Search results for " Ionizing"

Lovastatin protects human endothelial cells from killing by ionizing radiation without impairing induction and repair of DNA double-strand breaks.

2006

Abstract Purpose: 3-hydroxy-3-methylglutaryl CoA reductase inhibitors (statins) are frequently used lipid-lowering drugs. Moreover, they are reported to exert pleiotropic effects on cellular stress responses, proliferation, and apoptosis. Whether statins affect the sensitivity of primary human cells to ionizing radiation (IR) is still unknown. The present study aims at answering this question. Experimental Design: The effect of lovastatin on IR-provoked cytotoxicity was analyzed in primary human umbilical vein endothelial cells (HUVEC). To this end, cell viability, proliferation, and apoptosis as well as DNA damage–related stress responses were investigated. Results: The data show that lova…

PROPERTIES OF IONIZING RADIATION CURED POLYMER MATRICES FOR CARBON FIBER COMPOSITES AFTER AGEING DUE TO MOISTURE ABSORPTION AND THERMAL TREATMENT

2008

Micronucleus frequencies and clonogenic cell survival in TK6 cells exposed to changing dose rates under controlled temperature conditions.

2014

In most exposure scenarios the dose rate of exposure is not constant. Despite this, very little information exists on the possible biological effects of exposing cells to radiation under the conditions of a changing dose rate. The current study highlights interesting effects following exposure under these conditions.We constructed a new exposure facility that allows exposing cells inside an incubator and used it to irradiate human lymphoblastoid TK6 cells both after a moderate (0.48 Gy) and a high (1.1 Gy) dose, where the change in dose rate was, respectively, ≈ 17-fold (2.2-37 mGy/min) and ≈ 39-fold (2.7-106 mGy/min). Clonogenic survival and micronuclei (MN) induction were the chosen endpo…

DNA damage-induced cell death: From specific DNA lesions to the DNA damage response and apoptosis

2011

DNA damaging agents are potent inducers of cell death triggered by apoptosis. Since these agents induce a plethora of different DNA lesions, it is firstly important to identify the specific lesions responsible for initiating apoptosis before the apoptotic executing pathways can be elucidated. Here, we describe specific DNA lesions that have been identified as apoptosis triggers, their repair and the signaling provoked by them. We discuss methylating agents such as temozolomide, ionizing radiation and cisplatin, all of them are important in cancer therapy. We show that the potentially lethal events for the cell are O(6)-methylguanine adducts that are converted by mismatch repair into DNA dou…

The "Livio Scarsi" X-Ray Facility at University of Palermo for Device Testing

2015

In this work, we report on the characteristics of the Livio Scarsi X-ray facility at University of Palermo. The facility is able to produce low energy X rays, within the energy range of 0.1-60 keV, with fluence rates ranging from 105-108 photons/mm2 s. The laboratory is equipped with an innovative digital detection system, based on semiconductor detectors (Si and CdTe detectors), able to provide accurate and precise estimation of the fluence rate, the energy and the exposure of X rays, even at high counting rate conditions. Instrumentation for electrical characterization (DC-AC) of semiconductor devices, for both off-line and on-line (i.e. during the irradiation) measurements, is also avail…

Search for magnetic monopoles with the MoEDAL prototype trapping detector in 8 TeV proton-proton collisions at the LHC

2016

The MoEDAL experiment is designed to search for magnetic monopoles and other highly-ionising particles produced in high-energy collisions at the LHC. The largely passive MoEDAL detector, deployed at Interaction Point 8 on the LHC ring, relies on two dedicated direct detection techniques. The first technique is based on stacks of nuclear-track detectors with surface area $\sim$18 m$^2$, sensitive to particle ionisation exceeding a high threshold. These detectors are analysed offline by optical scanning microscopes. The second technique is based on the trapping of charged particles in an array of roughly 800 kg of aluminium samples. These samples are monitored offline for the presence of trap…

DNA double-strand breaks trigger apoptosis in p53-deficient fibroblasts

2001

DNA double-strand breaks (DSBs) are induced by ionizing radiation (IR) and various radiomimetic agents directly, or indirectly as a consequence of DNA repair, recombination and replication of damaged DNA. They are ultimately involved in the generation of chromosomal aberrations and were reported to cause genomic instability, gene amplification and reproductive cell death. To address the question of whether DSBs act as a trigger of apoptosis, we induced DSBs by means of restriction enzyme electroporation and compared the effect with IR in mouse fibroblasts that differ in p53 status [wild-type (+/+) versus p53-deficient (-/-) cells]. We show that (i) electroporation of PVU:II is highly effici…

A comparison of the transcriptome of Drosophila melanogaster in response to entomopathogenic fungus, ionizing radiation, starvation and cold shock

2015

Background The molecular mechanisms that determine the organism's response to a variety of doses and modalities of stress factors are not well understood. Results We studied effects of ionizing radiation (144, 360 and 864 Gy), entomopathogenic fungus (10 and 100 CFU), starvation (16 h), and cold shock (+4, 0 and -4°C) on an organism's viability indicators (survival and locomotor activity) and transcriptome changes in the Drosophila melanogaster model. All stress factors but cold shock resulted in a decrease of lifespan proportional to the dose of treatment. However, stress-factors affected locomotor activity without correlation with lifespan. Our data revealed both significant similarities …

Search for Magnetic Monopoles with the MoEDAL Forward Trapping Detector in 13 TeV Proton-Proton Collisions at the LHC

2017

MoEDAL is designed to identify new physics in the form of long-lived highly-ionising particles produced in high-energy LHC collisions. Its arrays of plastic nuclear-track detectors and aluminium trapping volumes provide two independent passive detection techniques. We present here the results of a first search for magnetic monopole production in 13 TeV proton-proton collisions using the trapping technique, extending a previous publication with 8 TeV data during LHC run-1. A total of 222 kg of MoEDAL trapping detector samples was exposed in the forward region and analysed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges excee…

Nose-to-brain delivery of insulin enhanced by a nanogel carrier.

2018

Recent evidences suggest that insulin delivery to the brain can be an important pharmacological therapy for some neurodegenerative pathologies, including Alzheimer disease (AD). Due to the presence of the Blood Brain Barrier, a suitable carrier and an appropriate route of administration are required to increase the efficacy and safety of the treatment. Here, poly(N-vinyl pyrrolidone)-based nanogels (NG), synthetized by e-beam irradiation, alone and with covalently attached insulin (NG-In) were characterized for biocompatibility and brain delivery features in a mouse model. Preliminarily, the biodistribution of the "empty" nanocarrier after intraperitoneal (i.p.) injection was investigated b…