140 research outputs found
Tryptophan-kynurenine pathway as a novel link between gut microbiota and schizophrenia: A review
Gut microbiota and its metabolite tryptophan play an important role in regulating neurotransmission, immune homeostasis and oxidative stress which are critical for brain development. The kynurenine pathway is the main route of tryptophan catabolism. Kynurenine metabolites regulate many biological processes including host-microbiome communication, immunity and oxidative stress, as well as neuronal excitability. The accumulation of metabolites produced by kynurenine pathway in brain results in the activation of the immune system (increase in the levels of inflammatory factors) and oxidative stress (production of reactive oxygen species, ROS), which are associated with mental disorders, for example schizophrenia. Thus, it was hypothesized that perturbations in kynurenine pathway could cause activation of immunity, and that oxidative stress may be involved in the etiology of schizophrenia. The present work is a review of the latest studies on the possible role of kynurenine pathway in schizophrenia, and mechanism(s) involved
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An Interview with APPLE Lecture Speaker Professor James Pennebaker
On February 24, 2017, the TESOL/AL Web Journal (represented by Eun Young Kang, Yulin Liu, Sarah Sok, Di Yu and Yuna Seong) had the opportunity to sit down with Professor James Pennebaker, guest speaker for the 2017 Applied Linguistics & Language Education (APPLE) Lecture Series, hosted annually by the TESOL/Applied Linguistics Programs at Teachers College, Columbia University. Professor Pennebaker spoke about his research and advice he has for current and future researchers in the TESOL and Applied Linguistics fields.
Professor James Pennebaker is the Regents Professor of Psychology at the University of Texas at Austin. He is also the Executive Director of a university-wide educational initiative called Project 2021. His work on expressive writing found that physical health can improve by writing about traumatic events/experience. We thank Professor Pennebaker for the great opportunity to learn more about his work and research. We also thank Fred Tsutagawa for videotaping and Dr. Hoa Nguyen for coordinating the APPLE Lecture Series Interview
Simulated Microgravity Altered the Metabolism of Loureirin B and the Expression of Major Cytochrome P450 in Liver of Rats
Loureirin B (LB) is the marker compound of dragon blood (DB), which exhibits great potentials in protecting astronauts’ health against radiation and simulated microgravity (SM). Pharmacokinetics of LB is reported to be significantly altered by SM. Here, we investigated key metabolic features of LB in rat liver microsome (RLM) and the effects of SM on LB metabolism as well as on expression of major hepatic cytochrome P450 (CYP450) isoforms. Ten metabolites were tentatively identified based on fragmentation pathways using LC-MS/MS method and elimination kinetics of LB followed a typical Michaelis–Menten equation (Vmax was 1.32 μg/min/mg and Km was 13.33 μg/mL). CYP1A2, CYP2C11, CYP2D1, and CYP3A2 were involved in the metabolism of LB and the relative strength was: CYP3A2 > CYP2C11 > CYP2D1 > CYP1A2. Comparative studies suggested that elimination of LB in RLM was remarkably increased by 3-day and 14-day SM, and the generation of identified metabolites was affected as well. Additionally, 3-day and 14-day SM showed obvious regulatory effects on the expression of major CYP450 isoforms, which might contribute to the increased elimination of LB. The data provided supports for the application of DB as a protective agent and the reasonable use of current medications metabolized by hepatic CYP450 in space missions
Effect of miR-125b on dermal papilla cells of goat secondary hair follicle
Background: MicroRNAs (miRNAs) are endogenous noncoding RNAs that
regulate various biological processes. miR-125b is a miRNA that has
been reported to be critical for hair follicle (HF) morphogenesis and
development. We identified that the expression of miR-125b varies
during an individual hair cycle (anagen, catagen, and telogen) in the
skin of cashmere goats. We constructed a gain model (by overexpressing
miR-125b) and a loss model (by inhibiting endogenous miR-125b) based on
dermal papilla cells (DPCs) to further investigate the role of miR-125b
in HF cycle. In addition, we used a dual-luciferase system to highlight
the predicated target genes of miR-125b. Results: We found that
miR-125b affects the expression of FGF5, IGF-1, SHH, TNF-\u3b1, MSX2,
LEF-1, FGF7, NOGGIN, BMP2, BMP4, TGF-\u3b21, and \u3b2-catenin. The
dual-luciferase assay further validated a direct interaction between
miR-125b and FGF5 and TNF-\u3b1. Conclusion: miR-125b affects the
expression levels of genes related to hair cycle and may also play a
critical role in regulating the periodic development of HF
Gut microbial biomarkers for the treatment response in first-episode, drug-naive schizophrenia: a 24-week follow-up study
Preclinical studies have shown that the gut microbiota can play a role in schizophrenia (SCH) pathogenesis via the gut-brain axis. However, its role in the antipsychotic treatment response is unclear. Here, we present a 24-week follow-up study to identify gut microbial biomarkers for SCH diagnosis and treatment response, using a sample of 107 first-episode, drug-naive SCH patients, and 107 healthy controls (HCs). We collected biological samples at baseline (all participants) and follow-up time points after risperidone treatment (SCH patients). Treatment response was assessed using the Positive and Negative Symptoms Scale total (PANSS-T) score. False discovery rate was used to correct for multiple testing. We found that SCH patients showed lower alpha-diversity (the Shannon and Simpson\u27s indices) compared to HCs at baseline (p = 1.21 x 10(-9), 1.23 x 10(-8), respectively). We also found a significant difference in beta-diversity between SCH patients and HCs (p = 0.001). At baseline, using microbes that showed different abundance between patients and controls as predictors, a prediction model can distinguish patients from HCs with an area under the curve (AUC) of 0.867. In SCH patients, after 24 weeks of risperidone treatment, we observed an increase of alpha-diversity toward the basal level of HCs. At the genus level, we observed decreased abundance of Lachnoclostridium (p = 0.019) and increased abundance Romboutsia (p = 0.067). Moreover, the treatment response in SCH patients was significantly associated with the basal levels of Lachnoclostridium and Romboutsia (p = 0.005 and 0.006, respectively). Our results suggest that SCH patients may present characteristic microbiota, and certain microbiota biomarkers may predict treatment response in this patient population
Long-term prednisone treatment causes fungal microbiota dysbiosis and alters the ecological interaction between gut mycobiome and bacteriome in rats
Glucocorticoids (GCs) are widely used in the treatment of immune-mediated diseases due to their anti-inflammatory and immunosuppressive effects. Prednisone is one of the most commonly used GCs. However, it is still unknown whether prednisone affects gut fungi in rats. Herein we investigated whether prednisone changed the composition of gut fungi and the interactions between gut mycobiome and bacteriome/fecal metabolome in rats. Twelve male Sprague–Dawley rats were randomly assigned to a control group and a prednisone group which received prednisone daily by gavage for 6 weeks. ITS2 rRNA gene sequencing of fecal samples was performed to identify differentially abundant gut fungi. The associations between gut mycobiome and bacterial genera/fecal metabolites obtained from our previously published study were explored by using Spearman correlation analysis. Our data showed that there were no changes in the richness of gut mycobiome in rats after prednisone treatment, but the diversity increased significantly. The relative abundance of genera Triangularia and Ciliophora decreased significantly. At the species level, the relative abundance of Aspergillus glabripes increased significantly, while Triangularia mangenotii and Ciliophora sp. decreased. In addition, prednisone altered the gut fungi-bacteria interkingdom interactions in rats after prednisone treatment. Additionally, the genus Triangularia was negatively correlated with m-aminobenzoic acid, but positively correlated with hydrocinnamic acid and valeric acid. Ciliophora was negatively correlated with phenylalanine and homovanillic acid, but positively correlated with 2-Phenylpropionate, hydrocinnamic acid, propionic acid, valeric acid, isobutyric acid, and isovaleric acid. In conclusion, long-term prednisone treatment caused fungal microbiota dysbiosis and might alter the ecological interaction between gut mycobiome and bacteriome in rats
Quantitative analysis of macro steel fiber influence on crack geometry and water permeability of concrete
"Available online 29 December 2017"In this work, the water permeability of the cracked concrete has been investigated. Three types of cylindrical
specimens with different fiber content were pre-cracked by the feedback controlled splitting test, and the specimens without any fiber reinforcement were also studied as reference. The water permeability of the specimens with different crack width was measured by hydraulic permeability test. The coordinate data of the crack surface was collected by the self designed data acquisition system, the total crack length and surface area of the samples were analyzed, the crack geometry (tortuosity and roughness) was evaluated quantitatively. A modified factor ξ was introduced to the Poiseuille law to verify the permeability of the cracked specimen. The results showed that with the addition of macro steel fibers, the deformability of the specimens was improved significantly and the crack width could be controlled. The coefficient of the water permeability of the specimens was declined by fiber addition, the modified Poiseuille law could be used to evaluate the water permeability of the cracked concrete, the modified factor ξ decreased with the increasing of fiber dosage. The crack tortuosity and surface roughness increased obviously with the addition of steel fiber.The authors gratefully acknowledge the National Natural Science Foundation of China, Grants:
51578109 and 51121005.info:eu-repo/semantics/publishedVersio
Anomalous excitonic phase diagram in band-gap-tuned Ta2Ni(Se,S)5
During a band-gap-tuned semimetal-to-semiconductor transition, Coulomb
attraction between electrons and holes can cause spontaneously formed excitons
near the zero-band-gap point, or the Lifshitz transition point. This has become
an important route to realize bulk excitonic insulators -- an insulating ground
state distinct from single-particle band insulators. How this route manifests
from weak to strong coupling is not clear. In this work, using angle-resolved
photoemission spectroscopy (ARPES) and high-resolution synchrotron x-ray
diffraction (XRD), we investigate the broken symmetry state across the
semimetal-to-semiconductor transition in a leading bulk excitonic insulator
candidate system Ta2Ni(Se,S)5. A broken symmetry phase is found to be
continuously suppressed from the semimetal side to the semiconductor side,
contradicting the anticipated maximal excitonic instability around the Lifshitz
transition. Bolstered by first-principles and model calculations, we find
strong interband electron-phonon coupling to play a crucial role in the
enhanced symmetry breaking on the semimetal side of the phase diagram. Our
results not only provide insight into the longstanding debate of the nature of
intertwined orders in Ta2NiSe5, but also establish a basis for exploring
band-gap-tuned structural and electronic instabilities in strongly coupled
systems.Comment: 27 pages, 4 + 9 figure
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