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Buenos Aires, Argentina

Palermo A.M.,CITEDEF | Mudry M.D.,University of Buenos Aires
Current Drug Safety | Year: 2013

The standard version of the wing somatic mutation and recombination test (SMART) in Drosophila melanogaster was employed in order to evaluate the genotoxic potential of metronidazole (MTZ) as a function of exposure concentration. MTZ was administered by chronic feeding of 3-day-old larvae with the parenteral solution at 0, 500, 1000 and 2000 μg/ml until pupation. The marker-heterozygous progeny (mwh+/+flr3) with phenotypically wild-type wings was analyzed. Non significant differences were found between control and each MTZ concentration tested for single small spots (SSS) frequencies. Large single spots (LSS) and twin spots (TS) were significantly increased with the higher dose. MTZ treatments with 1000 and 2000 μg/ml also significantly increased the frequency of Total spots. These findings suggest that MTZ is genotoxic in the present experimental conditions and induces recombinagenesis and/or gene conversion, two major mechanisms that cause loss of heterocigosity and could play an important role in tumorigenesis and carcinogenesis processes. © 2013 Bentham Science Publishers. Source

Palermo A.M.,CITEDEF | Mudry M.D.,University of Buenos Aires | Mudry M.D.,CONICET
Mutation Research - Genetic Toxicology and Environmental Mutagenesis | Year: 2011

Isopropanol (isopropyl alcohol, 2-propanol, IPA) is a volatile solvent widely used in domestic or industrial environments and reported as innocuous in various test systems. The aim of this work was to search for in vivo genotoxic effects of IPA in Drosophila melanogaster, studying its ability to induce nondisjunction (ND) in females, sex linked recessive lethals (SLRL) in males, and somatic mutation and/or recombination (SMART) in larvae. Treatments were acute (60. min) and were administered via inhalation. IPA had low toxicity in adult flies (75% IPA mortality index, MI = 12.7% (females) and 2.6% (males)) and larvae (MI = 14.3%, 75% IPA). Female fertility was severely affected during the first 24 h (brood I, BI) after treatment, but, afterwards, control values were recovered. IPA induced a 50-fold increase of ND (%) in 24 h old females, and a six-fold rise in 4-5 d old BI offspring. Nondisjunction frequencies (%) in the offspring of broods II to V (24 h in each case) were similar to control values. IPA doses of 25% and 50% (v/v), tested in 24 h old females, showed a significant dose-dependent increase of ND(%)in BI only, with control values in subsequent broods. Flies gave normal offspring when kept in regular media for 24 h before mating. The eye spot test (SMART) showed a significant increase at 50% IPA (p<0.05, m = 2), but the response was not dose-dependent. IPA failed to induce SLRL in any of the spermatogenesis stages tested. These findings suggest that the main effect of IPA is to induce chromosomal malsegregation; IPA must be present at the resumption of M-phase I after fertilization, to exert these effects. The alcohol does not affect DNA directly, but perturbations of the nuclear membrane may be responsible for induction of ND. © 2011 Elsevier B.V. Source

Acuna L.M.,CITEDEF | Acuna L.M.,CONICET | Fuentes R.O.,Comision Nacional de la Energia Atomica | Fuentes R.O.,CONICET | And 3 more authors.
Journal of Physical Chemistry C | Year: 2014

In the present work, the local order of Zr in ZrO2-CeO 2 nanopowders (with 50, 65, 70, and 90 mol % CeO2) was studied by extended X-ray absorption fine structure around the Zr K-edge. In the cases of ZrO2-50 and 65 mol % CeO2, we studied how the local order is affected by the phase transition at high temperature. In order to study the tetragonal-cubic phase transition as a function of temperature, high-temperature synchrotron radiation X-ray powder diffraction (SR-XPD) was employed. We explored different models of the local atomic structure and interpreted them as distortions of the accepted long-range order deduced by XPD analyses. The results suggested the existence of distortions in the oxygen sublattice, which can be accounted for as displacements of the oxygen atoms along the (110) direction of the pseudofluorite unit cell that cannot be observed by XPD because of the random nature of these displacements. © 2014 American Chemical Society. Source

Prieto Gonzalez E.A.,Interamerican Open University | Mudry M.D.,University of Buenos Aires | Palermo A.M.,CITEDEF
Journal of Environmental Pathology, Toxicology and Oncology | Year: 2014

The objective of the present work was to study the fine kinetics of DNA repair in xeroderma pigmentosum (XP) syndrome, a complex disorder linked to a deficiency in repair that increases cancer susceptibility. The repair process was evaluated by the comet assay (CA) in cells from 2 XP patients and 9 controls exposed to UVA/B (UVA 366/UVB 280 nm) and H2O2(150 μM) at temperatures of 4, 15, and 37°C. Samples were taken at 2-min intervals during the first 10 min to analyze the “fine kinetics” repair during the initial phase of the curve, and then at 15, 20, 25, 30, 45, 60, and 120 min. CA evaluation of DNA repair activity points to BER/NER initiation in the first 30 min with both inductors at 37°C and 15°C, but final comet length showed differences according to treatment. Repair kinetics during 120 min showed a good correlation with clinical features in both XP patients. Differences in final comet length were less pronounced in XP cells treated with H2O2than with UVA/B, probably because the peroxide produces mainly base oxidation but less bulky lesions; UVA/B generates a mixture of both. These findings reinforce the value of CA in testing in DNA repair ability or exposure monitoring. © 2014 Begell House, Inc. Source

Nicora M.G.,CONICET | Quel E.J.,CONICET | Bali J.L.,CITEDEF | Acquesta A.,CITEDEF | And 4 more authors.
2015 International Symposium on Lightning Protection, XIII SIPDA 2015 | Year: 2015

This work presents a lightning jump algorithm (LJA): 'GeoRayos' to detect severe weather; it is based on the algorithm presented by Schultz et al. (2011) [1]. The lightning data used in this study came from the World Wide Lightning Location Network which is a real-time, world-wide and ground network. In this study, the lightning activity occurred during spring and summer of 2013 on the region [20-50]S of latitude and [50'70]W of longitude was examined. The LJA was validated by using information of severe weather occurrence in the report 'Estudio de los Tornados en la Rep. Argentina' this unpublished report (M. L. Altinger de Schwarzkopf, personal communication) provides severe phenomena occurred since 1930 to the present, also we used information from the National Weather Service in Argentina, local argentinean media, and radar data. The spatial and time distributions of lightning jumps were analyzed by using different spatial and temporal scales. © 2015 IEEE. Source

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