55 research outputs found
Next generation sequencing as a new detection strategy for maternal cell contamination in clinical prenatal samples
Objectives: The maternal cell contamination in chorionic villus or amniotic fluid presents a serious preanalytical risk for prenatal misdiagnosis. The following study presents and validates a novel process for identifying MCC by detecting short tandem repeat markers on Ion Proton system. Initially, MCC testing was performed during the detection of chromosomal abnormalities so as to improve the detection efficiency and accuracy of this method.
Material and methods: More than 70 STR loci were selected to establish the detection progress. Capillary electrophoresis was used to compare the next generation sequencing detection results, as well as to identify the optimal STR on Ion Proton system. Evaluation criteria for maternal cell contamination were set, and the automated data analysis was performed. The detection sensitivity was validated via 4 groups with mixed samples and different proportions.
Results: Consequently, twenty-three clinical samples were tested to evaluate the detection accuracy. In addition, 14 reliable STR loci, which were stably detected in more than 25 samples, were found. The detection sensitivity in maternal cell contamination was no less than 20%, while its accuracy reached 100% in clinical samples.
Conclusions: Finally, we established and validated a novel detection procedure for maternal cell contamination in clinical prenatal samples using next generation sequencing. This procedure allowed us to simultaneously perform prenatal testing and MCC testing. Unlike the traditional capillary electrophoresis, this method is rapid, highly sensitive, and suitable for wide range of clinical applications
Plant pathogen resistance is mediated by recruitment of specific rhizosphere fungi
Beneficial interactions between plants and rhizosphere microorganisms are key determinants of plant health with the potential to enhance the sustainability of agricultural practices. However, pinpointing the mechanisms that determine plant disease protection is often difficult due to the complexity of microbial and plant-microbe interactions and their links with the plant’s own defense systems. Here, we found that the resistance level of different banana varieties was correlated with the plant’s ability to stimulate specific fungal taxa in the rhizosphere that are able to inhibit the Foc TR4 pathogen. These fungal taxa included members of the genera Trichoderma and Penicillium, and their growth was stimulated by plant exudates such as shikimic acid, D-(-)-ribofuranose, and propylene glycol. Furthermore, amending soils with these metabolites enhanced the resistance of a susceptible variety to Foc TR4, with no effect observed for the resistant variety. In total, our findings suggest that the ability to recruit pathogen-suppressive fungal taxa may be an important component in determining the level of pathogen resistance exhibited by plant varieties. This perspective opens up new avenues for improving plant health, in which both plant and associated microbial properties are considered
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PTER is a N-acetyltaurine hydrolase that regulates feeding and obesity.
Taurine is a conditionally essential micronutrient and one of the most abundant amino acids in humans1-3. In endogenous taurine metabolism, dedicated enzymes are involved in the biosynthesis of taurine from cysteine and in the downstream metabolism of secondary taurine metabolites4,5. One taurine metabolite is N-acetyltaurine6. Levels of N-acetyltaurine are dynamically regulated by stimuli that alter taurine or acetate flux, including endurance exercise7, dietary taurine supplementation8 and alcohol consumption6,9. So far, the identities of the enzymes involved in N-acetyltaurine metabolism, and the potential functions of N-acetyltaurine itself, have remained unknown. Here we show that the body mass index associated orphan enzyme phosphotriesterase-related (PTER)10 is a physiological N-acetyltaurine hydrolase. In vitro, PTER catalyses the hydrolysis of N-acetyltaurine to taurine and acetate. In mice, PTER is expressed in the kidney, liver and brainstem. Genetic ablation of Pter in mice results in complete loss of tissue N-acetyltaurine hydrolysis activity and a systemic increase in N-acetyltaurine levels. After stimuli that increase taurine levels, Pter knockout mice exhibit reduced food intake, resistance to diet-induced obesity and improved glucose homeostasis. Administration of N-acetyltaurine to obese wild-type mice also reduces food intake and body weight in a GFRAL-dependent manner. These data place PTER into a central enzymatic node of secondary taurine metabolism and uncover a role for PTER and N-acetyltaurine in body weight control and energy balance
Activation of P2X7-mediated apoptosis Inhibits DMBA/TPA-induced formation of skin papillomas and cancer in mice
<p>Abstract</p> <p>Background</p> <p>The study tested the hypothesis that apoptosis can prevent and control growth of neoplastic cells. Previous studies in-vitro have shown that the pro-apoptotic P2X<sub>7 </sub>receptor regulates growth of epithelial cells. The specific objective of the present study was to understand to what degree the P2X<sub>7 </sub>system controls development and growth of skin cancer in vivo, and what cellular and molecular mechanisms are involved in the P2X<sub>7 </sub>action.</p> <p>Methods</p> <p>Skin neoplasias in mice (papillomas, followed by squamous spindle-cell carcinomas) were induced by local application of DMBA/TPA. Experiments in-vitro utilized cultured epidermal keratinocytes generated from wild-type or from P2X<sub>7</sub>-null mice. Assays involved protein immunostaining and Western blots; mRNA real-time qPCR; and apoptosis (evaluated in situ by TUNEL and quantified in cultured keratinocytes as solubilized DNA or by ELISA). Changes in cytosolic calcium or in ethidium bromide influx (P2X<sub>7 </sub>pore formation) were determined by confocal laser microscopy.</p> <p>Results</p> <p>(a) Co-application on the skin of the P2X<sub>7 </sub>specific agonist BzATP inhibited formation of DMBA/TPA-induced skin papillomas and carcinomas. At the completion of study (week 28) the proportion of living animals with cancers in the DMBA/TPA group was 100% compared to 43% in the DMBA/TPA+BzATP group. (b) In the normal skin BzATP affected mainly P2X<sub>7</sub>-receptor – expressing proliferating keratinocytes, where it augmented apoptosis without evoking inflammatory changes. (c) In BzATP-treated mice the degree of apoptosis was lesser in cancer than in normal or papilloma keratinocytes. (d) Levels of P2X<sub>7 </sub>receptor, protein and mRNA were 4–5 fold lower in cancer tissues than in normal mouse tissues. (e) In cultured mouse keratinocytes BzATP induced apoptosis, formation of pores in the plasma membrane, and facilitated prolonged calcium influx. (f) The BzATP-induced apoptosis, pore-formation and augmented calcium influx had similar dose-dependence for BzATP. (g) Pore formation and the augmented calcium influx were depended on the expression of the P2X<sub>7 </sub>receptor, while the BzATP-induced apoptosis depended on calcium influx. (h) The BzATP-induced apoptosis could be blocked by co-treatment with inhibitors of caspase-9 and caspase-3, but not of caspase-8.</p> <p>Conclusion</p> <p>(a) P2X<sub>7</sub>-dependent apoptosis is an important mechanism that controls the development and progression of epidermal neoplasia in the mouse. (b) The P2X<sub>7</sub>-dependent apoptosis is mediated by calcium influx via P2X<sub>7 </sub>pores, and involves the caspase-9 (mitochondrial) pathway. (c) The diminished pro-apoptotic effect of BzATP in mouse cancer keratinocytes is possibly the result of low expression of the P2X<sub>7 </sub>receptor. (d) Activation of P2X<sub>7</sub>-dependent apoptosis, e.g. with BzATP could be a novel chemotherapeutic growth-preventive modality for papillomas and epithelial cancers in vivo.</p
Detecting Neutrinos from Supernova Bursts in PandaX-4T
Neutrinos from core-collapse supernovae are essential for the understanding
of neutrino physics and stellar evolution. The dual-phase xenon dark matter
detectors can provide a way to track explosions of galactic supernovae by
detecting neutrinos through coherent elastic neutrino-nucleus scatterings. In
this study, a variation of progenitor masses as well as explosion models are
assumed to predict the neutrino fluxes and spectra, which result in the number
of expected neutrino events ranging from 6.6 to 13.7 at a distance of 10 kpc
over a 10-second duration with negligible backgrounds at PandaX-4T. Two
specialized triggering alarms for monitoring supernova burst neutrinos are
built. The efficiency of detecting supernova explosions at various distances in
the Milky Way is estimated. These alarms will be implemented in the real-time
supernova monitoring system at PandaX-4T in the near future, providing the
astronomical communities with supernova early warnings.Comment: 9 pages,6 figure
Search for light dark matter from atmosphere in PandaX-4T
We report a search for light dark matter produced through the cascading decay
of mesons, which are created as a result of inelastic collisions between
cosmic rays and Earth's atmosphere. We introduce a new and general framework,
publicly accessible, designed to address boosted dark matter specifically, with
which a full and dedicated simulation including both elastic and quasi-elastic
processes of Earth attenuation effect on the dark matter particles arriving at
the detector is performed. In the PandaX-4T commissioning data of 0.63
tonneyear exposure, no significant excess over background is observed.
The first constraints on the interaction between light dark matter generated in
the atmosphere and nucleus through a light scalar mediator are obtained. The
lowest excluded cross-section is set at for
dark matter mass of MeV and mediator mass of 300 MeV. The
lowest upper limit of to dark matter decay branching ratio is
A Search for Light Fermionic Dark Matter Absorption on Electrons in PandaX-4T
We report a search on a sub-MeV fermionic dark matter absorbed by electrons
with an outgoing active neutrino using the 0.63 tonne-year exposure collected
by PandaX-4T liquid xenon experiment. No significant signals are observed over
the expected background. The data are interpreted into limits to the effective
couplings between such dark matter and electrons. For axial-vector or vector
interactions, our sensitivity is competitive in comparison to existing
astrophysical bounds on the decay of such dark matter into photon final states.
In particular, we present the first direct detection limits for an axial-vector
(vector) interaction which are the strongest in the mass range from 25 to 45
(35 to 50) keV/c
Wireless power transmission for remote-relay-nodes-aided smart metering
Wireless power transmission is a promising technique to provide continuous power supply for the limited capacitance of smart meters (SMs) with short distance communication. In this study, the authors propose a remote-relay-nodes (RRNs)-aided wireless SM system, where several geographically separated RRNs are connected to a concentrator or an acquire terminal via radio-over-fibre. A RRN selection scheme is employed in the wireless power transfer phase. With the energy harvested, the SM can report special or urgent events in the wireless information transfer phase. The asymptotic reporting probability and reliability of smart metering are derived in terms of close form over fading channels. Numerical results are provided to verify the theoretical analysis. The optimal deployment of RRNs can be also efficiently obtained by averaging the locations of a SM in the network
Silage Fermentation: A Potential Biological Approach for the Long-Term Preservation and Recycling of Polyphenols and Terpenes in Globe Artichoke (Cynara scolymus L.) By-Products
An economic and effective method for storage is necessary to make full use of the nature of active components in artichoke by-products and ease environmental pressure. In this paper, the potential of silage fermentation for the preservation and recycling of polyphenols and terpenes in artichoke by-products is evaluated. The silage of artichoke by-products is characterized by lactic acid bacteria fermentation. Silage distinctly increases the abundance of lactic acid bacteria in artichoke by-products, such as Lactobacillus, Lactococcus, Serratia, and Weissella, and greatly increases the abundance of Firmicutes. The improvement of the microorgan structure and composition is of great significance for the quality of artichoke by-products. Polyphenols in the stems and leaves of artichokes are preserved well in silage. Among the 18 polyphenol compounds detected by high performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (HPLC-QqQ-MS/MS), the contents of 11 phenolic acids and four flavonoids increased significantly. For terpenes detected by gas chromatography-mass spectrometry (GC-MS), the contents of four pentacyclic triterpenoids increased significantly, while two sterols were kept stable in the silage process. Silage is a potential biotechnology for the long-term preservation of bioactive components, such as polyphenols and terpenes in artichoke by-products, and the results provide a scientific basis for the efficient utilization of by-products
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