Effects Of X-rays Research Articles

Changes in ATPase activity, antioxidant enzymes and proline biosynthesis in yeast Candida guilliermondii NP-4 under X-irradiation.

This study investigates the effects of X-radiation on ATPase activity and antioxidant enzyme activity, particularly enzymes involved in proline biosynthesis, in yeast C. guilliermondii NP-4. Moreover, the study examined the post-irradiation repair processes in these cells. Results showed that X-irradiation at a dose of 300Gy led to an increase in catalase (CAT) and superoxide dismutase (SOD) activity, as well as, an increase in the CAT/SOD ratio in C. guilliermondii NP-4. The repair of radiation-induced damage requires a substantial amount of energy, resulting in an increased demand for ATP in the irradiated and repaired yeasts. Consequently, the total and FoF1-ATPase activity in yeast homogenates and mitochondria increased after X-irradiation and post-irradiation repair. It was showed an increase in the activity of proline biosynthesis enzymes (ornithine transaminase and proline-5-carboxylate reductase) in X-irradiated C. guilliermondii NP-4, which remained elevated even after post-irradiation repair. As a result, the proline levels in X-irradiated and repaired yeasts were higher than those in non-irradiated cells. These findings suggest that proline may have a radioprotective effect on X-irradiated C. guilliermondii NP-4 yeasts. Taken together this study provides insights into the effects of X-radiation on ATPase activity, antioxidant enzyme activity, and proline biosynthesis in C. guilliermondii NP-4 yeast cells, highlighting the potential radioprotective properties of proline in X-irradiated yeasts.

Vitexin Glucolone Reinforces Radiosensitivity of Non-Small Cell Lung Cancer via Transforming Growth Factor Kinase 1/Adenylate Activated Protein Kinase Signaling Pathway

Purpose: To discuss effects of vitexin glucolone (VG) to radiosensitivity of NSCLC (Non-small cell lung cancer) cell lines (A549 and H1299). Methods: Treating A549 and H1299 cells by VG with or without X-radiation. Cell viability was calculated by CCK8. Apoptosis rate was measured by flow cytometry and Western blot to expressions of protein. Subsequently, cells were transferred with TAK1 siRNA, cell viability and apoptosis were measured. Results: VG decreased the viability of Huh7 cells and inhibited effects of VG was more strengthen than radiotherapy in concentrations of 20 μmol/L and 40 μmol/L. Meanwhile, VG sensitized HCC exposed to radiation therapy to apoptosis as demonstrated by increased Bax/Bcl-2 ratio. In addition, VG enhanced the promotive effects of X-radiation on the expressions of TAK1, AMPKα1 and PPARγ. Furthermore, silence the expression of TAK1 partly reversed the effects of VG on HCC and radiosensitivity of NSCLC. Conclusion: VG enhances radiosensitivity of NSCLC via TAK1/AMPK pathway.

An investigation of the effects of N-acetylcysteine on radiotherapy-induced testicular injury in rats.

According to data issued by the International Agency for Research on Cancer in 2012, the estimated number of new cases of all types of cancer worldwide was estimated to exceed 10 million, and 6 million of whom receive radiotherapy. Radiotherapy is the treatment of cancer using ionizing radiation. Our study investigated the effects of x-radiation resulting from radiotherapy (RT) on the testis at the molecular level, and prospectively considered the potential protective characteristics of antioxidants against testicular damage resulting from x-radiation. Forty male Sprague Dawley rats were allocated into five groups, control (group 1), abdominopelvic region 2-Gy-ionizing radiation (group 2), whole-body 6-Gy irradiation (group 3), 2Gy abdominopelvic region irradiation and 300mg/kg NAC treatment (group 4), and 6-Gy whole-body irradiation and 300mg/kg NAC treatment (group 5). Disorganization and vacuolization were observed in the epithelial layer in atrophic seminiferous tubules in the only ionizing radiation (IR) groups. In addition, Johnsen's score decreased in the only IR groups, while testis tissue malondialdehyde (MDA) and glutathione (GSH) tissue levels increased. N-Acetylcysteine (NAC) treatment groups Johnsen's score and tissue GSH levels increased than only IR groups. On the other hand, tissue MDA levels decreased in the NAC treatment groups. The findings showed that ionizing radiation caused apoptosis in germinal epithelial cells led to the oxidative stress-mediated testicular injury. On the other hand, NAC may be useful in the prevention of testicular injury-suppressed ROS production.

Effect of Alendronate on Bone Microarchitecture in Irradiated Rats With Osteoporosis: Micro-CT and Histomorphometric Analysis

The aim of the present study was to evaluate the effect of alendronate (ALN) on the bone microarchitecture of irradiated rats with estrogen deficiency, using microcomputed tomography (micro-CT) and histomorphometric analysis. Forty adult Wistar rats were subjected to ovariectomy and randomly divided into the following groups: control (CON), ALN, irradiated (IRR), and ALN/irradiated (ALN/IRR). Approximately 50days after ovariectomy, the hind limbs of the rats in the IRR and ALN/IRR groups were irradiated with 15Gy of x-radiation. The rats were euthanized 7 and 30days after irradiation. The bone microarchitecture was analyzed using micro-CT and histomorphometry. The bone microarchitecture was evaluated using the Mann-Whitney U test, analysis of variance, and the post hoc Tukey test, with statistical significance set at 5%. Irradiation had increased the thickness of the cortical bone at 7days (P<.05) and also decreased the number of trabeculae per unit length and increased the average distance between the trabeculae (P<.05) at 30days. ALN inhibited the deleterious effect of x-radiation, preventing the distance between the trabeculae from increasing and the number of trabeculae per unit length from decreasing (P<.05). The present results have demonstrated that the initial effect of ALN could be positive, because it checked the deleterious action in the bone tissue submitted to x-radiation.

Evaluation of the radiosensitizing potency of chemotherapeutic agents in prostate cancer cells

Purpose: Despite recent advances in the treatment of metastatic prostate cancer, survival rates are low and treatment options are limited to chemotherapy and hormonal therapy. Although ionizing radiation is used to treat localized and metastatic prostate cancer, the most efficient use of radiotherapy is yet to be defined. Our purpose was to determine in vitro the potential benefit to be gained by combining radiation treatment with cytotoxic drugs.Materials and methods: Inhibitors of DNA repair and heat shock protein 90 and an inducer of oxidative stress were evaluated in combination with X-radiation for their capacity to reduce clonogenic survival and delay the growth of multicellular tumor spheroids.Results: Inhibitors of the PARP DNA repair pathway, olaparib and rucaparib, and the HSP90 inhibitor 17-DMAG, enhanced the clonogenic cell kill and spheroid growth delay induced by X-radiation. However, the oxidative stress-inducing drug elesclomol failed to potentiate the effects of X-radiation. PARP inhibitors arrested cells in the G2/M phase when administered as single agents or in combination with radiation, whereas elesclomol and 17-DMAG did not affect radiation-induced cell cycle modulation.Conclusion: These results indicate that radiotherapy of prostate cancer may be optimized by combination with inhibitors of PARP or HSP90, but not elesclomol.

X-radiation enhances the collagen type I strap formation and migration potentials of colon cancer cells.

Rectal cancer treatment still fails with local and distant relapses of the disease. It is hypothesized that radiotherapy could stimulate cancer cell dissemination and metastasis. In this study, we evaluated the effect of X-radiation on collagen type I strap formation potential, i.e. matrix remodeling associated with mesenchymal cell migration, and behaviors of SW480, SW620, HCT116 p53+/+ and HCT116 p53−/− colon cancer cells. We determined a radiation-induced increase in collagen type I strap formation and migration potentials of SW480 and HCT116 p53+/+. Further studies with HCT116 p53+/+, indicated that after X-radiation strap forming cells have an increased motility. More, we detected a decrease in adhesion potential and mature integrin β1 expression, but no change in non-muscle myosin II expression for HCT116 p53+/+ after X-radiation. Integrin β1 neutralization resulted in a decreased cell adhesion and collagen type I strap formation in both sham and X-radiated conditions. Our study indicates collagen type I strap formation as a potential mechanism of colon cancer cells with increased migration potential after X-radiation, and suggests that other molecules than integrin β1 and non-muscle myosin II are responsible for the radiation-induced collagen type I strap formation potential of colon cancer cells. This work encourages further molecular investigation of radiation-induced migration to improve rectal cancer treatment outcome.

Fentanyl Iontophoretic Transdermal System (IONSYS(®)) can be Safely used in the Hospital Environment with X-Rays, Computerized Tomography and Radiofrequency Identification Devices.

IntroductionFentanyl iontophoretic transdermal system (fentanyl ITS, IONSYS®) is a patient-controlled analgesia system used for the management of acute postoperative pain, designed to be utilized in a hospital setting. The objective of the two studies was to determine if fentanyl ITS could be safely used with X-rays, computerized tomography (CT) scans and radiofrequency identification (RFID) devices.MethodsThe ITS system has two components: controller and drug unit; the studies utilized ITS systems without fentanyl, referred to as the ITS Placebo system. The first study evaluated the effect of X-radiation on the operation of an ITS Placebo system. Five ITS Placebo systems were exposed to X-rays (20 and 200 mSv total radiation dose—the 200 mSv radiation dose represents a tenfold higher exposure than in clinical practice) while operating in the Ready Mode and five were exposed while operating in the Dose Mode. The second study evaluated the effect of RFID (worst-case scenario of direct contact with an RFID transmitter) on the operation of an ITS Placebo system. During these tests, observations of the user interface and measurements of output voltage confirmed proper function throughout all operational modes (Ready Mode, Dose Mode, End-of-Use Mode, and End-of-Life Mode).ResultsThe ITS Placebo system met all specifications and no functional anomalies were observed during and following X-ray exposure at two radiation dose levels or exposure at six different combinations of RFID frequencies and field strengths.ConclusionThe performance of the ITS system was unaffected by X-ray exposure levels well beyond those associated with diagnostic X-rays and CT scans, and by exposure to radiofrequency field strengths typically generated by RFID devices. These results provide added confidence to clinicians that the fentanyl ITS system does not need to be removed during diagnostic X-rays and CT scans and can also be utilized in close proximity to RFID devices.FundingThe studies and writing of this manuscript were supported financially by The Medicines Company.

Effects of X-radiation on lung cancer cells: the interplay between oxidative stress and P53 levels.

Lung cancer (LC) ranks as the most prevalent and deadliest cause of cancer death worldwide. Treatment options include surgery, chemotherapy and/or radiotherapy, depending on LC staging, without specific highlight. The aim was to evaluate the effects of X-radiation in three LC cell lines. H69, A549 and H1299 cell lines were cultured and irradiated with 0.5-60 Gy of X-radiation. Cell survival was evaluated by clonogenic assay. Cell death and the role of reactive oxygen species, mitochondrial membrane potential, BAX, BCL-2 and cell cycle were analyzed by flow cytometry. Total and phosphorylated P53 were assessed by western blotting. Ionizing radiation decreases cell proliferation and viability in a dose-, time- and cell line-dependent manner, inducing cell death preferentially by apoptosis with cell cycle arrest. These results may be related to differences in P53 expression and oxidative stress response. The results obtained indicate that sensibility and/or resistance to radiation may be dependent on molecular LC characteristics which could influence response to radiotherapy and treatment success.

Effects of X-rays on Tuta absoluta for use in inherited sterility programmes

Tuta absoluta is a key pest of tomato crops originating from South America. The consequences of X-radiation on this species were studied under laboratory controlled conditions. The effect of radiation on adult emergence was evaluated exposing male and female pupae to increasing X-rays. Adult emergence decreased as doses of X-radiation increased, with the appearance of deformities such as malformed wings and bent legs at doses ≥350 Gy. Besides, males and females obtained from irradiated pupae were out crossed with untreated counterparts to explore the effects of X-radiation on inherited sterility. (a) Irradiated male × untreated female crosses. Both fecundity and fertility of the untreated females were reduced by radiation, and the effect was stronger as the doses increased. Neither the longevity of parental males and F1 adults nor the sex ratios of the F1 and F2 generations were affected by X-radiation (F1 and F2: first and second generation of descendants of irradiated adults). Inherited sterility effects were manifested by a significant reduction in the F1 fecundity, F1 fertility, and the amount of larvae and pupae produced. Doses of 200–250 Gy could be used to induce inherited sterility in T. absoluta males. (b) Untreated male × irradiated female crosses. The minimum dose at which irradiated females were completely sterile was 200 Gy. The present study is the first study in T. absoluta that provides the starting point for implementing the inherited sterility in this species.

WHOLE-BODY IONIZING IRRADIATION INCREASES AORTIC STIFFNESS AND STIFFNESS SENSITIVITY TO HIGH BLOOD PRESSURE IN RATS: PP.10.402

Objective: The cardiovascular effects of ionizing radiation are mediated through inflammatory mechanisms affecting endothelial function and arterial extracellular matrix (ECM) leading to alteration of arterial stiffness and pulse wave velocity (PWV). This study aims to determine the effects of X-radiation on aortic PWV in rats and and change in sensitivity of PWV to MP. Methods: Male Sprague-Dawley rats (14 weeks) were exposed to a single high-dose of high-energy X-ray (source: LINAC, 6 MV) at 0 (control) or 5 Gy (irradiated). Between 0 to 24 hours, 24 to 48 hours and 3 weeks following irradiation, rats were anaesthetized (1.3 g/kg, urethane) and beat-to-beat aortic PWV and MP measured invasively using two 1.3 F high fidelity pressure sensors. MP was increased and decreased over the range of 60–150 mmHg with intravenous infusion of phenylephrine (0.2 mg/kg/min) and sodium nitroprusside (0.05 mg/kg/min) respectively. Results: Mean aortic PWV in irradiated rats measured within 24 hours post-irradiation was 5.08 ± 0.15 m/s (n = 6), a 14% increase compared to the control group (4.44 ± 0.11 m/s; n = 6; P < 0.05). No significant difference was observed between PWV in the irradiated group measured in the 24–48 hour period post-irradiation and control or 3 weeks post radiation. PWV-MP sensitivity (m/sec/10mmHg) determined from the slope of the PWV-MP curves was similar for both control (0.10 ± 0.01 (SE)) and irradiated rats (0.11 ± 0.01) for the low pressure range (MP 60–100 mmHg) but significantly different for the high pressure range (100–150 mmHg) only for the first 24 hour period (control 0.27 ± 0.02; irradiation: 0.37 ± 0.03; p < 0.05). Conclusions: Findings indicate an acute and marked increase in aortic stiffness and pressure dependency of aortic stiffness due to radiation at mean pressure values above normal resting pressure in rats. This may be related to differential effects of radiation induced inflammation-mediated mechanisms on active (cellular and molecular) and passive (ECM) components involved in regulation of arterial stiffness.

Spectral analysis of paramagnetic centers induced in human tooth enamel by x-rays and gamma radiation

Based on study of spectral and relaxation characteristics, we have established that paramagnetic centers induced in tooth enamel by x-rays and gamma radiation are identical in nature. We show that for the same exposure dose, the intensity of the electron paramagnetic resonance (EPR) signal induced by x-radiation with effective energy 34 keV is about an order of magnitude higher than the amplitude of the signal induced by gamma radiation. We have identified a three-fold attenuation of the EPR signal along the path of the x-radiation from the buccal to the lingual side of a tooth, which is evidence that the individual had undergone diagnostic x-ray examination of the dentition or skull. We have shown that the x-ray exposure doses reconstructed from the EPR spectra are an order of magnitude higher than the applied doses, while the dose loads due to gamma radiation are equal to the applied doses. The data obtained indicate that for adequate reconstruction of individual absorbed doses from EPR spectra of tooth enamel in the population subjected to the combined effect of x-radiation and accidental external gamma radiation as a result of the disaster at the Chernobyl nuclear power plant, we need to take into account the contribution to the dose load from diagnostic x-rays in examination of the teeth, jaw, or skull.

Proteome analysis of X-ray irradiated human erythroleukemia cells

In order to discover molecular biomarkers in radiation response we investigated the effects of X-radiation on radioresistant K562 cells by using a comparative proteomic analysis. In treated cells 29 up-regulated and 10 down-regulated proteins were detected by image analysis and identified by mass spectrometry. Elongation factor 1 alpha 1 and stress-70 protein showed a 6.2 and 5.4 fold increase respectively in treated cells. Additional proteins such us pi and omega classes glutathione transferases, ATP synthase D chain, were also found to be up-regulated, suggesting that the enzyme belonging to the cellular detoxification system against oxidative stress and energetic metabolism may have a key role in the cellular response to radiation injury. This data set may provide a useful tool to design a combined chemo- and radiotherapic strategy against leukemia disease.

Pycnogenol® protects against Ionizing radiation as shown in the intestinal mucosa of rats exposed to X‐rays

X-rays and gamma radiation delivered to the abdominal region for cancer treatment encompasses severe damage to the intestinal mucosa, which significantly impairs a patient's quality of life. To a great extent the deleterious effects of x-radiation originate from radiolysis-induced reactive oxygen species. The well-researched powerful antioxidant Pycnogenol was administered orally to rats prior to x-irradiation with 15 Gy. Histological sections of the intestines showed a dramatically better condition of the mucosal layers compared with the irradiated control animals administered water without Pycnogenol. Pycnogenol treatment significantly preserved the height and number of villi as well as the glandular layer and a diminished number of congested vases were present. No intestinal alterations were seen in control animals receiving Pycnogenol in the absence of radiation. It is concluded that Pycnogenol provides significant protection from ionizing radiation damage.

Changes of hMSH2 and hMLH1 Expression in Nasopharyngeal carcinoma cells after X-radiation

Objective To study the effect of X-radiation on expression of hMSH2 and hMLH1 in nasopharyngeal carcinoma (NPC) CNE-1 cells, and explore the mechanism of DNA mismatch repair after radiation.

The effect of close binary evolution on photoionization models for evolving starbursts

Using a population number synthesis code and detailed massive star evolutionary calculations, Van Bever & Vanbeveren (1998) investigated the effect of close binary evolution on the WR and O-type star population of starburst regions. It was concluded that the age determination based on O-type features of a starburst which is older than 4 million years could be erroneous if observations are interpreted from the point of view of single star evolution only. Most important is the formation of rejuvenated OB-type Blue Stragglers when significant matter lost by the binary primary during the Roche lobe overflow (RLOF), is accreted by the companion. The present paper illustrates the latter statement. We consider the most frequently used age determinators, i.e., the strength of the H α and H β emission lines of starburst regions. We distinguish the effects of the OB-type Blue Stagglers, of WR single stars and of hydrogen deficient core helium burning binary components in the post-RLOF phase of evolution (including the WR binary components) and the effects of X-radiation produced in standard high mass X-ray binaries.

X-radiation induces 8-hydroxy-2'-deoxyguanosine formation in vivo in rat mammary gland DNA.

Ionizing radiation is a carcinogen that induces oxidative DNA damage. 8-Hydroxy-2'-deoxyguanosine (8-OHdG) is a relatively abundant, mutagenic lesion that is widely regarded as a reliable index of oxidative DNA damage. The purpose of this study was to examine the effects of X-radiation on levels of 8-OHdG in the context of an experimental model for breast cancer in which chronic radiation exposure has been shown to be carcinogenic in Sprague-Dawley rats. A secondary objective of this study was to determine if the use of phenol during DNA isolation affected the concentration of 8-OHdG subsequently measured. Our results indicate that a profoundly carcinogenic dose of radiation induced a small but significant increase in 8-OHdG concentration in mammary gland DNA, and that the use of a phenol-based versus a salt-based method of DNA isolation had no significant impact on the levels of 8-OHdG detected in either control or irradiated tissue.

The effect of X-radiation on cerebellar granule cells grown in culture. Ganglioside GM1 neuroprotective activity

In this paper we describe the effects of X-radiation on the viability of cerebellar granule cells grown in culture. Cell cultures were exposed to X-rays 2 h after plating and then grown for 1–7 days. Two days after X-ray exposure with a dose-range of 0.1–2 Gy (acute effect), a significant decrease in neuronal number was observed. The magnitude of the lethal effect was directly correlated to the dose of X-ray applied. When the interval between plating and irradiation was increased, the acute lethal effect of X-rays decreased. 3H-thymidine incorporation was maximal during the first 24 h in vitro and decreased to nearly blank levels, after 72 h. In some experiments, cells present in each culture dish were counted at day 2 and at day 7. We observed that the number of cells present in sham-irradiated cultures decreased from day 2 to day 7, reflecting cell death after several days in vitro. The cell loss observed in X-irradiated cultures was significantly greater as compared with sham-irradiated cultures, confirming the deleterious effect of X-ray on cell survival. This effect was completely prevented by GM1 (6.5, 10 and 30 μM) added 48 h after X-ray exposure, but not 1 h after plating. We conclude that X-rays induce two different effects: an acute effect related to impaired DNA synthesis which is very active during the first 24 h in vitro, and a long-term effect owing to a sublethal damage in the surviving neuronal population.

The effect of x-radiation upon the quality and fertility of stallion semen

The exposure that stallion semen might receive during examination using an airport x-ray security screening system was found to be between 0.5 and 1.0 micro Sieverts (μSv). Ejaculates from 2 stallions were diluted 1:4 (volume:volume) using a nonfat dried milk-glucose extender. A total of 6 ejaculates from each stallion was collected, and each ejaculate was divided into 3 aliquots and these were then exposed to x-radiation at a dose of 0, 1.0, or 10.0 (μSv. Semen quamy was examined immediately post exposure, and the aliquots were then placed into a water bath at 37 °C, after which sample longevity was evaluated. In a second trial, 3 groups of 8 pony mares were inseminated with semen that had been exposed to x-radiation at doses of 0, 1.0, or 10.0 μSv. An entire ejaculate was irradiated and inseminated into each mare on one occasion during estrus, based upon ultrasonographic evaluation of the reproductive tract. After exposure to x-radiation there were no differences among the 3 treatment groups for spermatozoal motility, morphology, or longevity. The 14-d pregnancy rates for the 3 treatment groups were 0 μSv (7 mares), 1.0 μSv (8 mares), and 10.0 μSv (7 mares). One mare (0 (μSv) aborted at 65 d of pregnancy; 21 mares had a pregnancy of normal length, with each delivering a foal at term, although 1 foal died at parturition (1.0 μSv). These findings indicate that the exposure of stallion spermatozoa to x-radiation up to doses of 10 μSv does not have deleterious effects upon spermatozoal motility, morphology, longevity or fertility. The exposure received during examination using an x-ray security screening system is likely to be lower than this dose.

The effect of X-radiation on the plastic deformation of ice

The results of tensile tests on ice single crystals performed with and without X-ray irradiation show that X-radiation does not measurably affect the creep deformation of ice. Therefore, the dislocation mobility and dislocation mechanisms observed by X-ray topography represent the intrinsic behaviour of ice.

Synaptonemal complex aberrations in the pseudoautosomal region of X, Y chromosomes in irradiated hamsters.

The effects of X-radiation, bleomycin and amsacrine (m-AMSA) on the meiotic chromosomes of male Armenian hamsters were determined by electron microscopic analysis of synaptonemal complex (SC) damage. Pachytene stage cells were analyzed 5 or 6 days following their treatment at putative preleptotene-leptotene stages of meiosis. Of the multiple types of SC aberrations observed to be significantly increased over control levels, lateral element breakage and synaptic anomalies were most prevalent. The focus of these studies was on the sex chromosomes which, in the Armenian hamster, reveal an unusually well-defined pseudoautosomal region. In the XY pair, radiation and chemical treatments caused certain forms of structural and synaptic anomalies which appeared to be preferentially localized to telomeric and/or crossover regions. The nature of these specific aberrations, involving breakage, bridge formation and asynapsis, is not well understood; however, their distributions are suggestive of possible relationships with sites and processes of crossing over.