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Rebuzzini P.,University of Pavia | Fassina L.,University of Pavia | Mulas F.,University of Pavia | Bellazzi R.,University of Pavia | And 7 more authors.
Mutation Research - Genetic Toxicology and Environmental Mutagenesis | Year: 2013

Embryonic stem cells (ESCs) for their derivation from the inner cell mass of a blastocyst represent a valuable in vitro model to investigate the effects of ionizing radiation on early embryonic cellular response. Following irradiation, both human and mouse ESCs (mESCs) maintain their pluripotent status and the capacity to differentiate into embryoid bodies and to form teratomas. Although informative of the maintenance of a pluripotent status, these studies never investigated the capability of irradiated ESCs to form specific differentiated phenotypes. Here, for the first time, 5. Gy-irradiated mESCs were differentiated into cardiomyocytes, thus allowing the analysis of the long-term effects of ionizing radiations on the differentiation potential of a pluripotent stem cell population. On treated mESCs, 96. h after irradiation, a genome-wide expression analysis was first performed in order to determine whether the treatment influenced gene expression of the surviving mESCs. Microarrays analysis showed that only 186 genes were differentially expressed in treated mESCs compared to control cells; a quarter of these genes were involved in cellular differentiation, with three main gene networks emerging, including cardiogenesis. Based on these results, we differentiated irradiated mESCs into cardiomyocytes. On day 5, 8 and 12 of differentiation, treated cells showed a significant alteration (qRT-PCR) of the expression of marker genes (Gata-4, Nkx-2.5, Tnnc1 and Alpk3) when compared to control cells. At day 15 of differentiation, although the organization of sarcomeric α-actinin and troponin T proteins appeared similar in cardiomyocytes differentiated from either mock or treated cells, the video evaluation of the kinematics and dynamics of the beating cardiac syncytium evidenced altered contractile properties of cardiomyocytes derived from irradiated mESCs. This alteration correlated with significant reduction of Connexin 43 foci. Our results indicate that mESCs populations that survive an ionizing irradiation treatment are capable to differentiate into cardiomyocytes, but they have altered contractile properties. © 2013 Elsevier B.V. Source


Mowlavi A.A.,Hakim Sabzevari University | Fornasier M.R.,Science di Fisica Sanitaria | Mirzaei M.,Chamran Institute of Technology | Bregant P.,Science di Fisica Sanitaria | de Denaro M.,Science di Fisica Sanitaria
Annals of Nuclear Medicine | Year: 2014

Background: The beta and gamma absorbed fractions in organs and tissues are the important key factors of radionuclide internal dosimetry based on Medical Internal Radiation Dose (MIRD) approach.Objectives: The aim of this study is to find suitable analytical functions for beta and gamma absorbed fractions in spherical and ellipsoidal volumes with a uniform distribution of iodine-131 radionuclide.Methods: MCNPX code has been used to calculate the energy absorption from beta and gamma rays of iodine-131 uniformly distributed inside different ellipsoids and spheres, and then the absorbed fractions have been evaluated.Results: We have found the fit parameters of a suitable analytical function for the beta absorbed fraction, depending on a generalized radius for ellipsoid based on the radius of sphere, and a linear fit function for the gamma absorbed fraction.Conclusion: The analytical functions that we obtained from fitting process in Monte Carlo data can be used for obtaining the absorbed fractions of iodine-131 beta and gamma rays for any volume of the thyroid lobe. Moreover, our results for the spheres are in good agreement with the results of MIRD and other scientific literatures. © 2014, The Japanese Society of Nuclear Medicine. Source


Rebuzzini P.,University of Pavia | Pignalosa D.,Helmholtz Center for Heavy Ion Research | Mazzini G.,CNR Institute of Molecular Genetics | Di Liberto R.,Science di Fisica Sanitaria | And 6 more authors.
Journal of Cellular Physiology | Year: 2012

This study aimed to investigate the cell cycle, apoptosis, cytogenetics and differentiation capacity of mouse embryonic stem cells (mESCs) that survived a single dose of 2 or 5Gy γ-rays during a period of up to 96h of culture. After 2Gy irradiation and 24h culture, compared to control, a significant majority of cells was blocked at the G2/M phase and a massive apoptosis was recorded. Between 48 and 72h post-irradiation, the parameters used to describe the cell cycle and apoptosis returned similar to those of control samples. When mESCs were irradiated with 5Gy, a small fraction of cells, even after 96h of culture, still presented clear evidences of a G2/M block and apoptosis. The cytogenetic analysis performed at 96h showed that the structural stability of the aberrations did not change significantly when comparing control and 2 or 5Gy-treated populations. However, the chromosomal damage observed in the progeny of the survived cells after 5Gy exposure is significantly higher than that observed in control samples, although it is mostly of the stable and transmissible type. Ninety-six hours after irradiation, the survived mESCs maintained their undifferentiated status and capability to differentiate into the three germ layers. Overall, these results indicate a commitment of mESCs to maintain pluripotency and genome stability. © 2011 Wiley Periodicals, Inc. Source


Mowlavi A.A.,Kharazmi University | Fornasier M.R.,Science di Fisica Sanitaria | Binesh A.,Payam Nour University | Denaro M.D.,Science di Fisica Sanitaria
Environmental Monitoring and Assessment | Year: 2012

Environmental monitoring and indoor radon measurement are important for public health, to estimate the cancer risk of respiratory system and, if necessary, to suggest proper methods that reduce indoor radon level. In this research, indoor radon concentration in the air has been measured in 150 apartments in Mashhad city. The result demonstrates about 94.7% of apartments have radon concentration less than 100 Bq/m 3, taken by WHO as the action level, and 5.3% have the concentration higher than this level. As well as, annual radon dose has been assessed using the equation for annual effective dose calculation introduced by United Nations Scientific Committee on the Effects of Atomic Radiation. © 2011 Springer Science+Business Media B.V. Source


Asghar Mowlavi A.,Science di Fisica Sanitaria | Asghar Mowlavi A.,Kharazmi University | Rosa Fornasie Maria M.,Science di Fisica Sanitaria | de Denaro Mario M.,Science di Fisica Sanitaria
Applied Radiation and Isotopes | Year: 2011

In this study, the MCNPX code has been used to simulate a proton therapy in thyroid gland, in order to calculate the proton energy deposition in the target region. As well as, we have calculated the photon and neutron production spectra due to proton interactions with the tissue. We have considered all the layers of tissue, from the skin to the thyroid gland, and an incident high energy pencil proton beam. The results of the simulation show that the best proton energy interval, to cover completely the thyroid tissue, is from 42 to 54. MeV, assuming that the thyroid gland has a 14. mm thickness and is located 11.2. mm under the skin surface. The most percentage of deposited energy (78%) is related to the 54. MeV proton energy beam. Total photon and neutron production are linear and polynomial second order functions of the proton energy, respectively. © 2010 Elsevier Ltd. Source

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