111 research outputs found

    Long term water integration in interconnected ramets of stoloniferous grass, buffalograss

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    Buffalograss (Buchloë dactyloides) is known for its drought resistant character. Natural resources are patchily distributed and resource sharing between interconnected ramets can enhance the performance of the whole genet. In order to examine whether there exists long term water integration between interconnected ramets of buffalograss, a greenhouse experiment was conducted. Interconnected ramet pairs of stoloniferous buffalograss were planted in two partitioned similar-sized containers and subjected to homogeneous (20 ml pot-1 d-1 or 100 - 150 ml pot-1 d-1) or heterogeneous (20 ml pot-1 d-1 vs. 100-150 ml pot-1 d-1) water supply; the whole experiment lasted for 91 days. In heterogeneous treatment, water translocation was equally effective in acropetal and basipetal directions. Elder ramet was more efficient in water use, but rooted ramet of elder ramet in moist condition experienced significant cost when it was connected to younger ramet in dry condition; whereas, no cost was found in any fragment of younger donor ramet. Ramet in dry condition produced more biomass than its connected ramet in moist condition and developed larger leaves. This “oversharing” phenomenon indicated that no net cost was involved in water integration, and water might not be the only resources transported within stolon xylem. Overall, long term water integration is an important strategy for buffalograss to cope with adverse natural drought conditions.Keywords: Water integration, interconnected ramets, heterogeneous treatment, Buchloë dactyloides, oversharingAfrican Journal of Biotechnology Vol. 9(34), pp. 5503-5510, 23 August, 201

    Black tea preserves intestinal homeostasis through balancing barriers and microbiota in mice

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    IntroductionBlack tea, a beverage consumed worldwide, possesses favorable effects on gastrointestinal tract, including nourishing stomach and promoting digestion. Nevertheless, its specific effects on intestinal homeostasis remains inconclusive.MethodsWe applied black tea to mice prior to inducing colitis with DSS and then monitored their body weight and disease activity index (DAI) daily. When sacrificed, we measured intestinal permeability and conducted analyses of mucin and tight junction proteins. We detected inflammatory cytokines, immune cells, and related inflammatory signaling pathways. In addition, the gut microbiota was analyzed through 16S rRNA sequencing, and the concentrations of short-chain fatty acids (SCFAs) were also measured.ResultsThe results showed that black tea-treated group significantly rescued the DSS-disrupted intestinal structure. It reduced the relative abundance of the pathogenic bacterium Turicibacter, while increased the abundance of beneficial bacteria norank_f_Muribaculaceae and restored the contents of SCFAs such as acetate, propionate, and butyrate. It also protected the intestinal barrier by reducing the levels of immune response-related factors (e.g., TNF-α, IL-6, IL-1β) and increasing the expression of tight junction proteins (TJs) (e.g., ZO-1, occludin). Furthermore, black tea exhibited the capacity to suppress the expression of MMP-9 and ICAM-1, as well as to inhibit the activation of NF-κB signaling pathway.DiscussionOur findings provide a theoretical framework that elucidates the mechanisms by which black tea preserves intestinal homeostasis, highlighting its potential as a preventive strategy against intestinal disruptions. This study contributes to the understanding of the dietary effects of black tea on gastrointestinal health

    Bisphosphonates Suppress Insulin-Like Growth Factor 1-Induced Angiogenesis Via the HIF-1α/VEGF Signaling Pathways in Human Breast Cancer Cells

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    Adjunctive chemotherapy with bisphosphonates has been reported to delay bone metastasis and improve overall survival in breast cancer. Aside from its antiresorptive effect, bisphosphonates exhibit antitumor activities, in vitro and in vivo, via several mechanisms, including antiangiogenesis. In this study, we investigated the potential molecular mechanisms underlying the antiangiogenic effect of non-nitrogen-containing and nitrogen-containing bisphosphonates, clodronate and pamidronate, respectively, in insulin-like growth factor (IGF)-1 responsive human breast cancer cells. We tested whether bisphosphonates had any effects on hypoxia-inducible factor (HIF)-1α/vascular endothelial growth factor (VEGF) axis that plays a pivotal role in tumor angiogenesis, and our results showed that both pamidronate and clodronate significantly suppressed IGF-1-induced HIF-1α protein accumulation and VEGF expression in MCF-7 cells. Mechanistically, we found that either pamidronate or clodronate did not affect mRNA expression of HIF-1α, but they apparently promoted the degradation of IGF-1-induced HIF-1α protein. Meanwhile, we found that the presence of pamidronate and clodronate led to a dose-dependent decease in the newly-synthesized HIF-1α protein induced by IGF-1 in breast cancer cells after proteasomal inhibition, thus, indirectly reflecting the inhibition of protein synthesis. In addition, our results indicated that the inhibitory effects of bisphosphonates on the HIF-1α/VEGF axis are associated with the inhibition of the phosphoinositide 3-kinase/AKT/ mammalian target of rapamycin signaling pathways. Consistently, we demonstrated that pamidronate and clodronate functionally abrogated both in vitro and in vivo tumor angiogenesis induced by IGF-1-stimulated MCF-7 cells. These findings have highlighted an important mechanism of the pharmacological action of bisphosphonates in the inhibition of tumor angiogenesis in breast cancer cells. © 2009 UICC

    Association between living environmental quality and risk of arthritis in middle-aged and older adults: a national study in China

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    BackgroundThe association between combined environmental factors and the risk of arthritis is still scarcely studied. The present study performed cross-sectional and cohort studies to explore the association between risk score of living environment quality and the risk of arthritis in middle-aged and older adults in China.MethodsThe study was based on China Health and Retirement Longitudinal Study (CHARLS), and it recruited 17,218 participants in the cross-sectional study and 11,242 participants in the seven-year follow-up study. The living environment quality was measured by household fuel types, household water sources, room temperature, residence types, and ambient concentration of PM2.5. Logistic regression and Cox proportional hazard regression models were utilized to examine the association between the living environment quality and the risk of arthritis. Competing risk models and stratified analyses were applied to further verify our results.ResultsCompared with individuals in the suitable environment group, people who lived in moderate (OR:1.28, 95%CI: 1.14–1.43) and unfavorable environments (OR:1.49, 95%CI:1.31–1.70) showed higher risks of arthritis when considering the multiple living environmental factors (P for trend <0.001) in the cross-sectional analysis. In the follow-up study, similar results (P for trend = 0.021), moderate environment group (HR:1.26, 95%CI:1.01–1.56) and unfavorable environment group (HR: 1.36, 95%CI: 1.07–1.74), were founded.ConclusionInferior living environment might promote the development of arthritis. It is necessary for the public, especially old people, to improve the living environment, which may be the key to the primary prevention of arthritis

    Design of a Low temperature cofired ceramic wideband WideScan antenna array for millimetre‐wave applications

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    The design, fabrication, and measurement of a 7 × 7 mm-wave array antenna have been presented for 5G communications. The substrate integrated waveguide (SIW)-fed antenna element is formed of four parts: a rectangular radiating patch, a coupling slot cut onto the broadwall of the SIW, a transition layer, and a feeding layer at the bottom. The bandwidth and radiation efficiency has been improved by embedding an air cavity below the radiating patch, as the effective dielectric constant of the substrate is reduced. Moreover, a prototype has been fabricated and measured to verify the design principles. The finite array operating over 23–28 GHz has achieved active voltage standing wave ratios of less than 2 and 2.5 in the E- and H-planes while scanning up to 45° respectively. Compared with the theoretical ideal gain, the average gain drop of the measured embedded element gain is 0.73dB

    Protective CD8+ T-cell responses to cytomegalovirus driven by rAAV/GFP/IE1 loading of dendritic cells

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    Background: Recent studies demonstrate that recombinant adeno-associated virus (rAAV)-based antigen loading of dendritic cells (DCs) generates in vitro, significant and rapid cytotoxic T-lymphocyte (CTL) responses against viral antigens. Methods: We used the rAAV system to induce specific CTLs against CVM antigens for the development of cytomegalovirus HCMV) gene therapy. As an extension of the versatility of the rAAV system, we incorporated immediate-early 1 (IE1), expressed in HCMV. Our rAAV vector induced a strong stimulation of CTLs directed against the HCMV antigen IE1. We then investigated the efficiency of the CTLs in killing IE1 targeted cells. Results: A significant MHC Class I-restricted, anti-IE1-specificCTL killing was demonstrated against IE1 positive peripheral blood mononuclear cells (PBMC) after one, in vitro, stimulation. Conclusion: In summary, single PBMC stimulation with rAAV/IE1 pulsed DCs induces strong antigen specific-CTL generation. CTLs were capable to lyse low doses of peptides pulsed into target cells. These data suggest that AAV-based antigen loading of DCs is highly effective for generating human CTL responses against HCMV antigens

    Iron induces two distinct Ca<sup>2+</sup> signalling cascades in astrocytes.

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    From Europe PMC via Jisc Publications RouterHistory: ppub 2021-05-01, epub 2021-05-05Publication status: PublishedFunder: National Natural Science Foundation of China (National Science Foundation of China); Grant(s): 81871852Iron is the fundamental element for numerous physiological functions. Plasmalemmal divalent metal ion transporter 1 (DMT1) is responsible for cellular uptake of ferrous (Fe2+), whereas transferrin receptors (TFR) carry transferrin (TF)-bound ferric (Fe3+). In this study we performed detailed analysis of the action of Fe ions on cytoplasmic free calcium ion concentration ([Ca2+]i) in astrocytes. Administration of Fe2+ or Fe3+ in μM concentrations evoked [Ca2+]i in astrocytes in vitro and in vivo. Iron ions trigger increase in [Ca2+]i through two distinct molecular cascades. Uptake of Fe2+ by DMT1 inhibits astroglial Na+-K+-ATPase, which leads to elevation in cytoplasmic Na+ concentration, thus reversing Na+/Ca2+ exchanger and thereby generating Ca2+ influx. Uptake of Fe3+ by TF-TFR stimulates phospholipase C to produce inositol 1,4,5-trisphosphate (InsP3), thus triggering InsP3 receptor-mediated Ca2+ release from endoplasmic reticulum. In summary, these findings reveal the mechanisms of iron-induced astrocytic signalling operational in conditions of iron overload
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