1,450 research outputs found
MEF2C regulates outflow tract alignment and transcriptional control of Tdgf1
Congenital heart defects are the most common birth defects in
humans, and those that affect the proper alignment of the outflow
tracts and septation of the ventricles are a highly significant cause of
morbidity and mortality in infants. A late differentiating population of
cardiac progenitors, referred to as the anterior second heart field
(AHF), gives rise to the outflow tract and the majority of the right
ventricle and provides an embryological context for understanding
cardiac outflow tract alignment and membranous ventricular septal
defects. However, the transcriptional pathways controlling AHF
development and their roles in congenital heart defects remain
incompletely elucidated. Here, we inactivated the gene encoding the
transcription factor MEF2C in the AHF in mice. Loss of Mef2c function
in the AHF results in a spectrum of outflow tract alignment defects
ranging from overriding aorta to double-outlet right ventricle and
dextro-transposition of the great arteries. We identify Tdgf1, which
encodes a Nodal co-receptor (also known as Cripto), as a direct
transcriptional target of MEF2C in the outflow tract via an AHFrestricted
Tdgf1 enhancer. Importantly, both the MEF2C and TDGF1
genes are associated with congenital heart defects in humans. Thus,
these studies establish a direct transcriptional pathway between the
core cardiac transcription factor MEF2C and the human congenital
heart disease gene TDGF1. Moreover, we found a range of outflow
tract alignment defects resulting from a single genetic lesion,
supporting the idea that AHF-derived outflow tract alignment
defects may constitute an embryological spectrum rather than
distinct anomalies
Arabinoxyloglucan Oligosaccharides May Contribute to the Antiadhesive Properties of Porcine Urine after Cranberry Consumption
© 2019 As part of our continuing investigation for interesting biological activities of native medicinal plants, thirty-nine plants, obtained from diverse areas in Saudi Arabia and Yemen, were screened for insecticidal activity against yellow fever mosquito Aedes aegypti (L.). Out of the 57 organic extracts, Saussurea lappa, Ocimum tenuiflorum, Taraxacum officinale, Nigella sativa, and Hyssopus officinalis exhibited over 80% mortality against adult female Ae. aegypti at 5 Όg/mosquito. In the larvicidal bioassay, the petroleum ether extract of Aloe perryi flowers showed 100% mortality at 31.25 ppm against 1st instar Ae. aegypti larvae. The ethanol extract of Saussurea lappa roots was the second most active displaying 100% mortality at 125 and 62.5 ppm. Polar active extracts were processed using LC-MS/MS to identify bioactive compounds. The apolar A. perryi flower extract was analyzed by headspace SPME-GC/MS analysis. Careful examination of the mass spectra and detailed interpretation of the fragmentation pattern allowed the identification of various biologically active secondary metabolites. Some compounds such as caffeic and quinic acid and their glycosides were detected in most of the analyzed fractions. Additionally, luteolin, luteolin glucoside, luteolin glucuronide and diglucuronide were also identified as bioactive compounds in several HPLC fractions. The volatile ketone, 6-methyl-5-hepten-2-one was identified from A. perryi petroleum ether fraction as a major compound
The first endovascular repair of an acute type A dissection using an endograft designed for the ascending aorta
Endovascular repair has emerged as a potential alternative to emergency open surgical repair for type A dissection in selected patients, with isolated reports describing the results obtained with a range of devices designed originally for the descending aorta. We believe that we present the first reported repair of an acute ascending aortic dissection using an endovascular stent graft manufactured specifically for the ascending aorta
Titania-doped tantala/silica coatings for gravitational-wave detection
Reducing thermal noise from optical coatings is crucial to reaching the required sensitivity in next generation interferometric gravitational-wave detectors. Here we show that adding TiO2 to Ta2O5 in Ta2O5/SiO2 coatings reduces the internal friction and in addition present data confirming it reduces thermal noise. We also show that TiO2-doped Ta2O5/SiO2 coatings are close to satisfying the optical absorption requirements of second generation gravitational-wave detectors
Using a knowledge exchange event to assess study participantsâ attitudes to research in a rapidly evolving research context
Grant information: DJP, IJD and AMM are supported by Wellcome Trust Grant 104036. IJD, DJP, JPB and AMM, IB, EJK and SFW are supported by MRC Mental Health Data Pathfinder Grant MC_PC_17209. AMM and SML are supported by MRC Grant MC_PC_MR/R01910X/1. AMM is supported by MRC Grant MR/S035818/1. Theirworld Edinburgh Birth Cohort is funded by the charity Theirworld (www.theirworld.org), and is undertaken in the MRC Centre for Reproductive Health, which is funded by MRC Centre Grant (G1002033). CB and DJP are supported by Health Data Research UK, an initiative funded by UK Research and Innovation, Department of Health and Social Care (England) and the devolved administrations, and leading medical research charities.Peer reviewedPublisher PD
Group A streptococcus cell-associated pathogenic proteins as revealed by growth in hyaluronic acid enriched media.
Characterizing the diurnal patterns of errors in the prediction of evapotranspiration by several landâsurface models: An NACP analysis
Landâsurface models use different formulations of stomatal conductance and plant hydraulics, and it is unclear which type of model best matches the observed surfaceâatmosphere water flux. We use the North American Carbon Program data set of latent heat flux (LE) measurements from 25 sites and predictions from 9 models to evaluate models' ability to resolve subdaily dynamics of transpiration. Despite overall good forecast at the seasonal scale, the models have difficulty resolving the dynamics of intradaily hysteresis. The majority of models tend to underestimate LE in the prenoon hours and overestimate in the evening. We hypothesize that this is a result of unresolved afternoon stomatal closure due to hydrodynamic stresses. Although no model or stomata parameterization was consistently best or worst in terms of ability to predict LE, errors in modelâsimulated LE were consistently largest and most variable when soil moisture was moderate and vapor pressure deficit was moderate to limiting. Nearly all models demonstrate a tendency to underestimate the degree of maximum hysteresis which, across all sites studied, is most pronounced during moistureâlimited conditions. These diurnal error patterns are consistent with models' diminished ability to accurately simulate the natural hysteresis of transpiration. We propose that the lack of representation of plant hydrodynamics is, in part, responsible for these error patterns. Key Points Landâsurface models produce subdaily patterns of latent heat flux error Error patterns are characterized by the stomatal conductance formulation used Current models lack a mechanism to simulate hysteretic transpirationPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108341/1/jgrg20246.pd
Expression profiling of metalloproteinases and tissue inhibitors of metalloproteinases in normal and degenerate human achilles tendon
To profile the messenger RNA (mRNA) expression for the 23 known genes of matrix metalloproteinases (MMPs), 19 genes of ADAMTS, 4 genes of tissue inhibitors of metalloproteinases (TIMPs), and ADAM genes 8, 10, 12, and 17 in normal, painful, and ruptured Achilles tendons. Tendon samples were obtained from cadavers or from patients undergoing surgical procedures to treat chronic painful tendinopathy or ruptured tendon. Total RNA was extracted and mRNA expression was analyzed by quantitative real-time reverse transcriptionâpolymerase chain reaction, normalized to 18S ribosomal RNA. In comparing expression of all genes, the normal, painful, and ruptured Achilles tendon groups each had a distinct mRNA expression signature. Three mRNA were not detected and 14 showed no significant difference in expression levels between the groups. Statistically significant (P < 0.05) differences in mRNA expression, when adjusted for age, included lower levels of MMPs 3 and 10 and TIMP-3 and higher levels of ADAM-12 and MMP-23 in painful compared with normal tendons, and lower levels of MMPs 3 and 7 and TIMPs 2, 3, and 4 and higher levels of ADAMs 8 and 12, MMPs 1, 9, 19, and 25, and TIMP-1 in ruptured compared with normal tendons. The distinct mRNA profile of each tendon group suggests differences in extracellular proteolytic activity, which would affect the production and remodeling of the tendon extracellular matrix. Some proteolytic activities are implicated in the maintenance of normal tendon, while chronically painful tendons and ruptured tendons are shown to be distinct groups. These data will provide a foundation for further study of the role and activity of many of these enzymes that underlie the pathologic processes in the tendon
Lipopolysaccharide associated with ÎČ-2,6 fructan mediates TLR4-dependent immunomodulatory activity in vitro
Levan, a ÎČ-2,6 fructofuranose polymer produced by microbial species, has been reported for its immunomodulatory properties via interaction with toll-like receptor 4 (TLR4) which recognises lipopolysaccharide (LPS). However, the molecular mechanisms underlying these interactions remain elusive. Here, we investigated the immunomodulatory properties of levan using thoroughly-purified and characterised samples from Erwinia herbicola and other sources. E. herbicola levan was purified by gel-permeation chromatography and LPS was removed from the levan following a novel alkali treatment developed in this study. E. herbicola levan was then characterised by gas chromatographyâmass spectrometry and NMR. We found that levan containing LPS, but not LPS-depleted levan, induced TLR4-mediated cytokine production by bone marrow-derived dendritic cells and/or activated TLR4 reporter cells. These data indicated that the immunomodulatory properties of the levan toward TLR4-expressing immune cells were mediated by the LPS. This work also demonstrates the importance of LPS removal when assessing the immunomodulatory activity of polysaccharides
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A novel terpene synthase controls differences in anti-aphrodisiac pheromone production between closely related Heliconius butterflies.
Plants and insects often use the same compounds for chemical communication, but not much is known about the genetics of convergent evolution of chemical signals. The terpene (E)-ÎČ-ocimene is a common component of floral scent and is also used by the butterfly Heliconius melpomene as an anti-aphrodisiac pheromone. While the biosynthesis of terpenes has been described in plants and microorganisms, few terpene synthases (TPSs) have been identified in insects. Here, we study the recent divergence of 2 species, H. melpomene and Heliconius cydno, which differ in the presence of (E)-ÎČ-ocimene; combining linkage mapping, gene expression, and functional analyses, we identify 2 novel TPSs. Furthermore, we demonstrate that one, HmelOS, is able to synthesise (E)-ÎČ-ocimene in vitro. We find no evidence for TPS activity in HcydOS (HmelOS ortholog of H. cydno), suggesting that the loss of (E)-ÎČ-ocimene in this species is the result of coding, not regulatory, differences. The TPS enzymes we discovered are unrelated to previously described plant and insect TPSs, demonstrating that chemical convergence has independent evolutionary origins
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