is expressed in the adventitia of the vessel wall and on extracellular vesicles (EVs) in body fluids. TF and activated coagulation factor (F) VII(a) together form the so-called extrinsic tenase complex, which initiates coagulation. Aim We investigated whether EVs in amniotic fluid, milk, saliva, and urine expose functional extrinsic tenase complexes that can trigger coagulation. Methods Milk, saliva, and urine were collected from healthy breastfeeding women (n = 6), and amniotic fluid was collected from healthy women undergoing routine amniocentesis (n = 7). EVs were isolated from body fluids by size exclusion chromatography (SEC) and clotting experiments were performed in the presence and absence of antibodies against TF and FVIIa in normal plasma and in FVII-deficient plasma. The ability of body fluids to generate FXa also was determined. Results Amniotic fluid, milk, saliva, and urine triggered clotting of normal plasma and of FVII-deficient plasma, which was almost completely inhibited by an anti-FVII antibody and to a lesser extent by an anti-TF antibody. Fractionation of body fluids by SEC showed that only the fractions containing EVs triggered clotting in normal plasma and FVII-deficient plasma and generated FXa, which again was almost completely inhibited by an anti-FVII antibody and partially by an anti-TF antibody. Conclusion Here we show that EVs from amniotic fluid, milk, saliva, and urine expose complexes of TF and FVIIa (i.e., extrinsic tenase complexes) that directly activate FX. Based on our present findings we propose that these EVs from normal body fluids provide hemostatic protection

Patterns of Coupled Theta Activity in Amygdala-Hippocampal-Prefrontal Cortical Circuits during Fear Extinction

Signals related to fear memory and extinction are processed within brain pathways involving the lateral amygdala (LA) for formation of aversive stimulus associations, the CA1 area of the hippocampus for context-dependent modulation of these associations, and the infralimbic region of the medial prefrontal cortex (mPFC) for extinction processes. While many studies have addressed the contribution of each of these modules individually, little is known about their interactions and how they function as an integrated system. Here we show, by combining multiple site local field potential (LFP) and unit recordings in freely behaving mice in a fear conditioning paradigm, that theta oscillations may provide a means for temporally and functionally connecting these modules. Theta oscillations occurred with high specificity in the CA1-LA-mPFC network. Theta coupling increased between all areas during retrieval of conditioned fear, and declined during extinction learning. During extinction recall, theta coupling partly rebounded in LA-mPFC and CA1-mPFC, and remained at a low level in CA1-LA. Interfering with theta coupling through local electrical microstimulation in CA1-LA affected conditioned fear and extinction recall depending on theta phase. These results support the hypothesis that theta coupling provides a means for inter-areal coordination in conditioned behavioral responsiveness. More specifically, theta oscillations seem to contribute to a population code indicating conditioned stimuli during recall of fear memory before and after extinction

Context-Dependent Encoding of Fear and Extinction Memories in a Large-Scale Network Model of the Basal Amygdala

The basal nucleus of the amygdala (BA) is involved in the formation of context-dependent conditioned fear and extinction memories. To understand the underlying neural mechanisms we developed a large-scale neuron network model of the BA, composed of excitatory and inhibitory leaky-integrate-and-fire neurons. Excitatory BA neurons received conditioned stimulus (CS)-related input from the adjacent lateral nucleus (LA) and contextual input from the hippocampus or medial prefrontal cortex (mPFC). We implemented a plasticity mechanism according to which CS and contextual synapses were potentiated if CS and contextual inputs temporally coincided on the afferents of the excitatory neurons. Our simulations revealed a differential recruitment of two distinct subpopulations of BA neurons during conditioning and extinction, mimicking the activation of experimentally observed cell populations. We propose that these two subgroups encode contextual specificity of fear and extinction memories, respectively. Mutual competition between them, mediated by feedback inhibition and driven by contextual inputs, regulates the activity in the central amygdala (CEA) thereby controlling amygdala output and fear behavior. The model makes multiple testable predictions that may advance our understanding of fear and extinction memories

Aggressive nutrition in extremely low birth weight infants: impact on parenteral nutrition associated cholestasis and growth

Background Parenteral nutrition associated cholestasis (PNAC) is a frequently observed pathology in extremely low birth weight (ELBW) infants. Its pathogenesis is determined by the composition and duration of parenteral nutrition (PN) as well as the tolerance of enteral feeds (EF). “Aggressive” nutrition is increasingly used in ELBW infants to improve postnatal growth. Little is known about the effect of “aggressive” nutrition on the incidence of PNAC. We analyzed the influence of implementing an “aggressive” nutritional regimen on the incidence of PNAC and growth in a cohort of ELBW infants. Methods ELBW infants were nourished using a “conservative” (2005–6; n = 77) or “aggressive” (2007–9; n = 85) nutritional regimen that differed in the composition of PN after birth as well as the composition and timing of advancement of EFs. We analyzed the incidence of PNAC (conjugated bilirubin > 1.5 mg/dl (25 µmol/l)) corrected for confounders of cholestasis (i.e., NEC and/or gastrointestinal surgery, sepsis, birth weight, Z-score of birth weight, time on PN and male sex), growth until discharge (as the most important secondary outcome) and neonatal morbidities. Results The incidence of PNAC was significantly lower during the period of “aggressive” vs. “conservative “nutrition (27% vs. 46%, P < 0.05; adjusted OR 0.275 [0.116–0.651], P < 0.01). Body weight (+411g), head circumference (+1 cm) and length (+1 cm) at discharge were significantly higher. Extra-uterine growth failure (defined as a Z-score difference from birth to discharge lower than −1) was significantly reduced for body weight (85% vs. 35%), head circumference (77% vs. 45%) and length (85% vs. 65%) (P < 0.05). The body mass index (BMI) at discharge was significantly higher (11.1 vs. 12.4) using “aggressive” nutrition and growth became more proportionate with significantly less infants being discharged below the 10th BMI percentile (44% vs. 9%), while the percentage of infants discharged over the 90th BMI percentile (3% vs. 5%) did not significantly increase. Discussion “Aggressive” nutrition of ELBW infants was associated with a significant decrease of PNAC and marked improvement of postnatal growth

The Effect of an Osmotic Contrast Agent on Complete Meconium Evacuation in Preterm Infants

OBJECTIVE:To determine whether enteral application of the osmotic contrast agent Gastrografin accelerates complete meconium excretion and improves feeding tolerance in very low birth weight infants.METHODS:This study was a stratified, randomized, placebo-controlled trial in premature infants with a birth weight &amp;lt;1500 g and a gestational age &amp;lt;32 weeks who received 3 mL/kg Gastrografin diluted 1:3 with water within their first 24 hours of life, or placebo.RESULTS:Passage of last meconium occurred after a median of 7 days (95% confidence interval: 6–9 days, n = 39) in the intervention group and after 8 days (95% confidence interval: 7–10 days, n = 39) in the control group (P = .61); however, Gastrografin application was associated with a 7.5-day shorter time to full enteral feedings, a 24-day shorter stay in the NICU, and a 17-day reduction in the overall hospital stay in the intervention group compared with the control group. A numerically higher incidence of necrotizing enterocolitis (21%) was observed in the intervention group, however.CONCLUSIONS:Gastrografin application did not accelerate meconium evacuation, but the higher stool frequency during the first week of life had a beneficial effect on the time to full enteral feedings and later hospital stay; however, it may increase the necrotizing enterocolitis risk. Further investigations are needed with modified protocols, and the prophylactic use of Gastrografin cannot currently be recommended without further clinical trials.</jats:sec

A Mixed Lipid Emulsion for Prevention of Parenteral Nutrition Associated Cholestasis in Extremely Low Birth Weight Infants: A Randomized Clinical Trial

Objectives To examine whether a mixed lipid emulsion reduces the incidence of parenteral nutrition associated cholestasis (PNAC) in extremely low birth weight (ELBW, <1000 g) infants. Study design This double-blind randomized trial of 230 ELBW infants (June 2012-October 2015) was performed at a single level IV neonatal intensive care unit. Patients received either a mixed lipid emulsion composed of soybean oil, medium chain triglycerides, olive oil, and fish oil-(intervention) or a soybean oil-based lipid emulsion (control) for parenteral nutrition. The primary outcome measure was PNAC (conjugated bilirubin >1.5 mg/dL [25 µmol/L] at 2 consecutive measurements). The study was powered to detect a reduction of PNAC from 25% to 10%. Results Reasons for noneligibility of 274 infants screened were refusal to participate (n = 16), death (n = 10), withdrawal of treatment (n = 5), higher order multiples (n = 9), and parents not available for consent (n = 4). Intention to treat analysis was carried out in 223 infants (7 infants excluded after randomization). Parenteral nutrition associated cholestasis was 11 of 110 (10.1%) in the intervention and 18 of 113 (15.9%) in the control group (P = .20). Multivariable analyses showed no statistically significant difference in the intention to treat (aOR 0.428, 95% CI 0.155-1.187; P = .10) or per protocol population (aOR 0.457, 95% CI 0.155-1.347; P = .16). There was no statistically significant effect on any other neonatal morbidity. Conclusions The incidence of parenteral nutrition associated cholestasis was not significantly reduced using a mixed lipid emulsion in ELBW infants. Trial Registration ClinicalTrials.gov NCT01585935