81 research outputs found
Photothermal treatment of glioma; an in vitro study of macrophage-mediated delivery of gold nanoshells
One of the major factors that limits the treatment effectiveness for gliomas is the presence of the bloodâbrain barrier (BBB) which protects infiltrating glioma cells from the effects of anti-cancer agents. Circulating monocytes/macrophages (Ma) have a natural ability to traverse the intact and compromised BBB and loaded with anti cancer agents could be used as vectors to target tumors and surrounding tumor infiltrated tissue. Nanoshells (NS) are composed of a dielectric core (silica) coated with an ultrathin gold layer which converts absorbed near-infrared light (NIR) to heat with an extremely high efficacy and stability. We have investigated the effects of exposure to laser NIR on multicell human glioma spheroids infiltrated with empty (containing no nanoshells) or nanoshell loaded macrophages. Our results demonstrated that; (1) macrophages could efficiently take up bare or coated (PEGylated) gold NS: (2) NS loaded macrophages infiltrated into glioma spheroids to the same or, in some cases, to a greater degree than empty Ma; (3) NIR laser irradiation of spheroids incorporating NS loaded macrophages resulted in complete growth inhibition in an irradiance dependent manner, and (4) spheroids infiltrated with empty macrophages had growth curves identical to untreated control cultures. The results of this study provide proof of concept for the use of macrophages as a delivery vector of NS into gliomas for photothermal ablation and open the possibility of developing such regimens for patient treatment
Restored Agricultural Wetlands in central Iowa: Habitat Quality and Amphibian Response
Amphibians are declining throughout the United States and worldwide due, partly, to habitat loss. Conservation practices on the landscape restore wetlands to denitrify tile drainage effluent and restore ecosystem services. Understanding how water quality, hydroperiod, predation, and disease affect amphibians in restored wetlands is central to maintaining healthy amphibian populations in the region. We examined the quality of amphibian habitat in restored wetlands relative to reference wetlands by comparing species richness, developmental stress, and adult leopard frog (Lithobates pipiens) survival probabilities to a suite of environmental metrics. Although measured habitat variables differed between restored and reference wetlands, differences appeared to have sub-lethal rather than lethal effects on resident amphibian populations. There were few differences in amphibian species richness and no difference in estimated survival probabilities between wetland types. Restored wetlands had more nitrate and alkaline pH, longer hydroperiods, and were deeper, whereas reference wetlands had more amphibian chytrid fungus zoospores in water samples and resident amphibians exhibited increased developmental stress. Restored and reference wetlands are both important components of the landscape in central Iowa and maintaining a complex of fish-free wetlands with a variety of hydroperiods will likely contribute to the persistence of amphibians in this landscape
Alpha and Persistence in Real Estate Fund Performance
Commercial real estate investment, Fund manager performance, R33, G11, G23,
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