7 research outputs found

    A New Multilevel Modelling Approach for Clustered Survival Data

    Get PDF

    Bijagual River Watershed, Costa Rica: Improving Watershed Health & Engaging Local Communities in Monitoring and Outreach

    Full text link
    The Bijagual Center for Environmental Education and Conservation (BCEEC) owns and operates the Bijagual Ecological Reserve (BER) in Sarapiquí, Costa Rica. In order to assist the BER to engage community members in reforestation efforts as well as monitor the outcomes of these efforts, this report summarizes environmental attitudes and interests in the region, provides geospatial analysis to support the BER in identifying land use patterns and areas to target for reforestation and provides materials for a water quality monitoring program and educational interpretive signage system. The body of the report is divided into four sections: social research, geospatial analysis, stream sampling/water quality monitoring, and signage. Each of these four sections include an introduction, methods, results and recommendations as appropriate.Master of Science & Master of Landscape ArchitectureSchool for Environment and SustainabilityUniversity of Michiganhttps://deepblue.lib.umich.edu/bitstream/2027.42/143170/1/Bijagual_River_Watershed_317.pd

    Inhibition of GABAA receptors in intestinal stem cells prevents chemoradiotherapy-induced intestinal toxicity.

    Full text link
    peer reviewedLethal intestinal tissue toxicity is a common side effect and a dose-limiting factor in chemoradiotherapy. Chemoradiotherapy can trigger DNA damage and induce P53-dependent apoptosis in LGR5+ intestinal stem cells (ISCs). Gamma-aminobutyric acid (GABA) and its A receptors (GABAAR) are present in the gastrointestinal tract. However, the functioning of the GABAergic system in ISCs is poorly defined. We found that GABAAR α1 (GABRA1) levels increased in the murine intestine after chemoradiotherapy. GABRA1 depletion in LGR5+ ISCs protected the intestine from chemoradiotherapy-induced P53-dependent apoptosis and prolonged animal survival. The administration of bicuculline, a GABAAR antagonist, prevented chemoradiotherapy-induced ISC loss and intestinal damage without reducing the chemoradiosensitivity of tumors. Mechanistically, it was associated with the reduction of reactive oxygen species-induced DNA damage via the L-type voltage-dependent Ca2+ channels. Notably, flumazenil, a GABAAR antagonist approved by the U.S. Food and Drug Administration, rescued human colonic organoids from chemoradiotherapy-induced toxicity. Therefore, flumazenil may be a promising drug for reducing the gastrointestinal side effects of chemoradiotherapy.Taishan Pandeng Scholar Program of Shandong Provinc

    2-Deoxy-D-glucose ameliorates inflammation and fibrosis in a silicosis mouse model by inhibiting hypoxia-inducible factor-1α in alveolar macrophages

    No full text
    Inhaling silica causes the occupational illness silicosis, which mostly results in the gradual fibrosis of lung tissue. Previous research has demonstrated that hypoxia-inducible factor-1α (HIF-1α) and glycolysis-related genes are up-regulated in silicosis. The role of 2-deoxy-D-glucose (2-DG) as an inhibitor of glycolysis in silicosis mouse models and its molecular mechanisms remain unclear. Therefore, we used 2-DG to observe its effect on pulmonary inflammation and fibrosis in a silicosis mouse model. Furthermore, in vitro cell experiments were conducted to explore the specific mechanisms of HIF-1α. Our study found that 2-DG down-regulated HIF-1α levels in alveolar macrophages induced by silica exposure and reduced the interleukin-1β (IL-1β) level in pulmonary inflammation. Additionally, 2-DG reduced silica-induced pulmonary fibrosis. From these findings, we hypothesize that 2-DG reduced glucose transporter 1 (GLUT1) expression by inhibiting glycolysis, which inhibits the expression of HIF-1α and ultimately reduces transcription of the inflammatory cytokine, IL-1β, thus alleviating lung damage. Therefore, we elucidated the important regulatory role of HIF-1α in an experimental silicosis model and the potential defense mechanisms of 2-DG. These results provide a possible effective strategy for 2-DG in the treatment of silicosis

    VX-765 attenuates silica-induced lung inflammatory injury and fibrosis by modulating alveolar macrophages pyroptosis in mice

    No full text
    Silicosis is a diffuse fibrotic lung disease in which excessive inflammatory responses are triggered by silica exposure. Pyroptosis, a pro-inflammatory mode of programmed cell death, is mediated by gasdermin and may play a pivotal role in the development of silicosis. The caspase-1 inhibitor, VX-765, was used in vivo and in vitro to investigate the effects of silica-induced early inflammatory injury and later lung fibrosis. Our findings show that VX-765 reduces inflammatory lung injury by inhibiting silica-induced pyroptosis of alveolar macrophages in a silicosis mouse model. VX-765 limits the infiltration of inflammatory M1 alveolar macrophages, decreasing expression of inflammatory cytokines, including IL-1β, TNF-α, IL-6, CCL2, and CCL3, and down-regulating endogenous DAMPs and inflammatory immune-related cell pattern recognition receptors TLR4 and NLRP3. Furthermore, VX-765 alleviates fibrosis by down-regulating α-smooth muscle actin (α-SMA), collagen, and fibronectin. In this study, we illustrate that Alveolar macrophages pyroptosis occur in the early stages of silicosis, and VX-765 can alleviate the development of silicosis by inhibiting the pyroptosis signaling pathway. These results may provide new insight into the prevention and treatment of early-stage silicosis
    corecore