Anna Sannino

Lack of Genotoxic Effects (Micronucleus Induction) in Human Lymphocytes Exposed In Vitro to 900 MHz Electromagnetic Fields

Abstract Zeni, O., Schiavoni, A. S., Sannino, A., Antolini, A., Forigo, D., Bersani, F. and Scarfì, M. R. Lack of Genotoxic Effects (Micronucleus Induction) in Human Lymphocytes Exposed In Vitro to 900 MHz Electromagnetic Fields. Radiat. Res. 160, 152–158 (2003). In the present study, we investigated the induction of genotoxic effects in human peripheral blood lymphocytes after exposure to electromagnetic fields used in mobile communication systems (frequency 900 MHz). For this purpose, the incidence of micronuclei was evaluated by applying the cytokinesis-block micronucleus assay. Cytotoxicity was also investigated using the cytokinesis-block proliferation index. The experiments were performed on peripheral blood from 20 healthy donors, and several conditions were tested by varying the duration of exposure, the specific absorption rate (SAR), and the signal [continuous-wave (CW) or GSM (Global System of Mobile Communication) modulated signal]. The following exposures were carried out: (1) CW intermittent exposure (SAR = 1.6 W/kg) for 6 min followed by a 3-h pause (14 on/off cycles); (2) GSM signal, intermittent exposure as described in (1); (3) GSM signal, intermittent exposure as described in (1) 24 h before stimulation with phytohemagglutinin (8 on/off cycles); (4) GSM signal, intermittent exposure (SAR = 0.2 W/kg) 1 h per day for 3 days. The SARs were estimated numerically. No statistically significant differences were detected in any case in terms of either micronucleus frequency or cell cycle kinetics.

Exposure to Radiofrequency Radiation (900 MHz, GSM signal) does not Affect Micronucleus Frequency and Cell Proliferation in Human Peripheral Blood Lymphocytes: An Interlaboratory Study

Abstract Scarfì, M. R., Fresegna, A. M., Villani, P., Pinto, R., Marino, C., Sarti, M., Altavista, P., Sannino, A. and Lovisolo, G. A. Exposure to Radiofrequency Radiation (900 MHz, GSM signal) does not Affect Micronucleus Frequency and Cell Proliferation in Human Peripheral Blood Lymphocytes: An Interlaboratory Study. Radiat. Res. 165, 655–663 (2006). The objective of this study was to investigate whether 24 h exposure to radiofrequency electromagnetic fields similar to those emitted by mobile phones induces genotoxic effects and/or effects on cell cycle kinetics in cultured human peripheral blood lymphocytes. The effect of 900 MHz exposure (GSM signal) was evaluated at four specific absorption rates (SARs, 0, 1, 5 and 10 W/kg peak values). The exposures were carried out in wire patch cells under strictly controlled conditions of both temperature and dosimetry, and the induction of genotoxic effects was evaluated in lymphocyte cultures from 10 healthy donors by applying the cytokinesis-block micronucleus assay. Positive controls were provided by using mitomycin C. Two research groups were involved in the study, one at ENEA, Rome, and the other at CNR-IREA, Naples. Each laboratory tested five donors, and the resulting slides were scored by both laboratories. Following this experimental scheme, it was also possible to compare the results obtained by cross-scoring of slides. The results obtained provided no evidence for the existence of genotoxic or cytotoxic effects in the range of SARs investigated. These findings were confirmed in the two groups of five donors examined in the two laboratories and when the same slides were scored by two operators.

Induction of Adaptive Response in Human Blood Lymphocytes Exposed to Radiofrequency Radiation

Abstract Sannino, A., Sarti, M., Reddy, S. B., Prihoda, T. J., Vijayalaxmi and Scarfì, M. R. Induction of Adaptive Response in Human Blood Lymphocytes Exposed to Radiofrequency Radiation. Radiat. Res. 171, 735–742 (2009). The incidence of micronuclei was evaluated to assess the induction of an adaptive response to non-ionizing radiofrequency (RF) radiation in peripheral blood lymphocytes collected from five different human volunteers. After stimulation with phytohemagglutinin for 24 h, the cells were exposed to an adaptive dose of 900 MHz RF radiation used for mobile communications (at a peak specific absorption rate of 10 W/kg) for 20 h and then challenged with a single genotoxic dose of mitomycin C (100 ng/ml) at 48 h. Lymphocytes were collected at 72 h to examine the frequency of micronuclei in cytokinesis-blocked binucleated cells. Cells collected from four donors exhibited the induction of adaptive response (i.e., responders). Lymphocytes that were pre-exposed to 900 MHz RF radiation had a significantly decreased incidence of micronuclei induced by the challenge dose of mitomycin C compared to those that were not pre-exposed to 900 MHz RF radiation. These preliminary results suggested that the adaptive response can be induced in cells exposed to non-ionizing radiation. A similar phenomenon has been reported in cells as well as in animals exposed to ionizing radiation in several earlier studies. However, induction of adaptive response was not observed in the remaining donor (i.e., non-responder). The incidence of micronuclei induced by the challenge dose of mitomycin C was not significantly different between the cells that were pre-exposed and unexposed to 900 MHz RF radiation. Thus the overall data indicated the existence of heterogeneity in the induction of an adaptive response between individuals exposed to RF radiation and showed that the less time-consuming micronucleus assay can be used to determine whether an individual is a responder or non-responder.

Impact of postoperative acute kidney injury on clinical outcomes after transcatheter aortic valve implantation: A meta-analysis of 5,971 patients

There is conflicting evidence on the safety and efficacy of transcatheter aortic valve implantation (TAVI) in patients with postoperative acute kidney injury (AKI). Therefore, we conducted a meta‐analysis on the impact of AKI on clinical outcomes after TAVI.

Moderate and Severe Preoperative Chronic Kidney Disease Worsen Clinical Outcomes After Transcatheter Aortic Valve Implantation Meta-Analysis of 4992 Patients

Background—There is a conflicting evidence on safety and efficacy of transcatheter aortic valve implantation in patients with preoperative chronic kidney disease (CKD). Therefore, we conducted a meta-analysis on the impact of CKD on outcomes after transcatheter aortic valve implantation. Methods and Results—Nine studies including 4992 patients were analyzed. Overall preoperative CKD (stages 3–5) significantly increased early (odds ratio [OR], 1.44; 95% confidence interval [CI], 1.08–1.94 and OR, 1.66; 95% CI, 1.04–2.67) and 1-year (OR, 1.66; 95% CI, 1.23–2.25 and OR, 1.32; 95% CI, 1.06–1.63) all-cause and cardiovascular mortality, respectively. Moderate CKD (stage 3) alone also increased early and 1-year all-cause mortality (OR, 1.43; 95% CI, 1.10–1.85 and OR, 1.41; 95% CI, 1.13–1.74). CKD stages 4 to 5 and 3 compared with stages 1 to 2 increased early stroke (OR, 2.67; 95% CI, 1.53–4.65 and OR, 1.66; 95% CI, 1.09–2.52), acute kidney injury (OR, 2.09; 95% CI, 1.17–3.72 and OR, 1.32; 95% CI, 1.09–1.60) and need for dialysis (OR, 5.92; 95% CI, 2.46–14.27 and OR, 1.55; 95% CI, 0.65–3.70), in the absence of significant differences in contrast medium administration (mean difference, −26.07; 95% CI, −53.00 to 0.85 and mean difference, −0.42; 95% CI, −16.10 to 15.26). Bleeding (life-threatening or major) was nonsignificantly increased in CKD 3 to 5 compared with CKD 1 to 2, but significantly increased in most severe patients (CKD 4–5 versus CKD 1–2: OR, 1.66; 95% CI, 1.13–2.44; CKD 4–5 versus CKD 3: OR, 1.68; 95% CI, 1.27–2.24). Conclusions—Both moderate and severe preoperative CKD significantly worsen transcatheter aortic valve implantation prognosis. Future studies on risk evaluation, prevention, and postoperative management are needed.

INDUCTION OF AN ADAPTIVE RESPONSE IN HUMAN BLOOD LYMPHOCYTES EXPOSED TO RADIOFREQUENCY FIELDS: INFLUENCE OF THE UNIVERSAL MOBILE TELECOMMUNICATION SYSTEM (UMTS) SIGNAL AND THE SPECIFIC ABSORPTION RATE

The induction of an adaptive response (AR) was examined in human peripheral blood lymphocytes exposed to non-ionizing radiofrequency fields (RF). Cells from nine healthy human volunteers were stimulated for 24h with phytohaemagglutinin and then exposed for 20h to an adaptive dose (AD) of a 1950MHz RF UMTS (universal mobile telecommunication system) signal used for mobile communications, at different specific absorption rates (SAR) of 1.25, 0.6, 0.3, and 0.15W/kg. This was followed by treatment of the cells at 48h with a challenge dose (CD) of 100ng/ml mitomycin C (MMC). Lymphocytes were collected at the end of the 72h total culture period. The cytokinesis-block method was used to record the frequency of micronuclei (MN) as genotoxicity end-point. When lymphocytes from six donors were pre-exposed to RF at 0.3W/kg SAR and then treated with MMC, these cells showed a significant reduction in the frequency of MN, compared with the cells treated with MMC alone; this result is indicative of induction of AR. The results from our earlier study indicated that lymphocytes that were stimulated for 24h, exposed for 20h to a 900MHz RF GSM (global system for mobile communication) signal at 1.25W/kg SAR and then treated with 100ng/ml MMC, also exhibited AR. These overall data suggest that the induction of AR depends on RF frequency, type of the signal and SAR. Further characterization of RF-induced AR is in progress.

Evaluation of Genotoxic Effects in Human Fibroblasts after Intermittent Exposure to 50 Hz Electromagnetic Fields: A Confirmatory Study

Abstract Scarfí, M. R., Sannino, A., Perrotta, A., Sarti, M., Mesirca, P. and Bersani, F. Evaluation of Genotoxic Effects in Human Fibroblasts after Intermittent Exposure to 50 Hz Electromagnetic Fields: A Confirmatory Study. Radiat. Res. 164, 270–276 (2005). The aim of this investigation was to confirm the main results reported in recent studies on the induction of genotoxic effects in human fibroblasts exposed to 50 Hz intermittent (5 min field on/10 min field off) sinusoidal electromagnetic fields. For this purpose, the induction of DNA single-strand breaks was evaluated by applying the alkaline single-cell gel electrophoresis (SCGE)/comet assay. To extend the study and validate the results, in the same experimental conditions, the potential genotoxicity was also tested by exposing the cells to a 50 Hz powerline signal (50 Hz frequency plus its harmonics). The cytokinesis-block micronucleus assay was applied after 24 h intermittent exposure to both sinusoidal and powerline signals to obtain information on cell cycle kinetics. The experiments were carried out on human diploid fibroblasts (ES-1). For each experimental run, exposed and sham-exposed samples were set up; positive controls were also provided by treating cells with hydrogen peroxide or mitomycin C for the comet or micronucleus assay, respectively. No statistically significant difference was detected in exposed compared to sham-exposed samples in any of the experimental conditions tested (P > 0.05). In contrast, the positive controls showed a statistically significant increase in DNA damage in all cases, as expected. Accordingly, our findings do not confirm the results reported previously for either comet induction or an increase in micronucleus frequency.

Induction of adaptive response in human blood lymphocytes exposed to 900 MHz radiofrequency fields: Influence of cell cycle

Abstract Purpose: To investigate the influence of cell cycle on the adaptive response (AR) induced by the exposure of human blood lymphocytes to radiofrequency fields (RF). Materials and methods: Human peripheral blood lymphocytes in G0-, G1- or S-phase of the cell cycle were exposed for 20 hours to an adaptive dose (AD) of 900 MHz RF at an average specific absorption rate of 1.25 W/kg and then treated with a challenge dose (CD) of 100 ng/ml mitomycin C (MMC). Un-exposed and sham-exposed controls as well as cells treated with MMC alone were included in the study. The incidence of micronuclei (MN) was evaluated to determine the induction of AR. Results: The results indicated that the cells which were exposed to AD of RF in G0- and G1-phase of the cell cycle did not exhibit AR while such a response was observed when the cells were exposed to AD of RF in S-phase of the cell cycle. Conclusions: These results confirmed the observations reported in our previous investigation where AR was observed in human blood lymphocytes exposed to AD of RF in S-phase of the cell cycle and further suggested that the timing of AD exposure of RF is important to elicit AR.

Genetic Deletion of Uncoupling Protein 3 Exaggerates Apoptotic Cell Death in the Ischemic Heart Leading to Heart Failure

Background Uncoupling protein 3 (ucp3) is a member of the mitochondrial anion carrier superfamily of proteins uncoupling mitochondrial respiration. In this study, we investigated the effects of ucp3 genetic deletion on mitochondrial function and cell survival under low oxygen conditions in vitro and in vivo. Methods and Results To test the effects of ucp3 deletion in vitro, murine embryonic fibroblasts and adult cardiomyocytes were isolated from wild‐type (WT, n=67) and ucp3 knockout mice (ucp3−/−, n=70). To test the effects of ucp3 genetic deletion in vivo, myocardial infarction (MI) was induced by permanent coronary artery ligation in WT and ucp3−/− mice. Compared with WT, ucp3−/− murine embryonic fibroblasts and cardiomyocytes exhibited mitochondrial dysfunction and increased mitochondrial reactive oxygen species generation and apoptotic cell death under hypoxic conditions in vitro (terminal deoxynucleotidyl transferase‐dUTP nick end labeling–positive nuclei: WT hypoxia, 70.3±1.2%; ucp3−/− hypoxia, 85.3±0.9%; P<0.05). After MI, despite similar areas at risk in the 2 groups, ucp3−/− hearts demonstrated a significantly larger infarct size compared with WT (infarct area/area at risk: WT, 48.2±3.7%; ucp3−/−, 65.0±2.9%; P<0.05). Eight weeks after MI, cardiac function was significantly decreased in ucp3−/− mice compared with WT (fractional shortening: WT MI, 42.7±3.1%; ucp3−/− MI, 24.4±2.9; P<0.05), and this was associated with heightened apoptotic cell death (terminal deoxynucleotidyl transferase‐dUTP nick end labeling–positive nuclei: WT MI, 0.7±0.04%; ucp3−/− MI, 1.1±0.09%, P<0.05). Conclusions Our data indicate that ucp3 levels regulate reactive oxygen species levels and cell survival during hypoxia, modulating infarct size in the ischemic heart.

Adaptive response in human blood lymphocytes exposed to non-ionizing radiofrequency fields: resistance to ionizing radiation-induced damage

The aim of this preliminary investigation was to assess whether human peripheral blood lymphocytes which have been pre-exposed to non-ionizing radiofrequency fields exhibit an adaptive response (AR) by resisting the induction of genetic damage from subsequent exposure to ionizing radiation. Peripheral blood lymphocytes from four healthy donors were stimulated with phytohemagglutinin for 24 h and then exposed for 20 h to 1950 MHz radiofrequency fields (RF, adaptive dose, AD) at an average specific absorption rate of 0.3 W/kg. At 48 h, the cells were subjected to a challenge dose (CD) of 1.0 or 1.5 Gy X-irradiation (XR, challenge dose, CD). After a 72 h total culture period, cells were collected to examine the incidence of micronuclei (MN). There was a significant decrease in the number of MN in lymphocytes exposed to RF + XR (AD + CD) as compared with those subjected to XR alone (CD). These observations thus suggested a RF-induced AR and induction of resistance to subsequent damage from XR. There was variability between the donors in RF-induced AR. The data reported in our earlier investigations also indicated a similar induction of AR in human blood lymphocytes that had been pre-exposed to RF (AD) and subsequently treated with a chemical mutagen, mitomycin C (CD). Since XR and mitomycin-C induce different kinds of lesions in cellular DNA, further studies are required to understand the mechanism(s) involved in the RF-induced adaptive response.