Search results for "Low dose"
showing 10 items of 66 documents
Comparison of time and dose dependent gene expression and affected pathways in primary human fibroblasts after exposure to ionizing radiation
2020
Abstract Background Exposure to ionizing radiation induces complex stress responses in cells, which can lead to adverse health effects such as cancer. Although a variety of studies investigated gene expression and affected pathways in human fibroblasts after exposure to ionizing radiation, the understanding of underlying mechanisms and biological effects is still incomplete due to different experimental settings and small sample sizes. Therefore, this study aims to identify the time point with the highest number of differentially expressed genes and corresponding pathways in primary human fibroblasts after irradiation at two preselected time points. Methods Fibroblasts from skin biopsies of…
2019
PIK3CA-related overgrowth spectrum (PROS) encompasses a range of debilitating conditions defined by asymmetric overgrowth caused by mosaic activating PIK3CA variants. PIK3CA encodes the p110α catalytic subunit of phosphatidylinositol-3-kinase (PI3K), a critical transducer of growth factor signaling. As mTOR mediates the growth-promoting actions of PI3K, we hypothesized that the mTOR inhibitor sirolimus would slow pathological overgrowth. Thirty-nine participants with PROS and progressive overgrowth were enrolled into open-label studies across three centers, and results were pooled. For the primary outcome, tissue volumes at affected and unaffected sites were measured by dual energy X-ray ab…
Stone-Free Rate after Treating Kidney Stones Exceeding 10 mm via Flexible Ureteroscopy: Can Endoscopic Assessment Replace Low-Dose Computed Tomograph…
2019
<b><i>Introduction:</i></b> It is unclear whether endoscopic assessment of the stone-free rate after flexible ureteroscopy (fURS) is as effective as assessment with low-dose computed tomography (CT) scan. <b><i>Methods:</i></b> Prospective documentation of patients with kidney stones &#x3e; 10 mm diameter from 2 different centers (Freiburg, Regensburg), who underwent fURS and were declared to be endoscopically completely stone-free. Low-dose CT control performed 4–8 weeks postoperatively. <b><i>Results/Conclusion:</i></b> Thirty-eight patients were treated between October 2015 and August 2016 (12 F, 26 M). Average a…
Blue-yellow deficiency in workers exposed to low concentrations of organic solvents
1997
Objectives: To evaluate the effects of low concentrations of organic solvents on color vision. Methods: Color vision was examined in 24 workers exposed to mixtures of solvents and in 24 control subjects. Exposure to mixtures was below the threshold-limit values. Color vision ability was assessed using the Ishihara plates (to screen for congenital dyschromatopsia), the Farnsworth panel D-15 test, the Lanthony desaturated panel D-15 test, and the Standard Pseudoisochromatic Plates part 2 (SPP2 test). Results: The comparatively less sensitive Farnsworth panel D-15 test failed to show any difference between the groups, but the Lanthony panel D-15 desaturated test as well as the SPP2 test showed…
The effect of two low doses of aspirin on whole blood thromboxane and prostacyclin generation in healthy subjects
1983
SummaryThe effects of two low doses of aspirin (20 mg and 100 mg) on prostacyclin and thromboxane formation during whole blood clotting were studied in 8 healthy volunteers.A single 100 mg aspirin dose caused more than 90% reduction of both serum TXB2 and 6-keto-PGF1α; a single 20 mg dose of aspirin inhibited serum TXB2 more than 6-keto-PGF1α but effects on these two products could not be completely dissociated.However, the effect of a single 20 mg aspirin dose on serum TXB2, was of much longer duration than its inhibitory effect on PGI2 synthesis during whole blood clotting.
Unruptured tubal pregnancy: local low-dose therapy with methotrexate under transvaginal ultrasonographic guidance.
1996
Thirty patients with unruptured ectopic pregnancy (4-10 weeks' gestation) were treated locally with methotrexate (MTX) under sonographic guidance. The transvaginal puncture was performed under analgesic sedation using an automatic puncturing device. Local MTX therapy was successful in 25 patients (83.3%). Eighteen of these patients had received a single MTX instillation with a total dose of 10 mg, 7 patients had received a second instillation with 10 mg because of plateauing hCG levels after the first instillation. In 5 patients MTX therapy was unsuccessful. Surgical intervention was necessary within 4 h to 15 days after MTX treatment, due to severe tubal bleeding (n = 1) or the development…
Healthy ageing and Mediterranean diet: A focus on hormetic phytochemicals
2021
Abstract Mediterranean diet (MedDiet) is rich in fruits and vegetables associated with longevity and a reduced risk of several age-related diseases. It is demonstrated that phytochemicals in these plant products enhance the positive effects of MedDiet by acting on the inflammatory state and reducing oxidative stress. Evidence support that these natural compounds act as hormetins, triggering one or more adaptive stress-response pathways at low doses. Activated stress-response pathways increase the expression of cytoprotective proteins and multiple genes that act as lifespan regulators, essential for the ageing process. In these ways, the hormetic response by phytochemicals such as resveratro…
Assessment of mechanisms driving non-linear dose-response relationships in genotoxicity testing.
2014
In genetic toxicology, risk assessment has traditionally adopted linear dose-responses for any compound that causes genotoxic effects. Increasing evidence of non-linear dose-responses, however, suggests potential cellular tolerance to low levels of many genotoxicants with diverse modes of action. Such putative non-linear dose-responses need to be substantiated by strong mechanistic data that identifies the mechanisms responsible for the tolerance to low doses. This can be achieved by experimental demonstration of cytoprotective mechanisms and by providing experimental support for the existence of tolerance mechanisms against low dose effects. By highlighting key experiments into low dose me…
Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead
2015
Goodson, William H. et al.
The prevalence and characteristics of breakthrough cancer pain in patients receiving low doses of opioids for background pain
2021
Simple Summary The aim of this study was to assess the prevalence and characteristics of breakthrough cancer pain (BTcP) in patients receiving low doses of opioids for background pain. This prospective study showed that in this population, BTcP prevalence was 69.8%. Many patients did not achieve a sufficient level of satisfaction with BTcP medications, particularly with oral morphine. Data also suggest that better optimization of background analgesia, though apparently acceptable, may limit the number of BTcP episodes. Abstract The aim of this study was to assess the prevalence and characteristics of breakthrough cancer pain (BTcP) in patients receiving low doses of opioids for background p…