742 research outputs found

    A risk prediction model for the assessment and triage of women with hypertensive disorders of pregnancy in low-resourced settings: the miniPIERS (Pre-eclampsia Integrated Estimate of RiSk) multi-country prospective cohort study.

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    BACKGROUND: Pre-eclampsia/eclampsia are leading causes of maternal mortality and morbidity, particularly in low- and middle- income countries (LMICs). We developed the miniPIERS risk prediction model to provide a simple, evidence-based tool to identify pregnant women in LMICs at increased risk of death or major hypertensive-related complications. METHODS AND FINDINGS: From 1 July 2008 to 31 March 2012, in five LMICs, data were collected prospectively on 2,081 women with any hypertensive disorder of pregnancy admitted to a participating centre. Candidate predictors collected within 24 hours of admission were entered into a step-wise backward elimination logistic regression model to predict a composite adverse maternal outcome within 48 hours of admission. Model internal validation was accomplished by bootstrapping and external validation was completed using data from 1,300 women in the Pre-eclampsia Integrated Estimate of RiSk (fullPIERS) dataset. Predictive performance was assessed for calibration, discrimination, and stratification capacity. The final miniPIERS model included: parity (nulliparous versus multiparous); gestational age on admission; headache/visual disturbances; chest pain/dyspnoea; vaginal bleeding with abdominal pain; systolic blood pressure; and dipstick proteinuria. The miniPIERS model was well-calibrated and had an area under the receiver operating characteristic curve (AUC ROC) of 0.768 (95% CI 0.735-0.801) with an average optimism of 0.037. External validation AUC ROC was 0.713 (95% CI 0.658-0.768). A predicted probability ≥25% to define a positive test classified women with 85.5% accuracy. Limitations of this study include the composite outcome and the broad inclusion criteria of any hypertensive disorder of pregnancy. This broad approach was used to optimize model generalizability. CONCLUSIONS: The miniPIERS model shows reasonable ability to identify women at increased risk of adverse maternal outcomes associated with the hypertensive disorders of pregnancy. It could be used in LMICs to identify women who would benefit most from interventions such as magnesium sulphate, antihypertensives, or transportation to a higher level of care

    Mechanosensitive Enteric Neurons in the Myenteric Plexus of the Mouse Intestine

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    BACKGROUND: Within the gut the autonomous enteric nervous system (ENS) is able to sense mechanical stimuli and to trigger gut reflex behaviour. We previously proposed a novel sensory circuit in the ENS which consists of multifunctional rapidly adapting mechanosensitive enteric neurons (RAMEN) in the guinea pig. The aim of this study was to validate this concept by studying its applicability to other species or gut regions. METHODOLOGY/PRINCIPAL FINDINGS: We deformed myenteric ganglia in the mouse small and large intestine and recorded spike discharge using voltage sensitive dye imaging. We also analysed expression of markers hitherto proposed to label mouse sensory myenteric neurons in the ileum (NF145kD) or colon (calretinin). RAMEN constituted 22% and 15% of myenteric neurons per ganglion in the ileum and colon, respectively. They encoded dynamic rather than sustained deformation. In the colon, 7% of mechanosensitive neurons fired throughout the sustained deformation, a behaviour typical for slowly adapting echanosensitive neurons (SAMEN). RAMEN and SAMEN responded directly to mechanical deformation as their response remained unchanged after synaptic blockade in low Ca(++)/high Mg(++). Activity levels of RAMEN increased with the degree of ganglion deformation. Recruitment of more RAMEN with stronger stimuli may suggest low and high threshold RAMEN. The majority of RAMEN were cholinergic but most lacked expression of NF145kD or calretinin. CONCLUSIONS/SIGNIFICANCE: We showed for the first time that fundamental properties of mechanosensitive enteric neurons, such as firing pattern, encoding of dynamic deformation, cholinergic phenotype and their proportion, are conserved across species and regions. We conclude that RAMEN are important for mechanotransduction in the ENS. They directly encode dynamic changes in force as their firing frequency is proportional to the degree of deformation of the ganglion they reside in. The additional existence of SAMEN in the colon is likely an adaptation to colonic motor patterns which consist of phasic and tonic contractions

    Uncovering the Dynamics of Cardiac Systems Using Stochastic Pacing and Frequency Domain Analyses

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    Alternans of cardiac action potential duration (APD) is a well-known arrhythmogenic mechanism which results from dynamical instabilities. The propensity to alternans is classically investigated by examining APD restitution and by deriving APD restitution slopes as predictive markers. However, experiments have shown that such markers are not always accurate for the prediction of alternans. Using a mathematical ventricular cell model known to exhibit unstable dynamics of both membrane potential and Ca2+ cycling, we demonstrate that an accurate marker can be obtained by pacing at cycle lengths (CLs) varying randomly around a basic CL (BCL) and by evaluating the transfer function between the time series of CLs and APDs using an autoregressive-moving-average (ARMA) model. The first pole of this transfer function corresponds to the eigenvalue (λalt) of the dominant eigenmode of the cardiac system, which predicts that alternans occurs when λalt≤−1. For different BCLs, control values of λalt were obtained using eigenmode analysis and compared to the first pole of the transfer function estimated using ARMA model fitting in simulations of random pacing protocols. In all versions of the cell model, this pole provided an accurate estimation of λalt. Furthermore, during slow ramp decreases of BCL or simulated drug application, this approach predicted the onset of alternans by extrapolating the time course of the estimated λalt. In conclusion, stochastic pacing and ARMA model identification represents a novel approach to predict alternans without making any assumptions about its ionic mechanisms. It should therefore be applicable experimentally for any type of myocardial cell

    Alterations of hemostatic parameters in the early development of allogeneic hematopoietic stem cell transplantation-related complications

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    Thrombotic events are common and potentially fatal complications in patients receiving hematopoietic stem cell transplantation (HSCT). Early diagnosis is crucial but remains controversial. In this study, we investigated the early alterations of hemostatic parameters in allogeneic HSCT recipients and determined their potential diagnostic values in transplantation-related thrombotic complications and other post-HSCT events. Results from 107 patients with allogeneic HSCT showed higher levels of plasma plasminogen activator inhibitor-1 (PAI-1), fibrinogen, and tissue-plasminogen activator (t-PA) and a lower level of plasma protein C after transplantation. No change was found for prothrombin time, antithrombin III, d-dimer, and activated partial thromboplastin time following HSCT. Transplantation-related complications (TRCs) in HSCT patients were defined as thrombotic (n = 8), acute graft-versus-host disease (aGVHD, n = 45), and infectious (n = 38). All patients with TRCs, especially the patients with thrombotic complications, presented significant increases in the mean and maximum levels of PAI-1 during the observation period. Similarly, a high maximum t-PA level was found in the thrombotic group. In contrast, apparent lower levels of mean and minimum protein C were observed in the TRC patients, especially in the aGVHD group. Therefore, the hemostatic imbalance in the early phase of HSCT, reflecting prothrombotic state and endothelial injury due to the conditioning therapy or TRCs, might be useful in the differential diagnosis of the thrombotic complication from other TRCs

    Ulk4 regulates GABAergic signaling and anxiety-related behavior

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    Excitation/inhibition imbalance has been proposed as a fundamental mechanism in the pathogenesis of neuropsychiatric and neurodevelopmental disorders, in which copy number variations of the Unc-51 like kinase 4 (ULK4) gene encoding a putative Serine/Threonine kinase have been reported in approximately 1/1000 of patients suffering pleiotropic clinical conditions of schizophrenia, depression, autistic spectrum disorder (ASD), developmental delay, language delay, intellectual disability, or behavioral disorder. The current study characterized behavior of heterozygous Ulk4(+/tm1a) mice, demonstrating that Ulk4(+/tm1a) mice displayed no schizophrenia-like behavior in acoustic startle reactivity and prepulse inhibition tests or depressive-like behavior in the Porsolt swim or tail suspension tests. However, Ulk4(+/tm1a) mice exhibited an anxiety-like behavioral phenotype in several tests. Previously identified hypo-anxious (Atp1a2, Ptn, and Mdk) and hyper-anxious (Gria1, Syngap1, and Npy2r) genes were found to be dysregulated accordingly in Ulk4 mutants. Ulk4 was found to be expressed in GABAergic neurons and the Gad67⁺ interneurons were significantly reduced in the hippocampus and basolateral amygdala of Ulk4(+/tm1a) mice. Transcriptome analyses revealed a marked reduction of GABAergic neuronal subtypes, including Pvalb, Sst, Cck, Npy, and Nos3, as well as significant upregulation of GABA receptors, including Gabra1, Gabra3, Gabra4, Gabra5, and Gabrb3. This is the first evidence that Ulk4 plays a major role in regulating GABAergic signaling and anxiety-like behavior, which may have implications for the development of novel anxiolytic treatments

    Biotransformation of lanthanum by Aspergillus niger

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    Lanthanum is an important rare earth element and has many applications in modern electronics and catalyst manufacturing. However, there exist several obstacles in the recovery and cycling of this element due to a low average grade in exploitable deposits and low recovery rates by energy-intensive extraction procedures. In this work, a novel method to transform and recover La has been proposed using the geoactive properties of Aspergillus niger. La-containing crystals were formed and collected after A. niger was grown on Czapek-Dox agar medium amended with LaCl 3. Energy-dispersive X-ray analysis (EDXA) showed the crystals contained C, O, and La; scanning electron microscopy revealed that the crystals were of a tabular structure with terraced surfaces. X-ray diffraction identified the mineral phase of the sample as La 2(C 2O 4) 3·10H 2O. Thermogravimetric analysis transformed the oxalate crystals into La 2O 3 with the kinetics of thermal decomposition corresponding well with theoretical calculations. Geochemical modelling further confirmed that the crystals were lanthanum decahydrate and identified optimal conditions for their precipitation. To quantify crystal production, biomass-free fungal culture supernatants were used to precipitate La. The results showed that the precipitated lanthanum decahydrate achieved optimal yields when the concentration of La was above 15 mM and that 100% La was removed from the system at 5 mM La. Our findings provide a new aspect in the biotransformation and biorecovery of rare earth elements from solution using biomass-free fungal culture systems. </p

    Treg Depletion Inhibits Efficacy of Cancer Immunotherapy: Implications for Clinical Trials

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    Regulatory T lymphocytes (Treg) infiltrate human glioblastoma (GBM); are involved in tumor progression and correlate with tumor grade. Transient elimination of Tregs using CD25 depleting antibodies (PC61) has been found to mediate GBM regression in preclinical models of brain tumors. Clinical trials that combine Treg depletion with tumor vaccination are underway to determine whether transient Treg depletion can enhance anti-tumor immune responses and improve long term survival in cancer patients.Using a syngeneic intracrabial glioblastoma (GBM) mouse model we show that systemic depletion of Tregs 15 days after tumor implantation using PC61 resulted in a decrease in Tregs present in tumors, draining lymph nodes and spleen and improved long-term survival (50% of mice survived >150 days). No improvement in survival was observed when Tregs were depleted 24 days after tumor implantation, suggesting that tumor burden is an important factor for determining efficacy of Treg depletion in clinical trials. In a T cell dependent model of brain tumor regression elicited by intratumoral delivery of adenoviral vectors (Ad) expressing Fms-like Tyrosine Kinase 3 ligand (Flt3L) and Herpes Simplex Type 1-Thymidine Kinase (TK) with ganciclovir (GCV), we demonstrate that administration of PC61 24 days after tumor implantation (7 days after treatment) inhibited T cell dependent tumor regression and long term survival. Further, depletion with PC61 completely inhibited clonal expansion of tumor antigen-specific T lymphocytes in response to the treatment.Our data demonstrate for the first time, that although Treg depletion inhibits the progression/eliminates GBM tumors, its efficacy is dependent on tumor burden. We conclude that this approach will be useful in a setting of minimal residual disease. Further, we also demonstrate that Treg depletion, using PC61 in combination with immunotherapy, inhibits clonal expansion of tumor antigen-specific T cells, suggesting that new, more specific targets to block Tregs will be necessary when used in combination with therapies that activate anti-tumor immunity

    A novel treatment of cystic fibrosis acting on-target:cysteamine plus epigallocatechin gallate for the autophagy-dependent rescue of class II-mutated CFTR

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    We previously reported that the combination of two safe proteostasis regulators, cysteamine and epigallocatechin gallate (EGCG), can be used to improve deficient expression of the cystic fibrosis transmembrane conductance regulator (CFTR) in patients homozygous for the CFTR Phe508del mutation. Here we provide the proof-of-concept that this combination treatment restored CFTR function and reduced lung inflammation (P<0.001) in Phe508del/Phe508del or Phe508del/null-Cftr (but not in Cftr-null mice), provided that such mice were autophagy-competent. Primary nasal cells from patients bearing different class II CFTR mutations, either in homozygous or compound heterozygous form, responded to the treatment in vitro. We assessed individual responses to cysteamine plus EGCG in a single-centre, open-label phase-2 trial. The combination treatment decreased sweat chloride from baseline, increased both CFTR protein and function in nasal cells, restored autophagy in such cells, decreased CXCL8 and TNF-α in the sputum, and tended to improve respiratory function. These positive effects were particularly strong in patients carrying Phe508del CFTR mutations in homozygosity or heterozygosity. However, a fraction of patients bearing other CFTR mutations failed to respond to therapy. Importantly, the same patients whose primary nasal brushed cells did not respond to cysteamine plus EGCG in vitro also exhibited deficient therapeutic responses in vivo. Altogether, these results suggest that the combination treatment of cysteamine plus EGCG acts ‘on-target' because it can only rescue CFTR function when autophagy is functional (in mice) and improves CFTR function when a rescuable protein is expressed (in mice and men). These results should spur the further clinical development of the combination treatment

    Deep Sequencing of Human Nuclear and Cytoplasmic Small RNAs Reveals an Unexpectedly Complex Subcellular Distribution of miRNAs and tRNA 3′ Trailers

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    MicroRNAs (miRNAs) are ∼22-nt small non-coding regulatory RNAs that have generally been considered to regulate gene expression at the post-transcriptional level in the cytoplasm. However, recent studies have reported that some miRNAs localize to and function in the nucleus.To determine the number of miRNAs localized to the nucleus, we systematically investigated the subcellular distribution of small RNAs (sRNAs) by independent deep sequencing sequenced of the nuclear and cytoplasmic pools of 18- to 30-nucleotide sRNAs from human cells. We identified 339 nuclear and 324 cytoplasmic known miRNAs, 300 of which overlap, suggesting that the majority of miRNAs are imported into the nucleus. With the exception of a few miRNAs evidently enriched in the nuclear pool, such as the mir-29b, the ratio of miRNA abundances in the nuclear fraction versus in the cytoplasmic fraction vary to some extent. Moreover, our results revealed that a large number of tRNA 3′trailers are exported from the nucleus and accumulate in the cytoplasm. These tRNA 3′ trailers accumulate in a variety of cell types, implying that the biogenesis of tRNA 3′ trailers is conserved and that they have a potential functional role in vertebrate cells.Our results provide the first comprehensive view of the subcellular distribution of diverse sRNAs and new insights into the roles of miRNAs and tRNA 3′ trailers in the cell
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