排序方式: 共有170条查询结果,搜索用时 10 毫秒
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King Alison E. Congreves Katelyn A. Deen Bill Dunfield Kari E. Simpson Myrna J. Voroney R. Paul Wagner-Riddle Claudia 《Plant and Soil》2020,454(1-2):207-215
Plant and Soil - There is a trend of increasing woody biomass in tropical savannas. Here we ask what effect this increase may have on soil carbon pools and fluxes. Using a field experiment we... 相似文献
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Schwarz A Juarez JA Richards J Rath B Machaca VQ Castro YE Málaga ES Levy K Gilman RH Bern C Verastegui M Levy MZ 《International journal for parasitology》2011,41(6):591-594
Insecticide-impregnated nets can kill triatomine bugs, but it remains unclear whether they can protect against Chagas disease transmission. In a field trial in Quequeña, Peru, sentinel guinea pigs placed in intervention enclosures covered by deltamethrin-treated nets showed significantly lower antibody responses to saliva of Triatoma infestans compared with animals placed in pre-existing control enclosures. Our results strongly suggest that insecticide-treated nets prevent triatomine bites and can thereby protect against infection with Trypanosoma cruzi. Anti-salivary immunoassays are powerful new tools to evaluate intervention strategies against Chagas disease. 相似文献
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Sophia A. Mahoney Ravinandan Venkatasubramanian Mary A. Darrah Katelyn R. Ludwig Nicholas S. VanDongen Nathan T. Greenberg Abigail G. Longtine David A. Hutton Vienna E. Brunt Judith Campisi Simon Melov Douglas R. Seals Matthew J. Rossman Zachary S. Clayton 《Aging cell》2024,23(3):e14060
Cellular senescence and the senescence-associated secretory phenotype (SASP) contribute to age-related arterial dysfunction, in part, by promoting oxidative stress and inflammation, which reduce the bioavailability of the vasodilatory molecule nitric oxide (NO). In the present study, we assessed the efficacy of fisetin, a natural compound, as a senolytic to reduce vascular cell senescence and SASP factors and improve arterial function in old mice. We found that fisetin decreased cellular senescence in human endothelial cell culture. In old mice, vascular cell senescence and SASP-related inflammation were lower 1 week after the final dose of oral intermittent (1 week on—2 weeks off—1 weeks on dosing) fisetin supplementation. Old fisetin-supplemented mice had higher endothelial function. Leveraging old p16-3MR mice, a transgenic model allowing genetic clearance of p16INK4A-positive senescent cells, we found that ex vivo removal of senescent cells from arteries isolated from vehicle- but not fisetin-treated mice increased endothelium-dependent dilation, demonstrating that fisetin improved endothelial function through senolysis. Enhanced endothelial function with fisetin was mediated by increased NO bioavailability and reduced cellular- and mitochondrial-related oxidative stress. Arterial stiffness was lower in fisetin-treated mice. Ex vivo genetic senolysis in aorta rings from p16-3MR mice did not further reduce mechanical wall stiffness in fisetin-treated mice, demonstrating lower arterial stiffness after fisetin was due to senolysis. Lower arterial stiffness with fisetin was accompanied by favorable arterial wall remodeling. The findings from this study identify fisetin as promising therapy for clinical translation to target excess cell senescence to treat age-related arterial dysfunction. 相似文献
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Anne M. Roesler Sarah A. Wicher Jovanka Ravix Rodney D. Britt Jr. Logan Manlove Jacob J. Teske Katelyn Cummings Michael A. Thompson Carol Farver Peter MacFarlane Christina M. Pabelick Y.S. Prakash 《Journal of cellular physiology》2019,234(8):14187-14197
Airway smooth muscle (ASM) regulation of airway structure and contractility is critical in fetal/neonatal physiology in health and disease. Fetal lungs experience higher Ca2+ environment that may impact extracellular Ca2+ ([Ca2+]o) sensing receptor (CaSR). Well-known in the parathyroid gland, CaSR is also expressed in late embryonic lung mesenchyme. Using cells from 18-22 week human fetal lungs, we tested the hypothesis that CaSR regulates intracellular Ca2+ ([Ca2+]i) in fetal ASM (fASM). Compared with adult ASM, CaSR expression was higher in fASM, while fluorescence Ca2+ imaging showed that [Ca2+]i was more sensitive to altered [Ca2+]o. The fASM [Ca2+]i responses to histamine were also more sensitive to [Ca2+]o (0–2 mM) compared with an adult, enhanced by calcimimetic R568 but blunted by calcilytic NPS2143. [Ca2+]i was enhanced by endogenous CaSR agonist spermine (again higher sensitivity compared with adult). Inhibition of phospholipase C (U73122; siRNA) or inositol 1,4,5-triphosphate receptor (Xestospongin C) blunted [Ca2+]o sensitivity and R568 effects. NPS2143 potentiated U73122 effects. Store-operated Ca2+ entry was potentiated by R568. Traction force microscopy showed responsiveness of fASM cellular contractility to [Ca2+]o and NPS2143. Separately, fASM proliferation showed sensitivity to [Ca2+]o and NPS2143. These results demonstrate functional CaSR in developing ASM that modulates airway contractility and proliferation. 相似文献
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Ben Moree Katelyn Connell Richard?B. Mortensen C.?Tony Liu Stephen?J. Benkovic Joshua Salafsky 《Biophysical journal》2015,109(4):806-815
We present here a straightforward, broadly applicable technique for real-time detection and measurement of protein conformational changes in solution. This method is based on tethering proteins labeled with a second-harmonic generation (SHG) active dye to supported lipid bilayers. We demonstrate our method by measuring the conformational changes that occur upon ligand binding with three well-characterized proteins labeled at lysine residues: calmodulin (CaM), maltose-binding protein (MBP), and dihydrofolate reductase (DHFR). We also create a single-site cysteine mutant of DHFR engineered within the Met20 catalytic loop region and study the protein’s structural motion at this site. Using published x-ray crystal structures, we show that the changes in the SHG signals upon ligand binding are the result of structural motions that occur at the labeled sites between the apo and ligand-bound forms of the proteins, which are easily distinguished from each other. In addition, we demonstrate that different magnitudes of the SHG signal changes are due to different and specific ligand-induced conformational changes. Taken together, these data illustrate the potential of the SHG approach for detecting and measuring protein conformational changes for a wide range of biological applications. 相似文献
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