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Albendary M, Mohamedahmed AYY, Alamin A, Rout S, George A, Zaman S. Efficacy and safety of mesh closure in preventing wound failure following emergency laparotomy: a systematic review and meta-analysis. Langenbecks Arch Surg 2022; 407:1333-1344. [PMID: 35020082 DOI: 10.1007/s00423-021-02421-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 12/20/2021] [Indexed: 11/29/2022]
Abstract
AIMS To evaluate comparative outcomes of emergency laparotomy closure with and without prophylactic mesh. METHODS A systematic review was performed via literature databases: PubMed, Cochrane Library, Science Direct, and Google Scholar. Studies were examined for eligibility and included if they compared prophylactic mesh closure to the conventional laparotomy closure following emergency abdominal surgery. Both acute wound failure and incisional hernia (IH) occurence were our primary outcomes. Secondary outcomes included surgical site infection (SSI), seroma/hematoma formation, Clavien-Dindo complications (score ≥ 3), total operative time, and length of hospital stay (LOS). RESULTS Two randomised controlled trials (RCTs) and four comparative studies with a total of 817 patients met the inclusion criteria. Overall acute wound failure and incisional hernia rate was significantly lower in the mesh group compared to non-mesh group (odd ratio (OR) 0.23, p = 0.002) and (OR 0.21, p = 0.00001), respectively. There was no significant difference between the two groups regarding the following outcomes: total operative time (mean difference (MD) 21.44, p = 0.15), SSI (OR 1.47, p = 0.06), seroma/haematoma formation (OR 2.74, p = 0.07), grade ≥ 3 Clavien-Dindo complications (OR 2.39, p = 0.28), and LOS (MD 0.26, p = 0.84). CONCLUSION The current evidence for the use of prophylactic mesh in emergency laparotomy is diverse and obscure. Although the data trends towards a reduction in the incidence of IH, a reliable conclusion requires further high-quality RCTs to fully assess the efficacy and safety of mesh use in an emergency setting.
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Affiliation(s)
- Mohamed Albendary
- Department of General Surgery, Sandwell and West, Birmingham Hospitals NHS Trust, Birmingham, UK
| | - Ali Yasen Y Mohamedahmed
- Department of General Surgery, Sandwell and West, Birmingham Hospitals NHS Trust, Birmingham, UK.
| | | | - Shantanu Rout
- Department of General Surgery, Sandwell and West, Birmingham Hospitals NHS Trust, Birmingham, UK
| | - Anil George
- Department of General Surgery, Sandwell and West, Birmingham Hospitals NHS Trust, Birmingham, UK
| | - Shafquat Zaman
- Department of General Surgery, Sandwell and West, Birmingham Hospitals NHS Trust, Birmingham, UK
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2
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Postoperative acute kidney injury in adult non-cardiac surgery: joint consensus report of the Acute Disease Quality Initiative and PeriOperative Quality Initiative. Nat Rev Nephrol 2021; 17:605-618. [PMID: 33976395 PMCID: PMC8367817 DOI: 10.1038/s41581-021-00418-2] [Citation(s) in RCA: 88] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/17/2021] [Indexed: 02/03/2023]
Abstract
Postoperative acute kidney injury (PO-AKI) is a common complication of major surgery that is strongly associated with short-term surgical complications and long-term adverse outcomes, including increased risk of chronic kidney disease, cardiovascular events and death. Risk factors for PO-AKI include older age and comorbid diseases such as chronic kidney disease and diabetes mellitus. PO-AKI is best defined as AKI occurring within 7 days of an operative intervention using the Kidney Disease Improving Global Outcomes (KDIGO) definition of AKI; however, additional prognostic information may be gained from detailed clinical assessment and other diagnostic investigations in the form of a focused kidney health assessment (KHA). Prevention of PO-AKI is largely based on identification of high baseline risk, monitoring and reduction of nephrotoxic insults, whereas treatment involves the application of a bundle of interventions to avoid secondary kidney injury and mitigate the severity of AKI. As PO-AKI is strongly associated with long-term adverse outcomes, some form of follow-up KHA is essential; however, the form and location of this will be dictated by the nature and severity of the AKI. In this Consensus Statement, we provide graded recommendations for AKI after non-cardiac surgery and highlight priorities for future research.
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Elmore E, Lao XY, Kapadia R, Swete M, Redpath JL. Neoplastic transformation in vitro by mixed beams of high-energy iron ions and protons. Radiat Res 2011; 176:291-302. [PMID: 21732791 DOI: 10.1667/rr2646.1] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The radiation environment in space is complex in terms of both the variety of charged particles and their dose rates. Simulation of such an environment for experimental studies is technically very difficult. However, with the variety of beams available at the National Space Research Laboratory (NSRL) at Brookhaven National Laboratory (BNL) it is possible to ask questions about potential interactions of these radiations. In this study, the end point examined was transformation in vitro from a preneoplastic to a neoplastic phenotype. The effects of 1 GeV/n iron ions and 1 GeV/n protons alone provided strong evidence for suppression of transformation at doses ≤5 cGy. These ions were also studied in combination in so-called mixed-beam experiments. The specific protocols were a low dose (10 cGy) of protons followed after either 5-15 min (immediate) or 16-24 h (delayed) by 1 Gy of iron ions and a low dose (10 cGy) of iron ions followed after either 5-15 min or 16-24 h by 1 Gy of protons. Within experimental error the results indicated an additive interaction under all conditions with no evidence of an adaptive response, with the one possible exception of 10 cGy iron ions followed immediately by 1 Gy protons. A similar challenge dose protocol was also used in single-beam studies to test for adaptive responses induced by 232 MeV/n protons and (137)Cs γ radiation and, contrary to expectations, none were observed. However, subsequent tests of 10 cGy of (137)Cs γ radiation followed after either 5-15 min or 8 h by 1 Gy of (137)Cs γ radiation did demonstrate an adaptive response at 8 h, pointing out the importance of the interval between adapting and challenge dose. Furthermore, the dose-response data for each ion alone indicate that the initial adapting dose of 10 cGy used in the mixed-beam setting may have been too high to see any potential adaptive response.
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Affiliation(s)
- E Elmore
- Department of Radiation Oncology, University of California Irvine, Irvine, California 92697, USA
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4
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Buonanno M, de Toledo SM, Azzam EI. Increased frequency of spontaneous neoplastic transformation in progeny of bystander cells from cultures exposed to densely ionizing radiation. PLoS One 2011; 6:e21540. [PMID: 21738697 PMCID: PMC3125249 DOI: 10.1371/journal.pone.0021540] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Accepted: 06/01/2011] [Indexed: 11/18/2022] Open
Abstract
An increased risk of carcinogenesis caused by exposure to space radiation during prolonged space travel is a limiting factor for human space exploration. Typically, astronauts are exposed to low fluences of ionizing particles that target only a few cells in a tissue at any one time. The propagation of stressful effects from irradiated to neighboring bystander cells and their transmission to progeny cells would be of importance in estimates of the health risks of exposure to space radiation. With relevance to the risk of carcinogenesis, we investigated, in model C3H 10T½ mouse embryo fibroblasts (MEFs), modulation of the spontaneous frequency of neoplastic transformation in the progeny of bystander MEFs that had been in co-culture 10 population doublings earlier with MEFs exposed to moderate doses of densely ionizing iron ions (1 GeV/nucleon) or sparsely ionizing protons (1 GeV). An increase (P<0.05) in neoplastic transformation frequency, likely mediated by intercellular communication through gap junctions, was observed in the progeny of bystander cells that had been in co-culture with cells irradiated with iron ions, but not with protons.
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Affiliation(s)
- Manuela Buonanno
- Department of Radiology, University of Medicine and Dentistry of New Jersey (UMDNJ), New Jersey Medical School Cancer Center, Newark, New Jersey, United States of America
- University of Medicine and Dentistry of New Jersey (UMDNJ), Graduate School of Biomedical Sciences, Newark, New Jersey, United States of America
| | - Sonia M. de Toledo
- Department of Radiology, University of Medicine and Dentistry of New Jersey (UMDNJ), New Jersey Medical School Cancer Center, Newark, New Jersey, United States of America
| | - Edouard I. Azzam
- Department of Radiology, University of Medicine and Dentistry of New Jersey (UMDNJ), New Jersey Medical School Cancer Center, Newark, New Jersey, United States of America
- University of Medicine and Dentistry of New Jersey (UMDNJ), Graduate School of Biomedical Sciences, Newark, New Jersey, United States of America
- * E-mail:
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5
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Stisova V, Abele WH, Thompson KH, Bennett PV, Sutherland BM. Response of primary human fibroblasts exposed to solar particle event protons. Radiat Res 2011; 176:217-25. [PMID: 21557667 DOI: 10.1667/rr2490.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Solar particle events (SPEs) present a major radiation-related risk for manned exploratory missions in deep space. Within a short period the astronauts may absorb doses that engender acute effects, in addition to the risk of late effects, such as the induction of cancer. Using primary human cells, we studied clonogenic survival and the induction of neoplastic transformation after exposure to a worst case scenario SPE. We simulated such an SPE with monoenergetic protons (50, 100, 1000 MeV) delivered at a dose rate of 1.65 cGy min⁻¹ in a dose range from 0 to 3 Gy. For comparison, we exposed the cells to a high dose rate of 33.3 cGy min⁻¹. X rays (100 kVp, 8 mA, 1.7 mm Al filter) were used as a reference radiation. Overall, we observed a significant sparing effect of the SPE dose rate on cell survival. High-dose-rate protons were also more efficient in induction of transformation in the dose range below 30 cGy. However, as dose accumulated at high dose rate, the transformation levels declined, while at the SPE dose rate, the number of transformants continued to increase up to about 1 Gy. These findings suggest that considering dose-rate effects may be important in evaluating the biological effects of exposure to space radiation. Our analyses of the data based on particle fluence showed that lethality and transforming potential per particle clearly increased with increasing linear energy transfer (LET) and thus with the decreasing energy of protons. Further, we found that the biological response was determined not only by LET but also type of radiation, e.g. particles and photons. This suggests that using γ or X rays may not be ideal for assessing risk associated with SPE exposures.
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Affiliation(s)
- Viktorie Stisova
- Biology Department, Brookhaven National Laboratory, Upton, New York 11973-5000, USA.
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Elmore E, Lao XY, Kapadia R, Redpath JL. Threshold-Type Dose Response for Induction of Neoplastic Transformation by 1 GeV/nucleon Iron Ions. Radiat Res 2009; 171:764-70. [DOI: 10.1667/rr1673.1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Elmore E, Lao XY, Kapadia R, Giedzinski E, Limoli C, Redpath JL. Low Doses of Very Low-Dose-Rate Low-LET Radiation Suppress Radiation-Induced Neoplastic TransformationIn Vitroand Induce an Adaptive Response. Radiat Res 2008; 169:311-8. [DOI: 10.1667/rr1199.1] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2007] [Accepted: 11/15/2007] [Indexed: 11/03/2022]
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8
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Lu H, Yue J, Meng X, Nickoloff JA, Shen Z. BCCIP regulates homologous recombination by distinct domains and suppresses spontaneous DNA damage. Nucleic Acids Res 2007; 35:7160-70. [PMID: 17947333 PMCID: PMC2175368 DOI: 10.1093/nar/gkm732] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Homologous recombination (HR) is critical for maintaining genome stability through precise repair of DNA double-strand breaks (DSBs) and restarting stalled or collapsed DNA replication forks. HR is regulated by many proteins through distinct mechanisms. Some proteins have direct enzymatic roles in HR reactions, while others act as accessory factors that regulate HR enzymatic activity or coordinate HR with other cellular processes such as the cell cycle. The breast cancer susceptibility gene BRCA2 encodes a critical accessory protein that interacts with the RAD51 recombinase and this interaction fluctuates during the cell cycle. We previously showed that a BRCA2- and p21-interacting protein, BCCIP, regulates BRCA2 and RAD51 nuclear focus formation, DSB-induced HR and cell cycle progression. However, it has not been clear whether BCCIP acts exclusively through BRCA2 to regulate HR and whether BCCIP also regulates the alternative DSB repair pathway, non-homologous end joining. In this study, we found that BCCIP fragments that interact with BRCA2 or with p21 each inhibit DSB repair by HR. We further show that transient down-regulation of BCCIP in human cells does not affect non-specific integration of transfected DNA, but significantly inhibits homology-directed gene targeting. Furthermore, human HT1080 cells with constitutive down-regulation of BCCIP display increased levels of spontaneous single-stranded DNA (ssDNA) and DSBs. These data indicate that multiple BCCIP domains are important for HR regulation, that BCCIP is unlikely to regulate non-homologous end joining, and that BCCIP plays a critical role in resolving spontaneous DNA damage.
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Affiliation(s)
- Huimei Lu
- Department of Radiation Oncology, The Cancer Institute of New Jersey, UMDNJ-Robert Wood Johnson Medical School, 195 Little Albany Street, New Brunswick, NJ 08903, USA
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9
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Elmore E, Lao XY, Kapadia R, Redpath JL. The effect of dose rate on radiation-induced neoplastic transformation in vitro by low doses of low-LET radiation. Radiat Res 2007; 166:832-8. [PMID: 17149982 DOI: 10.1667/rr0682.1] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2006] [Accepted: 08/15/2006] [Indexed: 11/03/2022]
Abstract
The dependence of the incidence of radiation-induced cancer on the dose rate of the radiation exposure is a question of considerable importance to the estimation of risk of cancer induction by low-dose-rate radiation. Currently a dose and dose-rate effectiveness factor (DDREF) is used to convert high-dose-rate risk estimates to low dose rates. In this study, the end point of neoplastic transformation in vitro has been used to explore this question. It has been shown previously that for low doses of low-LET radiation delivered at high dose rates, there is a suppression of neoplastic transformation frequency at doses less than around 100 mGy. In the present study, dose-response curves up to a total dose of 1000 mGy have been generated for photons from (125)I decay (approximately 30 keV) delivered at doses rates of 0.19, 0.47, 0.91 and 1.9 mGy/min. The results indicate that at dose rates of 1.9 and 0.91 mGy/min the slope of the induction curve is about 1.5 times less than that measured at high dose rate in previous studies with a similar quality of radiation (28 kVp mammographic energy X rays). In the dose region of 0 to 100 mGy, the data were equally well fitted by a threshold or linear no-threshold model. At dose rates of 0.19 and 0.47 mGy/min there was no induction of transformation even at doses up to 1000 mGy, and there was evidence for a possible suppressive effect. These results show that for this in vitro end point the DDREF is very dependent on dose rate and at very low doses and dose rates approaches infinity. The relative risks for the in vitro data compare well with those from epidemiological studies of breast cancer induction by low- and high-dose-rate radiation.
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Affiliation(s)
- E Elmore
- Department of Radiation Oncology, University of California Irvine, Irvine, California 92697, USA
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10
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Ko M, Lao XY, Kapadia R, Elmore E, Redpath JL. Neoplastic transformation in vitro by low doses of ionizing radiation: role of adaptive response and bystander effects. Mutat Res 2006; 597:11-7. [PMID: 16414089 DOI: 10.1016/j.mrfmmm.2005.08.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2005] [Revised: 08/12/2005] [Accepted: 08/19/2005] [Indexed: 10/25/2022]
Abstract
The shape of the dose-response curve for cancer induction by low doses of ionizing radiation is of critical importance to the assessment of cancer risk at such doses. Epidemiologic analyses are limited by sensitivity to doses typically greater than 50-100 mGy for low LET radiation. Laboratory studies allow for the examination of lower doses using cancer-relevant endpoints. One such endpoint is neoplastic transformation in vitro. It is known that this endpoint is responsive to both adaptive response and bystander effects. The relative balance of these processes is likely to play an important role in determining the shape of the dose-response curve at low doses. A factor that may influence this balance is cell density at time of irradiation. The findings reported in this paper indicate that the transformation suppressive effect of low doses previously seen following irradiation of sub-confluent cultures, and attributed to an adaptive response, is reduced for irradiated confluent cultures. However, even under these conditions designed to optimize the role of bystander effects the data do not fit a linear no-threshold model and are still consistent with the notion of a threshold dose for neoplastic transformation in vitro by low LET radiation.
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Affiliation(s)
- M Ko
- Department of Radiation Oncology, University of California Irvine, Irvine, CA 92697, USA
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11
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Ko SJ, Liao XY, Molloi S, Elmore E, Redpath JL. Neoplastic TransformationIn Vitroafter Exposure to Low Doses of Mammographic-Energy X Rays: Quantitative and Mechanistic Aspects. Radiat Res 2004; 162:646-54. [PMID: 15548114 DOI: 10.1667/rr3277] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The induction of neoplastic transformation in vitro after exposure of HeLa x skin fibroblast hybrid cells to low doses of mammography-energy (28 kVp) X rays has been studied. The data indicate no evidence of an increase in transformation frequency over the range 0.05 to 22 cGy, and doses in the range 0.05 to 1.1 cGy may result in suppression of transformation frequencies to levels below that seen spontaneously. This finding is not consistent with a linear, no-threshold dose- response curve. The dose range at which possible suppression is evident includes doses typically experienced in mammographic examination of the human breast. Experiments are described that attempt to elucidate any possible role of bystander effects in modulating this low-dose radiation response. Not unexpectedly, inhibition of gap junction intercellular communication (GJIC) with the inhibitor lindane did not result in any significant alteration of transformation frequencies seen at doses of 0.27 or 5.4 cGy in these subconfluent cultures. Furthermore, no evidence of a bystander effect associated with factors secreted into the extracellular medium was seen in medium transfer experiments. Thus, in this system and under the experimental conditions used, bystander effects would not appear to be playing a major role in modulating the shape of the dose-response curve.
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Affiliation(s)
- S J Ko
- Department of Radiation Oncology, University of California Irvine, Irvine, California 92697, USA
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Redpath JL, Liang D, Taylor TH, Christie C, Elmore E. The shape of the dose-response curve for radiation-induced neoplastic transformation in vitro: evidence for an adaptive response against neoplastic transformation at low doses of low-LET radiation. Radiat Res 2001; 156:700-7. [PMID: 11741493 DOI: 10.1667/0033-7587(2001)156[0700:tsotdr]2.0.co;2] [Citation(s) in RCA: 133] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A dose-response curve for gamma-radiation-induced neoplastic transformation of HeLa x skin fibroblast human hybrid cells over the dose range 0.1 cGy to 1 Gy is presented. In the experimental protocol used, the spontaneous (background) frequency of neoplastic transformation of sham-irradiated cultures was compared to that of cultures which had been irradiated with (137)Cs gamma radiation and either plated immediately or held for 24 h at 37 degrees C prior to plating, for assay for neoplastic transformation. The pooled data from a minimum of three repeat large-scale experiments at each dose demonstrated a reduced transformation frequency for the irradiated compared to the sham-irradiated cells for doses of 0.1, 0.5, 1, 5 and 10 cGy for the delayed-plating arm. The probability of this happening by chance is given by 1/2(n), where n is the number of observations (5); i.e., 1/32 congruent with 0.031. This is indicative of an adaptive response against spontaneous neoplastic transformation at least up to a dose of 10 cGy of gamma radiation. The high-dose data obtained at 30 and 50 cGy and 1 Gy showed a good fit to a linear extrapolation through the sham-irradiated, zero-dose control. The delayed-plating data at 10 cGy and below showed a statistically significant divergence from this linear extrapolation.
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Affiliation(s)
- J L Redpath
- Department of Radiation Oncology and Division of Epidemiology, University of California Irvine, Irvine, CA 92697, USA.
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Malyapa RS, Bisht KS, Ahern EW, Moros EG, Pickard WF, Straube WL. Neoplastic transformation in C3H 10T(1/2) cells after exposure to 835.62 MHz FDMA and 847.74 MHz CDMA radiations. Radiat Res 2001; 155:239-247. [PMID: 11121241 DOI: 10.1667/0033-7587(2001)155[0239:nticca]2.0.co;2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The effect of radiofrequency (RF) radiation in the cellular phone communication range (835.62 MHz frequency division multiple access, FDMA; 847.74 MHz code division multiple access, CDMA) on neoplastic transformation frequency was measured using the in vitro C3H 10T(1/2) cell transformation assay system. To determine if 835.62 MHz FDMA or 847.74 MHz CDMA radiations have any genotoxic effects that induce neoplastic transformation, C3H 10T(1/2) cells were exposed at 37 degrees C to either of the above radiations [each at a specific absorption rate (SAR) of 0.6 W/kg] or sham-exposed at the same time for 7 days. After the culture medium was changed, the cultures were transferred to incubators and refed with fresh growth medium every 7 days. After 42 days, the cells were fixed and stained with Giemsa, and transformed foci were scored. To determine if exposure to 835.62 MHz FDMA or 847.74 MHz CDMA radiation has any epigenetic effects that can promote neoplastic transformation, cells were first exposed to 4.5 Gy of X rays to induce the transformation process and then exposed to the above radiations (SAR = 0.6 W/kg) in temperature-controlled irradiators with weekly refeeding for 42 days. After both the 7-day RF exposure and the 42-day RF exposure after X irradiation, no statistically significant differences in the transformation frequencies were observed between incubator controls, the sham-exposed (maintained in irradiators without power to the antenna), and the 835.62 MHz FDMA or 847.74 MHz CDMA-exposed groups.
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Abstract
A reporter gene system that allows in situ detection of cells that have suffered a specific frameshift mutation was developed. To construct the reporter gene, the open reading frame of a human placental alkaline phosphatase (PLAP) gene was disrupted by insertion of either 5 or 7 G:C basepairs, which formed mutant alleles carrying 9 and 11 consecutive G residues, respectively. The mutant PLAP genes did not produce alkaline phosphatase activity in cultured mouse cells in transient transfection assays. Several cell lines that contained integrated copies of the mutant PLAP genes were made. Histochemical staining of fixed cells showed that these cell lines contained a small number of cells that expressed PLAP activity and bound antibodies directed against PLAP. Cells carrying the allele with 11 consecutive G residues (G11 allele) acquired PLAP activity at a rate between 2 x 10(-3) and 2 x 10(-4) events per cell per generation, depending on the cell line. Cells carrying the allele with 9 consecutive G residues (G09 allele) acquired PLAP activity at a rate between 2 x 10(-5) and 2 x 10(-6) events per cell per generation, depending on the cell line. Cultures of PLAP+ cells were derived from cell lines carrying PLAP mutant genes. All the cells in these cultures had PLAP activity and bound anti-PLAP antibody. PLAP mRNA levels were the same in cultures where all cells were PLAP+ and in cultures where less than 1% of the cells expressed PLAP activity. DNA sequence analysis of PLAP+ cells showed that the G11 allele reverted by losing one basepair, and the G09 allele reverted by gaining one basepair.
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Affiliation(s)
- J Cao
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, OH 45267-0524, USA
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